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ABSTRACTS
Year : 2019  |  Volume : 34  |  Issue : 5  |  Page : 23-109  

Abstracts


Date of Web Publication26-Nov-2019

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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0972-3919.271608

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How to cite this article:
. Abstracts. Indian J Nucl Med 2019;34, Suppl S1:23-109

How to cite this URL:
. Abstracts. Indian J Nucl Med [serial online] 2019 [cited 2019 Dec 14];34, Suppl S1:23-109. Available from: http://www.ijnm.in/text.asp?2019/34/5/23/271608




   Oral Presentation: Oncology Top



   OP1: Evaluation of 131I-MIBG scintigraphy and 18F-DOPA positron emission tomography/computed tomography in neuroblastoma-initial results Top


Angel Hemrom, Meghana Prabhu, Avinash Tupalli, Arunav Kumar, Sandeep Agarwala1, Rachna Seth2, Sameer Bakhshi3, Nishikant Avinash Damle, Chandrasekhar Bal

Departments of Nuclear Medicine, 1Pediatric Surgery, 2Pediatrics and 3Medical Oncology, All India Institute of Medical Sciences, New Delhi, India.

Aim: Neuroblastoma, one of the most common pediatric malignancy presents with metastatic disease in more than half of patients at presentation. 131I-MIBG scintigraphy and 18F-DOPA PET/CT are established modalities in evaluation of neuroblastoma. We compared 131I-MIBG and 18F-DOPA PET/CT in picking up the culprit lesions. We also used standardized scoring methods in both the modalities to assess disease extent in the patients. Materials and Methods: 21 biopsy proven neuroblastoma patients underwent 131I-MIBG scan following 48-72 hours of 37±12 MBq intravenous administration of 131I-MIBG. Planar images were obtained from head to toe. Single photon emission computed tomography/Computed tomography (SPECT/CT) of the region of interest were performed. All patients underwent 18F-DOPA PET/CT within 1 month of 131I-MIBG scan, after 45-60 min of 5 MBq/kg intravenous administration of 18F-DOPA. Images were acquired from head to toe at minimum 2 min per bed position. Number of lesions detected in planar 131I-MIBG vs MIP image of 18F-DOPA and SPECT/CT vs fused PET/CT images were correlated. Evaluation of disease extent was done using semi-quantitative Curie and SIOPEN systems and correlation between the same were assessed. Results: Out of 21 patients,14 were males and 7 females. Mean age was 2.8 years (4 months to 7 years). Patient were staged according to INRGSS staging (L=4, L2=7, M=8, MS=2). MYCN gene evaluation was done in 2 patients (1=positive, 1=negative). Indication of the study were baseline evaluation in 17 and restaging in 4 patients. Biochemically in 11 patients urinary catecholamines were elevated. Bone marrow biopsy was performed in 16 patients, out of which 8 were positive and 8 were negative. Both 131I-MIBG and 18F-DOPA PET/CT scan was positive in 20 patients and negative in 1 patient. Planar 131I-MIBG v/s MIP 18F-DOPA identified 126 v/s 177 total no. of lesions (Pearson's coefficient, r = 0.72). SPECT/CT 131I-MIBG v/s fused PET/CT 18F-DOPA identified 100 v/s 185 total no. of lesions (r = 0.59). Higher number of bone/bone marrow lesions were picked up on 18F-DOPA PET/CT. Strong agreement in describing the disease extent was noted between 131I-MIBG and 18F-DOPA in both Curie (r = 0.84) and SIOPEN scoring (r = 0.86). Interestingly 2 patients had lesions which were extensively MIBG avid but was sparsely positive in 18F-DOPA and vice-versa in 1 patient. Conclusion: Total number of lesions picked up were more in 18F-DOPA MIP and corresponding PET/CT images in comparison to 131I-MIBG planar and SPECT/CT images respectively.


   OP2: Role of texture parameters derived on 18F-flourodeoxyglucose positron emission tomography/computed tomography studies, in prediction of response to therapy in breast carcinoma patients Top


Nivedita Rana, Bhagwant Rai Mittal, Kanhaiyalal Agrawal, Devinder Kumar Dhawan

Department of Nuclear Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

Aim: Texture analysis is an emerging tool for evaluation of tumor uptake in PET studies. The aim of the present study was to see whether or not texture parameters derived on 18F-FDG PET/CT can predict therapy response in breast carcinoma patients. Methodology: A total of 45 female patients (46.88 ± 10.92 y) with biopsy proven breast carcinoma, referred for 18F-FDG PET/CT study were included. These patients underwent pre-therapy 18F-FDG PET/CT study before undergoing any treatment and subsequently were treated with 8 cycles of chemotherapy. These patients underwent post-therapy 18F-FDG PET/CT for evaluation of response to therapy. Texture analysis was performed on pre-therapy 18F-FDG PET/CT studies using a software package based on MATLAB (CGITA-Chang-Gung Image Texture Analysis toolbox). Total of 59 texture parameters based on gray level co-occurrence matrix (GLCM), normalised gray level co-occurrence matrix (NGLCM), neighbouring gray-tone difference matrix (NGTDM), gray level run length matrix (GLRLM), gray level size zone matrix (GLSZM), texture spectrum method (TS), texture feature coding method (TFCM), texture feature coding co-occurrence matrix (TFCCM) and neighbouring gray level dependence matrix (NGLDM) were obtained. The patients were classified on the basis of their response to therapy as complete responder (CR), partial responder (PR) and non-responder (NR) according to PERCIST criteria. Normality of texture parameters was analysed using Kolmogorov–Smirov test. The parameters with p ≥ 0.05 were considered normal. Ability of texture parameters to discriminate patient groups according to their response to treatment (CR vs PR vs PD) and (PD vs CR + PR) was studied using one-way Annova test and t-test respectively, for normally distributed parameters; and Kruskal-Wallis test and Mann-Whitney U test respectively for not normally distributed parameters. The difference was considered significant for p <0.05. Results: All texture parameters had p > 0.05 for one-way Annova test, t-test, Kruskal-Wallis test and Mann-Whitney U test. None of the texture parameters had significant difference in patient groups classified according to their response (CR vs. PR vs. PD or CR + PR (responders) vs. PD (non-responders) and hence were not able to significantly classify patients according to their response to treatment. Conclusion: Though use of texture parameters as a predictor of response and survival in various carcinomas is increasing these days, but as per our study texture parameters were not able to predict response to therapy in breast carcinoma patients.


   OP3: Patterns of 18F-flourodeoxyglucose positron emission tomography-computed tomography findings in patients with thymic masses Top


Suneel Kumar Malipedda, Ankur Pruthi

Department of Nuclear Medicine, Sir Gangaram Hospital, Delhi, India.

Background: Thymic epithelial tumours are the most common anterior mediastinal masses. 18F-Flourodeoxyglucose (18F-FDG) positron emission tomography-computer tomography (PET-CT) has gained widespread popularity in oncological imaging and being used for staging, restaging, response monitoring and prognostication of various tumors. Pre-treatment diagnosis of thymic masses is useful for planning the treatment and prognostication. Aim and Objectives: The purpose of this study is to study patterns of F-18 FDG PET CT findings in patients with thymic masses. Materials and Methods: We prospectively analyzed PET CT scan findings and histopathological findings in patients with thymic masses from August 2016 to March 2018. We included patients with anterior mediastinal masses consistent with thymic etiology. PET CT findings were analyzed by 2 experienced Nuclear medicine physicians. Histopathological reports were collected. We on the basis of histopathological findings, classified patients into 3 simplified groups based on WHO classification as low risk thymomas (WHO types A, AB, B1), high risk thymomas (types B2 and B3) and thymic carcinomas. We studied pattern of FDG uptake in these 3 groups. Results: Between August 2016 and March 2018, thirty-one consecutive patients (19 males, 12 females, and mean Age 49 ± 9.4 years, Range 29-65 years) with anterior mediastinal masses, consistent with thymic origin who underwent F-18 FDG PET CT study in our Nuclear Medicine department for pretreatment evaluation were enrolled in this study. Out of 31 patients, 12 patients were operated at our hospital. Other patients were managed elsewhere, however the histopathology reports of all 31 patients were collected and correlated with FDG PET CT scan findings. Histopathology revealed 6 low risk thymoma, 10 high risk thymoma and 15 thymic carcinomas. Mean SUVmax of low risk, high risk and thymic carcinomas were 4.06 ± 0.8, 5.14 ± 1.2, 10.83 ±1.14 respectively. We found that there was significant difference in the SUVmax of low risk thymoma and thymic carcinoma (p <0.05) and high risk thymoma and thymic carcinoma (p value<0.05) subgroups. We haven't found any significant difference between SUVmax of low risk thymoma and high risk thymoma (p < 0.07). Pattern of FDG uptake is predominately homogenous in thymic carcinoma subgroup and heterogenous in low risk and high risk thymomas. Conclusion: F-18 FDG PET CT scan may help in differentiating low-risk and high risk thymoma from thymic carcinoma based on SUVmax and pattern of FDG uptake. F-18 FDG PET CT scan is also useful in pre-treatment staging and evaluation of extent of disease.


   OP4: Role of 18F-flourodeoxyglucose positron emission tomography/computed tomography in diagnosis of paraneoplastic syndrome Top


Shamim Ahmed Shamim, Geetanjali Arora, Shashwat Somani, Meivel Angamuthu, S. T. Arun Raj, Madhavi Tripathi, Rakesh Kumar, Nishikant Avinash Damle, Chandrasekhar Bal

Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India.

Aim: Paraneoplastic syndrome is a rare condition that is most often triggered by an altered immune system response to a neoplasm. It may involve autoimmune mechanism alongwith non-metastatic systemic effects accompanying malignant disease. However, paraneopastic syndrome suffers diagnostic challenge owing to its varied presentation. We aim to evaluate the role of 18F-FDG PET/CT in diagnosis of paraneoplastic syndrome. Materials and Methods: Patients with clinically proven/suspected paraneoplastic syndrome, referred to our department for 18F-FDG PET/CT scan from 2018 to 2019 to look for any malignant etiology were retrospectively analyzed. Scans were reported by two experienced nuclear medicine physicians. Histopathology and/or clinical follow up were taken as reference standard. Results: During this period, total 271 patients with clinically proven/suspected paraneoplastic syndrome were included in the study. Mean age of patients was 51±17.3 years (range: 16-92 years). Of these, 30 patients were found to have metabolically active lesion on PET/CT scan. Site of positive lesions were: brain (4); lymph nodes (8); thorax (6; lung and pleura=3; mediastinum=1; trachea=1; diaphragm=1); abdomen (3); breast (3); bone (3); thyroid (1); nose (1) and adnexa (1). 17 of 30 patients (57%) were true positive while 5 were false positive (17%). In 8 patients histopathology or the clinical follow up data were not available. Conclusion: PET/CT may be useful in detection or exclusion of malignancy in patients with paraneoplastic syndrome.


   OP5: Utility of 68Ga-PSMA positron emission tomography/computed tomographyin biopsy proven early low and intermediate grade Prostate carcinoma and comparison with mpMRI – Single institutional experience Top


G. Dinesh Kumar, Meenu Mohan, Priyanka Korepu, Rajlaxmi Jagtap, Shreyas Kudachi, Hemant Rathore, Sachin Arora, Vishnu Hari, Pankaj Kumar, Karuna Luthra, Vikram Lele

Department of Nuclear Medicine and PET/CT, Jaslok Hospital and Research Centre, Mumbai, Maharashtra, India.

Aim: Early detection and precise staging of Prostate carcinoma (PCa) is of utmost importance for prognosis assessment and treatment planning. There is variation in its aggressiveness based on pathological Gleason's grade. Traditionally mpMRI has been used for early detection of primary PCa detection. However 68Ga-PSMA PET/CT scan is now gaining foothold even for early detection. Our aim was to study the sensitivity of 68Ga-PSMA PET/CT in comparison with mpMRI in detection and staging of low and intermediate Gleason's grade PCa including Gleason's scores 3+3, 3+4 and 4+3.

Materials and Methods: 25 patients with biopsy proven PCa who had mpMRI for detection and initial staging were enrolled in this study and underwent 68Ga-PSMA PET/CT scan. Both 68Ga-PSMA PET/CT and mpMRI findings were compared to the preoperative histopathology including Gleason's score and pathological Group grade. The comparison of two imaging modalities in detecting and staging of primary, Nodal staging and distant metastatic staging was studied. Results: All 25 patients showed 68Ga-PSMA avid disease, whereas 22 were detected by mpMRI. 17/25 were low grade PCa of Gleason's score 3+3 and 3+4. mpMRI was negative in 3 patients who had Gleason's 3+4 disease. The overall sensitivity, specificity, PPV, NPV of 68Ga-PSMA PET/CT were 97.67%, 85.71%, 97.67%, 85.71% and mpMRI were 79.07%, 85.71%, 97.14%, 40.00% respectively for detection of prostatic lesions. 4 patients were positive for seminal vesicle involvement, among which 3 were positive in 68Ga-PSMA PET/CT and 2 were positive in mpMRI. Neurovascular bundle involvement were found in 5 patients by mpMRI, whereas this could not be commented upon on 68Ga-PSMA PET/CT. 68Ga-PSMA PET/CT detected more patients with regional lymph nodal involvement (4/25) as compared to mpMRI (3/25), 1 patient showed invasion of posterior wall of urinary bladder in both 68Ga-PSMA PET/CT and mpMRI. Both 68Ga-PSMA PET/CT and mpMRI detected pelvic skeletal lesions in 2 patients. 2 patients were showing isolated rib and vertebral metastasis which were detected in 68Ga-PSMA PET/CT. Conclusion: 68Ga-PSMA PET/CT has superior sensitivity in detection of intraglandular prostate tumor and lymphnodal metastasis, as compared to mpMRI. It also has an edge over mpMRI in whole body screening for skeletal metastases. Thus, 68Ga-PSMA PET/CT should be considered as a first line investigation, in a suspected case with elevated serum PSA level or biopsy proven case of low and intermediate grade carcinoma prostate. If 68Ga-PSMA PET/CT shows localized disease, mpMRI should be performed to detect the neurovascular bundle involvement and extracapsular extension.


   OP6: Sentinel lymph node imaging and biopsy in early breast cancer: An institutional experience from GCRI for the year 2018–2019 Top


Swati Rachh

Gujarat Cancer and Research Institute, Civil Hospital Campus, Ahmedabad, Gujarat, India.

Aim: Sentinel lymph node imaging and biopsy (SLNB) is the gold standard for management of node negative axilla in early breast cancer (EBC). Objective of present study is to share our experience, see the concordance between radioactive and blue dye technique, to study effect of various factors on success of SLN identification, to analyse factors predicting presence of other positive nodes (other than SLNs) in axilla. Materials and Methods: We analysed our prospectively managed data of SLNB in early breast cancer for the year 2018-2019 (till 31st August 2019). Total 173 SLNB were performed, 122 (70.5%) by dual technique (radioactive + methylene blue dye) and 51 (29.5%) by only blue dye technique (methylene blue dye). We excluded the patients with SLNB only by blue dye technique. SPSS 25 software (descriptive statistics) was utilised for statistical analysis. Results: Median age of patients was 52 years (28–82 years). Overall SLN identification rate was 95.1 % (116/122). SLN after lumpectomy (n=28, success rate=89.3 % (25/28)) did not affect SLN identification (p=0.106). There was no statistically significant difference between radioactive (92.6%) vs blue dye (88.5%) technique to identify SLNs with good concordance in 75.2% (92/122) between two techniques. Partial concordance in 15.6% (19/122) patients and total discordance in 9% (11/122) patients observed between two techniques. SLB identified by only by radioactive technique in 8/11 patients with discordance. Median of total number of sentinel lymph nodes was 4 (1–13). SLNB was positive in 28.7% (35/122) patients. Thirty-six (29.5%) patients underwent axillary lymph node dissection (ALND) after SLNB due to positive SLN (30 patients) or non-identification of SLN (6 patients). In only 33.3% patients who underwent ALND had extra positive nodes in axilla after positive SLN. Presence of 3 or more positive sentinel nodes (100% vs. 20%), positive non blue non-radioactive node (suspicious enlarged node) (66.6% vs. 25%) were associated with high chance of extra positive node in axilla other than positive SLN. No patients with DCIS (n=1), favourable tumor biology (papillary,mucinous,tubular) (n=8) and metaplastic carcinoma (n=2) had positive nodes in SLNB. Conclusion: There is good concordance observed between both radioactive and blue dye technique with discordance in 11 patients. SLNB should be performed even after lumpectomy. Chances of extra positive axillary nodes (other than SLN) are high when 3 or more SLNs are positive or non-blue non-radioactive node is positive. Favourable tumor biology is associated with high chance of negative SLNs.


   OP7: Incidence and distribution of extramedullary disease in patients with multiple myeloma as detected on F-18 FDG positron emission tomography-computed tomography: A single centre longitudinal study of 124 patients Top


Braj Kishore Singh, Kartikey P. Solanki, A. G. Pandit, Anurag Jain

Department of Nuclear Medicine, INHS Asvini, Colaba, Mumbai, Maharashtra, India.

Background and Introduction: Multiple myeloma (MM) is a malignant plasma cell proliferative disorder typically contained within the bone marrow (medullary disease). Infrequently, extramedullary disease (EMD) occurs with the presence of malignant plasma cells outside of the bone marrow within soft tissue, lymph nodes, muscle, skin and other organs (extramedullary myeloma). EMD is more often seen with relapsed refractory disease, and may be associated with decreased overall survival. Objective: The aim of this study was to determine the incidence EMD in MM and sites of its extramedullary dissemination. Methods: 124 diagnosed cases of MM at our institution underwent FDG-PET/CT imaging. For each PET scan, each patient was intravenously administered 8 to 10 mCi (370-555 MBq) of FDG with imaging at 60 minutes post-injection extending from the top of the head to the soles of the feet. EMD identified on PET was confirmed by biopsy or clinical follow-up. The laboratory values most frequently elevated and associated with EMD were examined. A strict definition of EMD was followed which required that to be called EMD, the lesion must not have risen from any bone. Thus, masses arising from the bone with a soft tissue component were not considered extramedullary. Results: Of 124 patients studied, 22 patients (17.7%) had EMD. In 6 of the 22 patients, EMD was present at time of diagnosis of MM. The EMD sites involved included the temporal area (not arising from the skull) soft tissue, muscle, chest wall not attached to bone, abdominal/pelvic masses, kidney, sinus, paraspinal, subcutaneous tissue, mediastinum. The median number of extramedullary sites per patient was 1. Conclusion: The incidence of EMD has increased, probably due to the availability of more sensitive imaging techniques and the prolongation of patients' survival. A whole-body approach of FDG-PET/CT offered the advantage of detecting sites/presence of EMD which was not included in the field-of-view on other imaging modalities.


   OP8: Prognostic significance of pretreatment 68Ga-DOTANOC positron emission tomography/computed tomography in paediatric neuroblastoma Top


Swayamjeet Satapathy, Ashwin Singh Parihar, Rajender Kumar, Harmandeep Singh, Deepak Bansal1, Amita Trehan1, Bhagwant Rai Mittal

Departments of Nuclear Medicine and 1Paediatrics, Post Graduate Institute of Medical Education and Research, Chandigarh, India.

Aim: Neuroblastoma, a neural crest cell derived tumor, is a common malignancy in childhood. It is a heterogeneous disease with several factors known to affect treatment and survival outcomes. Expression of somatostatin receptors (SSTRs) in neuroblastoma allows positron emission tomography/computed tomography (PET/CT) imaging with 68Ga labelled somatostatin analogues and detection of metastatic burden. The present study was conducted to evaluate the prognostic role of 68Ga – DOTANOC PET/CT in paediatric neuroblastoma and compare it with other known risk factors. Materials and Methods: We retrospectively reviewed the records of 165 patients who underwent 68Ga – DOTANOC PET/CT at our centre from January 2011 till January 2019 for neuroblastoma. Of these, 42 children (of age less than 14 years) with histopathologically proven disease, who underwent 68Ga – DOTANOC PET/CT for initial evaluation, prior to any therapeutic intervention, were included in this study. Age, gender, histopathological classification of the tumor, location, dimensions & standardized uptake value (SUVmax) of the primary tumor and site(s) of distant metastasis, if any, were recorded for each patient. The parameters were compared between groups distinguished by survival status. Survival analysis was performed using Kaplan-Meier curve method and Cox Proportional Hazards Model. Results: 42 patients (23 males and 19 females) with median age of 2 years (range 1 – 13 years) were included in the study, with majority (45%) having differentiated disease. 20 patients (48%) died during the follow up period. In comparison with survivors, non-survivors had larger dimensions with lower SUVmax of the primary tumor (median size 7.5 cm versus 11 cm, p=0.025 and 9.2 versus 4.9, p =0.012 respectively) as well as a higher proportion of metastatic disease (41% versus 80%, p=0.011). Tumor size and SUVmax cut-offs of 8.6 cm and 7.1 respectively discriminated between the survivors and non-survivors with sensitivity of 64% and specificity of 75% for each parameter. On survival analysis using Kaplan-Meier curve method and log rank test, patients having localized disease with tumor size <8.6 cm and SUVmax ≥7.1 had significantly longer mean survival. On multivariate analysis, SUVmax of the primary tumor was found to be the only significant risk factor predicting overall survival [hazards ratio 0.86 (95% CI 0.74 – 0.99); p=0.045]. Conclusion: 68Ga – DOTANOC PET/CT assisted in metastatic work up and risk stratification of patients with neuroblastoma, thereby making it a non-invasive and cost-effective biomarker in this setting. It also has therapeutic implications with regard to selection of patients for Peptide Receptor Radionuclide Therapy.


   OP9: Efficacy of indigenous Re-188 microspheres formulation for selective internal radiation therapy in liver tumor and asses response using three phase contrast enhanced computed tomography Top


Swathy Krishnan, Jaya Shukla, Naveen Kalra1, Ajay Duseja2, Bhagwant Rai Mittal

Departments of Nuclear Medicine, 1Radiodiagnosis and 2Hepatology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.

Aim: To evaluate the efficacy of indigenous Re-188 microspheres formulation for selective internal radiation therapy in patients with tumor in the liver and asses response to Re-188 microspheres using three phase CECT. Materials and Methods: Patients with unresectable liver masses treated with Re-188 microspheres for SIRT between August 2015 and July 2019 (n=30) were identified retrospectively. All patients were evaluated for Child Pugh A/B and performance status and studied with angiography and 99mTc MAA scintigraphy to rule out abnormal shunting before administering Re-188 microspheres. Three phase CECT was done for all these patients prior to therapy. 23 patients underwent follow up scan with post therapy three phase CECT at 2-3 months of SIRT. Response was evaluated using modified Response Evaluation Criteria in Solid tumors (mRECIST). Overall survival was estimated by Kaplan-Meier method. Results: A total of 30 patients (Male: Female= 25: 5; median age 58.4 yrs) were included in the study. The cases were of Hepatocellular carcinoma (HCC) (n=28), cholangiocarcinoma (n=1) and neuroendocrine tumor with liver metastases (n=1). The mean dose administered was 90mCi (3330MBq). Most of the patients with HCC were in the BCLC B/C with 1 patient in BCLC D stage of which 13 (43.3%) patients had portal vein thrombosis (PVT) and rest without portal vein thrombosis but had history of treatment done in the form of medical management with Sorafenib, TACE and other procedures. Post therapy patients had mild abdominal discomfort (n=10), abdominal distension (n=2), jaundice (n=1) and vomiting (n=2). None of the patients had any severe side effects. The mean overall survival duration of patients was 9.1±1.8 months. The major dichotomizing subgroups assessed using Kaplan Meier survival analysis were presence of multifocal liver lesions and PVT. 13 (43.3%) patients had multifocal liver lesions while remaining had single liver lesions. It was identified that presence of multifocality had a poorer mean overall survival (7.3 ± 2.3 months) compared to single lesion (10.7±2.4 months). The presence of PVT was found to be associated with poorer survival duration (8.6 ±1.9 months) as against absence of PVT (11.4 ±3.4 months). Post therapy 4 patients showed complete response, 17 partial response, 2 showed disease progression. 7 patients did not undergo any follow up scans. Conclusion: Re-188 microspheres appears to be a effective, safe and promising therapeutic option in these patients with liver tumors. The study showed patients with PVT and multifocal liver lesions have lesser survival than others.


   OP10: Long term outcome of 177Lu-DOTATATE based PRRT in neuroendocrine tumors at tertiary care institute in India Top


Keerti Sitani, Rahul V. Parghane, Sharmila Banerjee, Sandip Basu

Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

Background: The somatostatin receptor (SSTR) is highly expressed on neuroendocrine cells and strongly up-regulated in neuroendocrine tumors (NET). SSTR expression levels are directly correlated to prognosis, response to therapy and survival in NET and therefore SSTR is an attractive target for diagnosis and therapy of metastatic NET. Objectives: The aims of this study were to evaluate the therapeutic response, progression free survival (PFS), overall survival (OS) and clinical toxicity of 177Lu-DOTATATE in the setting of inoperable advanced metastatic NET. Methods: We reviewed the medical records of NET patients, who underwent 177Lu-DOTATATE therapy {13.09-42.36GBq (354-1145 mci) mean-27.37GBq (749.5 mci)} from January 2012 to July 2019 in our institute. Equal 2 or more than 2 cycles of PRRT received patients were included and analyzed retrospectively in this study. The treatment response following PRRT was evaluated under 3 categories: (a) symptomatic (b) biochemical using (serum Chromogranin A and 24 hours Urinary 5HIAA levels) and (c) Imaging response (RECIST1.1 for anatomical imaging and PERCIST 1.1 for molecular imaging). The PFS and OS were also assessed following PRRT. Toxicity assessment was undertaken by NCI-CTCAE scale version 5.0 for hematological and nephro-toxicity. Results: A total of 102 (48 males and 54 females) NET patients (age range: 31-73 yrs; median 52 yrs), who had undergone 177Lu-DOTATATE of at least 2 cycles were identified and selected for the analysis. The follow-up period ranged from 24 months to 84 months (mean: 52 months). The primary sites were {small bowel (n=22), pancreas (n=32), large intestine (n=19), lung (n=6) and unknown primary site (n=23)}. Out of 102 cases, 92 (90%) were responders {CR (n=24, 23.5%), PR (n=26, 25.4%) and SD (n=42, 41.1%)} and 10 (10%) were non responders (PD) on symptomatic scale and on biochemical scale 87 (85.3%) {CR (n=21,20.7%), PR (n=30,35.2%), SD (n=36,35.2%)} responders and remaining 15 (14.7%) were non responders (PD) to PRRT, while on molecular imaging response 90 (89.2%){CR (n=12,11.8%), PR (n=16,15.7%), SD (n=60,60.7%)} were responders and remaining 12 (11.8%) were non responders (PD) to PRRT and on anatomical imaging 89 (87%){CR (n=7, 6.9%), PR (n=8,7.9%), SD (n=74,72.2%) were responders and 13 (13%) were non responders (PD). The mean PFS was 47.1 months (range 12-84 months) and the mean OS was 49.9 months (range 24-84 months). A total of 9 patients (8.8%) expired during this follow-up period with a common factor of widespread metastases especially involving liver was found in 6 (66.66%) out of 9 patients at the initiation of the therapy. During the follow-up period, grade 1 nephro-toxicity was seen in 4 patients (4%) and grade I hemato-toxicity in 1 patient (1%). There was no higher grade nephro- or hematotoxicity. Conclusion: 177Lu-DOTATATE therapy is helpful in disease control and improving symptoms significantly in most of NET patients. The longer PFS and OS is achievable following PRRT with minimal and low-grade toxicity relate to it.


   OP11: Role of FDG positron emission tomography/computed tomography in detecting malignant transformation in patients with neurofibromatosis Top


Suchismita Ghosh, Nilendu Purandare, Venkatesh Rangarajan, Archi Agarwal, Sneha Shah, Ameya Puranik, Sayak Choudhury

Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Mumbai, Maharashtra, India.

Aim: To determine the role of FDG PET/CT in detection of malignant transformation in patients with neurofibromatosis (NF1). Materials and Methods: This is a retrospective study. 16 patients of NF1, over last 15 years, which had presented with new lesions or enlarging lesions and had undergone FDG PET/CT during their treatment were included. PET/CT findings were corroborated against histopathological examination. Sensitivity and positive predictive value of FDG PET for detection of malignant transformation was evaluated. Results: Out of 16 patients, 7 were for initial staging and 9 were for restaging with disease at new sites and distant metastases. Out of 7 patients for initial staging, 6 (85.7%) patients showed lesions that demonstrated a higher degree of FDG uptake (median SUVmax 10.61) compared to rest of the NF1 lesions. These were proven to be MPNST (Malignant Peripheral Nerve Sheath Tumor) on histopathology (true positives) with 2 of them having distant metastases (lungs and thigh), 1 was FDG negative and turned out to be benign neurofibroma (true negative). Out of 9 patients for restaging, 7 (77.7%) patients had disease recurrence at new sites (true positives) out of which 5 also had distant metastases. 2 patients had FDG avid lesion but were benign on biopsy (false positives). Sensitivity of FDG PET/CT to detect malignant transformation was 100% and positive predictive value was 86.7%. Conclusion: FDG PET/CT is a useful non-invasive tool having high sensitivity and positive predictive value to diagnose MPNST with an added advantage of whole body imaging to detect distant metastases which is most commonly to the lungs.


   OP12: Role of F18 FDG positron emission tomography/computed tomography in the detection of recurrence in patients with medullary thyroid carcinoma and raised serum calcitonin levels Top


M. V. Manikandan, Venkatesh Rangarajan, Archi Agrawal

Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Mumbai, Maharashtra, India.

Aim: To evaluate the efficiency of F18 FDG PET/CT in the detection of recurrence in patients with Medullary Thyroid Carcinoma and elevated Serum Calcitonin levels. Materials and Methods: Retrospective study with 85 scans from 79 patients [56 males and 23 females in the age group of 18 to 82 years with median age of 51.2 yrs] who were referred for FDG PET/CT for restaging with elevated serum calcitonin levels were analyzed. Serum calcitonin ranged from 25.5 to 55692 pg/ml. The time of scan from the initial surgery ranges from 2 to 250 months with a median of 28 months. Results: Out of 85 PET/CT scans, 56 were positive and 29 were negative. The recurrent lesions are confirmed by histopathological correlation/imaging and clinical follow-up/further treatment received. The overall sensitivity of FDG PET/CT in identifying the recurrent lesions is 84% with a specificity of 85%. The positive and negative predictive values are 93% and 69% respectively. The sensitivity and specificity are 89% and 63% respectively in patients with calcitonin level more than 500 pg/ml. Conclusion: FDG PET/CT is a sensitive imaging tool in detecting recurrent disease in medullary thyroid carcinoma patients who have elevated calcitonin level. It helps in detecting occult disease and in confirming the nature of suspicious/indeterminate lesions which were identified by other conventional imaging modalities. However, in patients with a lower range of calcitonin levels, the sensitivity is relatively poor which might improve with other new PET tracers like Ga68 DOTA and F18 F-DOPA, which are yet to be studied in detail with a large sample size.


   OP13: Clinical impact of 18 F FET positron emission tomography computed tomography in differentiating suspected recurrence from posttreatment changes in IDH1 mutant and wild type high grade gliomas Top


Indraja D. Dev, Ameya D. Puranik, Nilendu Purandare, Archi Agrawal, Sneha Shah, Venkatesh Rangarajan

Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Mumbai, Maharashtra, India.

Aim: To Assess the Diagnostic Role Of 18 F FET PETCT In Differentiating Suspected Recurrence from Post Treatment Changes in IDH1 Mutant and Wild Type High Grade Gliomas. Methods: We Included 32 IDH1wild Type And 22 IDH Mutant High-Grade Glioma Patients with Suspected Recurrence Who Presented with Equivocal MRI Features. FET PETCT Scan Findings Were Retrospectively Analyzed. T/ W Matter Ratio Was Used as Semiquantitative Parameter. Final Multidisciplinary Joint Clinic Decision (JC)/ Histopathological Findings Wherever Available Were Correlated. Results: Of 32 IDH1 Wild Type Patients, 22 Were Diagnosed as Recurrence On PETCT. On Correlation with JC Decision/ Histopathology, 21 Were Confirmed as Recurrence Which Led to Change in Management of Disease (Only One False Positive Case). Remaining 10 Were Diagnosed as Post Treatment Changes, Out of Them 4 Were Confirmed as Post Treatment Changes and Kept on Observation. In 22 IDH1 Mutant Patients, 11 Were Reported as Recurrence, Of Them 10 Were Confirmed as Recurrence with Change in Management. 10 Were Reported as Post Treatment Changes, 6 Of Which Confirmed with Post Treatment Changes and Kept on Observation With 4 False Negative Cases. ROC Analysis Yielded T/W Ratio Cut-off of 2.24 With Sensitivity Of 85% And Specificity Of 60% For IDH1 Wild Type Patients. For IDH1 Mutant, T/W Ratio Cut-off of 2.8 With Sensitivity Of 66% And Specificity Of 86% With P Value Less Than 0.05. Conclusion: 18F FET PETCT Has High Detection Rates of Early Recurrence in Patient with High Grade Glioma. T/W Ratio on FET PETCT Does Correlate with IDH1 Mutation Status with Resultant Significant Impact On Change In Management Of The Disease.


   OP14: Diagnostic utility of 18F FDG positron emission tomography/computed tomography and derived metabolic parameters in detection of brain SOLs suspicious for primary central nervous system lymphoma Top


Yash Jain, Indraja Dev, Ameya Puranik, Nilendu C. Purandare, Archi Agrawal, Sneha Shah, Venkatesh Rangarajan

Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Mumbai, Maharashtra, India.

Aim: To assess the role of 18 F FDG PET/CT in detection of brain lesions suspicious for primary central nervous system lymphoma. Methods: 45 patients with brain SOLs who underwent pre-treatment 18F FDG PET/CT were retrospectively analysed. Out of these 3 were excluded, as one was detected with systemic lymphoma and two with a lung primary. Of remaining 42 patients, FDG PET/CT findings were diagnostic of PCNSL in 37 patients, while remaining were diagnosed as glioma, metastases and inflammation. SUVmax, Tumor/contralateral white matter ratio (T/w), MTV, TLG were calculated. FDG PET/CT findings were correlated with histopathological diagnosis which was considered as the standard. Results: Out of 37 Patients, diagnosis of PCNSL was confirmed on histopathology in 34 patients and 3 were diagnosed as other primary brain tumors. Overall diagnostic sensitivity was 94%, specificity 50%, positive predictive value 92% and negative predictive value 60%. Roc analysis yielded SUVmax cut off of 14.00 with sensitivity of 89%, specificity of 99%. T/w cut off of 2.2 with sensitivity 94%, specificity 100%. MTV cut off of 25 with sensitivity 74%, specificity 83%. TLG cut off of 103 with sensitivity 91% specificity 83%. Conclusion: In the setting of clinic-radiological suspicion of PCNSL, 18 F FDG PET/CT can be used as sensitive baseline imaging modality and PET/CT derived metabolic parameters have shown significant role in diagnosing Primary CNS lymphoma.


   OP15: Retrospective study of patterns of response to androgen deprivation therapy on 68Ga-PSMA positron emission tomography/computed tomography in prostatic adenocarcinoma patients Top


M. Nihit, A. Agrawal, S. Shah, N. Purandare, A. Puranik, G. Prakash1, G. Bakshi1, M. Pal1, A. Joshi2, K. Prabhash3, V. Noronha3, V. Murthy3, R. Krishnathry3, S. Menon4, V. Rangarajan

Departments of Nuclear Medicine, 1Surgical Oncology, 2Medical Oncology, 3Radiation Oncology and 4Pathology, Tata Memorial Hospital, Mumbai, Maharashtra, India.

Aim: With limited literature on the abilities of 68Ga PSMA PET/CT as a treatment response assessment tool in patients with prostatic adenocarcinoma, we explore the patterns of disease response on this modality with respect to biochemical response based on S.PSA, after medical or surgical androgen deprivation therapy. This may lead to further understanding of the in vivo effect on PSMA expression and disease volume, which may enhance its value in routine clinical practice. Materials and Methods: Whole Body PET/CT scans with 68Ga labelled PSMA-11 ligand, of 60 high risk prostatic adenocarcinoma patients who underwent a baseline scan for staging, followed by a follow up scan after androgen deprivation therapy (ADT), with mean interval of 5.7 months between 2 studies, were included in this retrospective study. Treatment response on PSMA PET/CT based on quantitative volumetric PET parameter PSMA-Tumor Volume (PSMA-TV); in the lines of PERCIST criteria, was compared with biochemical response based on S.PSA levels; using inter-rater agreement using Cohen's kappa coefficient. Lesion-wise response pattern was studied. Results: Overall PET based response with PSMA-TV showed no significant agreement with biochemical response measured with S.PSA (Cohen's kappa value (κ) being 0.07). Overall PET based response with PSMA-TVshowed partial response in 64.2% and stable disease in 16.6 % of the patients with a complete biochemical response. Only 14.2% of patients who had complete biochemical response showed concordant results on PET/CT. 2 cases even showed progressive disease with complete biochemical response. Complete volumetric resolution of metastatic regional/distant lymph nodes in 50 % and skeletal lesions in 66% of the patients with the respective lesions. Primary site disease was the least responsive with 84% cases showing persistent or progressive disease. Conclusion: Discordance between the volumetric response on PET/CT (using PSMA-TV) and biochemical response endorses a possibility of the true objective representation of the post therapy disease burden by 68Ga PSMA PET/CT. Response to ADT differs lesion wise with primary disease showing persistence or progression in a strong majority of patients, whereas metastatic nodal and bony lesions show complete resolution in majority of the patients with the particular lesions respectively. Thus, post therapy PET/CT response may be used as a guide to plan local therapy with curative intent, following ADT. It is particularly useful in cases with low pre-therapy serum PSA levels.


   OP16: Role of baseline 18 F FDG positron emission tomography computed tomography metabolic parameters in prediction of disease free survival in patients with advanced stage Hodgkin's lymphoma Top


Ashish Mohite, Venkatesh Rangarajan, Nilendu Purandare, Archi Agrawal, Sneha Shah, Ameya Puranik, Indraja Dev

Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Mumbai, Maharashtra, India.

Aim: To assess the significance of metabolic tumor parameters on baseline FDG PET/CT in patients with advanced stage Hodgkin's Lymphoma (III/IV). Method: This was retrospective observational study, included 59 patients who underwent baseline 18F-FDG-PET/CT. SUVmax, mean, MTV, TLG (fixed & variable parameters) were calculated using PET VCAR software in GE Healthcare ADW workstation. DFS (disease free survival) was calculated from complete metabolic response obtained on treatment response PET/CT to documented detection of recurrence (on PET/CT or histology). Number, percentage, mean, median, standard deviation, minimum & maximum values will be used for description of the continuous data analysis. Kaplan-Meier method was used to analyze survival outcomes and log rank method for testing the p value. Cox regression model will be performed to determine related factors with DFS. Results: Median survival was 31.5 months (range 13-35 months). Following were the observed median values for: SUVmax -18.3 (p value 0.04), SUVmean -10.18 (p value 0.03), MTV2.5- 569 (p value 0.01), TLG2.5-2541 (p value 0.008), MTV41%-174.6 (0.049), TLG41% is- 1390.6 (p value 0.05). Higher Median values for SUVmax, SUVmean, MTV2.5, TLG2.5, MTV41%, TLG41% are statistically significant for prognosticating advanced stage Hodgkin's Lymphoma. Average disease free survival curve differ significantly for higher cutoff values of all the metabolic parameters used. Conclusion: FDG PET/CT derived metabolic parameters have shown significant role in prognostication of disease free survival in patients with advanced stage Hodgkin's Lymphoma (III/IV).


   OP17: To evaluate the feasibility of 68Ga-pentixafor positron emission tomography based radiotherapy planning in treatment of gliobastoma multiforme patients Top


Samiksha Thakur, Ankit Watts, Abdul Waheed, Renu Madan, Narinder Kumar, Baljinder Singh, B. R. Mittal

PGIMER, Chandigarh, India.

Aim: To evaluate the feasibility of 68Ga-Pentixafor PET based radiotherapy planning in treatment of GBM patients. Materials and Methods: A total of 19 (14M, 5F; mean age 51.6± 14.0 y) patients with histopathological proven Gliobastoma multiforme (GBM) on surgical excised samples and with clinical suspicion of recurrent residual GBM disease during post surgical follow-up were recruited prospectively. Patients underwent ceMRI to know the status of residual/recurrent tumor, additionally 68Ga-Pentixafor PET/CT was done for quantitative imaging of CXCR4 expression & radiation therapy planning in GBM patients. About 110-150 MBq radioactivity of freshly prepared 68Ga-Pentixafor (synthesized by using Scintomics Germany, automated chemistry module, procured under DST- FIST Project Funding) was administered intravenously. Head to abdomen CT (140kv, 200mAs, Pitch 0.625, Slice thickness 2.5mm) followed by PET acquisition 2min/bed position at 1-hour post-injection. The residual tumor was contoured on reconstructed PET/CT images on PET VCAR software on advantage workstation (adw4.7, GE). The tumor was also contoured on the Treatment planning CT linked to the LINAC. Various tumor volumes were computed for radiation therapy planning. Results: MRI demonstrated positive findings for the evidence of recurrent/residual disease in 17/19 patients. In the remaining 2 patients, one was shown to features of gliosis and the one of that of post-surgical hematoma. 18/19 patients had positive 68Ga-Pentixafor PET/CT findings for residual or recurrent disease. The PET findings were in concordance with MRI in 18/19 patients. In the remaining one in which MR demonstrated hematoma, 68Ga –Pentixafor PET findings were positive for the residual/recurrent disease as a focal uptake of the radiotracer was seen in the corresponding. The mean SUVmax values were found to be 3.99± 1.51 (range 1.71-7.37; n=17). Mean Biological tumor volume (BTV's) derived from 68Ga-Pentixafor PET was found to be 66.37 ±48.28 cc & TPCT derived Gross tumor volumes (GTV's) was 99.63±69.83 cc. The mean difference in tumor volume was significant (p < 0.04). These 68Ga-Pentixafor derived BTV depicts the active part of the tumor. Conclusion: 68Ga-Pentixafor showed high focal uptake of the radiotracer in residual/recurrent GBM and the findings of this technique were in agreement with MR findings in 18 (94.0%) of the 19 patients. 68Ga-Pentixafor PET derived biological (by manual method) tumor volumes (BTV) was significantly lower than the MRI derived GTV (gross tumor volume). This information of active tumor volume may be used for the accurate dose escalation to the active disease showing increased tracer uptake for possible better survival outcomes in patients with GBM. A preliminary study is underway to treat GBM patients with escalated radiation dose of additional 10Gy to 68Ga-Pentixafor derived biological tumor volumes and see its prognosis by the department of radiotherapy at our hospital


   Poster Presentation: Oncology Top



   PP1: Correlation of high 18F-flourodeoxyglucose uptake with tumour biology and its relevance on management of early operable breast cancers Top


Piyush Chandra, Senthil Kumar, S. Sridev, Deepti Jain, Satish Nath

MIOT International, Chennai, Tamil Nadu, India.

Aim: Our aim was to assess the correlation of primary breast tumour's FDG uptake and the tumour's biology in early operable stage in order to ascertain its significance on patient management. Materials and Methods: Pre-operative PET/CT of 153 consecutive patients with early operable breast cancers (stage I-IIB) were analysed for differences in maximum standardized uptake value (SUVmax) of the primary tumour between various categorical variable such as T stage categories, histological types, grade, axillary lymph node status, ER/PR status, HER2 overexpression using the nonparametric Wilcoxon rank sum test (when two categories were compared) or the Kruskal-Wallis test (in case of more than two categories). Impact of the tumour biology on diagnostic accuracy of PET/CT for axillary staging was also analysed. Results: The median SUVmax of the primary tumours was significantly higher for T2 compared to T1 tumours (p-0.00), tumours with NOS subtype compared to mucinous/lobular types (p-0.038), grade III vs Grade I/II (p-0.00), ER negative Vs ER positive (p-0.017), PR negative Vs PR positive tumours (p-0.018) and Her2 positive Vs Her2 negative tumours (p -0.007). There was no significant difference in SUVmax values depending upon the age/menopausal status or axillary lymph node status. Accuracy of PET/CT for axillary staging for luminal A (ER/PR+, Her2-), luminal B (ER/PR/Her2+ve), HER2 enriched (ER/PR-ve, Her2+) and TNBC (ER/PR/Her2-ve) tumours was 73%, 85%, 86% and 90% respectively. Conclusion: We found a significant positive correlation between FDG uptake and primary tumor aggressiveness such as size, grade, hormone negativity, HER2 amplification and TNBC status. The implications on clinical practice: 1) Since FDG uptake correlates with biological aggressiveness of the tumour and predicts recurrence, baseline tumour SUV can be explored as a more cost-effective alternative to the highly expensive 21-Gene expression assays in deciding about need for adjuvant chemotherapy for early node negative ER/PR+ tumours. 2) Since the tumour FDG uptake determines the diagnostic accuracy of PET/CT, staging should be avoided in the staging breast cancers in small size (<2 cm), tumours with low-grade histology/Luminal A biology to avoid high false negative findings.


   PP2: Role of dual point 18F flourodeoxyglucose positron emission tomography/computed tomography in the initial staging and management of locally advanced carcinoma cervix Top


Tekchand Kalawat, Muneendra S. Kumar, Ranadheer M. Gupta, A. Y. Lakshmi, T. Kannan, H. Narendra, N. Rukhmangadha, Pranabandhu Das

Department of Nuclear Medicine, Sri Venkateshwara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India.

Aim: To study the utility of dual point 18F FDG PET/CT in management of locally advanced carcinoma cervix. Introduction: Carcinoma cervix is the fourth common cancer diagnosed in female population and is the fourth most common cause of cancer related mortality worldwide. Management of carcinoma cervix is stage based, so an accurate staging of the disease is essential. In this study we evaluated the utility of dual point 18F FDG PET/CT in staging of locally advanced carcinoma cervix. Materials and Methods: We prospectively evaluated 45 patients, histopathologically proved treatment naive locally advanced squamous cell carcinoma cervix with 18F FDG PET/CT. Initial imaging was done 60 minutes post 18F FDG injection and delayed imaging was done after 180 minutes post 18F FDG injection. 18F FDG PET/CT findings were compared with conventional imaging findings. Results: Total of n=45 patients were included in the study. Based on the findings of 18F FDG PET/CT, 60% of the cases were upstaged. In 8.8% of the cases additional image findings were observed in delayed imaging. In 26.6 % of the patients 18F FDG PET/CT localized distant metastases and management plan was changed from curative to palliative intent. Conclusion: 18F FDG PET/CT is highly useful in staging of locally advanced carcinoma cervix and changed the management plan in 60% of the patients. Delayed diuretic phase imaging improved the image quality and interpretation, however no significant information was added to the initial image findings to change the management.


   PP3: Diagnostic accuracy of pre-biopsy 68Ga-PSMA positron emission tomography/computed tomography for detection of prostate carcinoma Top


Piyush Chandra, G. Chandran, J. Sangeetha, R. Shanmugasundaram, K. Karrthik, Satish Nath

MIOT International, Chennai, Tamil Nadu, India.

Aim: Our aim was to evaluate the diagnostic accuracy of pre-biopsy PSMA PET/CT for detection of prostate cancer and to compare its performance with the European randomized study of screening for prostate cancer (ERPSC) risk calculator. Materials and Methods: This was a retrospective analysis of pre-biopsy PSMA PET/CT's of 41 consecutive patients who underwent TRUS guided prostate biopsies for suspected malignancy based on digital rectal examination and raised PSA values (range 0.4- 50 ng/ml). Diagnostic performance of PET/CT and ERPSC risk calculator to detect the likelihood of prostate cancer was evaluated. Statistical significance was derived to assess the difference in variables between benign and malignant group using independent t-test. Results: Out of 41 patients (mean age- 69.1 years, range 52-84) with enlarged prostate (mean volume- 60.7 cc, range 16.5-182) and raised PSA (mean- 13.7 ng/ml, range 0.54-48.2), 36.5% (n=15) patients had biopsy positive for malignancy (mean Gleason's score-8, range 6-10). Mean PSA, prostate to liver maximum standardized uptake value (SUVmax) ratio and primary prostate lesion SUVmax in cases diagnosed as carcinoma prostate was significantly higher compared with benign cases (19.06 ng/ml (p-0.014), 3.09 (p-0.000197), 21.5 (p-0.000046) vs. 10.64 ng/ml, 56.7 cc, 0.66, 4.03 respectively. Mean prostate volume was not significant differently between cancer and benign cases (55.98 cc Vs. 56.7 cc, respectively, p- 0.47). Out of 29 patients, in whom ERPSC risk calculator predicted increased risk of malignancy (threshold 20% risk), only 48% (n=14) patients had biopsy proven malignancy. Keeping primary prostate lesion SUVmax cut off at 6, Sensitivity, Specificity, Positive predictive value and Negative predictive value of PSMA PET/CT for detection of prostate cancer was 93, 92, 86 and 96% respectively with 2 false negatives and 1 false positive result. Using 60% risk cut off, Sensitivity, Specificity, Positive predictive value and Negative predictive value of ERPSC risk calculator for predicting prostate cancer was 43, 88, 67, 74% respectively. Conclusion: Given its very high diagnostic accuracy, PSMA PET/CT can aid clinical decision making in suspected prostate cancer cases by confirming or eliminating the need for biopsies.


   PP4: Comparison of positron emission tomography-computed tomography and computed tomography in detecting locally advanced head and neck squamous cell carcinoma Top


Roma Singh, Geetanjali Arora, Shamim Ahmad Shamim, Chandrasekhar Bal, Atul Sharma, Suman Bhaskar, Ahitagni Biswas, Rajeev Kumar, Aanchal Kakkar, Ranjit Kumar Sahoo, Raja Parmanik, Mukesh Yadav

AIIMS, New Delhi, India.

Aim: Patients with head and neck tumors raise many diagnostic and therapeutic challenges. The conventional imaging modalities such as CT lack the differentiation between residual and post-radiotherapy changes. The present study aims to assess the diagnostic accuracy of PET-CT scan and to compare it with conventional imaging (CT scan), in detecting persistent locally advanced head & neck cancers. Materials and Methods: Ten patients (Age>18 years) with histopathologically proven and locally advanced head and neck malignancy, planned for primary Chemo-Radiotherapy with curative intent, were prospectively enrolled in the study. All patients underwent baseline CT & PET-CT scan. CT and PET-CT scans were repeated at 10-12 weeks post-therapy. RECIST/PERCIST criteria were applied for response evaluation of CT and PET/CT respectively. The scans were compared at baseline as well as post-therapy. Concordance-Discordance was evaluated by estimating kappa values in SPSS v22 software. p<0.05 was considered significant. Results: Ten patients (N=10, Male) with locally advanced head and neck cancer were included in the study. Mean age of the patients was 56.5±10.04 years. These 10 patients comprised of 3 patients of base of tongue cancer, 2 of tonsil cancer, 2 of supraglottic laryngeal cancer and 1 each of pyriform sinus, uvula and vallecula cancer. On baseline CT scan, 4 out of 10 patients were negative. In 1 patient, only primary lesion was detected, in 1 patient only nodal lesion was detected while in 4 patients both primary as well as nodal lesions were detected on CT. In comparison, PET/CT detected primary as well as nodal lesions in 9 patients and in 1 patient only primary lesion was detected. In 4 patients negative on CT, PET/CT was able detect primary as well as nodal lesions in 3 patients and primary lesion in 1 patient. On post-therapy CT scans, 9 patients had partial response and 1 had stable disease. While, 6 patients had complete metabolic response on PET/CT and 3 had partial response. In 1 patient, PET/CT showed progressive disease which had partial response on CT. The kappa value between CT and PET/CT was 0.048 (p=0.62) and 0.096 (p=0.107) at baseline and post-therapy, respectively, indicating discordance between the two modalities. Conclusion: Our results show that PET/CT had higher efficacy in detecting head and neck lesions for primary staging as well as in response evaluation post-therapy. However, study with larger sample size is warranted to establish the findings.


   PP5: A prospective study to compare blue dye and filtered Tc99m sulphur colloid sensitivity and specificity in sentinel lymph node detection in breast carcinoma Top


Yamini Mathur, Anish Bhattacharya, Ishita Laroiya1, Sarika Sharma, Shashank Singh, Bhagwant Rai Mittal

Departments of Nuclear Medicine and 1General Surgery, PGIMER, Chandigarh, India.

Aim: Pilot study performed in our institute to determine the sensitivity and specificity of the blue dye and filtered Tc99m labelled sulphur colloid (Tc99m SC) with intra-operative gamma probe, for detection of sentinel lymph nodes in clinically node negative early stage breast cancer. Materials and Methods: This prospective study comprised 19 patients diagnosed with breast cancer (cT1N0M0-T2N0M0) who were willing to undergo sentinel lymph node biopsy (SLNB), over a duration of 11 months (2018-2019). Patients were given 4 peri-areloar intradermal injections of Tc99m SC. Sequential anterior dynamic images using high resolution low energy collimator were acquired, followed by anterior and anterior oblique static images and SPECT/CT of the affected breast and ipsilateral axilla. Site of sentinel lymph node (SLN) was marked using gamma probe pre-operatively and SLNB was done on the same day using methylene blue and intra-operative gamma probe. Frozen section histopathology of the dissected SLNs (by both the methods) was done. Also, all the patients underwent axillary lymph node dissection (ALND). Final histopathology of SLN detected by blue dye, filtered Tc 99m SC and in ALND were analysed. Sensitivity and specificity of both the methods for SLN detection was compared. Results: SLN data of total 19 female patients of age 53±8 years with cT1N0M0-T2N0M0 was analysed to calculate sensitivity and specificity to identify the SLN. In 79% of patients (n=15) same lymph node was identified by blue dye and Tc 99m SC, 16% (n=3) patients discordance was seen, among which filtered Tc 99m SC identified SLN in all these patients. In 16% (n=3) patients no SLN was identified using blue dye and only in 5% (n=1) patients both filtered sulphur colloid & blue dye couldn't identify any SLN. Sensitivity and specificity of blue dye in detection of SLN was found to be 63% and 91% respectively, while for Tc 99m SC was 88% and 100% respectively. Conclusion: Filtered Tc 99m SC was found to be very specific and sensitive for SLNB using intraoperative gamma probe as compared to blue dye, while preoperative SPECT/CT helped the surgeon to localize the SLN during surgery. However, blue dye has complementary role in identifying the SLN due to ease of visualisation while operating.


   PP6: A prospective study to compare the role of 68Ga-PSMA-11 positron emission tomography/computed tomography and 68Ga-GUL-NOTA-PSMA positron emission tomography/computed tomography in the evaluation of prostate cancer Top


Sneha Prakash, C. S. Bal, Amlesh Seth, Madhavi Tripathi, Sanjana Bhallal, Madhav Prasad Yadav

All India Institute of Medical Sciences, New Delhi, India.

Aim: Detection of recurrent disease and the treatment of metastatic cancer are key issues for prostate cancer patients. Therapy of patients with hormone resistant tumor lesions such as metastatic castration resistant prostate cancer (mCRPC) presents as another major clinical challenge. Due to the over-expression of prostate-specific membrane antigen (PSMA) in prostate cancer, several PSMA-targeting molecules are being tested to both detect as well as treat metastatic castration resistant prostate cancer by targeted radionuclide therapy. 68Ga-PSMA-11 has proven to be highly sensitive and specific for detection of prostate cancer and its metastasis but its drawback is that it cannot bind to therapeutic radiometals, such as 177Lu or 225Ac. A new PSMA ligand GUL-NOTA PSMA can be feasibly linked to both 68Ga as well as 177Lu paving way for future studies into its role in theranostics of prostate cancer. In view of literature showing good results with 68Ga-PSMA-11 PET/CT for evaluation of prostate cancer, we undertook this study to compare both the PSMA ligands for the imaging of prostate cancer, keeping in mind the fact that this would have potential for future theranostics with 177Lu-GUL-NOTA-PSMA therapy. Materials and Methods: 12 patients with histopathologically proven prostate cancer prospectively underwent 68Ga-PSMA-11 PET/CT and 68Ga-GUL-NOTA-PSMA PET/CT within a time window of 30 days. Radiotracer uptake that was visually considered as prostate cancer and its metastases was semi-quantitatively analysed by measuring the maximum standardized uptake values (SUVmax) of the scans acquired 45 mins after injection of 68Ga-PSMA-11 (1.8-2.2 MBq per kg bodyweight) and 68Ga-GUL-NOTA-PSMA (1.8-2.2 MBq per kg bodyweight). In addition, tumor to background ratios were calculated and physiological uptake in parotid gland, bone, liver and kidney was measured.

Results: A total of 51 lesions characteristic for prostate cancer and its metastases were taken using the RECIST method in both 68Ga-PSMA-11 PET/CT and 68Ga-GUL-NOTA-PSMA PET/CT scans. All lesions detected by 68Ga-PSMA-11 PET/CT were also seen by 68Ga-GUL-NOTA-PSMA PET/CT. The SUVmax and the tumor to background ratio were slightly higher in 68Ga-PSMA-11 PET/CT (mean difference of -2.5 and -5 respectively by paired t test). The physiological uptake in salivary glands (p=0.003), kidneys (p=0.002) and liver (p=0.01) was significantly lower in 68Ga-GUL-NOTA-PSMA PET/CT and there was no significant difference in the physiological bone uptake (p=0.09). Conclusion: 68Ga-GUL-NOTA-PSMA PET/CT may detect lesions characteristic for prostate cancer but with slightly lower contrast as compared to 68Ga-PSMA-11 PET/CT. The physiological uptake in salivary glands, kidneys and liver is lower with 68Ga-GUL-NOTA-PSMA signifying less toxicity when used for theranostic purposes.


   PP7: Emerging role of sentinel node identification in early stage of oral cancers: An initial experience Top


S. Abhinav, Sanchay Jain, Ashok Kumar, Pallavi Kaul, Pankaj K. Garg, Manishi L. Narayan

All India Institute of Medical Sciences, Rishikesh, Uttrakhand, India.

Aim: Role of sentinel lymph node (SLN) identification in early stage of oral cancer. Introduction: Oral cavity squamous cell carcinoma (OCSCC) is one of the most common cancers around the globe. In India, the incidence of OCSCC is 16.1% and 4.8% among males and females respectively and overall incidence is up to 10.4%. Currently radionuclide guided SLN (Sentinel Lymph Node) localization is mainly used in management of patients with carcinoma breast and melanoma but the utility of SLN biopsy in head and neck malignancy has not been widely studied in India. Materials and Methods: We have prospectively evaluated 6 consecutive patients with oral cavity cancer, 3/6 patients were in early stage (stage I, II) while the rest 3/6 were in advanced stages of disease (stage III, IV). All patients underwent pre-operative lymphoscintigraphy with SPECT/CT and intraoperative gamma probe to localize the SLN. The identified lymph nodes were examined with frozen section & histopathology for tumour metastasis. In all clinical stages, both these imaging modalities & gamma probe could identify the sentinel lymph nodes. In 4/6 patients including 1/6 (Stage I), 2/6 (Stage II), 1/6 (Stage IVb), no tumour metastases was seen in sentinel nodes on histopathological examination. However, 2/6 patients, (1/6, stage III), 1/6 Stage IVa sentinel nodes were positive for metastases. Results: The prognosis of OSCC depends upon the stage of the disease. Five-year survival decreases from 82% (N0) to 53% as a result of regional nodal involvements, signifying the importance of early detection and treatment of nodal disease in OSCC. Limited neck dissection will have low post-operative morbidity compared to radical neck dissection. In our case series of 6 patients, histopathological examination of 2 patients with advanced OSCC the identified SLN revealed metastasis on histopathological examination, however in patients of early stage OSCC, SLN were negative for metastasis. Identification of metastatic state of SLN helps in avoiding unwanted extensive neck dissection. Conclusion: Correct identification of the SLN using SPECT/CT & intraoperative Gamma Probe can directly influence the extent of neck dissection in oral cavity cancer. Early detection of lymph node metastasis significantly influences the overall management and disease free survival in these groups of patients. Thus, more prospective studies are needed to validate the use of SLNB in routine clinical practice in early stages of OCSCC.


   PP8: Tc-99m labelled amino acid (methionine) SPECT/computed tomography imaging in carcinoma prostate Top


Meena Negi, Vandana Kumar Dhingra, Manishi L. Narayan, Pooja P. Hazari1, Manoj Gupta, Ankur Mittal, Sandip Basu2, Anil K. Mishra1

AIIMS, Rishikesh, Uttarakhand, 1INMAS DRDO, New Delhi, 2Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

Background: Recently Tc-99m labelled methionine has shown promising results with breast and brain tumour imaging. This amino acid is facilitated by upregulation of amino acid transporters and transported in tumour cell by LAT1 transporter. 68Ga-PSMA in PET is an established modality with excellent results for evaluation of prostate cancer. However, in many places the facility may not be immediately available and it may be expensive. Tc-99m labelled methionine could prove to be an effective method for evaluation of tumours using Tc 99m which is readily available at low cost. Aim and Objectives: We explored the possibility of using Tc-99m labelled methionine prepared indigenously for evaluation of prostate cancer. We also studied the radiopharmaceutical biodistribution of Tc-99m methionine. Methodology: Diagnosed prostate cancer patients were enrolled in our study for 99mTc- MDM scintigraphy. For this scintigraphy, 15-20mCi of 99mTc- MDM were injected intravenously to the patient under gamma camera. Immediate flow images, early blood pool image and whole body images were acquired at 10, 60 and 180 minutes. Regional SPECT/CT of pelvis was done at 3 hours. Radiopharmaceutical labelling was assessed qualitatively. Images were correlated with other imaging like bone scan, MRI, ultrasound and biopsy. Results: 15 patients with diagnosed carcinoma prostate were enrolled in the study. 11 patients had metastatic prostate cancer with bone metastasis seen on bone scan and radiology. None of the lesions seen on bone scan showed Tc-99m Methionine uptake. Four patients had locally advanced disease. Of these two patients showed Tc-99m methionine uptake in prostate. Labelling efficiency on visual inspection was found to be satisfactory in all patients. Physiological tracer uptake was seen in kidneys, gall bladder, liver and bowel. Two patients showed mild tracer uptake in bilateral areolar region. Conclusion: This is the first clinical study of Tc-99m labelled methionine in patients with prostate cancer. Our pilot study shows that Tc-99m- methionine does not concentrate in bone metastasis from adenocarcinoma prostate so may not be an appropriate modality for evaluation of the same. Its role in evaluation of local disease can be further assessed.


   PP9: Ex vivo measurement of radioactivity of positron emission tomography/computed tomographyguided biopsy sample to confirm the sampling from viable region of tumor Top


Navjot Kaur, Nivedita Rana, Ankit Watts, Harmandeep Singh, Bhagwant Rai Mittal, Rajender Kumar

Department of Nuclear Medicine, PGIMER, Chandigarh, India.

Aim: Ex-vivo measurement of radioactivity of PET/CT guided biopsy samples to confirm the sampling from viable region of the tumor. Materials and Methods: A total of 50 patients (31 males, 19 females, mean age 51.8±17.8 years) who underwent F-18 FDG PET/CT guided biopsies from October 2018-April 2019 in our department were included in the study. The biopsies were performed using automated ROBIO-EX machine. Biopsy samples were collected in test tube containing formalin and radioactivity was measured using multichannel analyser. Counting factor (counts/mm3.mCi) was calculated where counts represent background corrected net counts, mm3 represent volume of biopsy sample and mCi shows activity at the time of biopsy. SUVmax of the target lesion was also measured on the FDG PET/CT scans. On the basis of final histopathology results, data was categorized into two groups (malignant versus non-malignant). Independent t-test was applied to see differences in mean value of both Counting factor and SUVmax in two groups. Also, Pearson's correlation was calculated between Counting factor and SUVmax of target lesion. Results: Representative sample was retrieved in 49/50 patients while non representative in one. A pathological diagnosis was established in 49 patients while no diagnosis was made in one patient due to non-representative sample. A repeat biopsy confirmed the malignancy in this patient. The mean value of Counting factor in malignant group was significantly higher compared to non-malignant group (21.45 ± 18.05 versus 11.30 ± 8.84, p-value = 0.025). However, the mean SUVmax didn't show statistically significant difference in malignant and non-malignant groups (15.10 ± 9.19 versus 11.55 ± 10.51 respectively, p-value = 0.216). Pearson's correlation coefficient between Counting Factor and SUVmax was 0.457 (p-value = 0.001). The diagnostic accuracy of PET/CT guided biopsies was found to be 98%. Conclusion: The retrieved tissue sample by core biopsies were viable and sufficient to make final diagnosis with high diagnostic accuracy. Ex-vivo measurement of radioactivity (Counting factor) of PET/CT guided biopsy sample can help to predict malignant and non-malignant disease. Contrary to this, quantitative analysis using SUVmax cannot differentiate the same.


   PP10: Efficacy of Tc-99m labelled radiopharmaceuticals in identification of sentinel lymph nodes in carcinoma breast patients: A preliminary analysis from a tertiary care centre Top


Navjot Kaur, Ankur Pruthi, Sunil M. Kumar, Yogendra Rawath, Harvinder Singh

Department of Nuclear Medicine and PET CT, HCMCT Manipal Hospital, New Delhi, India.

Aim: To evaluate the efficacy of Tc-99m labelled radiopharmaceuticals in identification of sentinel lymph nodes (SLNs) in carcinoma breast patients. Materials and Methods: A total of twenty-one female patients (n=21, mean age 58.5±10.5 years) suffering from Carcinoma Breast who underwent sentinel lymph node biopsy at our institute between September 2018 – till August 2019 were included in this study. Tc-99m labelled radiopharmaceuticals such as labelled nanocolloids (3/21), phytate (3/21) and filtered sulphur colloid (16/21) were administered for this purpose. Tc-99m Sulphur colloid was filtered using 0.22 m membrane filter. Preoperative, periareolar injection of radiopharmaceutical ranging between 700-1,000 μCi was administered under sterile conditions and biopsy procedure was performed after 57±10 minutes. During surgery, Intra-operative Gamma probe (Europrobe 3.2) was used to localize SLNs in the ipsilateral axilla, which were identified as lymph node showing counts two times higher than room background. Biopsied sections were then sent for histopathology analysis. Results: Out of 21 patients, SLNs were detected in 20 patients (95.2%). The mean number of sentinel lymph nodes identified per patient were 2.8 ±2.3 (range 0 -12). Mean number of lymph nodes identified with Tc-99m Nanocolloid, Phytate and Filtered Sulphur colloid were 1.7 ± 0.5, 2.3 ± 1.3 and 3 ± 2.5 respectively. Sentinel lymph nodes were found to be positive for malignancy in 19% of cases. In case of Tc-99m labelled nano-colloid and Filtered sulfur colloid, detection efficiency was found to be 100%. However, for Tc-99m labelled phytate, detection efficiency was 66.6%. Conclusion: Tc-99m labelled nanocolloid and filtered sulfur colloid are better than Tc-99m labelled phytate for detection of Sentinel lymph nodes in Carcinoma breast patients. Considering equal sensitivity or detection efficiency of labelled nanocolloids and sulfur colloid, Tc-99m labelled sulfur colloid could be an ideal agent for SLNB due to its cost effectiveness.


   PP11: To evaluate the feasibility of 68Ga-pentixafor positron emission tomography based radiotherapy planning in treatment of gliobastoma multiforme patients Top


Samiksha Thakur, Ankit Watts, Abdul Waheed, Renu Madan, Narinder Kumar, Baljinder Singh, Bhagwant Rai Mittal

Department of Nuclear Medicine, PGIMER, Chandigarh, India.

Aim: To evaluate the feasibility of 68Ga-Pentixafor PET based radiotherapy planning in treatment of GBM patients. Materials and Methods: A total of 19 (14M, 5F; mean age 51.6± 14.0 y) patients with histopathological proven Gliobastoma multiforme (GBM) on surgical excised samples and with clinical suspicion of recurrent residual GBM disease during post surgical follow-up were recruited prospectively. Patients underwent ceMRI to know the status of residual/recurrent tumor, additionally 68Ga-Pentixafor PET/CT was done for quantitative imaging of CXCR4 expression & radiation therapy planning in GBM patients. About 110-150 MBq radioactivity of freshly prepared 68Ga-Pentixafor (synthesized by using Scintomics Germany, automated chemistry module, procured under DST- FIST Project Funding) was administered intravenously. Head to abdomen CT (140kv, 200mAs, Pitch 0.625, Slice thickness 2.5 mm) followed by PET acquisition 2 min/bed position at 1-hour post-injection. The residual tumor was contoured on reconstructed PET/CT images on PET VCAR software on advantage workstation (adw4.7, GE). The tumor was also contoured on the Treatment planning CT linked to the LINAC. Various tumor volumes were computed for radiation therapy planning. Results: MRI demonstrated positive findings for the evidence of recurrent/residual disease in 17/19 patients. In the remaining 2 patients, one was shown to features of gliosis and the one of that of post-surgical hematoma. 18/19 patients had positive 68Ga-Pentixafor PET/CT findings for residual or recurrent disease. The PET findings were in concordance with MRI in 18/19 patients. In the remaining one in which MR demonstrated hematoma, 68Ga –Pentixafor PET findings were positive for the residual/recurrent disease as a focal uptake of the radiotracer was seen in the corresponding. The mean SUVmax values were found to be 3.99± 1.51 (range 1.71-7.37; n=17). Mean Biological tumor volume (BTV's) derived from 68Ga-Pentixafor PET was found to be 66.37 ±48.28 cc & TPCT derived Gross tumor volumes (GTV's) was 99.63±69.83 cc. The mean difference in tumor volume was significant (p < 0.04). These 68Ga-Pentixafor derived BTV depicts the active part of the tumor. Conclusion: 68Ga-Pentixafor showed high focal uptake of the radiotracer in residual/recurrent GBM and the findings of this technique were in agreement with MR findings in 18 (94.0%) of the 19 patients. 68Ga-Pentixafor PET derived biological (by manual method) tumor volumes (BTV) was significantly lower than the MRI derived GTV (gross tumor volume). This information of active tumor volume may be used for the accurate dose escalation to the active disease showing increased tracer uptake for possible better survival outcomes in patients with GBM. A preliminary study is underway to treat GBM patients with escalated radiation dose of additional 10Gy to 68Ga-Pentixafor derived biological tumor volumes & see its prognosis by the department of radiotherapy at our hospital.


   PP12: Prospective evaluation of prostate specific membrane antigen expression in recurrent high grade gliomas using Ga-68 prostate specific membrane antigen positron emission tomography/computed tomography Top


Arunav Kumar, S. T. Arun Raj, Madhavi Tripathi, K. P. Haresh1, Subhash Gupta1, Nishikant Avinash Damle, Manmohan Singh2, Angel Hemrom, K. Sreenivasa Reddy, Madhav Prasad Yadav, Chandra Sekhar Bal

Departments of Nuclear Medicine, 1Radiation Oncology (IRCH) and 2Neurosurgery, All India Institute of Medical Sciences, New Delhi, India.

Aim: High-grade gliomas are aggressive brain tumors and include Grade III and IV of WHO classification. They are associated with a high rate of recurrence after initial resection. Treatment strategies for recurrent high grade tumors are still evolving. Even with these therapies the prognosis is dismal and warrants evaluation of new therapeutic targets and techniques. We evaluated Prostate Specific Membrane Antigen (PSMA) expression in recurrent high grade glioma using Glu-NH-CO-NH-Lys-(Ahx) [Ga-68(HBED-CC)]) (Ga-68 PSMA11) positron emission tomography (PET) for potential theranostics. Patients and Methods: Fourteen patients (M:F=9:5, Age:11-50, median-30 years) with histologically proven high grade gliomas and proven recurrence by magnetic resonance imaging (MRI) underwent Ga-68 PSMA PET/CT. Ga-68 PSMA (3–5 mCi) was injected intravenously and brain PET was acquired 45–60 minutes post-injection (Biograph mCT, Siemens). Visual evaluation was based on intensity of uptake and scored on a scale from 1 to 4, no uptake: score 1, mild uptake less than parotid: score 2, intense uptake equal to parotid: score 3, intense uptake > parotid: score 4. Scans were analyzed semiquantitatively using SUVmax of the target lesion, contralateral hemisphere, centrum semiovale, and parotid and target to contralateral/regional ratios (TCR) were calculated. Correlation of tumor MIB index and SUVmax were calculated using Spearman correlation coefficient. Relationship between mutation status (including IDH, p53 and ATRX) with SUVmax and TCR were also assessed using Mann Whitney U test. Results: 14 patients underwent imaging, 9 had recurrence after initial resection and therapy, while 5 had recurrence after re-resection of tumor [MIB index – median (IQR) -20% (15-25%)]. Twelve out of the fourteen patients had score of 2/3 and two had score of 4 on visual scoring. Lesion SUV max 5.7 (median), range being 2.65-23.92. Median TCR values were 24.8 (19.2-39.4)- contralateral cerebral hemisphere, 47.3 (29.7-75.8)-centrum semiovale and 23.7 (12.9-44.0)-contralateral cerebellum. Tumor to parotid gland SUV max ratios were also calculated with a median value of 0.4 (0.32-1.25). Only two patients had tumour to parotid SUVmax ratio more than 1. There was no significant correlation with tumour MIB index and the uptake values and there was no significant association between the status of mutations and lesion SUV max values and TCR. Conclusion: Ga-68 PSMA 11 PET/CT is a potential theranostic tool in the evaluation of high grade glioma recurrence. High tumor to background ratios suggest its potential application as a guide to plan PSMA targeted therapy using beta and alpha emitters.


   PP13: Clinical impact of 18F-fluorodeoxy glucose positron emission tomography/computed tomography in the management of malignant melanoma Top


Meivel Angamuthu, Shamim Ahmed Shamim, Geetanjali Arora, Shashwat Somani, S. T. Arun Raj, Rakesh Kumar, Madhavi Tripathi, Chandrasekhar Bal

All India Institute of Medical Sciences, New Delhi, India.

Aim: To ascertain the clinical impact of 18F-Fluorodeoxy glucose PET/CT in the management of malignant melanoma in an apex tertiary care hospital. Materials and Methods: Patients with malignant melanoma who underwent 18F-FDG PET/CT between Jan 2017 and August 2019 were included in this retrospective analysis. Patient demographics, clinical indication for PET scan, scan findings such as presence of disease at primary site, metastases and impact on clinical management were analysed. Results: Total of 101 18F-FDG PET/CT studies (in 80 patients) were performed for malignant melanoma during the above mentioned period. Out of which 56 patients had undergone 18F-FDG PET/CT for once and 25 patients underwent FDG PET/CT for twice or more. Patients who underwent for only single scan were included in the study. The number of male and female candidates in the study group were 30 and 26 respectively. The mean age of the patients was 49 years. Among the total of 56 PET scans, 37 studies were performed for staging and 19 were done as a follow up to assess disease status. In the staging group, no significant metabolically active disease could be detected in 7 patients; local disease alone was found in 15, lymph nodes alone in 2, local and lymph nodes in 3 patients and distant metastases in 10 patients. In the follow up group, in 8 patient there were no evidence of disease; local disease was found in one patient, local disease and lymph nodes metastases in one patient and distant metastases in 9 patients. Thus, FDG PET upstaged total of 19 patients (34%) in whom distant metastases was not previously known. Conclusion: We emphasize the value of FDG PET/CT in the management of malignant melanoma management. In our study, more than one-third of patients had change in management after PET/CT scan.


   PP14: Role of 18F-fluorodeoxy glucose positron emission tomography/computed tomography in the follow-up of patients with malignant melanoma postresection of primary Top


Shamim Ahmed Shamim, Meivel Angamuthu, Geetanjali Arora, Shashwat Somani, S. T. Arun Raj, Rakesh Kumar, Madhavi Tripathi, Chandrasekhar Bal

All India Institute of Medical Sciences, New Delhi, India.

Aim: To assess the role of 18F-FDG PET/CT in the follow up patients with malignant melanoma post resection of primary. Materials and Methods: Patients with malignant melanoma who underwent 18F-FDG PET/CT between January 2017 and August 2019 post resection of primary tumor, for atleast twice at a minimum interval of 6 months were included in this retrospective analysis. Patient demographics and scan findings such as presence of residual disease, lymph nodes and metastases were analysed. Results: A total of 17 patients underwent 18F-FDG PET/CT twice or more post resection of primary tumour during the above mentioned period. The number of male and female candidates in the study group were 12 and 5 respectively. The mean age of the patients was 44.5 years. Four patients received chemotherapy, three received radiotherapy, two received chemotherapy and radiotherapy, one patient received immunotherapy, one received chemoradiotherapy and immunotherapy. No metabolically active disease could be detected in 5 patients. Persistent local residual disease was detected in one patient. Stable metastatic disease was found in 3 patients. New metastatic lesions were detected in 5 patients. Resolution of disease was found in 3 patients on follow up. Conclusion: 18F-FDG PET/CT is a valuable tool in the surveillance of malignant melanoma patients. In our study almost 30% of patients were found to have new sites of metastases based on PET scan.


   PP15: Role of 18-FDG positron emission tomography-computed tomography in staging and early treatment response evaluation in patients of soft tissue sarcomas Top


Tejesh Pratap Singh, Sameer Bakhshi, Chetan D. Patel, Anil Kumar Pandey, Atul Batra, Ekta Dhamija, Rakesh Kumar

All India Institute of Medical Sciences, New Delhi, India.

Introduction: Studies have investigated the ability of FDG PET-CT to predict the outcome in patients with soft tissue sarcoma which have shown pre-therapy SUV- max to be of prognostic value. With this information, a prospective clinical study with mid therapy FDG PET-CT was designed to assess whether it added additional prognostic information in addition of pre-therapy and end of treatment FDG PET-CT. Methodology: Eight patients with treatment naïve non-bone, non-rhabdo soft tissue sarcoma were treated with NACT (neoadjuvant chemotherapy). Mean age of the patients was 22.50 +/- 11.13 years. All patients were injected with 8 milli curie of FDG and underwent scan after 1-hour post administration. Whole body images and spots of primary lesion were acquired. Patients underwent a baseline, interim (at the end of 2 cycle) and end of treatment PET. Tumour histopathology, size, grade and FDG uptake (SUVmax-standardized uptake value & MTV- metabolic tumour volume) were recorded. Student t-test was applied to the clinical and imaging data. Results: Of the studied patients, histopathologically, four were diagnosed as synovial sarcoma, two as spindle cell sarcoma and one each as-angiosarcoma and extra-osseous ewings sarcoma. All eight patients underwent base line and interim PET. One patient died before undergoing end of treatment FDG PET and was considered as a non-responder in analysis. Baseline mean SUVmax of non-responders (as defined by end of treatment PET) was 10.4 and baseline mean SUV max for responders was 19.95. Baseline mean MTV among non-responders was 116.27 and among responders was 573. At interim PET percentage change in SUVmax (dSUVmax) among non-responders was an increase of 75.25 (mean), 19.56 (SD). Percentage change in dSUVmax among responders was a decrease of 20.81 (mean), 35.60 (SD), P value =0.130 (equal variance assumed) and 0.297 (equal variance not assumed). Similarly, percentage change in MTV (dMTV) among non-responders showed a increase of 11.75 (mean), 66.34 (SD) and percentage change in dMTV among responders showed an decrease of 69.34 (mean), 20.74 (SD), P value=0.038 (equal variance assumed) and 0.162 (equal variance not assumed). Although there was difference in the value of dSUVmax and dMTV among responders and non-responders, this was not statistically significant. Conclusion: SUVmax and MTV evaluated from interim PET show percentage increase among non-responders, where as in responders both the parameters show percentage decrease. Based on the results, an interim PET-CT might be able to predict the response earlier.


   PP16: Diuretic 68Ga-PSMA positron emission tomography/computed tomography in prostate carcinoma: Comparison with magnetic resonance imaging in locoregional staging Top


Shobhana Raju, Anshul Sharma, Sanjay Kumar, C. S. Bal, Rakesh Kumar

All India Institute of Medical Sciences, New Delhi, India.

Early diagnosis and proper staging of prostate carcinoma (PCa) has got great prognostic significance. MRI is preferred for diagnosis and local staging but is often inadequate for detecting micro metastasis and recurrence. 68Ga-PSMA is excellent in these scenarios, but is limited in local staging by its renal excretion and urinary activity in the bladder.Addition of a post diuretic view can therefore be helpful in reducing the renal excretion of 68Ga-PSMA, thereby reducing the background activity and the bladder activity, improving the target to background ratio and adding to the diagnostic confidence. Aim: To assess the utility of diuretic 68Ga- PSMA PET/CT imaging in the locoregional staging of locally advanced PCa and its comparison with MRI findings. Methodology: 38 biopsy proven PCa patients with MRI pelvis were retrospectively included. Whole body 68Ga-PSMA PET/CT scan was acquired 60 min after IV injection of 2-3 mCi of 68Ga-PSMA; followed a delayed pelvic imaging post- diuretic injection. Quantification using SUVmax and lesion to background ratio was done in pre and post-diuretic images in prostate, bladder, seminal vesicle, lymph nodes (>1 cm) and ureter.

Results: The mean age of the thirty eight patients was 65.76 +/- 7.5 years with a median gleason score of 7.0. Mean PSA value of these patients were 85.31.Primary prostatic lesion was detected in MRI in 36/38 patients (94.7 %) while 68Ga PSMA could detect primary lesion in 30 patients (78.9 %) which improved in post diuretic view by 33 patients (86.9 %). MRI detected seminal vesicle invasion in 15/38 patients (39.5 %) and 68Ga-PSMA detected the same in 20 patients which increased to 23 in post diuretic view, giving an incremental value of 53% over MRI. Lymph nodal lesions were detected by MRI in 12/38 patients (31.6 %). 68Ga-PSMA detected lymph nodal lesions in pre-diuretic view in 16/38 and in post diuretic view in 19/38 patients, giving an incremental value of 58% over MRI. The mean lesion to background ratio in pre and post diuretic views were found to be 28.13 +/- 19.42 and 50.56 +/- 39.86 respectively. The post diuretic view showed statistically significant (p value <0.001) improvement in the lesion to background ratio compared to pre diuretic view, which can quantitively improve the diagnostic accuracy. Conclusion: Ga68-PSMA PET/CT post diuretic view was able to improve the local staging of the PCa compared to whole body Ga68-PSMA PET/CT and almost reaching the accuracy of MRI in primary detection; and was able to add to the already better accuracy of PET/CT in detection of minimal involvement in seminal vesicles and micro-metastases in the lymph nodes.


   PP17: Secondary involvement of extranodal DLBCL as demonstarted by FDG positron emission tomography/computed tomography and its prognosis based upon the sites involved Top


Bela Jain

Department of Nuclear Medicine, SGPGIMS, Lucknow, Uttar Pradesh, India.

Aims: Diffuse large B cell lymphoma is the most common of all Non-Hodgkin's lymphoma (NHL). Median age is about 60 years but can also present in young adults. It is an aggressive tumour which can arise in any part of the body. It usually involves lymph nodes but extranodal involvement is also commonly seen. DLBCL is an aggressive tumor that is fatal without treatment. In this study, extranodal DLBCLs are taken into account for characterising other sites of disease involvement including the lymph nodes and predicting the prognosis using the FDG PET/CT. Materials and Methods: 11 patients, age 22-61, 8 male and 3 female, who presented with swelling or mass symptoms were selected, out of which 6 had gastro-intestinal complaints (distention, vomiting, abdominal pain), 2 had CNS symptoms (headache, vertigo, vomiting), 2 presented with naso-oropharyngeal swelling (non nodal) and the remaining 1 had sternal mass. CT scans of these patients revealed masses of varying sizes in the sites involved. LDH was found to be raised in all patients >200 U/L (mean= 638). Excisional biopsy (in 10 cases) or locoregional lymph node biopsy (in one case) revealed diffuse large B cell lymphoma. IHC was consistent with DLBCL (CD 19, CD 20 positive, Ki 67 index > 70%). FDG PET/CT was conducted in these patients for staging and in 4 patients for treatment response. SUV values were calculated for the primary site and other sites with high SUVs were also noted. Follow up study was conducted in 6 patients after surgical and/or chemotherapy treatment and response to treatment was evaluated. Results: Out of the 6 patients of GIT DLBCL, 6 (50%) had involvement of ileocecal junction (2 had excision before PET/CT), 2 (33%) had duodenal involvement and 1 (17%) involved stomach. Mean SUV of the primary site was 14.6. Other sites that demonstrated increased FDG uptake were abdominal lymph nodes in 4 patients (66%), liver in 2 patients (33%) and 2 involved bones (33%). Interim PET/CT i.e. post 3 chemotherapy, FDG PET/CT was conducted in 4 patients (patient 1, 2, 3, 5 and 6) which showed completed response in patient 6 where SUV of other sites was <5. No response was noted in patient 1 as the SUV values post and pre chemotherapy was similar. Partial response was noted in patients involving abdominal lymph nodes (patients 2,3 and 5). Post 6 cycles of chemotherapy, PET/CT showed complete response in patient 5. This suggests that extensive disease in GIT DLBCL, carries less prognostic value if abdominal lymph nodes aren't involved. Involvement of other viscera by DLBCL with the involvement of lymph nodes is a bad prognostic marker. 2 patients had CNS involvement, out of which one had periventricular and temporal while the other had frontal involvement. FDG PET/CT was conducted prior to lobectomy, biopsy confirmed DLBCL. Patient 7 improved after surgery, whereas in patient 2 where abdominal lymph nodes were involved had to undergo 4 cycles of chemotherapy, for remission. S.PSA level was not raised in patient 8. No follow up PET/CT was done. 2 patients who presented with oropharyngeal swelling, not involving lymph nodes, revealed no other FDG uptake in the body. Surgical excision provided relief in these cases. Irrespective of the high SUV in these patients, prognosis was good. One patient with presented with sternal mass. Although bone involvement in DLBCL is extremely rare, biopsy from axillary lymph node and IHC confirmed DLBCL. FDG PET/CT showed involvement of left pleura and abdominal and thoracic lymph nodes apart from the primary site. Left lobe of lung was collapsed. Patient underwent 3 cycles of chemotherapy and interim PET/CT was suggestive of partial response. Here also, involvement of lymph nodes carried prognostic value as in cases of GIT and CNS DLBCL. Conclusion: The study revealed that extranodal DLBCL can involve other sites as well apart from the primary location. The secondary sites need not be in vicinity to the primary. Gasto-intestinal DLBCL can involve liver, stomach, gonads, bones or even cervical structures like tonsils. Brain lymphomas can involve abdominal structures as well like prostate. Involvement of locoregional/distant lymph nodes is common in DLBCL and carries prognostic value. Involvement of lymph nodes was associated with poor/partial response to chemotherapy. Therefore, disease outcome can be predicted on the basis of FDG PET/CT findings.


   PP18: Role of positron emission tomography with diagnostic computed tomography in diagnosis of renal cell carcinoma: Single centre study Top


Kanishk Markam, Manish Ora, Aftab Hasan Nazar, Ashutosh Parashar, Lokeshwaran Madurai Kalimuthu, Sanjay Gambhir

Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.

Aim: To demonstrate the potential use of fluorine-18 fluoro-2-deoxyglucose positron emission tomography (18F-FDG PET/CT) in diagnosis, staging and surveillance of renal cell carcinoma (RCC). Materials and Methods: Whole-body images (vertex to mid-thigh) were acquired in 3-D mode 40-50 min after intravenous injection of 370MBq of 18F-FDG using a dedicated LSO PET-CT scanner in Siemens healthineers biograph vision PET/CT system. Reconstruction of the acquired data was performed to obtain fused PET-CT images in transaxial, coronal and sagittal views. Results: Among the 44 patients (male-31 & female-13), mean age 22 ±12.761, 12 were pre-operative patients (27%), 27 were post-operative patients (61%) & 5 were recurrent disease patients (11%). Among 12 pre-operative patients, 11 patients (92%) had FDG avid (mean SUVmax -10.29 ±8.527) primary lesion, 3 patients (25%) had FDG avid (mean SUVmax- 4.46) mediastinal lymph nodes (LN), 3 patients (25%) had FDG avid (mean SUVmax- 9.39) abdomino-pelvic & retroperitoneal LN metastases, 4 patients (33.33%) had FDG avid (mean SUVmax 8.42) adrenal metastases, FDG avid extra-abdominal metastasis to lung (mean SUVmax- 4.2) was present in 2 patients (17%), respectively. Among the 27 post-operative patients (61%), 7 patients (26%) had FDG avid (mean SUVmax 2.41) abdomino-pelvic & retroperitoneal LN metastases, 3 patients (11%) had FDG avid (mean SUVmax 6) liver metastases, 2 patients (7%) had FDG avid (mean SUVmax 5.75) adrenal metastases. FDG avid extra-abdominal metastasis to lung (mean SUVmax- 4.3) was present in 6 patients (22%) and bone metastases (mean SUVmax4.03) in 5 patients (19%), respectively. Among the 5 patients (11%) with recurrent disease, all patients had FDG avid primary lesion (mean SUVmax 10.35), 3 patients (60%) abdominal metastases to loco-regional LN (mean SUVmax 15.5) and 2 patients (40%) had liver metastases (mean SUVmax 11.5). Extra-abdominal metastases noted in lung (mean SUVmax 6.3) in 2 patients (40%) & bones (mean SUVmax 11.67) in 2 patients (40%), respectively. Conclusion: Of 44 patients, most commonly involved extra-renal abdominal organ was ipsilateral adrenal gland and most commonly involved extra-abdominal organ was lung along with skeletal metastases. In post-operative patients, recurrence was most commonly located in abdominopelvic and retroperitoneal lymph nodes. These patients undergo chemotherapy most commonly with TKIs. Herein PET/CT plays a major role in staging, restaging and assessing therapy response. Also a post-operative PET/CT assesses the disease burden and helps in prognosticating.


   PP19: Myelodysplastic syndrome: A significant potential myelotoxicity after peptide receptor radionuclide therapy Top


Pankaj Kumar, K. Shreyas, A. Sachin, G. Dinesh, M. Meenu, H. Vishnu, L. Karuna, Vikram R. Lele

Jaslok Hospital and Research Centre, Mumbai, Maharashtra, India.

Aim: Lu-177 DOTATATE Peptide Receptor Radionuclide Therapy (PRRT) is now approved for patient with advanced Gastroenteropancreatic neuroendocrine tumor (GEPNETs) & now becoming established as first & second line therapy. Risk of developing myelodysplastic syndrome (MDS) after PRRT in patient who heavily treated with chemo-radiation needs to be taken into consideration prior to selecting for PRRT. Materials and Methods: A 67 years old female with known well-differentiated NET of rectum (Grade I, Mib1index:1%) with metastatic nodes- underwent surgery followed by 11 cycles chemotherapy with Etoposide & Carboplatin in 2012 & received local radiation to pelvis in 2012 and started on Sandostatin LAR from 2014 to 2017. Ga-68 DOTATATE PET/CT scan revealed somatostatin receptor (SSTR) expressing hepatic and skeletal lesions with peritoneal deposits and nodes (Krenning score 4). Patient received 4 cycles PRRT with 200 mCi Lu-177 DOTATATE from April 2017 to March 2018. On regular follow up - found to have anaemia. Bone marrow aspiration and biopsy and Fluorescence in-situ hybridisation (FISH) test were performed for cytogenetic abnormality. Results: Marked erythroid hyperplasia seen on bone marrow biopsy with low peripheral blood counts. Specimen were positive for deletion of 5q31 & monopsony 7 on FISH test with ASXL1gene found in 11%. Conclusion: Development of rare stochastic event as MDS after PRRT in patient who received multiple Alkylating agent based chemotherapy and radiation - can be minimized by early treatment with PRRT as first line.


   PP20: Correlating quantitative parameters of mpMRI and PSMA uptake in patients with primary prostate malignancy, evaluated using simultaneously acquired 68Ga PSMA positron emission tomography-magnetic resonance imaging Top


Vijay Harish Somasundaram, Rajesh Kannan, Madhavan Kutty, Padma Sundaram, Nirmal Prabhu, P. Shanmugasundaram

Amrita Institute of Medical Sciences and Research Centre, Kochi, Kerala, India.

Aim: To correlate the quantitative parameters of mpMRI with SUV of 68Ga-PSMA uptake among patients with primary prostate malignancy, and possibly identify the threshold value that defines the presence of clinically significant disease. Materials and Methods: This is an ongoing prospective study, wherein patients with biopsy proven or with high clinical suspicion of carcinoma prostate are evaluated with a 68Ga-PSMA PET-MRI study. Whole body as well as regional mpMRI data acquired on a Siemens Biograph mMR 3T system. Quantitative mpMRI parameters such as ADC (apparent diffusion coefficient), Ktrans (influx transfer constant) and Kep (efflux transfer constant) at the suspected tumor site in the prostate were correlated with SUV within the same region of interest. A correlation of these parameters with the histopathological grade of the tumor tissue from the same site is also being made. Results: The initial results reveal a negative correlation between ADC and SUV. A definite threshold for Ktrans and Kep is seen which seem to define cancer differentiation in the prostate. Correlation between these values and the SUV is presently being evaluated. Conclusion: MpMRI and 68Ga PSMA PET are now routinely used tools in the diagnosis and decision making in prostate cancer. This correlative study may help define the tumor characteristics better and eventually help more optimized patient management.


   PP21: Prognostic role of F-18 FDG uptake in brain in comparison to primary tumor in various malignancies at staging Top


Arnaaz Maldar, H. J. Prathap, Shwetal Pawar, Roshni Bhandary

Department of Nuclear Medicine, Seth G.S. Medical College and KEM Hospital, Mumbai, Maharashtra, India.

Aim: To study the prognostic role of brain hypometabolism in patients with concurrent high grade metabolism in various cancers at primary staging and study its correlation to overall survival. Materials and Methods: 33 biopsy proven cancer patients referred for primary staging using F-18 FDG PET/CT who showed high grade metabolism in primary tumor and concurrent hypometabolism in brain on MIP (Maximum Intensity Projection) were selected. Primary brain tumor/ brain metastases/ hyperglycemia /severe anemia /neurodegenerative disorder/ suspected renal failure were major exclusion criteria. Whole body (vertex to mid thigh) F-18 FDG PET/CT imaging was performed 60 min after injection of F-18 FDG at a dose of 3.7 MBq/kg (0.1 mCi/kg) body weight. Metabolic parameters like SUVmax, SUVmean of brain and primary tumor, Whole body MTV and TLG was calculated. Follow up (minimum 3 months period) was done till study completion or death of patient whichever was earlier. Correlation of metabolic parameters with overall Survival (OS) was done. Results: Total 33 patients [M-17, F-16] in whom Mean SUVmax of primary tumor was higher than SUVmax of brain (p =0.0238). Classification (one way ANOVA p=0.0384) was done into three groups A, B and C based on their SUVmax brain values. Group A (SUV brain=<5) showed 100% mortality (6/6). Group B (SUV 5- 7) showed 83.3% mortality (10/12). Group C (SUV >7) had least mortality of 33.33 % (5/15).Significant difference was noted in mortality of patients from these groups (Log Rank Test p <0.05). Overall mortality of study population was 63.63 %. Whole body Metabolic Tumor volume (MTV) and Whole body Total lesional glycolysis (TLG) was found to be highest in group A (brain SUVmax < 5). Mean Overall survival was least in Group A (60.66 ± 24.7 days), intermediate in Group B (76 ± 18.6 days) and maximum in Group C (124.6 ± 48.5 days). Overall survival of study population was 83.19 ± 16 days. Conclusion: In cancer patients for primary staging, concurrent reduced brain FDG uptake is associated with poor Overall survival. Patient group with higher ratio of SUVmax of primary to SUVmax of brain had poorer overall survival. Patients with brain FDG uptake less than SUVmax of 5 showed a higher value of metabolic parameters (MTV and TLG) and poorer prognosis suggesting aggressive nature of tumor affecting brain uptake and overall survival.


   PP22: Prognostic value of 18F-flourodeoxyglucose positron emission tomography/computed tomography in evaluation of resectable lung cancer Top


Shyma Basheer, Naveen Jose Moolan, Parvathy Pavithran, Smitha Moodi, Vijay Harish, Manjith Sarma, S. Padma, P. Shanmugasundaram

Department of Nuclear Medicine, Amrita Institute of Medical Sciences, Kochi, Kerala, India.

Aim: The identification of resectable lung cancer patients with poor prognosis is a priority in clinical oncology because of their high 5-year mortality. This retrospective study analysed the prognostic value of maximal standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) on disease-free survival (DFS) and overall survival (OS) in resectable lung cancer patients. Materials and Methods: A retrospective review of the data at Amrita Institue of Medical Sciences from January 2010 to January 2016 was conducted. Data included demographics, clinical pathological diagnosis, PET-CT imaging and final clinical diagnosis. The impact of SUVmax, MTV or TLG on survival was measured using hazard ratios (HR). Sub-group analyses were performed based on disease stage, pathological classification, surgery, and cut-off values. Results: Of the 32 patients enrolled, 18 patients experienced recurrence of the disease within 2 years. Overall survival after surgical resection of tumors were not affected by MTV and TLG. Patients with even very higher SUV max, MTV and TLG, after surgical resection of tumors had higher 2 year recurrence free survival rates. Conclusion: In patients with resectable lung cancer, 2 year recurrence free survival of patients was not dependent upon values of SUVmax, MTV and TLG. After complete surgical resection, higher FDG uptake measured by F-18 FDG PET/CT might have lost its prognostic value, in patients with early stage of carcinoma lung till stage IIIA.


   PP23: 18F-flourodeoxyglucose positron emission tomography/computed tomography for systemic staging for patients with newly diagnosed breast cancer Top


Shyma Basheer, Naveen Jose Moolan, Parvathy Pavithran, Smitha Moodi, Vijay Harish, Manjit Sarma, S. Padma, P. Shanmugasundaram

Department of Nuclear Medicine, Amrita Institute of Medical Sciences, Kochi, Kerala, India.

Aim: This study assesses 18F–FDG-PET/CT for patientswith newly diagnosed breast cancer. Though FDG PET CT is a well established modality for definitive management of advanced breast cancer, the use of FDG PET CT in early breast cancer remains controversial. Our study is being designed to study the change in the staging of breast cancer due to FDG PET CT and thus change in the management of breast cancer. Materials and Methods: A prospective study of the data at Amrita Institute of Medical Sciences from July 2017 to July 2019 was conducted. Data included demographics, clinical pathological diagnosis, PET-CT imaging and final clinical diagnosis. Results: 8F–FDG-PET/CT demonstrated unsuspected distant metastases in 59 of 150 (39%) patients with newly diagnosed breast cancer, upstaging them to stage IV. Out of 59 patients diagnosed with distant metastasis, 49 patients were above the age of 50 years irrespective of the high risk features. 10 patients were found to have ipsilateral internal mammary lymph nodes which changed the further management of the patients by undergoing adjuvant therapy. But PET CT did not show value in upstaging patients with clinical T1N0 breast cancer. Conclusion: In patients with newly diagnosed breast cancer, 18 FDG PET CT is useful for staging breast cancer, especially in the post menopausal age group. 18F-FDG PET/CT is useful for detecting nodal status and distant metastasis of patients in breast cancer patients by providing incremental information that can influence management and refine prognostic stratification.


   PP24: Role of F-18 FDG positron emission tomography/computed tomography in detecting metastatic disease in initial staging of carcinoma breast patients Top


Murahari Revanth Kumar, Shwetal Pawar, Shilpa Rao, Roshni Bhandary

Seth GSMC and KEM Hospital, Mumbai, Maharashtra, India.

Aim: The aim was to study role of F-18 FDG PET/CT in detection of metastatic disease in initial staging of carcinoma breast especially in loco-regional and locally advanced carcinoma of breast. Methods and Materials: Retrospective observational study was done on 88 breast cancer patients (including 73 cases referred for loco-regional and 15 LABC cases) who underwent F-18 FDG PET/CT. Whole body (vertex to mid thigh) F-18 FDG PET/CT imaging was performed 60 min after injection of F-18 FDG at a dose of 2.2 MBq/Kg body weight. Metabolic parameters like SUVmax, SUVmean of primary tumor, hyper metabolic lymph nodes and distant metastases were calculated. Whole body MTV and TLG was calculated. Results: In 73 cases referred for primary staging of localised disease; most common lymph node involved was ipsilateral axillary in 35 cases (47%) followed by ipsilateral internal mammary lymph nodes in 20 cases (27%). Distant metastases was detected in 32 cases (43%) liver in 5, lungs in 8, bone in 11 and multiple metastasis in 8. Highest mean MTV 57.0 and highest mean TLG 82.6 in stage IV disease. Patients with higher MTV and TLG showed poor prognosis. In 15 cases of LABC; most common lymph node was ipsilateral axillary in 7 cases (46%) followed by ipsilateral subpectoral lymphnodes in 6 cases (40%).Distant metastasis was seen in 3 cases (20%). The detection rate of metastases in LABC and in non- LABC breast cancers showed significant correlation (p value <0.05). Conclusion: There was significant proportion of 35% of non-LABC vs 20% of LABC cases which showed presence of metastases and were upstaged at primary staging using F-18 FDG PET/CT. Higher MTV and TLG values corresponded with greater risk of metastasis and poor prognosis.


   PP25: Incremental role of combining 18F-flourodeoxyglucose positron emission tomography computed tomography with intra-operative sentinel node probing in the management of early breast carcinoma Top


Naveen Moolan, Sundeep Sasi, D. K. Vijayakumar1, Padma Sundaram, P. Shanmugasundaram, Vijay Harish Somasundaram

Departments of Nuclear Medicine and Molecular Imaging and 1Surgical Oncology, School of Medicine, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India.

Aim: Although 18F FDG PET/CT is valuable for detecting distant metastasis, providing prognostic information, identifying recurrence and evaluating response to chemotherapy, the role in evaluating locoregional nodal status for initial staging of breast cancer has not yet been well-defined in clinical practice. Previous publications has compared the efficacy of 18F FDG PET/CT versus sentinel lymph node imaging using SPECT CT for detecting axillary lymph nodal metastases in early breast cancer. In this study, we try to identify the incremental value of combining 18F FDG PET/CT and intra operative sentinel node probing, to correctly identify axillary nodal involvement. Materials and Methods: This is a retrospective and prospective study, wherein recently diagnosed cases of carcinoma breast, with no clinical evidence of nodal or distant metastases were included in the study. All patients underwent a whole body FDG PET CT to stage the disease prior to their surgery. All patients eligible for surgery, received a periareolar administration of 0.5mCi 99mTc sulphur colloid, before the start of their surgery. Intra-operatively, after removal of the primary lesion, a gamma probe was used to identify the ipsilateral axillary node with the highest counts (considered sentinel node). This was excised and frozen section performed to look for evidence of malignant cells. Data from the FDG PET CT study and frozen section results were tabulated and analysed. Results: Among the 31 patients studied so far, 6 of them were identified with FDG avid axillary nodal metastases. However, the intra-operative frozen section of the sentinel nodes (totally 40 nodes in the 31 patients), revealed presence of nodal metastases in 10 patients. Despite having a specificity of 100%, the sensitivity of 18F-FDG PET CT to identify local regional nodal metastases in our patient group was only 43%. Conclusion: The combined application of intra operative gamma probing & sentinel node dissection along with 18F-FDG PET CT, significantly increases the chances of identifying axillary lymph nodal metastases in early breast cancer.


   PP26: Clinical utility of 18F-flourodeoxyglucose positron emission tomography/computed tomography in evaluation of recurrent salivary gland tumors Top


Shamim Ahmed Shamim, Geetanjali Arora, Shashwat Somani, Meivel Angamuthu, S. T. Arun Raj, Madhavi Tripathi, Rakesh Kumar, Nishikant Avinash Damle, Chandrasekhar Bal

AIIMS, New Delhi, India.

Aim: Salivary gland tumors are rare head and neck malignancies, 25% of which are malignant. Role of 18F-FDG PET/CT in recurrent salivary gland tumors has not been adequately studied. Therefore, in the present study we aim to evaluate the diagnostic efficacy of PET/CT in these rare neoplasms. Materials and Methods: 18F-FDG PET/CT scans of 15 consecutive treated cases of salivary gland tumor having suspicion of recurrence were retrospectively analyzed. Scans were reported by two experienced nuclear medicine physicians. Clinical follow up was taken as reference standard. Results: Fifteen patients (Female=10; Male=5) with suspicion of recurrent salivary gland tumor were included the study. Mean age of the patients was 36.4±18.9 years (range: 9-62 years). Of the 15 patients, 10 had mucoepidermoid carcinoma while 5 patients had pleomorphic adenoma. In 11 of the 15 patients (73%) parotid gland was involved, 2 were sub-mandibular and 2 in soft palate/ nasopharyngeal mucosa. Seven out of 15 were reported positive for recurrence on PET/CT scan while 8 were reported to be negative. Six of 7 positive patients had metastasis (Lymph nodes=6; Bone=3; Lung=2; Liver=1). Conclusion: 18F-FDG PET/CT plays a useful role in detection of recurrent salivary gland tumors.


   PP27: Institutional standardisation of dynamic positron emission tomography/computed tomography protocol and its utility for differentiation of benign and malignant lesions Top


R. Hepziba Rajendran

Apollo Hospitals, Chennai, Tamil Nadu, India.

Aim: Dynamic PET/CT is considered to be a cumbersome and time consuming procedure and thus is not done routinely on a daily basis. It becomes tedious for both the scientific personnel to convince and operate as well as the patient to lie down under the scanner for long duration. In our study, we decided to come up with a comfortable and feasible 30 min protocol for Dynamic PET/CT which can be used on a frequent basis. Additionally, we extended our interest to analyse if Dynamic PET/CT can differentiate between benign and malignant lesions based on their rate of glucose utilisation. Materials and Methods: This is an ongoing prospective observational study consisting of 10 patients till date who were established cases of solid tumours referred to Department of Nuclear Medicine and PET/CT, Apollo Hospitals for staging with 18F-FDG PET/CT. Patient was counselled for lying down for at least 30 minutes under the camera. CT of the region of interest was acquired for the purpose of anatomical correlation. 5-6 mCi of F18-FDG was injected under the PHILIPS PET/CT scanner and continuous PET acquisition was done for 30 minutes at a frame rate of 3 minutes/frame. The acquired data was processed in EBW using dynamic lay out. A time activity curve was obtained after drawing appropriate ROIs around the target lesions. The curves of benign and malignant lesions were analysed using slope of curve and SUVmax. Results: 10 cases comprised of 8 cases of carcinoma breast and 2 of lung malignancy. Results were interpreted using 30 minute dynamic protocol. The mean SUVmax of the primary tumours at 30 minutes was 4.6. Time activity curve plotted for SUVmax against time showed a rising pattern with a mean slope of 0.2. The time activity curve of malignant nodes was found similar in rising pattern to the malignant primary lesions with a mean slope of 0.17 whereas the curve for benign nodes was largely a flat line with mean slope of 0.04. Conclusion: Dynamic PET/CT is standardised with a 30 minute protocol at our institute. Using the time activity curves and slope of the curve, dynamic PET/CT might help to raise a possibility whether the lesion is benign or malignant. However, larger sample size and more prospective studies are needed to validate the qualitative assessment of dynamic studies.


   PP28: Impact of CECT protocols in FDG positron emission tomography/computed tomography scans on oncological clinical management Top


Charu Jora

House of Diagnostics, Delhi, India.

Aim: To demonstrate how appropriate usage of CECT protocols in FDG PET/CT scan impacts clinical management of patients in Oncology. Materials and Methods: A retrospective analysis of 2000 FDG PET/CT scans done over a period 9 months was done. All the patients underwent whole body PET/CT scan after 45-90 minutes of injection of 18F FDG. CECT was done using 1.5 ml/kg body wt of Omnipaque in all patients unless contraindicated. A separate dedicated brain series and HRCT chest series was acquired in all patients. Rinse, gargle and puffed cheek head and neck sequence was taken in all oropharyngeal malignancies. A triphasic angiography CT scan was done in all hepato-pancreatic biliary cancers, RCCs and neuroendocrine tumors. A delayed excretory phase was also done in pre-treatment RCCs to calculate Nephrometry score. Oral bolus and distended stomach protocols were done in esophago-gastric malignancies. Injection Lasix was administered in all cases of pelvic malignancies. Rectal contrast was administered in all rectal and left hemicolon malignancies and in locally advanced pelvic malignancies. A full bladder sequence was taken in all cases of carcinoma urinary bladder and to rule out bladder invasion of pelvic neoplasms. Results: Brain series helped pick up early brain metastases in 20 patients. Puffed cheek sequence helped delineate involvement of gingivobuccal sulci and alveolar margins by buccal mucosa and tongue lesions. HRCT helped pick up suspicious lung nodules in high risk patients. Triphasic CT along with serum tumor markers helped in framing non-invasive diagnoses of hepatobilliary malignancies and neuroendocrine tumors which presented as poorly differentiated carcinoma. Rectal contrast in 2 cases of carcinoma cervix demonstrated recto-vaginal fistula. Conclusion: Under usage of CT part of PET/CT imparts incomplete information. Above mentioned protocols increase the scan time by 2-5 minutes but have a significant impact on clinical management of patients. This also justifies the high cost patient pays for this one stop shop modality called PET-CECT scan.


   PP29: Value of 18 F- FDG positron emission tomography/computed tomography in carcinoma of unknown origin Top


Priyanka Verma, Sunita Sonavane, Ramesh V. Asopa

Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

Aim: The aim of this retrospective study is to evaluate to value of 18F-FDG PET/CT in patients with CUP for detecting primary tumor. Materials and Methods: This was a retrospective study including 13 patients (7 males and 6 females, age ranging from 33 to 74 years, mean age 57 years) with carcinoma of unknown origin referred for 18 F- FDG PET/CT for identification of the primary. These patients presented with metastatic lesions that were proven pathologically, and no primary site was detected by previous investigations. The final diagnosis was confirmed either histopathologically or by clinical follow-up. Results: The number of patients with true positive primary tumor sites was 9/13 (69.2%), 2 patients with false positive results (15%), 1 patient with true negative results (17.3%) and 1 patient with false negative results (7%). The most common primary tumor as detected by 18F-FDG PET/CT was lung carcinoma. The sensitivity was 90%, specificity was 66.6% and accuracy was 76.9%. Conclusion: This study showed that whole body 18F-FDG PET/CT is an effective method for detecting the primary tumor in patients with Carcinoma of unknown origin. PET also contributes in staging of the disease and helps patient management.


   PP30: Clinical effectiveness of 177Lu-DOTATATE based peptide receptor radionuclide therapy in 131I-MIBG negative progressive/symptomatic advanced metastatic paraganglioma Top


Rahul Vithalrao Parghane, Sandip Basu, Sharmila Banerjee

Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

Objective: There is no clinical guideline or standardized protocol for the treatment of advanced metastatic paraganglioma (PGL). In the 131I-MIBG concentrating tumors, this is used for targeted treatment, but cannot be employed for 131I-MIBG negative patients. PGLs also express somatostatin receptors that can be utilized for targeted radioisotope therapy. Therefore, aims of this study were to evaluate the efficacy of 177Lu-DOTATATE PRRT in terms of response rate, progression free survival (PFS), overall survival (OS), and clinical toxicity in 131I-MIBG non avid progressive/symptomatic advanced metastatic PGL. Materials and Methods: A total of 1000 patients treated with 177Lu-DOTATATE therapy from January 2010 to July 2019 were reviewed retrospectively; out of this, 10 patients had progressive/symptomatic advanced metastatic PGL (M:F=4:6; age range 33-61 yrs; median-49 yrs; primary site in head and neck (HNPGL)=5 patients (pts), Retroperitoneal PGL=3 pts, Mediastinal PGL=1 pt, Testis PGL= 1 pt; Ki-67 range 1-40%) who were included & retrospectively analyzed in this study. All 10 PGL pts were showed no abnormal MIBG uptake on 131I MIBG scan. The PRRT was considered in 7 pts PGL because of advanced metastatic disease progressive (on other therapies) and in remaining 3 pts for treatment of symptomatic locally advanced disease. The 177Lu-DOTATATE was administered using standard PRRT regimen with mixed amino acid based renal protection and dose of 5.55-7.4GBq (150-200 mCi) per cycle {cumulative dose range: 7.4-37GBq, average 24.42GBq (200-1000 mCi, average 660mCi)} and cycles were repeated at intervals of 12 weeks (range:1-6 cycles, average 4 cycles). The post-PRRT response evaluation included molecular/structural imaging (68Ga-DOTATATE PET/CT), symptomatic and biochemical (serum CgA/ serum and urine metanephrine levels) assessment. The PFS and OS were determined after first cycle of PRRT. The post-PRRT patients were classified as responders (CR, PR and SD) and non-responders (PD) on symptomatic, biochemical, PERCIST and RECIST 1.1 response criteria and also evaluated for clinical toxicity related to PRRT therapy. Results: Of the 10 PGL pts, one patient died before giving PRRT and total 9 pts received PRRT. The PFS ranged from 4 months (mths) to 50 mths with average of 20 mths following first PRRT cycle and OS range from 6 mths to 50 mths with average of 22 mths. Out of 9 pts, 8 pts (89%) were responder to PRRT and 1 patient (11%) was non-responders on clinical symptomatic assessment; 6 pts (66.67%) were responder to PRRT and 3 pts (33.33%) non-responders on biochemical scale; 6 pts (66.67%) were responder to PRRT and 3 pts (33.33%) were non-responders on objective imaging response criteria. All patients had well-tolerated PRRT procedures; there was no major hematological and renal toxicity in any of these pts. Conclusion: The 177Lu-DOTATATE PRRT produces symptomatic improvement and stabilized disease process in significant number of progressive advanced metastatic PGL pts without any major hematological/renal toxicity.


   PP31: To study prostate specific membrane antigen expression using Ga-68 PSMA positron emission tomography in treatment naïve non small cell lung cancer patients and compare it with the conventional F-18 FDG positron emission tomography imaging Top


Sonali Jadhav, Gaurav Malhotra, Ashok Chandak, Sutapa Rakshit, Sunita Sonawane, Unnati Desai1, Ketaki Utpat1, Jyotsna Joshi1, Ramesh V. Asopa, Sharmila Banerjee

Radiation Medicine Centre, Bhabha Atomic Research Centre, 1BYL Nair Ch. Hospital, Mumbai, Maharashtra, India.

Aim: Ga-68 PSMA, that has been conventionally used in imaging of carcinoma prostate, has been found to be non specific with its expression being detected in various carcinomas including breast cancer, high grade gliomas, hepatocellular carcinomas etc. Cohort studies evaluating Prostate Specific Membrane Antigen (PSMA) expression in Non Small Cell Lung Cancer (NSCLC) are lacking. The aims of the present study were to evaluate PSMA expression in NSCLC using Ga-68 PSMA-HBED-CC PET and compare PSMA PET findings with F-18 FDG -PET findings. Materials and Methods: We conducted a prospective observational study from March 2018 till August 2019, in which 30 pathologically proven, treatment naive patients of NSCLC were included. All patients underwent CECT, F-18 FDG PET/CT and Ga-68 PSMA-HBED-CC PET/CT as per the institution protocol with studies being conducted within two weeks of each other. Pregnancy, lactation, those with history of radiation exposure or second malignancy were excluded from the study. Results: A total of 30 patients, 5 females (Age range: 34 to 71 yr; Median age: 63 yr) and 25 males (Age range: 22 to 78 yrs; Median age: 60 yr) were included in the study. 59 lesions including 30 primaries, 19 lymph nodes (LN), 5 bony lesions and 5 other soft tissue metastases were evaluated. Avid FDG uptake was seen in all primaries (100%), 16/19 (84.2%) LN, 5 bone lesions and 3/5 (60%) other soft tissue lesions while PSMA expression was seen in 12/30 (40%) primary lesions, 2/19 (10.5%) LN but not in bone or other soft tissue lesions. The SUVmax of PSMA in 12 concordant primary lesions was low compared to FDG. Conclusion: F-18 FDG PET has better diagnostic yield than Ga-68 PSMA PET in treatment naive patients of NSCLC for detection of primary lesions and metastasis. It shows higher metabolic activity in terms of higher SUVmax of known primary lesions than PSMA scan. PSMA scan may be used as an adjunctive modality to study its expression in primary NSCLC due to its theranostic potential but its role in soft tissue and bone metastasis is not clear from the present study.


   PP32: Role of whole body FDG positron emission tomography/computed tomography to detect metastases in Ewing's sarcoma family of tumors at baseline staging Top


Sreya Ghosh, Nilendu Purandare, Sneha Shah, Archi Agarwal, Ameya Puranik, Venkatesh Rangarajan

Department of Nuclear Medicine, Tata Memorial Hospital, Mumbai, Maharashtra, India.

Aim: To evaluate the role of baseline 18 F FDG PET/CT in detection of metastases in Ewing's sarcoma family of tumors. Methods: This retrospective study included biopsy proven 100 cases of EWSFT (26 cases of chest wall PNET, 4 cases of extraosseous PNET, 70 axial and appendicular skeletal PNET) who were referred for a staging PET/CT. Incidence and location of metastatic disease was calculated. PET/CT findings were confirmed by pathological findings. Tumor board decision/ imaging follow up of at least 6 months were used for validation when pathology was unavailable. Results: 100 patients (73 males, 27 females with an age range of 2-32 years) were included for analysis. 36 patients were diagnosed with metastatic disease. 46.8% (22/47) patients of extremity skeletal primary tumor showed metastatic disease with lung and bones being the commonest sites and liver, soft tissue deposit, nodes being the other sites of involvement. 11.5% (3/26) patients of chest wall primary tumor showed metastases disease to the marrow.42.8% (9/21) patients of PNET of the axial skeleton. Showed metastatic disease to the lungs, bones and nodes).Out of 4 extraosseous PNET, 2 were soft tissues of the chest wall, one in presacral region and one in nasal cavity. Among these, 2 (50%) patients were diagnosed with metastases (lung, bone, soft tissue deposits). Conclusion: Baseline 18 F FDG PET/CT can detect metastatic disease in a significant proportion of patients of EWSFT.PNET of the axial and appendicular skeleton are more likely to metastatize compared to tumors arising from the chest wall. Overall, lung is the most frequent site for metastases, though for chest wall PNET, marrow metastases is most prevalent.


   PP33: Role of 18 F FDG positron emission tomography/computed tomography in recurrent carcinoma gall bladder Top


Anjali Prakash, Akshay S. Bedmutha, Archi Agrawal, Nilendu C. Purandare, Sneha Shah, Ameya D. Puranik, V. Rangarajan

Tata Memorial Hospital, Mumbai, Maharashtra, India.

Aim: To determine the effectiveness of 18 F FDG PET/CT in treated patients of adenocarcinoma gallbladder with clinical, biochemical or radiological suspicion of disease recurrence. Materials and Methods: A total of 40 patients (14 males, 26 females; Median age: 54 years) of treated adenocarcinoma gall bladder with suspected recurrence underwent FDG PET/CT. All the patients had been treated previously with surgery with or without neoadjuvant or adjuvant chemo-radiation, and later presented with clinical or biochemical (rise in S.CEA/S.CA19-9) or radiological recurrence. The PET/CT findings were grouped as loco-regional disease, metastatic abdominal disease and extra-abdominal disease. Results of PET/CT were validated by histo-pathological evaluation or on subsequent close follow-up or based on response to treatment. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Results: Out of 40 FDG PET/CT scans done for suspected recurrence, 33 (82%) were positive and 7 (18%) were negative for recurrence. Of 33 positive PET/CT scans, all patients were proven to harbor recurrence based on histopathological correlation or response to treatment. Among 7 patients with negative PET/CT scans, 3 patients were found to be disease-free on subsequent follow up. However, remaining 4 patients demonstrated continuous rising trend of tumor markers. 3 out of these, who were PET/CT negative during restaging, were eventually diagnosed with morphological peritoneal disease after 3 months on CT. In 1 patient peritoneal disease was diagnosed with follow up PET/CT after 6 months, while the remaining 1 patient developed GB fossa recurrence after 3 months. FDG PET/CT showed a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 89%, 100%, 100%, 43% and 90% respectively, for detecting recurrence in cases of adenocarcinoma gall bladder. Conclusion: In a clinical setting of suspected recurrence of adenocarcinoma gall bladder, 18 F FDG PET/CT can detect recurrence with high sensitivity, specificity, PPV and accuracy. However, negative PET/CT results should be closely followed-up due to high propensity of eventual detection of peritoneal disease.

[TAG:2]PP34: Clinical impact of 68Ga DOTA positron emission tomography computed tomography versus combined Ga68 and 18F-flourodeoxyglucose positron emission tomography/computed tomography on treatment management for patients with Grade II neuroendocrine tumor[/TAG:2]

Shubham Kale, Ameya Puranik, Archi Agarwal, Sneha Shah, Nilendu Purandare, Venkatesh Rangarajan

Tata Memorial Hospital, Mumbai, Maharashtra, India

Aim: To assess the impact of 68Ga DOTA PET CT and 18F-FDG PET/CT modality in management of patients with Grade II neuroendocrine tumor. Materials and Methods: 43 Grade II neuroendocrine tumor patients underwent Ga68 DOTA and F18 FDG PET/CT imaging. 45 mins static whole body scans were acquired. Krennings score and SUVmax were used as semi quantitative parameters. Results: Of 43 histopathologically proven grade II NET, 39 out of the 43 cases were positive for 68Ga imaging (91%) and 24 out of the 43 cases were positive for combined Ga68 and 18F-FDG PET/CT (56%). On subdivision of Mib index,



Conclusion: From above study it can be concluded that, there is a moderate impact of FDG in NET patients with Mib index greater than 10 showing increased GLUT expressing lesions which has influenced the clinical management.


   PP35: Detection of macroscopic disease recurrence in curatively treated nonmetastatic colorectal carcinoma when FDG positron emission tomography-computed tomography is negative in a scenario of rising CEA Top


Arvind Suresh, Venkatesh Rangarajan, Nilendu Purandare, Archi Agrawal, Sneha Shah, Ameya Puranik

Tata Memorial Hospital, Mumbai, Maharashtra, India.

Aim: To identify the detection rate of macroscopic disease recurrence when FDG PET-CT is negative in curatively treated non-metastatic colorectal carcinomas in a scenario of rising CEA. Materials and Methods: A retrospective audit of 49 patients (39 men and 10 women, ages 48.8 +/- 22.8 years) which fit the criteria was done, with site of tumour (colon vs rectum), baseline CEA levels, surgery done, surgical staging, use of adjuvant/neo-adjuvant chemo/radiotherapy, interval until biochemical relapse and the subsequent negative PET-CT. The negativity of the PET-CT is confirmed with another diagnostic modality within the next 6 months. Interval until the CEA level which reveals disease in a subsequent diagnostic modality is also noted. The data is analysed to provide the detection rate of macroscopic disease in these patients. Results: 16/49 patients were stage 3; 15/49 were stage 2, 4/49 were stage 4a and 3 were stage 1 at the time of diagnosis. 29/49 had a subsequent diagnostic investigation within the next 6 months, of which 8/29 revealed macroscopic disease, which were detected by 3 MRIs, 2 PET-CTs and 2 CECTs and 1 restaging laparoscopy. Median CEA level in these patients was 10.35 ng/ml. The true negative cases (21/49) had a median CEA level of 8.64 ng/ml (Range 1.85-22.4 ng/ml). 4/29 of those declared true negative had recurrences at a median interval of 16 months from the index PET/CT with a median CEA level of 22.05 ng/ml (5.12-31.32). 20/49 had subsequent diagnostic investigations done at 7 months and beyond. 6 out of these patients were found to have recurrence after a median interval of 11 months from the index PET/CT (Range 8-23 months), with median CEA level being 32.66 ng/ml at the time of detection (Range: 5.12-332.69 ng/ml). Conclusion: When FDG PET/CT was negative, almost 81% of treated patients had no demonstrable macroscopic disease for a median time period of 16 months when CEA levels were 8.64 ng/ml or less. However, patients with CEA levels of 10.35 ng/ml and above were found to have macroscopic remnant disease detection rate of 27.5% within 6 months by other modalities. This is a limited dataset, and further analysis is needed.


   Oral Presentation: Cardiology Top



   OP1: To assess the feasibility of flourine-18 fluoro L-dihydroxyphenylalanine positron emission tomography-computed tomography for evaluation of cardiac sympathetic innervation in heart failure Top


T. Thayumanavan, Chetan Patel, Chandrasekhar Bal, Sandeep Seth1, Ambuj Roy1, Anil Kumar Pandey, Rajeev Kumar, Praveen Kumar, Anshul Sharma, Meivel Angamuthu, Vivek Baghel

Departments of Nuclear Medicine and 1Cardiology, All India Institute of Medical Sciences, New Delhi, India.

Aim: In this pilot study we tried to ascertain the feasibility of F-18 FDOPA in the evaluation of cardiac sympathetic innervation in heart failure (HF) patients. Method: Six patients with clinical diagnosis of heart failure (NYHA class II–III) underwent F-18 FDOPA study.The global and regional myocardial to mediastinal ratio (MMR) derived from F-18 FDOPA study on patient group was compared with the nineteen age matched controls who had undergone 18F- FDOPA PET-CT for indications other than HF and had no history of coronary artery disease or coronary risk factors. Results: In the controls, the regional MMR for septum was 1.94 ± 0.15, lateral wall was 1.70 ± 0.14, anterior wall was 1.83 ± 0.14, inferior wall was 1.95 ± 0.13 and apex was 1.73 ± 0.13. In patient group, the regional MMR for septum was 1.34 ± 0.33, lateral wall was 1.34 ± 0.47, anterior wall was 1.21 ± 0.22, inferior wall was 1.32 ± 0.32 and apex was 1.16 ± 0.19 which were reduced as compared to the controls and it was statistically significant for all the walls (p< 0.05). Also, the global MMR of the patient group was reduced as compared to control group (1.49 ±0.36 vs 2.02 ±0.14; p< 0.05). Conclusion: F18 - FDOPA can be used in the evaluation of cardiac sympathetic innervation in HF patients. The results of this study needs to be validated on a larger patient population.


   Poster Presentation: Cardiology Top



   PP1: Role of FDG positron emission tomography in cardiac sarcoidosis – Our experience Top


Julie Hephzibah, David Mathew, Nylla Shanthly, Regi Oommen

Department of Nuclear Medicine, Christian Medical College, Vellore, Tamil Nadu, India.

Aim: To assess the role of FDG cardiac PET in the evaluation of cardiac sarcoidosis. Introduction: Sarcoidosis is a heterogeneous disorder of unknown etiology whose characteristic lesions are noncaseating granulomata. Cardiac sarcoidosis (CS) may involve any part of the heart. The key clinical manifestations of CS are conduction system disease, tachyarrhythmias, cardiomyopathy, heart failure and rarely coronary artery disease. Materials and Methods: Twenty six consecutive cardiac FDG-PET/CT studies performed on subjects suspected of having CS were retrospectively analysed. Patient Preparation: Day 1: For myocardial perfusion study: Nil per oral 4 hours prior to study. Day 2: For F-18 FDG PET study: Fasting: 12-16 hours. Diet: High fat (>35 g) and low carbohydrate (<3 g) diet, 12-16 hours before study. For patients with diabetes: Same diet as non-diabetics. Type 1 DM: Insulin will be avoided on the day of the study. Type 2 DM: No oral hypoglycaemic agents /insulin while fasting or on the morning of the test. Imaging Protocol: Myocardial Perfusion Imaging. At 45 minutes post intravenous (IV) injection of 99mTc MIBI 8mCi on Day 1, imaging was initiated with Gamma camera. 18F-FDG Imaging: At 90 minutes post- IV injection of F-18-FDG 10–12mCi, imaging was initiated with Siemens BIOGRAPH -6 (LSO-crystal /6-slice) PET-CT scanner. CT images were obtained of thorax. PET images were obtained from same region. Using CT scans for attenuation correction and localization, images were reconstructed. Results: A total of 26 patients were evaluated, 17 males and 8 females, age ranged from 23-66 years. Predominant clinical presentation was palpitations, ventricular arrhythmia apart from dyspnoea on exertion and syncope. All patients underwent FDG PET study, 13 underwent simultaneous cardiac magnetic resonance imaging (CMR). Positive FDG Study: 13/26 (50%) showed pathological FDG uptake in LV wall. CMR was done for 6/13, 5/6 was positive for CS, 1/6 negative. 5/13 had both thoracic and CS, 4/5 biopsy of node was done which showed granulomatous lesion. One EMB was done which was negative. Follow up FDG PET 6 months after treatment done in 5/13 all 5 showed regression of disease. Negative FDG PET: 13/26 (50%), 7/13 underwent CMR of which 2/7 showed CS (3-DCMY, 2 normal). One patient was found to have thoracic sarcoidosis proved on node biopsy. Conclusion: FDG PET combined with CMR is a robust functional imaging modality in evaluation of cardiac sarcoidosis and should be included as a part of imaging armamentarium in evaluation of symptomatic patients.


   PP2: Comparison of positional artefacts in myocardial perfusion imaging in supine and semireclining position using dedicated D-SPECT cardiac camera and validation using computed tomography based attenuation correction Top


Sejal Chopra, Shashank Shekhar Singh, Ashwani Sood, Madan Parmar, Shelvin Kumar Vadi, Ashwin Singh Parihar, Bhagwant Rai Mittal

Department of Nuclear Medicine, Postgraduate Institute of Medical Education and Reserach, Chandigarh, India.

Aim: The aim of the study is to evaluate the differences in patterns, extent and distribution of attenuation artefacts in supine and semi-reclining positions on CZT based dedicated cardiac camera and their relation with gender, body mass index (BMI) and type of stress administered in SPECT MPI studies. Materials and Methods: We prospectively analysed 150 patients acquired in supine (S) and Semi-reclining (SR) positions on CZT based cardiac camera (D-SPECT, Spectrum Dynamics). An additional CT scan of 50 patients was acquired on conventional SPECT/CT (Brightveiw XCT, Philips) to generate attenuation corrected images. The images were analysed for severity and extent of defect based on hypoperfusion of myocardial segment, independently by two Nuclear Medicine Physicians using 17 segment model. All the defects present in only one position or showing change in severity within two positions were considered as positional artefacts and were validated using CT AC supine image. Results: In overall analysis, the number of positional artefacts observed were more in semi-reclining position involving apex (24% in SR vs. 16% in S; p = 0.045), apical inferior & septal and mid & basal inferolateral segments as compared to supine position where anterior and anterolateral wall were affected. During subgroup analysis, female patients (11/17 segments) showed more positional artefacts as compared to the male patients (7/17 segments). In females, anterior wall (11% in SR vs. 53% in S; p = 0.005) was more prone to attenuation artefacts in supine position as compared to inferior (60% in SR vs. 35% in S; p = 0.016) and lateral wall in semi-reclining position. However, in males, no such trend was observed. The apex and apical anterior segments showed positional artefacts in semi-reclining position whereas in supine position they were more commonly observed in mid inferior and basal anterior segments. A peculiar apico inferior attenuation artefact having was more commonly seen in semi-reclining position and more persistent in male population, higher BMI groups or who had undergone treadmill stress. The occurrence of positional artefacts increased in patients who underwent adenosine stress and higher BMI groups including anterior, inferior and lateral wall in both the positions. Most of the above stated positional artefacts were corrected on AC supine images. Conclusion: The incidence of positional artefacts was more in female patients, higher BMI groups and adenosine stress subsets. Hence images should be cautiously interpreted in both supine and semi-reclining positions to identify and differentiate positional artefacts from true perfusion defects.


   PP3: Effect of additional dietary intervention in reducing interfering infra-cardiac activity in patients undergoing Tc99m-MIBI myocardial perfusion SPECT Top


Shashwat Somani, Priyanka Gupta, Meivel Angamuthu, Vivek Baghel, Konudala Sreenivasa Reddy, K. Lavanya, Anil Kumar Pandey, Chetan D. Patel

Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India.

Aim: The purpose of our study was to determine whether use of additional dietary intervention (tea/carbonated drink with fatty meal) during rest gated Tc99m-MIBI MPS would help in reducing the infra-cardiac activity and thereby improving the image quality and interpretation of the images. Methods and Results: Ninety patients undergoing 1 day stress-rest protocol Tc-99m MIBI MPS were prospectively enrolled in this study. After the radiotracer injection at rest, patients were randomly divided into three groups (30 each). Group 1 patients were advised to have a fatty meal, group 2 and group 3 were advised to have tea and carbonated drink respectively along with the fatty meal. Rest images were acquired between 45-60 minutes post-injection. Images were visually analyzed by two blinded nuclear medicine physicians for the presence or absence of infra-cardiac activity and graded as Grade 0 (No infra-cardiac activity in the vicinity of the myocardium), Grade 1 (Presence of infra-cardiac activity in the vicinity of the myocardium but is not affecting the interpretation.) and Grade 2 (Presence of infra-cardiac activity in the vicinity of the myocardium, affecting the interpretation, resulting in repeat/delayed acquisition.). Results: In Group 1 patients, 31% patients were grade 0, 37.9% grade 1 and 31.0% grade 2. For Group 2 (tea) patients, 70% patients were grade 0, 13.3% grade 1 and 16.7% grade 2. For Group 3 (carbonated drink) patients, 83.3% patients were grade 0, 3.3% grade 1 and 13.3% grade 2. There was a statistically significant difference between Group 2 and Group 3 patients as compared to the Group 1 (p=0.001). However, there was no significant difference between Group 2 and Group 3 (p=0.323). Conclusion: Tea or carbonated drink significantly reduce the infra-cardiac activity in Tc99m MIBI MPS when images are acquired within 45-60 minutes post radiotracer administration.


   PP4: To study the effect of different reconstruction algorithms on cardiac positron emission tomography/computed tomography image quality Top


Kamalpreet Kaur, Ankit Watts, Nivedita Rana, Rajender Kumar, Bhagwant Rai Mittal

Department of Nuclear Medicine, PGIMER, Chandigarh, India.

Aim: To study the effect of different reconstruction algorithms on cardiac PET/CT image quality. Materials and Methods: Sixteen patients referred for routine for myocardial PET imaging were prospectively included in the study. Both 13N-NH3& 18F-FDG imaging was performed as per routinely followed protocol on PET/CT (GE DISCOVERY 710). Image data was reconstructed with company provided reconstruction setting as: incorporation of time-of-flight (TOF), point spread function (PSF), z-axis filter-standard, matrix size: 128x128 matrix and iterative reconstruction with Butterworth filter smoothing filter setting of critical frequency 15 and order 5. Data of first patient was retrospectively reconstructed using both filters (Butterworth & Hanning) & subjected to variable settings (critical frequency 6-20). Sets of best three images were selected for further analysis on rest of the patients. Further the effect of incorporation of TOF & variation of matrix were also studied on the image quality. A four point scoring pattern was followed to qualitatively score the image quality. Quantitative analysis was done by comparing the mean scores of 17-segment polar plot of reference & new set of images. Results: Three best sets of images derived from first patient with butterworth filter were with critical frequency 16, 18, 20 & with hanning was 6, 8 & 10. Upon further analysis on 15 patients, butterworth filter with critical frequency of 16 obtained maximum mean scores for both 18F-FDG (3.80±0.77) & 13N-NH3(3.93±0.50). With hanning filter settings best mean scores were at 6 critical frequency for both 18F-FDG (3.67±0.62) & 13N-NH3(3.67±0.52). Upon applying student t-test the difference was found to be statistically significant with other cut-off values. Incorporation of TOF information in the image resulted in improvement of image quality in both 18F-FDG (3.93±0.50) & 13N-NH3(3.80±0.77) was compared to NON-TOF (18F-FDG -3.67±0.52 & 13N-NH3-3.40±0.63). While increasing in matrix size resulted in deterioration of the image with 128x128 obtained the best mean scores of 3.80±0.56 as compared to 3.53±0.52 & 2.73±0.80 for 192x192 & 256x256 respectively. Upon quantitative analysis of Mean scores with of 17-segmeant polar plots no significant difference was found in the quantitative assessment of polar plots of both 13N-NH3 & 18F-FDG when increasing the Butterworth critical frequency to 18 as compared to standard BW 15. While significant difference in over estimation of the defect was seen when applying hanning filter as compared to standard protocol. Conclusion: The mean scores of Butterworth filter were found to be higher than that of Hanning filter depicting superiority of Butterworth filter over Hanning filter with later overestimating the defects. Best contrast of defect and viable/normal perfused myocardium was found at lower frequencies in both the filters. Processing with Butterworth filter can reproduce same image quality and delineation of defects from conventionally followed cut-off frequency of 15 up to 18. Introduction of TOF into the myocardium imaging yielded in sharper images as compared to NON-TOF images. Higher matrix size (192x192 & 256x256) resulted in deterioration of image quality as compared to conventionally followed 128x128 matrix size.


   PP5: Evaluation of multivessel coronary artery disease using cadmium zinc telluride cardiac gamma camera Top


N. Varsha, H. V. Sunil

Narayana Hrudayalaya, Bengaluru, Karnataka, India.

Purpose: The purpose of this study is to evaluate the performance Cadmium Zinc Telluride (CZT) gamma camera in detecting multivessel coronary artery disease. Materials and Methods: One hundred and eighty two patients who had been referred to our department for stress MPI were enrolled into the study. All the patients underwent one day-stress-rest MPI protocol using appropriate physical or pharmacological stress and underwent coronary angiogram within three months. The imaging was done in supine position with CZT cardiac gamma camera. The images were analysed visually by the nuclear medicine physician, blinded to the angiographic findings. The images were analysed semi quantitatively using SSS, SRS and SDS scores. Results: The diagnostic accuracy of CZT gamma camera in detecting single vessel disease (AUC 0.944, p <0.0001), double vessel disease (AUC 0.944, p <0.0001) and triple vessel disease (AUC 0.949, p <0.0001) was excellent. It showed excellent accuracy in detecting abnormality irrespective of coronary artery involved with AUC 0.894 for left anterior descending artery (P <0.0001), AUC 0.903 for left circumflex artery (P <0.0001) and AUC 0.843 for right coronary artery (P <0.0001). Conclusion: SPECT MPI with cardiac specific CZT gamma camera has showed good diagnostic accuracy in detection of multivessel CAD. This is a reliable non invasive test in the diagnosis of multivessel CAD.


   PP6: Comparison of left ventricular ejection fraction estimated using 99mTc-sestamibi quantitative gated SPECT with echocardiography indexed to body habitus Top


Ashok Kumar, Tejasvini, Sanchay Jain, Vandana K. Dhingra, Bhanu Duggal1, Manishi L. Narayan

Departments of Nuclear Medicine and 1Cardiology, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India.

Aim: To compare left ventricular ejection fraction (LVEF) estimated using 99mTc- Sestamibi gated SPECT and 2D echocardiography in different subgroups of patients based on the body mass index (BMI). Materials and Methods: We retrospectively compared resting LVEF estimated by 99mTc-Sestamibi gated SPECT MPI & Echocardiography. Results: A total of 155 patients, age (mean, SD) 55.6 ± 10.9, were evaluated, who were referred to Department of Nuclear Medicine for 99mTc-Sestamibi gated SPECT imaging. 123/155 patients were males, while 32/155 were females. In all patients Echocardiography was performed within one week of SPECT study. Cardiac SPECT study was done on GE Discovery NM 670 Gamma Camera. Quantitative analysis was performed using Xeleris Workstation v 4.0 (GE) & Emory cardiac tool box™ V3.1. Patients were sub grouped based on gender & body mass index (BMI). Correlation coefficient (r) was calculated between two modalities, for entire population and also in subgroup of patients (BMI <18.5, 18.5-24.9, 25.0-29.9, ≥ 30 Kg/m2). Strong correlation is seen between two modalities in entire patient population (r= 0.85, p<0.001), in male patients, (r = 0.86, p<0.001), in patients with BMI in the range of 25.0-29.9 (r=0.87, p <0.001) and <18.5 (r=0.87, p < 0.001). Also, there is good correlation in sub group of patients with BMI 18.5-24.9 (r=0.83, p-0.001) though not very strong correlation is seen in obese patients with BMI ≥ 30 (r=0.761, p< 0.001). Conclusion: Our study shows good concordance between LVEF values estimated by QGS & echocardiography in entire study population. Though the correlation was not very strong in obese patients with BMI > 30 kg/m2.


   PP7: Role of F-18 FDG positron emission tomography in diagnosis and response assessment of arteritis and its correlation with arterial wall thickness on computed tomography Top


Punam Bhoge, Shwetal Pawar

Department of Nuclear Medicine, Seth G S Medical College and KEM Hospital, Mumbai, Maharashtra, India.

Objectives: To understand metabolic activity of arteritis at diagnosis and after steroid treatment or reactivation and its correlation with arterial wall thickening measured on CT. Materials and Methods: 30 patients are studied during Jan'17 to July 19 (22 Females, mean age: 36.4 yrs; 8 Males, mean age: 29.6 yrs) amongst which 16: Takayasu arteritis, 2: PVD, 1: miscellaneous and diagnosis was awaited in 11. 19 patients were on steroids and 11 were not. 18F-FDG (3.7 MBq/Kg) was injected, at 60 min post-18F-FDG injection PET (head to toe) scan with contrast 3 phase CT was done. On PET SUVmax of arterial wall (at maximum thickness measured on CT), liver and mediastinum was noted. Visual grading of vascular wall was done as - Grade 0: No uptake (≤ mediastinum), Grade 1: < liver, Grade 2: = liver (may be PET positive), Grade 3: > liver: (PET positive). On CT maximum thickness of large arteries was measured into 3 categories as: mild (≥2 mm), moderate (≥3 mm), severe (≥4 mm). The arterial wall thickness on CT and FDG uptake were correlated to find out metabolically active disease. Results: Among 11 patients for diagnosis (Pre-therapy)- moderate thickening with grade 1: 1 (9.1%) and grade 3: 2 (18.2%), whereas severe thickening with grade 0, 1, 3 was noted in 1, 2, 5 (9.1%, 18.2%, 45.5%) patients respectively. Among diagnosed 19 patients (post-therapy): mild thickening with grade 0: 2 (10.5%) and grade 1: 2 (10.5%);moderate thickening with grade 0: 2 (10.5%) whereas severe thickening with grade 0, 1, 3: 6, 6, 1 (37.5%, 37.5%, 5.3%). Conclusion: In patients of suspected and proven arteritis, where CT shows wall thickening in 100% pts; PET showed active disease in 26.67% (3.3% post therapy may be reactivation or relapse, 23.34% pre-therapy) and resolving disease in 73.33%.


   PP8: Feasibility of lower acquistion time with IQ SPECT in myocardial perfusion imaging Top


T. Saranya, Shelley, Indirani, Aashish Gambir

Apollo Hospital, Chennai, Tamil Nadu, India.

IQ SPECT-CT Consists of Smartzoom Cardio Centric and 3D iterative SPECT Reconstruction and makes it possible to perform myocardial perfusion imaging scans in a short time. Aim: IQ SPECT-CT can reduce myocardial perfusion acquisition time to one fourth (14 seconds/view) of that of a standard SPECT procedure. Further reduction of the acquisition time to one eighth of the standard time (7 seconds/view) was evaluated. Methods: 30 patients with suspected (or) diagnosed CAD underwent Rest and / or Stress study in Tc99m SestaMIBI myocardial perfusion imaging protocol using Smart zoom IQ collimator. Two consecutive SPECT acquisitions 14 seconds and 7 seconds were performed. Electrocardiogram – Gated image were reconstructed with & without attenuation correction. Polar maps were generated and visually scored by two blinded NM physicians for image quality and perfusion defect in 17 segments. Results: 1) Image Quality: Scored higher with the 14 seconds view acquisition both with and without AC. The 7 seconds image and the 14 seconds image with Attenuation correction were comparable images. Whereas Non Attenuated correction images were not comparable. 2) LVEF: no significant difference was noted between LVEF calculated using 7 second and 14 second image datasets (t=1.004; p=0.323). strong positive correlation was observed between the two datasets (Pearson's r=0.95; p < 0.00001). 3) Summed Scores calculated for AC and NAC image datasets did not show any significant difference [AC à t= -1.92; p= 0.06] [NAC à t= -1.18; p=0.24]. 4) Perfusion defect size [TPD]: No significant difference was noted for perfusion defect size in NAC images [t=-1.18; p= 0.24]. However, AC images demonstrated significant difference between defect size [t=-2.62; p= 0.013], defect on 7 seconds image slightly more than 14 seconds image. Strong correlation was demonstrated between perfusion defect size for AC and NAC data subsets (AC: Pearson's r=0.997; p < 0.00001; NAC: : Pearson's r=0.998; p < 0.00001). 5) Relative uptake score: For individual segments: No significant difference was observed for any image segment 1 to 17 for AC or NAC images. 6) Image quality: For each segment and overall image quality, significant difference was noted with 14 second image sets apparently superior to 7 second dataset. However, none of the patient had a IQ SPECT score<3 suggestive overall adequate image quality. Conclusion: Image Quality with 7 seconds acquisition was found to be comparable in AC image to previously validated 14 seconds acquisition. Reduced acquisition time with comparable image quality is possible only with the use IQSPECT with CT based attenuations. It Provide patient comfort, However needs more clinical evaluation needed.


   PP9: Gating artifact in a standard 8 frame gated myocardial perfusion imaging acquisition: Can it affect quantitation of left ventricular ejection fraction in cardiac myocardial perfusion imaging studies Top


Bannore (Upadhye) Trupti, B. Malpani, Nawab Singh Baghel, Sharmila Banerjee

Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

Background: Cardiac Myocardial Perfusion Imaging (MPI) study is a complex physiologic imaging process which is subject to several pitfalls and artifacts that can limit the utility of the study. Errors can occur at any stage of acquisition and processing of the raw data. However, gating errors are the most neglected ones and can be easily missed. These errors may have an effect on the final output. Aim: To study the importance of viewing a linogram and/or sinogram data in identifying gating errors in a cardiac MPI study. Methods: A forty eight year old female patient reported for a rest MPI study was injected approximately 333 MBq (9 mCi) of 99mTc-MIBI and subsequent imaging was carried out as per the routine Standard Operating Procedure (SOP) on a dual head gamma camera. The raw data was processed using auto-cardiac software and Left Ventricular Ejection Fraction (LVEF) was calculated using Emory Cardiac Tool Box (ECTB) software. The data on processing showed an abnormal sinogram and linogram with few scattered hot spots, which on further analysis revealed very high counts in a few gated frames of the acquisition. The data was reacquired with the same SOP and reanalyzed to check for any abnormality in the linogram or sinogram. Both the studies were further analysed for any discrepencies. Results: Both the data showed discrepencies in the results obtained following processing and analysis. The data with gating error showed very high counts in few frames which lead to further discrepency in the calculated quantitative parameters. The flickering or the bright dots abnormality or artifact can be easily seen if one observes the linogram and/or the sinogram during data processing. Conclusion: The sinogram and/or linogram reverted to normal on reacquisition. The visual slice display and polar map was not significantly affected in this case. The quantitative parameters were affected as the counts in the projections were abnormally increased. Thus, it is of prime importance for a clinician to look for the sinogram &/or linogram data not just for motion correction but also to detect such gating artifacts that may hamper the quantitation leading to erroneous output.Hypothesis: The data is a pictorial representation of how the linogram and/or the sinogram can aid in identifying the flickering or hot pixel artifact error and it does affect the LVEF but since it is a single patient data it cannot be applied for all patients and a percentage change in the LVEF cannot be determined. The LVEF is affected depending on which frames in the gated SPECT (Single Photon Emission Computed Tomography) projection receive fewer beats statistically hence quantitation of the same is difficult. This artifact is commonly seen if the gated acquisition is of 16 frames or more i.e dividing each cardiac rhythm into 16 frames or more thus is not expected in a 8 frame gated cardiac acquisition. We hypothesize that the linogram and/or sinogram got corrected after reacquisition as there were no gated frames with higher counts.


   Oral Presentation: Nephro-urology Top



   OP1: Comparison of plasma sample based GFR estimation with Gates' method using two different kidney depth formulae in kidney donors and patients with chronic kidney disease Top


Shagun Thakur, Sarika Sharma

Department of Nuclear Medicine, PGIMER, Chandigarh, India.

Aim: The aim of the study was to compare the camera based (Gates' method) and plasma based (Russell's method) GFR estimation techniques, in voluntary kidney donors and patients of chronic kidney disease using 99mTc-DTPA. Materials and Methods: A total of 42 patients (17 M: 25 F) with mean age of 47.5±11.4 years were enrolled in the present study. Seventeen patients had Chronic Kidney Disease (CKD) with mean Creatinine: 3.6 ± 1.8 mg/dl and mean Urea: 105.4 ± 46.0 Grade II to IV. Twenty-five patients were voluntary kidney donors (VKD) with mean Creatinine: 0.8 ± 0.1 and mean Urea: 24.1 ± 6.6. Following intravenous bolus injection of 99mTc-DTPA (3.7 ± 0.4 mCi) dynamic images were acquired on a gamma camera. The images were then processed by Gates' method, using Emory and Itoh kidney depth calculation formulae. For plasma sampling, 2 ml of blood samples were collected after 1 hour, 2 hours and 3 hours post injection in heparinized sample tubes. Counting was done the next day on a calibrated NaI well-counter. The GFR values were statistically analyzed. Results: The mean Normalized GFR was 26.1 ± 16.5, 37.3 ± 18.6 and 38.9 ± 21.8 ml/min/1.73 m2 by Russell's method, Gates' method (Emory Formula) and Gates' method (Itoh Formula) respectively for CKD group of patients. Whereas for the VKD group of patients the mean NGFR values were 94.0 ± 20.0, 87.0 ± 18.4, 88.0 ± 19.9 ml/min/1.73 m2 by Russell's method, Gates' method (Emory Formula) and Gates' method (Itoh Formula) respectively. The correlation coefficient between NGFRPS and NGFRE came out to be 0.370 (P< 0.068), and between NGFRPS and NGFRI was 0.371 (P<0.068) for VKD patients. Conclusion: Gates' method was found to be equally accurate and precise as plasma sampling method for GFR measurement in CKD group of patients. A weak correlation was observed between NGFR values of plasma sampling method and those computed by Gates' method in VKD patients. Gates' method was found to be a weak technique for GFR estimation in VKD group in our set of patients, suggesting that plasma sampling technique should be preferred over Gates' method.


   Poster Presentation: Nephro-urology Top



   PP1: Comparison of glomerular filtration rate measured by simple plasma techniques and Gates method in voluntary kidney donor Top


Danie Kingslin Heck, Julie Hephzibah, Nylla Shanthly, Regi Oommen

Department of Nuclear Medicine, Christian Medical College, Vellore, Tamil Nadu, India.

Aim: GFR is a valuable measurement in assessment of renal patients. Aim of this study was to compare Gates camera based method and a simplified method for single day calculation using Russel's plasma clearance method instead of urine sampling and weighing method. Materials and Methods: Thirty Voluntary kidney donors (VKD) referred for GFR estimation were analysed. Age range 45-62 years. Following Technetium-99m diethylene triamine penta acetic acid (DTPA) injection in one arm dynamic images were acquired in gamma camera for gates GFR, venous blood samples were collected from contralateral arm at 60 and 180 minutes through an indwelling venous cannula or direct collection by syringe. One ml of plasma from each sample were counted in an automatic gamma counter for 1 min. Plasma at 60 min and 180 min were used for double plasma sample method (DPSM) and plasma sample at 180 min used for single plasma sample method (SPSM). Russell's estimation for SPSM and DPSM were used for calculating GFR, Gates method GFR was calculated by using the available commercial software.

1. Single plasma clearance: Russell's method: GFR, in ml/min = A ln D/P + B; 1. Where: A = −0.278T + 119.1 + 2450/T, B = 2.886T − 1222.9 − 16820/T, D = Total injected dose counts (cpm), P = Plasma activity (cpm/ml), T = Sampling time (180 min).

Results: SPSM correlated well with DPSM. Mean SPSM and DPSM GFR (ml/min) was 111.4 and 114.2 respectively, Gates GFR was 92 ml/min. Minimum plasma clearance GFR was 89, 88.8 ml/min and for Gates 61 ml/min. Gates GFR estimation was not correlating with SPSM and DPSM. Though plasma clearance method is cumbersome, with Microsoft EXCEL program the GFR values can be calculated in the same day without using the weighing method. Thereby unaffecting the reproducibility of the results inspite of a cumbersome formula. By meticulous plasma separation and counting the reproducibility is maintained. Conclusion: When measuring GFR in a routine clinical setting, we recommend SPSM as the first choice. Our analyses show Gates GFR underestimates the values. And the difference between SPSM and DPSM are almost similar with a difference of 3-4 ml/min. Gates camera based method can be used for differential GFR and for total GFR estimation plasma sampling methods may be appropriate.


   PP2: Glomerular filtration rate in the elderly Voluntary kidney donors and renal reserve analysis: A single-center study Top


Lokeshwaran Madurai Kalimuthu, Kavali David Jaya Prakash, Vineet Mishra, Bela Jain, Ashutosh Parashar, Manish Ora, Sukanta Barai, Sanjay Gambhir

Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.

Objective: The aim of this study was to measure the glomerular filtration rate in the elderly voluntary kidney donor (VKD) and to measure renal function reserve. Methods: VKDs with age more than 60 years were considered for the analysis. All the subjects were normotensive, non diabetics, normal body mass index, preserved renal functional parameter, normal USG abdomen and absence of any clinical history suggesting renal impairment. After adequate oral hydration, 1mCi of Tc99m-diethyl-triamine-penta-acetic acid (DTPA) was administered intravenously and glomerular filtration rate (GFR) was obtained from calculating plasma clearance of Tc99m-DTPA by obtaining two venous blood samples at 60 min and 180 min after injection using the modified Russell's. Global GFR was normalised to patients' body surface area (BSA), which was calculated by Dubois and Dubois Formula. On the second day Stimulated GFR estimation (GFRAAI) and renal functional reserve (RFR) study was done after intravenous amino acid loading. Adequate RFR was considered as more than 20% increase in GFR with respect to baseline. Results: Total 74 elderly VKDs were included in the final analysis (male-33 and female-41). The study revealed that the mean age of the study population was 65.9 ± 11.3 years. The mean baseline GFR was 66.04±10.1 ml/min/1.73 m2 BSA, GFRAAI after protein loading was 75.9± 9.8 ml/min/1.73 m2 BSA. Thirty two percent of the VKD (male-27% and female-36.5%) had adequate renal reserve, whereas 68 % of the elderly VKDs were found to have an inadequate renal reserve. Conclusion: GFR measurement is a mandatory investigation for evaluation of prospective voluntary kidney donors. Pre donation GFR measurement not only identifies suitable potential donor but it also predicts the future trend of GFR in both donor and recipient. In our study we found that baseline GFR of the elderly Indian VKD was less and only one third of them showed adequate response to the amino acid stimulation. Two third of the elderley donors have inadequate RFR inspite of having normal baseline GFR for their age, which may have risk of developing renal dysfunction in future.


   PP3: To compare plasma clearance based glomerular filtration rate measurement with serum creatinine-based estimate glomerular filtration rate measurement methods (Schwartz formula) in patients with posterior urethral valves Top


Lokeshwaran Madurai Kalimuthu, Sukanta Barai, Kavali David Jaya Prakash, Vineet Mishra, Vijay Singh, Manish Ora, Sanjay Gambhir

Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.

Objective: Comparison of plasma clearance based GFR measurement with serum creatinine-based eGFR methods (Schwartz formula) in patients with posterior urethral valves. Methods: A retrospective analysis of the patients with Posterior urethral valve (PUV) referred for glomerular filtration rate measurement (GFR) was done. Cystoscopic diagnosis of PUV was made and the patient underwent valve fulguration. After adequate oral hydration, 1mCi of Tc99m-diethyl-triamine-penta-acetic acid (DTPA) was administered intravenously and glomerular filtration rate (mGFR) was measured from calculating plasma clearance of Tc99m-DTPA by obtaining two venous blood samples at 60 min and 180 min after injection using the modified Russell's. mGFR was normalized to patients' body surface area (BSA), which was calculated by Dubois and Dubois Formula. Creatinine clearance based Schwartz formula was used to estimate the GFR (eGFR). Further patients were categorized into 6 stages of chronic kidney disease in accordance with the National Kidney Foundation (NKF) classification. Results: Total 62 patients with a diagnosis of PUV were enrolled. The mean age was 8.5 ± 6.5 years and 56 of them were male. Patients had mean serum creatinine of 1.15± 0.9 mg/dl, blood urea nitrogen 19± 15 mg/dl, and albumin 4.4± 1.61 gm/dl. Mean mGFR was 61.6±31.8 ml/min/1.73 m2 body surface area (BSA) and mean eGFR (Schwartz formula) was 56.28± 24.4 ml/min/1.73 m2 BSA. As per NFK classification, 14, 21, 13, 8 and 6 patients were categorized into CKD stage I to V respectively. Conclusion: More than three fourth of the PUV patients have low mGFR (CKD II-V). eGFR overestimate the GFR in all the subgroups. There was no significant correlation between the eGFR and mGFR in all stages of CKD except for stage III. In view of loss of muscle mass in the CKD patients, the eGFR is not sensitive for the measuring the true GFR in PUV patients and mGFR is recommended.


   PP4: 99mTc DTPA scintigraphy in early renal graft dysfunction in the transplant kidney Top


Babita Kumari Drolia, Ritu Verma, Ethel Belho, Suneel Kumar Malipedda

Sir Ganga Ram Hospital, Delhi, India.

Aim and Objectives: To evaluate the diagnostic accuracy of 99mTc DTPA for acute renal graft complications. Materials and Methods: This study is conducted in the Department of Nuclear Medicine & PET-CT, Sir Ganga Ram Hospital, New Delhi. We analyzed retrospective and prospective renal transplant patients with suspected complications. We included renal transplant patients >18 years with graft dysfunction who needed renal biopsy. On 99mTc DTPA scan, renal perfusion, cortical uptake and drainage pattern are noted by 2 experienced nuclear medicine physicians. By this scintigraphy, we evaluated the vascular perfusion and function of the graft and diagnosed complications as ATN (Acute tubular necrosis) and AR (Acute rejection). Histopathological reports were collected. Results: Between March 2016 and August 2019, 20 patients (14 males, 06 females, and mean Age 34 ± 12.3 years, Range 15-50 years) underwent renal scintigraphy study in our Nuclear Medicine department with post-transplant complications were included in this study. The histopathology reports of 18 patients were available and were collected and correlated with renal scintigraphy scan findings. We have reported 12 cases as AR and 6 cases as ATN. Out of 12 cases reported as AR, histopathology revealed 10 cases as AR and 2 as ATN. Out of 06 cases reported as ATN, histopathology revealed 04 cases as ATN and 02 as AR. Conclusion: Renal scintigraphy with 99mTc-DTPA showed a good overall accuracy in the detection of acute renal graft complications. It can be used as a reliable tool for routine evaluation in renal transplant cases.


   PP5: Formulation of lyophilized cold kit for instant preparation of 99mTc-Inulin and its scintigraphic evaluation for renal function estimation Top


Gaurav Mittal, Thakuri Singh, Harish Rawat, Amit Kumar Tyagi, Abhinav Jaimini

Department of Nuclear Medicine, Institute of Nuclear Medicine and Allied Sciences, Delhi, India

Aim: Determination of glomerular filtration rate (GFR) requires utilization of a substance that is freely filtered by the glomerulus and is neither secreted nor reabsorbed by the renal tubule. Inulin, a fructose polysaccharide, is known to possess these characteristics as a marker for GFR and is considered the gold standard for estimating GFR. The inherent difficulties in the use of inulin clearance as a measure of GFR include the necessity for a constant-infusion apparatus and awkward chemical analyses of blood and urine samples. Besides, no reproducible method to radiolabel inulin with a suitable radiotracer was ever developed. Consequently, other substances like DTPA are being used as substitutes for inulin, but lack the required accuracy. We here propose a method to radiolabel inulin with Technetium-99m pertechnetate for the first time, which may be used for GFR estimation, imaging and differential renal function estimation. Methods: A cold freeze-dried kit of Inulin consisting an appropriate amount of Inulin, Stannous chloride as a reducing agent and stabilizer was developed. The kit was reconstituted with 99m Technetium pertechnetate for labeling. Labeling efficiency was measured by instant thin layer chromatography (ITLC-SG). The normal biodistribution and dynamic scintigraphic imaging was carried out in rabbits. Results: The radiochemical purity of Inulin was achieved >97% when mixed with requisite amount of 99m Tc-pertechnetate. The labeled preparation was found to be sufficiently stable in-vitro as well as in-vivo. Blood clearance in rabbits was rapid and biphasic in the pattern. Scintigraphic study in rabbits showed excellent tracer extraction and background clearance. Conclusion: Measurement of inulin clearance remains the gold standard for assessing GFR, however, most laboratories cannot routinely measure inulin, which makes this test impractical. This study shows 99mTc labeled inulin to be stable in saline and serum up to 6 hours. It is also mimicking the typical clearance pattern of unlabelled inulin in experimental rabbits. Thus, 99mTc-labeled inulin can potentially be used for easy and accurate determination of GFR and differential GFR.


   PP6: A pilot study using normalised residual activity: A technique to minimise the renogram scan time in infants and children Top


K. B. Sricharan

Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India.

Aim: The aim of this study is to assess the diagnostic utility of Normalised residual activity (NORA) in reducing the total acquisition time, by estimating the renal emptying during the 99m-Tc EC (Ethylene dicysteine) renogram acquisition and interpreting their values with delayed images in obstructed and un-obstructed kidneys. Materials and Methods: A total of 42 cases, of which 34 male and 8 female children with mean age group of 1.38 ± 2.00 years, were included in this study between September, 2014 to March, 2015. These cases were referred to Department of nuclear medicine in view of clinical suspicion of obstruction and inconclusive findings on various conventional imaging modalities such as ultrasound (US) examination, intravenous urography (IVU) or computerized tomography (CT) of abdomen or magnetic resonance urography (MRU) and renal function tests including serum creatinine level in all cases. All 42 cases underwent renogram of 30 mins. acquisition after administration of 1.5 ± 0.3 mCi of 99m-Tc EC with F+0 protocol with initial perfusion images with 2 sec/Frame for 60 sec. followed by dynamic images of 15 sec/Frame for later 29 mins. with 128*128 matrix and zoom of 1.2 to 2.0 depending on age of child by using low energy high resolution all-purpose collimator. NORA was calculated by taking counts at 3rd and 20th mins. of acquisition for all cases and correlated with delayed images. Results: We have considered NORA cut off value of ≤ 0.5 as normal un-obstructive drainage pattern. On correlation with delayed images of both left and right kidneys, NORA parameter showed concordance of 94% and discordance of 5% with delayed images in total of 84 kidneys with measure of agreement i.e. Cohen's kappa (κ) of 0.865 with p value <0.001, which is statistically significant. Conclusion: From this study, we can conclude that NORA is the parameter, which can be used in early assessment of obstructive drainage pattern, particularly in post Pyeloplasty cases in infants and children where total duration of imaging can be reduced by avoiding delayed image acquisition.


   PP7: Delineate suspected focus of infection or inflammation in renal transplant recipients: Phenomenal role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography Top


Sunita Sonavane, Tukaram Jamale, Priyanka Verma, Ramesh V. Asopa, Sutapa Rakshit, Trupti Upadhye, Swati

Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

Aim: The aim of this retrospective study is to evaluate to clinical implications of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) in suspected infection or inflammation in renal transplant recipients. Materials and Methods: A retrospective study including 35 renal transplant recipients (26 males and 9 females) referred for 18F- FDG PET/CT (Lasix primed) to delineate suspected focus of infection or inflammation from tertiary care centre to our institute since 2015- till date. Infection is a diagnostic dilemma because of the limitations of conventional post contrast imaging procedures, especially in post transplant/ chronic kidney disease patients. The final diagnosis was confirmed either histopathologically or by clinical follow-up. Results: Imaging findings from 18F-FDG PET/CT were analysed in 3 categories depending upon the clinical presentation i.e. 21 patients with recurrent genitourinary (GU) symptoms, 9 patients with unexplained pyrexia (PUO) and 5 patients with skeletal pain. In first category of twenty one patients with GU symptoms- eight were diagnosed to have pyelonephritis, 1 was diagnosed having epididymo-orchitis, 12 had scans post antibiotic therapy to ruleout any residual infection and were normal, thus ruling out any residual infection. Of the 9 patients with PUO associated with weight loss and diarrhoea- 4 were detected to have pulmonary tuberculosis, one was incidentally diagnosed to have thyroid cancer, 1 patient proved to have fungal esophagitis and 3 patients had normal scans. Five patients presented with skeletal pain, of which, 2 patients were diagnosed with vertebral Koch's, 1 patient had musculoskeletal abcess, 1 diagnosed with invasive aspergillosis and 1 had normal scan. FDG PET/CT findings thus, changed management by accurate diagnosis of localization of infection/ disease focus in 19/35. FDG PET/CT aided in concluding complete eradication of infection and guided in treatment response evaluation and discontinuation further antibiotic therapy in 16/35 patients. Conclusion: This study showed that whole body 18F-FDG PET/CT is an effective method to delineate suspected focus of infection or inflammation in renal transplant recipients, contributes in followup assessment and evaluating response to antibiotic therapy additionally guiding the duration of antibiotic therapy in recurrent pyelonephritis.


   PP8: To compare the measured glomerular filtration rate using Tc99m-diethyl-triamine-penta-acetic acid with various creatinine-based equation in the voluntary kidney donors Top


Lokeshwaran Madurai Kalimuthu, Sukanta Barai, Kavali David Jaya Prakash, Vineet Mishra, Ayush Mishra, Manish Ora, Sanjay Gambhir

Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.

Objective: The aim of this study was to compare plasma clearance based GFR measurement (mGFR) to the various creatinine-based eGFR estimation. Methods: All the healthy VKDs with age more than 18 years were considered for the analysis. All the subjects were normotensive, nondiabetics, normal body mass index, preserved renal functional parameter, normal USG abdomen, and absence of any clinical history suggesting renal impairment. After adequate oral hydration, 1mCi of Tc99m-diethyl-triamine-penta-acetic acid (DTPA) was administered intravenously and glomerular filtration rate (GFR) was obtained from calculating plasma clearance of Tc99m-DTPA by obtaining two venous blood samples at 60 min and 180 min after injection using the modified Russell's. Global GFR was normalized to patients' body surface area (BSA), which was calculated by Dubois and Dubois Formula.

The glomerular filtration rate estimation was done using plasma clearance. Modification of the diet in renal disease study (MDRD), Cockcroft and Gault formula and CKD-EPI formula were used. Results: In this study, 651 prospective VKD were analyzed. The mean age was 45.78± 26.16 years. Mean serum creatinine was 0.85± 0.14 mg/ dl, blood urea nitrogen was 10.86± 1.12 mg/dl and serum albumin was 4.5± 0.28 gm/ dl. Mean mGFR was 79.98±13.43 ml/min/1.73 m2 body surface area (BSA). Mean eGFR by MDRD, Cockcroft gault and CKD-EPI were 82.67± 11.20 ml, 89.69± 28.80 ml and 106± 34.23 ml/min/1.73 m2 BSA respectively. Conclusion: There is a significant correlation between mGFR and eGFR estimated by MDRD in 18-30, 46-60 and >60 years age groups. A significant correlation was noted between the mGFR and eGFR by Cockcroft Gault equation only in more than 60 years group. CKD-EPI formula shows a significant correlation in the 18-30 and more than 60 years age group. In general, all the equation tends to overestimate GFR. eGFR calculated by various equations does not perform well in all age groups. For potential VKD mGFR is recommended rather than eGFR.


   Oral Presentation: Thyroid Top



   OP1: Pattern of recovery of serum TSH in patients with suppression of hypothalamic-pituitary-thyroid axis after low dose radioiodine ablation Top


Abhishek Behera, Shreya Datta Gupta, Chandrasekhar Bal

All India Institute of Medical Sciences, New Delhi, India.

Patients of Graves' disease with subclinical hyperthyroidism at 3 months post radioiodine ablation may represent euthyroid patients with a delayed recovery of the hypothalamic-pituitary-thyroid axis or patients with residual thyrotoxicosis. In patients with delayed recovery of hypothalamic-pituitary-thyroid axis there is limited literature suggesting duration of delay of the TSH recovery. Thus, this study was undertaken to generate initial estimates with regard to the same. All sequential patient records beginning from 01-01-2005 of patients treated with low dose radioiodine for treatment of hyperthyroidism in our institute were retrospectively reviewed for the purpose of this study. Only asymptomatic patients with normal serum T3, T4 and low serum TSH levels at 3 months post radioiodine ablation and availability of at least one clinical visit at 6 months and 1 year post low dose radioiodine ablation of thyroid gland were retroactively followed. Normal/low serum T3, T4 levels s with low serum TSH at 3 months and absence of any rise in T3/T4 levels or any symptoms of hyperthyroidism till one year follow up in patient was considered the gold standard for diagnosis of central axis suppression. The patient status at 6 months and 1 year follow up was classified into either of two groups – TSH not recovered (TSH < 0.5 uIU/ml) or TSH recovered (TSH > 0.5 uIU/ml) at 6 month and at 1 year follow ups for each of the patients. Percentage of patients with TSH recovery at 6 month and 1 year were estimated and comparison of serum TSH values between 3 month and 6 month follow up was done to look at any change between the same. Correlation analysis was done with age, gender, duration of symptoms, H/O Anti-thyroid drugs, baseline serum TSH and radioiodine uptake to determine their predictive value for length of TSH suppression. Data of 61 patients was analysed, 37 patients had serum TSH levels > 0.5 uIU/ml at the 6 month follow up. At the one year follow up, 49 patients had serum TSH > 0.5 uIU/ml. Thus 60.7 (48.44-72.96) percent of the patients had TSH recovery at six months and 80.3 (70.32-90.28) percent of the patients had TSH recovery by 1 year. Thus in our estimate, likelihood of TSH recovery is 60.7% (48.44% - 72.96%) at 6 months and 80.3% (70.32% - 90.28%) at 1 year. The median serum TSH levels at 3 months was 0.3 uIU/ml (UD – 0.4 uIU/ml), whereas it was 1.6 uIU/ml (UD – 150 uIU/ml) at the 6 month follow up. This difference was found to be significant (p value <0.001). Univariate correlation analysis was done between baseline features such as patient age, gender, duration of symptoms, H/O Anti-thyroid drugs, baseline serum TSH and radioiodine uptake (2 hour and 24 hour) and outcome at 6 months and 1 year. Only a weak correlation was found between patient age and outcome at 1 year (r = -0.26, p = 0.04). No other significant correlations were found between baseline patient features and outcomes at 6 month or 1 year follow up.


   OP2: Long-term clinical outcome of low risk differentiated thyroid cancer patients who have not received iodine 131-radioactive iodine therapy Top


Avinash Tupalli, Srinivasa Reddy Konudula, Nikhil Mohan, Arunav Kumar, Chandrasekhar Bal

All India Institute of Medical Sciences, New Delhi, India.

Introduction: Post definitive surgery, all thyroid cancer patients are stratified into low, intermediate or high risk categories and this risk adopted management of individual patients, utilize this stratification to guide surveillance and therapeutic management decisions. Since, the disease specific mortality being low and risk of recurrence of around 1-3% in low risk differentiated thyroid carcinoma patients, Radioactive iodine (RAI) therapy is not routinely recommended according to American thyroid association (ATA) guidelines, which is a weak recommendation and has low quality evidence. This study intends to know the clinical outcome of low risk thyroid cancer patients who underwent surgery, not received iodine therapy and is being followed up in our institution. Materials and Methods: This retrospective study had been done in department of nuclear medicine, AIIMS and include 144 low risk thyroid cancer patients who did not receive iodine therapy had been analysed for time of progression free survival. Results: out of 144 patients, 82 were female and 62 were male. The mean age was 38 years and 44 years for female and male respectively. The follow up period ranged from 5 to 236 months with average follow up of 122 months. 6 out of 144 patients (4%) had recurrence and recurrence occurred at time points range of 70 to 178 months, average of 138 months. Patients in the recurrence group had statistically significant (p-value 0.007165) higher mean immediate post operative Thyroglobulin (Tg = 14) compared to patients with no recurrence (Tg = 4). No statistically significant difference was found in the 131-I radioactive iodine uptake (RAIU) in recurrence and non-recurrent group. Overall PFS was 122 ± 72 months. Conclusion: Low risk thyroid carcinoma with only follow up (no iodine therapy) has good prognosis. Risk of recurrence is 4% in our study and recurrence occurred at around average of 138 months of follow up from diagnosis. Patients with higher mean Tg (>14 ng/ml) has higher chance of recurrence.


   OP3: Bone metastases in differentiated thyroid carcinoma: A ten year review in a tertiary health care centre Top


Junita Rachel John, Julie Hephzibah, Regi Oommen, Nylla Shanthly, David Mathew, Anish Jacob Cherian, S. Elanthenral

Christian Medical College, Vellore, Tamil Nadu, India.

Introduction: Bone metastasis (BM) from differentiated thyroid carcinoma (DTC) is associated with lower survival and its management poses a challenge. The objective of the study was to evaluate the clinical characteristics of patients with BM, therapeutic outcomes and prognostic factors. Materials and Methods: Of 2715 consecutive post-total thyroidectomy DTC patients between 2009 to 2019, 109 had bone metastases detected on Thyroid whole body scintigraphy (TWBS). The details of the clinical characteristics of these patients, histopathology, treatment protocols and outcomes were analysed. Patients with minimum one year follow up or received at least two radioiodine therapy (RIT) post thyroidectomy, were included in this study. Patients who underwent RIT elsewhere and those who defaulted treatment were excluded. Results: Among 109 DTC patients with bone metastases, 90 (83%) fulfilled the study criteria (M: F – 43:47, mean age: 53 years, range 13-75 years, 64 (71%) papillary carcinoma, 15 (17%) follicular carcinoma and 11 (12%) poorly differentiated thyroid carcinoma). BM were synchronous in 81 (90%) and 61 (68%) had BM related symptoms. Multiple sites of BM were present in 63 (70%) patients. Twenty two (24%) patients had non-osseous metastases (lung being most common). All patients received RIT (85-120 mCi/treatment); cumulative dose > 600 mCi in 6. Mean follow up was 4.9 years. Nine (10%) patients had complete response (CR), 39 (44%) stable disease and 22 (24%) disease progression. Twenty (22%) were non-responders to RIT. All the patients with CR (mean age 48 years, range: 25-71 years) had papillary carcinoma, 7 (78%) had solitary bone involvement and 8 (89%) had metastases limited to the bone. Except for one patient, all (8/9) achieved complete remission with a single dose of RIT. Of 39 patients with stable disease (30 (77%) papillary carcinoma, 8 (21%) follicular carcinoma and 1 (2%) poorly differentiated thyroid carcinoma), 30 (77%) had multiple site BM and disease could be kept under control for mean period of 5.6 years. In 71 patients with a minimum follow up of 2 years, one patient died (2 year survival of 78.5%). Conclusion: Bone metastases from differentiated thyroid carcinoma are usually symptomatic and multifocal. The spread of thyroid carcinoma to bone offers a poor outcome in the management of these patients. Nevertheless, a single dose of 100 mCi of radioiodine therapy could achieve cure in patients with papillary carcinoma thyroid and solitary bone metastasis.


   OP4: Prospective comparison of 68Ga-RGD2 positron emission tomography/computed tomography with 18F-flourodeoxyglucose positron emission tomography/computed tomography in radioiodine refractory thyroid cancer Top


Ashwin Singh Parihar, Bhagwant Rai Mittal, Jaya Shukla, Rajender Kumar, Anish Bhattacharya

Department of Nuclear Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

Aim: Radioiodine therapy (131I) forms a principal cornerstone in the management of differentiated thyroid cancer. Radioiodine refractory differentiated thyroid cancer (RAIR-DTC) presents a challenge in terms of detection of structural disease in patients with evidence of biochemical disease and in treatment of the disease using alternate therapeutic modalities. The present study was conducted to compare the diagnostic accuracy (in terms of sensitivity and specificity) of 68Ga-DOTA-RGD2 PET/CT as a neo-angiogenesis imaging modality with 18F-FDG PET/CT, the current standard in diagnostic algorithm of RAIR-DTC and to evaluate the radiotracer avidity on 68Ga-DOTA-RGD2 PET/CT for potential theranostics. Materials and Methods: 44 patients of RAIR-DTC with a negative post-therapy 131I scan were prospectively enrolled after voluntary, informed consent. Serum thyroglobulin (S. Tg) and anti-thyroglobulin (ATg) measurements were done with levothyroxine withdrawal (thyroid stimulating hormone stimulated state) and 18F-FDG PET/CT and 68Ga-DOTA-RGD2 PET/CT studies were performed within one week of each other. Follow-up was done with histopathology/ S. Tg/ ATg/ conventional imaging. The findings of 18F-FDG PET/CT and 68Ga-DOTA-RGD2 PET/CT were compared with the reference standard to obtain sensitivity, specificity and overall accuracy. Degree of radiotracer uptake on 68Ga-DOTA-RGD2 PET/CT was described as tumor to background (T:B) and tumor to liver (T:L) ratios of standardized uptake value (SUV). Results: 68Ga-DOTA-RGD2 PET/CT detected a total of 123 lesions, with an overall sensitivity, specificity and accuracy of 82.3%, 100% and 86.4% respectively. 18F-FDG PET/CT detected a total of 144 lesions, with an overall sensitivity, specificity and accuracy of 82.3%, 50% and 75% respectively. Most commonly identified disease sites were nodal (82.9%), followed by thyroid bed lesions (10.5%). 82.1% patients positive on 68Ga-DOTA-RGD2 PET/CT showed lesional radiotracer uptake higher than liver (grade IV and V). Conclusion: 68Ga-DOTA-RGD2 PET/CT showed a similar sensitivity to, but higher specificity and overall accuracy than 18F-FDG PET/CT in detection of lesions in RAIR-DTC patients. This novel application of the angiogenesis imaging modality can prove useful in RAIR-DTC, especially in patients with negative/ suspicious 18F-FDG PET/CT. Further, since majority of patients (82.1%) positive on 68Ga-DOTA-RGD2 PET/CT showed radiotracer avidity towards the higher end of the spectrum (grade IV and V), novel 177Lu-based theranostics can be a potential treatment for these patients.


   Poster Presentation: Thyroid Top



   PP1: Significance of 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan in thyroglobulin-elevated negative iodine scintigraphy syndrome patients – A retrospective study Top


T. M. Suma, Tek Chand Kalawat

Sri Venkateswara Institute of Medical Sciences, SVIMS, Tirupati, Andhra Pradesh, India.

Background: The treatment for differentiated thyroid cancers (DTCs) usually includes definitive surgery followed by high dose radioactive iodine 131I therapy. Undetectable levels of Tg are expected after successful treatment. Stimulated Tg (serum thyroglobulin) is a sensitive marker of both residual and recurrent disease. However, patients presenting with thyroglobulin-elevated negative iodine scintigraphy (TENIS) syndrome have been a challenge for clinicians to decide further management. 18F-fluorodeoxyglucose (18F FDG) positron emission tomography/Computed Tomography (PET/CT) is widely used for detecting recurrent and metastatic disease in patients with differentiated thyroid cancer (DTC). Aim: To assess the relationship between 18F FDG PET/CT and serum thyroglobulin (Tg) levels in patients labeled as TENIS. Objectives: 1. To assess the utility of 18F FDG PET/CT in patients labeled as TENIS. 2. To select a Tg threshold level for the selection of patients who should undergo 18F FDG PET/CT scan and to assess likelihood of metastases in TENIS. Materials and Methods: Data from 24 patients with recurrent thyroid cancer with elevated Tg but negative post high dose whole body iodine scan from 2017 to 2019 was collected and analyzed retrospectively. 18F FDG PET/CT was performed in these patients and results were compared.

Results: Out of 24 patients, 11 (45%) were female and 13 (55%) were male patients. The mean age of the patients was 54.5 years (range: 22 y-85 y). 22 patients were histological proved as papillary carcinoma thyroid and 2 as follicular carcinoma. 20 out of 24 patients (83%) had positive 18F FDG PET/CT scan. 18 out of 22 patients (81%) with papillary thyroid cancers and 2 of 2 patients (100%) with follicular thyroid cancer had positive 18F FDG PET-CT findings. Patients with positive 18F FDG PET/CT findings had higher Tg levels. 20 out of 21 patients with Tg > 10 ng/mL had positive findings and 3 out of 3 patients with Tg < 10 ng/mL had negative findings. Only one patient had Tg > 10 ng/mL (10.7 ng/mL) had negative 18F-FDG PET-CT findings.

Conclusion: Our data suggest that, performing 18F-FDG PET-CT in TENIS patients would be more beneficial by considering Tg 10 ng/mL as a cutoff value. (Currently American Thyroid Association recommended cutoff of 10 ng/mL).Moreover, 18 F FDG PET/CT findings may help in optimizing the treatment.


   PP2: Diagnostic utility of dual use of Tc-99m pertechnetate and Tc-99m tetrofosmin for evaluation of thyroid nodules Top


Nisha Bhatia, Vandana Kumar Dhingra1, Saumya Kumari, Sampan Singh Bisht2, Anuradha Kusum3, Devinder Kumar Dhawan4, Vijayta Dani Chadha5

Departments of Nuclear Medicine, 2ENT and 3Pathology, Cancer Research Institute, Swami Rama Himalayan University, Dehradun, 1Department of Nuclear Medicine, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, 4Department of Biophysics, Panjab University, 5Centre of Nuclear Medicine, Panjab University, Chandigarh, India.

Background and Aim: The advent of advanced imaging techniques with high sensitivity have added significantly to the early diagnosis of thyroid nodules. The aim of present study was to evaluate the efficacy of dual use of 99mTcO-4 and Tc-99m tetrofosmin for differentiating malignant nodules from the benign nodules. Materials and Methods: Radionuclide perfusion scan was performed using gamma camera (e-Cam signature series) on total 23 patients which includes 5 males and 18 females with Mean age ± SD; 40.8 ±14.7 yrs and range (12-65 yrs). Tc-99m pertechnetate perfusion study was performed on all patients having thyroid nodules followed by static imaging after injecting 4-5mCi of Tc-99m pertechnetate. After 1 week, Tc-99m tetrofosmin perfusion study was performed on same group of patients followed by early and delayed images after injecting 8-10 mCi Tc-99m tetrofosmin. Results of radionuclide perfusion scan for both studies were compared qualitatively with post-surgical histopathology or fine needle aspiration cytology (FNAC). Results: Total 31 nodules were observed in 23 patients. Tc-99m pertechnetate scan reported were as showing cold nodules N= 28 [Malignant – 14, Benign-14] and hot nodules N=3 [Malignant-2, Benign-1]. Tc-99m tetrofosmin scan reported as showing cold nodules N= 7 [Malignant-6, Benign 1], and hot nodules N=24 [Malignant-10, Benign - 14]. All 6 malignant nodules showing no uptake (cold) on 99mTc-tetrofosmin were nacrotic and cystic in nature. Conclusion: Dual Tracer technique with Tc-99m pertechnetate and Tc-99m tetrofosmin could be utilized for immediately excluding most benign nodules and in selecting nodules for surgical intervention. In the present study we observed that a hypofunctioning nodule on Tc-99m pertechnetate but with high Tc-99m tetrofosmin uptake on early and delayed imaging may be suggestive of malignancy despite a benign FNAC result. This technique can be used for convenient and rapid diagnostic evaluation of thyroid nodules non-invasively. We suggest a combination of fine needle aspiration biopsy and dual use of Tc-99m pertechnetate and Tc-99m tetrofosmin as a routine diagnostic approach to thyroid nodules. However, further clinical studies in larger number of patients along with quantitative analysis required to establish the precise role of these radiopharmaceuticals.


   PP3: Thyroid parotid ratio in Tc99m thyroid scan for thyroid disorders Top


Danie Kingslin Heck, Sathya, Julie Hephzibah, Nylla Shanthly, Regi Oommen

Department of Nuclear Medicine, Christian Medical College, Vellore, Tamil Nadu, India.

Aim: To assess the ratio of Tc-99m pertechnetate thyroid uptake to parotid gland in thyroid disorders in Thyroid uptake study. Methodology: Retrospective study included 39 patients who underwent thyroid scintigraphy. Results: Of them, 4 patients were diagnosed to have hypothyroidism, 21 with thyroiditis, 3 with dyshormonogenesis, 4 with euthyroidism and 7 with hyperthyroidism. Calculation of the average thyroid counts from both lobes and bilateral parotid counts was calculated by ROI method using Gamma camera. The mean ratio thyroid to parotid are noted in all the groups of diseases and summarized in [Table 1]. Conclusion: Significantly higher T/P values are noted in Dyshormonogenesis and Hyperthyroidism and lower values are noted in Thyroiditis. Tc99m thyroid scan with estimation of T/P ratio is a simple test to quantitatively evaluate thyroid function instead of a more cumbersome 1-131 estimation. It also has lesser radiation dose, lesser duration and is a cost effective tool.
Table 1: T/P ratio in various disorders of thyroid

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   PP4: Genetic analysis of TBG-gene of a thyroid patient having TBG-deficiency Top


Smita Gawandi, J. Kumarasamy, Savita Kulkarni, Sharmila Banerjee

Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

Aim: Mutational screening of TBG-gene in patient with TBG-deficiency to unravel the cause of low TBG levels at the genetic level. Introduction: This study presents a case of a patient who had a history of consistently low total T4 & T3 and normal TSH & FT4. TBG-testing by Radioimmunoassay (RIA) confirmed presence of TBG-deficiency in her. She developed hypothyroidism over the period and is being treated for it. The screening of her blood relatives (4/14) from the three generations revealed X-chromosome linked genetic transmission of the trait. The TBG- gene is located as a single gene copy on the long arm of the X-chromosome (Xq21-22). This gene consists of 5 Exons of which 4 are coding. More than 20 mutations are reported in Exon 1 to 4 of TBG-gene which caused TBG-deficiency from various countries, but none from India so far. In order to determine cause of low TBG levels in the patient at the genetic level, all the four coding Exons of the TBG-gene were sequenced. Materials and Methods: TFT i.e. T4, TSH, FT4, AMA & TBG levels were estimated in patient's serum by (Radioimmunoassay) RIA & Immunoradiometric assay (IRMA) kits. The genomic DNA was extracted from whole blood sample by salting out procedure. For mutational screening, exon 1 to 4 of TBG gene of the patient were amplified by Polymerase chain reaction (PCR) using specific primers. The PCR products were purified and subjected to direct DNA sequencing. Results: The sequencing of Exon 1, 2 and 3 did not show any abnormality. However, a heterozygous frameshift mutation was detected in the Exon 4 of TBG gene of the patient. Conclusion: A mutation in TBG-gene was successfully detected in the patient having TBG-deficiency. This is a first report of TBG-deficiency from India to best of our knowledge. The patients with inherited TBG-deficiency should be assessed carefully as they are at a risk of development of hypothyroidism in future. More investigation of including genetic studies in the TBG-deficient patients are needed in future which will throw more light on correlation between genotype and phenotype (i.e. thyroid function). The knowledge about genetic abnormality in thyroid patients will be helpful to doctors to make more focused diagnosis and targeted treatment action plan as a part of personalized medicine.


   PP5: Coexistence of thyroid autoimmunity and thyroid cancer Top


Chandrakala S. Gholve, Sharmila Banerjee, Savita Kulkarni

Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

Introduction: Coexistence of thyroid cancer and autoimmune thyroid disorders (AITD) may arise due to the frequent occurrence of autoimmunity. The coincidence of differentiated thyroid cancer (DTC) with Hashimoto's Thyroiditis (HT) has been variably reported at between 0.5 and 22.5%. Thyroid peroxidase antibody (TPOAb) measurement is useful in diagnosing patients with AITD, and anti-thyroglobulin autoantibody (TgAb) is used to detect potential interferences with thyroglobulin (Tg) immunoassays. Tg is used as an exquisite tumour marker in DTC patients. Aim: Our study aimed at finding out the coexistence of thyroid autoimmunity in known cases of thyroid cancer patients, those approaching our OPD for follow-up; using TgAb and TPOAb measurement. Materials and Methods: The study comprised male (n=30) and female (n=62) DTC subjects in the age group of 18-70 yrs. Upper reference ranges for TgAb and TPOAb were established at 30 and 12 IU/ml respectively in our laboratory, using commercial isotopic kits from Immunotech, France. Results: In the total study subjects, the occurrence of TgAb and TPOAb were 17.3% (16/92) and 15.2% (14/92) respectively, and 26% (M/F ratio, 0.33) were positive for TPOAb and/or TgAb. Of the TgAb-positive subjects, 37.5% (6/16) were also TPOAb-positive, and of the TPOAb-positive subjects, 42.85% (6/14) were also TgAb-positive with M/F ratio of 0.2. Conclusion: In conclusion, significant co-occurrence of TgAb and/or TPOAb in thyroid cancer implies that autoimmunity does coexist with thyroid cancer and therefore, for better clinical management these patients (especially women) should have a careful follow-up. Nonetheless, few studies have reported that the presence of thyroid autoimmunity may indicate a better prognosis for thyroid carcinoma. Another consequence of this coexistence is methodological, pertaining to the use of Tg as a tumour marker in the presence of TgAb, thereby restricting its application in such patients. Subsequently, in such cases, for better management of DTC patients, TgAb concentrations measured by the same method may act as 'surrogate' tumour marker.


   PP6: Examining an alternative formula for calculation of radio-iodine dose in patients of Graves' disease refractory to medical management Top


Ashwini Kalshetty, Sandip Basu, Sharmila Banerjee

Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

Aim: The primary aim of the study is exploratory analysis of a cohort of patients with Graves' disease who are refractory to anti-thyroid medications and have been successfully treated with radioiodine. The secondary objective is to formulate a relatively convenient and user-friendly method for calculation of radioiodine dose in such cases. Materials and Methods: We retrospectively analysed 30 patients with Graves' disease (23 females and 7 males) who had been referred to our centre for radioactive iodine (RAI) therapy. These patients had achieved hypothyroidism post radio-iodine therapy as well as have a minimum follow up of 2 years post-RAI therapy. All patients were previously treated with anti-thyroid medications for a mean period of 3.4 years (range: 0.67-15 years). They were categorised clinically into 3 groups based on their goitre size (as per the WHO goitre grading) as: I (palpable or visible after hyperextension); II (visible in normal position); III (visible from a distance). However, for the mathematical calculation purposes the individual grades were considered as numerical values. All of them underwent radio-iodine uptake (RAIU) and scan after stopping anti-thyroid medications for 4-7 days. The RAIU at 2 hours and 24 hours as well the RAI dose administered were noted. The medical records were analysed and the time to start thyroxine hormone replacement post RAI treatment was noted. Multi-variate regression analysis was performed and the formula for a predictive value (dose in this case) was generated. Other basic data like gender, age at onset of disease were also noted. Results: The mean RAIU at 2 hours and 24 hours was found to be 44.5% and 72.57% respectively. The mean dose administered was 10.61 mCi and all patients had onset of hypothyroidism at a mean duration of 4.4 months post RAI administration. Multivariate regression analysis was performed for prediction of dependent value (dose) by considering goitre grade and RAIU. The formula hence generated was: Dose (mCi)= 14.6 + (0.3xgoitre grade) - (0.07xRAIU). This equation generated nearly equivalent dose in a further simplified form as Dose (mCi)= 15- (0.07xRAIU). Conclusion: This relatively simplistic formula is hereby proposed for quick calculation of RAI dose. It is imperative to undertake further larger trials for validation.


   PP7: Determination of upper reference limit for the measurement of anti-thyroglobulin autoantibodies in complement with serum thyroglobulin in the management of patients with thyroid cancer Top


Chandrakala Sanjay Gholve, Sharmila Banerjee, Savita Kulkarni

Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

Introduction: With the advent of immunometric assays (IMA), thyroglobulin autoantibody (TgAb) measurement has gradually switched from marker of thyroid autoimmunity to a test associated with thyroglobulin (Tg) to verify the presence or absence of TgAb interference in the follow-up of patients with differentiated thyroid cancer (DTC). About 20% of the DTC patients show the presence of TgAb. Despite standardization against the International Reference Preparation MRC 65/93, high inter-method variability, wide variation in detection limits and reference intervals persist. Aim: The main objective of the present study was to determine the upper reference limit for TgAb using commercial anti-Tg immunoassay (Immunotech, France) in combination with the routinely used in-house developed Tg IRMA. Materials and Methods: Thyroid function tests were performed as per the NACB guidelines for 42 healthy, normal volunteers who did not have any thyroid disease. All the volunteers were tested for the presence of TgAb using commercial Immunotech kit. Tg was done using in-house developed IRMA kit. Estimation of the reference limit was based on central 95th percentile intervals, determined in volunteers.Two hundred and eight sera from DTC subjects were also screened for TgAb concentrations. Results: The upper reference range obtained for TgAb was up to 30 IU/ml using the Immunotech kit. With these reference ranges, two control subjects (4.7%) were scored positive for TgAb. Two hundred and eight sera from DTC patients were analyzed for circulating TgAb of which, 28 (16.7 %) showed TgAb concentrations above 30 IU/ml. Conclusion: To enhance the clinical utility, serum TgAb measurement is used as an adjunct test along with serum Tg in DTC patients. Even low TgAb titres have the potential to interfere with Tg measurements. So, in such patients, serial TgAb measurements themselves may serve as a “surrogate” tumor marker. Hence, sensitive and specific TgAb screening of sera is necessary. At RMC, the TgAb test will be used in complement with Tg IRMA assay in the routine management of the DTC patients. Finally, TgAb reference range must be used with caution, taking into account that it is usually set for the diagnosis of autoimmune thyroid disease and not for the identification of potential interference in Tg assay.


   Oral Presentation: Endocrinology Top



   OP1: Clinical outcome of negative Tc-99m MIBI scintigraphy in patients presented with hyperparathyroidism Top


Lokeshwaran Madurai Kalimuthu, Vineet Mishra, Kanishk Markam, Ashutosh Parashar, Manish Ora, Aftab Hasan Nazar, Sanjay Gambhir

Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.

Objective: Aim of this study was to correlate the clinical outcome of the hyper parathyroid (HPTH) patients having positive Tc-99m MIBI scintigraphy. Methods: In this study, we retrospectively evaluated all HPTH patients referred for scan Tc-99m-sesta MIBI parathyroid scintigraphy. It was done as per standard guidelines including flow, blood pool, early, delayed, SPECT/CT and subtraction images of the neck or mediastinum. In all patients with positive scan, detailed biochemical evaluation (intact parathyroid hormone (iPTH), ionized calcium, total serum calcium, serum phosphorus, serum alkaline phosphatase, and vitamin D) were analyzed. All previous anatomical images were also reassessed. Patients follow up information was collected by HIS or telephonically. Results: Out of a total of 94 patients, 61 patients had a positive scan (male-35 and female-26). They had a mean age of 40±14 years, serum iPTH was 18.4± 10 pmol/l, vitamin D was 45.72±2.6 nmol/l, serum calcium was 10.9±1.70 mg/dl, ionized calcium was 1.77±0.8 nmol/l, serum phosphorus was 3.4±1.7 mg/dl and serum alkaline phosphatase was 370±58.6 U/L. 43 patient underwent parathyroidectomy (26 patients underwent focused parathyroidectomy and 17 patients underwent extended parathyroidectomy). Histopathology reports of these patients revealed parathyroid adenoma and parathyroid hyperplasia in 39 and 4 patients respectively. There was 50% fall PTH intraoperatively (IOPTH) in reference to pre excision PTH in all the patients as per modified Miami criteria. All of the patients had normalization of the PTH level in the follow-up. Conclusion: Nowadays, HPTH is detected at marginally raised PTH and calcium. Even at such biochemical levels, Tc-99m-sesta MIBI parathyroid scintigraphy has excellent sensitivity to localize parathyroid pathology. A positive Tc-99m-sesta MIBI parathyroid scintigraphy greatly helps surgeons in deciding surgical approach as well as localizes the pathology.


   Poster Presentation: Endocrinology Top



   PP1: Role of intraoperative probe in radioguided parathyroid surgery Top


Ravneet Kaur1,2, Sarika Sharma1,2, Ashwani Sood 1,2, Bhagwant Rai Mittal1,2

Departments of 1Nuclear Medicine and 2General Surgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

Objective: The purpose of the study was to evaluate same day minimally invasive radio-guided parathyroidectomy using low dose of 99mTc-Sestamibi for removal of single parathyroid adenoma using intraoperative gamma probe. Materials and Methods: Ten patients of mean age 48.3±12.7 years (range 21-65) with clinical diagnosis of hyperparathyroidism were prospectively selected in the present study group. All patients with a median S. PTH 639.9 pg/mL (1st-3rd IQR 127.3 - 1045), mean Ca (12.25±2.68 mg/dl) and dual phase parathyroid imaging with 99mTc-Sestamibi (~20 mCi) for localization of parathyroid adenoma, prior to the surgery. On a separate day, around 2.5 mCi 99mTc-Sestamibi was injected and neck and thorax imaging was done at 10 minutes followed by radio-guided surgery. Counts were taken using gamma probe before, during and after the removal of excised lesion at the surface of neck. Results: Dual phase parathyroid imaging revealed five patients with RIPA, four patients with LIPA and one was negative (though detected by 18F-Choline PET/CT as LIPA). Patients' surgery was performed after low dose sestamibi scan with mean time interval of 101±25.5 minutes (range 60-155) with the help of intraoperative gamma probe. The mean counts to background ratio was 2.60±1.16. After adenomas were removed, ex-vivo counting rate of adenoma confirms the 20% rule. All patients showed more than 50% fall in median PTH levels 30.1 pg/mL (1st-3rd IQR 26.5 - 38) in post-operative period. Conclusion: Intraoperative probe radio-guided surgery seems to be appropriate approach in patients with single parathyroid adenomas with reduced intraoperative time. Low dose of radiotracer resulted in insignificant radiation exposure to the staff.


   PP2: Correlation between imaging characteristics on F18 fluorocholine positron emission tomography computed tomography and biochemical parameters in primary hyper parathyroidism Top


Nikhil Mohan, Meivel Angamuthu, Nishikant Avinash Damle, Chandrasekhar Bal, Madhavi Tripathi, Nikhil Tandon, Rajesh Khadgawat, Chitresh Kumar, Sunil Chumber, Shipra Agarwal

All India Institute of Medical Sciences, New Delhi, India

Aim: To study correlation between imaging characteristics on F18 fluorocholine PET CT and biochemical parameters in primary hyper parathyroidism (PHPT). Materials and Methods: Data of F18 fluorocholine PET CT done for MIBI negative/indeterminate patients with PHPT done between January 2017 to July 2019 in nuclear medicine department of AIIMS New Delhi were reviewed. F18 fluorocholine PET CT was done 45 minutes after i.v injection of 5 mCi of F18 fluorocholine and images were acquired in 64 slice PETCT scanner. Patients with no lesion localization, multiple adenomas, parathyroid hyperplasia (on HPE) were excluded from study. 29 such patients patients who fit the above criterion were analyzed for the size of adenoma on CT, serum calcium and intact parathormone (iPTH) level. We also analyzed the correlation between parathyroid to thyroid uptake with calcium and iPTH levels. Results: Of the 29 patients, 14 were male and 15 were female. Median age of patients was 49 years (range: 10-84 years). Median calcium level was 11.0 mg/dL (range:9.0-15.3 mg/dL) and median parathormone level was 131.0 pg/mL (range:52.6-1466.0 pg/mL). Median lesion size was 8.0 mm (range: 1.6-23.0 mm). Pearson's test showed a significant correlation between serum parathormone level and adenoma size (p=0.017) No significant correlation was seen between serum calcium and adenoma size. Similarly parathyroid to thyroid uptake ratio also was found to correlate with either calcium or iPTH levels. Conclusion: Our retrospective study revealed that only the serum iPTH levels and adenoma size correlated significantly with each other while the calcium levels didn't show any correlation with adenoma size. Parathyroid to thyroid ratio also showed no correlation with either serum calcium or iPTH levels.


   PP3: Clinical outcome of positive Tc-99m MIBI scintigraphy in patients presented with hyperparathyroidism Top


Lokeshwaran Madurai Kalimuthu, Vineet Mishra, Kanishk Markam, Ashutosh Parashar, Manish Ora, Aftab Hasan Nazar, Sanjay Gambhir

Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.

Objective: Aim of this study was to correlate the clinical outcome of the hyper parathyroid (HPTH) patients having positive Tc-99m MIBI scintigraphy. Methods: In this study, we retrospectively evaluated all HPTH patients referred for scan Tc-99m-sesta MIBI parathyroid scintigraphy. It was done as per standard guidelines including flow, blood pool, early, delayed, SPECT/CT and subtraction images of the neck or mediastinum. In all patients with positive scan, detailed biochemical evaluation (intact parathyroid hormone (iPTH), ionized calcium, total serum calcium, serum phosphorus, serum alkaline phosphatase, and vitamin D) were analyzed. All previous anatomical images were also reassessed. Patients follow up information was collected by HIS or telephonically.

Results: Out of a total of 94 patients, 61 patients had a positive scan (male-35 and female-26). They had a mean age of 40±14 years, serum iPTH was 18.4± 10 pmol/l, vitamin D was 45.72±2.6 nmol/l, serum calcium was 10.9±1.70 mg/dl, ionized calcium was 1.77±0.8 nmol/l, serum phosphorus was 3.4±1.7 mg/dl and serum alkaline phosphatase was 370±58.6 U/L. 43 patient underwent parathyroidectomy (26 patients underwent focused parathyroidectomy and 17 patients underwent extended parathyroidectomy). Histopathology reports of these patients revealed parathyroid adenoma and parathyroid hyperplasia in 39 and 4 patients respectively. There was 50% fall PTH intraoperatively (IOPTH) in reference to pre excision PTH in all the patients as per modified Miami criteria. All of the patients had normalization of the PTH level in the follow-up. Conclusion: Nowadays, HPTH is detected at marginally raised PTH and calcium. Even at such biochemical levels, Tc-99m-sesta MIBI parathyroid scintigraphy has excellent sensitivity to localize parathyroid pathology. A positive Tc-99m-sesta MIBI parathyroid scintigraphy greatly helps surgeons in deciding surgical approach as well as localizes the pathology.


   Oral Presentation: Hepatobiliary Top



   OP1: Quantitative 99mTc –sulfur colloid liver SPECT/computed tomography as a noninvasive quantitative technique for liver severity grading in patients with cirrhosis Top


Amritjyot Kaur, Virendra Singh, Shalini Chopra, Ajay Kumar, Arka De, Sunita Kumari, Anish Bhattacharya, Baljinder Singh

Post Graduate Institute of Medical Education and Research, Chandigarh, India.

Background: Quantitative assessment of liver function is critical and essential for patient management and prognosis in chronic liver diseases such as cirrhosis. Indocyanine green clearance, a blood flow dependent technique is a nearby gold standard for functional evaluation of liver function. This test is cumbersome and has other inherent limitations that restrict its application. Dynamic liver function tests that can estimate spatial functional distribution are required especially in case of damaged or cirrhotic liver having functional heterogeneity. In the present study, we have used threshold method and evaluated quantitative 99mTc-sulfur colloid liver SPECT/CT parameters in decompensated cirrhosis for association with clinical severity scores - Child–Turcotte–Pugh (CTP) A, B and C. Materials and Methods: 99mTc-sulfur colloid SPECT/CT was performed on 107 patients with decompensated cirrhosis having variable Child Pugh Score (6-13). Quantitative liver uptake (QLU), quantitative spleen uptake (QSU), liver volume (LV), spleen volume (SV), injected dose/mL of liver (%ID/ml liver) and % injected dose/ml of spleen (%ID/ml of spleen) were calculated. Results: Optimal threshold of 38.0% was calculated using phantom standardisation. For patients with Child Pugh Score Class A (n=22), Class B (n= 62) and Class C (n=21); LV (1086.0±333.0, 971.0±264.0 and 808.0±198.0); SV (585.0±407.0, 674.0±345.0 and 787.0±368); QLU (39.0±8.0, 24.0±7.0 and 15.0±9.0); QSU (22.0±13.0, 31.0±13.0 and 34.0±14.0); %ID/mL of liver (0.039±0.015, 0.026±0.009 and 0.020±0.011) and %ID/mL of spleen (0.047±0.022, 0.05±0.017 and 0.050±0.021 were calculated respectively. Conclusion: Quantitative liver uptake SPECT showed significant correlation with clinical severity Child Pugh Scores and has ability to differentiate severity of disease. Thus, quantitative SPECT of the liver may be an additional, useful, non-invasive quantitative test for assessment of hepatic function and severity of liver disease in cirrhotic patients.


   Oral Presentation: Neurology Top



   OP1: 18F-ML-104 Tau positron emission tomography patterns in amnestic mild cognitive impairment Top


Jasim Jaleel, Madhavi Tripathi, Vivek Baghel, S. T. Arunraj, Praveen Kumar, Aprajit Ballav Dey, Chandrasekhar Bal

All India Institute of Medical Sciences, New Delhi, India.

Aim: Tau positron emission tomography (PET) provides in vivo evidence of neurofibrillary tau tangles in tauopathies including Alzheimer's dementia (AD). We have previously demonstrated increased tau deposition in temporo-parietal regions in AD and early AD in comparison to normal controls (paper in press-Clinical Nuclear Medicine). This study was undertaken to evaluate the tau distribution pattern in patients with amnestic mild cognitive impairment (MCI). Materials and Methods: Thirty-one patients, who were diagnosed clinically as amnestic MCI (MMSE ≥ 24) in the geriatric memory clinic, were included in the study. Each MCI patient underwent 18F-Fluorodeoxyglucose (18F-FDG) PET on the basis of which they were divided into three groups- those showing a metabolic pattern consistent with early AD (ADH- shown to beat a greater risk of developing overt AD), those showing only temporal lobe hypometabolism (TH) and those who did not reveal any metabolic abnormality (N). All patients were taken up for the 18F-ML-104 Tau PET (Neptis-ORA). The tau PET images were independently evaluated using region of interest drawn over bilateral frontal, parietal, medial temporal, lateral temporal lobes, posterior cingulate, precuneus and cerebellum. The standardised uptake value ratios were calculated (SUVregion/SUVcerebellum) and compared in the three groups (based on 18F-FDG PET patterns). Significance was evaluated statistically using Mann Whitney U test. Results: Maximum 18F-ML-104 retention was noted in the medial temporal lobes in all three groups, ADH (mean SUVR-1.65), TH (mean SUVR-1.48) and the N groups (mean SUVR-1.43), with a significant difference between TH and N groups (p=0.03). There was a significant difference in retention of the tracer in the parietal, precuneus (p <0.01) and posterior cingulate (p=0.05) cortex between ADH and N groups. The TH group showed significant difference in retention of the tracer in the medial (p=0.03) and lateral temporal (p=0.01) cortices with the N group and in parietal, precuneus and posterior cingulate with the ADH group. Conclusion: We could demonstrate a significant increase in tau deposition in amnestic MCI patients with a metabolic pattern consistent with early AD on FDG PET. Higher tau binding in the lateral and medial temporal cortices was seen in the TH group, but the absence of significant precuneus and posterior cingulate binding probably suggests that they would not progress to AD. However, the sample size is too small and further evaluation in larger subsets is needed.


   OP2: Comparative performance of 99mTc-TRODAT-1 SPECT/computed tomography and 18F-FDOPA PET/computed tomography imaging in patients with Parkinson disease, Parkinson Plus syndrome and essential tremor Top


Apurva Sood, Bhagwant Rai Mittal, Jaya Shukhla, Ritu Shree1, Manish Modi1

Departments of Nuclear Medicine and 1Neurology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

Aim: The purpose of the present study was to assess the utility of pre-synaptic dopaminergic imaging using 99mTc-TRODAT-1 SPECT/CT and 18F-FDOPA PET/CT and compare their performance in Parkinson disease (PD), Parkinson plus syndrome (PPS) and Essential tremor (ET). Materials and Methods: A total 103 patients; 48 PD (M:F=33:13, age 61 (48-78 yrs), 19 PPS (M:F=10:5, age: 64 (52-76 yrs) and 36 ET (M:F=17:18, age 63 (46-80 yrs) were enrolled prospectively. Hoehn and Yahr staging (HnY) and MDS-UPDRS was done for both PD and PPS. 99mTc-TRODAT-1 SPECT/CT and 18F-FDOPA PET/CT brain scan was done within a week. The scans were analyzed visually and semi-quantitively. Average pixel count (APC) and SUVmean of the striatum was calculated in SPECT and PET images respectively to calculated the specific uptake ratio of striatum (SURs) (SURs= Striatal ROI -Occipital ROI/ Occipital ROI). Comparison of scan findings and SURs values among different groups and correlation between MDS-UPDRS score and HnY was done. Results: Symmetrical comma shaped uptake was seen in bilateral striatum in ET patients with average SURs (avgSURs) of 0.59 (0.49-0.69) on SPECT and 2 (1.73-2.42) on PET images. Reduced uptake in putamen/putamen and caudate was seen in 45/48 cases of PD and 18/19 cases of PPS. Normal striatal uptake was seen in 3 cases of PD [HnY I (n=1) and II (n=2)] on 18F-FDOPA and 1 case of PD (HnY stage I) on 99mTc- TRODAT-1 images. 1 case of PPS (HnY II) showed normal scan on both SPECT and PET images. AvgSURs in PD[ 99mTc-TRODAT-1: 0.30 (0.22-0.40);18F-FDOPA: 1 (0.83-1.29)] and PPS [99mTc-TRODAT-1:0.22 (0.19-0.34);18F-FDOPA:1 (0.65-1.29)] cases was significantly lower than ET cases (p<0.001). No significant difference was found between PD and PPS cases both on SPECT (p=0.17) and PET (p=0.61). ET cases revealed significantly higher average SURs values than early PD cases [HnY I and II (n= 37)] (p= <0.001). Substantial agreement[Weighted Kappa-0.659 (95% CI–0.035-1.00)] was found between 99mTc-TRODAT-1 and 18F-FDOPA for detection of presynaptic-dopaminergic dysfunction. Linear regression showed statistically significant correlation between SPECT and PET modalities for SURs (r=0.67; p<0.01). A negative and significant correlation was found between the contralateral SURs and HnY and MDS-UPDRS score. Conclusion: The present study showed substantial agreement among 99mTc-TRODAT-1 SPECT/CT and 18F-FDOPA PET/CT imaging for evaluation of dopaminergic dysfunction. Both modalities proved to be potential imaging biomarker which can help in differentiation of early PD/PD and PPS from ET patients, but failed to differentiate PD and PPS from each other. 99mTc-TRODAT-1 SPECT/CT using a conventional gamma camera is an appropriate cost-effective modality in evaluation of cases of ET, PD and PPS.


   OP3: Role of inter-ictal F-18 FDG positron emission tomography computed tomographyin refractory epilepsy for localisation of epileptogenic zone in comparison with VEEG and MRI: Impact on surgical decision making Top


Punam Bhoge1,2, Shwetal Pawar1,2

Departments of 1Nuclear Medicine and 2Neurosurgery, Seth G. S. Medical College and KEM Hospital, Mumbai, Maharashtra, India.

Objective: Pre-surgical evaluation of patients of epilepsy includes VEEG, MRI, and interictal PET investigations for exact localization of seizure focus. The study was aimed to understand the role of interictal PET in localizing seizure focus and its impact in surgical decision making. Materials and Methods: 79 patients of drug refractory epilepsy underwent ictal VEEG, MRI and F-18 FDG PET (after injection of 2-3 MBq/Kg of F-18 FDG) during Jan'17 to July'19. Data was analyzed for concordance and discordance between PET and other two investigations to locate focus of epilepsy. Kappa Agreement Test was applied to the available data to look for agreement between two raters. Results: Study included 79 patients with mean age of 22.3 yrs. Concordance of PET with VEEG in 44%, Concordance of PET with MRI in 23.33%, Concordance of MRI with VEEG in 33%. As compared to MRI, overall PET showed additional findings in 53.33%. In Patients having inconclusive MRI (30 %), amongst them PET shows additional findings in 20% patients. Hemispheric involvement in PET is noted in 11%. There is fair agreement between PET and MRI (Kappa Value: 0.478) whereas good agreement between VEEG and PET (Kappa Value: 0.659) Conclusion: In patients of refractory epilepsy, when non-concurrence between MRI and VEEG was seen, PET shows better agreement with VEEG than MRI. PET significantly guided selection of non-operable patients by showing additional hypometabolic areas.


   OP4: Comparison of Tc- 99m ECD interictal and ictal SPECT and subtraction ictal SPECT co-registered to interictal brain SPECT (SISCOS) in preoperative evaluation of drug refractory epilepsy patients Top


S. T. Arun Raj, Angel Hemrom, Madhavi Tripathi, Manjari Tripathi, Dikhra Khan, Sambit Sagar, Arunav Kumar, Jasim Jaleel, Nishikant Damle, Shamim A. Shamim, Chandra Sekhar Bal

All India Institute of Medical Sciences, New Delhi, India.

Aim: Surgical management of drug refractory epilepsy (DRE) require effective localization of the seizure focus. Various investigations like video EEG (VEEG), MRI, and semiology evaluation, are used to generate an effective hypothesis regarding localization f the seizure focus. Brain perfusion imaging during ictal and interictal states and SISCOM are used as a functional imaging modalities to localize the seizure focus. We compared the localization rates for ictal and interictal SPECT studies and SISCOS in DRE patients evaluated in our department. Materials and Methods: Two hundred and seven patients who underwent preoperative workup at All India Institute of Medical Sciences, New Delhi, using ictal, interictal perfusion SPECT and SISCOS between may 2018 and july 2019 were evaluated. For ictal study patients were closely monitored in the epilepsy monitoring unit where they were admitted for vEEG and 99m-Tc ECD was injected within 10 seconds of seizure onset. Results: Median age of the patients were 19 (range 0.4-55 years) with male: female = 131:76. Hemispheric hypoperfusion /fixed defects were seen in 20/207 patients. In 20 patients with hemispheric perfusion defect, SISCOS localized seizure focus in 13 patients (65%) while visual assessment of ictal and inter ictal SPECT could localize only in 10 patients. In the remaining 187 patients SISCOS was able to localize seizure focus in 129/187 (69%) patients while combined inter ictal and ictal SPECT visual assessment was able to localize only in 105/187 patients (56%). Concordance of visual assessment of combined inter ictal and ictal SPECT vs SISCOs was 81% (105/129) with a moderate agreement between the two (k= 0.58). Additional findings of crossed cerebellar diaschisis was present in 18 patients. Conclusion: SISCOS has highest yield and should be incorporated along with visual perfusion SPECT interpretation.


   Poster Presentation: Neurology Top



   PP1: 18F FDG positron emission tomography computed tomography based evaluation of brain parenchymal involvement in patients with corticobasal degeneration Top


Sai Krishnaja Reddy Kanala, Tekchand Kalawat

Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India

Aim: To study the extent and severity of brain hypometabolism in patients with CBD on 18 F FDG PET CT. Objectives: 1] To assess the frequently affected brain hemisphere in patients with CBD. 2] To evaluate the severely involved sites and to calculate the mean Z-Score value for hypometabolism in each lobe. Materials and Methods: This is a semiquantitative retrospective observational study done in all the patients who are suspected to have CBD clinically and in whom 18F FDG PET CT was done, during the period of 2015 to July 2019. Later, modality to model coregistration software, Scenium was used to interpret the metabolism of different regions, and these images were compared to standard model. The standard deviations thus obtained were tabulated as Z scores. Hypom etabolism of a region is defined as uptake less than 2 SD (standard deviation) compared to model. Total 5 regions were studied in the current study, which includes frontal, parietal, temporal, occipital lobes and basal ganglia. Mean Z scores were calculated from these areas and severity of involvement was interpreted as mild, moderate and severe. (Mild: -2 to -3, Moderate: -3 to -4, Severe: >-4). Results: Out of the 14 patients included in the study, 11 were females and 3 were male patients. The mean age of the patients was 60.3 years. (Range: 47 – 75 yrs). - Using Z-score data from scenium software, it was observed that both right (7/14 patients) and left hemispheres (7/14 patients) were equally involved with no single side predominance. - Out of 7 patients with predominantly left hemispheric involvement, Frontal, parietal and temporal regions are commonly involved with severe hypometabolism with relative sparing of Occipital region. Basal ganglia show severe hypometabolism in 2/7 patients with a mean Z- score of -2.78. Similar results were seen in patients with predominant right hemispheric involvement. Conclusion: Asymmetrical hypometabolism of frontal, parietal and temporal lobes with relative sparing of occipital lobes, after exclusion of other corticobasal syndromes, points towards a possible etiological diagnosis of CBD.


 Parkinsonism More Details">   PP2: Evaluation of 99mTc-TRODAT SPECT in the first year of onset of Parkinsonism Top


Sambit Sagar, Kritin Shankar, S. T. Arun Raj, Madhavi Tripathi, Vinay Goyal, Nishikant Damle, Shamim Ahmed Shamim, Poonam, Navin, C. S. Bal

All India Institute of Medical Sciences, Delhi, India.

Aim: 99mTc-TRODAT, which binds to the presynaptic dopamine transporter, could be used to image the dopaminergic system in Parkinson's disease (PD). We evaluated the diagnostic accuracy of 99mTcTRODAT SPECT to evaluate presynaptic dopaminergic dysfunction (PSDD) in patients presenting with parkinsonian symptoms of less than one year duration. Methods: Fifty-nine patients with parkinsonism of less than one year duration were included in this retrospective analysis. All patients had been referred from the movement disorder clinic after work-up and 99mTc-TRODAT Brain SPECT/CT (TS) was done to confirm PSDD. Unilateral or bilateral putaminal decrease was taken as evidence of PSDD while symmetrical tracer uptake in both basal ganglia ruled out Parkinsons. The results of TS were compared to the clinical diagnosis of PD and the use of dopa agonists. Results: Decrease of striatal 99mTc-TRODAT binding was seen in 34 patients while normal binding was noted in 25. 27 of the 34 with PSDD were clinically diagnosed as PD while 5 of the patients with normal TS were diagnosed as PD. Overall sensitivity and specificity of TS was found to be 84.38% (95%CI= 67.21% to 94.72%) and 74.07% (95% CI=53.72% to 88.89%) respectively. Positive predictive value (PPV), negative predictive value (NPV) and accuracy were 79.41% (66.71% to 88.13%), 80.00% (63.43% to 90.22%) and 79.66% (67.17% to 89.02%) respectively. Seven patients had evidence of PSDD however clinically they were kept on follow up without medication. Though the specificity of TS was sub-optimal, clinical diagnosis is equally difficult early in the disease course. In-fact previous studies have shown a low accuracy (~50%) of clinical diagnosis in patients with early parkinsonism (<5 years) (1). Conclusion: 99mTc-TRODAT SPECT is a useful investigation to confirm PSDD within the first year of onset of Parkinsonism. A close follow up of patients with false positive TS would be useful to predict disease evolution over time.


   PP3: Quantitative analysis of 99m Tc-ECD brain perfusion scintigraphy in Moya Moya disease: Our institute experience Top


R. Gopinath, S. Dinesh Kumar, Raman Kumar Joshi, Sridhar Goud, Pradeep Kumar, Chandana, Rose Dawn Bharath

National Institute of Mental Health & Neuro Sciences (NIMHANS), Bengaluru, Karnataka, India.

Aim: To quantitative analyze the Tc99m SPECT baseline and acetazolamide (ACZ) challenge scintigraphy in Moya Moya disease patients using two different commercially available processing software's. Materials and Methods: Retrospective analysis of two sets of images of SPECT CT (baseline & postACZ brain scan) of patients with Moya Moya disease were quantitatively analyzed using PHILIPS ISP&OASIS software. We analyzed 15 cases (n=15) out of that 11 were males and 4 were female patients. Of the fifteen patients one patient data was excluded since it was not able to process on the Oasis software. All the patients were injected 99mTc ECD intravenously a dose of 150 μCi/kg for children and 20 mCi for adult. The images were acquired 45 min post injection. The following acquisition parameters were used in 64 projection for 360 degree, each projection 30 Sec, matrix128*128, zoom 1.0 and 10% window 140 KeV (Tc99m). CT brain was acquired for attenuation correction purpose. The reconstructed images on both baseline and post ACZ were processed in PHILIPS ISP &OASIS software. Since both these software's use different methodology, different quantitative parameters were derived. We compared the results obtained by the two different software's. Results: We compared both software values (baseline & Post ACZ).PHILIPS ISP software given values based on perfusion of each lobe and counts based values. We can calculate % of change in perfusion in each lobe in baseline and post ACZ challenge. OASIS software gives value 3D process, based on automatic elastic transformation into stereotactic  Atlas More Details (talarich) this value is based normal database. Conclusion: Split function study (R/L ratio & L/R ratio) calculated from ISP software (e.g.Moya Moya) gives a more valid result for patient management. However, 3D and Talairach based processing by OASIS software would help accurately value & can be useful for follow up cases.


   PP4: Clinical utility of FDOPA positron emission tomography computed tomography in differential diagnoses of Parkinsonism Top


Meenu Mohan, Dinesh G. Kumar, Shreyas Kudachi, Sachin Arora, Vishnu Hari, Pankaj Kumar, Karuna Luthra, Vikram R. Lele

Department of Nuclear Medicine and PET/CT, Jaslok Hospital and Research Centre, Mumbai, Maharashtra, India.

Aim: In the early stage of the disease, it is difficult to diagnose Idiopathic Parkinson's disease (IPD) as clinical signs may be subtle or can be confused with other parkinsonism related disorders such as multisystem atrophy, corticobasal degeneration and progressive supranuclear palsy. Recent advancements in 18F-DOPA PET/CT imaging reveals different patterns of striatal dopaminergic deficit in Parkinsonian disorders, which may help differentiate these conditions. Our aim was to evaluate the diagnostic utility of F-DOPA PET in differential diagnoses of Parkinsonism and to find out the correlation between F-DOPA uptake in striatum and clinical severity of PD. Materials and Methods: 18F-DOPA PET/CT was performed in patients with Parkinsonism referred to our centre by movement disorder specialists. Patients will be categorised based on Hoehn and Yahr stage. Both qualitative and semiquantitative analyses of the scans were performed. Qualitative interpretation - 18F-DOPA binding values are measured visually in caudate nucleus and putamen. It is a visual analysis and scan is reported as mild, moderate and severe dopaminergic deficit in striatum depending on the severity of the disease. Semiquantitative interpretation is based on region of interest analysis of the caudate nucleus, putamen and occipital cortex. Striatal to occipital ratio (SOR) and sub-regional ratio of striatal to occipital ratio (RSOR) was calculated. Patients will be categorised based on Hoehn and Yahr stage. 18F-DOPA PET/CT diagnoses assigned at the time of imaging was compared with the final clinical diagnoses made by movement specialists after 3 months follow up. Results: In our study out of 50 cases 16 scans were normal. Of the 34 abnormal scans, findings were consistent with IPD in 25 patients and Atypical Parkinson's in the remaining patients. Conclusion: 18F-DOPA PET/CT may help differentiate between IPD, PSP, MSA and CBD among patients presenting with parkinsonian symptoms, which is important for patient counselling and making early decisions about treatment.


   PP5: Epileptogenic zone localization on SISCOS in drug refractory epilepsy Top


Dikhra Khan, S. T. Arun Raj, Madhavi Tripathi, Manjari Tripathi, Ramesh Doddamani, Sarat P. Chandra, Ajay Garg, Chitra Sarkar, Nishikant Damle, C. S. Bal

All India Institute of Medical Sciences, New Delhi, India.

Aim: Drug refractory epilepsy (DRE) can be effectively treated by surgical resection of the epileptogenic zone (EZ) if it is correctly localized. The pre-surgical work-up of such patients includes interictal and ictal SPECT followed by SISCOS (subtraction ictal spect coregistered to SPECT). We have been routinely performing SISCOS for our DRE patients. In this retrospective analysis we determined the concordance of SISCOS for localization of the EZ in DRE patients who underwent surgery. Patients and Methods: This retrospective analysis was conducted in 79 patients of DRE who underwent presurgical workup followed by surgical resection at All India Institute of Medical Sciences, New Delhi. During workup vEEG, MRI, FDG PET/CT and SISCOS was done for all these patients. The concordance of these modalities for localization of the EZ was compared with the reference standard which was surgical resection/biopsy and assessed along with post surgical outcomes (ILAE surgical outcome scales). Results: Age range of patients was 1.7 to 51 years; there were 50 male and 29 females. Seizure onset was during the first decade of life in 51 patients, with a mean duration of symptoms of 9.3+ 6 years. There were 32 temporal lobe epilepsy, 23 cases of extratemporal epilepsy and 24 cases with other causes of epilepsy. FCD (n=32) was the most common histopathological diagnosis in the resected samples. Concordance for localization of the EZ on MRI, vEEG, FDG-PET, and SISCOS was 84%, 59.5%, 54.4% and 87% with the surgically resected EZ. Concordance of SISCOS with MRI, VEEG, and FDG PET for lesion detection was 80%, 65% and 90.1%. Thus SISCOS had highest concordance with FDG-PET. Good surgical outcomes (ILAE scale; Grade 1) were seen in 58% of the patients with localization on SISCOS. Localization of the EZ for SISCOM (subtraction ictal spect coregistered to MRI) has been reported as 88.2% (1) while one study in literature has similar results for SISCOS 87% (2). Conclusion: Localization of the EZ by SISCOS was the highest of all modalities used in pre-surgical evaluation of DRE. This is comparable to the localization of EZ by SISCOM and can therefore be effectively used for on DRE patients.


   PP6: Comparison of dopamine transporter availability in male patients with clinical alcohol dependence by 99m Tc TRODAT scan Top


Anurag Jain, Harkirat Singh

Southern Command Hospital, Pune, Maharashtra, India.

Aim and Objectives: When something makes a person feel happy, a signal is sent to the Ventral tegmental nucleus from hypothalamus, it travels to the Nucleus accumbens and then to the prefrontal cortex. The hippocampus records the memory of this event. The amygdala then creates a conditioned response, encouraging a person to repeat this behaviour. In repeat users, brain receptors become overwhelmed. Brain responds by flooding dopamine (as compensatory mechanism). As a result, dopamine has less impact on the brains reward centre. More dopamine is needed for the same “high feeling” because the brain has adapted – effect known as tolerance. Now the compulsion takes over, and the pleasure associated with an addictive drug subsides. But the memory of the desired effect and “the wanting” persists. The striatal dopamine transporter levels would be decreased in alcohol addiction owing to their down regulation resulting from increased uptake by dopamine at the post synaptic dopaminergic receptors (DAT) in the reward centre. DAT receptor imaging at diagnosis intends to measure the striatal dopamine transporter activity (DAT) in alcohol dependence patients using 99mTc TRODAT. Materials and Methods: We undertook this prospective study in 06 patients with clinical diagnosis of alcohol dependence by treating psychiatrist. These patients underwent 99m Tc-TRODAT-1 SPECT in our department. SPECT images were acquired 4 h after intravenous injection of 08-10 mCi of Tc-99m TRODAT, followed by acquisition on Symbia T6 dual-head Gamma camera (Siemens). Axial, HLA and VLA images were visually interpreted by two different Nuclear Medicine Physicians individually. Consensus was sought where interpretations differed. The results were compared with the clinical alcohol dependence based on Mental state and neurocognitive function examination carried out by psychiatrist Results: A concordant result between Clinical Alcohol dependence and reduction in striatal uptake was obtained in 06/06 patients (100%). Conclusion: Our study suggested that DAT availability is associated with neurocognitive function, and incongruent reduction of DAT may play a pathophysiological role in different subgroups of AD. In addition, decreased DAT availability may be associated with the severity of depressive symptoms in patients with AD. Reductions in dopamine transporter availability may play a pathophysiological role in the development of pure alcohol dependence, given its association with neurocognitive deficits.


   PP7: Role of ictal and inter-ictal Tc-99m ECD brain single-photon emission computed tomography in medically refractory epilepsy patients undergoing surgery and its correlation with magnetic resonance imaging and VEEG findings and post-surgery outcome Top


Arnaaz Maldar, Shwetal Pawar, Sangeeta Ravat, Punam Bhoge

Departments of Nuclear Medicine and Neurology, Seth G.S. Medical College and KEM Hospital, Mumbai, Maharashtra, India.

Aim: Role of ictal and inter-ictal Tc-99m ECD Brain SPECT in medically refractory epilepsy patients undergoing surgery and its correlation with MRI and VEEG findings and post-surgery outcome. Materials and Methods: 38 patients of drug refractory epilepsy with discordant VEEG and MRI findings who had pre-surgical Ictal and inter-ictal SPECT scan done (after injection of 20 mCi of Tc 99m ECD) and later underwent surgery were selected. SPECT findings were correlated with MRI and VEEG findings and post surgical outcome. Results: Correlating with VEEG; in 7 cases (18.4%) SPECT showed better focus lateralization where VEEG showed B/L findings, in 23 cases (60.5%) findings matched, in 4 cases (10.5%) findings mismatched and in 4 cases (10.5%) SPECT could not localize focus. Correlating with MRI; in 9 cases (23.6%) SPECT showed better focus lateralization where MRI showed B/L findings, in 18 cases (47.3%) findings matched, in 6 cases (15.7%) findings mismatched and in 5 cases (13.1%) SPECT could not localize focus. Ictal SPECT showed correlation with VEEG (p-0.006) and with MRI (p-0.02). 34/38 cases (89.5%) had complete seizure freedom post-op. Ictal SPECT guided surgical decision making in 23/38 (60.5%) cases. Conclusion: SPECT showed significant correlation with MRI and VEEG findings. SPECT was more useful for guiding focus localization when VEEG/MRI showed bilateral findings. Post surgical seizure freedom showed good correlation with SPECT.


   PP8: Metabolic characterization of nonpara-neoplastic autoimmune encephalitis Top


Arun Ravi John, A. G. Pandit, Abhinav Jaimini, M. G. Vishnoi

Army Hospital Research and Referral, New Delhi, India.

Aim: To understand the metabolic topography in non paraneoplastic autoimmune encephalitis. Materials and Methods: We retrospectively analysed suspected case of autoimmune encepahilitis referred to our department for ruling out a paraneoplastic aetiology using an 18F-FDG PET-CT. The cases with a detected paraneoplastic cause were excluded. We analysed the metabolic pattern of 5 cases of antibody positive non paraneoplastic autoimmune encephalitis (3 anti NMDA, 1 anti GABAb and 1 anti LGI-1). The visual analysis was complemented by statistical parametric mapping. Results: Cases of non paraneoplastic Anti NMDA receptor encephalitis revealed hypometabolism in the parieto-occipital cortex whereas the case of anti LGI-1 receptor encephalitis revealed extensive fronto-parietal hypometabolism. The case of anti GABAb revealed asymmetric hypermetabolism in the temporal cortex. Conclusion: 18F-FDG PET-CT is therefore useful for metabolic characterisation of non paraneoplastic autoimmune encephalitis and for ruling out a paraneoplastic aetiology in suspected cases of autoimmune encephalitis.


   PP9: Sensitivity and specificity of 18F-dopa pet in movement disorders Top


Naveen Jose Moolan, Shyma Basheer

Amrita Institute of Medical Sciences, Kochi, Kerala, India.

Background and Objectives: The diagnosis at early stage of Parkinson's disease in movement disorders is clinically difficult. So there is a need for functional imaging targeting the pathophysiology of the disease process. 18F-DOPA L-6-[18F] fluoro-3,4-dihydroxyphenylalnine (18F-DOPA) is a positron emission tomography (PET) agent that measures the uptake of dopamine precursors for assessment of presynaptic dopaminergic integrity and has been shown to accurately reflect the monoaminergic disturbances in PD. Methods: A retrospective review of the data at Amrita Institute of Medical Sciences from July 2017 to July 2019 was conducted. The patients medical records were then assessed for length of follow-up, response to levodopa, clinical course of illness, and laterality of symptoms at time of 18F-DOPA PET. The eventual diagnosis by the referring neurologist, movement disorder specialist, was used as the reference standard for further analysis. Results: Of the 25 scans, we found that one was a false negative, 18 were true positives, and 6 were true negatives. The resultant values are Sensitivity 94.74 %, Specificity 100%. Conclusion: In clinically challenging cases, 18F-DOPA PET is very accurate for differentiating PD from other movement disorders in selected cases. So functional imaging by 18F-DOPA PET is useful in early stage of Parkinson's disease.


   PP10: 99mTc TRODAT scintigraphy in the diagnosis of early Parkinson's disease in patients with extrapyramidal symptoms Top


Parvathy Pavithran, H. Vijay Harish

Amrita Institute of Medical Sciences, Kochi, Kerala, India.

Background: Parkinson's disease is a progressive neurodegenerative disorder which affects the dopaminergic neurotransmission. There occurs idiopathic degeneration of dopamine-producing cells in the substantia Nigra, located in the midbrain. The diagnosis is usually based on clinical criteria, which however gives only a probable diagnosis. In this prospective study we evaluated whether 99m Tc TRODAT brain SPECTCT helps in detection of early Parkinson's disease. Methods: 74 clinically suspected cases of early Parkinson's disease were enrolled in this study. After clinical examination by neurologist, 25 mCi of 99mTc TRODAT was injected intravenously. Immediate whole body scan and 3 hours later Brain SPECT CT images were acquired using GE Infinia Hawkeye dual head gamma camera with low energy high resolution collimators. Images were processed. Region of interest were manually drawn using coregistered SPECT and CT images, the ROIs were placed over both striatum, putamen, caudate nucleus. Parameters quantified were: i) specific uptake of each striatum, ii) putamen to caudate ratio & iii) asymmetrical index. Region of interest were also drawn over lungs, liver, abdomen and thigh. Counts per pixel of each of these regions were obtained and used for background correction. McNemar test was applied to compare the scan findings with clinical diagnosis, and thus the utility of 99mTc TRODAT scan in early detection of Parkinson's disease was evaluated. Further analysis of data were performed using appropriate statistical tests. Results: Based on the Modified H & Y staging, patients were clinically classified into Stage 0, I & II. On Analysis; the values of specific uptake of ipsilateral striatum, contralateral striatum were decreasing with disease progression, where as asymmetric index and abdominal counts per pixel values are increasing with disease progression. Conclusion: The findings indicate 99m Tc TRODAT scan can detect Early PD.


   Poster Presentation: Infection, Inflammation and Musculoskeletal Top



   PP1: Preliminary experience of in-housed radiolabeled Tc-99m voriconazole for imaging fungal infections in patients Top


Rakhee Vatsa, Jaya Shukla, Kanchan Palarwal, Anupriya Chhabra, Bhagwant Rai Mittal

Department of Nuclear Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

Aim: Immune compromised patients are very susceptible to invasive fungal infections. Rapid and accurate diagnosis of such infection is hampered by limited diagnostic techniques. Histopathology and cell culture, which are invasive in nature still remains the gold standard for detection of fungal infections. The present study shares the preliminary experience of imaging fungal infection in patients using in-house radiolabeled Tc-99m Voriconazole. Materials and Methods: Commercially available voriconazole was used for in-house radiolabeling with Tc-99m via stannous reduction method. Radiochemical purity was determined by ITLC using saline and acetone mobile phase. Specificity of Tc-99m voriconazole was tested via in-vitro uptake studies in E coli and Aspergillus fumigatus strains. Imaging was performed in a total of 5 patients at 1 hr, 2 hrs and 3hrs post intravenous administration of 5-10 mCi of Tc-99m Voriconazole. Results: Greater than 98% radiolabeling yield was achieved by incubating 500 μg of voriconazole with 10-15 mCi Tc-99m and SnCl2 at acidic reaction pH at room temperature. Rf in saline and acetone was observed to be 0.7–0.8 and 0.0, respectively. In bacterial and fungal cells 3% and 30% binding was observed. Out of 5 patients 1 patient was observed to be positive which was also found positive in culture. Four patients were observed to be negative on Tc-99m voriconazole imaging. One of the 4 patients had tuberculosis and two patients were culture negative. Two patients were already on voriconazole therapy (since 3 months), hence no uptake was observed. Conclusion: Voriconazole was successfully radiolabeled in-house with Tc-99m. The preliminary patient study suggested that Tc-99m Voriconazole has potential to be a diagnostic radiopharmaceutical for non-invasive fungal infection. Further clinical study with more number of patients are under process.


   PP2: Incidentally detected Paget's disease of bone on fluorodeoxyglucose positron emission tomography/computed tomography and its association with serum alkaline phosphatase levels Top


Piyush Chandra, G. Chandran, J. Sangeetha, Indumathi, P. Pooja, Satish Nath

MIOT International, Chennai, Tamil Nadu, India.

Aim: We aimed to test the association between metabolic activity in the Paget's disease of bone and serum alkaline phosphatase levels. Materials and Methods: This was a retrospective analysis of incidentally detected Paget's disease of bone (defined on the basis of characteristic appearance on CT) amongst the 2875 PET/CT's done in our institution from Aug 2016-Aug 2019. Patients with metastatic bone disease were excluded from study. Correlation was determined between SUVmax of Paget's disease and serum alkaline phosphatase (SAP) levels (blood test acquired within a week of PET/CT) and difference in median SUVmax of involved or most active bony lesion (in poly-ostotic disease) in patients with normal and high alkaline phosphatase (high defined as >120 IU/L) using Mann-Whitney U test. Results: Paget's disease of bone was incidentally identified in the 1.2% of the (n=37) patients, of which 73% (n=27) (mean age- 70.2 years, range 51-96, males- 20, and females 7) had documented SAP levels (44% with SAP>120 IU/L) were included in analysis. Commonest site of bone involvement on PET/CT was pelvis (51%) followed by vertebrae (29%), humerus (7%), femur (3%), tibia (3%) and scapula (3%). 78% patients had mono-ostotic and 22% patients had poly-ostotic disease. Median SAP was 92 IU/L and 164 IU/L in mono-ostotic disease and poly-ostic disease respectively. 74% of patients had FDG avid (SUVmax> 3) bone lesions (Mean SUVmax 7.03, range 3.89- 15.17) and 26% of patients had non-FDG avid disease (Mean SUVmax- 1.79, range 1.3-2.7). There was a positive but weak correlation between SUVmax of the hottest bone lesions and SAP levels (R-0.33, p- 0.55). Median SUVmax of the bone lesions was significantly higher in patients with high SAP compared to patients with normal SAP (6.2 Vs 2.7 respectively, p-0.004). Conclusion: Metabolic activity in Paget's disease of bone evaluated with FDG PET/CT correlates with high bone turnover. Further, the results of this study have following clinical implications: 1) Active Paget's disease with high FDG avidity should be recognized a possible false positive finding in metastatic work up of patients with elevated SAP. 2) As active phase of Paget's disease show high FDG avidity, utility of PET/CT in detecting sites of sarcomatous transformation appears to be limited. 3) FDG PET/CT could probably be useful in monitoring response of Paget's disease to bisphosphonates treatment.


   PP3: In vivo assessment of anti-tuberculous drug delivery in patients with tuberculous lymphadenitis by 99m technetium ethambutol scintigraphy Top


Sneha Prakash, Nishikant Avinash Damle, C. S. Bal, Geetanjali Arora, Satyam Srivastava

All India Institute of Medical Sciences, New Delhi, India.

Aim: India has the highest number TB cases worldwide and a robust tuberculosis control program which involves treatment with anti-tubercular drugs for 6-24 months. It is difficult to predict non-responders at the time of initiating therapy. In this pilot study, we aim to assess the 99mTechnetium (Tc) Ethambutol (EMB) uptake in known tuberculous lesions with a theranostic intent. Materials and Methods: 7 patients with known tuberculous lymphadenitis were recruited in the study and were injected 10-20 mCi of 99mTc-labelled antibiotic (Ethambutol) and serial anterior and posterior whole-body scans on a dual head gamma camera were acquired. The scans were acquired as 15 min dynamic and 1 h, 2 h, 4 h and 8 h. SPECT/CT was acquired between 1-2 hours. The uptake detected in the lesions was assessed visually and compared to the uptake in liver. Results: 7 patients with known tuberculous lymphadenitis were assessed out of which 3 were females and 4 were males. The age range was 20-67 years with a median age of 26 years. 2 patients had only cervical lymphadenopathy, 1 patient had cervical as well as axillary lymphadenopathy and 1 patient had cervical, mediastinal and abdominal lymphadenopathy. 2 patients had only mediastinal lymphadenopathy. 1 patient had mediastinal and abdominal lymphadenopathy. In addition to the known nodal sites, 3 patients also had involvement of lungs, intestines and soft tissue. Among these 7 patients, we could identify regional lymphadenopathy in 5 patients. In all 5 patients we could identify 1 regional lymphadenopathy each (4 cervical and 1 abdominal). The ratio of the maximum tracer uptake in the lesion to the maximum tracer uptake was calculated and was in the range of 0.6 to 1.1 with the median being 0.8. Two patients with known lymphadenopathy and but negative on 99mTechnetium scintigraphyshowed mild tracer uptake in lungs and in a pre-sternal abscess respectively with corresponding changes on CT. 1 patient with abdominal lymphadenopathy and intestinal involvement which were both noted on the initial 99mTechnetium scintigraphyunderwent another scan after 2 months of anti-tuberculous treatment and showed uptake in the previously noted lesions. Conclusion: 99mTechnetium EMB scintigraphy may be able to help in the assessment of in vivo drug delivery to the intended target sites (viable mycobacteria) in patients with tuberculosis. Since, inhibition of drug uptake is one of the resistance mechanisms displayed by M. tuberculosis the above findings may have theranostic implications in the future.

[TAG:2]PP4: Incremental role of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in clinically suspected osteomyelitis and prosthetic infection and indeterminate for infection on triple phase 99mTc-methylene diphosphonate bone scintigraphy with single-photon emission computed tomography/computed tomography[/TAG:2]

Shamim Ahmed Shamim, Arun Raj, Geetanjali Arora, Sarthak Tripathy, Madhavi Tripathi, Saurabh Arora, Shashwat Somani, Shreya Dutta Gupta, Shah Alam Khan, S. Venkatesan, Chandrasekhar Bal

All India Institute of Medical Sciences, New Delhi, India.

Aim: To assess the role of 18F-FDG PET/CT in suspected osteomyelitis and prosthetic infection; cases of indeterminate infection on 99mTc-MDP bone scintigraphy. Materials and Methods: Patients with clinically suspected osteomyelitis and prosthetic infections were initially assessed by 99mTc-MDP bone scintigraphy for infection. Perfusion phase, blood pool and delayed phase images were analysed. Indeterminate cases, patients having increased radiotracer activity in any of the above phase images with CT findings suspicious for osteomyelitis. Seventeen patients with indeterminate findings underwent regional 18F-FDG PET/CT. 99mTc-MDP bone scintigraphy and FDG PET/CT results were correlated with final diagnosis, which were confirmed by follow up, biochemical, culture and sensitivity and biopsy results. Results: Seventeen patients underwent both the scans, median age of 35 (range 10-74), M:F=8:9. Six patients had implants in situ. FDG PET/CT was positive in 9 (52.5%) and was negative in 8 patients. All the FDG PET/CT patients had finally confirmed to have infection (100%). Among the 8 patients with negative PET/CT scans, for bone infection 2 patients had synovitis and one patient was diagnosed to have fibrous dysplasia, remaining 5 PET/CT negative patients no other definite diagnosis. Conclusion: Regional 18F-FDG PET/CT can be useful to confirm bone and prosthesis related infections in patients with clinically suspected but indeterminate findings on three phase 99mTc-MDP bone scintigraphy.


   PP5: Unusual sites of extraosseous visceral uptake on 99mTc-MDP bone scintigraphy Top


Pramit Kumar, Sanchay Jain, R. Ashok Kumar, S. Abhinav, Vandana K. Dhingra, Manishi L. Narayan

All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India.

Aim: 99mTc-MDP adsorbs onto hydroxyapatite crystals in bones. Visualization of visceral organs on bone scan may be noted on account of various mechanisms of tracer uptake. Analyzing these mechanisms would not only help in improving understanding the pathophysiology of tracer biodistribution but also aid in finding the cause and treating other coexisting pathologies that may change the patient management for better disease outcome. Materials and Methods: Here we report 2 cases where extraosseous visceral uptake of 99mTc-MDP was seen on whole body skeletal scintigraphy. Results: Case 1: A 32 year old female, a post operated case of infiltrating ductal carcinoma of right breast referred for 99mTc- MDP bone scan for metastatic workup. Bone scan showed diffusely increased tracer uptake in the liver parenchyma, spleen and bilateral lungs, in addition to multiple foci of skeletal metastasis. Case 2: A 45-year-old male, known case of osteosarcoma of right femur, underwent bone scan for metastatic work up, that revealed diffusely increased tracer uptake in bilateral lungs and stomach in addition to tracer uptake at primary osseous tumor & multiple skeletal metastatic sites. Diffuse hepatic uptake may be seen when, 99mTc-Sulfur colloid study performed on preceding day, due to improper labeling of radiopharmaceuticals, administration of intravenous iodinated contrast following 99mTc-MDP injection, excess iron (therapy or overload), amyloidosis, severe hepatic necrosis. Diffuse pulmonary and gastric uptake is rare and may be related to local tissue damage, neoplasms, sarcoidosis, and vitamin D intoxication. Patient history, examination, and biochemical findings ruled out these causes in both the cases. Also, other patients who underwent bone scintigraphy on the same days using same MDP preparation, did not show unusual extraosseous uptake. Metastatic and dystrophic calcifications are common causes implicated for extraosseous uptake of 99mTc-MDP. Osteosarcoma metastases produce osteoid matrix which binds with MDP. Diffuse hepatic, pulmonary or gastric uptake of 99mTc-MDP is rare. Lungs and stomach have high intracellular pH, hence predisposed for metastatic calcification. Solubility product of calcium and phosphorus may exceed 60 in hypercalcemia which results in precipitation of calcium in extracellular space. Laboratory findings revealed hypercalcemia in both the patients, and solubility product in case 1 and 2 were 101.76 and 67.95 respectively. Moreover, Blood Urea (166 mg/dl) and Serum Creatinine (3.45 mg/dl) were elevated in Case 2, where chronic renal failure may be an additional contributory cause of hypercalcemia, in addition to hypercalcemia of malignancy resulting in metastatic calcification. Conclusion: In our present series of cases, metastatic calcification is identified as the primary cause for extraosseous visceral uptake of 99mTc-MDP.


   PP6: Panoramic overview of the utility of single-photon emission computed tomography/computed tomography in lymphoscintigraphy – Tailored case by case approach Top


Shema Mathew

Apollo Hospitals, Chennai, Tamil Nadu, India.

Aim: To evaluate the role of SPECT/CT in anatomical delineation in patients undergoing planar lymphoscintigraphy. Materials and Methods: This is a prospective cross-sectional study comprising of 34 patients (19 males and 15 females) referred for lymphoscintigraphy for evaluation of primary/ secondary lymphedema and sentinel lymph node mapping. A single injection of 0.5 mCi of Tc-99m nano albumin is injected intradermally in the 1st inter digital space of bilateral limbs/ peritumorally as applicable. Immediate, post exercise and delayed (3 hrs, 24 hrs if required) images were acquired on Symbia T6 gamma camera, using pixel size of 1024 x 512 with scan rate at 10 cm/mt. SPECT with low dose non diagnostic CT of the region of interest was performed. Results: Of 5/34 cases referred for primary lymphedema, SPECT CT demonstrated ancillary findings of lymphocele, lymph cyst, lymph lake in 3 cases. SPECT CT was also useful in anatomical delineation of lymphangiosarcoma in 2/34 cases. Out of 17/34 (34 limbs) cases referred for secondary lymphedema, 20 limbs showed Grade III, 9 showed Grade II, 5 limbs showed Grade I lymphedema respectively. Incorporation of SPECT/CT proved superior to planar in differentiating superficial and deep inguinal nodes in 14/34 limbs, identifying tracer contamination in 3/34 limbs, upstaging of 2/34 limbs, differentiating popliteal and neo nodes in 2/34 limbs, identifying abdominal back flow in 2/17 cases and gave incidental additional finding of hernia with bladder as content in 1/17 case. Chylothorax and chyloperitoneum identified by planar in 3/34 cases was confirmed and localized with SPECT CT. During mapping of nodes for melanoma, penile, breast and head and neck malignancies, which constituted 7/34 cases, sentinel node was localized by planar imaging and additional information like size, depth from skin and anatomical relations was obtained from SPECT/CT. Overall sensitivity and specificity of planar lymphoscintigraphy was found to be 86 %, 73 % respectively, considering SPECT CT as gold standard. Conclusion: Lymphoscintigraphy is the most reliable and least invasive test available for the evaluation of lymphedema, and a useful tool for sentinel node mapping. Addition of SPECT/CT proved to be superior to planar imaging in providing a clearer picture of the pathophysiology in lymphedema. SPECT/CT proved to be of highest utility in anatomical delineation, exploitation of which will be useful in guiding surgeons for functional reconstruction with selective nodal dissection, minimizing co-morbidity to the patients.


   PP7: Utility of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the initial assessment and for therapeutic response in patients with tuberculosis Top


Apurva Sood, Bhagwant Rai Mittal, Manish Modi1, Rajesh Chhabra2, Roshan Verma3, Ashwin Singh Parihar, Swayamjeet Satapathy, Rajender Kumar

Departments of Nuclear Medicine, 1Neurology, 2Neurosurgery and 3Otolaryngology and Head and Neck Surgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

Aim: The aim of the present study is to assess the utility of F18-FDG PET/CT in initial assessment and therapeutic response in patients with tuberculosis (TB). Materials and Methods: 53 patients (33 men; 20 women; mean age 32.3 years (range 18-64 years) diagnosed with pulmonary TB (n=21) and extrapulmonary TB (n=32) who underwent whole-body F18-FDG PET/CT for initial assessment prior to anti-tubercular therapy (ATT) initiation and a follow up scan 3-4 months after initiation of ATT were included in the study. Visual and semiquantitative (SUVmax) analysis were used for scan assessment of the baseline and follow up scan. Treatment response on interim scans were categorized as Complete metabolic response (CMR:Resolution of all pathologic F18-FDG uptake); Favourable response to therapy (FRT:at least 1 residual site of pathologic F18-FDG uptake with reduction in number and intensity (SUVmax) of lesions); Stable Disease (SD: multiple sites of high F18-FDG uptake with no significant change in number and intensity of the lesions) and Disease progression (DP: increase in the size/ uptake intensity of the lesions and/or appearance of new lesions).CMR, FRT and SD cases were considered as responders and DP cases as non-responders. Treatment response was correlated with clinical outcome (mortality) and ATT duration. Results: Baseline F18-FDG PET/CT were positive in all the patients (100%) and detected additional disease sites other than suspected clinically in 42/53 (79%) patients; in the form of lymphadenopathy, spinal cord, liver, spleen, etc. On interim PET/CT, 9 patients showed CMR, 21 showed FRT, 8 showed SD and 15 showed DP. The percentage decrease in SUVmax in FRT group and SD was 54% (IQR 47-58) and 13% (IQR 11.5-16) respectively. DP was documented in 15 (28%) patients with appearance of new F18-FDG avid lesions in 12 and significant increase (40%; IQR 38-43) in avidity in preexisting lesions in 3 patients. A longer duration of ATT was seen in non-responders (DP-28.5 months (IQR 27 – 31); p=<.001) than responders [FRT- 16 months (IQR 12 – 18); CMR-10 months (IQR 9 – 16); SD 14 months (IQR 10.5 – 17.5)]. During follow up 6/53 patients died, out of which 5 were of DP group and 1 patient belonged to SD. Non-responders showed 40% mortality compared to 2.6% in the responder group (p=<.001). Conclusion: F18-FDG PET/CT is a valuable, non-invasive imaging biomarker for disease mapping and assessing therapeutic response. Treatment response in the interim PET/CT done at 3-4 months predicted the duration of ATT and clinical outcome of the patients.


   PP8: Role of lung aerosol scintigraphy in diabetic patients without any pulmonary symptoms Top


Keerthi Chandra Kota, Nandini Pandit, Dhanapathi Halanaik, Madhusudhanan Ponnusamy

Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.

Introduction and Aim: Diabetes mellitus is one of the most common chronic diseases in the world. Retinopathy, neuropathy, nephropathy, and cardiovascular dysfunction are common diabetic complications and are basically caused by vascular damage. Pulmonary complications of diabetes are frequently disregarded, because of the great micro vascular reserve of alveolar-capillary system. Diabetic related lung complications are related to vascular damage and most of them are sub-clinical. As aerosol clearance from lung is an indirect evaluation of epithelial capillary permeability, in this study, we aim to compare the aerosol clearance in diabetic patients without any pulmonary symptoms with normal population. Materials and Methods: A prospective cross-sectional comparative study. The inclusion criteria include diagnosed cases of diabetes without any pulmonary symptoms and normal population with age between 18-60 years. The exclusion criteria include history of smoking, history of any other known pulmonary or cardiac disorders, history of respiratory tract infections in the past 6 weeks, pregnancy and breastfeeding. Total participants were divided into two groups, diabetic group and non-diabetic group. Lung aerosol scintigraphy was performed in all of them using Tc-99m DTPA aerosols. Participants are subjected to aerosol inhalation for 3 minutes, and 30 minutes dynamic scan was acquired in anterior and posterior views in Siemens dual-headed gamma camera. Time activity curve (TAC) was created by drawing ROI over lung fields and T1/2 for DTPA clearance was calculated by using TAC. Mean T1/2 of two groups were compared using unpaired T test. Results: Total 86 participants were evaluated, 58 (M:F=15:43) were in diabetic group and 28 (M:F=3:25) were in non-diabetic group. Mean (Standard deviation) T1/2 in diabetic group was 55.707 (15.4261) and in non-diabetic group was 47.643 (14.4895). Mean difference is compared using unpaired T test with a 95% confidence interval, which is statistically significant (p<0.05). We also did a subgroup analysis in diabetic population, where we divided them into two subgroups, one with known diabetic complications (N=26, M:F=4:22) and other without any complications (N=32, M:F=11:19). The mean T1/2(standard deviation) of the two subgroups was 61.038 (15.2852) and 51.375 (14.3499) respectively and the mean difference was statistically significant (p<0.05). Conclusion: The significant difference in clearance pattern between diabetic and non-diabetic population suggests impaired permeability in diabetic population, especially in those who already have other diabetic-related complications. With this study, we can assume that lung aerosol scintigraphy can detect the changes in vascular permeability in diabetic patients even before they are symptomatic.


   PP9: Feline aspects of sarcoidosis: Pictural cases Top


Gilles Grimon, Luis Ammour, Malika Chekroun, Léa Gomez, Florent L. Besson, Emmanuel Durand

Department of Biophysics and Nuclear Medicine, Hôpitaux Universitaires Paris-Sud, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France.

Sarcoidosis is a multisystemic disorder characterized by the formation of non-caseating granulomas in various organs. We report two cases of diffuse sarcoidosis mimics feline aspects on 18F-FDG-PET examination: a leopard sign for subcutaneous sarcoidosis, and a tiger sign for a muscular sarcoidosis. Aim of the Study: describe two particular aspects of whole-body 18F-FDG PET/CT examination in sarcoidosis. Materials and Methods: Two patients referred to evaluate the activity of a known sarcoidosis. Results 1: The first patient, a 29-year-old man, presents a systemic sarcoidosis with chest involvement, nasal granulomas and subcutaneous multiple nodules. PET showed extensive intense cutaneous and subcutaneous 18F-FDG micronodular uptakes. Mediastinal nodes also showed intense uptakes together with intense nasal fixation. Histopathology of subcutaneous nodule demonstrated inflammatory infiltrate, epithelioid non-caseating granulomas, nucleated multiple giant cells, some eosinophilic necrosis with apoptotic cells. Discussion 1: The frequency of subcutaneous lesions (Darier-Roussy nodules) is generally rapported between 2 and 6 % of sarcoidosis cases. Subcutaneous sarcoidosis seems associated with the disease activity, although not with the disease severity, and does not help in predicting the prognosis. In our patient, dramatically progression 3 months later despite corticosteroid treatment appears in terms of number and intensity of subcutaneous nodules, mimics a leopard-man appearance. Results 2: The second patient, a 43-year-old woman, was treated 7 months for sarcoidosis (renal involvement, pulmonary lesions of stage II). Corticotherapy has been reduced because of femoral head necrosis. It does not present any noticeable muscular fatigue. PET showed multiple linear muscle hypermetabolic foci predominantly at the root of the limbs, with a rather posterior distribution in the lower limbs. It associates an intense parotids' hypermetabolism, and mediastino-hilar nodes fixations. Discussion 2: Muscular sarcoidosis (0.5 to 5 % of patients) is most frequently chronic atrophic, or nodular. Diffuse acute myopathy type is rare, rarely symptomatic, and difficult to diagnose. Muscle biopsy (not available for this patient) classically showed inflammatory infiltration, muscle fibers size variations, necrosis and regeneration. Positive uptake of Gallium or FDG, echography or MRI inconsistently showed diffuse high signal intensity of inflammation in the skeletal muscle. Involved muscles predominate on the dorsal parts of the lower limb muscles, which is the case in our patient. Linear fixations mimic a tiger-man appearance. Conclusion: Both aspects described are rare. They show peripheral massive sarcoidosis, subcutaneous and muscular. The whole-body produced pictures are not only fun, but specific and useful for the follow-up of the disease.


   PP10: Use of quality indicators at nuclear medicine department Top


Nisha Bhatia, Meenakshi Devri, Saumya Kumari, Sunil Saini1

Departments of Nuclear Medicine and 1Surgical Oncology, Cancer Research Institute, Swami Rama Himalayan University, Dehradun, Uttarakhand, India.

Background and Objectives: Measuring the quality of health care is a necessary step in the process of improving health care quality. Quality of hospital and its departments can be measured by calculating various quality indicators. The aim of present study is to evaluate the different quality indicators which can be implemented to assess the patient's experience and satisfaction level, employee's safety and satisfaction level and check the work quality of nuclear medicine department. Materials and Methods: In the present study authors have listed the various quality indicators classified into three main categories: 1. Patient's satisfaction index is a key quality indicator to assess the patient's experience and satisfaction level which can be calculated by collecting feedback from the patients after completion of the procedure. At our department feedback is collected through patient's feedback forms. Patients & their attendants are asked to fill this form. 2. Quality indicators to assess the employee's safety and satisfaction level are (a) compliance to hand hygiene practice, (b) percentage of adherence to radiation safety precautions by employees while working in department, (c) note incidence to needle stick injury and take immediate action, (d) calculate percentage of employees who are aware and having knowledge about employees responsibilities and welfare schemes, (e) calculate employee satisfaction index, (f) percentage of staff provided pre-exposure prophylaxis (vaccination). 3. Quality of work services at nuclear medicine department can be checked by calculating different quality indicators. These quality indicators includes (a) waiting time for diagnostics, this is time from which patient has come to diagnostic service till the time that the test is initiated, (b) clinical correlation which is a percentage of reports correlating with clinical diagnosis, (c) rate of redose, (d) number of reporting errors, (e) equipment down time. Observations: Patients satisfaction index at nuclear medicine department for last one year was 92.4 %, which is excellent as percentage is more than 75 %. Periodic audits were conducted and found that all employees were following the hand hygiene practice, adhere to radiation safety rules, there was no incidence for needle stick injury in past one year, awareness and knowledge about employee's responsibilities and welfare schemes was at moderate level, all employees were vaccinated for hepatitis B. Average waiting time was 1 hour, 90% reports were correlating with clinical diagnosis, redose rate was 7% and most common reason for redose was extravasation of dose, reporting errors were 1 % due to misprint, inventory of equipment down time was maintained and immediate actions were taken. Conclusion: We suggest that staff education training programs should be organized on regular intervals to educate the staff about importance of hand hygiene, corrective & preventive actions for needle stick injury, radiation safety awareness, spill control and responsibility & rights of employee to ensure the safety of staff while working at nuclear medicine department. We feel that nuclear medicine workers should focus on the importance of these quality indicators, their analysis and use of same for improving the service quality and radiation safety measures for staff, patients and public.


   PP11: Clinical utility of dual-point: Immediate blood pool and standard whole body fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging in evaluating active disease activity in diagnosed rheumatoid arthritis patients Top


Ramesh Rao, Sunita Sonavane, A. G. Rajadhyaksha1, Nitin Sarate1, Biju Menon, Nawab Singh, Ramesh Asopa2

Scintigraphy Section, Radiation Medicine Centre, Bhabha Atomic Research Centre, 1Deptatment of Medicine- Rheumatology, Seth G.S.M.C and K.E.M.H, 2Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

Introduction: Rheumatoid arthritis (RA) is an inflammatory autoimmune disease featuring chronic inflammation of the joints and bone destruction. Clinical manifestations include pain, tenderness and symmetrical swelling of joints and eventually loss of function. To prevent irreversible tissue damage, inflammatory rheumatic disease must be diagnosed and treated in early stage. Targeting the increased glucose uptake of infiltrating granulocytes and tissue macrophages with fluorine-18 fluorodeoxyglucose (FDG). PET/CT have indicated the FDG uptake in affected joints reflecting the disease activity of RA at the molecular level. FDG PET/CT have been clinically used for monitoring the response to treatment by enabling the detailed assessment of disease activity in the involved joints of the whole body. Materials and Methods: The patients diagnosed with rheumatoid arthritis referred by the Rheumatologist, underwent Dual-Point whole body 18F-FDG PET/CT imaging i.e. Immediate Blood Pool and Standard 1 hour post FDG (185 MBq–250 MBq) injection. Patients fasted for approximately 6 h before the injection. Ten patients (all women, mean age 49.6 years) underwent Immediate Blood Pool 18F-FDG (185 MBq–250 MBq) whole body PET/CT imaging from head to toe (Philips Gemini TF16), 2 mins-10 mins post intravenous injection and then underwent Standard whole body PET/CT imaging from head to toe (post 1 hour waiting period post injection of the radiotracer). Images were reconstructed using a 3D row action maximum likelihood algorithm (RAMLA). Attenuation correction was applied using dedicated CT data (CTAC). FDG uptake in the shoulder, elbow, wrist, interphalangeal, hip, sacroiliac joint, knee, ankle and intertarsal joints (total of 70 joints) on both sides were evaluated by visual and semi quantitatively using maximum standardized uptake value (SUVmax) both in the Immediate Blood Pool and Standard imaging. Results: In all ten patients, FDG (SUVmax) uptake was charted in various joints, in both Immediate Blood Pool and Standard technique. The intensity of uptake varied from mild to intense which correlated well with the clinical evaluation of involved joints. Results showed Immediate Blood Pool wholebody scan SUVmax range from 0.15 to 6.44. Higher in SUVmax Immediate Blood Pool ranged from 0.02 to 5.8 compared to standard technique in the involved joints. Conclusion: FDG-PET/CT represents the inflammatory activity in small and large joints in patients with RA. By our pilot study we could delineate immediate blood pool wholebody PET/CT imaging, the involved joints showed relatively higher SUVmax compared to Standard wholebody PET/CT imaging. This can be likely secondary to locoregional hyperemia of the involved joints. However, the number of patients are very small to conclude and need standard case control study to get clinically valid and rationalized results.


   PP12: Pyrexia of unknown origin diagnosed as vasculitis by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography: A case series Top


M. G. Vishnoi, Anurag Jain, Arun Ravi John, K. P. Solanki, B. K. Singh, Rajeev Kumar, Abhishek Mahato, Amit Sharma

Army Hospital (Referral and Research), New Delhi, India.

Introduction: PUO or pyrexia of unknown origin term was first defined by Petersdorf and Beeson in 1961 as FUO, he states an illness of more than 3 weeks' duration with fever higher than 38.3°C (101°F) on several occasions and diagnosis uncertain after 1 week of study in the hospital. This definition was changed multiple time with incorporation of qualitative and quantitative criterias. FDG-PET/CT is a functional imaging technique with a well established role in oncology as well as in inflammatory diseases. FDG-PET is based on the ability to detect increased glucose uptake from high glycolytic activity of inflammatory cells in inflamed arterial walls and synovia/bursa. It can identify the presence of systemic LVV in patients. Here we assess the role of 18F-FDG PET/CT in evaluation of pyrexia of unknown origin (PUO) in a tertiary care hospital. We present here a series of cases of PUO which are diagnosed as large vessels vasculitis with help of FDG PET/CT. Materials and Methods: A prospective observational study conducted at Army hospital (R&R) over the period of 3 year from August 15 to August 18. Study comprise of 100 patients of PUO who were subjected for 18F FDG PET/CT. Results: Here we present a case series of 06 patients [Table 1] diagnosed as large vessels vasculitis on the basis of FDG PET CT advised to find out reason of PUO. Conclusion: Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography is an important modality in the workup of PUO. It supported the final diagnosis in 42% of our patients and there was 6% of patients were diagnosed as large vessels vasculitis. Thus, PET/CT should only be considered routine workup procedure in work up of cases of PUO and in suspected noninfectious inflammatory disorders when diagnostic clues are absent.
Table 1: FDG PET findings in patients with PUO

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   Oral Presentation: Radiation Protection Top



   OP1: Comparison of radiation dose received by radiation worker from automated injector and manual injection during fluorine-18 fluorodeoxyglucose injection process Top


Saumya Srivastava, Subhash Chand Kheruka, Pankaj Tandon1, Sanjay Gambhi

Department of Nuclear Medicine, SGPGIMS, Lucknow, Uttar Pradesh, 1Radiological Safety Division, IATS, AERB, Mumbai, Maharashtra, India.

Aim: The aim of this study was to compare the radiation dose received by radiation worker from automated injector and manual injection during 18F-FDG injection process. Introduction: Significant staff exposure is generally expected during PET-and PET/CT applications. Whole-body doses as well as extremity doses and eyes are usually higher per procedure compared with SPECT applications. Dispensing individual patient doses and manual injection involves high extremity doses even when heavy weighted syringe shields are used. Whole-body doses per procedure are relatively lower compared with extremity doses and are generally spread over the entire procedure (Guillet, B., Quentin, P., Waultier, S., Bourrelly, M., Pisano, P. and Mundler, O. Technologist radiation exposure in routine clinical practice with 18F-FDG PET. J. Nucl. Med. Technol. 33, 175-179 (2005). Optimisation of the individual workload is often used to restrict staff doses, but many PET centres face the need for further optimisation to reduce the staff doses to an acceptable level. During this study the effect of the use of an automated dispensing and injection system for (18)FDG on whole-body doses extremity and eyes doses was evaluated. Materials and Methods: Detailed dosimetric studies using CaSO4:Dy Teflon (TLD) Chest, Ring and head for whole body dose, extremity dose and eye dosimetry were carried out by two methods manual injection & automated injection (IRIS, COMECER, Italy) while dispensing, measuring and during administration by the staff. Results: It is seen that there is an approximately 97% reduction in occupational left hand extremity doses, 98% reduction in occupational right hand extremity doses and 30% reduction in occupational eye-lens doses, where 95% reduction in occupational whole body dose was reported during automated administration of FDG. Conclusion: The study shows that with the use of automated dispensing and injection a more than 95% staff dose reduction can be obtained.


   Poster Presentation: Radiation Protection Top



   PP1: Cross-absorbed dose contribution of 177Lu-DOTATATE in patient specific dosimetry. Yes or not? Top


Ali Ebrahimifard, Hosein Rajabi

Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.

Aim: Determining the contribution of cross-absorbed dose in radionuclide therapy has always been an important subject. In radionuclide therapy, the physiological function of the organs at risk may be altered in multi-cycle therapies. Care must be taken that the dosimetry method which was used for these patients can be important in determining the contribution of this factor. Another factor involved is the change in the effective half-life of the radiopharmaceutical in different cycles. The aim of this study was to evaluate the different factors affecting the 177Lu-DOTATATE cross-absorbed dose in patients with NET tumors. Materials and Methods: We investigated the papers which are considered the dosimetry of 177Lu-DOTATATE based on SPECT/CT. The possible factors which can be considered as the error producer are included: effective radioactive half-life, Time Activity Curve calculation, S value, segmentation methods. Results: In a study which done by Sandstrom, the cross-absorbed dose contribution for kidney, as an OAR, for 500 patients with the sVOI method and assuming a constant rate of kidney function in different cycles and considering the constant effective half-life of radiopharmaceuticals calculated less than %10. In another study, Gotz reported a relative error of 25% in calculating the absorbed dose. They considered the errors included TAC error, S value computational error, and segmentation method error which was been not considered by Sandstrom. In another study by Sandstrom, different segmentation methods including sVOI, aVOI and tVOI were investigated. They have reported that, unlike the spleen, the volume of kidney function decreases over each cycle of treatment. Also, they showed that the sVOI method is more accurate for calculating the cross-absorbed dose. Conclusion: In the light of the presented results and with the consider the high activity of radiopharmaceutical injection for these patients, the decision to consider or not to consider cross-absorbed dose during radionuclide therapy with 177Lu-DOTATATE for organ at risk such as the kidney and taking into account all the factors which have can made a possible error in calculations need further investigation. Any neglecting of the cross-absorbed dose contribution is not permitted and may increase the absorbed dose and damage the healthy tissue. Ultimately, the application of Monte Carlo methods to increase the accuracy of the cross-absorbed dose is suggested.


   PP2: Evaluation of the dosimetry methods accuracy in the different cycles of 177Lu-DOTATATE therapy in patients with neuroendocrine tumors Top


Ali Ebrahimifard, Hosein Rajabi, Shamim Bagheri

Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.

Aim: Patient-specific radiation absorbed dose in radionuclide therapy is a critical subject for 177Lu-DOTATATE treatment. Analytical methods which have widely used are included: the small volume of interest (sVOI), anatomical CT (aVOI) and on thresholds on functional images (tVOI). Renal function changes in the different treatment cycles may cause an error in the accuracy of analytical radiation dosimetry methods. The aim of this work was the comparison of the accuracy of these methods in the different treatment cycles. Materials and Methods: Our study included two patient with neuroendocrine tumors under 177Lu-DOTATATE treatment. The imaging procedure was included: a SPECT/CT imaging 24 h after injection and two SPECT imaging 4 and 7 day after injection. This procedure was repeated for every cycle. sVOI, aVOI and tVOI methods used for absorbed dose calculation. Results: There were no significant difference absorbed dose values between different methods for first cycles. But, in the subsequent cycles, the kidney function was decreased. So, there was a grate different absorbed dose ratio between aVOI and tVOI calculation (more than 12%). This despite the fact that there were no significant differences between absorbed dose values calculated with sVOI and tVOI methods (less than 3%). Conclusion: The decrease in renal function for subsequent treatment cycles can have the main effect on the accuracy of analytical dosimetry methods especially in aVOI method. The absorbed dose values obtained from the tVOI method were most consistent with the decrease in renal function. But the low quality of SPECT images is the main challenging to determine the kidney volume in the tVOI method. Although sVOI and tVOI had same results, we think that there are need to use the more accurate method such as Monte Carlo method for determining the absorbed dose values with considering to kidney functional changing in the during of treatment.


   PP3: Optimization of radiation dose to the patient from computed tomography component of whole-body positron emission tomography/computed tomography Top


Harsimran Kaur, Ankit Watts, Harmandeep Singh, Bhagwant Rai Mittal

Department of Nuclear Medicine, PGIMER, Chandigarh, India.

Aim: To optimally reduce radiation dose from CT by modulating tube current using weight-based protocols. Materials and Methods: A total of 148 patients were included in the study. All patients underwent whole body 18F-FDG-PET/CT on GE DISCOVERY MI-DR LYSO based Time of flight (TOF) PET/CT (GE Healthcare, USA). Patients were categorized broadly into two groups: Below 60 kg & above 60 kg. Further patients below 60 kg were randomly distributed into conventional Protocol 1 (120 kVp, mA 80-350, Noise Index 15.30), New optimized Protocol 2 (140 kVp, mA 80-200, Noise Index 16.83) & Protocol 3 (140 kVp, mA 80-250, Noise Index 16.83). Patients above 60 kg were similarly distributed into conventional Protocol 4 (120 kVp, mA 80-350, Noise Index 15.30) New optimized Protocol 5 (140 kVp, mA 80-200, Noise Index 16.83) & Protocol 6 (140 kVp, mA 80-250, Noise Index 16.83). Radiation Dose estimates were documented by software generated CTDI & DLP values for all the patients. CT image quality was assessed both qualitatively & quantitatively for all the 148 patients. CT axial slice at the level of the first lumbar vertebra was chosen to draw ROI's over abdominal aorta (ROIAA), right psoas muscle (ROIPSM) & measurement of Noise (average of all four corners of the image). Finally, the CNR was calculated based formulae as = (ROIAA– ROIPSM)/Noise. Qualitative assessment was done by reviewing the image quality of CT images at the levels of neck, thorax, and abdomen. Studies were scored blindly by a nuclear medicine physician, on the scale of 1 to 5 taking into account Image contrast, Noise & Artefacts. Results: In Group of <60 kg, significant reduction in CTDI was noted in new Protocol 2 (6.69±1.32 mGy) & Protocol 3 (6.08±0.74 mGy) as compared conventional Protocol 1 (7.94±1.81 mGy). Similarly DLP values also showed similar trends with 641.29±137.03 & 594.13±89.97 mGy-cm noted for Protocol 2 & 3 as compared to 773.38±153.70 mGy-cm. Upon applying t-test the difference was found to be statistically significant (p=0.011 & 0.000 respectively) in both CTDI & DLP values. In group of >60 kg, no statistically significant difference was found in both CTDI & DLP values in protocol 5 (10.59±1.84 mGy) as compared to conventional protocol 4 (11.74±2.45 mGy, p=0.072), while the difference was statistically significant between in protocol 6 (9.29±2.19 mGy) & conventional protocol 4 (p=0.007). Image Quality Results: In Group of <60 kg, image quality parameters (CNR, Noise & IQ scoring) were found to be significantly different in all the protocols. While in-group of >60 kg, Noise & IQ scoring showed no significant difference but CNR had significant difference. Conclusion: Significant reduction in radiation dose was obtained using patient specific body weight-based protocols during whole-body18FDG PET/CT. Mean Image quality scores of all groups were more than 3 indicating interpretable image quality.


   PP4: Occupational exposure of radiation to the health care workers, working in DSA radiology department Top


S. Prabu Titus Devakumar, Sanjay Gambhir, Subash Chand Kheruka, H. K. Singh, Pankaj Tandon, Rajinikant R. Yadav, Kshama Shrivastava, Vivek Singh, Raghunandan Prasad

Department of Nuclear Medicine, SGPGIMS, Lucknow, Uttar Pradesh, India.

Aim: The aim of this study was to find the occupational exposure of radiation to the health care workers in the Eye, Collar, Wholebody and Hand Extremities during DSA procedure in Radiology. This includes Doctors and Nurses for Wholebody dose. Materials and Methods: The study was conducted at SGPGIMS, Lucknow, in DSA Radiology. This study was done to check the occupational radiation exposure to the worker while performing the DSA procedures in DSA machine. The radiation exposure during DSA procedure is measured by the use of TLD's for Eye, Collar, Chest and Hand Extremities in a form of locket. The researcher identified that the procedures were done under three separate Units namely Gastrology, Neurology, and Vascular. TLD's for Collar, Chest, Eye & Hand Extremities separately available. Nurses a separate Chest TLD was used. Total data collected for Doctors and assisting Nurses were 583 from three different Units of Gastrology, Neurology, and Vascular. Results: The Radiation exposure to the Eye, Wholebody, Collar and Exterimities for the Hand was 0.79 mSv/hr, 0.01 mSv/hr, 0.17 mSv/hr and 1.92 mSv/hr respectively to the Doctors. Conclusion: The measured effective dose per hour for diagnostic DSA radiology was found to be the Equivalent dose limit for the Eye is 0.79 mSv/hr, for Collar is 0.17 mSv/hr, the Effective dose for Wholebody is 0.01 mSv/hr and the Equivalent dose limit for Exterimities is 1.92 mSv/hr. With respect to the study findings, the dose received in mSv/hr by the doctors was calculated to mSv/yr according to ICRP specified working hours limits (Equivalent Eye dose and Effective Wholebody dose was 0.01 mSv/hr and for Exterimties Equivalent dose was 0.25 mSv/hr) for a year. In this study it is estimated 205 mSv/yr for Equivalent Eye dose, 2.6 mSv/yr for Effective Wholebody dose and 499 mSv/yr for Equivalent Exterimities dose. The most concerning adverse effect of radiation exposure to workers was to the Eye (205 mSv/yr) and this exposure is most likely to affect the DSA radiologist because its exceeding ICRP dose limit of 20 mSv/yr, the physicians received higher dose to their Eye during DSA procedure which was 10.25 times more than the normal recommendation. The radiation dose to the Collar, Wholebody & Extremities received by the workers for three different units were well below the recommeded dose limit.


   PP5: Radioactive waste management: An issue in nuclear medicine facility Top


Pankaj Tandon, S. C. Kheruka

Atomic Energy Regulatory Board, Mumbai, Maharashtra, India.

“There are few things certain in life – one is death, second is change and the other is waste.” Radioactive materials have been found to be very effective when used in a variety of medical applications for diagnostic, therapeutic and research purposes. In nuclear medicine, there are various short-lived unsealed radionuclides used for diagnostic and therapeutic purposes. The radiopharmaceutical for patient administration may be made either by labeling the ready to use kits with the readily available radionuclide or to an eluate obtained from the parent radionuclide i.e. from generator. As a consequence of handling these radio-pharmaceuticals, a wide range of radioactive waste is likely to be produced. The waste generated includes contaminated materials and syringes, unused radio-pharmaceuticals in the vial, used radionuclide generator, as well as sealed sources used for calibration purposes. Thus, the radioactive waste generated may be categorized either of solid, liquid and gaseous form. As per the regulatory requirement, the waste generated needs to be managed in a safe manner to ensure protection of human health and the environment from the undue effects of ionizing radiation now and in the future without imposing undue burden on future generations. Objective of this article is to establish the methodology, which shall be fulfilled for the safe management of solid, liquid and gaseous radioactive waste from generation through safe disposal. It has always been a topic of discussion in the nuclear medicine facility that what is the suitable method for disposal of the radioactive waste generated. Mostly, the matter of concern is the waste generated due to the used column generator and the sealed sources used for calibration of PET scanners. As per the international instrument, code of conduct of the safety and security of radioactive sources, the imported disused sources should be repatriated to the country of origin but many times this repatriation is a challenge due to various reasons. Radioactive waste is managed in a manner that ensures compliance with the fundamental principles of radiation protection and environmental safety. Monitoring and surveillance programme prepared by the facility helps to ensure radiation protection of the occupational workers, public and the environment. It is the responsibility of the facility that emergency preparedness plan needs to be put in place for minimizing the radiological and environmental impact. The basic principle that needs to be followed during the radioactive waste management is that it should be managed within the dose constraints and other safety requirements prescribed by the regulatory body. Effective management of radioactive wastes involves segregation, characterization, handling, treatment, conditioning and monitoring prior to final storage/disposal.


   PP6: Regulatory requirements and radiation safety aspects for Yttrium-90 based radioembolization during treatment of hepatocellular carcinoma Top


K. Jolly Joseph, Pankaj Tandon

Atomic Energy Regulatory Board, Mumbai, Maharashtra, India.

Aim: Radioembolization is a procedure in which embolization and radiation therapy is combined to treat hepatocellular carcinoma or hepatic metastases from colorectal cancer. In this procedure tiny glass or resin beads (microspheres) filled with the radioactive yttrium (Y-90) is placed inside the blood vessels that feed a tumor in the liver and thereby blocking the supply of blood to the cancer cells and delivers a high dose of radiation to the tumor. In this paper, regulatory requirements and radiation safety aspects are deliberated for a facility which intends to carryout Y-90 based radioembolization. Regulatory Requirements: A facility which intends to carry out Y-90 based radioembolization should have nuclear medicine (NM) and the cathlab facility Licensed by the regulatory body. Also, in the cathlab facility one room should be allocated for the storage and handling of the Y-90 radionuclide. The cathlab also required to have qualified radiation safety professional such as interventional radiologist, radiographer etc., as stipulated in the relevant safety code of AERB. Furthermore, the procedure should be carried out under the guidance of approved Radiological Safety Officer (RSO) of nuclear medicine and cathlab facility. Suitable dose calibrator and survey meter with valid calibration should be available with the facility. Also, the radiation workers associated should be provided with personnel monitoring TLD badges. When the radionuclide is transported in-house from the NM facility to Cathlab or vice versa, stipulated regulatory requirements should be followed. Radiation Safety Aspects: NM and cathlab facility should follow practices of time, distance, and shielding during the handling of radionuclide. All the required safety procedures should be adhered during administration of the radionuclide. Suitable safety accessories (lead apron, thyroid shield, leaded eyewear etc) and appropriate radiation shields such as acrylic should be used during the procedure. RSO should ensure that no pregnant staff is available in the cathlab during the procedure. Post procedure, radiation survey of all the staffs involved should be conducted to identify any possible radioactive contamination. Radioactive waste generated should be managed as per the stipulated regulatory requirements. Post-treatment surgical procedures should be done in consultation with the RSO of the facility. In case of patient death, procedures laid down by the regulatory body should be followed.


   PP7: Archival in nuclear medicine Top


A. M. Samuel

Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.

As nuclear medicine ages in India, information and data will slowly be lost as the old generation dies out and the new generation replaces them. The gradual fading of memories and the loss of precious knowledge can never be garnered and replaced. Hence it is of utmost importance to use this opportunity while some of the older generation can still be availed of, to contribute to the purpose of the archives and add vignettes from their personal experiences and knowledge. Objectives: Preserve and record the progress of nuclear medicine in India. Save records of historical development and events in nuclear medicine. Segregate data in static and active aspects constant evaluation and entry of different development contributions and aspects of nuclear medicine a. Clinical--- Therapy and diagnostics, Teaching files b. Instruments c. Radiochemistry d. Education e. Rules and regulations f. Spread of centers in the country g. Intra and inter-country projects h. Achievements of Individuals and societies. i. Data bases for comparison and use in Nuclear medicine departments in the country. Responsibilities: A core committee of active and retired members (latter have time to spare) should shoulder the responsibility. They can be selected from: A College of Nuclear medicine B. Society of Nuclear medicine. Funds: A special corpus should be assigned for the purpose of the archives. 1 Contributions should be made from excess funds of conferences 2 Members may be requested to volunteer contributions as per their capacity. 3 If members wish to start orations they may be persuaded to instead contribute to the archives and their names can be appended to indicate their monetary efforts towards nuclear medicine.Availability of Archives: Archives should be available with college of Nuclear Medicine Society of Nuclear Medicine. Accessibility of Archives: Clinical and non clinical nuclear medicine specialists Trainees in nuclear medicine. Conclusion: Archival of data in Nuclear medicine in India needs to be initiated and maintained. An important activity in any walk of life.


   Oral Presentation: Radiopharmacy and Preclinical Top



   OP1: Tc-99m tamoxifen: A diagnostic tool for estrogen receptor expressing breast cancers Top


Anupriya Chhabra, Jaya Shukla, Rajender Kumar, Rakhee Vatsa, Amanjit Bal1, Gurpreet Singh2, Bhagwant Rai Mittal

Departments of Nuclear Medicine, 1Histopathology and 2General Surgery, PGIMER, Chandigarh, India.

Aim: Tamoxifen is an FDA approved drug for estrogen receptor (ER) expressing breast cancers. Radiolabeling of tamoxifen with Tc-99m will lead to the development of diagnostic radiopharmaceutical for ER expressing breast cancer patients. Materials and Methods: Tamoxifen was radiolabelled in-house via Tc-99m tricarbonyl core. In-vitro receptor binding studies were performed in ER (MCF-7) and non-ER (MDA-MB-231) expressing cell lines. Biodistribution studies were performed in female wistar albino rats. Tc-99m-tamoxifen and F-18-FDG PET/CT imaging was performed in four biopsy proven ER expressing patients. Results: Tamoxifen was radiolabeled with Tc-99m with more than 95% radiochemical purity. Tc-99m tamoxifen was found to be sterile and apyrogenic (>175 EU/ml). Radiocomplex was characterized by MALDI-TOF and 1H-NMR. Tc-99m-tamoxifen demonstrated 30% binding towards ER with MCF-7 cell line. Binding was inhibited by 72% when pretreated with 50 molar excess tamoxifen. Only 1-3% binding was observed with MDA-MB-231 cell line. Normal biodistribution of Tc-99m-tamoxifen was seen in breast, heart, liver, lungs and spleen. Tc-99m-tamoxifen SPECT/CT image of the three patients showed uptake in breast and other lesions. The images were in concordance with F-18-FDG PET/CT findings. Uptake of Tc-99m-tamoxifen was not observed in fourth patient as she was already taking tamoxifen (20 mg/day) from last six months. However, breast and other metastatic lesions were visualized on 18F-FDG PET/CT scan results. Conclusion: This study suggest that Tc-99m-tamoxifen is useful for ER imaging. Also, it is very beneficial for the centres not having onsite cyclotron facility. More patient data is needed to validate the findings.


   OP2: Synthesis and imaging of F-18 prostate specific membrane antigen-1007: Institutional experience Top


Karan Singh Tanwar, Rakhee Vatsa, Jaya Shukla, B. R. Mittal

Department of Nuclear Medicine, PGIMER, Chandigarh, India.

Aim: Ga-68 PSMA is a widely used tracer for imaging disseminated prostate cancer patients. Ga-68 being a generator produced radionuclide has limitation of number of elutions per day. Rise in number of prostate cancer patients worldwide lead to development of F-18 PSMA for imaging prostate cancer in centres where number of patients are more. The present study aims to share the preliminary experience of F-18 PSMA-1007 synthesis and imaging in prostate cancer patients. Materials and Methods: F-18 was produced using O-18 as target material by p,n reaction in medical cyclotron. Radiosynthesis was done in cassette based automated module (ORA Neptis) using commercially available kit. After performing all the initial checks cassette was placed in the module. After passing the quality control tests of the cassette, reagents vial and precursor were placed at appropriate positions. C18ec and PS-H+ cartridges were used for purification. TBA was used as eluent. ITLC was performed on silica strip using 60% ACN as mobile phase. Apyrogenecity was tested using PTS system and sterility were tested by incubating the samples in fluid thioglycollate and soybeancasein medium at 370C for upto 7 days. Wholebody PET/CT imaging was performed in total 15 patients at 45-60 min post IV injection of 7-8mCi of F-18 PSMA-1007. Results: The total synthesis time was 40 min post F-18 delivery in module. Radiolabelling yield of 30-40% was achieved. Formulation was found to be sterile and endotoxin content was ranging from 1.98-2.75 EU/ml which is well below permissible limit (175 EU). Biodistribution of F-18 PSMA-1007 was found to be almost similar to Ga-68 PSMA. F-18 PSMA-1007 has reduced urinary clearance enabling assessment of the prostate. High target to background ratio was observed in both primary and metastatic lesions. Conclusion: 18F-PSMA-1007 performs at least comparably to Ga-68 PSMA, it also overcomes some practical limitations of Ga-68 labelled PSMA targeted tracers because of longer half-life combined with its superior energy characteristics and low urinary excretion. Due to high radiolabelling yield of 18F-PSMA-1007, multiple tracer syntheses per day is not required as it is needed in Ga-68 PSMA. 18F-PSMA-1007 can also be transferred to satellite centers.


   OP3: Preliminary experience of 68Ga-BPAMD for imaging distant bone metastases in cancer patients Top


Damanpreet Kaur, Jaya Shukla, Rakhee Vatsa, Bhagwant Rai Mittal

Department of Nuclear Medicine, PGIMER, Chandigarh, India.

Aim: Bone is known to be the third most common site of metastases, besides lung and liver. A non-invasive early diagnosis of bone metastases helps in deciding subsequent therapy for the patient. The present study aims to evaluate the potential of 68Ga labeled BPAMD as a diagnostic agent for detection of distant bone metastasis. Materials and Methods: BPAMD kits available from BRIT were used for radiolabeling with 68Ga in semi-automated fluidic module. 68Ga was eluted in the form of 68GaCl3 using 0.05 M HCl from commercially available silica based 68Ge/68Ga generator. The contents of the kit were dissolved in 400 μL of HPLC grade water. The solution was transferred to the reactor vessel of fluidic module and incubated with 68GaCl3 at 95°C for 20 minutes. Radiolabeling yield and radiochemical purity were calculated via paper chromatography using 0.5 M Na-citrate buffer as mobile phase. A total of 7 patients have undergone whole-body PET/CT scan from base of skull to mid-thigh 45 min post intravenous administration of 4-5 mCi of 68Ga-BPAMD. Result: Radiolabeling yield of >99% was achieved by incubating the reaction mixture in 2 ml at 95 °C. Uptake of 68Ga-BPAMD was similar to 99mTc-MDP. Abnormal intense and focal uptake of 68Ga-BPAMD was observed in skeletal lesions. Good target to background ratio was observed at 45 min. Conclusion: 68Ga-BPAMD was prepared with good radiolabeling yield and radiochemical purity. Better image quality was additional benefit due to PET imaging. BPAMD can further be explored for radiolabeling with 177Lu for bone pain palliation.


   OP4: Formation and evaluation of doxorubicin containing silk fibroin nanoparticles and its direct labeling with 99mTc Top


Vikas Pandey, Ashok R. Chandak, Avik Chakraborty, Sharmila Banerjee, Vandana Soni

Dr. Hari Singh Gour University, Sagar, Madhya Pradesh, India.

Aim: Doxorubicin (DOX) is a most potent and anthracycline anticancerous drug which is widely used in clinical oncology for the treatment of various cancers. Silk fibroin (SF), a protein-based natural biomaterial, has emerged as a biocompatible biomaterial for drug delivery systems. Coating of SF nanoparticles with Tween-80 enhances the transportation of drug across the BBB. Technetium-99m (99mTc) has been widely used for labeling radiopharmaceuticals, due to certain advantages like chemical and physical characteristics, large and easy availability, and low isotope cost. In this study, we describe the direct labeling of drug DOX, SF nanoparticles and Tween-80 coated SF nanoparticles with 99mTc. Further, the quality and cell uptake have been evaluated for labeled products. Materials and Methods: The SF nanoparticles were prepared by nanoprecipitation method and characterized for different parameters, like surface morphology and vesicle shape, size, entrapment efficiency, and in vitro release pattern. The labeling of 99mTc with DOX, SF nanoparticles, and Tween-80 coated SF nanoparticles were done by using a different concentration of reducing agent. Paper chromatography was used for performing the radiochemical purity of the product in acetone and saline. In-vitro stability of the 99mTc labeled products in saline and fresh human serum was performed along with the transchelation with DTPA. The in-vitro cell uptake studies were performed on the C6 glioma and LN-229 cancer cell lines. Results: The 99mTc labeling efficiency with DOX and SF nanoparticles was found to be more than 90%. The maximum labeling efficiency was found to be at 20 μg stannous chloride, pH 5-6, and 200 μg of DOX at room temperature. The product found to be stable in serum and tranchelation study. Cellular uptake was higher in Tween-80 coated SF nanoparticles as compared to plain SF nanoparticles and free drug. Conclusion: DOX and nanoparticles were successfully labeled with 99mTc and optimized for the different parameters showing high in-vitro stability in saline and fresh human serum. These SF nanoparticles could serve as a vector for the delivery of the drug to brain.


   OP5: Preparation and preliminary biological evaluation of 177Lu-DOTA-exendin-4 for radiotherapy of insulinomas Top


Mohini Guleria, Tapas Das, Jeyachitra Amirdhanayagam, Haladhar D. Sarma, Ashutosh Dash

RMC, Mumbai, Maharashtra, India.

Aim: 177Lu-DOTA-Ahx-Lys40-Exendin-4 (177Lu-DOTA-Exendin-4) is a potential agent for radiotherapy of insulinomas owing to its specificity towards GLP-1 (Glucagon like peptide-1) receptors over-expressed on such cancers. The objective of the present work is to study and optimize the various radiochemistry parameters for the consistent formulation of the agent with high radiolabeling yield using carrier added 177LuCl3 and also to evaluate its biological behaviour in small animal model. Materials and Methods: In order to optimize the radiolabeling parameters, DOTA-Exendin-4 was radiolabeled with 177Lu, obtained from a medium flux research reactor using direct (n,γ) route, in two different buffer systems (sodium acetate and HEPES) at three different temperatures (45, 65 and 95 °C) using three different ligand to metal ratios (3:1, 4:1 and 5:1). The radiolabeled peptide was characterized by both paper chromatography and High Performance Liquid Chromatography (HPLC). The effect of addition of three different radio-protectors on complexation yield was also studied. Bio-distribution studies were carried out in normal Swiss mice to evaluate the pharmacokinetic behaviour of the radiolabeled peptide as well as to determine the in-vivo specificity of the radiotracer towards GLP-1 receptors (blocking studies). Urine and kidney lysate of the animals were analyzed at various post-administration time-points in order to determine the in-vivo stability of the radiolabeled peptide. Results: The 177Lu-DOTA-Exendin-4 complex could be prepared consistently with >95% radiolabeling yield using the optimized reaction conditions (HEPES buffer, L:M ratio = 5:1, incubation at 95 °C for 1 h). Bio-distribution studies revealed early accumulation of 177Lu-DOTA-Exendin-4 in pancreas along with fast clearance via renal pathway. Significantly high accumulation of the radiotracer was observed in the kidneys. Analyses of urine and kidney lysate of the animals revealed in-vivo stability of 177Lu-DOTA-Exendin-4. Blocking studies showed displacement of significant amount of radiotracer from GLP-1 receptor-positive organs such as, pancreas and lungs (p<0.05) in presence of unlabeled peptide, indicating the specificity of the radiolabeled preparation towards GLP-1 receptors. Conclusion: Present study shows that 177Lu-DOTA-Exendin-4 could be formulated for radiotherapeutic application of insulinoma with high radiochemical purity and adequate in-vivo stability using carrier added 177Lu produced via direct neutron irradiation without the requirement of any post-labeling purification.


   OP6: Synthesis and comparative evaluation of 68Ga-labeled DOTAGA, NODAGA and HBED-CC conjugated iRGD peptide analogues as tumor targeting agents Top


Drishty Satpati, Kusum Vats, Haladhar Dev Sarma, Ashutosh Dash

BARC, Mumbai, Maharashtra, India.

Aim: Internalizing RGD (iRGD) motif with sequence c(CRGDKGPDC) belongs to the class of integrin targeting peptides and is conferred with additional characteristic of tissue penetration. The iRGD peptide on binding to cell surface integrins gets proteolytically cleaved to the fragment CRGDK thereby achieving affinity towards neuropilin-1 receptors (NRP-1). In this study iRGD peptide has been conjugated with three different chelators for 68Ga-labeing and their comparative evaluation has been performed. Materials and Methods: The peptide CRGDKGPDC was assembled on solid phase resin using standard Fmoc synthetic strategy. The N-terminus of the peptide was then conjugated with chelators DOTAGA(tBu)4 /NODAGA(tBu)3 /HBED-CC-tris(t-Bu)ester followed by on-resin cyclization and cleavage. The peptide conjugates were purified using semi-preparative HPLC and radiolabled with 68GaCl3 (185 MBq) eluted from 68Ge/68Ga generator (ITG, Germany). In vivo evaluation of three radiotracers, 68Ga-DOTAGA-iRGD, 68Ga-NODAGA-iRGD and 68Ga-HBED-CC-iRGD were carried out in C57BL/6 mice bearing melanoma tumor. Results: The three radiotracers 68Ga-DOTAGA-iRGD, 68Ga-NODAGA-iRGD and 68Ga-HBED-CC-iRGD were prepared with >98% radiochemical purity as determined by RP-HPLC and were observed to be stable in-vitro till 3 h post preparation. The uptake of 68Ga-DOTAGA-iRGD, 68Ga-NODAGA-iRGD and 68Ga-HBED-CC-iRGD in murine melanoma tumor were 1.2±0.2% ID/g, 2.1±0.2% ID/g and 2.4±0.6% ID/g respectively at 1 h p.i. 68Ga-HBED-CC-iRGD and 68Ga-NODAGA-iRGD exhibited higher uptake in non-target tissues in comparison to 68Ga-DOTAGA-iRGD. The predominant route of excretion was through renal pathway for all the three radiotracers. Conclusion: In the present report influence of three different chelators, DOTAGA, NODAGA and HBED-CC on the biodistribution pattern of 68Ga-labeled iRGD peptides was studied. 68Ga-HBED-CC-iRGD and 68Ga-NODAGA-iRGD exhibited similar biodistribution pattern however 68Ga-DOTAGA-iRGD displayed higher target-to-non-target ratio.


   OP7: A feasibility study to explore the possibility to perform Lu-177 based therapy in a daycare unit: Interim report Top


Ashish Kumar Jha, Sneha Mithun, Uddeshya Narayan Jha, Ravi Kumar Chauhan, Subrat Pathak, Shimja Bhanu, Manisha Inamdar, Pankaj Tandon, Venkatesh Rangarajan

TMH, Mumbai, Maharashtra, India.

Introduction: Radionuclide therapy is several decade old and tested modality to treat cancer patients with radionuclide. A variety of radionuclides were tested and used to perform these therapies. Till few year back majority of therapies performed in Nuclear Medicine were I-131 based radionuclide therapies. But in last few year several isotopes and radiopharmaceuticals are being used, among all Lu-177-DOTATOC and Lu-177 PSMA therapies are the two very important therapies being performed routinely. As per the current regulations in our country, all the radionuclide therapy should be performed in high dose therapy ward with delay tank facility. Since, Lu-177 is non-volatile and also it has very low gamma constant in comparison with I-131, Lu-177 based radionuclide therapy may be considered as outpatient therapy. A study performed by Phillipe J. Calais and J. Harvey Turner in Australia, found Lu-177 based therapy to be suitable for outpatient treatment if all the radiation safety precautions has been taken. Current IAEA guidelines do not mandate the requirement of delay tank for radionuclide therapy.Tata Memorial Hospital along with Atomic Energy Regulatory Board (AERB) has proposed a study to find out the possibility to perform Lu-177 based therapy on OPD basis. Materials and Methods: An existing decommissioned brachytherapy ward at TMH has been modified as per AERB recommendations to perform this study. Study had been designed to perform Lu-177 based therapies in this HDT ward. Following parameters were evaluated: 1) Surface and 1 meter dose rate from the patient at 0 hr, 1 hr, 2 hr, 3 hr, 4 hr, 8 hr, and 24 hr., 2) Activity concentration of discharged affluent at 2 hr, 4 hr, 8 hr, 24 hr from the pit inside the Tata Memorial Hospital., 3) Radiation exposure received by Nuclear Medicine Physician, Nurses and Technologists during the procedure., 4) Radiation dose received by the comforters post administration during the stay of patient in the therapy ward, 5) Activity discharged through urine in 4 to 5 hrs after administration of therapeutic dose was measured, 6) Radiation dose the the eye to the person administering the dose was also calculated. Radiation survey and patient monitoring were performed using RemGene survey meter and radiation counting was performed using Pla Electro Spectrometer. Results: Total 64 patients treated with Lu-177 DOTATOC/Lu-177 PSMA, were included in this study. The average surface and 1 meter dose rate from the patients are given in [Table 1]. The average thigh surface dose rate at 24 hrs was 8.12 μSv/h. The average radiation exposures to the nuclear medicine physicians, nurses and technologists working in HDT ward were 9.7 μSv, 6.1 μSv, 2.6 μSv per procedure respectively. The average activity concentration of discharged affluent in the pit at 2 hr, 4 hr, 8 hr, 24 hr were 3.82 Bq/cc, 11.55 Bq/cc, 10.35 Bq/cc, 2.25 Bq/cc respectively. The average radiation dose received by eye of the professionals during the injection of radiopharmaceutical was found to be 0.13 μSv/procedure. The percentage radioactivity execrated in urine in first 5 hours after administration in Lu-177 DOTATOC therapy was 36%. The average radiation exposure to the comforter during the patient stay in the ward was 59.5 μSv per procedure. Conclusion: Initial report of our study suggests that, the external radiation exposure to the professionals, relative and general public can be maintained well within the permissible level even the Lu-177 based therapy is performed on daycare basis.
Table 1: Average dose rates at different time intervals

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   OP8: Comparative study of Lu-177-trastuzumab dosimetry performed by manual method using multiple planar whole body images and GE dosimetry toolkit method using multiple single-photon emission computed tomography/computed tomography images Top


Amit Nautiyal, Viraj Sawant, Ashish K. Jha, Sneha Mithun, Jay Prakash, Beena Shetye, Sneha Shah, Venkatesh Rangarajan

TMH, Mumbai, Maharashtra, India.

Aim: The use of Lu177 trastuzumab monoclonal antibody as radioimuunotherapy agent is increasing widely in metastatic breast cancer. Like other antibody, Lu177 trastuzumab clearance from body is very slow and it has also been shown in several biodistribution studies. Due to slow clearance of Lu177 trastuzumab from body, several vital organs receive significant radiation dose. Hence, pre therapeutic dosimetry of Lu177 trastuzumab is utmost important to achieve the desired benefit of the treatment. Internal radiation dosimetry is a tedious and time consuming process. There several softwares are available to perform internal dosimetry based on planar as well as SPECT images. We have purchased Dosimetry Toolkit, GE Medical system and Olinda software to perform the same. Aim of our study was to compare Lu-177-trastuzumab dosimetry performed by manual method based on multiple planar studies with that dosimetry Tool Kit method based on multiple SPECT/CT studies. Methods: Total 5 female patients (age: 43.8 ±7.0 yrs, weight: 53.2 ±8.10 kg) who underwent Lu-177-trastuzumab dosimetry study in our department were included in this study. After administration of 6-7 mCi Lu177 trastuzumab, multiple SPECT/CT and planar whole body images were acquired at five imaging time points up to 7 days using discovery NM/CT 670 pro, GE medical systems. Planar images were used to estimate the organ activity and residence time for each organ manually, using conjugate view method, trapezoidal rule and direct exponential. Dosimetry toolkit software was used to estimate the residence time in organs directly from the multiple SPECT/CT images. In manual method, attenuation correction of planar image was performed using Chang method and CT based attenuation correction was performed in toolkit method. Dual energy window method was used to perform scatter correction in both the methods. Organ volume was measured using Q. Matrix software. Radiation dose for heart, liver, spleen, kidneys, urinary bladder and remaining body were calculated using OLINDA/EXM 2.0. Results: The mean administered activity of Lu177 trastuzumab was 6.9 (±0.69) mCi. The mean cumulative activity (uCi-hr) estimated by manual method for heart, liver, spleen, kidneys, urinary bladder and remainder body were 109063 ±27863, 247839 ±79846, 35505 ±21613, 39339 ±16711, 12596 ±8597, 96299 ±43854 respectively. The details of residence time and radiation dose calculated for various organs using manual as well as toolkit method are mentioned in [Table 1]. Conclusion: Manual method estimates significantly higher residence time and radiation dose to the organs in comparison of dosimetry tool kit method.
Table 1: Radiation dose to different organs

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   OP9: Simple and convenient strategy to transform the waste 68Ga-prostate specific membrane antigen into injectable product Top


Mehjabeen, M. Priya

TMH, Mumbai, Maharashtra, India.

Objective: The aim of this work is to transform the waste Ga-68 PSMA into a useable, injectable product having RCP & pH comparable to that of a successful production using only new Sep pak c18 cartridge. In this way, labelling is possible saving the complete production process with good radiochemical yields and purity while maintaining the high quality of the final product. Methods: The semi automated process starts with a vacuum-assisted ITG fluidics system where 68 GaCl3 is eluted with 4 mL of a 0.05 M HCl solution from the Ge-Ga generator and sent to the reaction vessel. PSMA-11 labeling employs a solution of 5 μg peptide in 1 mL 0.25 M acetate buffer which is then heated at 95°C for 5 min. After the reaction labelled Ga-68 PSMA is loaded onto a Sep-pak® Light C18 cartridge and washed with 5 mL of saline. The unlabelled substances get transferred to the waste vial. 68Ga-PSMA-11 is then eluted with 1 mL of Ethanol followed by 5 mL of saline and collected through a 0.22 μM Millex®-GV filter into a sterile product vial. In case of a larger amount of activity in the waste, the waste contents were made to undergo the same procedure again, simply by using a newly conditioned Sep pak c18 cartridge. Observation: Although the normal method is very much reliable but sometimes on some occasion we have found that during the process of loading labelled product onto the cartridge, Ga-68 labeled PSMA is not present in product vial and it gets eluted in waste vial. Our observation perceived that it could be probably due to a faulty cartridge. Hence we used the eluent from the waste vial and filtered it again through pre conditioned Sep-pak® Light C18 cartridge. Results: The process took another 5 mins to reproduce injectable 68Ga-PSMA-11 with high radiochemical purity TLC > 98.5 % & .pH 5-5.5. Conclusions: Solution obtained in the waste of a 68Ga-PSMA-11 labelling was converted to injectable product using an ITG fluidics system without adding new peptide. We used only a new pre conditioned Sep-pak® Light C18 cartridge for labeling without compromising the radiochemical yields and the quality of final product. Thus this method can salvage the whole process and obviates the waste of peptide and can be employed to support the economy of the department.


   OP10: A generic ready-to-use 177Lu-prostate specific membrane antigen-617 formulation for prostate cancer therapy Top


Navin Sakhare, Ajish Kumar1, P. C. Vrinda, Anupam Mathur, N. C. Joseph, Bikash Tiwari, Sana Sayyad, S. Ravi, K. Barkha, Chanda Arjun, V. Rangarajan2

Radiopharmaceuticals Program, Board of Radiation and Isotope Technology, Navi Mumbai, 1Bio-Organic Division, Bhabha Atomic Research Centre, 2Tata Memorial Hospital, Mumbai, Maharashtra, India.

Aim: 177Lu-PSMA-617 is now a proven therapeutic radiopharmaceutical for the treatment of metastatic castration-resistant prostate cancer (mCRPC). The raw material PSMA-617 peptide used for its production is currently imported by hospitals at exorbitant cost and labeled with 177Lu to yield the final radiopharmaceutical. Recently PSMA-617 raw material has been indigenously synthesized by BARC and a suitable cost-effective radioactive formulation has been developed for patient end use. Materials and Methods: PSMA-617 was synthesized on peptide synthesizer following conventional Fmoc-solid phase peptide synthesis. The peptide produced was conjugated with DOTA chelator and purified by semi-preparative HPLC. The peptide DOTA conjugate was characterized by NMR, HRMS and HPLC. The identity was further established on comparison with commercial PSMA-617 material. The peptide was then radiolabeled with 177Lu to yield the desired radiopharmaceutical. Briefly, 177Lu-PSMA-617 is synthesized by reaction of 177Lu (Sp. act. >15 Ci/mg; 200 mCi) with PSMA-617 peptide (2.0-2.5 equivalents) in sodium acetate buffer (0.1 M). This is then diluted with sodium acetate (0.1 M, pH 4) buffer containing 2% sodium ascorbate and sterilized by membrane filtration and dispensed as single patient dose (200 mCi). Clinical evaluation in diseased cancer patients have been conducted at TMH, Mumbai to evaluate the therapeutic effectiveness of the product. Results: A peptide/metal ratio of 2.0-2.5 is essential for obtaining complexation yields >95%. The labeled formulations with radioactive concentrations < 20 mCi/mL and containing 2% w/v sodium ascorbate in 0.1 M sodium acetate buffer is observed to be safe for human use up to 5 d (RCP > 98%) when stored at -20°C. Clinical trials conducted with >15 batches in diseased prostate cancer patients exhibited distribution at the tumor and its metastatic site and desired therapeutic effect achieved. Conclusion: Therapeutic doses of clinical grade ready-to-use 177Lu-PSMA-617 for prostate cancer therapy is now approved by Radiopharmaceuticals committee and is launched by BRIT as a regular product.


   OP11: 68Ga-labeled peptide probe for targeting human epidermal growth factor receptor 2 receptor expression in breast cancers Top


Amit Kumar Sharma, Kusum Vats, Tapas Das, Drishty Satpati, Ashutosh Dash

Bhabha Atomic Research Center, Mumbai, Maharashtra, India.

Aim: Human epidermal growth factor receptor-2 (HER2) is a crucial biomarker for breast cancer and associated with poor prognosis. HER2-targeted molecular probes therefore have significant implications in imaging and therapy of breast cancers. Radiolabeled antibodies (trastuzumab, pertuzumab) have been developed for targeting HER2 receptor expression in breast cancers, but long blood circulation time limits their effectiveness. Here we have attempted to develop a 68Ga-labeled peptide probe as a HER2 targeting tracer. Materials and Methods: The peptide, DOTA-PEG4-Gln-Asp-Val-Asn-Thr-Ala-Val-Ala-Trp (DOTA-PEG-A9) was synthesized using standard protocols of Fmoc solid phase peptide chemistry and purified using semi-preparative HPLC. 68Ga-labeling of DOTA-PEG-A9 was carried out by addition of 68GaCl3 (185 MBq) eluted from 68Ge/68Ga generator (ITG, Germany) to the peptide (50 μg) dissolved in sodium acetate buffer (100 μL, 1.5 M, pH 4) followed by incubation (80°C, 10 min). Radiolabeling yield and stability of 68Ga-DOTA-PEG-A9 was determined by RP-HPLC. Results: DOTA-PEG-A9 could be synthesized in >99% purity. Radiolabeling yield of 68Ga-DOTA-PEG-A9 was >98% as determined by RP-HPLC. The radiotracer was observed to be hydrophilic (log P = -3.290.1). Stability studies were carried out after 2 h of preparation of radiotracer and no change in retention time or radio-chromatogram pattern indicated stability of 68Ga-DOTA-PEG4-A9. Conclusion: Peptide-based HER2 targeting molecular probe, 68Ga-DOTA-PEG-A9 has been synthesized in high yields and exhibited adequate in vitro stability. In vitro and in vivo evaluation studies for confirming its receptor specificity are in progress.


   Poster Presentation: Radiopharmacy and Preclinical Top



   PP1: Synthesis and preliminary studies of estradiol conjugated nanoparticles for cancer targeted theranostics Top


Garima Mann, M. Thirumal, Ankur Kaul, A. K. Mishra, Anupama Datta

INMAS, Delhi, India.

Aim: ER+ breast cancer is the most frequently occurring type of malignant breast tumor occurring in 2 out of 3 cases. The recommended mode of therapy is based on hormone receptors. Targeting estrogen receptors thus prove to be an accurate and effective target for both diagnostic and therapeutic purposes. Mesoporous silica nanoparticles have been extensively utilised for targeted drug delivery owing to their ability to deliver large loads of cargo. The drugs are encapsulated in the pores while the surface can be modified to make the nanoparticles target specific and increase their retention time in the bloodstream. The work being presented here focusses on developing theranostic nanoparticles with ER+ breast cancer as the target. The pores were utilized for drug encapsulation while the surface was dually functionalised to make the nanoparticles target specific as well as attach a SPECT imaging probe for imaging purposes. Materials and Methods: The nanoparticles were synthesised by a modified Stober process. The estrogen target was attached by a facile and clean green synthesis “click” chemistry. The surface was further modified to attach DTPA chelator and finally, MSNs were loaded with the drug. Morphology and surface functionalisation was characterised using SEM and IR analysis. The size was calculated using the DLS instrument. Results: Dual functionalised spherical Mesoporous Silica Nanoparticles were successfully synthesised and characterised using IR and TGA analysis. The DLS data confirmed the nm size range of functionalised mesoporous silica nanoparticles. SEM and TEM analysis confirmed the morphology and size. Conclusion: Surface grafted MSNs are efficient diagnostic as well as therapeutic tools where the drug is encapsulated in the pores and active targeting and diagnostic ligand are present on the surface. Radiolabelling studies with 99mTc are underway. Further in vitro and in vivo studies will be carried out to establish the efficacy of these nanoparticles for targeting ER+ breast cancer.


   PP2: Synthesis of generator based 68Ga-labeled prostate specific membrane antigen 11 by a new reliable and fast method Top


Rajeev Kumar, Nishikant A. Damle, Madhavi Tripathi, C. S. Bal

AIIMS, New Delhi, India.

Aim: To share our experience regarding the synthesis and quality control of generator based 68Ga- labeled PSMA 11 by a new efficient most reliable and fast method. Materials and Methods: The 68Ge/68Ga generator was eluted by 0.05 N Hcl in to reaction vessels. The volume of Hcl was 4 ml. The reaction vial contained gallium precursor PSMA11 dissolved in buffer at pH of 4.5. In old method, the reaction vessel was heated for 95 degree for 7 to 12 minutes. Once heating was completed it was cooled and diluted by adding metal free water. But in new method there is no need of heating. Now the product was transferred in to the t-C-18 cartridge for purification. From this cartridge product was transferred in to product vial with the help of a solution containing mixture of Ethanol and metal free water (60:40 ratio). Product was passed through 0.22 μm filter. This product is diluted by adding 10 ml normal saline. All the synthesis steps were carried out in a manual module. The total synthesis time was 12 minutes. Quality control test (Clarity, pH, Radiochemical purity) was performed. Stability was checked by running chromatograms immediately after the preparation and later at 1, 2, 3 and 4 hours. Results: The yield of 68Ga-PSMA 11 was approximately 90%. 68Ga-PSMA11 was prepared with very high chemical purity (>99 %). The product is carrier free (without 68Ge). The labeled cPSMA11 was clear with pH range 5.5-6.0 The product was stabile up to four hours at room temperature. There was no significant free 68Ga.The product was stabile up to four hours. Conclusion: We synthesized generator based PET radiotracer 68Ga-PSMA11 with high radiochemical purity and good stability. Generator based PET radiotracer 68Ga-compound can be synthesized with high radiochemical purity with good stability by a new efficient most reliable and fast method.


   PP3: Synthesis, radiolabelling and molecular docking studies of 18F labelled coumarin-triazole hybrids as galectin-1 targeting positron emission tomography diagnostic agents Top


N. Sridhar Goud, Raman Joshi, Chandana, Rose Bharath Dhawan, Pardeep Kumar

NIMHANS, Bengaluru, Karnataka, India.

Background: Human Galectin-1 (Gal-1) protein is regarded as a molecular target in the treatment of cancer due to its a fundamental role in various biological events like angiogenesis, metastasis, apoptosis, and invasion. The overexpression of Gal-1 is reported in many of cancer types like the brain, breast, osteosarcoma, lung, prostate, melanoma, etc. Gal-1 is considered as a biomarker in diagnosis, prognosis and treatment condition of various cancer & neurological conditions. Hence, overexpression of Gal-1 in multiple cancer cells & importance of positron emission tomography (PET) imaging modality for diagnosis, have triggered our interest to develop novel radiotracer fluorine-18 labeled Gal-1 inhibitors as diagnostic imaging agents. Materials and Methods: A series of two novel coumarin-triazole hybrids (6a-6b) have been synthesized and radiolabelled with 18F radio isotope, using the precursor concentration- 5-6 mg, molar ratio of precursor/[K222/K2CO3]- 0.25-0.5/1, Reaction temperature- 110-120°C, Solvent- DMF, Pressure (kPa)- 0-200, Time (min)- 15 min. The hybrids and radiolabelling were confirmed by analytical techniques like 1H-NMR, 13C-NMR, TLC & HPLC studies. Molecular docking studies revealed the binding interactions with Gal-1. Results: The coumarin-triazole hybrids (6a-6b) were obtained in good yields (70-80%) using coumarin intermediates (5a-5b) with two different benzyl azides. The HPLC studies clearly showed that the target hybrids (6a-6b) conjugated with 18F radio isotope and the radiolabelling output is nearly >30%. The radiochemical purity of synthesized compounds was achieved >90%. The molecular docking studies clearly indicate that the coumarin-triazole hybrids (6a-6b) making strong electronic interactions with carbohydrate binding site of Gal-1, supported our study that these novel molecules selectively targeting Gal-1 protein. Conclusion: Our studies demonstrate the 18F labeled coumarin-triazole hybrids as Galectin-1 mediated PET diagnostic agents.


   PP4: Synthesis and evaluation of picolinic acid based bifunctional chelating agent for application in molecular imaging Top


Garima Mann, Shivani, Nikhil Kumar, Sunil Pal, A. K. Mishra, Anupama Datta

INMAS, Delhi, India.

Aim: The existing bifunctional acyclic chelators are based on DOTA and DTPA derivatives. However, elevated chelation temperature or low in vivo stability limits the use of these chelators in diagnostic imaging. In this direction, a new family of chelators based on picolinic acid 'pa' family are being explored which exhibit mild labelling conditions and stable complexation with radiometals. The focus of this study was on the development of the “pa” scaffold chelate, 6,60-(2-aminoethylazanediyl) bis (methylene) dipicolinic acid, H2pentapa-en-NH2 which will be further utilized for metal complexation and targeted imaging. Materials and Methods: The chelator contains two pyridine moieties derivatized with carboxylate groups. For the synthesis of the chelator, pyridine-2,6-dicarbonyl chloride was used as a precursor and conjugated to the amine group of ethylene diamine, providing the basic skeleton of the chelate. Finally, in the last step, deprotection in 2 M NaOH gave H2pentapa-en-NH2. The developed agent was complexed with 99mTc in high radiochemical purity and yield after optimising the various parameters of radiolabeling. Further, The in vitro stability of 99mTc-pentapa-en-NH2 in PBS buffer was assessed. Results: The “pa” scaffold based chelator, H2pentapa-en-NH2 was successfully synthesized in high purity and >95% yield. The chelator was characterized using NMR and Mass spectroscopy. The radiochemical yield of H2pentapa-en-NH2 with 99mTc was found to be 97.2% by ITLCSG, and the specific activity was 135–140 MBq mmol-1. In vitro competition experiments with human serum and PBS buffer show that the 99mTc remained predominantly chelate bound with only 7% transchelated to serum proteins after 24 h. Conclusion: Picolinic acid based H2pentapa-en-NH2 chelate was synthesised using a simple and versatile synthetic approach. The developed chelate was labelled with 99mTc with a facile radiolabeling procedure for the applications in SPECT imaging. High yield of radiocomplexation and in vitro stability in PBS established enhanced biocompatibility and the suitability of chelator for complexation with other radiometals.


   PP5: Design, synthesis and bivalent approach for evaluation of prostate specific membrane antigen inhibitor 99mTc-DTPA-(Glu-urea-Lys)2 for single-photon emission computed tomography imaging of prostate cancer Top


Anju Wadhwa, Shubhra Chaturvedi, Vishakha Chaudhary, Firasat Hussain, Anil Kumar Mishra

INMAS, Delhi, India.

Introduction: Despite the emerging progress in diagnostic and therapeutic techniques, Prostate Cancer is one of leading cause of cancer related death among men in accordance to World Health Organization. The prostate specific membrane antigen is tissue specific glycoprotein and it is an important biomarker for targeting Prostate because of elevated expression in prostate cancer cells. Metallo-radiopharmaceuticals can provide superior pharmacokinetics and act as better imaging agents as compare to monoclonal antibodies and peptides due to their easy synthesis, high affinity, better tissue penetration, rapid clearance and minimal expression in other organs. A series of PET based radiotracer [18F]-fluoro dihydrotestosterone ([18F]FDHT),10-anti-1-amino-3-[18F]-fluorocyclobutyl-1-carboxylic acid (anti[18F]F-FACBC), are currently used for imaging of Prostate cancer. However due to short half life time and low urinary secretion of positron emitting radionuclide, SPECT based imaging agent are now more famous. Thus in present work, we have synthesized urea based 99mTc labeled DTPA-(Glu-urea-Lys)2 analogue for SPECT imaging of prostate cancer. The urea based inhibitors for PSMA offers advantage due to rapid clearance from other organs, leading to image with clear contrast. Materials and Methods: The synthesis involves disubstitution of glutamic acid with two moles of benzyl bromide resulting (benzyl)2 Glutamate ester. Then primary amine group of benzyl protected Glutamate ester is converted into isocyanate by treatment with thiophosgene at 0°C which is further conjugated with lysine leads to formation of urea bond. Finally Glutamate–Urea-Lysine pharmacophore is conjugated to DTPA using Et3N as base. Then resulting analogue was then radio labeled with 99mTc and the resulting complex was characterized after purification with HPLC. SPECT imaging of mice bearing PSMA tumor is underway. Results and Discussion: The DTPA-(Glu-urea-Lys)2 analogue was synthesized in more than 70% yield. The radiolabeled efficiency with 99mTc was achieved more than 90%. The in situ generation of isocyanate intermediate was confirmed by peak at 2220 cm-1 in FTIR. The purity of all analogues was confirmed by HRMS and HPLC. Future work will concentrate on SPECT imaging of PSMA tumor bearing mice. Conclusion: Compound was synthesized which demonstrate PSMA specific binding in tumor bearing mice.


   PP6: Clinical validation of [18F]-flumazenil Top


Pardeep Kumar, Raman Kumar Joshi, Vittal Korann, Sandhya Manglore, Chandana Nagaraj, Naren P. Rao

NIMHANS, Bengaluru, Karnataka, India.

Introduction: [18F]-FMZ has been used for the assessment of the gamma-aminobutyric acid (GABA) receptors using positron emission tomography (PET). We have tried various solid phase extraction (SPE) cartridges combinations and successfully established automated synthesis method for [18F]-FMZ and tested in volunteers. Aim: To develop automated labeling method for [18F-flumazenil production and its clinical validation. Methods: [18F] was produced by standard nuclear reaction using [H2O18] as a target material. The precursor nitormazenil was procured from ABX, Germany and Syncom, Netherlands. The radio-fluorination was standardized for various parameters like temperature (130-160°C), precursor concentration (3-5 mg), various combination of SPE cartridges (HLB, tC18, C18 and alumina). the crude mixture was diluted with acidic water and passed through various combinations of the SPE cartridges (HLB + tC18, HLB + C18, C18 + Alumina) and the final product eluted by using 2.0 mL of 20% ethanol/ phosphate buffer (pH-4.5). The radiochemical purity was determined by radio-HPLC and endotoxin test was done using Endosafe-PTS cartridge for volunteer injections. Around 5-6 mCi of [18F]-FMZ was injected intravenously into volunteers and the dynamic scan was acquired on simultaneous PET-MRI (Siemens Biograph) for 90 minutes. The images were processed in P-MOD (neuro) and time-activity curve was created for all regions. Results: The labeling was found to be maximum by using K18F/kryptofix complex in the DMF at 160°C for 30 min. An equimolar concentration of [K/K2.2.2]+18F-/precursor was used and the incorporation of 18F in the flumazenil was found to be 19 ± 3%. The combination of C18 and alumina cartridges gave the highest yield (15 ± 2 %) as compared to 1-2% by the other two combinations. The radiochemical purity was 95 ± 3 % as evaluated by Radio-HPLC with retention time at 15.4 ± 0.3 min (n = 10). This method was adopted for automation and a sequence (for FX2N) was created by us to run the protocol for clinical production of the [18F]-flumazenil. The endotoxin levels were below the 175/EU/dose. The regional time activity the curve showed the highest uptake at 12 min in neocortical regions, followed by cerebellum, thalamus and putamen, and low uptake in the brain stem regions (pons and medulla). Conclusions: [18F]-flumazenil was synthesized with higher radiochemical purity and a simple automated method for clinical use. The pons can be used as a reference region to calculate accurate values for the binding potential.


   PP7: Radiolabeling, characterization and bio-distribution studies of 99mTc-DOTA-ranatensin peptide analogue for targeting bombesin receptors in prostate cancer Top


Ajay Kumar, Raunak Varshney, Anil K. Mishra, Amritjyot Kaur, Sarika Sharma, Shalini Chopra, Baljinder Singh

PGIMER, Chandigarh, India.

Aim: Gastrin-releasing peptide (GRP) receptors (GRPr) and Neuromedin B (NMB) receptors (NMBr) are frequently over-expressed in human prostate cancer. Existing SPECT/PET molecular imaging probes, target only one subtype of bombesin receptors i.e. GRP or NMB. However, it is known that GRP and NMB receptors co-exist in a significant proportion in patients with PCa. The aim of the present study was to optimize the radiolabeling of DOTA-ranatensin peptide with 99mTc and characterization of the radiolabeled conjugate followed by in vitro and bio-distribution studies for targeting GRP/NMB receptors. Materials and Methods: Freshly eluted 99mTc from 99Mo-99mTc generator was used to radiolabel ranatensin peptide analogue (DOTA-6Ahx-Aib-Gln-Trp-Ala-Val-Gly-His-Leu-Met-NH2) procured from link Biotech. To obtain maximum radiolabeling efficiency of 99mTc-DOTA-ranatensin, various reaction parameters like pH (4.0, 5.0, 6.0, 7.0, 8.0, 9.0), amount of stannous chloride anhydrous (5 μg, 10 μg, 20 μg, 50 μg, 100 μg), conjugate concentration (10 μg, 25 μg, 50 μg, 100 μg, 150 μg, 200 μg) and heating time (10 min, 20 min, 30 min) of reaction were optimized. The labeled 99mTc ranatensin peptide was purified using C-18 cartridge. The radiolabeled product was characterize by MALDI–TOF. The RCP of labeled radioconjugate was analyzed by Instant thin layer chromatography (ITLC). In vitro stability, serum stability, lipophilicity, plasma protein binding of the radioconjugate was investigated. The bio-distribution study was performed in female Wistar rats (n=12, age=6-8 weeks, wt.=150±10 g). Results: The maximum radiolabeling yield was obtained at pH=8, amount of sncl2=10 μg, conjugate concentration= 100 μg, incubation time=20 min. The radiolabeling yield and RCP of 99mTc-DOTA-ranatensin peptide was 70.0±5.0% and > 90.0% respectively. The molecular mass of the 99mTc-DOTA ranatensin peptide analogue was characterize by molecular ion peak at m/z =1677.233 [M+Na-3H+], cal.= 1657.02. The compound was stable up to 6.0 h at room temperature and 4.0 h in serum. The radioconjugate was hydrophilic (Log P = -0.26 ± 0.66) and plasma protein binding was 39.7 ± 2.05%. The 99mTc-DOTA ranatensin showed rapid blood clearance and excretion through kidneys. Negligible uptake (<0.1% ID) was observed in the various organs of the animal body. Conclusion: The DOTA-ranatensin peptide analogue was successfully radiolabeled with 99mTc and characterized by mass spectroscopy and showed reasonably high radiolabeling yield and radiochemical purity. In view of encouraging quality tests, characterization, biodistribution studies, the radiolabeled conjugate can be taken up confidently for further pre-clinical evaluation to prove its translational relevance in clinical scenario.


   PP8: Quantification of SERT transporter and serotonergic (5HT1A) receptor binding with [11C]-N-BMPP in CMS rat brain Top


Niharika Singh, Upasana Sahu, Parul Mittal, Krittika Zutschi, Anil Kumar Mishra, Puja Panwar Hazari

INMAS, Delhi, India.

Aim: 5-HT1A receptor and SERT transporter quantification in CMS rat brain was done to assess the role of these receptors in depression. A new Carbon-11 ligand, [11C]-N-BMPP can be used in vivo allowing the quantification of both postsynaptic receptors and somatodendritic auto receptors. This could be useful in facilitating research regarding the impairment of 5-HT1A functions. Moreover, changes in the number of receptor and affinity can be taken into consideration of synaptic 5HT concentration. Materials and Methods: For ex vivo radioligand binding in non anaesthetized rats, the rats were pretreated with drug and injected with radioactivity. After this, euthanasia was done. The brains were removed and kept on ice during dissection time. Radioactivity was measured. Extracellular 5-HT was monitored by in vivo microdialysis of some of the brain tissues. For this, the second set of experiment was done by collecting dialysate samples and were assayed for 5HT by high performance liquid chromatography. For performing in vivo PET scanning of rats [11C]-N-BMPP was administered via tail vein to rats. The PET scan was performed and reported. Results: Ex vivo radioligand binding SERT Transporters in non anaesthetized rats was found to be relatively high in cortex. The in vivo microdialysis of some of the brain tissues showed that the hippocampal variation was higher than the prefrontal cortex. The in vivo PET scanning of anaesthetized rats using [11C]-N-BMPP outlined that there is pseudospecific binding in the cerebellum due to the presence of SERT transporter. Conclusion: Only high levels of 5-HT will have a significant effect on PET studies with [11C]-N-BMPP. Moreover, [11C]-N-BMPP proved to be a potent radioligand having higher binding affinity toward SERT Transporter. Further studies are required to corroborate the expression of 5HT in flouxetine treated rats.


   PP9: Development and standardization of a new method for the detection of radiochemical and chemical purity of the positron emission tomography radiopharmaceuticals Top


Raman Kumar Joshi, Gopinath R. Sridhar, Pardeep Kumar, Rose Dawn Bharath

NIMHANS, Bengaluru, Karnataka, India.

Introduction: In Radiopharmacy the Quality control is very important and the foremost step before considering a molecule is good for the patient administration. Objective: To assess the Enantiomeric impurity by HPLC in the 11C-Methionine preparation. Methods: We produced 11C at our on-site cyclotron (GE Pettrace 860) by bombarding nitrogen gas containing 1% oxygen with protons at current 30 μA for 20 min {14N[p, α]11C } to transfer 1200 ± 50 mCi of 11C-CO2 in to the FX2C module. In module, 11C-CO2 was reacted with hydrogen gas at 350 °C in presence of nickel catalyst. 11C-CH4 is trapped on Carboxen (60-80 mesh) under N2 liq. cooling at -75°C whereas un-reacted 11CO2 and H2O vapors were trapped on the traps (ascarite and sicapent respectively). 11C-CH4 released and underwent iodination to form 11CH3I at 740 0C which recirculated in the loop and trapped on porapak trap at room temperature until reached to maximum activity. After reaching the maximum activity it is released from the porapak trap at 190 0C with Helium flow through V17 directly over the unconditioned C18 sep-pak cartridge containing precursor L-homocycteinethiolactone hydrochloride. 11CH3I reacted with the precursor to form 11C-methione which was eluted with 0.05 sodium dihydrogen phosphate (5 mL). Radio-TLC was performed on TLC scanner with a speed of 2 cm/min using Water/Ammonia/Methanol (1:5:15).The HPLC (Dionex, ICS- 5000+, +, California. USA), having UV/Vis and radio-detector was done using mobile phase consists of acetonitrile (0.1% trifluoroacetic acid) and water (0.1% trifluoroacetic acid), starting with 5% acetonitrile (0-5 min), 5% to 100% acetonitrile (5-20 min), then100% acetonitrile (20-25 min) and again at 5% acetonitrile (25-30 min). For 11C-methionine HPLC two peaks of L- and D-isomers were seen and were confirmed by the retention times of standards L- and D-Methionine. The Chemical impurities were analyzed by Gas chromatography (GC Scion 436 GC, Netherlands) having flame ionization detector (FID). The Endotoxicity was checked in the portable test system (Endosafe® nexgen-PTS™, United States). Results: L- and D-isomers were identified by HPLC with UV and radiometric detectors. The percentage of L-11C-methionine was 89 ± 5% at 12 ± 0.6 min and D-11C-methionine was 3.5 ± 0.5% at 5.5 ± 1.5 min. The retention time of methyl iodide was 16.4 ± 0.5 min. The Ethanol content was <100 ppm in the final preparation. The L-Homocysteine thiolactone was found < 0.2 mg/V. The product was found to be endotoxin free. Radionuclide purity was > 99% with clear 511 KeV energy peak. Half life found was 20.2+/-0.4 min. Conclusion: L-11C-methionine was sterile and used for glioma patients.


   PP10: 99mTechnetium labeled S-alkylated N-acetyl cysteine conjugated to DTPA for targeted tumor imaging Top


Parul Mittal, Upasana Sahu, Niharika Singh, Anil K. Mishra, Puja Panwar Hazari

INMAS, Delhi, India.

Objective: Transport of amino acids plays a vital role in cell survival. LAT1 uses intracellular amino acid concentrations generated by ASC2 to adjust essential amino acid levels for metabolic needs and signaling to mTOR pathway. ASC2 and LAT1 both showed threefold upregulation in cancerous tissues. NAC is precursor for glutamine and an important intracellular antioxidant that prevents damage caused by reactive oxygen species. Sulfhydryl (thiol) group (SH) of cysteine serves as proton donor for synthesis of GSH. Cancer cells are dependent on external source of glutamine and have increased ASCT2 and glutaminase activity. Thus, it can be potential target as it supplies essential amino acids to tumor cells. Thus N-acetyl cysteine was conjugated to DTPA through S-alkylation for targeted tumor imaging. Methods: To a solution of DTPA (1.0 mmol) dissolved in DMF were added triethylamine and the mixture was stirred at 40°C. After 30 min, N-acetylcysteine was added and the reaction was allowed to proceed for 48 hours at 65°C and then 48 hours at room temperature. DTPA-bis-NAC was radiolabeled with 99mTc. The radiolabeling yields of 99mTc DTPA-bis-NAC were determined by ascending thin layer chromatography on ITLC. In vivo and in vitro evaluation of DTPA-bis-NAC was done on A549 (human tumor cell line) xenografted nude mice. Results: DTPA-bis-NAC was successfully radiolabeled with 99mTc with radiolabeling efficiency of ~95.6% and then subjected to purification to get 99.5% radiochemical yield. Transchelation test indicated the stability of the radiocomplex. Effectiveness of DTPA-NAC in vitro was assessed by cell uptake assays in tumor cell lines (A549) and in vivo by biodistribution studies with athymic mice bearing A549 cell lines, which showed high tumor uptake. Tumors grafted were readily identifiable in gamma images, maximum uptake of compound was observed in tumors. Also it yield the pharmacokinetics of the radiotracer and was found that there is rapid systemic clearance and a significant accumulation in kidney indicating complex excretion through renal routes. Conclusion: Preliminary in vitro and in vivo studies support the potential of 99mTc DTPA-bis-NAC on the way of becoming a successful 99mTc-radiolabeled tumor-targeted imaging agent.


   PP11: Design, synthesis and preclinical evaluation of TE3A macrocyclic system conjugated to N-acetyl cysteine for theranostics Top


Upasana Sahu, Parul Mittal, Niharika Singh, Anil K. Mishra, Puja Panwar Hazari

INMAS, Delhi, India.

Aim: We aimed to design a N-substituted 14 membered cyclam macrocycle with the construction of a framework, which has optimum cavity size to bind with metals in +2 and +3 oxidation state. The complexes of TE3A analogues have greater stereochemical rigidity than TE3A itself. Thus we have synthesized a new bifunctional chelating system for conjugating N-acetyl L-Cysteine for 64Cu and 44Sc labeling. The synthesized conjugate shows promising application for LAT1 and ASC system for theranostics. The synthesized molecule targets the enhanced amino acid uptake and NAC was attached via S-alkylation to prevent its incorporation in the nondesired protein/nonprotein segments. Materials and Methods: The first step involves reaction of 1, 4, 8, 11-tetraazacyclotetradecane with tert-Butyl bromoacetate affording the trisubstituted cyclam, which was conjugated with alkylated product of chloroacetyl chloride and N-acetyl cysteine to give the tetraaza-substituted product. The resulting compound was obtained by carrying out the boc deprotection using trifluoroacetic acid in Dichloromethane. The structures of these ligands and their complexes with copper and scandium were confirmed by spectroscopic methods of analysis like HRMS and NMR spectroscopy. Results: The TE3A-NAC conjugate was successfully synthesized and complexed with copper and scandium. The cold complexes of TE3A-NAC were subjected to invitro evaluation for its toxicity studies. The complexes are shown to have antitumor activity on A549 cells. Conclusion: A new chelate incorporating N-acetyl cysteine has been synthesized for imaging. The conjugate displays considerable thermodynamic and kinetic stability in vivo. Preliminary in vitro and in vivo studies support its potential on the way of becoming a potential theranostic agent.


   PP12: Targeting brain receptor via DTC based radioligands-design, synthesis and biological evaluation of 99mTc-FCM (DTC) as potential single-photon emission computed tomography brain imaging agent Top


Vishakha Chaudhary, Shubhra Chaturvedi, Anju, Rupesh Kumar, Anil Kumar Mishra

INMAS, Delhi, India.

Introduction: The aim of this study is to establish a novel brain receptor imaging agent for the early diagnosis of neurological disorders by targeting the 5-HT1A receptor. The key requirements for the development of target specific neuroimaging agents are high selectivity, affinity and blood brain barrier permeability. For the high selectivity methoxy phenyl piperazine is selected as it is a selective and potent antagonist of 5-HT1A receptors and ferrocene as an organometallic moiety is introduced to make it permeable through blood brain barrier. The metallocene not only make it lypophylic for membrane translocation but also facilitates the localisation and bistribution of the conjugate in the cytoplasm. Therefore in present work, we have synthesized ferrocene-MPP analogue which was conjugated to DTC and labeled with 99mTc to act as SPECT imaging agent for brain imaging. Materials and Methods: The precursor N-(2-Methoxyphenyl) piperazine (MPP) was synthesized by appending N-bocbromoethylamine with 2-Methoxyphenylpiperazine (MPP) using substitution reaction in the presence of base. After acidic (TFA/DCM) deprotection the obtained amine was conjugated with ferrocenecarboxaldehyde through Schiff base formation and reduced in situ using sodium borohydride (NaBH4). Introduction of chelator for radiolabeling with 99mTc was done by conjugating the precursor with carbon disulphide. The compounds were purified by column chromatography and characterized by spectroscopic methods like NMR, HRMS and UV. Glide docking was performed for the ligands from schrodinger software using 3d4s as PDB to know the binding affinity towards targeted receptor protein. Radiolabeling parameters were optimized. To study the blood clearance pattern of 99mTc-FCM-DTC blood kinetics experiments was performed in rabbit. Results: Quantitative yield of the compound and intermediate are MPP-Boc, MPP-NH2, FCM, FCM-DTC was 80%, 80%, 60% and 50% respectively. The mass of the compounds MPP-Boc (336(M+H)+), MPP-NH2(236(M+H)+), FCM (434(M+H)+), FCM-DTC (508(M-H)+).The compounds were also characterized by NMR. 93% radiolabeling was observed with SnCl2 as reducing agent. The G score of the docking was found -6.79 which shows that ligand can be potential candidate for targeting 5-HT1A receptor. Blood clearance experiment shows a rapid washout of 99mTc-FCM-DTC during the initial time periods followed by a slow release afterwards. Conclusion: In conclusion, the present study is attempt to establish a highly selective and BBB permeable DTC based radioligand as a potential brain receptor imaging agent. This work also facilitate the bio-organometallic conjugation of ferrocene with MPP to make a BBB permeable radioligand.


   PP13: In-house standardization of radiolabelling of antitubercular drug ethambutol with 99mTechnetium Top


Satyam Kumar, Geetanjali Arora, Nishikant A. Damle, Chandrasekhar Bal, Madhavi Tripathi, Bisakh Bhattacharya, Piyush Ranjan, Meivel Angamuthu, Sneha Prakash, Naresh Kumar

AIIMS, New Delhi, India.

Aim: Ethambutol (EMB) is a standard first line antitubercular drug that inhibits mycolic acid synthesis in the cell membrane. Very few clinical studies have been performed with this drug so far. The labelling technique used is mainly kit-based while a few studies have used in house preparations. Since diagnostic radiopharmaceuticals need to have a labelling efficiency of > 90%, we aimed to standardize the in-house labelling technique followed by in vitro quality control. Materials and Methods: HPLC grade Ethambutol was procured from Merck (KGaA, Darmstadt, Germany). All other chemicals used were analytical grade. Labelling was performed by reduction method adapted from the kit-based methods described by Kartamihardja et al (2017). Briefly, mannitol was added to EMB followed by the addition of pyrophosphate, stannous chloride and 99mTc pertechnetate. The mixture was then incubated at room temperature. Labelling efficiency (LE) was checked by paper chromatography using Whatman paper 1 as stationary phase and acetone as mobile phase. The method was standardized for amount of EMB, mannitol, and stannous chloride. Results: With change in the amount of EMB (1-5 mg) the LE increased upto 3 mg (>95%). LE remained constant 4 mg (>95%) and decreased slightly to 89% at 5 mg. With change in amount of mannitol (3-15 mg), the highest LE was obtained at 5 mg becoming almost constant thereafter. Similarly, highest LE was obtained at 300 ug of SnCl2 (200-1000 ug) and 2 mg pyrophosphate (1-5 mg). With the standardized parameters the LE was consistently >95%. In vivo studies in patients with the labelled antibiotic consistently showed increased uptake in known tuberculous lesions. Conclusion: The parameters standardized for labelling were 5 mg mannitol added to 3-4 mg EMB followed by the addition of 2 mg pyrophosphate, 300 ug SnCl2 and 25 mCi of 99mTc pertechnetate incubated for 30 min at room temperature. 99mTc labelling of ethambutol was successfully standardized in-house and satisfactory synthesis of this radiopharmaceutical is easy and consistent.


   PP14: Assessment of correlation between radioactivity delivered from medical cyclotron on radio-labelling yield of 18F-DOPA Top


Munish Kumar, Nivedita Rana, Rakhee Vatsa, Karan Tanwar, B. R. Mittal

Department of Nuclear Medicine, PGIMER, Chandigarh, India.

Aim: Fluro-3,4-dihydroxyphylalnine (18F-DOPA) can be produced via both electrophilic and nucleophilic reaction, each having their advantages and disadvantages. The aim of present study is to assess the correlation of F-18 radioactivity delivered from Medical Cyclotron (MC) on radio-labelling yield. Materials and Methods: F-18 was produced using O-18 (p,n) reaction in MC and transferred to cassette based automated synthesis module (M/s Ora, NEPTIS). F-18 was radio labeled via nucleophilic substitution reaction using Ester based precursor. Meta-chloroperoxybenzoic acid (mCPBA) was used for oxidation reaction and ethanolic HCL for reduction. Purification was done by C18ec, HRP, C-18 was and alumina cartriages at various steps. After the synthesis time of 1 hr 33 mins, final product of F-DOPA was obtained. The activity delivered from MC to synthesis module and corresponding activity of F-DOPA was noted in all the productions done from April 2017 to August 2019. The percentage radio-labelling yield of F-DOPA was calculated by dividing the activity of F-DOPA produced by activity of F-18 delivered. Pearson's correlation coefficient was calculated between radioactivity delivered from MC and radio-labeling yield. Results: In total fifty seven successful productions were done in period of twenty months. The minimum and maximum activity transferred was 920 mCi and 1302 mCi respectively. Range of percentage yield was 3.59-10.53%. However, the minimum and maximum activity delivered did not correspond to minimum and maximum yield. Yield corresponding to 920 mCi was 6.51% and for 1302 mCi was 6.82%. Also the Pearson correlation coefficient was found to be 0.014, suggesting no correlation. Conclusion: So it can be concluded that there is no correlation between activity delivered and yield, implying F-DOPA production is dependent on number of factors, and the activity produced cannot be estimated according to the activity delivered.


   PP15: Noninvasive assessment of wound-healing angiogenesis with multimeric peptide conjugate (99mTc-laminin-cRGD) Top


Meenakshi Saklani, Rashi Mathur, Anil K. Mishra, Raunak Varshney

INMAS, Delhi, India.

Aim: The ability to depict wounds for the purposes of assessing severity, healing potential and to define the correct treatment for all wound types has largely depends on visual inspection by the experienced clinician only. Advance in emerging techniques include broader evaluation of the wound bed and the quantification of angiogenesis and epithelialization, which is the critical steps in the healing process. Imaging technologies could assess wound severity, healing potential and healing progress in a rapid, objective and noninvasive manner. However only optical technologies are currently in progress for noninvasive wound assessment. Angiognesis plays a crucial role in wound healing by forming new blood vessel from preexisting vessels by invading the wound clot. Growth factor, cytokines and cell adhesive molecule like Laminin and integrin αvβ3, plays key roles in regulating the growth of new blood vessels. RGD is the most investigated adhesive peptide known to interact with a number of cell surface receptors belonging to the αvβ3 integrin and subtypes. Similarly, Laminin based peptide strongly promote angiogenesis and protease activity via integrin receptor. The rationale of this study was to develop modified 99mTc-laminin-cRGD as SPECT Imaging probe to access the wound healing progress noninvasively by targeting angiogenesis. Materials and Methods: The Laminin and cRGD peptide was synthesized by solid phase peptide synthesis through Fmoc chemistry on rink amide resin and chlorotrityl chloride resin respectively. After swelling of resin in dry DMF the F-moc group of resin was deprotected by using 20%(v/v) piperidine solution in rink amide resin and Cl-trityl chloride resin was directly couple with first amino acids. First amino acids was added with HOBT & DIC in dry DMF. All amino acid was coupled in same protocol until the final peptide was achieved. After completion of amino acid coupling the free N-terminal of laminin and c-RGD peptide was coupled through linker. This conjugated peptide cleaved from resin using TFA cocktail solution having scavenger. The conjugate was radiolabeled with 99mTc in aqueous solution at pH 6.5-7.5. Results and Conclusion: The synthetic yield of multimeric peptide was ~62% yield. Peptide was purified by HPLC and characterized by molecular ion peak at 779.51 [M+ H]+ and 821.58 [M+ H]+ in Mass Spectroscopy. In hemolytic studies of multimeric peptide, maximum percentage of erythrocytes lysis was observed to be 4.03 which indicate peptide was stable in blood and nontoxic.The conjugate binds with 99mTc with high specific activity and efficiency (97.4%). The stability in serum indicated that 99mTc remained bound to the drug upto 24 h. Further to evaluate the angiogenic effect to monitor the wound progress is under progress. Non-invasive imaging technologies could prove objective assessment modalities and promising advancement in wound assessment, however require further validation.


   PP16: In-house radiolabelling and quality control of 99mTc-ceftriaxone and 99MTC-ciprofloxacin Top


Satyam Kumar, Geetanjali Arora, Nishikant A. Damle, Chandrasekhar Bal, Madhavi Tripathi, Meivel Angamuthu, Sneha Prakash, Naresh Kumar

AIIMS, New Delhi, India.

Aim: We hypothesize that specific antibiotics if radiolabeled successfully with a diagnostic radionuclide, could have a theranostic value. Very few studies are available with the in vivo use of 99m Tc- Ceftriaxone in infection imaging. In the present study, ciprofloxacin and ceftriaxone were radiolabeled with 99mTc followed by in vitro quality control, as an initial step before using these tracers in vivo. Materials and Methods: HPLC grade ciprofloxacin and ceftriaxone was procured from Merck (KGaA, Darmstadt, Germany). All other chemicals used were analytical grade. Labelling was performed by reduction method. Briefly, 100 ug stannous chloride was added to 2 mg ciprofloxacin followed by the addition of 15-30 mCi 99mTc-pertechnetate. The mixture was then incubated at room temperature for 30 min. Labelling efficiency (LE) was checked by paper chromatography using Whatman paper 1 as stationary phase and methyl-ethyl ketone as mobile phase. Similarly, 50 ug stannous chloride was added to 30 mg ceftriaxone followed by the addition of 15-20 mCi 99mTc-pertechnetate. The mixture was then incubated at room temperature for 30 min. LE was checked by paper chromatography using Whatman paper 1 as stationary phase and acetone as mobile phase. Results: Total number of syntheses conducted was 10 each for ciprofloxacin and ceftriaxone. Mean LE for ciprofloxacin was 97 ± 1.49% and for ceftriaxone was 96.95 ± 2.82%. Since diagnostic radiopharmaceuticals need to have a labelling efficiency of > 90%, we could consistently radiolabel both the antibiotics with LE>95% in our laboratory set up. Conclusion: Both ciprofloxacin and ceftriaxone could be successfully radiolabeled with 99mTechnetium in-house.


   PP17: Computed tomography contrast not superfluous, rather informative on adaption of a multiphase computed tomography acquisition protocol for routine Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography Top


Abbas Ali, Sachin Tayal, Vikrant Kumar, Arun Gandhi

Research Centre, Kailash Cancer Hospital, Vadodara, Gujarat, India.

Aim: To complement the Positron emission tomography-computed tomography (PET-CT) imaging by optimizing contrast infusion timing and multiphase CT imaging. Materials and Methods: Head and neck cancer patients prescribed for PET-CT scan were evaluated under PET-CT machine of GE {Discovery STE,16 slice CT scanner and Bismuth Germinate Oxyorthosilicate (BGO) crystal}. Patients had fasted for at least 5-6 hours prior for PET-CT study and all possible contraindications to inject contrast was ruled out. Written informed consent was obtained from each patient. The patients were then injected with F-18 Fluorodeoxyglucose (FDG) and made to sit in post injection room in a calm position. Scan was acquired after 45 minutes of injection with the use of multiphase CT protocol in head and neck cancer patients as follows [Table 1] with special emphasis on arterial phase CT being acquired in helical mode, having slice thickness of 1.25 mm, pitch 0.938:1, speed of rotation 9.37 mm/rotation. An average dose of 60-70 mL intravenous contrast (Contrapaque 240; iodine concentration of 240 mg/mL) was used for an adult patient with a flow rate of 2.3-2.4 mL/sec with scanning volume covering the area from the skull base to the thoracic inlet in the cephalo-caudad direction. The patients were lying in the supine position. Results: In the head and neck cases, intravenous contrast agents help increase the sensitivity for detection of pathological lesions and improves the accuracy of lesion characterization. It was observed that the flow rate should not be less than 2.0 mL/sec for adequate enhancement. Conclusion: Indeed, this type of protocol can lead to mis-registration due to repeated hands up and down position but proper counselling before acquisition can help us achieve a good quality image. With the adaption of multiphase CT protocol in multislice CT scanners of today's PET-CT we can achieve a complete diagnostic information in much lesser time with one PET-CT study and help reduce the cost of investigation.
Table 1: Multiphase CT protocol in head and neck cancer patients

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   PP18: Effects of absolute and background activity on measurements of volume-of-interest and standard uptake values in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography image: A phantom study Top


Srikanth Saminathan, Manish Ora, S. C. Kheruka, S. Gambhir

SGPGIMS, Lucknow, Uttar Pradesh, India.

Introduction: The success of cancer treatment requires accurate tumor measurement and that allows the clinician to make the best therapeutic decision. 18F-FDG PET/CT has become a standard tool to evaluate the primary tumor and assess the treatment response. Volume-of-Interest (VOI) is a tool that determines the volume of tumors in cubic centimeters based on the concentration of radioactivity. Standard Uptake Values (SUVmax) is expedient parameter to semiquantitative evaluate the metabolism of the tumor. However these parameters depend upon various factors like absolute activity in the VOI, volume of it and background activity. Aim: The aim of this study was to analyze the effects of absolute, background activity and size of lesion on measurements of VOI and SUVmax on PET/CT. Materials and Methods: Esser Flangeless Phantom and inserts were filled with 18F-FDG at variable concentrations. PET/CT was performed using the same parameter on mCT64 Biograph (Siemens). TrueD software was used to draw VOI, measure SUVmax and determine the volume of the cylindric inserts. The same technique was used to calculate VOI and SUVmax for various concentrations of the activities. These values were compared with original volumes. Results: Volumes measured with the VOI technique were similar to the actual volumes of cylinders in all concentrations (no statistical difference, P < 0.05).There was no effect of absolute activity or surrounding activity on volume measurement. In all dilutions measured SUVmax were same, but it was least for the smallest volume. Increasing both absolute and background activity in the same ratio had no significant effect on the SUVmax. As the size and ratio of the absolute activity concentration of the cylinder decrease measured SUVmax also gradually decreases because of partial volume effect. Conclusion: In the 18F-FDG PET/CT phantom study, the VOI technique was able to determine volumes of activity mimicking tumor in the insert as small as 1.9 cm3. Absolute or background activity has no significant effect on measurement of VOI or SUVmax calculation in larger diameters. A significant partial volume effect was noted only in smallest diameter (1.9 cm3).


   PP19: Custom made prosthesis measurements based on imaging and comparison with histopathological examination for limb tumors Top


G. K. Rangarajan, R. Krishnakumar

Cancer Institute (WIA), Chennai, Tamil Nadu, India.

Aim: To study the usefulness of bone scan measurements in planning the Custommade Prosthesis (CMP) in Limb salvage surgery. In this context we perform imaging like Nuclear Bone scan (BS) Magnetic Resonance Imaging Scan (MRI scan) and scanogram. Materials and Methods: About 70 patients (both males and females) with limb tumors who were fit for LSS have been taken up for this study. Few of them have gone amputation/disarticulation. Bone scan and MRI was done in all these patients for custommade prosthesis measurements and compared with final HPE report. Results: A spectrum of bone tumors like Ewing's sarcoma, Osteosarcoma, and Osteoclastoma were included. The bone scan and MRI were done in all these patients for planning the CMP. Limb salvage surgery is one of the innovative procedures practiced in our center. Bone scan has the advantage of whole body survey and in finding the skip lesion and distant metastasis. MRI will display local extent and marrow involvement. After bone scan and workup, patient underwent neoadjuvant chemotherapy before surgery - generally 3-4 courses over a period of 2 3 months. The bone scan and MRI measurements were correlated with measurements given in post-operative HPE specimen. In 60/70 patients (86%), our prediction of dimension of lesion has correlated with final HPE report. In 10/70 patients (14%), final HPE revealed a lesion more than our predictions probably indicating non response to (NACT) Neo Adjuvant Chemotherapy/progression. So in this paper the prosthesis is planned based on the initial tumor length from the bone scan and MRI and concordance with HPE measurements estimated. Conclusion: So the carry home message is we have highlighted fact that bone scan / MRI measurements help in majority of patients (86%) for CMP measurements.


   PP20: Development and characterization of 99mTc labeled N-acetyl neuraminic acid for its application in in vivo imaging of cancer: A preclinical study Top


Ravi Ranjan Kumar, Vijayta Dani Chadha, Devinder Kumar Dhawan

Centre for Nuclear Medicine, Punjab University, Chandigarh, India.

Aim: In the present study, N-acetyl neuraminic acid (Neu5Ac), a sialic acid was labeled with radionuclide 99mTc and the optimization of the radio-complex as well as its bioevaluation was performed. Materials and Methods: The radiolabeling of n-acetyl neuraminic acid with 99mTc was standardized using stannous reduction method. The radiochemical purity analysis and physicochemical characterization of the radiocomplex was assessed using ITLC, HPLC, Paper electrophoresis and ESI–MS analysis. Further, the radiocomplex 99mTc-Neu5Ac was bio evaluated for its tumor targeting potential by performing its biodistribution in colon tumor bearing rats and scintigraphic imaging. Results: Radiolabeling of Neu5Ac with 99mTc was obtained with a maximum labeling yield of 93.6% and was confirmed by ITLC, mass spectra (ESI-MS) and HPLC. The resulting radiocomplex showed hydrophilic properties and highly stable up to 8 hrs. at room temperature in rat serum and saline. The protein binding assessed in plasma was found to be <50%. Blood clearance of radiocomplex showed biphasic nature. Biodistribution studies of the radiocomplex revealed highest accumulation (%ID/g) in kidneys, followed by liver and spleen in normal as well as tumor bearing rats. The most significant finding of the study was higher colon to muscle % uptake ratio in colon tumor bearing rats when compared to normal control rats. In-vivo imaging also reflected the same pattern of radiotracer uptake as observed in bio- distribution studies. Conclusions: Neu5Ac was successfully radiolabeled with 99mTc and exhibited selectivity for neoplastic colon tissue owing to hypersialylation and thus has the potential to be exploited further for its role in tumor imaging.


   PP21: Targeted delivery of 99m Tc-folic acid to folate receptor expressing tumors Top


Swapna Nabar, Krutika Kadam, Avik Chakraborty, Yogita Pawar, Sutapa Rakshit, Sharmila Banerjee

RMC, Mumbai, Maharashtra, India.

Aim: To optimise 99mTc labeling of Folic acid and use 99m Tc-Folic acid as a diagnostic agent for Folate receptor expressing tumors in mouse model. Materials and Methods: Folic acid was radiolabeled with 99mTc using Stannous Tartarate as a reducing agent. Radiolabeling was optimised by varying concentration of Folic acid, Stannous Tartarate, pH and incubation time. The RCP of 99m Tc-Folic acid was checked by paper chromatography. The stability of 99mTc- Folic acid was checked in human serum and with DTPA challenge test and was found to be stable. In-vitro uptake studies were done by incubating 99m Tc-Folic acid with Folate receptor expressing B16F10 murine Melanoma cells (1x105). In-vivo biodistribution studies of 99mTc- Folic acid were done in B16F10 Melanoma tumor model developed in-house in C57BL/6 mice. Gamma imaging studies were done post injection of 99mTc- Folic acid in B16F10 Melanoma tumor model. Results: The RCP of 99m Tc-Folic was ≥90% which was stable in human serum and when subjected to DTPA challenge test. In-vitro uptake of 99m Tc-Folic acid was 30 % at two hours when incubated with B16F10 murine Melanoma cells (1x105) which decreased to 7% when cold Folic acid was added. In vivo biodistribution studies in B16F10 Melanoma tumor model showed tumor uptake of 8% at two hours post injection. Gamma imaging studies showed localisation of 99m Tc-Folic acid in B16F10 Melanoma tumour developed in C57BL/6 mice. Conclusion: Folic acid was optimally radiolabeled with 99mTc having RCP > 90%. Preliminary in-vivo studies in Folate receptor expressing tumor model showed tumor uptake of 8%, hence may be used in future as a diagnostic agent for detecting Folate receptor expressing tumors. In-vitro studies showed that cold Folic acid bound to the folate receptors competitively and inhibited the cell binding of radiolabelled folate in the cells. This shows that 99mTc-FA is not interfering with the cell binding efficiency of Folic acid to the folate receptors.


   PP22: Targeted tumor therapy with radiolabeled DNA intercalator: An attempt to prepare and evaluate the potential of 177Lu-acridine Top


Subhajit Ghosh, Tapas Das, Shishu K. Suman, Haladhar D. Sarma, Ashutosh Dash

BARC, Mumbai, Maharashtra, India.

Aim: Acridine is a well-known DNA intercalator and thereby gets easily incorporated into DNA. Uncontrolled and rapid cell division being one of the primary characteristics of the tumor cells, it is expected that acridine or its suitable derivatives will have preferential accumulation in the tumorous lesions. Therefore, acridine derivatives labeled with suitable therapeutic radionuclide may have potential as agents for targeted tumor therapy. Working in this direction, an attempt was made to radiolabel 9-aminoacridine with 177Lu and study the potential of 177Lu-acridine complex as an agent for targeted tumor therapy. Materials and Methods: 9-aminoacridine was coupled with p-NCS-benzyl-DOTA in aqueous alkaline medium at room temperature and the conjugate was purified by repeated solvent extraction using chloroform and water. The acridine-DOTA conjugate was characterized by standard spectroscopic techniques, such as, FT-IR, 1H-NMR and mass spectrometry. Radiolabeling of the conjugate was carried out by incubating the conjugate (10 mg, 13.40 μM) with 177Lu (1 mCi, 37 MBq) in ammonium acetate buffer (pH 5, 1 M) at 100 °C for a period of 45 min. The radiolabeled conjugate was characterized by HPLC using water and acetonitrile mixed with 0.1% trifluoro acetic acid as the mobile phase employing gradient elution technique. Various radiolabeling parameters were optimized to maximize the radiolabeling yield of 177Lu-acridine complex. The stability of the radiolabeled preparation was studied by incubating the preparation in normal saline as well as in human blood serum. Biological behavior of the 177Lu-acridine complex was studied both in-vitro and in-vivo using Raji cell line and fibrosarcoma tumor bearing Swiss mice, respectively. Results: 177Lu-acridine complex was obtained with ~100% radiochemical purity under the optimized reaction conditions involving incubation of 1.5 mg/mL of the conjugate with 177Lu at 100 °C for 45 minutes. The complex maintained a radiochemical purity of >85% in normal saline till 6 d post-preparation and >70% in human blood serum till 2 d after preparation. In-vitro cellular study showed appreciable uptake of the radiotracer in the Raji cells. Biodistribution study revealed significant tumor accumulation [(9.98±0.13)% IA in per gram of tumor] of the radiotracer within 1 h post-administration along with distribution of the activity in other non-target organs such as, blood, liver, GIT, kidneys etc. The non-accumulated activity showed gradual clearance through renal route. Conclusion: The present study indicates the potential of 177Lu-acridine as an agent for targeted tumor therapy. However, further detailed evaluation of the agent is warranted to explore its actual potential.


   PP23: 68Ga-labeled peptide probe for targeting HER2 receptor expression in breast cancers Top


Amit Kumar Sharma, Kusum Vats, Tapas Das, Drishty Satpati, Ashutosh Dash

BARC, Mumbai, Maharashtra, India.

Aim: Human epidermal growth factor receptor-2 (HER2) is a crucial biomarker for breast cancer and associated with poor prognosis. HER2-targeted molecular probes therefore have significant implications in imaging and therapy of breast cancers. Radiolabeled antibodies (trastuzumab, pertuzumab) have been developed for targeting HER2 receptor expression in breast cancers, but long blood circulation time limits their effectiveness. Here we have attempted to develop a 68Ga-labeled peptide probe as a HER2 targeting tracer. Materials and Methods: The peptide, DOTA-PEG4-Gln-Asp-Val-Asn-Thr-Ala-Val-Ala-Trp (DOTA-PEG-A9) was synthesized using standard protocols of Fmoc solid phase peptide chemistry and purified using semi-preparative HPLC. 68Ga-labeling of DOTA-PEG-A9 was carried out by addition of 68GaCl3 (185 MBq) eluted from 68Ge/68Ga generator (ITG, Germany) to the peptide (50 μg) dissolved in sodium acetate buffer (100 μL, 1.5 M, pH 4) followed by incubation (80°C, 10 min). Radiolabeling yield and stability of 68Ga-DOTA-PEG-A9 was determined by RP-HPLC. Results: DOTA-PEG-A9 could be synthesized in >99% purity. Radiolabeling yield of 68Ga-DOTA-PEG-A9 was >98% as determined by RP-HPLC. The radiotracer was observed to be hydrophilic (log P = -3.29±0.1). Stability studies were carried out after 2 h of preparation of radiotracer and no change in retention time or radio-chromatogram pattern indicated stability of 68Ga-DOTA-PEG4-A9. Conclusion: Peptide-based HER2 targeting molecular probe, 68Ga-DOTA-PEG-A9 has been synthesized in high yields and exhibited adequate in vitro stability. In vitro and in vivo evaluation studies for confirming its receptor specificity are in progress.


   PP24: 177Lu-labeled Polyamidoamine dendrimer conjugated with cRGDfK and doxorubicin Top


Kusum Vats, Amit Kumar Sharma, Haladhar Dev Sarma, Drishty Satpati, Ashutosh Dash

BARC, Mumbai, Maharashtra, India.

Aim: Polyamidoamine (PAMAM) dendrimers are hyperbranched, small size, spherical nanoplatforms with abundant surface functional groups. Depending on the size and molecular weight dendrimers are classified into different generations (G0-G5). Surface functionalities of PAMAM can be easily modified by conjugation with peptides, recognizing receptors associated with cancer cells. In the present work cRGDfK peptide and doxorubicin have been conjugated with G4.COOH dendrimer and radiolabeled with 177Lu and biodistribution studies have been performed in tumor bearing mice. Materials and Methods: The carboxyl functionalities of G4 PAMAM dendrimer (10 mg, 0.48 μmol) were activated by vigorous stirring with 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) (4 mg, 0.02 mmol) and N-hydoxysuccinimide (NHS) (2 mg, 0.02 mmol) in dimethylformamide (DMF)/ water (4:1 v/v, 2 mL) at room temperature for 14 h. The activated G4 PAMAM was allowed to react simultaneously with cRGDfK (3 mg, 5 μmol), p-NH2-Bz-DOTA (3.5 mg, 5 μmol) and doxorubicin (2 mg, 3 μmol) for 24 h at room temperature. The final conjugate, PAM-RGD-DOTA-DOX was purified by ultrafiltration (Ultrafilters, MWCO 3000, Millipore) and characterized by FT-IR and UV absorption spectroscopy. PAM-RGD-DOTA-DOX was radiolabeled by addition of 177LuCl3 (185 MBq) in presence of sodium acetate buffer (0.1 M, pH 5). The reaction mixture was incubated at 90°C for 20 min, purified by PD-10 column and analyzed by radio-TLC. Biodistribution studies were carried out in C57BL/6 mice bearing melanoma tumor. Results: 177Lu-PAM-RGD-DOTA-DOX was obtained in ~70% radiochemical yield and >98% radiochemical purity. In biodistribution study, kidney uptake of 177Lu-PAM-RGD-DOTA-DOX was observed to be 3.5±0.2% ID/g at 3 h p.i. whereas all other organs including tumor exhibited uptake of ≤1% ID/g. Rapid urinary excretion and fast clearance of radioactivity from the blood pool suggests highly hydrophilic nature of the nanosystem in present form. Conclusion: The G4 PAMAM dendrimer could be suceessfully conjugated to peptide cRGDfK, bifunctional chelator DOTA and drug doxorubicin. The biodistribution pattern indicates the need to introduce a pharmacokinetic modifier such as polyethylene glycol (PEG) so as to increase the blood circulation and thus improve the pharmacokinetics.


   PP25: Automated 90Y-DOTATATE production: Using indigenously developed automated radio-synthesizer Top


N. Yuva Raj, A. Mitra, C. Rajesh, S. Banerjee

RMC, Mumbai, Maharashtra, India.

Aim: 90Y-DOTATATE is a promising therapeutic radiopharmaceutical for treatment of large sized neuroendocrine tumors with lesions size ≥5 cm. The increasing clinical demand of 90Y-DOTATATE prompted the need for automation of production process to fulfil regulatory and radioprotection issue for hospital-based preparation set up. Herein we report the development of a fully automated radiochemical synthesis process for 90Y-DOTATATE production compatible with GMP regulation. Materials and Methods: Control-Unit: The in-house developed automated synthesis module constitutes an embedded system-based hardware interface as control system and PC based Graphic User Interface (GUI). The automated synthesis module is based on 32-bit microcontroller ESP32 with wireless connectivity and relay driver interfaces to operate the relays for actuating solenoid valves and linear actuator-based syringes for dispensing reagents and facilitating volume transfers to the reaction vial. The GUI sets the timing sequence of solenoid-valves, peristaltic-pumps and PID temperature-controlled lead shielded heater, while acquiring signal temperature sensor and PIN diode-based radioactivity detectors to validate the process during radiochemical synthesis. Radiochemical-Synthesis Unit: The microcontroller initiates the automatic transfer of 90Y-Acetate from stock vial to reactor via peristaltic-pump with commands from PC and facilitates the transfer of 0.2M CH3COONH4 buffer and 100 μL DOTATATE from different reservoir to reactor in sequential manner. The module facilitates the automated transfer of gentisic acid to reaction-vessel, saline for dilution and finally transfer of product to sterile vial through 0.22 μm membrane filter. The automated synthesis module has also options for automated purification of the product through SPE-column if radiochemical purity (RCP) falls <90%. Results: Using indigenous automated synthesizer, formulation of 50-55 mCi of 90Y-DOTATATE has been carried out successfully (n=7). The 90Y-DOTATATE prepared using indigenously developed automated synthesizer found to be clear, pale-yellow color, pH (4.5-5.5), RAC (8-12 mCi/mL), RCP of all the produced batches was >98%, while RLY was 80-85%. The final product complies tests for apyrogenicity and sterility. The product was stable upto 72 h on storage at -20oC in presence of gentisic acid (stabilizer) against radiolytic dissociation. Conclusions: An automated process for 90Y-DOTATATE production using in-house developed automated synthesis module was successfully developed for reliable and reproducible routine production. The RLY of product are reproducible, showing excellent stability with RCP >98%. The software, hardware and radiochemical synthesis method sequences were developed in-house and implemented. Prime advantage derived from the use of this automated module is the significant reduction of the radioactive dose incurred by the personnel involved in the regular production of 90Y-DOTATATE.


   PP26: Synthesis and comparative in-vivo evaluation of 68Ga-labeled DOTA-GA and NODA-GA coupled 2-nitroimidazole as PET tracers for imaging hypoxia Top


Sweety Mittal, Madhava B. Mallia, Haladhar Dev Sarma, Ashutosh Dash

BARC, Mumbai, Maharashtra, India.

Introduction: Hypoxia plays a negative role in the clinical management of cancer. Detection of hypoxic status of cancer is important for selecting patients for hypoxia directed therapy. [18F]Fluoromisonidazole ([18F]FMISO), a PET radiopharmaceutical, is presently being used in the clinics for the detection of hypoxia. The goal of this study is to develop a 68Ga-based hypoxia imaging agent with superior pharmacokinetics than [18F]FMISO and which is convenient to formulate in clinical settings. Materials and Methods: 2-nitroimidazole-propyl amine (2-NIM) was synthesized and conjugated to p-NCS-benzyl-DOTA-GA and p-NCS-benzyl-NODA-GA to get the target compounds [2-NIM-DOTA-GA (1) and 2-NIM-NODA-GA (2)]. The prepared conjugates were purified by semi-preparative HPLC and characterized by appropriate spectroscopic techniques. The radiolabeling was carried out by adding 68GaCl3 (2 mCi, 74 MBq), obtained from ITG 68Ge/68Ga generator to 2-NIM-DOTA-GA (300 μg) / 2-NIM-NODA-GA (250 μg) in presence of NaOAc buffer (300 μL, pH = 4) in boiling water bath for 20 min. Complexation yield and radiochemical purity (RCP) of the radiolabeled conjugates were determined by reversed phase HPLC using C-18 column. Biodistribution studies of the radiolabeled conjugates (1 and 2) were carried out in Swiss mice bearing fibrosarcoma tumor at three different post-administration time points (30 min, 1 h and 2 h). Results: The RCP of both the radiolabeled conjugates were found to be >98 % after purification with C-18 reverse phase Sep-Pak® cartridges. The octanol/water partition coefficient (log Po/w) for 2-NIM-DOTA-GA (-2.42±0.19) and 2-NIM-NODA-GA (-2.62±0.14) indicated hydrophilic character of the radiotracers. The radiolabeled complexes showed good stability in human serum. Biodistribution studies showed good tumor uptake (5.18 ± 0.93) and retention over the period of study with high tumor to muscle ratio (5.88 at 2 h post-administration). Conclusion: The present work describes synthesis of two 68Ga-nitroimidazole complexes for imaging hypoxia. Biodistribution studies in fibrosarcoma tumor bearing Swiss mice indicated the potential of the agent. However, further detailed investigations are needed to find out the actual potential of these agents as PET tracers for imaging hypoxia.


   PP27: Preclinical evaluation of a multi-dose formulation of Lu-177-DOTA-prostate specific membrane antigen-617 for clinical translation in metastatic castration resistant prostate cancer patients Top


Sudeep Kumar Sahu, Arpit Mitra, Avik Chakrabotry, Hemant H. Shimpi, Sangita Lad, Megha Tawate, Sujoy Gaikwad, Sutapa Rakshit, C. Rajesh, Sharmila Banerjee

RMC, Mumbai, Maharashtra, India.

Introduction: 177Lu-DOTA-PSMA-617 has been a promising radiopharmaceutical for targeting Prostate Specific Membrane Antigen. We have optimized radiolabeling parameters for multi-dose formulation (700-750 mCi) of 177Lu-DOTA-PSMA-617 using 177Lu produced by n,g route in Indian research reactor with specific activity (SA) in the range of 15-18 mCi /μg. The quality control procedures have been optimized. In-vitro cell binding in LNCap cell lines and organ-distribution in nude mice bearing LnCap xenografted tumor has been carried out. Treatment carried out with several batches of present formulation in metastatic castration-resistant prostate cancer (MCRPC) patients indicated desired distribution at tumor and its metastatic site. Materials and Methods: Clinical grade 177LuCl3 produced using enriched 176Lu target. Production of 177Lu-DOTA-PSMA-617 optimized using 177LuCl3 buffered with 0.1M CH3COONH4, 40 mg gentisic acid and 690 μg PSMA-617 having metal : ligand ratio of 1:2.5. Reaction mixture incubated at 95oC for 45 minutes at pH 4.5.177Lu-DOTA-PSMA-617 diluted with saline and filtered. RCP assessed by TLC (SG-60Ao, acetonitrile/water-1/1) and HPLC (H2O/CH3CN, RP18-column). Endotoxin-limit quantified by LAL-test, sterility by direct-inoculation. In-vitro stability evaluated by TLC and HPLC at 24 h, 48 h, 72 h post-radiolabeling on storage at -20oC. In-vitro cell-binding was performed by incubating LNCaP cells in 1 mL of internalization buffer containing radioligand (0.5 pM) at 15, 30, 45, 60 min followed by washing with PBS. Biodistribution carried out in xenografted LNCaP-tumor bearing nude mice injecting 177Lu-DOTA-PSMA-617 (100 μCi) at 6 h, 24 h, 48 h, 72 h time-points. Quantification of radioactivity performed in γ-spectrometer. Patient evaluation studies were performed in 157 patients suffering from MCRPC using 177Lu-DOTA-PSMA-617 formulation prepared in 61 different batches. The clinical single patient dose of 177Lu-DOTA-PSMA-617 is 120 – 150 mCi. Results: Study demonstrates the suitability of low SA 177Lu in preparation of multi-dose formulation of 177Lu-DOTA-PSMA-617 for clinical administration. 177Lu-DOTA-PSMA-617 showed 22% binding in LNCaP cells. In-vivo biodistribution studies demonstrates, radioactivity in blood and other organs decreased after 24 h p.i. High-uptake and long-retention of radioactivity found in tumor (8.02% ID/gm) which corroborates with scintigraphy studies. The radiotracer distribution indicates excellent targeting of ready-to-use 177Lu-DOTA-PSMA-617 at MCRPC sites of the patients. Conclusion: A protocol for multi-dose formulation of 177Lu-DOTA-PSMA-617 for therapy of MCRPC was developed using low SA 177Lu. The product retained its RCP >98% upto 72 h post-radiolabeling when stored at -20oC with high RAC (45 mCi/mL). The radiotracers expected distribution in patients with castration resistant prostate tumors and its metastases, has also been proved to be clinically efficacious with respect to the expected therapeutic outcome.


   PP28: Radiosynthesis and in vitro evaluation of 68Ga-NODAGA-RGD as a radiotracer for imaging integrin αvβ3 receptor overexpression Top


Ashok R. Chandak, Sutapa Rakshit, M. K. Ray, Sharmila Banerjee

RMC, Mumbai, Maharashtra, India.

Aim and Introduction: The present work deals with the radiolabeling and in-vitro evaluation of NODAGA-RGD(f)K and NODAGA-[RGD(y)K]2 with 68Ga3+ eluted without fractionation from a commercial 68Ge/68Ga generator. Targeting tumor cells or tumor vasculature by peptides is a promising strategy for delivering cytotoxic drugs for cancer therapy. The Arg-Gly-Asp (RGD) dimeric sequence has been known to bind effectively with the αvβ3 integrin receptors. Among the various radionuclides, 68Ga is the most widely studied for varying peptide imaging because of its excellent nuclear physical properties, easy-to-label chemical properties, and cost-effectiveness owing to the availability of 68Ge/68Ga generator. This study deals with radiosynthesis and evaluation of monomer and dimer derivativesof RGD labeled with 68Ga. Materials and Methods: The NODAGA-RGD(f)K (piCHEM) and NODAGA-[RGD(y)K]2 (ABX) were used (10 μg, 20 μg, 30 μg and 40 μg) for labeling with 68Ga obtained from 68Ge/68Ga (50 mCi/1850 MBq, itG) generator. The synthesis was carried out aseptically in Eckert & Ziegler automated module. Varying molarity of acetate buffer (0.5–2.0 M) pH 4.0 and 5 M acidified NaCl preclean solution were used for the synthesis. The time and temperature of reaction has been optimized. The generator was eluted with 4.0 ml of 0.05 N HCl and 68Ga was purified using Strata-SCX (Phenomenex) cation exchanger. The final producthas also been purified using tC18 column (Waters, USA). The products were evaluated for physicochemical characteristics. The stability of the labeled product were also evaluated up to 4 h in human serum. Results: Full scale automated synthesis of 68Ga-RGD was done from 68Ge/68Ga generator (50 mCi). The optimum radiolabeling yield was obtained using acetate buffer (1.0 M) pH 4.0, at 95 oC heating for 6 mins. There was less than 3 % (± 1) of the activity was found in the waste vial and less than 1% activity was found trapped in tC18 column after collection of the product. Production yield was proportional to concentration of the ligand up to 30 μg. The RCP was found to be 98 % (± 1.5 %) using ITLC-SG (0.1 M CB, product Rf = 0.0-0.1 and Whatman-3 PC (50 % ACN product Rf = 0.5-0.6) and was found stable up to 4 h on incubation in human serum. Conclusion: The physicochemical and other quality control data was found to be in compliance with the GMP/GRPP guidelines for both the products prepared with 68Ga. Preclinical studies in animal models are underway.


   PP29: Radiosynthesis and evaluation of 177Lu-NODAGA-RGD monomer and dimer Top


Ashok R. Chandak, Sutapa Rakshit, Avik Chakraborty, M. K. Ray, Sharmila Banerjee

RMC, Mumbai, Maharashtra, India.

Aim and Introduction: The present work is on the radiolabeling and in-vitro evaluation of NODAGA-RGD(f)K and NODAGA-[RGD(y)K]2 with 177Lu3+ for targeting integrin αvβ3 receptors overexpression in angiogenetic tumor. Integrins belong to a family of αvβ3 heterodimeric transmembrane glycoproteins involved in cell-cell and cell-matrix interactions. Theintegrin αvβ3 is known to play an important rolein tumour-induced angiogenesis, tumour proliferation, survival and metastasis. The Arg-Gly-Asp (RGD) sequence has been known to bind with the αvβ3 integrin that is expressed on the surface of angiogenic blood vessels or tumour cells. Thus, monomer and dimer derivatives of RGD linked with NODAGA chelator and radiolabeled with 177Lu3+ have been evaluated as targeting agent for angiogenetic tumors. Materials and Methods: The NODAGA-RGD(f)K (piCHEM) and NODAGA-[RGD(y)K]2 (ABX) were used at 1:4, 1:6, 1:8 μmol ratio (177Lu:peptide) for labeling with 177Lu obtained from BRIT (Specific activity (20 ± 5) mCi/μg). The synthesis was carried out aseptically in a laminar flow bench (manually) using 700 MBq of 177Lu activity. Optimization of radiolabeling was carried out at varying molarity of acetate buffer (0.2–1.0 M), with and without gentisic acid (10 mg/ml & 20 mg/ml) at pH (5.0, 5.5 and 6.0) conditions. The reaction time and temperature also has been optimized. The product was purified by passing through preactivated C18 column. Physicochemical QC studies which included pH, colour and RCP were carried out. Cell line uptake studies and the serum stability was determined up to 24 h at room temperature. Results: Synthesis of 177Lu3+-RGD is done with NODAGA-RGD monomer and dimer using 0.4 M molar acetate buffer at pH 5.5 with 10 mg/ml gentisic acid and without gentisic acid. The production yield was found to be maximum at 1:6 μmol ratio of 177Lu:peptide biomolecule at temperature 95 oC (±3oC) for 35 min. RCP was found 99 % (± 3%) using ITLC-SG (0.1 M CB, product Rf = 0.0-0.1), Whatman-3 PC (50% ACN product Rf = 0.5-0.7) and (50% ethanol product Rf = 0.8-1.0). The product was found stable at room temperature for 24 hrs. There was no coloration found in the product in absence of gentisic acid up to 24 h which is produced in presence of gentisic acid. The product has shown increasing uptake up to 4 hours in selected cell line and found reducing afterward. Conclusion: The quality control data was found to be compliant with specifications for both the products. Laminar flow bench synthesis allows radiopharmaceutical production which is in compliance with the GMP/GRPP guidelines. Preclinical evaluation in suitable animal models are underway.


   PP30: On the radiolabeling of rituximab, trastuzumab and pertuzumab with low specific activity (Lu-177) chloride Top


Sudeep Kumar Sahu, Arpit Mitra, Megha Tawate, Sangita Lad, Avik Chakraborty, Sreeja Menon, C. Rajesh, Sharmila Banerjee

RMC, Mumbai, Maharashtra, India.

Aim: Radioimmunotherapy (RIT) using 177Lu-labeled monoclonal antibodies is increasingly gaining prominence in therapeutic nuclear medicine practices. Towards the use of these agents, the major challenges involved are preparation of the clinical dose and optimization of radiolabeling parameters of differently conjugated 177Lu- labeled monoclonal antibodies (MoAbs) viz. 177Lu-DOTA-Rituximab, 177Lu-DOTA-Trastuzumab and 177Lu-DOTA-Pertuzumab. Efficient radiolabeling of these MoAbs with varied molecular weight (143–148 KDa) depends on optimum pre-concentration, incubation-temperature, time and pH of conjugation and suitable purification of immunoconjugates. The present study merits the development of a single protocol which has been optimized for conjugation of rituximab, trastuzumab and pertuzumab with p-NCS-benzyl-DOTA and radiolabeling of these immunoconjugates using low specific activity (LSA) 177LuCl3. Materials and Methods: Commercial rituximab, trastuzumab, pertuzumab (5.0 mg/500 μL) preconcentrated to 80–100 μL using 30kDa MW cut-off ultra-centrifugal filtration-device at 3000 g for 17 minutes. Coupling of rituximab, trastuzumab, pertuzumab with p-NCS-benzyl-DOTA carried out at 1:10 molar ratio under incubation at 24oC (2 h), followed by 4oC (18 h) at pH~8.0. Reaction-mixtures purified using pre-conditioned PD-10 columns. All the three immunoconjugates eluted from PD-10 using 0.2M CH3COONa-buffer (pH~5.5) and concentrations estimated by Bradford's-assay. The number of DOTA molecules per antibody determined by spectrophotometric-method using Pb(II)-Arsenazo(III) complex. Prior to radiolabeling, pH of 177LuCl3 (250-300 mCi, SA: 15-20 mCi/μg) adjusted to 6.5, using 0.2M CH3COONa solution. 177Lu-acetate incubated with all the three purified immunoconjugates at 37oC for 90 minutes. Radiolabeled reaction-mixture purified using pre-conditioned PD-10 column. In-vitro stability of radioconjugates ascertained by adding ascorbic acid (60 mg). The RCP evaluated using TLC and HPLC both. Results: Using 300 mCi of LSA 177LuCl3 (15 mCi/μg), all the three radioconjugates (80-85 mCi) could be prepared. All the three radioconjugates were clear and colorless, pH (5.5-6.0) and RAC (8-10 mCi/mL). The RCP of all the three radioconjugates estimated by TLC was >98% (Rf: 0.0-0.1), while RCP derived by HPLC was >98% (Rt: 11-13 minutes). The RLY of all the three radioconjugates were between 32-35%. The EL was <6 EU/mL and product was sterile with in-vitro stability upto 96 h (storage at -20oC) with stabilizer. In all the three immunoconjugates, number of DOTA attached per antibody were ~3 and MoAbs concentration were ~2.8 mg/mL. Conclusion: A single, protocol could be successfully optimized for coupling of rituximab, trastuzumab, pertuzumab with p-NCS-benzyl-DOTA. The subsequent radiolabeling with 15-20 mCi/μg of 177LuCl3 yielded patient doses of the radioconjugates i.e 177Lu-DOTA-Rituximab, 177Lu-DOTA-Trastuzumab and 177Lu-DOTA-Pertuzumab. Further studies towards clinical translation of all the three radiopharmaceuticals in patient are underway.


   PP31: Pre-clinical evaluation of no carrier added [Cu-64]Chloride from APSARA-U in tumor xenografts by positron emission tomography/computed tomography Imaging Top


Sutapa Rakshit, Avik Chakraborty, Arpit Mitra, Sangita Lad, Rubel Chakravarty, Sudipta Chakraborty, Ashutosh Dash, Sharmila Banerjee

RMC, Mumbai, Maharashtra, India.

Aim: In recent time, 64CuCl2 is gaining prominence as a diagnostic PET radiotracer for applications in a wide variety of cancer, owing to its favorable nuclear characteristics {T1/2: 12.7 h, EC (43.8%), β+Emax: 651 keV (17.7%), β-Emax: 578 keV (38.5%)}. The applicability of 64CuCl2 as a PET radiopharmaceutical stems from the fact that Cu is an essential element which plays an important role in cell proliferation and angiogenesis. 64Cu (II) is reduced to Cu (I) by reductases, followed by influx of copper by copper transporter 1 (hCTR1) in human cells. In the present study, efforts have been made to analyze the efficacy of 64CuCl2 through PET/CT imaging in tumour bearing nude mice and normal rabbits and carrying out internal dosimetry. Materials and Methods: High specific activity no-carrier-added 64Cu was produced by 64Zn (n, p) 64Cu reaction in the APSARA-U reactor and radiochemical processing was carried out at Radiopharmaceuticals Division, BARC. Cell uptake and internalization potential was investigated using AR42J, B16F10 and MCF7 cell lines. PET/CT imaging and biodistribution studies were performed in mice with xenografted tumor generated using all the three cell lines. Carcinoma cell-line were grown in IMDM medium with 10% FBS in 5% CO2 at 37oC. The nude mice were injected with carcinoma cell lines (2 x 106 cells/mice) at the proximal flank region of the mice and tumor was allowed to grow till 1 cm3 for experimentation. The 64CuCl2 (200 μCi/mice) was injected in xenografted mice through tail vein. PET imaging was performed using GEMINI-TF 16-Slice PET/CT instrument with customized CT parameters of 90 V/100 mA with slice thickness of 2 mm and PET parameter of 10 minutes emission window/bed. Degree of receptor mediated uptake of the radiochemical was determined by biodistribution studies and SUVmax obtained from PET imaging study. Results: The PET/CT imaging performed at intervals of 2 h, 4 h, 24 h, 48 h and 72 h post injection using ketamin/xylazine injection for anesthesia, showed incremental accumulation of 64Cu in initial 4 h. Biodistribution analysis corroborated well with the PET analysis, which revealed maximum uptake in the tumour after 4 h post-injection and retention therein till 48 h. For rabbit PET/CT imaging, 1 mCi radionuclide injected through ear vein showed high uptake and long-term retention of radioactivity in liver as 64CuCl2 shows hepatobiliary clearance. Conclusion: Initial studies document the promising potential of NCA 64CuCl2 as a PET radiotracer in the form of a simple radiochemical. Preclinical development of this agent for subsequent clinical translation in patient are underway.


   PP32: Usage of pH as a primary quality control method for a successful Ga68-Dotanoc product Top


Priya Monteiro, Mehjabeen Pathan, Bhakti Shetye, Rutuja Parab, Archi Agrawal, Nilendu Purandare, Sneha Shah, V. Rangarajan

TMH, Mumbai, Maharashtra, India.

Aim: Ga 68 Dotanoc preparation in an IQS Ga68 Fluidic Labeling module by ITG takes 30-45 minutes. The quality control (Q.C.) procedure involves checking the pH of the final product followed by radiochemical purity (R.C.P.), which itself, takes another 10-15 minutes. If a relation can be found between the pH and the R.C.P., then the pH alone can be designated as the primary Q.C. parameter for a successful Ga68 Dotanoc product, and patient injections can begin earlier. Materials and Methods: To check the pH, a drop of diluted Ga68 Dotanoc was put on MColorplast pH indicator strip (pH Range 0-6). The colour change was compared to the corresponding standard values on the indicator strip to obtain the pH value instantly. To check the R.C.P., a drop of diluted Ga 68 Dotanoc was spotted using ITLC paper {Merck Millipore TLC silica gel 60 F254 aluminium sheets} as stationary phase and 0.1 M Na citrate as the mobile phase, and counted in a gamma ray spectrometer. The R.C.P. was calculated as follows : (Counts at the point of spotting/ Total counts) * 100. Results: The pH of Ga68 Dotanoc was found to be 5.5 that corresponded with an average R.C.P. of 97.75 +- 2.18%, irrespective of the product activity. Conclusion: Thus pH can be used as a primary Q.C. parameter for determining a successful Ga 68 Dotanoc product, on the basis of which patient injections can take place earlier.


   PP33: Is there any correlation between tumour volume and other radiomic features Top


Ashish Kumar Jha, V. Jaiswar, S. Mithun, U. B. Sherkhane, L. Wee, G. Misra, Z. Shi, V. Rangarajan, A. Dekker

TMH, Mumbai, Maharashtra, India.

Introduction: Radiologists presently interpret CT, MRI, PET by unaided eye to diagnose various oncological conditions. Visual interpretation alone of clinical radiological images does not always exploit all of the implicit information encoded into the enhancement, morphology or texture of the tumour. Numerous studies demonstrate the potential of image-derived “markers” to characterize heterogeneous tumour phenotypes and hence predict/prognose for clinical outcome. Radiomics is quantitative image analysis where a computer algorithm extracts many mathematical features from an image of an entire solid tumour. Repeatability and reproducibility of features,[1] risk of over-fitting and potential confounding by tumour volume are serious concerns that affect generalizability of radiomic-based prediction models. Aim: To determine features that are at high risk of confounding by tumour volume. These features should be excluded from the set of candidate features for predicting outcomes pertaining to cancer survival. Materials and Methods: 30 NSCLC (Non-Small Cell Lung carcinoma) patients' CT scan data was used for radiomic feature extraction using open source extraction software Pyradiomics (version 2.1.2) without the use of any digital pre-processing filter. In total 1093 features were extracted from the primary lung gross tumour volume. A Spearman correlation coefficient was computed in R programming to find all other 1092 features that show rank correlation with volume i.e. “MeshVolume” feature. Results: 104, 159 and 232 features had strong dependence on tumour volume with correlation coefficient thresholds of 0.9, 0.8 and 0.7, respectively. Maximum correlation (> 0.99) was found for intensity histogram-based feature Energy. Conclusion: Our study suggests that up to a quarter of non-filter radiomics features have an increased risk of confounding by tumour volume. This risk needs to be taken into account when selecting candidate features to use in a radiomics prediction model.


   PP34: Eco-friendly semi-automated sterility testing method for injectable radiopharmaceuticals – Feasibility study and validation Top


Chanda Arjun, Aaditya Shah1, Barakha Karkhanis, Chetan Kothalkar1, Aruna Korde2, A.C. Dey1, D. Padmanabhan1, Sharmila Banerjee3

Quality Control, Radiopharmaceuticals Programme, Board of Radiation and Isotope Technology, 1Technology Development Group, Radiopharmaceuticals Programme, Board of Radiation and Isotope Technology, Navi Mumbai, 3Radiation Medicine Centre, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India, 2Division of Physical and Chemical Sciences, International Atomic Energy Agency, Vienna, Austria.

Background: Various diagnostic and therapeutic radiopharmaceuticals are regularly supplied for clinical use across India by BRIT. BRIT QA/QC monographs and Indian Pharmacopeia approve parametric release of short lived injectable radiopharmaceuticals as it is not feasible to complete the Sterility Test (ST) before the product is released. However, as a good manufacturing practice, it is mandatory that the test be commenced at the earliest. Conventional methodology for ST involves manual transfer of test samples - minimum four vials per batch -into sterile growth media under aseptic conditions. This method is time-consuming, requires skilled persons and results in considerable radiation exposure to analyst in routine testing facilities. We describe here a simple vacuum-based manifold system which was designed in house, validated and tested in routine use to circumvent these problems. In order to make this test economical and environmentally friendly, spent consumables discarded as waste from the 68Ga-radiopharmaceuticals production facility were reused by sterilising them by means of gamma radiation in the Radiation Processing Plant (RPP), BRIT. Methodology: The vacuum-based manifold system consisted of four silicone tubings (Masterflex) connected to a vacuum pump and attached to sterile needles. These needles were introduced into Fluid Thioglycollate Medium (FTM) and Soyabean Casein Digest Medium (SCD) bottles (HiMedia Laboratories). Sterile assemblies containing a spinal needle (18G) connected to a sterile needle (23G) via silicone tubing were used. These assemblies were obtained from the waste generated from the 68Ge-68Ga generator after production of 68Ga radiopharmaceuticals, allowed to decay until certified to be inactive and then cleaned by rinsing with sterile Water for Injection. These were sterilised by gamma radiation at RPP, BRIT by using a radiation dose of 25 kGy. This dose is suitable for sterilization purposes, chosen based on radiation resistance of bacterial spores of the radio-resistant micro-organsim, Bacillus pumilus. The 25 kGy dose is higher than necessary for achieving sterility and reaching a Sterility Assurance Level of 10-6 (SAL, one micro-organism surviving after treatment in a sample of 106 micro-organisms, or one non-sterile item after sterilization of a batch of 106). The spinal needles were introduced into the sample vials such that their tip touched the base of the vials. Individual vacuum control for each of the four sets was done using solenoid valves placed between the media bottles and the vacuum trap. Switching on the vacuum and respective solenoid valve ensured withdrawal of the entire sample volume through the spinal needle and tubing into the media vial. Test samples were housed in slotted lead stand of appropriate thickness. The whole assembly was set up inside a Biosafety Cabinet (Class III). The inoculated media were incubated at 30-35oC and 20-25oC respectively for 14 days and examined for microbial growth by visual examination. Sterile saline was used to inoculate the media in the same manner and used as controls. The radiopharmaceuticals tested by this method included: 153Sm-EDTMP, 131I-mIBG and Na99mTcO4 eluates from 90Mo-99mTc generators (04 batches each, RAC ~20 mCi/mL (740 MBq/mL) per vial). Results: All the injectable radiopharmaceutical products tested passed the ST as indicated by absence of microbial growth on completion of the 14 days incubation period. Conclusion: The adaptation of the ST method using a vacuum manifold, besides being safe and time saving, provides a reliable quality control testing option for radiopharmaceuticals and decreases personal errors. Recycling the waste from the 68Ge-68Ga generator for use as consumables for this test will result in cost-saving as a result of the potential for in house re-use of these materials as well as considerable reduction in the quantum of environmental waste generated. This method can result in a significant reduction in the radiation dose received by the analyst and provides a feasible alternative to the conventional method.


   PP35: DAE medical cyclone-30, Kolkata: Production of fluorine-18 fluorodeoxyglucose using IBA-synthera module Top


Sujata Saha Das, Luna Barua, Shayantani Ash, Asit Kumar Pal, D. G. Mahesh, Arup Kumar Hudait, Umesh Kumar, Madhusmita, Sumita Chattopadhyay, Md. Nayer Alam, Sankha Chattopadhyay

Regional Centre, BRIT, Kolkata, West Bengal, India.

Aim: Cyclotrons are used to produce radioisotopes for diagnostic and therapeutic use for cancer care. IBA Cyclone-30, 30 MeV, 350A proton cyclotron is the biggest cyclotron in India for the production of radioisotopes /radio pharmaceuticals for medical application became operational in September, 2018. SPECT (Single-Photon Emission Computed Tomography) Isotopes (67Ga, 111In, 123I, 201Tl) (India is still importing these Isotopes and presently this being a costly treatment does not reach to many people in the society); PET (Positron Emission Tomography) isotopes (F-18, Ge-68/Ga-68 generator for in situ production of Ga-68,Cu-64,Zr-89, I-124 etc) and therapeutic isotope, Pd-103 will be produced in the Cyclone-30. Here, we report the production of 18F-FDG. Materials and Methods: The production of 18F was achieved by irradiating H218O using IBA niobium target assembly (1.8 ml in 2.4 ml Nb target cavity) with 18 MeV, 25-30 μA average proton beam current (total beam current 25Ah) and subsequent production of 18F-FDG has been carried out in hot cells (Comecer, Italy) using IFP (integrated fluid processor) cartridge in IBA synthera module. The production of 18F-FDG has been evaluated for 6 batches including the complete physico-chemical as well as biological quality control tests. Results: The production yield of 18F-FDG varied from 65-70 % (without decay corrected). The radiochemical purity of the 18F-FDG has been found to be 99.9% by using TLC method. The radionuclidic purity was greater than 99.99% (determined by HPGe). The presence of Kryptofix in the final product was found to be less than 0.22 ppm. The Bacterial endotoxin in 18F-FDG was found <10 EU/ml determined by PTS method. Each batches were evaluated for sterility test and each batch pass the sterility test. Conclusion: The production of 18F-FDG in cyclone-30 has been achieved successfully. Regular production and supply to hospitals will commence after getting clearance of Radiopharmaceuticals Committee (RPC), DAE and AREB. The production of other isotopes will also be initiated soon.


   PP36: In-house radiolabelling and quality control of 99mTc-ceftriaxone and 99mTc-ciprofloxacin Top


Satyam Kumar, Geetanjali Arora, Nishikant A. Damle, Chandrasekhar Bal, Madhavi Tripathi, Bisakh Bhattacharya, Piyush Ranjan, Meivel Angamuthu, Sneha Prakash, Naresh Kumar

AIIMS, New Delhi, India.

Aim: We hypothesize that specific antibiotics if radiolabeled successfully with a diagnostic radionuclide, could have a theranostic value. Very few studies are available with the in vivo use of 99m Tc- Ceftriaxone in infection imaging. In the present study, ciprofloxacin and ceftriaxone were radiolabeled with 99mTc followed by in vitro quality control, as an initial step before using these tracers in vivo. Materials and Methods: HPLC grade ciprofloxacin and ceftriaxone was procured from Merck (KGaA, Darmstadt, Germany). All other chemicals used were analytical grade. Labelling was performed by reduction method. Briefly, 100 ug stannous chloride was added to 2 mg ciprofloxacin followed by the addition of 15-30 mCi 99mTc-pertechnetate. The mixture was then incubated at room temperature for 30 min. Labelling efficiency (LE) was checked by paper chromatography using Whatman paper 1 as stationary phase and methyl-ethyl ketone as mobile phase. Similarly, 50 ug stannous chloride was added to 30 mg ceftriaxone followed by the addition of 15-20 mCi 99mTc-pertechnetate. The mixture was then incubated at room temperature for 30 min. LE was checked by paper chromatography using Whatman paper 1 as stationary phase and acetone as mobile phase. Results: Total number of syntheses conducted was 10 each for ciprofloxacin and ceftriaxone. Mean LE for ciprofloxacin was 97 ± 1.49% and for ceftriaxone was 96.95 ± 2.82%. Since diagnostic radiopharmaceuticals need to have a labelling efficiency of > 90%, we could consistently radiolabel both the antibiotics with LE>95% in our laboratory set up. Conclusion: Both ciprofloxacin and ceftriaxone could be successfully radiolabeled with 99mTechnetium in-house.


   PP37: Synthesis of super paramagnetic iron oxide nanoparticles containing manganese ferrite core for radioisotope based biomedical applications Top


Shripriya Purohit, Archana Ghodke, Vijay Kadwad, K. Bhaskar Shenoy1

Board of Radiation and Isotope Technology, Navi Mumbai, Maharashtra, 1Department of Applied Zoology, Mangalore University, Mangalore, Karnataka, India.

Aim: Water dispersible super paramagnetic iron oxide nanoparticles (SPIONs) containing manganese ferrite core with high magnetization value and particle size below 100 nm were synthesized for use in drug delivery system and tested for ability to conjugate to an antibody and for labelling with radioisotopes. Materials and Methods: Manganese substituted mixed crystal ferrite particles [Mn0.1Fe0.9Fe2O4] were prepared by co-precipitation technique involving precipitation of Fe++ and Fe+++ ions along with Mn++ ions by ammonia solution under controlled experimental conditions. Oleic acid was used as a surfactant to stabilize SPIONs with strong chemical bond between the carboxylic acid and the amorphous magnetic core as well as to achieve biocompatibility. To demonstrate ability of SPIONs for surface modification and for potential use in biomedical applications: (1) Labelling of SPIONs was carried out with 99mTc using direct labelling method (2) 125I radioiodinated antibody was conjugated to SPIONs using EDC conjugation method (3) SPIONs with primary layer of oleic acid were coated with secondary layer of non-toxic PEG 6000. Results and Discussion: Monodispersed SPIONs containing manganese ferrite core coated with primary layer of oleic acid with size of 51 nm were prepared. SEM analysis shows that the SPIONs have uniform spherical shape, FTIR data revealed that oleic acid molecules were adsorbed on magnetic nanoparticles by chemisorption. Synthesized SPIONs exhibited superparamagnetic behavior as evaluated using vibrating sample magnetometer (VSM) with saturation magnetization of 16emu/g. Generator eluate (Na99mTcO4) is reduced with stannous chloride dihydrate which reduces 99mTc to facilitate the formation of radiometal complexes with random groups (hydroxyl and carboxylic) present on the surface of the SPIONs. The 99mTc labeling efficiency as determined using ITLC was found to be above 98%. A representative, 125I labelled anti-T3 antibody (specific activity of 16μCi/μg) was linked covalently to carboxylic groups present on primary oleic acid layer of SPIONs using EDC. PEG functionalization of SPIONs demonstrated versatility and suitability for various biomedical applications. Conclusions: Synthesized SPIONs containing manganese ferrite core due to their intrinsic magnetic, hyperthermic and MRI properties, has the potential to be used in various biomedical applications including SPECT, SPECT/MRI dual-modal imaging and for theranostic applications.


   Oral Presentation: AI and Instrumentation Top



   OP1: Predicting good count image from low count image using machine learning algorithm Top


Anil Pandey, Prateek Kaushik, Shreya Datta Gupta, P. D. Sharma1, Chetan Patel, C. S. Bal, Rakesh Kumar

Department of Nuclear Medicine, AIIMS, 1Department of Computer Science, SGTB Khalsa College, Delhi University, New Delhi, India.

Background: The aim of the study was to predict a good count image from acquired low count image using machine learning algorithm. Materials and Methods: 7-11 MBq 99m-Tc MDP per kg body weight was administered intravenously. After a waiting period of 3-4 hours, the whole body bone scan images were acquired with anterior and posterior view. One hundred whole body 99mTc-MDP bone scan studies were acquired at low speed (3.34 mm/seconds to 8.34 mm/seconds, depending on the counts) and high speed (double of the low speed) without disturbing the patient position using dual head SPECT gamma camera (Symbia E, Siemens Medical Solutions USA, Inc.) equipped with low energy high resolution (LEHR) collimator. Before the administration of Tc-99m MDP, patients were instructed to drink at least one to two litres of water and void their bladder frequently in order to reduce radiation dose. The images acquired at low and high speed were labelled as good count and low count images respectively. The 34 studies (2x 34 = 68 images) were used for training the Multivariate Adaptive Regression Splines (MARS) model and the trained model was tested on 66 studies (2x66 = 132 images). The accuracy of the model was evaluated using the three metrics namely mean absolute error (MAE), mean square error (MSE) and Root mean square error (RMSE). The predicted good count images were also visually compared with acquired good count images by two nuclear medicine physicians. They were asked to provide their preference for one image and were blinded about acquired image and the predicted image. They were also asked to comment regarding whether both images contain the same clinical information or is there any loss of information in either series of images. Their preferences were analyzed. Results: The summary statistics of MAE, MSE, and RMSE is given in [Table 1]. The 2 x 2 table of physician preference is given in [Table 2]. Conclusion: A good count image can be predicted with reasonable accuracy from a low count image using machine learning algorithm without loss of relevant clinical information as demonstrated with 99mTc-MDP whole body scans in the present study.
Table 1: Summary statistics of MAE, MSE, and RMSE

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Table 2: Physician preference

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   OP2: Dose optimization in whole-body 18F-fluorodeoxyglucose positron emission tomography based on NECR measurement and image quality assessment Top


Manpreet Kaur, Nivedita Rana

Department of Nuclear Medicine, PET Centre, PGIMER, Chandigarh, India.

Aim: To quantify NECR and visual Image Quality (IQ) scores in whole-body 18F-FDG PET/CT studies and to compare NECR and IQ in patient injected with different amount of activity based on body-weight. Materials and Methods: A total of 91 patients (30 male, 61 female) who were referred for whole-body 18F-FDG PET/CT from January to March 2019 were included in this prospective study. Depending upon administered activity, patients were categorized into three groups: 100 μCi/kg body-weight (Group1, n=30), 150 μCi/kg body-weight (Group2, n=32) and 200 μCi/kg body-weight (Group3, n=29). For all 91 acquisitions, time elapsed between the injected activity and acquisition was in range of 50 to 70 minutes. All the PET/CT studies were done using 3D-TOF Discovery MI DR PET/CT scanner for 1 minute/bed-position. Trues rate, total prompts and randoms rate for each bed position were noted for calculation of NECR in order to analyze objective IQ. Two 5-point scores were defined to evaluate IQ i.e. local score (for single bed-position) and global score (for whole-body). For subjective assessment, visual analysis of PET images were done by two readers based on prevalence of noise, contrast between different tissues and organs and lesion detectability. The mean values of NECRglobal and IQ global score were compared in all three groups using independent t-test. Also, Karl's Pearson correlation-coefficient was calculated to assess the overall relation of NECRglobal value with IQglobal score as well as with BMI. Results: Mean values of IQglobal for Group1, Group2 and Group3 were 3.11±0.36, 3.76±0.42 and 4.12±0.4 respectively similarly for NECRglobal, mean values were found to be 79.9±8.14, 103.7±11.2 and 120±14.5 for respective groups. Independent t-test showed that mean value of IQglobal scores as well as NECRglobal for the each pair of group were significantly different with p<0.05, overall NECRglobal value was found to be moderately correlated with IQglobal score having correlation-coefficient value, r=0.63 (p<0.05) and was found to be moderately- negatively correlated with BMI (r=-0.576, p<0.05). Conclusion: Quantitative image analysis using NECR values and qualitative image analysis were significantly different as well as positively correlated for each group in whole-body 18F-FDG PET studies. NECR values and IQ scores were higher in patients of high-activity group in comparison to patients of low-activity group. Even in low-activity group, all studies IQ score were acceptable to good. So it can be concluded that even with 100 μCi/kg body weight of activity, diagnostic image quality can be achieved.


   OP3: Standardization of skeletal SUV with Tc-99m methylene diphosphonate obtained by quantitative single-photon emission computed tomography/computed tomography Top


Amit Nautiyal, Viraj Sawant1,2, Ashish K. Jha1,2, Sneha C. Nair1,2, Digvijay Borade1,2, Jay Prakash1,2, V. Rangarajan1,2

1Department of Nuclear Medicine, Tata Memorial Hospital, 2Homi Bhabha National Institute, Mumbai, Maharashtra, India.

Objective: The use of standardized uptake value (SUV) as quantitative imaging biomarker requires standardization in normal bone uptake values for different parts of skeletal system. The primary aim of this study is standardization of Tc-99m methylene diphosphonate (MDP) based SUV in different parts of skeletal system using quantitative single-photon emission tomography/computed tomography (SPECT/CT) obtained for different time points in patients having no bone abnormalities. Materials and Methods: This retrospective study was performed on 28 cancer patients. Patients who underwent whole body planner and SPECT study in our department on NM/CT 670 pro SPECT/CT system, GE healthcare were included in this study. Patients who were having bony abnormalities, higher creatinine, raised serum alkaline phosphatase (ALP), recent CECT or chemotherapy were excluded from the study. Patients were divided randomly in four imaging groups based on 2 hrs, 3 hrs, 4 hrs and 5 hrs imaging time points. The parameters used for the data acquisition were: step and shoot mode, 6 degree angle, 10 second acquisition time, 128 X128 matrix, LEHR collimator with dual energy window for scatter correction. Data analysis was performed using SUV max values obtained by Q matrix toolkit installed on Xeleris 4.0, GE Medical system. SUVmax was calculated based on the patient body weight for different sites ie. skull, thoracic & lumber vertebra, sternum, humerus, pelvis (sacroiliac joint excluded) and femur. SUV max values were also correlated with that of age and BMI. Results: Mean age, mean BMI, mean creatinine, mean ALP were 46.64 ±12.09, 12.48 ±2.90, 0.63 ±0.15, 90.15 ±11.54 respectively. Mean SUVmax value for all skeletal sites and all imaging group are mentioned in the [Table 1]. No statistical significance (p>0.05) were noted in SUV max among the imaging groups. SUVmax of thoracic, lumber, sternum, iliac bones were significantly higher than that of skull bone, humerus and femur (p< 0.01). SUVmax had no significant correlation (r<0.7) with age and BMI for all imaging group. Conclusion: Our study suggests that different skeletal sites show different normal SUVmax values. SUVmax value does not change significantly with changing imaging time. The site specific normal SUVmax range obtained in our study may be utilized to diagnose abnormal tracer uptake in bone SPECT.
Table 1: Mean SUVmax of all skeletal sites

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   Poster Presentation: AI and Instrumentation Top



   PP1: Validation of unlicensed 68Ge/68Ga generator Galli-EoTM for clinical use Top


Chandra Solanki, Luigi Aloj1

Department of Radiology, University of Cambridge, 1Department of Nuclear Medicine, Cambridge University Hospitals, NHS Foundation Trust, Cambridge, England

Aim: In this study we have undertaken the complete validation of the unlicensed Galli-Eo 68Ge/68Ga generator from IRE (this generator has since been licensed for clinical use) with a view to use it for clinical application. The generator has desirable features in that it is bench-top, requires minimal infrastructure, has integrated 0.1M HCl eluent and provides a reproducible and concentrated eluate that can directly be added to radiopharmaceutical kits in a one-step procedure. Materials and Methods: 68GaCl3eluate from the generator was tested as per European Pharmacopoeia monograph 2462 (EP) and United Kingdom Radiopharmacy Guidelines (UKRG). The following tests were performed at least 3 times: Radionuclide identity by gamma spectroscopy and half-life determination. Radionuclide purity by germanium break-through on decayed samples using a calibrated NaI well counter, radiochemical purity (RCP) by thin-layer chromatography using ITLC-SG as stationary phase and ammonium acetate: methanol (1:1) as mobile phase. RCP was analysed using a radiochromatogram scanner fitted with a positron detector head (PS). Trace metal ion content was tested by atomic absorption spectroscopy. Sterility was tested by direct inoculation in double-strength TSA broth. Endotoxin levels were determined by a PTS LAL tester with a pre-determined validation for dilution factors. pH was determined using pH paper, and clarity by viewing under a bright light. The 68GaCl3 was subsequently used to prepare clinical doses of 68Ga-THP-PSMA with a one- step kit based production. Results: In all of the tested samples, the radionuclide identity was confirmed with peaks at 0.511 MeV, 1.88 MeV, 1.05 MeV, and summed peaks at 1.022 MeV and 1.077 MeV. The average half-life was 67.5 minutes. 68Ge breakthrough was less than 0.0001%. Radiochemical purity was >99.9% with the principle peak at rf = 0.0-0.2. Metal ion content for Zn2+, Fe 2+, Cu2+, Ni2+and Pd2+ was less than 1 μg/GBq for each test. Sterility tests showed no turbidity and endotoxin tests passed at < 1 EU/ml. All samples were clear, colourless and free from particles. The pH of all samples was within the range 1.0-2.0. These results confirmed that the generator had met all the criteria of the E.P. and UKRG. The RCP of subsequently prepared 68Ga-THP-PSMA for clinical use was 97±1% (n=20) with good quality images. Conclusion: All of the acceptance testing results were satisfactory and we conclude a successful validation of the generator and confirm its suitability for clinical use.


   PP2: Classification of good count and low count image using machine learning algorithm Top


Akshima Sharma, Anil Kumar Pandey, Deepak, Param Dev Sharma, Chetan D. Patel, Chandrasekhar Bal, Rakesh Kumar

All India Institute of Medical Sciences, New Delhi, India.

Aim: Principal components (PCs) of the image can be used as image feature. This study was conducted to determine the number of PCs for the classification of image into two classes: namely good count and low count and measure the performance of classification algorithm. 99mTc-MDP whole body bone scan images were used for the purpose. Materials and Methods: One hundred one patients underwent 99mTC-MDP bone scan acquisition twice at two different acquisition speeds, one at low speed and another at double the speed of first scan with patient lying in same position on the scan table. The low speed acquisition resulted in good count images and high speed acquisition resulted in low count images. The principal component analysis (PCA) of these images was performed and 2, 4, 8, 16, and 32 PCs were used as feature vectors of the image. The data was split into three sets i.e. training set and two test sets in the ratio 60:20:20. Multivariate Adapative Regression Splines (MARS) algorithm was used for training and prediction of test images. Sensitivity, specificity and accuracy for the classification of high and low count images were taken as metrics for the performance of the algorithm. Results: There was an appreciable increase in specificity (approximately equal to 10% or higher) with increase in number of PCs and was highest with 32 PCs for the classification of images. Sensitivity either remained similar, or decreased slightly with increase in number of PCs. Accuracy in classification showed an increasing trend with increase in number of PCs. Based on this study, the number of PCs for classification of images was found to be 32 and the performance in terms of specificity and accuracy was >90% and >85%, respectively. Conclusion: Thirty two feature vectors extracted using PCA can be used for classification of good and poor quality MDP bone scan images with high accuracy using MARS as the classifier. But, if in case the priority is to obtain approximately 80% of accuracy, sensitivity and specificity, then we can perform experiments even using 2 or 4 feature vectors extracted from PCA.


   PP3: Study the effect of various reconstruction parameters on positron emission tomography image quality using NEMA NU 2-2001 IQ body phantom Top


Priya, Ankit Watts, Harmandeep Singh, Bhagwant Rai Mittal

Department of Nuclear Medicine, PGIMER, Chandigarh, India.

Aim: To evaluate the effect of various reconstruction parameters on PET image quality using NEMA NU-2 IQ body phantom. Materials and Methods: A phantom study was conducted using NEMA-NU2- 2001 body phantom to study the effect of various reconstruction parameters on image quality. Phantom was filled as per NEMA guidelines with smallest four spheres filled with 18F in a concentration gradient of 4:1 that of background. While biggest 2 sphered mimicked as cold lesions. Phantom was acquired as per the routinely followed clinical protocol. Phantom study was prospectively reconstructed by varying reconstruction parameters such as Point Spread function (PSF), image smoothing filters (light, standard, heavy) and matrix size (128*128, 192*192). Data Analysis: The effect of these above parameters was quantitatively analyzed using by computing Contrast, Noise, Signal to noise ratio's (SNR), Contrast recovery coefficient (CRC), Background Variability (BV). To reciprocate the same into clinical settings, a qualitative evaluation was done in 12 lymphoma patients as function of PSF, image smoothing filters and matrix size. A visual (5 point) scoring approach was followed to rate the overall image contrast. Axial slice with smallest lesion was selected for scoring the image contrast of the lesion while a liver slice was selected for scoring the noise. Results: Phantom Study: PSF modeling significantly improved activity recovery and reduced noise. Quantitative analysis of 17 mm hot sphere between PSF vs NON-PSF images showed higher SNR values (66.04 vs 53.2), Contrast (3.72 vs3.18), CRC (61.4 vs 55.6) and lower BV (2.8 vs 3.2) & Noise (0.0407 vs 0.041) values. Matrix size of 192*192 showed higher SNR (66.04 vs 60.24), Contrast (3.72 vs 3.6) CRC (61.4 vs 60.4) and lower BV (2.8 vs 3.3) & Noise (0.0407 vs 0.043) than compared to 128*128 matrix. While no significant difference was found between various smoothing filters. Clinical Study: Similar trend was seen in the mean visual scores of 12 lymphoma patients. Patient image reconstructed with PSF showed higher mean score of 4.08 as compared to 2.83 of Non-PSF image. Mean scores of 192*192 matrix were found to be higher (4.08 vs 3.75) as compared to 128*128. Conclusion: In whole-body PET/CT hybrid imaging system, PSF-based PET reconstruction improves activity recovery and reduces image noise. In case of matrix size, 192*192 matrix showed overall better image quality as compared to 128*128 matrix. Image smoothing filters can be used as per personal preference. The results derived from phantom study can be reciprocated with confidence in clinical scenario.


   PP4: Longitudinal quality control of D-single-photon emission computed tomography Top


Aprajita Bhardwaj, Ashwani Sood, Madan Parmar, Bhagwant Rai Mittal

Department of Nuclear Cardiology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.

Aim: To do the Quality Control of D-SPECT and observe any deviations in performance over the time. Materials and Methods: Various Quality Assurance tests including the general quality controls were performed on D-SPECT- a dedicated SPECT manufactured by Spectrum Dynamics, (Caesarea, Israel) for myocardial perfusion imaging employing Cadmium Zinc Telluride detectors from its installation in October 2018 till March 2019 (a period of six months) in our department. The general performance tests covered under daily QC provided the systems homogeneity, energy peaking, detector registration and scan sensitivity and results were noted. Other tests were performed at the specified time intervals and their results were recorded, evaluated and compared with the acceptance testing results. Results: The results of QA test performed at the time of installation were under the range as specified by the company and was set as a benchmark for evaluating further QC tests that were performed during the study. Homogeneity Index (≥ 90%), Energy resolution (~ 7.5%) Detector registration (visually smooth), scan sensitivity (over 1900 counts/min/micro curies), values of system's total performance including contrast (spheres A,B,C,D showed contrast values with in limit) uniformity (97% uniform),spatial resolution (smallest reconstructable sphere of 11 mm was visible) all were under specified limits. Conclusion: All QA test values were within the specified limits and there were no major deviations observed in the performance of D-SPECT over the six months' time period.


   PP5: Tc-99m TRODAT single-photon emission computed tomography: Image based classification using ensembles machine learning algorithm Top


Madhavi Tripathi, Anil Kumar Pandey, Angel Hemron, Madhavi Tripathi, Divya Yadav, S. T. Arun Raj, C. S. Bal

All India Institute of Medical Sciences, New Delhi, India.

Introduction: Tc-99m TRODAT ([2-[2-[3-(4-chlorophenyl)-8-methyl-8-azabicyclo [3, 2, 1] oct-2-yl] methyl](2-mercaptoethyl)-amino] ethyl] amino] ethanethiolato (3-)-N2, N2', S2, S2']oxo-[1R-(exo-exo)]) binds to the dopamine transporter (DAT) and is used for the evaluation of presynaptic dopaminergic function in Parkinsonism. In this study we attempted to classify Tc-99m TRODAT SPECT images using ensembles machine learning algorithm. Materials and Methods: Ninety eight Tc-99m TRODAT SPECT studies were included for analysis. The transverse slice of SPECT images were exported in jpeg format and classified into two set of classes- one having normal scan (patient did not have Parkinson's disease) and the other abnormal scan (patients having Parkinson's disease).The feature vectors of these images were extracted using texture model of locally stationary wavelet fields. The feature vector of the labelled data set was partitioned into ratio of 80:20 as training and test data sets. The ensembles learning were performed on training data sets and the accuracy of prediction of ensemble model was evaluated on test data set. The Caret Package was used for classification task. All programming related with this study was performed by writing R script on the personal computer. Results: The accuracy of prediction of ensemble model on test data set was found to be 84.21% (sensitivity: 0.6000 and specificity: 0.9286.). Conclusion: The ensemble machine learning algorithm successfully classified Tc-99m TRODAT SPECT images with 84.21 % accuracy and inclusion of a larget test set will be useful for deciding its utility in the clinical setting.


   PP6: Comparison of gamma camera quality control procedures with IAEA-NMQC ToolKit and vendor-provided software Top


Sarita Kumari, Hariom Gupta, Subhash Kheruka, Manish Ora, Sanjay Gambhir

Department of Nuclear Medicine, SGPGIMS, Lucknow, Uttar Pradesh, India.

Aim: The aim of this study was to compare the daily quality control (QC) of gamma camera using the vendor provided Xeleris 2.01 and the IAEANM Toolkit software. Materials and Methods: We performed Gamma camera quality control on the Hawkeye-4 SPECT/CT system. The analysis of the result was done using two software Xeleris 2.01 and IAEANMQC Tool Kit. The IAEA NMQC Tool Kit of independent standard tool is important in the quality control measurements in gamma camera systems Results: There was a significant difference between the QC parameters as measured by the two software. The results of the non-uniformity analysis showed differences between the Xeleris 2.01 QC software in comparison to the IAEA NMQC toolkit were 65.62%, 50.97, 45.59% and 29.7%, for Useful field of view (UFOV) integral, UFOV differential, central field of view (CFOV) integral and CFOV differential respectively. Conclusion: The significant difference was noted in the routine daily QC results using the vendor provided Xeleris 2.01 and available IAEA NMQC toolkit. The benefit of IAEA NMQC toolkit could be for comparison different gamma camera systems in a department or in comparison to the different department of other hospitals. Therefore, it is important to perform the QC analysis by the vendor QC software as well as by independent analysis by standard software. IAEA NMQC.


   PP7: Evaluation of special features of indigenously developed thyroid uptake system by electronics division, BARC Top


Sushama Awasare, K. Biju

RMC, BARC, Mumbai, Maharashtra, India

Aim and Objective: Evaluation of Thyroid uptake system developed by BARC consists of several important and special features for performing Iodine capsule counting, perchlorate discharge test in addition to thyroid uptake calculation. Materials and Methods: Thyroid uptake system is an integral part of nuclear medicine departments for investigating thyroid function in patients. The system comprises a detector with NaI (Tl) crystal, flat field collimator, data acquisition system based on multichannel analyzer (MCA) and windows based application software. The application software has been developed with special features like energy calibration, system calibration, 131I capsule counting, automatic uptake calculation as well as report generation and printout functions. The application provides flexibility for changing the number of 131I capsules for counting, which also displays the result as accepted /rejected based on mean ± 2 SD. For uptake calculations, provision is available to calculate uptake for various doses administered to patient like 25 uCi, 1 mCi and 3-5 mCi. This software also provides the option for Perchlorate discharge test, which consists of uptake calculations at various time intervals and displays final report on monitor. Results: All the features of application software are evaluated and validated for reliable outcome. Additionally, patients' data can be stored for future archival and reports are automatically generated to take hard copy. Conclusion: The Indigenous Thyroid Uptake System developed by BARC is found very useful. Additional special features of application software facilitate to perform thyroid uptake study with much convenience. The application is user friendly and time saving and the performance of the system is comparable to other Thyroid Uptake systems presently in use at RMC.


   PP8: Extrinsic uniformity test using 51Cr flood phantom on 5/8” thick crystal single-photon emission computed tomography gamma camera mounted with medium energy collimators: A feasible approach Top


K. Biju, Sushama Awasare, Nawab Singh Baghel, Sanjay Kumar Saxena, Usha Pandey, K. V. Vimalnath, Kamaldeep, Sharmila Banerjee

Radiation Medicine Centre, BARC, Mumbai, Maharashtra, India.

Aim: To check the feasibility and validity of using 51Cr as flood source for performing uniformity test of gamma camera mounted with medium energy collimators. Materials and Methods: An indigenous phantom was designed and developed for this purpose at Radiopharmaceuticals Division, BARC. About 125 mCi of Na251CrO4 produced at BARC was used to prepare flood phantom. Activity was added to the water filled flood phantom, mixed well and kept in a proper shielding case. Uniformity test was carried out on Siemens Symbia-E 5/8” thick crystal SPECT Gamma Camera system mounted with medium energy collimators. Data was acquired for 10, 000 KCts with matrix size 256 x 256, and 15% window centered at 322 Kev. Results: A good count rate of 15-17 kcts/sec was obtained with 125 mCi flood source with medium energy collimators. The quantitative analysis was carried out for uniformity test, using automatic software available with the system. Integral uniformity was calculated as < 4.5% for both the detectors. Radiation exposure to the worker during preparation was measured to be 7uSv. Conclusion: The newly designed phantom was successfully used in our studies. Due to the longer half-life of 51Cr (28 Days), it was found to be suitable for preparing flood phantom for evaluation of extrinsic uniformity on a daily basis. It also serves as a convenient and time saving option. Further studies have to be performed to standardize this procedure.


   PP9: Evaluation of performance characteristic of GEMINI TF 16 slice positron emission tomography/computed tomography scanner at high and low count rates Top


Sutapa Rakshit, Basant Malpani, Nawab Singh Baghel, Sharmila Banerjee

Radiation Medicine Centre, BARC, TMH, Mumbai, Maharashtra, India.

Aim and Objective: The count rate performance of a PET scanner as a function of activity in the field of view has nonlinear contribution of dead-time, count pile-up and random coincidences. Adequate estimation of these nonlinear effects is essential for accurate quantification. Frequently clinical studies are performed with various amount of activity. For which count losses due to system dead time, rate of random events due to increase in single count rates are considerable and that can affect quantification. In this work our aim was to evaluate performance of GEMINI TF 16 Slice PET-CT System on high and low count rates by decaying source method. Materials and Methods: Approximately 1 mCi of 18FDG were filled in cylindrical phantom (volume approximately 10 liters, diameter × length: 20 cm × 30 cm). The radioactivity was uniformly mixed in water and air bubbles were removed. The phantom was placed in the centre of axial field of view of the PET-CT scanner. CT scan with 120 KV and 80 mAs were used for attenuation correction. Data acquisitions of the phantom were carried out at various time points (1 h, 3.5 h, 6 h, and 6.5 h). In each time point, acquisition time was kept at 120 sec/bed keeping the same geometry of the phantom. Post attenuation correction of raw data, PET reconstructions were done by row action maximum likelihood algorithm (RAMLA) and 4 mm thick transverse slices were obtained. A large rectangular box ROI of area approximately 50000 sq mm (l × b, 277 mm × 180 mm) was drawn at the coronal slice. Mean counts and area in mm was noted for each. For each time point decay correction was done. Results: The phantom was scanned at activity levels of 0.92 mCi, 0.34 mCi, 0.14 mCi & 0.11 mCi. For each set of images, the decay corrected counts/sec/μCi at various time points were found to be (963, 1002, 1034, 1021) (Average: 1005, SD: 31) for 18FDG. The ratio of observed counts/dps was found to be 0.028 for 18FDG. Conclusion: The performance of GEMINI TF 16 Slice PET-CT system showed marginal counting losses at high activity levels. It is, therefore, suggested to carry out PET/CT studies using minimum possible activity to have optimum counts with less count losses. However, further studies are to be carried out to derive a relation between activity and count loss.


   PP10: Optimization of presyringe counting time to avoid pixel saturation in modern gamma cameras: Its impact on glomerular filteration rate estimation Top


Amit Nautiyal, Viraj Sawant, Ashish K. Jha, Sneha C. Nair, Sanny Bhushan Kumar, Kevin Fonseca, Jay Prakash, Jay Kumar Rai, V. Rangarajan

Department of Nuclear Medicine, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra, Balco Medical Center, Vedanta Medical Research Foundation, Raipur, Chhattisgarh, India.

Background and Objectives: A Gamma Camera system is used to generate accurate and reproducible quantitative results in routine clinical practice. There are many factors known to affect the accuracy of results, i.e., system overall performance, dead time and acquisition and processing parameters etc. Dead time is known to influence the count rate performance of Gamma Camera at high count rate. Pixel saturation is another phenomenon which affects counting on gamma camera. In modern gamma camera the problem of pixel saturation is rarely encountered. During protocol development on newly installed gamma camera, we decided to optimize the counting time for pre and post syringe during GFR study. Aim of our study is to find adequate time duration for pre and post syringe counting and its impact on GFR results. Methods: Study was performed on GammaCamera1: Discovery NM/CT 670 Pro (GE Healthcare) and GammaCamera2: Symbia T (Siemens healthcare) installed in two different hospitals. 20 patients (45.8 ±7.99) underwent for GFR study on both the systems (10 on each). Average activity used for the GFR study was 5 mCi 99mTc-DTPA. Pre & post syringe counting was performed for 10 second and 60 second (64 X 64 matrix) in both systems. GFR was estimated using 2 sec per frame for 60 sec and 15 sec per frame for 420 sec (64 X 64). Two sets of GFR were calculated using SET_A: 10 sec syringe counts and dynamic study in GammaCamera 1 & 2 and SET_B: 60 sec syringe counts and dynamic study in GammaCamera 1 & 2 and compared. Subsequently syringe counting was performed using 5 mCi source on both cameras using 64 X 64 and 256 X 256 for 10 sec, 30 sec, 60 sec and compared with each other. A dynamic study was also performed in 64 X 64 matrix (10 sec per frame for 60 seconds) using 5 mCi source and compared. Results: The average GFR in SET_B was found to be more than SET_A on both the gamma cameras. Percentage increment in GFR was found to be 19.56% and 14.50% on GammaCamera1 and GammaCamera2 respectively. Percentage change between measured and calculated count (based on 10 sec count) for 30 sec and 60 sec in 64 X 64 matrix in pre syringe counting study were 12.04% and 27.99% on on GammaCamera1 and 19.71% and 94.65% on GammaCamera2 respectively. Percentage changes noted between dynamic summed image and static image acquired in 64 x 64 matrix for 60 sec was 22.7 %. There were no significant changes noted between measured and calculated count (based on 10 sec count) for 30 sec & 60 sec for matrix size 256 X 256. Conclusion: Count loss takes place in 30 sec and 60 sec pre syringe counting in 64 X 64 matrix due to pixel saturation where as no change is noted in 256 X 256 matrix for the same counting time. The impact of the count loss is reflected in the form over estimation of GFR in SET_B. Hence, our study suggests that the optimal counting timing for pre syringe on gamma camera is 10 sec in 64 X 64 matrix and 256 X 256 matrix as well.


   PP11: Quality assurance protocol of atomic energy regulatory board for the nuclear medicine imaging equipment Top


Namitha Krishnakumar, Pankaj Tandon, S. C. Kheruka1, Jolly Joseph

Atomic Energy Regulatory Board, Mumbai, Maharashtra, 1SGPGI, Lucknow, Uttar Pradesh, India.

Introduction: Nuclear Medicine (NM) imaging is playing a pivotal role in diagnosis of various diseases including cancer. It provides both anatomical and physiological information that cannot be obtained using other existing imaging modalities and offers the potential to identify diseases at an earliest stage. The flawless performance of Nuclear Medicine imaging equipment is of paramount importance for the accuracy of clinical diagnostic studies since any malfunction of the equipment may create image artifacts and alter the diagnosis. These malfunctions can lead to repeated imaging of the patient. AERB devised a standardised Quality Assurance (QA) protocol in order to optimise patient exposure and ensure image quality during NM imaging examinations. Materials and Methods: Several guidelines for QA of NM imaging equipment have been published by various organisations such as IAEA, AAPM, NEMA etc. However, a harmonised document covering QA protocols and the procedures to perform the QA aspects of NM imaging modalities were not available in the country. Also, QA tests were carried out as per the manufacturer's acceptance test protocol at the time of commissioning of the equipment. Therefore, a need was felt by AERB to establish a standardised QA protocol for Nuclear Medicine Imaging equipment. AERB thoroughly reviewed all the available guidelines and reports of QA, Technical Specification(s) of equipment and inputs of the manufactures /suppliers of NM imaging equipment in the country and recommended a set of tests for evaluating the characteristics of the Gamma camera /SPECT /PET imaging equipment. Process of developing QA protocol included deliberating on the test parameters along with tolerances as per international reference documents and taking into account the feasibility of testing/demonstration at the utility site. Conclusion: The recommended QA protocol was devised considering the international standards and thereby implemented as a licensing requirement by the regulatory body. The recommended tests can easily be implemented to perform the QA periodically which will not only help to comply with the regulatory requirements but also to optimise the dose to patients and obtain good quality image.


   PP12: Natural language processing tool for detecting lung cancer terms in real world radiology reports Top


Umesh Kumar Baburao Sherkhane, S. Mithun, A. K. Jha, V. Jaiswar, C. Kulkarni, A. Dekker, L. Wee, V. Rangarajan

Homi Bhabha National Institute, Tata Memorial Hospital, Mumbai, Maharashtra, India.

Aim: A large amount of potentially useful clinical information is embedded in electronic health records (EHR) in the form of free text. A variety of natural language processing (NLP) tools can be used to extract this information for the purpose of Big Data mining. One of them is cTAKES (Clinical Text Analysis and Knowledge Extraction System), an open-source NLP processor based on Parts-Of-Speech (POS) and Named Entity Recognition (NER). However, NER is known to be susceptible to out-of-vocabulary (OOV) problems when processing uncleaned radiology texts. To overcome this limitation we developed an in-house python script to add these terms to a lung cancer terminology to improve NER. Methods: We sampled 100 consecutive patients' radiology raw electronic reports from the thoracic disease management group in the year 2014. We compiled a custom terminology for lung cancer using the National Cancer Institute Thesaurus (NCIT) and including abbreviations and common typographical errors. After stop-word removal, segmentation and tokenization, were executed the script to classify the individual reports as pertaining to “Lung Cancer” or “Not Lung Cancer”. Input files were ASCII text in common formats (.txt, .csv or directly dumped from EHR). Results: We checked detection accuracy of the script by manually spot-checking 10 randomly selected reports from the processed reports. All lung cancer terms present in the report and our script identifies these terms with accuracy of 100% and recall of 1, with the caveat of the test set being very small. Along with the terms our script also determines the frequency of named entities in the report along with their corresponding NCIT unique identifier for each entity. Conclusion: In this feasibility of concept, we showed that our process with a customized terminology demonstrated good accuracy in automatically labeling lung cancer cases. The added advantage of this tool is that it can be integrated in such a way as to perform NER directly on an EHR data stream. Further study and validation is required to conclusively estimate its true accuracy and recall on previously uncleaned radiology reports.


   PP13: Performance assessment of a newly installed thin layer chromatography scanner over a period of 6 months Top


Rajesh Kumar Shasani, Sneha Mithun, Ashish Kumar Jha, Vivekanand Dube, Venkatesh Rangarajan

Department of Nuclear Medicine, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra, India.

Aim: A Thin Layer Chromatography (TLC) Scanner is utilized widely to perform radiochemical purity (RCP) to access the quality of radiopharmaceuticals. Quality control of TLC scanner is of up most importance to ensure reproducible and accurate RCP from the system. A TLC scanner was installed in our department in November 2018. As recommended we performed daily quality control of this instrument to ensure proper functioning of instrument. The aim of this study is to assess the consistency, precision and reliability of this TLC scanner by analyzing some of the daily quality control parameters of this instrument over the period of six months. Methods: This is a retrospective assessment of performance of a recently installed TLC scanner (COMECER, Model no. GAMMA BGO-V-DETECTOR, SR.No-18GY1144). Quality tests performed daily included motor test, detector efficiency test, system energy check and background test. Positioning test, efficiency test and energy test are performed to evaluate motor, detector and voltage of system respectively. Entire test duration is 17 min consisting of 2 min, 5 min, 5 min and 5 min for motor, detector, system and background tests respectively. The efficiency of the detector was performed using a 137Cs standard button source (Supplied by RPhD BARC). We retrospectively analyzed the results of these tests and selected a period of six months between January to July 2019. Total 121 quality control tests data were analyzed and mean standard deviation and variance calculated. Results: Motor test and background test were passed on majority of the occasions. On few occasions background test failed due to presence of radioactive source in the vicinity which passed subsequently on repeat test after removal of that source from the vicinity. 751.44, 1.14 and 0.15 were mean, standard deviation and variance for energy check of the system respectively. Similarly 5.24, 0.52 and 9.89 were mean, standard deviation and variance for efficiency of the detector respectively. Conclusion: Our study shows that overall performance of this TLC scanner is consistent and reliable over the period of 6 months.


   PP14: Selecting radionuclide-collimator pair on GE discovery NM670 pro progamma camera based on Monto Carlo simulation approach Top


Viraj V. Sawant, Jay Prakash Kumar, Ashish K. Jha, M. Sneha1, Amit Nautiyal, V. Rangarajan

Department of Nuclear Medicine, Tata Memorial Hospital, 1Homi Bhabha National Institute, Mumbai, Maharashtra, India.

Objective: Gamma camera is one of the oldest and most important equipment used in nuclear medicine. Image quality and quantitative accuracy of gamma camera are affected by collimator septal penetration, hole size, hole length and scatter fraction particularly in high energy imaging. In addition, the presence of penetrated and scattered photons degrades the image quality. The knowledge of septal penetration and scatter fraction as a function of photon energy is essential for the choice of imaging protocol and collimator. The goal of our study was to compare radionuclide collimator combination based on resolution and other parameters using onto Carlo simulation technique. Materials and Methods: We used SIMIND Monto Carlo programme for our study. SIMIND is mainly design to simulate clinical scintillation camera and SPECT system. With simple modification, it can be utilized to simulate any type of imaging or quality control tests of SPECT. In our study, we simulated point source using SIMIND for experimental characterization of Discovery NM/CT 670 PRO Gamma camera, GE Medical system. The simulations carried out for the different collimators LEHR, MEGP, HEGP with three different radioactive sources i.e. 99mTc, 177Lu and 131Iodian. Simulated point source images were process on Xeleris Workstation, GE Medical system to obtain FWHM and FWTM. FWHM and FWTM calculated by imaging point source and compared with that of simulated data. Imaging characteristics i.e. sensitivity, resolution and septal penetration of each radionuclide collimator pair were compared. Results: Simulation based performance characteristic i.e. FWHM, FWTM, sensitivity and septal penetration for combination of collimators i.e. LEHR, MEGP, HEGP and radionuclide i.e. 99mTc, 177Lu and 131I shown in Table 1. Comparison of FWHM and FWTM obtained from simulated and experimental images shown in Table 2. From Table 2 the resolution of the LEHR is better compare to both MEGP and HEGP for low energy radionuclide. For LU177 % of penetration is 75% less than LEHR where it almost same for both MEGP and HEGP. With MEGP Resolution is 32% better than HEGP. For high energy, HEGP has least % of penetration compare to both LEHR and MEGP resolution for I131 energy. Conclusion: For low energy radionuclide, LEHR is always best choice with its resolution because of no significant penetration at lower energies. For medium energy, radionuclide compare to % penetration and resolution MEGP gives better result. As for high photon energy radionuclide due its larger penetrating ability, HEGP is always a good choice of collimator.


   PP15: Comparing of lutetium-177 whole body imaging on different collimators using SIMIND Monte Carlo simulation by modelling a GE NM 670 Pro single-photon emission computed tomography/computed tomography scintillation camera Top


Jay Prakash Kumar, Viraj Sawant, Ashish K. Jha, Sneha Mithun, Amit Nautiyal, Venkatesh Rangarajan

Department of Nuclear Medicine, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra, India.

Aim and Objective: Lutetium (Lu)-177 is one of the radioisotopes for peptide receptor radionuclide therapy using the theranostics approach. For Lu-177 imaging, the selection of type of collimator, gamma ray energy and energy window setting can be validated by using Monte Carlo (MC) simulations. SIMIND is one of the Monte Carlo simulation tool used to simulate planner as well as single photon emission computed tomography (SPECT) studies. Gamma Camera is subjected to various detector and electronic related challenges, which may impair the image quality. Hence, it's imperative to validate the image quality of gamma camera using MC program. In this study, we simulate a Lu-177 whole body planar imaging on three different collimators like low energy high resolution camera (LEHR), medium energy general purpose collimator (MEGP) and high energy general purpose collimators (HEGP) with use Monte Carlo program and compare the all simulated planar images with real gamma camera image, imaged on Discovery NM 670 Pro SPECT/CT, GE medical system. Methods: SIMIND can be configured to simulate specific SPECT system. SIMIND system consists of two main programs, CHANGE program and the SIMIND simulation program. First, we verified SIMIND MC software. We entered Discovery NM 670 Pro SPECT/CT, GE medical system parameter in the SIMIND and simulate point source and acquired a real gamma camera point source image. Subsequently a point source of 1.0 mm x 1.0 mm x 1.0 mm using Lu-177 (3.7 MBq) isotope energy, positioned at the centre of the field of view (FOV), 12 cm from the detectors was simulated using SIMIND MC software. A gamma camera imaging was performed using the parameter, aforementioned. Simulated as well as acquired images were transferred on Xeleris 4.0 workstation and calculate FWHM and FWTM by the method of point spread function, results were compared. Secondly, we simulate a Lu-177-DOTA-TATE WB image on three different collimators like LEHR, MEGP, HEGP. For this simulation, we use NCAT phantom and change zub file of mdp_wb as per bio-distribution of Lu-177-DOTA-TATE. Simulate images in .hoo files were converted into DICOM file by XMedcon software. Subsequently, simulated image in DICOM format were transferred to Xeleris workstation. Simulated whole body images and one patient's acquired images were processed on Xeleris work station and visually evaluated. Results: The FWHM and FWTM of point source with MEGP collimator were 6.8 mm and 12.24 mm for simulated and 7.3 mm and 13.14 mm for experimental data. The system sensitivity values for simulated and experimental for MEGP were 13.0 cpm/μCi and 15 cpm/μCi respectively. Conclusion: Our study suggests that the MEGP simulation and experimental image of Lu-177-DOTA-TATE are better in comparison of LEHR and HEGP simulated image. All the simulated images and acquired MEGP images are shown in Figure 1.


   PP16: Performance assessment of thyroid uptake probe over a period of 1 year Top


Abdul W. M. Saikh, Ashish Kumar Jha, Sneha Mithun, Rajesh Kumar Shasani, Chetan R. Gupta, Venkatesh Rangarajan

Department of Nuclear Medicine, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra, India.

Aim: Thyroid uptake probe is important equipment used to assess thyroid function using radioisotope. Reliability of this equipment is ensured by performing quality check of the equipment. New generation thyroid probe comes with daily quality control protocols. We perform daily quality control of the probe every morning before clinical use. Aim of our study was to assess the stability of the equipment by analyzing daily quality control data. Methods: Captus ® 4000e Thyroid Uptake System, Capintec, Inc., NJ, USA was installed in our department in year 2013. Energy resolution, Energy peaking, Linearity test and Constancy test are performed under daily quality control by using two standard sources i.e. Cs-137 and Eu-152 [Characteristics of radioisotope is given in [Table 1]. These tests are performed in this equipment regularly before clinical use and data is stored in electronic format. We retrospectively analyzed last one year's (from Sept 2018 to Aug 2019) daily quality control data. Randomly two day's daily quality control data were selected from every week and statistically analyzed to access the performance of the equipment. Results: Total 104 observations were included in this study. Equipment passed all the quality control tests including Linearity test and Constancy test on all the occasions. Average, standard deviation, and variance in energy resolution, energy peak and counting rated is shown in [Table 2]. Conclusion: Our study suggests that, the overall performance of this Thyroid uptake probe was consistent and reliable over the period of one year even after several years of use.
Table 1: Characteristics of radioisotope

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Table 2: Variance in energy resolution

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   PP17: Study of radiochemical purity analysis of 68Ga-Labeled and 177 Lu-Labeled radiopharmaceuticals performed on two different Radio-TLC scanners radiation Top


Digvijay Damodar Borade, Ashish Jha, Sneha Mithun, Ravi Yadhav, Uddesha Jha, Bhausaheb Valve, Gayatri Meena

Department of Nuclear Medicine, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra, India.

Aim: Radiochemical purity (RCP) test is one of the important tests under the quality assurance program in nuclear medicine. TLC scanner is used widely to estimate RCP of radiopharmaceuticals. These TLC scanners have various kinds of detectors i.e. NaI(Tl), BGO and plastic used for radiation measurement. Several radiopharmaceuticals are prepared in hospital radiopharmacy and cyclotron facility, which is used for diagnostic and therapy purpose. These radiopharmaceuticals are labeled by various isotopes having low to high energy gamma emitters, pure beta, positron or alpha emitters. Performance of detectors varies as per the characteristics of radioisotope used. Hence, performance of detectors used in TLC should be established before selecting detectors for RCP test of particular radiopharmaceuticals. Our aim of the study was to find most suitable detector to perform RCP for Ga-68 and Lu-177 based radiopharmaceuticals. Methods: Recently two TLC scanners, COMECER (Model no.: TLC 204 - Gina Star TLC Scanner) (Scanner:A), Eckert & Ziegler (Model no.: TLC Scan-GMD-Soft PLC viewer) (Scanner:B) were installed in our intuition. Scanner: A has one detector, namely, BGO (Bismuth Germanate (Bi4Ge3O12). Scanner:B has two detectors, namely, Plastic Scintillator and NaI(Tl). We performed RCP test of 68Ga- labeled Radiopharmaceuticals (68Ga-DOTA-NOC and 68Ga-PSMA-11) Lu-177- labeled Radiopharmaceuticals (177Lu-DOTA-TATE). ITLC-SG strip (8 cm, length of strip) was used as stationary phase and freshly prepared 0.1M sodium citrate buffer was used as mobile phase to perform TLC for all radiopharmaceuticals. Total scan time for RCP set to 5 min in all three detectors. Same ITLC-SG strip was scanned under all three detectors and RCP, product peak count and product FWHM were calculated and compared. Mean and standard deviation of RCP, peak count and FWHM were compared across the detectors. Results: Plastic detector performed better in comparison with two other detectors. The FWHM of product peak for NaI(Tl) and BGO detectors were 32% and 63% more in comparison of Plastic detector for Ga-68 radiopharmaceuticals. Similarly, the FWHM of product peak for NaI(Tl) Detector and BGO were 32% and 63% more in comparison of Plastic detector for Lu-177 radiopharmaceuticals. The mean and standard deviation of RCP, peak count and FWHM were shown in [Table 1]. Conclusion: Our study shows that TLC performs better with plastic scintillation detector in comparison of two other detectors for Ga-68 as well as Lu-177 radiopharmaceuticals.
Table 1: The mean and standard deviation of RCP, peak count and FWHM

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    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10], [Table 11]



 

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