Year : 2011 | Volume
: 26 | Issue : 5 | Page : 26--33
|How to cite this article:|
. PET-CT.Indian J Nucl Med 2011;26:26-33
|How to cite this URL:|
. PET-CT. Indian J Nucl Med [serial online] 2011 [cited 2020 Dec 2 ];26:26-33
Available from: https://www.ijnm.in/text.asp?2011/26/5/26/90731
Role of Gallium-68 labelled dotanoc PET/CT in evaluation of neuroendocrine tumor
Chhavi Gupta, Promila Pankaj, Ritu Verma, Ethel S Belho, Shashwat Verma,Sugandha Dureja, Harsh Mahajan
Department of Nuclear Medicine, Sir Gangaram Hospital, New Delhi, India
Introduction: Neuroendocrine tumors (NETs) are a heterogeneous group of neoplasms occurring in 1 to 4 per 100,000 people per year.These tumors originate from pleuripotent stem cells or differentiated NE cells. The characteristic of these neoplasms is that they express several different peptide receptors in high quantities. Conventional imagining techniques like USG, CT, MRI are often insufficient to make conclusive diagnosis of NET. For general oncological imaging, positron emission tomography (PET) using [ 18 F]fluoro-deoxy-glucose (FDG) has evolved as a powerful functional imaging modality. Unfortunately, FDG-PET has not been as advantageous for imaging neuroendocrine tumors, and only tumors with high proliferative activity and low differentiation have shown an increased FDG uptake thus it present a low sensitivity for the detection of NET. Molecular imaging exploits the high expression of this G protein-coupled receptor i.e. somatostatin receptors (SSTRs) in many neuroendocrine tumors. Aim and Objective: The aim of this study is to evaluate the diagnostic value of a new somatostatin analog Gallium-68 labeled DOTA -NOC (1, 4, 7, 10 -tetraazacyclododecane-1, 4, 7, 10 tetraacetic acid with 1 -Nal3 octerotide) for PET CT scan in neuroendocrine tumor. Materials and Methods: 24 patients were prospectively studied. Each patient were injected with 2-3 milicurie Ga-68 DOTA-NOC. Whole body PET- CECT scan was performed after 45-60 minutes with the GE Discovery STE PET/CT system. High resolution CT scan was also performed using dedicated PET scanner with 32 slice /sec Multidetector Computerized Tomography (MDCT). Results: Patients were divided into 2 groups localisation of unknown site of primary tumor in the presence of clinical or biochemical parameter suggestive of Neuroendocrine malignancy (n=15) primary tumor staging of known neuroendocrine tumor cases (n=9) 13 out of 24 cases show Ga-68 labelled DOTANOC avid lesions. In first group, 6 cases were positive on Ga-68 DOTA-NOC PET- CT scan indicating primary site of tumor. 2 cases showed non DOTANOC avid lesions but significant uptake of FDG on subsequent FDG PET Scan indicating SRS receptor negative (poorly differentiated tumor). In second group, 7 cases were positive displaying metastasis. 1 case again showed non DOTANOC avid lesions but significant uptake of FDG on subsequent FDG PET Scan indicating SRS receptor negative (poorly differentiated tumor). Conclusion: Ga-68 DOTANOC PET/CT is a potentially useful tool for the detection of unknown primary site of NET and for staging the extent of disease.and should be included in the diagnostic work-up of these patients.
Metastases to left calf muscle from carcinoma esophagus - a rare presentation
Abhishek Khare, Vishal Aggarwal, Surbhi Pande, Ashok Sen, Dhanraj Jangid
Department of Nuclear Medicine and PET-CT, Medanta - The Medicity, Sec-38, Gurgaon (Haryana), India
Introduction: Skeletal muscle metastases from carcinoma esophagus is a uncommon finding. There are very few cases reported in literature where muscle metastases to distant muscle, have been detected and histopathologically proven. Metastases to skeletal muscles accounts for less than 1% of hematogenous metastases from solid tumors. We present a case of moderately differentiated squamous cell carcinoma (MDSCC) esophagus presenting as metastases to left gastronnemius muscle. Case summary: A 73 year old male, a case of MDSCC middle 1/3 rd esophagus status post chemoradiotherapy completed in jan 2011. PET-CT scan done in may 2011 revealed complete morphological and metabolic regression. The patient presented for Follow-up PET-CT scan in oct 2011. The patient was asymptomatic except for nagging pain in the left calf for past 3-4 months. In view of his pain in left calf, 18 F-FDG PET-CT whole body scan was done from head to toe. The scan revealed a large metabolically active hypodense nodular growth involving left lateral wall of mid-esophagus, but not causing lumen compression. Also metabolically active muscle deposits were identified in left paraspinal muscles at LV-2 level and the lateral head of the left gastrocnemius muscle. A CT guided percutaneous biopsy from the left gastrocnemius and paraspinal muscles at LV-2 level was performed and they revealed intramuscular deposits of a moderately differentiated squamous cell carcinoma, consistent with primary esophageal cancer. Case discussion: skeletal muscle account for approximately 40-50% of the total body mass and also receive a large portion of cardiac output. However the reasons why skeletal muscle metastases is rare, is not known. Probably factors such as blood flow, muscle contraction, high lactic acid causing changes in pH may not be conducive environment for tumor implantation.
Comparative study betweenTc99m-ECD and 18 F-FDG in evaluation of dementia
Parul Gupta, Madhavi Tripathi, Abhinav Jaimini, Maria D'Souza, Santosh Pandey, Sanjeev Saw, Harish Rawat, Nitin Kumar, AK Mishra, Rajnish Sharma, Anupam Mondal
Department of PET Imaging, Institute of Nuclear Medicine and Allied Sciences, New Delhi, DCRS, INMAS, Delhi, India
Introduction: Metabolic and perfusion reductions in the parietotemporal cortex are recognized as a diagnostic pattern for AD. Structural MRI and functional imaging by SPECT as well as 18 F-FDG PET are widely used in the diagnosis of Alzheimer's disease (AD). Outstanding progress in the diagnostic accuracy of these modalities has been achieved with statistical analysis (on a voxel-by-voxel basis after anatomic standardization of individual scans to a standardized brain volume template) instead of visual inspection or a volume-of-interest technique. In a very early stage of AD, this statistical approach revealed losses of gray matter in the entorhinal and hippocampal areas and hypometabolism or hypoperfusion in the posterior cingulate cortex and precuneus. This statistical approach also offers a prediction of the conversion from mild cognitive impairment (MCI) to AD. The presence of hypometabolism or hypoperfusion in parietal association areas and entorhinal atrophy at the MCI stage have been reported to predict a rapid conversion to AD. A recent advance in voxel-based statistical analysis has markedly enhanced the value of brain perfusion SPECT in diagnosing early AD at the stage of MCI. Materials and Methods: Eleven patients of dementia have been included in the study so far. All the patients underwent 18 F-FDG PET/CT and Tc99m-ECD SPECT scans. Scans were done on two different days. 10 mCi 18 F-FDG was injected intravenously and images acquired on the PET/CT scanner after 45 min. Next day 20 mCi of Tc99m-ECD was injected intravenously and SPECT images were acquired after 30 min. Results: Accumulation of 18 F-FDG was assessed visually and using the SUV values. Assessment of Tc99m- ECD was done using Talaraich stastical method. The results were then compared. Both 18 F-FDG and Tc99m- ECD show reduced tracer uptake in identical regions, at the site of involvement in the brain in cases of dementia in all the patients. No discrepancy was noted in the results of SPECT and PET images in the studies performed. Conclusion: Our preliminary study reveals that Tc99m- ECD can be used as an alternative tracer to 18 F-FDG in diagnosing early AD at the stage of MCI. Further studies are being undertaken at our institute to validate our results.
FDG PET changes in brain glucose metabolism in dementa
Rajnish Sharma, Madhavi Tripathi, Maria M D'Souza, Abhinav Jaimini, Puja Panwar 1 , Sanjeev Saw, Santosh Pandey, Dinesh Singh, Yachna Solanki, Nitin Kumar 1 , Sachin Soni 1 , Anil K Mishra 1 , Anupam Mondal
Division of Pet Imaging, Molecular Imaging Research Center, Inmas, Delhi, 1 Division of Cyclotron and Radiopharmaceutical Sciences, Molecular Imaging Research Center, inmas, Delhi, India
Introduction: The clinical identification and differential diagnosis of dementias is specially challenging in early stages. A variety of neurodegenerative disorders produce significant abnormal brain function which can be detected using FDG PET scan even when no structural changes are noted on on CT or MRI Scan. Objective: A study was undertaken at our institute to evaluate the FDG PET-CT findings in Mild Cognitive impairment (MCI), Alzheimer's disease (AD), fronto - temporal dementia (FTD), dementia with Lewy body disease (DLBD) and other miscellaneous causes of dementia. 0 Materials and Methods : 117 0 subjects having Neurocognitive deficits were included in our study. All patients underwent a detailed history and clinical examination. This was followed by a Mini Mental State Examination (MMSE). Subsequently an FDG brain PET scan and an MRI were done. Results : 0 In the patient population included in our study group 36 were normals, 39 had MCI, 40 had AD, 14 had FTD, 13 had DLBD and 11 dementia due to other miscellaneous causes. MCI patients showed primarily reduced tracer uptake in the mesio - temporal cortex. AD patients showed reduced tracer concentration in temporo - parietal lobes, while patients with advanced diseases showed frontal lobe disease additionally. In subjects of FTD, reduced radiotracer uptake in the fronto-temporal lobes was noted. In addition, FTD patients also showed basal ganglia defects. In contrast the DLBD patients showed globally reduced FDG uptake including the occipital cortices. Conclusion : 0 In the current study the F 18 - FDG PET scans have been shown to be highly useful in the diagnosis of various neurocognitive disorders of the brain. Alzheimer's disease was found to be the most common dementia in the Indian population. The second most common dysfunction was attributed to Mild Cognitive Impairment (MCI). Diffuse lewy body disease, fronto temporal dementia and other miscellaneous categories of dementia had a near similar incidence.
Comparison of C-11 methionine and 18 F-FDG PET imaging for brain tumour-a perspective pilot study
Romana Sehar, Madhavi Tripathy, Maria D'Souza, Abhinav Jaimini, Sanjeev Saw, Santosh Pandey, Rajnish Sharma, Anupam Mondal
Division of Clinical PET & DCRS, INMAS, Delhi, Delhi State Cancer Hospital, DSCI, Shahadra, Delhi, India
Introduction: sComparative evaluation of c-11 Methionine (MET_PET) and 18 F-Flourodeoxyglucose (FDG) PET/CT for detection of recurrent brain tumors. Materials and Methods : 0 23 post-operative histologically proven cases of primary brain tumors were included; there were two cases of grade I (WHO),9 cases of grade II,5 cases of grade III,3 cases of grade IV,3 Medulloblastomas and one gliosarcoma.Ratio of M:F=16; 7, age 27.5 + 14.4 years (range 5-56 years). All patients underwent the MET-PET and FDG-PET scans on the same day.Images were evaluated for recurrence using visual analysis and final results were compared with MRI/MRS and follow up as gold standard. Results: Fourteen cases were positive for recurrence on the MET-PET study while FDG 0 was unequivocally positive in eleven cases.MET-PET scans were true negative for recurrence in nine cases and concurrent with the MRI/MRS findings in all 23 cases.tumor to background ratio for the MET-PET study were 2 .2 + 0.55. 0 Conclusion : 0 MET-PET is superior to FDG-PET for detection of recurrence in both low and high grade gliomas and has excellent correlation with MRI/MRS.
Evaluation of recurrent brain tumors in low grade primary gliomas with 18 F-FDOPA PET-CT, 18 F-FDG PET-CT, Tc99m-GHA SPECT-CT and MRI
Karunanithi Sellam, Bal CS, Gupta D 1 , Malhotra Arun, Kumar Abhishek, Kumar Rakesh, Bandopadhyaya GP
Departments of Nuclear Medicine and 1 Neurosurgery, AIIMS, New Delhi, India
Objectives: Aim of this study was to evaluate and compare the role of four different imaging modalities namely 18 F-FDOPA PET-CT (FDOPA), 18 F-FDG PET-CT (FDG), Tc99m-GHA SPECT-CT (GHA) and MRI in detection of recurrence in patients with low grade primary glioma. Importance of the Study: From the management point of view, low grade gliomas especially Grade II glioma needs top most attention, which can gradually transform to anaplastic grade. So the optimal treatment of the residual tumor before anaplastic transformation with early detection and treatment of recurrence in this group is of utmost importance, which can save the patient's life. Materials and Methods: Fourteen patients of clinically suspected recurrent glioma of varying low grades (three with WHO grade I and eleven with WHO grade II primary tumor), previously treated with surgery and/or radiotherapy were evaluated using FDOPA, GHA, FDG and MRI imaging. FDOPA and FDG images were interpreted positive for any abnormal tracer uptake noted in brain parenchyma. GHA images were interpreted as positive for abnormal tracer uptake noted in brain parenchyma. Final outcome was judged on the basis of biopsy report and/or clinical follow-up for a period of one year. Results: Ten patients were considered positive (death due to progression in 3, biopsy proven in 3 and clinical deterioration in 4) while 4 were negative for recurrence and patient is doing well in one year follow up. FDOPA scan was positive in 11, negative in 3 patients. GHA was positive in 9, negative in 5 patients. FDG scan was positive in 1, negative in 13 patients. MRI was positive in 6, negative in 2 and equivocal in 6 patients. For FDOPA the average T/S (tumor vs. striatum) ratio in positive cases: Mean=0.92±0.17, Median 0.92 (range 0.51-1.25), average T/W (tumor vs. White matter) ratio in positive case: Mean=2.58±0.71, Median 2.50 (range 1.33-4.53) and average T/B (tumor vs. background) ratio in positive cases: Mean=2.32±0.55, Median 2.40 (range 1.33-3.40). For GHA average T/B ratio in positive cases: Mean=4.83±1.05, Median=4.45 (range 1.6-9.17). Conclusion: (1) FDOPA was found to be superior compared to other three imaging modalities in detecting low grade recurrent/residual viable gliomas. (2) FDG has a very low detection rate in low grade recurrence but has a prognostic value in detecting recurrence in initial low grade glioma which can gradually transform to anaplastic grade in recurrence. (3) GHA had 2 false negative and one false positive result. It's a cheaper alternative to FDOPA and found superior especially in tumors located adjacent to basal ganglia.
Assessment of cancer therapy: FDG vs FLT
Seyed K Imam, Tarek El-Maghraby
Saad Research and Development Center, SAAD Specialist Hospital, Al-Khobar-31952, Saudi Arabia
Introduction: 18 F-FLT ( 18 F-3'-deoxy-3'-fluorothymidine) is a potential marker for monitoring tumor response to anti-proliferative (radio/chemo-) therapy in a variety of malignancies. Objective: To provide a better and more efficient cancer treatment by carrying out clinical studies with 18 F-FLT which can quantitatively measure the effectiveness of cancer therapy. This shall be helpful in deciding continuity or modification of the treatment plan given to the patient with minimum delay. This modality shall also optimize treatment of critically ill cancer patients and reduce significant side effects from chemotherapy if proved to be ineffective. Materials and Methods: 18 F (fluoride) is produced on Siemens 11 MeV Eclipse HP cyclotron followed by cGMP-compliant synthesis of 18 F-FLT on Explora-GN based on nucleophilic radiofluorination of FLT precursor (3-N-Boc-5'-O-dimethoxytrityl-3'-O-nosyl-thymidine) with anhydrous 18 F-fluoride using a phase transfer catalyst Cryptand or Kryptofix-2.2.2 with K 2 CO 3 (K+/K2.2.2). Once the 18 F-FLT passed all the tests, patients were injected intravenously with a specified dose (usually 10-15 mCi for an adult) and imaged 60 minutes post-injection on Siemens Biograph PET-CT scanners. The evaluation of the cancer therapy protocol was based on various imaging, clinical and laboratory markers in comparison with the results of the 18 F-FLT imaging. Results: 18 F-FLT provided superior images delineating the early effects of treatment in different tumors particularly in areas where the physiological uptake of 18 F-FDG obscures the lesions. The results of this protocol will be crucial for the management of cancer patient. Conclusion: 18 F-FLT can be a promising surrogate marker of proliferation during cancer therapy. The optimization of treatment will save time and reduce the cost of chemotherapy significantly as it will guide when the treatment is sufficient or needs to be changed before reaching end of the chemotherapy protocols.
PET/CT imaging using half the recommended activity
Mithun Sneha, Monteiro P, Shetye B, Jha A, Shah S, Agarwal A, Purandare N, Rangarajan V
Department of Nuclear Medicine, Tata Memorial Centre, Parel, Mumbai, India
Introduction: According to regulatory norms, in a PET/CT patient waiting room there should be 1.5 meter space between any two injected patients. This restricts the number of patients who can be injected and shortens the interval between injections. With time of flight PET scanners being used, there is significant reduction in injected dose or scanning time. This requires a relook into workflow and the dose of isotope used. Objective: To see impact on effective dose and work flow in a PET/CT facility with reduction of injected dose to half the recommended dose. Materials and Methods: We evaluated 22 patients in this study (11 males, 8 females, 3 children less than 12yr old). All the patients except one weighed less than 80 kg. All pregnant and diabetic patients with uncontrolled sugar levels were excluded. 10 patients were injected with half the recommended dose (2.5MBq/kg body weight). The dose rate at 1metre distance was measured immediately post injection and 1hr post injection using a survey meter. Results: The average dose rate at 1metre at the time of injection with regular and half dose were 5.72±0.74mR/h and 3.08±1.2mR/h respectively. The 1hr post injection the average dose rate at 1metre distance of the adult patients injected with recommended dose was 2.142±1.045mR/h, while those patients injected with half the dose had dose rate of 1.135±0.28mR/h. Two of the three children included in the study showed an 3.65±0.49mR/h average dose rate at 1mt immediately after injection and 1.15±0.35mR/h 1hr post injection. One child was injected with half the recommended activity and 1metre dose rate immediately after injection was 2.6mR/h and 0.97mR/h at 1hr post injection. The images acquired were found acceptable by the Nuclear Medicine Physicians. Conclusion: This study suggests that dose reduction reduces the radiation exposure to the patient and personnel. This may impact the planning of work flow. There appears to be a possibility of relaxation of norms of space requirements in departments housing time of flight systems, due to the demonstrated advantage of lower tracer dose.
Assessing the diagnostic utility of 18 F-FDG pet in carcinoma of unknown primary
Avani Jain, Shelley S, Indirani M, Alok Pawaskar, Madhur Kumar Srivastava
Apollo Hospitals, Chennai, India
Introduction: Carcinoma of unknown primary accounts for 2-9% of all malignant cases. The common presentation of these cases is lymph nodal enlargement, most commonly in the cervical region. Identification of the primary site of malignancy has a great impact on the treatment protocol and has a prognostic significance. Intensive diagnostic work up is required for identifying primary site and FDG PET-CT is one of the imaging modality used. The sensitivity of FDG PET/CT has been described to vary between 10-70% in the literature. We present here our experience in detecting occult primary tumours. Objective: To evaluate the diagnostic yield of 18 F-FDG PET in identification of occult primary tumours. Materials and Methods: We evaluated retrospectively 47 patients (male-29, female-18) with histologically proven metastasis and unknown primary. All the patients underwent whole body 18 F-FDG PET-CT with standard protocol on Philips GEMINI TF PET-CT scanner with time of flight imaging. PET-CT images were acquired from skull base to mid thigh after 60 minutes of intravenous administration of 185-245 Mbq of 18 F-FDG. 64- Slice contrast enhanced CT was used for diagnostic purpose and anatomic correlation. PET-CT findings were confirmed by follow up and/or biopsy. Results: In 39/47 patients (70.2%) PET-CT revealed the site of probable primary: lung (7), liver (2), ovary (2), sigmoid colon (3), gall bladder (4), pancreas (2), recto sigmoid junction (2), breast (1), cervix (1), kidney (1) and head and neck (14). Histopathological examination confirmed the site of primary malignancy in 33 patients. In remaining 6 patients the uptake was physiological, thereby being falsely positive. Hence overall in 33/47 patients (70.2%) PET was useful in diagnosing primary tumour. In 8/47 patients, PET-CT did not contribute to the detection of occult primary cancers. Conclusion: PET-CT was helpful in detection of occult primary in 33/47 patients (70.2%). Hence we recommend its use an initial investigation for detection of carcinoma of unknown primary.
Comparative study between Tc-99m labelled Methionine and C-11 Methionine in detection of low grade astrocytoma
Pradeep Kumar Thapa, Madhavi Tripathi, Abhinav Jaimini, Maria D'Souza, Krishna Chouttani, Santosh Pandey, Romana Sehar, Harish Rawat, AK Mishra, Rajnish Sharma, Anupam Mondal
Department of PET Imaging, Institute of Nuclear Medicine and Allied Science, New Delhi, DCRS, INMAS, Delhi, India
Introduction: Comparative study between Tc-99m labelled Methionine and C-11 Methionine in detection of low grade astrocytoma. Objective: Studies were undertaken after labeling Methionine with generator produced Tc-99m for its possible use in brain tumor imaging. Since non-availability of cyclotron in many centres in India is a concern, so Tc-99m MET can prove to be a useful adjunct to C-11 Methionine in such a scenario. The aim of this study was to compare C-11 Methionine and Tc-99m Methionine radiopharmaceutical in evaluation of residual/recurrent brain tumor. Materials and Methods: 14 patients post treatment for primary Brain tumor have been included in the study. All the patients underwent C-11 MET PET/CT and Tc-99m labeled Methionine SPECT/CT scans. Scans were done on two different days. 20 mCi C-11 MET was injected intravenously and images were acquired on PET/CT scanner after 20 min. Next day 20 mCi of Tc-99m MET was injected intravenously and planar/SPECT images were acquired after 1 hr, 2 hr and 3 hr. Results: Accumulation of C-11 Methionine images was assessed visually and by calculating SUV values of the lesions. Assessment of Tc-99m Methionine images was done visually and by using tumor to background ratio and results were compared. Both C-11 Methionine and Tc-99m Methionine were found to show tracer accumulation at the site of residual or recurrent tumor in all the cases included in the study. Conclusion: Our preliminary study reveals that Tc-99m Methionine can be used as an alternative tracer to C-11 Methionine in the evaluation of brain tumor suspected of residual or recurrence. Further clinical trials shall be done at our institute in this field to validate our results.
Recurrence detection of ewing family of tumors with 18 F-FDG PET/CT
Bangkim Chandra Khangembam, Manas Kumar Sahoo, Abhinav Singhal, Varun Singh Dhull, Sudhir Suman KC, Krishan Kant Agarwal, Ramya Soundar, Niraj Naswa, Rakesh Kumar, Chandrasekhar Bal Arun Malhotra
Department of Nuclear Medicine and PET, AIIMS, New Delhi, India
Introduction: Ewing family of tumors (EFT) affect bones, soft tissues and lungs. They are considered to arise from neuro-ectoderm and commonly affect young children and adolescents. Patients with metastatic or recurrent disease carry a worse prognosis and hence, early detection of metastases or recurrence is of utmost importance, as undetected it may alter the proper management and subsequent prognosis. Objective: The purpose of the study was to detect recurrence in patients of EFT who had been previously treated with multimodality therapy in the form of surgery, chemotherapy or radiotherapy using 18 F-FDG PET/CT. Materials and Methods: Retrospective analysis was done in 25 consecutive patients (20 males, 5 females; age range 2- 47 years, median age 23 years) of EFT who had been referred for 18 F-FDG -PET/CT for suspicion of recurrence. Results of 18 F-FDG -PET/CT were assessed visually and semi-quantitatively. Correlative imaging, clinical follow-up and/ or biopsy results whenever available were used as the reference standard. Results: 18 F-FDG -PET/CT was considered to be positive in 12 patients. 10/12 patients were considered to have true positive results based on reference standard while it was false positive in two. A total of 11/25 patients were defined to have recurrence based on reference standard and so 18 F-FDG-PET/CT was considered false negative in one patient. In addition, 18 F-FDG-PET/CT could detect metastases in 5 patients who had recurrence. SUV max of the true-positive primary lesions ranged from 1.3 to 4 with a median value of 2.4. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18 F-FDG-PET/CT were calculated and came out to be 90.9%, 85.7%, 83.3%, 92.3% and 88% respectively. Conclusion: 18 F-FDG-PET/CT is a sensitive and specific modality for the detection of recurrence in patients with EFT. 18 F-FDG-PET/CT could be a very powerful non-invasive modality for the detection of recurrence in patients with EFT.
Justification of routine WB FDG PET with dual phase Contrast CT in head and neck cancers
KM Lakshmipathy, K Alfred Deepak, AC Suresh Kumar, Rajkumar, Domnick, Srinivasan, Surendran, K Krishnakumar A Vasanthan, TG Sagar, TS Swaminathan, K Thayalan, TG Govindarajan
PET-CT Center, Unit of Dr. Kamakshi Memorial Hospital, Cancer Institute,Canal Bank Road, Gandhi Nagar, Adyar, Chennai, India
Aim: The aim of our study is to demonstrate the justification of routine WB FDG positron emission tomography (PET) with dual phase contrast CT and to know the significant contribution of them to evaluate in all stages of the primary head and neck cancers (HNC). Materials and Methods: We have included all HNC patients with WB FDG PET with dual phase contrast CT protocol, included 2 separate CT scans in the arterial contrast enhancement phase (90 mL at 2.5-2.8 mL/min. bolus tracking, scan range, base of the skull to the kidneys) and the portal-venous contrast enhancement phase (delay, 90 s. scan range, base of the lungs to the proximal thighs) during shallow breathing followed by a low-dose CT scan during shallow breathing for attenuation correction and whole-body PET included all the cases of HNC. We have recorded independently the findings of PET and Contrast Enhanced (CH)CT, later both were fused in the final report are analysed. Analysis and Results: All of our Patients happen to be males only, age range from 17 year to 82 years, 20 cases were known primary HNC and 8 cases were unknown primary. Patients data including PET SUV and CH CT status were analyzed for primary tumor(T), LymphNode (N) and distant metastasis(M) elsewhere in the body in pre and post treatment catagorised in to Group A and Group B respectively and evaluated further respect to change in the SUV,size of the lesions. Staging: PET/CT: sens - 100%, spec - 100%, PPV - 100%, NPV - 100%, accuracy - 100% Detection of bone invasion PET/CT: sens - 100%, NPV - 100%. Performance for locoregional disease : PET/CT depicted the site of primary disease in all 8 cases referred for unknown primary detection, local infiltration to the vascular structures, soft tissue and bones and distant metastases in patients. (lung, mediastinum, liver). Conclusion: WB PET with CHCT has high diagnostic performance in the assessment of head and neck cancer and their loco regional spread, detection of necrosis and local infiltration of the tumors compared to PET with out contrast CT. Combined WB FDG-PET/CHCT has a very high NPV for residual/recurrent loco regional disease in post treatment evaluation is useful as a primary screening method for detecting second primary cancers and distant metastases and has a major incremental impact in the post treatment management of patients with HNC. When a WB PET/CT study is negative, additional clinical and radiological follow-up can be postponed, hence it is justifiable to perform WB FDG PET with CHCT in any stage of HNC patients.
Role of 18 F-FDG-PET/CT in carcinoma penis
JK Kiran Kumar, R Senthil, K Manohar, Raghav Kashyap, A Bhattacharya, Uttam Kumar Mete 1 , BR Mittal
Department of Nuclear Medicine and 1 PET and Urology, PGIMER, Chandigarh, India
Introduction: Carcinoma penis is a rare disease. Prognosis of patients with penile cancer mainly depends on presence of lymph nodal metastases. Though mandatory, inguinal lymphadenectomy is indicated in all cases, the procedure is associated with many complications like lymphedema, wound infection, etc. So imaging plays a crucial role in detecting lymph nodal involvement and thereby guiding the treatment. Objective: To determine the diagnostic value of 18 F-FDG PET/CT in initial staging and restaging of penile cancer with an emphasis on detection of lymph nodal involvement. Materials and Methods: Clinical and PET/CT data of 24 patients with penile cancer, who underwent 18 F-FDG PET/CT as a part of initial staging or restaging were retrospectively analyzed. All patients underwent 18 F-FDG PET/CT according to standard protocol. I.V. contrast was used. The reference standard was based on histopathology findings of biopsy/surgery, clinical and/or imaging follow up. Results: Twenty four patients (mean age: 54.2 yrs, range: 33 to 75 yrs) referred for carcinoma penis staging were included in the analysis. Ten cases were referred for initial staging and 14 cases were referred for restaging after initial treatment with curative intent. Out of 14 cases referred for restaging, six patients had undergone partial penectomy, two had undergone circumcision, two patients had undergone partial penectomy and bilateral inguinal lymphadenectomy, two cases had received chemotherapy, one case had received radiotherapy and one case had undergone partial penectomy and radiotherapy. Average time from surgery to PET scan was 3 months (range: 1 to 12 months). Out of 10 patients referred for initial staging, 18 F-FDG uptake was noted in all the primary tumors. Lymph nodal metastases were noted in 8 patients which were confirmed by surgery in 7 patients; one patient died due to haemorrhage by lymph nodal invasion into femoral artery confirming metastases. Two patients with no evidence of lymph nodal metastases on PET/CT underwent penectomy and were disease free at 6 months follow up. Out of 14 patients referred for restaging six cases were normal on the PET/CT scan and six patients showed lymph nodal residual disease, one patient had multiple distant metastases and one patient had only penile residual disease. All 6 patients with negative PET/CT study were free of disease on clinical follow up (mean follow up period of 6 months). All the six patients with positive PET/CT study for lymph nodal residual disease underwent surgery which was confirmed histopathologically. One patient with distant metastases died during follow up. One patient with suspicion of residual disease in penile stump was proven to false positive as patient remained free of disease during follow up without any intervention. Conclusion: 18 F-FDG PET/CT appears to be useful in detecting lymph nodal metastases during initial staging and restaging. This imaging modality can be of great help in detecting disease burdened hence further management.
Functional neuroimaging with 18 F-Flurodeoxyglucose (FDG) PET in amnestic mild cognitive impairment
Madhavi Tripathi, Manjari Tripathi 1 , Abhinav Jaimini, Maria M D'Souza, Sanjiv Saw, Romana Seher, Parul Gupta, Sahana Vishlavath, Rajnish Sharma, Anupam Mondal, RP Tripathi
Division of PET Imaging, INMAS, Timarpur, Delhi, 1 Department of Neurology, AIIMS, New Delhi, India
Introduction: People with amnestic mild cognitive impairment (aMCI) are at a higher risk of developing Alzheimers dementia (AD) than their cognitively normal peers. Decreased glucose metabolism with FDG is a sensitive marker for AD related pathological changes in the brain. The risk of developing AD is higher in patients with aMCI who have a pattern of AD related glucose metabolic changes on FDG-PET than those who do not have these changes. Objective: We evaluated the utility of visual and 'SPM-supported reading' of the FDG-PET scans of patients clinically classified as aMCI for identification of pre-dementia patterns and for prediction of their progression to AD. Patients and Methods: A total of 35 patients diagnosed as aMCI (MMSE score ≥25) by an experienced neurologist at the dementia clinic in AIIMS were referred to our centre for a resting FDG-PET study. All patients had a detailed neurological, neuropsychological and MRI evaluation prior to referral. Mean age of patients was 67.9 + 8.7 (SD) years, M:F=26:9. Patients were asked to fast for atleast 4 hours prior to the study and stop all medications on the day of test. 185-296 MBq of 18 F-FDG was injected intravenously and patient was rested in a dimly lit room with eyes open. After 60 minutes, a single bed 3D PET scan was acquired for 20 minutes on a STE16 camera (GE). Data was reconstructed using 3DVUE algorithm and viewed for visual analysis on a Xeleris workstation (GE) using Volumetrix protocol. 20 healthy age-matched controls were included in the study for SPM5 (http://www.fil.ion.ucl.ac.uk/spm/) analysis. Single case SPM5 analysis was done for each case for which images were normalized and smoothed followed by two-sample 't' test which resulted in 't maps' representing voxels of significant hyper or hypometabolism (P <.05) which were overlayed onto T1MRI template provided in SPM5 software thus creating canonical maps for each patient. Results: On visual analysis, 7 patients with aMCI reveled hypometabolism in AD related territories. 5 patients had hypometabolism in atleast one AD related territory and 3 patients had hypometabolism in other than AD territories. 20 patients did not show any significant hypometabolism on their FDG-PET scans. SPM5 analysis of these cases confirmed significant hypometabolism compared to a normal subgroup (P <.05) in the 7 cases with AD pattern, in 2 of the 5 cases with hypometabolism in a single region hypometabolism was demonstrated in atleast one more additional territory. 2 of the cases with no hypometabolism demonstrated involvement of atleast one AD related territory. Conclusion: Visual and SPM5 analysis thus identified AD hypometabolism pattern in 9 of the 35 cases (25%) and the need for a close follow-up in an additional 5 of the remaining cases. Analysis of FDG-PET images with these techniques can thus be extremely useful to identify AD related patterns in aMCI patients. (This work has been funded from an intramural grant from Director, INMAS, DRDO)
Role of 18 F-FDG PET/CT in restaging of patients with recurrent malignant melanoma
Manas Kumar Sahoo, Niraj Naswa, Varun Singh Dhull, Abhinav Singhal, Harmandeep Singh, Rakesh Kumar, Chandra Sekhar Bal, Arun Malhotra
Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India
Introduction: The incidence of malignant melanoma has increased in recent years. Patients with familial melanoma and a personal history of melanoma have a very high risk for the development of recurrence at other sites even after adequate treatment which demands a non invasive imaging modality for the early and accurate restaging of the recurrence of melanoma. We evaluated the role of 18 F-FDG PET/CT in restaging of patients with recurrent malignant melanoma.we found it to be an sensitive tool for restaging recurrent malignant melanoma. Objective: To determine the role of Flurodeoxy Glucose Positron Emission Tomography/Computed Tomography ( 18 F-FDG PET/CT) in restaging of patients with clinical suspicion of recurrent malignant melanoma. Materials and Methods: Twenty-eight patients (male:22; female-6) who had clinical suspicion of recurrent malignant melanoma underwent 18 F-FDG PET/CT scan for detection recurrent disease. All the patients were on fasting for at least 4-6 hours before imaging and blood glucose levels were below 140 mg/dl. All the patients were injected intravenous with 370 MBq of 18 F-FDG. PET-CT images were acquired 60 minutes after intravenous injection of radiotracer in a cranio-caudal fashion on a Seimens biograph2 PET/CT scanner. Results of the imaging were analysed by two experienced nuclear medicine physicians who were blinded to clinical details except initial diagnosis. Results: Of 28 patients, 18 patients were reported as having active recurrent disease while 10 patients showed no abnormal tracer uptake. To verify these findings, histopathology/follow-up imaging/clinical lookup were established as the gold standard. Of the 18 patients with positive scans, 15 were established as true positive while 3 patients had false positive PET-CT scans. Among the 10 negative PET-CT scans, 8 were defined as true negative and 2 false negative. The calculated sensitivity, specificity, positive and negative predictive values are found to be 88%, 73%, 83% and 80%, respectively for lesion detection of recurrent disease. The accuracy of the study was found to be 82%. Conclusion: 18 F-FDG PET/CT promises to be an important non-invasive diagnostic imaging modality in restaging patients with malignant melanoma suspected of having recurrence.
Role of 18 F-FDG PET-CT in detection of primary tumors in patients with cervical/extra cervical metastases of unknown origin
Ramya Soundararajan, Niraj Naswa, Aftab Hasan Nazar, Rakesh Kumar, Chandrasekhar Bal, Guru Bandopadhyaya, Arun Malhotra
Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India
Introduction: Carcinoma of unknown primary (CUP) is a heterogeneous group of histologically proven metastatic malignancies for which the primary tumor could not be detected despite thorough diagnostic evaluation. CUP accounts for 2.3-4.2% of cancer in both sexes and follows an aggressive behavior with a median survival of less than 1 year. Identification of a primary tumor has an impact on therapy and life expectancy and it is often detected only in 10-35% of all cases by conventional imaging modalities. Hence there is clearly a need of whole body, non invasive imaging modality with a high diagnostic yield. Objective: To evaluate the role of 18 F-FDG PET-CT in detection of primary tumors in patients presenting with cervical/extra cervical metastases of unknown origin. Materials and Methods: Fifty seven patients (38 males; 19 females; mean age (52.9%) with cytology/biopsy proven metastatic cervical/extra cervical sites and negative conventional imaging modalities(CT/Endoscopy/relevant tumor markers/MRI) were included in this retrospectively. Follow up PET-CT and/or histopathology defined the gold standard. Among 57 patients 29 patients presented with cervical lymph node metastases and remaining 28 patients presented with extra cervical sites of metastases [bone(13),liver(4),brain(4),axillary lymph nodes(4),inguinal lymph node(1),malignant ascites(1)and malignant pleural effusion(n=1)]. Patients were on fasting for at least 4-6 hours prior to imaging and blood glucose levels were <140 mg/dl. 370 MBq (10mCi) of F18-FDG was given I.V and images were acquired 60 minutes after injection on a Siemens biograph2 PET-CT scanner. Images were analyzed by two experienced nuclear medicine physicians, who were blinded to clinical details. Results: Among 57 patients 18 F-FDG PET-CT identified the primary site in 34 patients and for remaining 23 patients it was not localized. Among 34 patients with positive results 27 (47.3%) patients were true positives and remaining 7(12.2%) were false positives. 29 patients presented with cervical metastases among which the primary site was detected in 16 patients. 9(31%) of them were true positives and 7(24.1%) were false positives. Among 28 patients presented with extra cervical metastases primary site was identified in 18(64.2%) and remaining 10(35.7%) it was not identified. Hence the overall detection rate of primary site is 47.3%. Patients with cervical metastases the detection rate of primary is 31% and with extra cervical metastases the detection rate is 64.2%. Conclusion: 18 F-FDG PET-CT was found to be a useful diagnostic procedure and has high rate of detection of primary tumors in metastatic carcinoma of unknown origin. Detection rate of primary site in patients with cervical metastases is less compared to extra cervical metastasis due to high number of false positives.
Usefulness of whole body FDG18 PET-CT imaging in comprehensive oncologic management - Initial experience
Rinku Patel, Rasna Tiwari
Department of Nuclear Medicine, Gujarat Cancer and Research Institute, Ahmedabad, Gujarat, India
Introduction: The main application of positron emission tomography (PET) with Fluorine 18-deoxyglucose (FDG) is in the management of cancer patients due to the high correlation between cellular glucocydic activity and malignancy. Objective: To analyze the initial group of cases performed with dedicated PET scanner in GCRI for various clinical situations. Materials and Methods: We present the first 186 patients studied with a GE discovery PET / CT 600 using FDG for response evaluation after curative radio - chemotherapy, used as an additional diagnostic tool and for delineating target volume. Results: Most of the referrals from oncology (98%) and (2%) were studied due to neurological. symptoms. Lung lesions, gastro intestinal, breast carcinoma, melanoma, head and neck carcinoma and lymphoma corresponded to the most frequent diagnosis. Lung and lymphoma patients had clinical follow up. There was good concordance with anatomical images and histology in those cases with available data. In a significant number of patients new tumoral sites were detected. Conclusion: We confirm that in clinical practice, metabolic imaging with F18-FDG is helpful for cancer evaluation and management. With the initial use of FDG 18 PET-CT imaging, we realized that rate of distant metastasis is much higher which usually remain unnoticed because of conventional approach of investigation. PET-CT imaging has potential to improve the method of conventional IMRT planning.
18 F-FDG-PET/CT in the diagnosis and follow-up of patients with Takayasu arteritis
Sampath Santhosh, Gayana Manohar, Kashyap Raghav, Kuruva Manohar, Bhattacharya Anish, Bhagwant Rai Mittal, Aman Sharma 1 , Sanjay Jain 1
Department of Nuclear Medicine and PET and 1 Internal Medicine, PGIMER, Chandigarh, India
Introduction: Takayasu arteritis (TA) is a chronic, giant cell vasculitis of unknown aetiology. Traditional approach in the diagnosis and monitoring of response to immunosuppressive therapy is mainly based on the characteristic angiographic, clinical and laboratory findings. Objective: To evaluate the role of FDG-PET/CT in the diagnosis and follow-up (FU) of patients with TA. Materials and Methods: Retrospective analysis of FDG-PET/CT studies in patients referred for the evaluation of disease activity of TA was done. 15 patients underwent baseline PET/CT, and 3/15 patients underwent a total of four follow-up studies while on immunosuppression. Two nuclear physicians visually assessed the degree of 18 F-FDG uptake in the walls of the aorta, its major branches and the pulmonary artery using a 4-point scale from grade 0 to III as described by Meller et al. FDG uptake greater than grade I in the thoracic aorta or greater than grade 0 in other areas were interpreted as active vasculitic lesions. Results: The study included six males and nine females, with an average age 30±15years. In the baseline study, a score of atleast 2+ (in atleast one of the eight vascular segments analysed) was noted in ten patients (67%). FDG PET/CT was negative for active vasculitis in five patients, suggesting burnt out disease. The mean SUV max of the lesions was 6.4±4.2. Three patients underwent FU scans after oral steroid treatment. FU analysis: (Patient 1) Persistent and worsening symptoms after 6 month of therapy. Though the visual grade remained at 3+, the SUV max of the lesions increased from 4.2 to 10.6; new appearance of FDG uptake in the pulmonary arteries was also noted. This correlated with clinical presence of relapse in the form of recurrence of carotidynia, fever and increased inflammatory markers. (Patient 2) clinically normal status after 12 months of therapy. Though the visual grade remained at 3+ in the abdominal aorta, diffuse uptake was replaced by a patchy pattern and the SUV max decreased from 6.2 to 3.7, suggesting response to treatment. However, there was complete absence of FDG uptake (grade 0) in the bilateral iliac and origin of superior mesenteric artery compared to grade 3+ in the baseline study.
Comparison of Visual and 'SPM-supported analysis' of FDG-PET images for the differential diagnosis of Parkinsonian syndromes
Madhavi Tripathi, Vijay Dhawan 1 , Shichun Peng 1 , Abhinav Jaimini, Suman Kushwaha 2 , Tarun Vijay 3 , Maria M D'Souza, Santosh Pandey, Dinesh, Pradeep Thapa, Sonia Mahajan, Rajnish Sharma, Anupam Mondal, RP Tripathi
Division of PET Imaging, INMAS, Timarpur, Delhi, India, 1 The Feinstein Institute for Medical Research, North-Shore LIJ, Manhasset, New-York, USA, 2 Department of Neurology, IHBAS, Delhi, 3 Department of Neurology, GB Pant Hospital, New Delhi, India
Introduction: A number of studies using PET imaging with 18 F-Fluorodeoxyglucose (FDG) have described characteristic patterns of glucose metabolism in patients with Parkinsonism that can be used to differentiate Idiopathic Parkinsons disease from atypical Parkinsonian syndromes like Multisystem atrophy (MSA) and progressive supranuclear palsy (PSP). Objective: In this study we compared the diagnostic accuracy of visual reading by a trained expert to that of 'SPM-supported analysis' of single case FDG-PET images for differential diagnosis of Parkinsonian syndromes. Materials and Methods: A total of 165 patients diagnosed with Parkinsonism by expert neurologists and referred to our centre for a FDG-PET study were included. 20 healthy control subjects were also included for analysis. All patients underwent a resting 3D FDG-PET study in single bed position on a STE16 scanner (GE). Images were reconstructed using 3DVUE algorithm. The plain PET images were read by a PET expert blinded to the clinical data and classified into typical PD, MSA or PSP. Each study was also analysed by SPM 5 (http://www.fil.ion.ucl.ac.uk/spm/) running in MATLAB(Mathwork Inc). The images were spatially normalized and smoothened followed by statistical analysis using a general linear model. Voxels showing increased or decreased metabolism in the patient compared to the control group, above statistical threshold of P <.05 were overlaid onto T1MRI template image provide by SPM software and the resulting canonical maps were saved in PDF format to be read by an interpreter blinded to the clinical diagnosis. Diagnostic criteria were based on that published in literature. Diagnostic accuracy of visual interpretation was compared to that of 'SPM-supported reading' using the clinical diagnosis at the end of one year follow up as the gold standard. 31 patients with inadequate follow up or in whom the clinical diagnosis could not be ascertained at the end of follow-up were excluded from the study. Results: Visual reading was concordant with the clinical diagnosis in 90.2% of all patients. This concordance was 97% for PD, 80% for MSA and 76% for PSP. Sensitivity of visual analysis for PD was 96% while specificity was 94%. 'SPM-supported reading' was concordant with the clinical diagnosis in 84.3% of all patients. This concordance was 83% for PD, 75% for MSA and 93% for PSP. Sensitivity and specificity of this method for PD was 83% and 95% respectively. Conclusion: The results of visual classification of Parkinsonian syndromes was superior to that of 'SPM-supported reading' especially for PD and MSA. Early differential diagnosis of Parkinsonsonism is needed for prognostication of patients, for optimization of therapy and for correct inclusion into clinical trials. Visual and SPM- supported reading can be used together for the differential diagnosis of patients with Parkinsonism at an early stage when clinical diagnosis may be ambiguous. (This work has been supported from a grant from Indo-US Science and Technology Forum)
Role of high 18-F-Fluorodeoxyglucose uptake values correlation with histopathological factors in primary breast cancer
Mudalsha Ravina, MJ Jacob, Sougat Ray 1 , MS Chauhan, AG Pandit, Charu Jora, Anurag Jain
Department of Nuclear Medicine, Army Hospital (Research and Referral), Delhi, 1 Community Medicine (Armed forces medical college) Pune, India
Introduction: 18-F FDG uptake is an independent prognostic factor for relapse-free survival and histological grade. High FDG uptake can be used as a potential tool to select patients for aggressive chemotherapy and prognosticate the patients accordingly. Aim: The aim of the study was to determine a correlation between the 18-F FDG uptake values with histopathological factors in primary breast cancer. Materials and Methods: In our prospective study 72 patients (71 females and 1 male) were included. All patients underwent a pretreatment 18 F-FDG WBPET/CT. Standardized uptake values were compared with various histopathologicalfeatures. Analysis was carried out using SPSS Ver 10. Results: 'T' staging had significantly (P <0.05) positive (0.32) correlationwith SUV (max) values Median SUV max values of high grade tumors were 10.6 vs. 5.4 of low grade tumors. The SUV in the ER positive patients (6.01±4.16) was significantly less than in the ER negative patients (9.98±7.21, P0 = 0.005). Triple negative breast cancers had higher FDG uptake. Lesions with estrogen receptor (-ve) and HER/2-neu receptor (+ve) had higher uptake as compared to ER (+ve) and HER/2-neu (-ve). Conclusion: High uptake of 18 F-FDG can be predictive of poor prognosis(high grade, hormone receptor negativity, triple negativity) in patients with primary breast cancer. 18 F-FDG PET/CT could be a useful tool to pre-therapeutically predict biological characteristics and baseline risk of breast cancer.
Predictive value of FDG PET/CT scan in patients of lung cancer for detection of extrathoracic metastasis
SanjIv Saw, Madhavi Tripathi, Maria M D'Souza, Abhinav Jaimini, Rajnish Sharma, Romana Seher, Anil K Mishra 1 , Anupam Mondal
Division of PET Imaging, Molecular Imaging Research Center, INMAS, 10 Division of Cyclotron and Radiopharmaceutical Sciences, Molecular Imaging Research Center, INMAS, Delhi, India
Introduction : 0 Lung cancer 0 (LC) has an unfavourable prognosis especially when the disease is extensive at presentation. Accurate staging is therefore needed for treatment planning of these patients. In the present study the role of positron emission tomography/computed tomography 0 (PET/CT) in the detection of extrathoracic metastasis 0 in lung cancer is being evaluated. 0 Materials and Methods: All 52 of our patients with stage IIIA or lower of LC disease, a whole body 18 F-FDGPET/CT was performed. All patients were also subjected to general clinical evaluation, chest x-rays and chest contrast enhanced CT (CECT) and were confirmed by histopathology or magnetic resonance imaging or radiology. Results: Incidental extrathoracic 0 malignant lesions were found by 18 F-FDGPET/CT in 9 out of 52 patients(17.3%) no false positive lesions were found. As for the primary LC diagnosed by fine needle aspiration 0 cytology(FNAC). 18 F-FDGPET/CT diagnosed all 52 cases, CECT detected 0 46 cases and chest X-rays detected 28 cases. The diagnostic accuracy was 100%, 92%, 0 and 53.8% respectively. As for the 9 cases with extrathoracic metastasis diagnosed by 18 F-FDGPET/CT they were confirmed: by biopsy 6, by MRI 0 2, and by X-rays with or without biopsy 2. Conclusion : 0 18 F- FDGPET/CT had better diagnostic accuracy in diagnosing LC stage IIIA or lower, than CECT or chest X-rays. 0 Extrathoracic metastasis were high: 0 9/52 as diagnosed by 18 F- FDGPET/CT and standardised uptake value.