|Year : 2011 | Volume
| Issue : 5 | Page : 50-52
|Date of Web Publication||9-Dec-2011|
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
. Skeletal System. Indian J Nucl Med 2011;26, Suppl S1:50-2
Comparison of Tc99m-Methylene diphosphonate planer and SPECT/CT bone scan and 180 F -0 Fluoride PET/CT bone scan in detection of skeletal metastases in patients with carcinoma urinary bladder
Dhritiman Chakraborty, Anish Bhattacharya, Bhagwant Rai Mittal, UK Mete 1
Departments of Nuclear Medicine, 1 Urology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
Aim: The aim of this study was to compare 18 F-fluoride PET/CT with Tc99m-MDP planer and SPECT/CT bone scan for detecting skeletal metastases in cases of carcinoma urinary bladder. Materials and Methods: In this prospective study 48 consecutive patients (four female and 44 male; age range, 35-80 years; median age, 60 years) of carcinoma urinary bladder Tc99m-MDP planer, SPECT/CT bone scan and 18 F-fluoride PET/CT bone scan were performed within 48 hrs. The total number of lesions and involved sites were also counted in both scans and compared statistically for significance. Results: In comparison with the gold standard (histological diagnosis/CT or MRI correlation/Imaging follow up) the sensitivity, speciﬁcity, positive predictive value, negative predictive value and accuracy of Tc99m-MDP planar BS were 82.35%, 64.51%, 56%, 86.95% and 70.83% respectively, of Tc99m-MDP SPECT/CT were 88.23%, 74.19%, 65.21%, 92% and 79.16% and of 18 F-fluoride PET/CT bone scan 100%, 87.09%, 80.95%, 100% and 91.66%. Fair agreement between Tc99m-MDP Planar BS and 18 F-Fluoride PET/CT bone scan (Kappa=0.42) and excellent agreement between SPECT/CT and 18 F-Fluoride PET/CT bone scan (Kappa=0.74) was found. Conclusion: 18 F-Fluoride PET/CT bone scan has higher sensitivity, specificity, PPV, NPV and accuracy in detecting bone metastases compared to conventional Tc99m-MDP Planar BS. SPECT/CT improves all these parameters compared to Planar BS. Considering the availability and cost of 18 F-Fluoride PET/CT BS, Tc99m-MDP Planar BS along with SPECT/CT may serve as better initial screening procedure compared to 18 F-Fluoride PET/CT bone scan for detection of bone metastases in high risk patients with cancer of urinary bladder.
Metabolic patterns of 18 F-FDG uptake in patients of spinal tuberculosis and their comparison with MR findings
Gaurav Malhotra, Prabodhan Potdar 1 , Kshitij Choudhary 1 , Ramesh Asopa
Radiation Medicine Centre, Bhabha Atomic Research Centre, TMC Annexe, Jerbai Wadia Road, Parel, Mumbai, 1 Department of Orthopedics, KEM Hospital, Parel, Mumbai, India
Introduction and Aim: 18 F-FDG PET imaging has been established as a useful modality in Oncologic imaging. However, the metabolic tracer 18 F-FDG is not specific for the tumors and potential role of PET imaging is being studied in evaluation of infectious and inflammatory disorders. Few studies have shown metabolic pattern of 18 F-FDG uptake in spinal tuberculosis. The aim of this pilot investigation was to study the patterns of 18 F-FDG uptake in patients of spinal tuberculosis before and at various time points after initiation of antitubercular treatment (AKT). In addition PET findings were compared to the MR findings in these patients. Materials and Methods: The study group comprised 10 females (age range: 19-60 yrs median age: 27 yrs) and 3 males (aged 33, 34 and 37 yrs) of proven spinal tuberculosis (dorsolumbar vertebrae) who underwent 18 F-FDG PET scan as per the standard institution protocol. 14 PET scans were performed in 13 patients, one patient having undergone both pretreatment and a follow up scan. SUV max values were calculated for the main spinal lesion in each patient and were then correlated with the duration of treatment. Results : Time periods in which these PET scans were done ranged from baseline (zero day) to 365 days. 2 baseline scans, 6 scans in period from 20 to 90 days and 6 scans in period from 150 to 365 days after initiation of AKT were done. Statistical analysis revealed an inverse correlation of SUVmax with the time period after initiation of AKT (correlation coefficient: -0.64). FDG PET detected additional lesions as compared to MR in 10 of 13 patients. Psoas abscesses in association with the spinal lesions were observed in 12 of 13 patients. 18 F-FDG PET showed a typical pattern of central photopenia with metabolic activity of rim varying inversely with the duration of treatment. In patients with bilateral psoas abscesses 18 F-FDG uptake revealed a pattern resembling a 'butterfly' what we have termed as 'butterfly sign'. Conclusion : Metabolic uptake of 18 F-FDG in patients of spinal tuberculosis correlates inversely with the duration of treatment. The functional information gained from PET can aid in management especially in patients in whom MR cannot distinguish between post treatment changes and viable disease. In addition PET scanning showed a distinct advantage over MR by detecting additional areas of active disease by whole body screening. A distinct 'butterfly sign' was seen in bilateral psoas abscesses and FDG uptake in the rim of these inversely correlated with the duration of treatment.
Diagnostic gain of SPECT-CT in skeletal scintigraphy in non-oncologic applications
Hasmukh Jain, Indirani M, Shelley S, Alok Pawaskar
Department of Nuclear Medicine, Apollo Hospitals, Chennai, India
Skeletal scintigraphy, although having high sensitivity, has low specificity in characterizing a lesion with abnormally increased Tc-99m MDP uptake. This can partly be overcome by doing a regional SPECT study of the indeterminate lesion on planar images. At times, even SPECT may be of not much use due to low resolution and hence poor lesion characterization. Under such circumstances, regional SPECT study alongwith low-dose non-diagnostic CT, may be carried out for accurate anatomical localization and at times characterization also.
In the case, regional SPECT-CT study showed significant diagnostic gain over planar whole body images as well as SPECT studies without CT correlation. Addition of CT to the SPECT study, for suspected abnormal skeletal lesions on planar scintigraphy, provided complimentary information in the form of accurate anatomical localization and lesion characterization. Combined SPECT-CT imaging using single machine and during the same imaging study proved advantageous to the patient as considerable time and expenditure was saved, to the referring Physician as the scintigraphic findings either closely matched the clinical diagnosis or was provided with a different diagnosis not consistent with the clinical suspicion and to the reporting nuclear medicine physician in providing confidence and accuracy to the final interpretation.
Hence, combined SPECT-CT study improves the specificity of skeletal scintigraphy, by reducing the uncertainties associated with planar imaging or of the low resolution SPECT study.
Tc99m-MDP hybrid SPECT-CT for diagnosis of skull base osteomyelitis: Comparison with planar bone scintigraphy, SPECT and CT
Krishan Kant Agarwal, Punit Sharma, Harmandeep Singh, Rakesh Kumar, Chandrasekhar Bal, Arun Malhotra
Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India
Objective: The objective of the present study was to evaluate the role of Tc99m Methylene diphosphonate (MDP) single photon emission tomography-computed tomography (SPECT-CT) and compare the same with planar bone scintigraphy (BS), SPECT and CT. Materials and Methods: This was a retrospective study. Data of 13 patients with known or suspected skull base osteomyelitis was retrospectively analysed. All of the patients underwent three phase planar BS, SPECT, CT and SPECT-CT of head and neck region. Planar BS and SPECT images were evaluated by an experienced nuclear medicine physician. CT images were evaluated by an experienced radiologist. SPECT-CT images were evaluated by the nuclear medicine physician and radiologist in consensus. Depending on the diagnostic confidence images were given a score of 1 to 5, with 1 being definitely osteomyelitis, 2 being probably osteomyelitis, 3 being equivocal, 4 being probably normal and 5 being definitely normal. Receiver operating characteristic curve (ROC) analysis was done and areas under the curves (AUC) were compared. For calculation of diagnostic values a score of ≤2 was taken as positive and score of ≥3 was taken as negative. Clinical/imaging follow up was taken as reference standard. Results: The mean age was 55.3±17.5 years. There were 7 females and 6 males. Seven patients were diabetic. Based on reference standard 11 patients had skull base osteomyelitis and 2 patients had no ostemyelitis. The AUC was highest for SPECT-CT (0.977; SE-0.077) followed by SPECT (0.909; SE-0.148), CT (0.886; SE-0.163) and planar BS (0.614; SE-0.234). However, no significant difference was found between them except for borderline significance between planar scintigraphy with SPECT-CT (P=0.071) and CT (P=0.072). The sensitivity, specificity and accuracy of planar BS were 45%, 50% and 46% respectively. The values for SPECT were 90%, 50% and 85%, for CT were 73%, 100% and 77%, and that for SPECT-CT were 100%, 50% and 92% respectively. Conclusion: Tc99m-MDP appears to be a useful modality for diagnosis for skull base osteomyelitis with very high diagnostic accuracy.
Indeterminate lesions on planar bone scintigraphy in lung cancer patients: SPECT, CT or SPECT-CT?
Punit Sharma, Harmandeep Singh, Rakesh Kumar, Chandrashekhar Bal, Pramod Kumar Julka 1 , Arun Malhtra
Department of Nuclear Medicine, 1 Department of Radiation Oncology, All India Institute of Medical Sciences, New Delhi, India
Objective: The objective of the present study was to compare the role of single photon emission computed tomography (SPECT), computed tomography (CT) and SPECT-CT of selected volume in lung cancer patients with indeterminate lesions on planar bone scintigraphy (BS). Materials and Methods: The data of 50 lung cancer patients (53±10.3 years; range-30 to 75; male/female-38/12) with 65 indeterminate lesions on planar BS (January 2010 to November 2010) was retrospectively evaluated. All of them underwent SPECT-CT of a selected volume. SPECT, CT and SPECT-CT images were independently evaluated by two experienced readers (experience in musculoskeletal imaging, including CT: 5 and 7 years) in separate sessions. A scoring scale of 1 to 5 was used, in which 1 is definitely metastatic, 2 is probably metastatic, 3 is indeterminate, 4 is probably benign, and 5 is definitely benign. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) was calculated for each modality, taking score≤2 as metastatic. With receiver operating characteristic (ROC) curve analysis, area under the curves (AUC) were calculated for each modality and compared. Clinical and imaging follow up and/or histopathology were taken as reference standard. Results: For both readers SPECT was inferior to CT (P =0.004 and P =0.022) and SPECT-CT (P =0.003and P =0.037). However, no significant difference was found between CT and SPECT-CT for reader 1(P =0.847) and reader 2 (P =0.592). The findings were similar for lytic as well as sclerotic lesions. Poor inter-observer agreement was seen for SPECT images (κ=0.426), while almost perfect agreement was seen for CT (κ=0.834) and SPECT-CT (κ=0.971). Conclusion: CT alone and SPECT-CT are better than SPECT for accurate characterisation of indeterminate lesions on planar BS in lung cancer patients. CT alone is non-inferior to SPECT-CT for this purpose and might be preferred because of shorter acquisition time and wider availability.
Added advantage of Tc99m-MDP bone SPECT and 18 F-Fluoride PET study compared to planar bone scan in difficult cases
Sarita Sahoo, Purushottam Kand, S Basu, R Asopa, MGR Rajan
Radiation Medicine Center, B. A. R. C., Tata Memorial Centre Annexe, Parel, Mumbai, India
Introduction: Tc99m MDP whole body (WB) planar Bone scan is a highly sensitive technique for the assessment of bone metastasis. In certain clinical situations it could be indeed challenging to characterize skeletal lesions on planar WB scintigraphy either due to its site or its nature. Consequently, further additional investigation may be advised using SPECT or 18 F NaF WB Bone PET scan to assist greater delineation of such lesions. Based on this premise we conducted our retrospective comparative analysis of 18 F NaF WB Bone PET scan vs. Tc99m MDP Bone scan in difficult cases. Objective : Retrospective comparative analysis of 18 FNaF bone PET and 99m MDP bone SPECT and planar scan in difficult cases. Materials and Methods : 34 patients with proven malignancy referred for Tc99m -MDP bone scan for evaluation of metastatic disease status to the skeletal system were included. The study patient population consisted of 19 females and 15 males (age group: 5-75 yrs). All patients had undergone WB planar Tc99m MDP Bone scan. Additionally these patients had undergone WB SPECT study and /or 18 F NaF WB PET scan for further characterization of suspicious / difficult lesions either due to its site or its nature, noted on the WB Bone scan. The results obtained from the WB Tc99m Bone scan, WB Tc99m MDP SPECT scan and 18 F NaF WB PET scan were subjected to a lesions analysis which included: (a) Documentation of additional lesions, seen on the 18 F NaF WB PET scan and Tc99m MBP WB SPECT scan, if any in comparison to WB planar Tc99m MDP bone scan. (b) Characterization of suspicious/difficult lesion either due to site or its nature noted on Tc99m-MDP WB Planar Bone scan. (c) Exploring the PET technology for any additional characterization parameters in the assessment of skeletal metastatic disease. Results: An increase of 73% in the number of lesions detected by 18 F NaF PET Bone scan (199 lesions) as compared to the Tc99m MDP Planar Bone scan (115 lesions) in a variety of malignancies with metastasis to the skeletal system in 25 patients was noted. A 58% increase in detection of lesions was noted in 10 patients with skeletal metastasis using whole body SPECT Tc99m MDP bone scan (60 lesions) over the 38 lesions detected by Tc99m MDP Planar whole body Bone scan. 3 patients with all the three investigations demonstrated an additional 8 lesions on Tc99m MDP WB SPECT Bone scan and additional 10 lesions on 18 F NaF PET WB Bone scan in comparison to the 7 lesions detected on the planar WB Tc99m MDP bone scan. Semi-quantitative analysis technique of SUV gm-ml demonstrated a mean range of 18-30 gm-ml in all the metastatic lesions. Conclusion: 18 F-NaF PET is superior to Tc99m-MDP planar scintigraphy or SPECT in detecting skeleton metastatic lesions from a wide range of cancers in terms of number and characterization of lesions irrespective of their site and nature and hence a very an effective diagnostic technique in the assessment of difficult cases.
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