Anish Bhattacharya

Radioisotope scintigraphy in the diagnosis of hepatic hydrothorax.

Background: Pleural effusion in cirrhotic patients (hepatic hydrothorax) may result from migration of ascitic fluid across defects in the diaphragm. Biochemical analysis of ascitic and pleural fluid provides only indirect information about the nature and origin of the effusion. The present study was performed in order to demonstrate the presence/absence of peritoneo–pleural communication by radioisotope imaging.

Comparison of 18F fluoride PET/CT and 99mTc-MDP bone scan in the detection of skeletal metastases in urinary bladder carcinoma.

Aim The aim of this study was to compare 18F-fluoride PET/CT and 99mTc-MDP bone scintigraphy in the detection of skeletal metastases in urinary bladder carcinoma. Patients and Methods In this prospective study, 48 patients with urinary bladder carcinoma (44 male and 4 female patients, aged 35–80 years) underwent 99mTc-MDP planar and SPECT/CT bone scan (BS) followed by 18F-fluoride PET/CT within 48 hours. Skeletal metastasis diagnosed on each of these techniques was compared against a final diagnosis based on contrast-enhanced CT, MRI, skeletal survey, clinical follow-up, and histological correlation. Results 18F-fluoride PET/CT identified bony metastases and changed the management in 17 of 48 patients (35%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 99mTc-MDP planar BS were 82.35%, 64.51%, 56%, 86.95%, and 70.83%; of 99mTc-MDP SPECT/CT were 88.23%, 74.19%, 65.21%, 92%, and 79.16%; and of 18F-fluoride PET/CT were 100%, 87.09%, 80.95%, 100%, and 91.66%, respectively. Fair agreement between 99mTc-MDP planar BS and 18F-fluoride PET/CT (&kgr; = 0.42) and excellent agreement between SPECT/CT and 18F-fluoride PET/CT (&kgr; = 0.74) were found. Conclusions 18F-fluoride PET/CT has higher sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in detecting bone metastases in urinary bladder carcinoma than conventional 99mTc-MDP planar BS. SPECT/CT improves all these parameters compared with planar BS and may serve as a cost-effective screening procedure for the detection of skeletal metastases in high-risk patients.

Neonatal cholestasis: differentiation of biliary atresia from neonatal hepatitis in a developing country.

Aim:  To study the accuracy of various clinical and investigational parameters to differentiate biliary atresia (BA) from neonatal hepatitis (NH).

Comparison of 18F-FDG and 68Ga DOTATATE PET/CT in localization of tumor causing oncogenic osteomalacia.

Background Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome, usually caused by small benign mesenchymal tumors. The localization of these tumors is challenging, however, essential for the management. We compared the utility of 18F-FDG PET/CT and 68Ga DOTATATE PET/CT to detect the site of primary tumor in patients with suspicion of TIO. Patients and Methods Retrospective analysis of 6 patients with hypophosphatemic osteomalacia and suspicion of TIO was performed. 68Ga DOTATATE PET/CT study was performed in all 6 patients to localize the tumor. 18F-FDG PET/CT was performed in 4 of 6 patients. 18F-FDG and 68Ga DOTATATE PET/CT studies were performed within 1 week of each other. Both studies were interpreted blindly without the knowledge of other imaging findings. Results All patients had symptoms of osteomalacia and hypophosphatemia. All except 1 patient had increased level of fibroblast growth factor 23. The lag time (symptoms to PET diagnosis) ranged from 1.5 to 22 years. In 4 patients, where both studies were performed, 18F-FDG and 68Ga DOTATATE PET/CT were able to localize the tumor in 2 and 3 patients. 68Ga DOTATATE PET/CT detected tumor in 5 (83.3%) of 6 patients. Conclusions 68Ga DOTATATE PET/CT performed better than 18F-FDG PET/CT and is useful in the detection of tumors causing oncogenic osteomalacia. Therefore, in clinically suspected cases of hypophosphatemic osteomalacia, 68Ga DOTATATE PET/CT may be performed as first-line imaging investigation to avoid delay in the treatment of this devastating but curable disease. However, further studies with large patient population are warranted to validate our data.

Role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in the characterization of pancreatic masses: Experience from tropics

Early detection and differentiation of malignant from benign pancreatic tumors is very essential as mass‐forming pancreatitis is a frequently encountered problem. Positron emission tomography (PET) has a role in establishing the diagnosis of pancreatic carcinoma when the conventional imaging modalities or biopsies are nondiagnostic. In this prospective study, the utility of fluorodeoxyglucose (FDG)‐PET/computed tomography (CT) in the characterization of mass‐forming lesions of the pancreas was reported.

Clinical utility of F-18 FDG PET/CT in recurrent breast carcinoma.

Purpose Although initial studies have shown the utility of fluorine-18 fluorodeoxyglucose (F-18 FDG) PET in the detection and restaging of recurrent breast carcinoma, scarce literature exists on F-18 FDG PET/computed tomography (CT). This retrospective study was carried out to evaluate the role of F-18-FDG PET/CT in recurrent breast carcinoma and its impact on management. Materials and methods Retrospective analysis of data of 111 patients who underwent F-18 FDG PET/CT and were suspected of having recurrent breast carcinoma was carried out. PET/CT imaging was carried out for distant metastases in histologically proven locoregional recurrence in 23 patients, clinically suspicious locoregional recurrence in nine patients, increasing tumour markers in two patients, suspicion of distant metastatic disease in 61 patients or as a part of surveillance in 16 patients. The final diagnosis of recurrence and stage of disease was made after histopathological analysis, correlative imaging and clinical or imaging follow-up of at least 6 months. Results The final diagnosis of recurrent breast carcinoma was made in 76 patients and no evidence of recurrence was found in the remaining 35 patients. Locoregional disease requiring local radiotherapy or surgery was diagnosed in 14 patients and distant metastatic disease was diagnosed in 62 patients. FDG PET/CT was true positive in 75 patients, false positive in six patients, true negative in 35 patients and false negative in one patient, with a sensitivity, specificity, positive predictive value and a negative predictive value of 98.7, 85.3, 92.5 and 97.2%, respectively. FDG PET/CT also accurately restaged 22/23 patients with proven locoregional recurrence with an accuracy of 95.45%. Of 53 patients suspected of having distant metastatic disease on other imaging modalities, true distant metastatic disease was diagnosed in 36 patients and FDG PET/CT identified true metastatic disease in 35/36 patients, accurately ruling out metastases in the remaining 17 patients, and was false negative in one patient. In addition to confirming distant metastatic disease, it revealed more metastatic sites in 22 patients. Overall, F-18 FDG PET/CT had a major impact on management in 41% of the 103 patients being analysed for a major change in treatment. Conclusion F-18 FDG PET/CT is a very sensitive and specific imaging tool in detecting and restaging recurrent breast carcinoma. It can be a very useful imaging tool for restaging locoregional recurrences, and as a one-stop shop imaging technique to confirm suspicious metastatic disease on conventional imaging and to define the total burden of disease.

Large Spontaneous Coronary Artery Dissections A Study of Three Cases, Literature Review, and Possible Therapeutic Strategies

Spontaneous coronary artery dissection is rare, but is now being increasingly recognized as a prominent cause of acute ischemic coronary events occurring usually in relatively young patients, predominantly females. The authors describe the clinical course of 3 patients (1 woman) in whom large spontaneous coronary artery dissections developed. All had diverse clinical presentations; 1 presenting with heart failure, the second with post-myocardial infarction angina, and the third with syncope. The second patient underwent coronary angioplasty with multiple overlapping stents while in the other two, it was the considered opinion to continue aggressive medical therapy. The 1-year follow-up was uneventful in all 3 patients. The risk factors ascertained in our patients were diabetes mellitus, smoking, and hypertension.

18F-FDG PET-CT in evaluation of postoperative colorectal cancer patients with rising CEA level.

IntroductionAccurate imaging of patients with possible recurrent colorectal cancer (CRC) is vital, as it is now clear that curative surgery is still possible for a proportion of patients with metastatic disease. Follow-up is usually performed with carcinoembryonic antigen (CEA) level, computerized tomography (CT) and other conventional imaging techniques, but in the last few years, functional imaging using integrated positron emission tomography and CT (PET/CT) is being used increasingly to identify recurrent disease. AimTo evaluate the usefulness of integrated PET/CT in the follow-up of postoperative CRC patients with rising CEA level. Materials and methodsSeventy-three histopathologically proven patients with postoperative CRC having undergone CT of chest and abdomen were subjected to PET/CT imaging. Whole-body PET/CT imaging (base of skull to mid thigh region) was performed in all patients. These patients were grouped into various categories depending on CEA level. ResultsOf the total 73 patients, 22 had CEA levels within normal limits (<3 ng/ml). Among the remaining 51 patients, CT showed recurrence in 23 (45%) patients, whereas PET/CT was positive in 36 (71%) patients. In group 1 (CEA 3–5 ng/ml), CT was positive in four of 13 (30%) patients and PET/CT was positive in seven of 13 (53%) patients, in group 2 (CEA 5–10 ng/ml) CT was positive in three of nine (33%) patients and PET/CT was positive in six of nine (67%) patients, in group 3 (CEA 10–20 ng/ml) CT was positive in five of 11 (45%) patients and PET/CT was positive in seven of 11(63%) patients, in group 4 (CEA 20–50 ng/ml) CT was positive in five of nine (55%) patients and PET/CT was positive in seven of nine (77%) patients and in group 5 (CEA >50 ng/ml) CT was positive in six of nine (67%) patients and PET/CT was positive in nine of nine (100%) patients. Among 23 patients in whom both CT and PET/CT were positive, PET/CT showed extra lesions in 17 (73%) patients and changed the management in 11 (47%) patients. PET was negative in four patients with positive findings on CT, thereby changing the management. Of the total of 51 patients, PET/CT changed the management in 28 (55%) patients. ConclusionThis study shows an overall detection rate of 71% for PET/CT compared with 55% for CT in postoperative CRC patients with increasing CEA. PET/CT changes the management in half of the patients, highlighting the superior role of fluorodeoxyglucose PET/CT scan over CT scan.

Can fluorodeoxyglucose positron emission tomography/computed tomography avoid negative iliac crest biopsies in evaluation of marrow involvement by lymphoma at time of initial staging?

Abstract The assessment of bone marrow involvement (BMI) is important for accurate prognostication and deciding the appropriate therapy in patients with lymphoma. Conventional bilateral iliac crest biopsies (ILBMBs) have many limitations. F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is a useful investigative tool for detecting BMI. F-18 FDG PET/CT data for 97 patients with either non-Hodgkin lymphoma (NHL) or Hodgkin lymphoma (HL) were analyzed. ILBMB was performed 7–10 days later. A final diagnosis of BMI was made in 38/97 patients on the basis of composite criteria derived from both FDG PET/CT and ILBMB results. ILBMB detected BMI in 29/38 patients, 2/5 patients with HL, 27/33 patients with NHL, 19/25 patients with aggressive NHL, and 8/8 patients with indolent NHL with a sensitivity of 76%, 40%, 82%, 76%, and 100%, respectively. FDG PET/CT was true positive for BMI in 5/5 patients with HL and 29/33 patients with NHL, comprising 25/25 patients with aggressive NHL and 4/8 patients with indolent NHL, with a sensitivity of 100%, 88%, 100%, and 50%, respectively. FDG PET/CT performed better than ILBMB in cases of HL and aggressive NHL, but its sensitivity was poor in cases of indolent lymphoma. In addition, FDG PET/CT had a very high negative predictive value approaching 100% in HL and aggressive NHL, which might help in avoiding negative ILBMBs.

Prognostic value of quantitative parameters derived on initial staging 18F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with high-grade non-Hodgkin's lymphoma.

ObjectivesThis study was carried out to evaluate the role of quantitative parameters in staging PET in predicting prognosis in patients with high-grade non-Hodgkin’s lymphoma (NHL). MethodsA total of 51 histopathologically proven high-grade NHL patients treated with conventional chemotherapy regimens were included in the study. Total lesion glycolysis (TLG) and functional volumes (FVs) were defined as per the PET Response Criteria in Solid Tumors (PERCIST) criteria. All patients were followed up for a minimum period of 1 year or until an event, whichever occurred earlier. ResultsOf the four semiquantitative parameters studied, SUVmax and SUVmean did not show a statistically significant correlation with progression-free survival or overall survival, whereas TLG and FV showed a weak but statistically significant negative correlation. Using the receiver operating characteristic curve analysis, optimal cut-offs were derived for FV and TLG to predict progression and death. Using the cut-off values of 416 cm3 and 3340 g for FV and TLG, respectively, a statistically significant difference in progression-free survival and overall survival was obtained in the groups with FV and TLG above and below the threshold. On multivariate analysis of all the conventional prognostic factors and TLG more than 3340 and FV more than 416 cm3, only age greater than 60 years (P=0.013) and FV more than 416 cm3 (P=0.012) were found to be independently associated with disease progression. ConclusionOur results indicate that FV and TLG in staging PET/CT could be useful indices in predicting outcomes in patients with high-grade NHL treated with standard first-line chemotherapy regimens.