Arun Kumar Reddy Gorla

Comparative Effectiveness of Ultrasonography, 99mTc-Sestamibi, and 18F-Fluorocholine PET/CT in Detecting Parathyroid Adenomas in Patients With Primary Hyperparathyroidism

Purpose Accurate preoperative localization of parathyroid lesion(s) is crucial for successful surgical management of primary hyperparathyroidism (PHPT). This study was conducted to compare the effectiveness of ultrasonography (USG) of the neck, 99mTc-sestamibi (MIBI) imaging with or without SPECT/CT, and 18F-fluorocholine (FCH) PET/CT imaging in the preoperative localization of parathyroid lesions in patients with PHPT. Methods Fifty-four consecutive patients with PHPT were included in this prospective study who underwent preoperative localization of the parathyroid lesion(s) using 3 diagnostic modalities followed by surgery. The sensitivity, positive predictive value, and accuracy of the 3 imaging procedures to accurately detect abnormal parathyroid glands were determined using histopathology as criterion standard with postoperative biochemical response confirmation. Results 18F-fluorocholine PET/CT detected 52 of 54 patients and 52 of 56 lesions with histopathologically proven parathyroid adenomas on patient-based and lesion-based analysis, respectively. Preoperative USG, MIBI, and FCH PET/CT localized abnormal parathyroid gland(s) in 39 (72.2%), 43 (79.6%), and 54 (100%) patients, respectively. The sensitivity and positive predictive value were 69.3% and 87.1% for USG, 80.7% and 97.6% for MIBI, and 100% and 96.3% for FCH PET/CT. The accuracy was 62.9%, 79.6%, and 96.3% for USG, MIBI, and FCH PET/CT, respectively, in patient-wise analysis. In 6 patients with ectopic lesions, FCH PET/CT demonstrated higher sensitivity and accuracy than MIBI and USG (100% vs 66.6% and 16.7%, respectively). Conclusions Among the 3 imaging techniques tested simultaneously, FCH PET/CT was superior for accurate preoperative localization of parathyroid adenomas, especially for ectopic or small parathyroid lesions.

Substantial Increase in Myocardial FDG Uptake on Interim PET/CT May Be an Early Sign of Adriamycin-Induced Cardiotoxicity.

Cumulative cardiotoxicity is a well-established adverse effect of Adriamycin therapy. Although dose dependent, cardiotoxicity has been recently reported to occur even at lower doses than usually proposed. Conventional imaging detection and/or clinical manifestation of the deterioration in cardiac function occur late in the process; thus, it is desirable to have noninvasive markers to detect toxicity at an early stage. Several biochemical markers including troponin and atrial natriuretic peptide were explored for this purpose. The present case depicts that a significant increase in myocardial FDG uptake on posttherapy PET/CT can be a potential imaging biomarker of Adriamycin-induced cardiotoxicity.

Differential uptake of Tc-99m DMSA and Tc-99m EC in renal tubular disorders: Report of two cases and review of the literature

Tc-99m DMSA and Tc-99m EC studies are invaluable functional imaging modalities for renal structural and functional assessment. Normally, the relative renal function estimated by the two methods correlates well with each other. We here present two patients with renal tubular acidosis who showed impaired/altered DMSA uptake with normal EC renal dynamic study depicting the pitfall of DMSA imaging in tubular disorders. The two presented cases also depict distinct pattern of Tc-99m DMSA scintigraphic findings in patients with proximal and distal renal tubular acidosis, thus highlighting the factors affecting DMSA kinetics.

Utility of early dynamic and delayed post-diuretic 18F-FDG PET/CT SUVmax in predicting tumour grade and T-stage of urinary bladder carcinoma: results from a prospective single centre study

OBJECTIVE Accurate pre-treatment grading and staging of bladder cancer are vital for better therapeutic decision and prognosis. The aim of the present study was to evaluate the correlation between maximum standardized uptake value (SUVmax) calculated during early dynamic and post-diuretic fluorine-18 fludeoxyglucose (18F-FDG) positron emission tomography (PET)/CT studies with grade and pT-stage of bladder cancer. METHODS 39 patients with suspected/proven bladder carcinoma underwent 10-min early dynamic pelvic imaging and delayed post-diuretic whole-body FDG PET/CT imaging. SUVmax of the lesions derived from both studies was compared with grade and pT-stage. Relationship of SUVmax with grade and pT-stage was analyzed using independent sample t-test and analysis of variance. RESULTS SUVmax of the early dynamic imaging showing tumour perfusion was independent from the SUVmax of delayed imaging. High-grade tumours showed higher SUVmax than low-grade tumours in the early dynamic imaging (5.4 ± 1.4 vs 4.7 ± 1.6; p-value 0.144) with statistically significant higher value in Stage pT1 tumours (6.8 ± 0.8 vs 5.5 ± 1.2; p-value 0.04). Non-invasive pTa tumours had significantly less SUVmax than higher stage tumours during early dynamic imaging [F(4,29) = 6.860, p 0.001]. CONCLUSION Early dynamic imaging may have a role in predicting the grade and aggressiveness of the bladder tumours and thus can help in treatment planning and prognostication. Advances in knowledge: Dynamic PET/CT is a limitedly explored imaging technique. This prospective pilot study demonstrates the utility of this modality as a potential adjunct to standard FDG PET/CT imaging in predicting the grade and aggressiveness of the bladder tumours and thus can impact the patient management.

Unsuspected active ulcerative colitis in a patient with dermatomyositis: A rare association detected on 18F-FDG PET/CT during the search for an occult malignancy

Dermatomyositis is an inflammatory myopathy with the characteristic features of skin rash and myopathy. We here present a known case of dermatomyositis evaluated with 18F-FDG PET/CT for the presence of any occult malignancy. The scan was negative for the presence of any malignancy. However, it revealed multiple intensely FDG avid colonic strictures that were later proven on colonoscopic biopsy to be ulcerative colitis. Also, a well-known association of bilateral sacroilitis was simultaneously demonstrated on the scan. The present case demonstrates that 18F-FDG PET/CT imaging can serve as a one-stop shop imaging modality in dermatomyositis by facilitating detection of occult primary if any and by providing insight into other rare systemic associations.

68Ga-DOTATATE PET/CT in Primary Hepatic Neuroendocrine Tumor.

Primary neuroendocrine tumors of the liver are a diagnostic challenge. We present a rare case of primary hepatic neuroendocrine tumor in which Ga-DOTATATE PET/CT imaging played an important role in the diagnosis and follow-up.

Real-time intraprocedural 18F-FDG PET/CT-guided biopsy using automated robopsy arm (ARA) in the diagnostic evaluation of thoracic lesions with prior inconclusive biopsy results: initial experience from a tertiary health care centre

OBJECTIVE The aim of this study was to assess the feasibility and appraise the diagnostic utility of real time 18F-FDG PET/CT-guided biopsy under automated robopsy arm (ARA) guidance for the evaluation of thoracic lesions with prior inconclusive biopsy results. METHODS PET/CT-guided biopsy of thoracic lesions was performed in patients who had at least one previous inconclusive biopsy. A total of 25 patients (male:female-18 males, 7 females; age: range, 13-75; mean, 53.7) were included in this study. All these patients underwent percutaneous needle biopsies under real-time PET/CT guidance using ARA (ROBIO-EX, Perfint healthcare Pvt Ltd, Chennai, India) needle navigation technique. Histopathology and clinical follow-up results were reviewed for assessing the accuracy of procedures. RESULTS Adequate representative tissue sample could be retrieved in all the patients. No major procedure-related complications were encountered in any patient. Of the 25 procedures, 21 lesions were positive for malignancy and benign findings were observed in the other 4 lesions on histopathology. None of the patients required further biopsy in arriving at a final diagnosis. Overall diagnostic yield of the procedure was 100%. CONCLUSION Real time 18F-FDG PET/CT guidance for percutaneous biopsies of lung and mediastinal lesions is a feasible technique with potential utility in patients with previous inconclusive biopsy results. Advances in knowledge: 18F-FDG PET/CT guidance reduces the sampling errors by specifically targeting areas of viability and avoiding necrosis/atelectasis. A navigational tool like ARA is thought to help in accurately targeting these areas.

Adenosine stress induced left bundle branch block during technetium-99m tetrofosmin myocardial perfusion imaging

The occurrence of left bundle branch block (LBBB) in electrocardiogram during exercise testing is a relatively rare finding. The incidence of LBBB during exercise testing ranges from 0.5% to 1.1%. The mechanism of exercise-induced LBBB (EI-LBBB) is poorly understood, but ischemia is a proposed etiology. Stress myocardial perfusion imaging (MPI) can be useful in patients with EI-LBBB to rule out coronary artery disease. Adenosine vasodilator stress is the preferred mode of stress in patients with LBBB for performing stress-MPI. Here we present an interesting case of adenosine-induced LBBB during stress-MPI in a 67-year-old female patient with normal coronary angiography.

Potential Adjunctive Role of Radiosynovectomy in Primary Synovial Osteochondromatosis of the Knee: A Case Report

Primary synovial osteochondromatosis (PSOC) is a rare but clinically significant cause of morbidity especially in the male population. Surgery is the primary treatment of choice, but the recurrence rate is reported to be high. Moreover, the presence of widespread loose bodies makes it a cumbersome procedure. The complete removal of the disease is tough at times and results in early recurrence. Radiosynovectomy is an established technique for treating various joint arthropathies. The role of radiosynovectomy in case of PSOC has not yet been explored. This case report described the case of a young male with PSOC of the knee joint who was treated with radiosynovectomy for pain relief. The patient reported complete relief from the pain along with significant improvement in joint mobility. The post-therapy three-phase bone scan also validated the reduction in joint inflammation. The patient was taken for surgical removal of the redundant loose bodies after a significant improvement in the pain and reduction in inflammation. Post-therapy radiation fibrosis of the synovium also helped in the en bloc removal of the disease. The role of radiosynovectomy in PSOC needs to be further explored concerning its potential role as an adjuvant to surgical procedures.

18F-FDG PET/CT in Diagnostic and Prognostic Evaluation of Patients With Suspected Recurrence of Chondrosarcoma

Purpose The aim of the study was to analyze the diagnostic and prognostic utility of 18F-FDG PET/CT to predict the disease-specific survival (DSS) with FDG uptake and tumor grade in recurrent chondrosarcoma. Methods Retrospective analysis of FDG PET/CT findings in 31 previously treated patients (46 studies) with mean follow-up period of 40.7 ± 23.9 months (range, 3–77 months) from the date of first PET/CT study was done. Kaplan-Meier DSS analysis was made with respect to tumor grade, FDG uptake at the recurrent primary sites, and a combination of grade and FDG uptake as parameters. Results Recurrence (local and distant) was shown in 28 (60.8%) of 46 FDG PET/CT studies with sensitivity and specificity of 88.9% and 78.9%, respectively. The median SUVmax at the recurrent primary sites differed significantly (P = 0.008) among 3 tumor grade groups, with higher median SUVmax in higher grades. There was significant difference in median SUVmax among different grade groups except between grade II and grade III. Recurrent primary site SUVmax cutoff at 6.15 derived from the receiver operating characteristic curve yielded significant difference (P < 0.001) in mean DSS time. Significant difference in survival was noted between 3 different tumor grade groups (P = 0.016). The combination of SUVmax and grade improved the survival prediction than with grade alone. Conclusions In recurrent chondrosarcoma, the recurrent primary site FDG uptake and grade were found to be reliable prognostic factors with respect to DSS. PET/CT in recurrence setting has the potential to predict tumor grade and survival and may assist in clinical management.