Myocardial Perfusion Scintigraphy in a Patient With Transposition of Great Arteries Post-Atrial Switch Surgery.

ABSTRACT: We report a case of a 33-year-old woman who underwent stress and rest myocardial perfusion scintigraphy (MPS) to exclude coronary artery disease. MPS images showed an apparent dextrocardia with a right-sided septal wall uptake. The electrocardiograph showed a right axis deviation with dominant R waves at leads aVR and V1. Upon retrieval of the patient's medical records, she had an underlying transposition of great arteries and underwent a Senning atrial switch surgery. Hence, the MPS images demonstrated a prominent right ventricular wall due to its function as the "systemic" ventricle with minimal uptake in the "pulmonary" left ventricle.

Value of Baseline Post-Transplant MAG3 Renal Scintigraphy in the Evaluation of Graft Function.

INTRODUCTION: Accurate assessment of renal graft function in the early post-transplant period is crucial, as it influences clinical management and graft prognostication. However, there are limitations in current available modalities. MAG3 scintigraphy could contribute vital information on graft function. OBJECTIVES: This study aimed to determine the predictive value of parameters derived from MAG3 performed within 72 hours post transplant in detecting graft function. Delayed graft function (DGF), which is defined as dialysis requirement within the first week post transplant, is chosen as a surrogate measure of graft function. METHODOLOGY: All renal transplant recipients who underwent MAG3 within 72 hours post transplant from 2017 to 2019 were enrolled. Three MAG3 parameters, renogram grade, tubular injury severity score, and R20:3, were evaluated. RESULTS: A total of 117 patients were enrolled. The overall incidence of DGF was 16.2% with a significantly higher incidence amongst cadaveric graft recipients (53.6%) compared with living graft recipients (4.5%). Renogram grade ≥2, tubular injury severity score ≥4, and R20:3 > 1.31 significantly predicted DGF, P < .05 with high area under the curve for R20:3 of 0.97. Grafts with parameters above the cutoffs also showed significantly worse GFR at 1- and 3-months post-transplant. On multivariate analysis, prolonged cold ischemia time was associated with a higher risk of DGF, odds ratio 1.005 (95% confidence interval 1.003-1.007), P < .05. CONCLUSION: Baseline MAG3 accurately depicts early graft function and was also predictive of GFR at 1- and 3- months post-transplant. These baseline MAG3 scans could be particularly useful amongst deceased donor graft recipients owing to the higher risk of poor graft function.

Giant Liver Hemangioma Mimicking a Hydronephrotic Kidney on 99mTc-DTPA Scintigraphy.

We report a case of a 56-year-old woman who underwent Tc-DTPA renal scintigraphy for the evaluation of a right pelviureteric junction calculi, which incidentally showed radiotracer uptake in a giant liver hemangioma. The initial scintigraphic images showed a large lobulated lesion with peripheral uptake of radiotracer at the right abdominal region, resembling a large hydronephrotic kidney. However, the pattern of progression of the radiotracer, coupled with the clinical history and available corresponding radiologic images, confirmed the uptake to be that of a giant liver hemangioma.

Impact of 68Ga-DOTA-Peptide PET/CT on the Management of Gastrointestinal Neuroendocrine Tumour (GI-NET): Malaysian National Referral Centre Experience.

PURPOSE: The National Cancer Institute is the only referral centre in Malaysia that provides 68Ga-DOTA-peptide imaging. The purpose of this study is to determine the impact of 68Ga-DOTA-peptide PET/CT on the management of gastrointestinal neuroendocrine tumours (GI-NET). MATERIALS AND METHODS: A cross-sectional study was performed to review the impact of 68Ga-DOTA-peptide (68Ga-DOTATATE or 68Ga-DOTATOC) PET/CT on patients with biopsy-proven GI-NET between January 2011 and December 2015. Suspected NET was excluded. Demographic data, tumoral characteristics, change of disease stage, pre-PET intended management and post-PET management were evaluated. RESULTS: Over a 5-year period, 82 studies of 68Ga-DOTA-peptide PET/CT were performed on 44 GI-NET patients. The most common primary site was the rectum (50.0%) followed by the small bowel, stomach and colon. Using WHO 2010 grading, 40.9% of patients had low-grade (G1) tumour, 22.7% intermediate (G2) and 4.5% high (G3). Of ten patients scheduled for pre-operative staging, 68Ga-DOTA-peptide PET/CT only led to therapeutic change in three patients. Furthermore, false-negative results of 68Ga-DOTA-peptide PET/CT were reported in one patient after surgical confirmation. However, therapeutic changes were seen in 20/36 patients (55.6%) scheduled for post-surgical restaging or assessment of somatostatin analogue (SSA) eligibility. When 68Ga-DOTA-peptide PET/CT was used for monitoring disease progress during systemic treatment (sandostatin, chemotherapy, everolimus and PRRT) in metastatic disease, impact on management modification was seen in 19/36 patients (52.8%), of which 84.2% had inter-modality change (switch to everolimus, chemotherapy or PRRT) and 15.8% had intra-modality change (increased SSA dosage). CONCLUSIONS: 68Ga-DOTA-peptide PET/CT has a significant impact on management decisions in GI-NET patients as it can provide additional information on occult metastasis/equivocal lesions and supply the clinician an opportunity to select patients for targeted therapy.

Role of Pre-therapeutic (18)F-FDG PET/CT in Guiding the Treatment Strategy and Predicting Prognosis in Patients with Esophageal Carcinoma.

OBJECTIVES: The present study aimed to evaluate the role of pre-therapeutic (18)fluorine-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG PET-CT) and maximum standardized uptake value (SUVmax) in guiding the treatment strategy and predicting the prognosis of esophageal carcinoma, using the survival data of the patients. METHODS: The present retrospective, cohort study was performed on 40 consecutive patients with esophageal carcinoma (confirmed by endoscopic biopsy), who underwent pre-operative (18)F-FDG PET-CT staging between January 2009 and June 2014. All the patients underwent contrast-enhanced CT and non-contrasted (18)F-FDG PET-CT evaluations. The patients were followed-up over 12 months to assess the changes in therapeutic strategies. Survival analysis was done considering the primary tumor SUVmax, using the Kaplan-Meier product-limit method. RESULTS: In a total of 40 patients, (18)F-FDG PET-CT scan led to changes in disease stage in 26 (65.0%) cases, with upstaging and downstaging reported in 10 (25.0%) and 16 (40.0%) patients, respectively. The management strategy changed from palliative to curative in 10 out of 24 patients and from curative to palliative in 7 out of 16 cases. Based on the (18)F-FDG PET-CT scan alone, the median survival of patients in the palliative group was 4.0 (95% CI 3.0-5.0) months, whereas the median survival in the curative group has not been reached, based on the 12-month follow-up. Selection of treatment strategy on the basis of (18)F-FDG PET/CT alone was significantly associated with the survival outcomes at nine months (P=0.03) and marginally significant at 12 months (P=0.03). On the basis of SUVmax, the relation between survival and SUVmax was not statistically significant. CONCLUSION: (18)F-FDG PET/CT scan had a significant impact on stage stratification and subsequently, selection of a stage-specific treatment approach and the overall survival outcome in patients with esophageal carcinoma. However, pre-treatment SUVmax failed to stablish its usefulness in the assessment of patient prognosis and survival outcome.