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A 50-year-old woman was diagnosed with iron deficiency anemia on general medical examination. Further, contrast-enhanced abdominal CT and magnetic resonance imaging revealed a large hypervascular mass with internal degeneration and necrosis in the retroperitoneal space. She was referred to our hospital for further evaluation and treatment. Because the paraganglioma was most likely as the imaging diagnosis, 123I-MIBG scintigraphy was performed. It revealed the marked abnormal accumulation in the retroperitoneal lesion indicating the paraganglioma and no other abnormal accumulation was noted. Several plasma catecholamines and their urinary metabolites were normal. On the subsequent 18FFDG PET/CT, high FDG uptake was found in the retroperitoneal lesion (SUVmax=38). FDG uptake was also found in a small nodule at the base of the lower lobe of the right lung (SUVmax= 9.8). Contrast-enhanced imaging revealed a hypervascular nodule at the base of the right lung, suggesting pulmonary metastasis of a paraganglioma. The abdominal lesion and right lung nodule were excised, and retroperitoneal paraganglioma and pulmonary metastasis were diagnosed based on the pathology findings. In this case, 18F-FDG PET/CT was useful in the search for paraganglioma metastasis. We report a relationship between 123I-MIBG accumulation and 18F-FDG uptake in paraganglioma and review the relevant literature. [ABSTRACT FROM AUTHOR]

Purpose: To analyse different uptake patterns in I-MIBG scintigraphy/SPECT imaging and F-FDG PET in paediatric neuroblastoma patients. Methods: We compared 23 I-MIBG scintigraphy scans and 23 F-FDG PET scans (mean interval 10 days) in 19 patients with a suspected neuroblastic tumour (16 neuroblastoma, 1 ganglioneuroblastoma, 1 ganglioneuroma and 1 opsomyoclonus syndrome). SPECT images of the abdomen or other tumour-affected regions were available in all patients. Indications for F-FDG PET were a I-MIBG-negative tumour, a discrepancy in I-MIBG uptake compared to the morphological imaging or imaging results inconsistent with clinical findings. A lesion was found by I-MIBG scintigraphy and/or F-FDG PET and/or morphological imaging. Results: A total of 58 suspicious lesions (mean lesion diameter 3.8 cm) were evaluated and 18 were confirmed by histology and 40 by clinical follow-up. The sensitivities of I-MIBG scintigraphy and F-FDG PET were 50% and 78% and the specificities were 75% and 92%, respectively. False-positive results (three I-MIBG scintigraphy, one F-FDG PET) were due to physiological uptake or posttherapy changes. False-negative results (23 I-MIBG scintigraphy, 10 F-FDG PET) were due to low uptake and small lesion size. Combined I-MIBG scintigraphy/F-FDG PET imaging showed the highest sensitivity of 85%. In 34 lesions the I-MIBG scintigraphy and morphological imaging findings were discrepant. F-FDG PET correctly identified 32 of the discrepant findings. Two bone/bone marrow metastases were missed by F-FDG PET. Conclusion: I-MIBG scintigraphy and F-FDG PET showed noticeable differences in their uptake patterns. F-FDG PET was more sensitive and specific for the detection of neuroblastoma lesions. Our findings suggest that a F-FDG PET scan may be useful in the event of discrepant or inconclusive findings on I-MIBG scintigraphy/SPECT and morphological imaging. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the prevalence of cardiac autonomic neuropathy (CAN) in a cohort of patients with type 2 diabetes, truly asymptomatic for coronary artery disease (CAD), using heart rate variability (HRV) and 123I-metaiodobenzylguanidine (123I- mIBG) myocardial scintigraphy. The study group comprised 88 patients with type 2 diabetes prospectively recruited from an outpatient diabetes clinic. In all patients myocardial perfusion scintigraphy, CAN by HRV and 123I- mIBG myocardial scintigraphy were performed. Two or more abnormal tests were defined as CAN-positive (ECG-based CAN) and one or fewer as CAN-negative. CAN assessed by 123I- mIBG scintigraphy was defined as abnormal if the heart-to-mediastinum ratio was <1.8, the washout rate was >25%, or the total defect score was >13. The prevalence of CAN in patients asymptomatic for CAD with type 2 diabetes and normal myocardial perfusion assessed by HRV and 123I- mIBG scintigraphy was respectively, 27% and 58%. Furthermore, in almost half of patients with normal HRV, 123I- mIBG scintigraphy showed CAN. The current study revealed a high prevalence of CAN in patients with type 2 diabetes. Secondly, disagreement between HRV and 123I- mIBG scintigraphy for the assessment of CAN was observed. [ABSTRACT FROM AUTHOR]

Aim: The aim of the study was to evaluate the current role of 123I-MIBG scintigraphy in the detection and follow-up of patients with paragangliomas. Materials and Methods: 117 patients were referred for diagnostic 123I-MIBG scintigraphy based on a strong clinical suspicion, positive familial history and genetic testing, or for follow-up of paragangliomas.123I-MIBG images were analyzed and correlated with 111In-octreotide scintigraphy, CT or MRI results. Accuracy of the imaging method was calculated per patient and per tumor per site. Results: A total of 117 patients were referred for 123I-MIBG diagnostic imaging; 80 patients were diagnosed with paraganglioma; 66 patients had a single neuroendocrine tumor and 14 patients multiple tumors. The total number of all lesions in these patients was 172. 123I-MIBG scintigraphy demonstrated 65 lesions in 56 patients (overall sensitivity: 56.3%, specificity: 84%). Lesion-per-site analysis revealed that sensitivity and specificity significantly varied per tumor site (lowest sensitivity for the head and neck: 17.5% and lowest specificity for the abdomen: 87.5%). Hormones were elevated in 85 patients: 55 123I-MIBG tumors were positive and 35 tumors were negative. In 16 patients (13.7%) with a genetic burden and a single neuroendocrine tumor, 123I-MIBG whole-body imaging was successful at detecting a second tumor. In 2 patients (1.7%) with paragangliomas, 123I-MIBG unexpectedly detected metastases, so the restaging was properly done. Conclusion:123I-MIBG scintigraphy remains important in pheochromocytoma and functioning neuroendocrine tumors. The value of 123I-MIBG scintigraphy is high in familial syndromes with multiple neuroendocrine tumors at different sites, multifocal tumors, and relapsing and metastatic disease. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]