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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]