Radiation-induced Continuous False-positive 18F-MFBG Uptake in the Perirenal Space of a Pediatric Neuroblastoma Patient

An 18F-MFBG PET/CT scan was conducted to evaluate the therapeutic response following treatment with chemotherapy, surgery, and radiotherapy. This study demonstrated increased 18F-MFBG accumulation in the right perirenal space, accompanied by a cloud-like shadow on the corresponding CT images, which was within the radiation therapy field. The lesion remained positive on subsequent follow-up 18F-MFBG PET/CT imaging. This abnormal MFBG accumulation was within the radiation therapy field. Based on the clinical history, this persistent 18F-MFBG uptake was considered to be related to prior radiotherapy, and should be considered in the differential diagnosis.