Although fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) has been widely used as a powerful tool in clinical oncologic imaging, its application in urological malignancies is limited. Recently, choline PET/CT has been successfully used for prostate cancer restaging. Here, we report the utility of choline PET/CT for the detection and monitoring of metastatic disease in two cases of renal cell carcinoma (RCC). A 53-year-old woman and a 45-year-old woman underwent FDG and choline PET/CT for evaluation of metastatic lesions in lymph nodes and bone following left and right RCC, respectively, and choline PET/CT demonstrated significantly higher uptake when compared with FDGPET/CT in both cases. Choline PET/CT accurately reflected the remission and progression of diseases in their clinical course, indicating that choline PET/CT could be a useful imaging modality in metastatic RCC
