18F-choline PET/CT pitfalls in image interpretation: An update on 300 examined patients with prostate cancer

Objectives: 18F-choline PET/CT is an important diagnostic tool in the management of patients with prostate cancer (PC). The aim of this study was to describe and discuss some abnormal sites of uptake that we observed, not due to PC recurrence. Patients and Methods: Three hundred patients were submitted to 18F-choline PET/CT for staging or restaging of PC. Whole-body PET/CT was acquired 40 minutes after the 18F-choline administration. Results: We found abnormal uptake of the tracer, not related to PC, in 48/300 patients (16%). Most of these findings were due to inflammatory processes. Furthermore, some malignant conditions, such as a case of colon cancer, a case of bladder carcinoma, and a multiple myeloma, were diagnosed. Mild uptake was also detected in some benign diseases, such as thymoma, adrenal adenoma, and sarcoidosis. Six patients showed focal brain uptake in correspondence to a meningioma. Conclusions: It is necessary for nuclear physicians, during clinical practice, to consider the possibility of 18F-choline uptake in some benign or malignant conditions for the intrinsic pharmacologic property of the tracer. An accurate medical investigation, correlative imaging with CT and/or MRI with contrast agents, laboratory data, and above all, histologic examination are often necessary for correct diagnosis.