The Lipogenesis Pathway: Radiolabeled Choline

Radiolabeled choline is a PET/CT radiopharmaceutical useful in detecting tumors with high lipogenesis rate. Choline may be labeled with 11C or 18F and is currently used as PET/CT tracer in the management of prostate cancer patients. Its role is limited during the early stage of this disease, but several studies support usefulness of radiolabeled choline PET/CT in evaluating patients with biochemical relapse of prostate cancer, following radiotherapy or radical prostatectomy for curative intent. In particular, the detection rate of radiolabeled choline of distant lymph node ore bone metastases is strictly linked to PSA serum level at the time of the scan. Consequently, the diagnosis of tumor relapse in oligo-metastatic patients could help in choosing the best therapeutic approach in order to improve patient prognosis and quality of life. Other tumors present malignant behavior but cannot be evaluated with 18F-FDG PET/CT, due to low grade of expressed glucose metabolism: the potential role of radiolabeled choline PET/CT in the management of patients with bladder cancer and bronchiolo-alveolar or hepatocellular carcinoma is under study. The exact knowledge of the normal in vivo distribution of radiolabeled choline can help nuclear physicians in avoiding misdiagnoses, due to the abnormal tracer uptake occurring in several benign or malignant conditions. From these diagnostic pitfalls, several researchers proposed a feasible role of radiolabeled choline PET/CT in the management of patients with brain tumors or in the diagnosis of hyperparathyroidism.