The role of 18F-fluorodeoxyglucose positron emission tomography in the diagnosis, staging, and follow-up of cholangiocarcinoma

18F-Fluorodeoxyglucose positron emission tomography (18FDG-PET) is a new diagnostic technique for the diagnosis and staging of cholangiocarcinoma. For diagnosis of a primary cholangiocarcinoma, 18FDG-PET seems to be helpful to discriminate between malignant and benign lesions. However, the accuracy of 18FDG-PET seems to be dependent on the anatomic location, growth pattern, and pathologic characteristics of the lesion. It has been proved that the accuracy of 18FDG-PET is limited to detection of extrahepatic, infiltrating, and mucinous cholangiocarcinomas. Due to its lower sensitivity, 18FDG-PET provides complementary rather than confirmative information in the diagnosis of regional lymph node metastasis. In contrast, it has high accuracy in detecting unsuspected distant metastases. The role of 18FDG-PET in detecting cancer recurrence, monitoring treatment response, and predicting prognosis is still controversial.