Usefulness of 18F‐fluorodeoxyglucose positron emission tomography in differential diagnosis and staging of cholangiocarcinomas

Abstract

(18)F-Fluoro-2-deoxy-d-glucose positron emission tomography ((18)FDG-PET) is promising for diagnosis and treatment of various malignancies. The aim of this study was to evaluate the clinical usefulness of (18)FDG-PET in differential diagnosis and staging of cholangiocarcinomas according to the intrahepatic, perihilar and common bile duct lesions and to compare with computerized tomography (CT) scan. From January 2000 to September 2003, 54 patients with suspected cholangiocarcinoma underwent abdominal CT scan and (18)FDG-PET within a 2-week period. The PET images were analyzed visually and semiquantitatively. The overall accuracy of (18)FDG-PET for discriminating malignant diseases of bile duct from benign conditions was slightly higher than that of CT scan (88.9% vs 81.5%). The sensitivity of (18)FDG-PET in perihilar cholangiocarcinoma was lower than the value of intrahepatic and common bile duct cancers (83.3% vs 91.3%, 90.9%); moreover, in cases of perihilar cancer, the sensitivity of (18)FDG-PET was lower than that of CT scans (83.3% vs 91.7%). (18)FDG-PET detected nine distant metastatic lesions not found by other imaging studies and excluded two patients who potentially had resectable condition in other imaging studies from unnecessary laparotomy. The clinical usefulness of (18)FDG-PET in differential diagnosis of bile duct cancers is related to the site of primary disease. Although it is a helpful method for differential diagnosis especially in cases of intrahepatic and common bile duct cancers, (18)FDG-PET can not provide confirmative clues in perihilar cholangiocarcinoma. (18)FDG-PET may hold promise in the detection of hidden distant metastasis and can play an additional role in the evaluation of resectability. (18)FDG-PET can be complementary to CT scan in diagnosing and staging of cholangiocarcinoma.