C-11 Choline and FDG PET,CT Imaging of Primary Cholangiocarcinoma, a Comparative Analysis

Objective (s): This study aimed to compare the diagnostic values of 11C-choline and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with cholangiocarcinoma (CCA). This prospective study was conducted on 10 patients (6 males and 4 females)، aged 42-69 years، suspected of having CCA based on CT or magnetic resonance imaging (MRI) results. 11C-choline and 18F-FDG PET/CT studies were performed in all patients over 1 week. PET/CT results were visually analyzed by 2 independent nuclear medicine physicians and quantitatively by calculating the tumor-to-background ratio (T/B). No 11C-choline PET/CT uptake was observed in primary extrahepatic or intrahepatic CCA cases. Intense 18F-FDG avidity was detected in the tumors of 8 patients (%80). Two patients، who were 18F-FDG negative، had primary extrahepatic CCA. Ki-67 measurements were positive in all patients (range; 14. 2%-39. 9%). The average T/B values of 11C choline and 18F-FDG were 0. 4±0. 2 and 2. 0±1. 0 in all cases of primary CCA، respectively; these values were significantly lower for 11C-choline (P 0. 005). Both FDG and 11C-choline PET/CT detected metastatic CCA foci in all 8 patients (two patients had no metastases). As the results suggested، primary CCA lesions showed a poor avidity for 11C-choline، whereas 18F-FDG PET/CT was of value for the detection of most primary CCA cases. In contrast to primary lesions، metastatic CCA lesions showed 11C-choline avidity.