FDG-positron emission tomography/computed tomography and standardized uptake value in the primary diagnosis and staging of hilar cholangiocarcinoma

Background: The diagnosis and staging of hilar cholangiocarcinoma (HCCA) remain challenging despite recent advances in imaging. Little is known about the use of positron emission tomography/computed tomography (PET/CT) in HCCA. Objectives: This study aimed to evaluate the additional value of FDG-PET/CT and standardized uptake value (SUV) in patients with highly suspected HCCA. Methods: Between February 2006 and August 2009, PET/CT was performed in 30 patients with highly suspected HCCA, all of whom were deemed resectable by conventional staging methods, including laparoscopy. The results of PET-CT and SUV were compared with intraoperative and histopathological findings. Results: The primary tumour was 18F-FDG-positive in 88% of patients. Sensitivity and specificity for the detection of regional lymph node metastases and distant metastases were 67% and 68%, and 33% and 96%, respectively. The median SUV in the primary tumour was significantly (P <0.05) higher in patients with (mean: 8.9) than without (mean: 6.1) distant metastases. The SUV in patients with benign disease (n = 4) showed a trend towards lower values than in patients with cholangiocarcinoma, although this was not significant. Conclusions: After conventional staging including diagnostic laparoscopy, the additional value of PET/CT is limited. This somewhat disappointing finding may reflect the fact that extensive staging studies were carried out prior to PET/CT. The SUV potentially predicts patients with distant metastases and may differentiate between HCCA and benign lesions that mimic malignancies