Positron emission tomography with [F-18]fluoro-2-deoxy-d-glucose for diagnosis and staging of bile duct cancer

Malignant tumors with high glucose metabolic rates accumulate [18F]-fluorod eoxyglucose (FDG), a positron emitting tracer. The aim of this study was to evaluate FDG positron emission tomography (PET) for detection and staging of human cholangiocarcinoma (CC). Patients with adenocarcinoma of the bilia ry tree (n = 26), with benign lesions of the bile ducts (n = 8), and 20 con trol patients underwent FDG-PET (370 MBq [18F]-FDG, Siemens ECAT EXACT HR+) . In a blinded fashion, 4 independent experts evaluated the PET scans visua lly and semiquantitatively using the standardized uptake value and a tumor/ non-tumor ratio. All adenocarcinomas and benign lesions (sclerosing cholang itis, bile duct adenoma, Caroli's disease) were histologically proven and i maged by magnetic resonance imaging and endoscopic retrograde cholangioscop y. True-positive PET scans were obtained in 24 of 26 CC and false-negative scans in the other 2 (sensitivity 92.3%). The PET scan was true-negative in 18 of 20 controls and in all 8 benign biliary lesions (specificity 92.9%). Visual and semiquantitative evaluation using tumor/non-tumor ratios were e qually accurate (accuracy 92.6%) whereas evaluation by standardized uptake value revealed lower accuracy (P < .05). Regional or hepatoduodenal lymph n ode metastases were detected with PET in only 2 of 15 cases whereas distant metastases (peritoneal carcinomatosis, pulmonary metastases) were diagnose d in 7 of 10 cases. In conclusion, PET is highly sensitive and specific for the detection and localization of CC. It can be helpful for diagnosis of d istant metastases but is not suitable for detection of regional lymph node metastases.