A team from Germany studied patients with adenocarcinoma of the biliary tree (n = 26), with benign lesions of the bile ducts (n = 8), and 20 control patients who underwent FDG-PET
|PET scans for cholangiocarcinoma:|
In a blinded fashion, 4 independent experts evaluated the PET scans visually and semi-quantitatively using the standardized uptake value and a tumor/non-tumor ratio.
All adenocarcinomas and benign lesions (sclerosing cholangitis, bile duct adenoma, and Caroli's disease) were histologically proven and imaged by magnetic resonance imaging and endoscopic retrograde cholangioscopy.
The results revealed true-positive PET scans were obtained in 24 of 26 patients with CC and false-negative scans in the other 2 (sensitivity 92%). The PET scan was true-negative in 18 of 20 controls and in all 8 benign biliary lesions (specificity 93%).
Visual and semi-quantitative evaluation using tumor/non-tumor ratios were equally accurate (accuracy 93%), whereas evaluation by standardized uptake value revealed lower accuracy.
Regional or hepato-duodenal lymph node metastases were detected with PET in only 2 of 15 cases. Distant metastases (peritoneal carcinomatosis, pulmonary metastases) were diagnosed in 7 of 10 cases.
Dr Regine Kluge, of University Hospital of Leipzig, Germany, concluded, on behalf of the group, "PET is highly sensitive and specific for the detection and localization of CC.
"It can be helpful for diagnosis of distant metastases but is not suitable for detection of regional lymph node metastases."