title: Role of 18F-FDG PET/CT Imaging in Intrahepatic Cholangiocarcinoma.
abstract: OBJECTIVE
  Although intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy after hepatocellular carcinoma, there are limited data available on PET/CT imaging in ICC. This retrospective study analyzed the role of PET/CT imaging in the evaluation of ICC.
  
  
  METHODS
  FDG PET/CT findings were reviewed in 65 patients with histologically confirmed ICC. PET/CT was evaluated based on visual interpretation and the semiquantitative index of SUVmax and tumor-to-normal liver tissue ratio (TNR), which were consequently further analyzed and correlated with tumor localization, differentiation, size, and serum levels of tumor markers. Forty-five cases also underwent abdominal MRI examinations.
  
  
  RESULTS
  Nineteen patients had hilar ICC, whereas 46 patients had peripheral ICC. Sixty cases of ICC showed elevated FDG uptake with an average SUVmax of 8.3 ± 4.7 and TNR of 3.1 ± 1.7. Five cases located in the hilum were false negative on PET/CT imaging. Compared with hilar ICC, SUVmax and TNR of peripheral ICC were significantly higher (P < 0.05). FDG accumulation correlated with the degree of ICC differentiation. SUVmax and TNR correlated with tumor size, whereas there was no correlation observed with serum levels of carbohydrate antigen 19-9. The sensitivity, specificity, and accuracy of PET/CT and MRI in the diagnosis of regional lymph node metastases were 70.0% versus 50%, 91.7% versus 83.3%, and 81.8% versus 68.2%, respectively. PET/CT upstaged 12.3% and downstaged 3.1% of cases and had no impact on patient management in the remaining 84.6% of cases.
  
  
  CONCLUSIONS
  Combination of FDG PET/CT and abdominal MRI might improve the diagnostic accuracy for ICC.
authors.affiliation: From the *Department of Nuclear Medicine, Zhongshan Hospital, Fudan University; †Nuclear Medicine Institute of Fudan University; and ‡Shanghai Institute of Medical Imaging, Shanghai, China; and §St Gallen Cantonal Hospital, St Gallen, Switzerland.
authors.forename: Lei
authors.initials: L
authors.lastname: Jiang
authors.forename: Hui
authors.initials: H
authors.lastname: Tan
authors.forename: Cedric M
authors.initials: CM
authors.lastname: Panje
authors.forename: Haojun
authors.initials: H
authors.lastname: Yu
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiu
authors.forename: Hongcheng
authors.initials: H
authors.lastname: Shi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000097:blood / Q000000981:diagnostic imaging* / Q000473:pathology; D001653:Bile Ducts, Intrahepatic; D014408:Biomarkers, Tumor / Q000097:blood; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging; D018281:Cholangiocarcinoma / Q000097:blood / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D018285:Klatskin Tumor; D008113:Liver Neoplasms / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography / Q000379:methods; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D014408:Biomarkers, Tumor; D019788:Fluorodeoxyglucose F18