The Value of F-18 FDG PET in Patients With Primary Sclerosing Cholangitis and Cholangiocarcinoma Using Visual and Semiquantitative Analysis

Aim: The aim of this study was to assess the value of 18F-fluorodeoxyglucose positron emission tomography (F-18 FDG PET) in patients with suspected cholangiocarcinoma (CC). Methods: Sixty-five patients with suspected CC were included in this retrospective study. All patients had whole-body FDG PET/CT imaging at a mean time of 100 minutes after administration of FDG injection. PET studies were analyzed using visual analysis and semiquantitative analysis. Semiquantitative analysis was performed using maximum standardized uptake value (SUVmax) and tumor-to-normal liver (T/N) ratio. Malignancy was defined using the following criteria: (1) Visual analysis; (2) SUVmax >3.9; (3) T/N >1.6. Analysis of variance test and receiver operating characteristic analysis were used in statistical analysis. P < 0.05 was considered significant. Results: Follow-up revealed 47 patients with CC. The average SUVmax in CC tumors was 8 +/- 2.9 versus 3 +/- 1 in benign lesions (P < 0.0001). The average T/N in malignant lesions was 3.5 +/- 1.8 versus 1.3 +/- 0.4 in benign lesions (P < 0.0001). Sensitivity, specificity, and accuracy for the 3 criteria were as follows: (1) 96%, 67%, and 88%; (2) 94%, 83%, and 91%; (3) 89%, 78%, and 86%. Conclusion: F-18 FDG PET semiquantitative analysis using SUVmax >3.9 as criterion for malignancy could improve the diagnostic accuracy in differentiating malignant from benign lesions in patients with suspected CC.