Evaluation of 18F-FDG PET-CT as a prognostic marker in advanced biliary tract cancer

BACKGROUNDAdvanced biliary tract cancers have a dismal prognosis. Treatment with gemcitabine plus cisplatin has resulted in a significant improvement in survival; however, early assessment of outcomes poses a challenge. OBJECTIVEWe carried out a prospective study to evaluate the prognostic role of fluorine-18 fluorodeoxyglucose (F-FDG) PET-CT scans in patients with advanced biliary tract cancer. PATIENTS AND METHODSPatients with advanced unresectable or metastatic biliary tract cancer starting first-line chemotherapy with gemcitabine plus cisplatin underwent F-FDG PET-CT studies at baseline and after two cycles of therapy. The total lesion glycolysis (TLG) measured at baseline as well as the variation in TLG between the two studies were analyzed as prognostic indicators of overall survival. The survival analyses were carried out using Kaplan–Meier curves and the comparison of survival curves was performed using the Breslow test. RESULTSOf the 42 patients included, 37 had the first F-FDG PET-CT and 27 had the second F-FDG PET-CT. Patients with lower TLG values at baseline or after two cycles of therapy presented a higher median survival than patients with higher baseline TLG values. Patients with a higher decrease in the TLG values between the two studies also had a higher median survival time. However, these results only trended for statistical significance (P values ranging between 0.05 and 0.16). CONCLUSIONLower baseline TLG measured by F-FDG PET-CT as well as a decrease in metabolic uptake after chemotherapy were associated with a trend toward longer median survival among patients with advanced biliary cancers.