Prediction of Tumor Recurrence by 18F-FDG PET in Liver Transplantation for Hepatocellular Carcinoma

Although several prognostic factors are used to predict recurrence and to select adequate candidates for liver transplantation for hepatocellular carcinoma (HCC), these prognostic factors have some clinical limitations. The purpose of this study was to evaluate (18)F-FDG PET as a prognostic factor and to optimize its ability to predict tumor recurrence in liver transplantation for HCC. The study included a total of 59 HCC patients (45 men and 15 women; mean age +/- SD, 56 +/- 8 y) who underwent (18)F-FDG PET and subsequent orthotopic liver transplantation. All patients were followed up for more than 1 y (mean, 29 +/- 17 mo), and recurrence of tumor was monitored. Three PET parameters-maximal standardized uptake value (SUV(max)), ratio of tumor SUV(max) to normal-liver SUV(max) (T(SUVmax)/L(SUVmax)), and ratio of tumor SUV(max) to normal-liver mean SUV (T(SUVmax)/L(SUVmean))-were tested as prognostic factors and compared with conventional prognostic factors. Among the 3 parameters tested, T(SUVmax)/L(SUVmax) was the most significant in the prediction of tumor recurrence, with a cutoff value of 1.15. In a multivariate analysis of various prognostic factors including T(SUVmax)/L(SUVmax), serum alpha-fetoprotein, T stage, size of tumor, and vascular invasion of tumor, T(SUVmax)/L(SUVmax) was the most significant, and only vascular invasion of tumor had additional significance. According to T(SUVmax)/L(SUVmax), the 1-y recurrence-free survival rate above the cutoff was markedly different from the rate below the cutoff (97% vs. 57%, P < 0.001). In this study, (18)F-FDG PET was an independent and significant predictor of tumor recurrence. In liver transplantation for HCC, (18)F-FDG PET can provide effective information on the prognosis for tumor recurrence and the selection of adequate candidates for liver transplantation.