Composite criteria using clinical and FDG PET/CT factors for predicting recurrence of hepatocellular carcinoma after living donor liver transplantation

Objectives: Fluorodeoxyglucose (FDG) PET/CT is effective for predicting recurrence of hepatocellular carcinoma after liver transplantation. This study aimed to design composite criteria for predicting post-transplantation recurrence using clinical and FDG PET/CT factors. Methods: We retrospectively enrolled 239 patients who underwent living donor transplantation in two independent centers between 2005 and 2013. On PET, maximum tumor-to-background ratio (TBR_max) was measured. Significant predictors for recurrence were selected by logistic regression and survival analyses. With varying cutoff values for the selected factors, composite criteria were designed to maximize the predictive performance for recurrence, and tenfold cross-validation was performed. Predictive values were compared between the composite criteria and the conventional recipient selection criteria. Results: Tumor size, number, alpha-fetoprotein, and TBR_max were selected as significant predictors in both logistic regression and multivariate survival analyses. In combination of these factors, the highest diagnostic performance was sensitivity of 75.7% and specificity of 88.5% with cutoff values of tumor size < 6.0 cm, tumor number < 8, alpha-fetoprotein < 465 ng/mL, and TBR_max < 2.8. The composite criteria exhibited the highest performance for predicting recurrence and recurrence-free survival among the tested criteria including conventional ones. Conclusions: The composite criteria adding FDG PET findings to clinical factors are effective in selecting appropriate liver cancer patients who are candidates for liver transplantation. Key Points: • In patients with HCC, tumor uptake on FDG PET/CT, tumor size, number, and serum AFP level are recognized individual predictors for tumor recurrence after LT. • A composite criterion set, combining tumor size, number, serum AFP level, and maximum tumor-to-background ratio (TBR_max), predicts post-LT recurrence most effectively when compared with conventional criteria sets in selecting candidates for living donor LT.