Significance of preoperative fluorodeoxyglucose-positron emission tomography in prediction of tumor recurrence after liver transplantation for hepatocellular carcinoma patients: a Japanese multicenter study

Background: In the present study, we conducted a multicenter nationwide survey to investigate the effects of preoperative fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) on the prediction of hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT). Methods: From 16 Japanese LT centers, data were collected on 182 recipients with HCC who underwent living donor liver transplantation (LDLT) between February 2005 and November 2013. PET-positive status was defined as increased uptake of FDG in the tumor compared to the surrounding non-tumor liver tissue. The median follow-up after LDLT was 54.5 months (range 1–125 months). Results: Postoperative HCC recurrence occurred in 23 patients. Multivariate analysis revealed that exceeding the Milan criteria (MC), alpha-fetoprotein (AFP) level ≥115 ng/ml, and PET-positive status were significant and independent risk factors for recurrence. In the over-MC group, a subgroup of patients with AFP level <115 ng/ml and PET-negative status (n = 22) had a significantly lower 5-year recurrence rate than the other patients (n = 27, 19% vs. 53%, P = 0.019). Conclusions: These results suggest that preoperative FDG-PET status offers additional information on HCC recurrence risk after LT. Over-MC patients with PET-negative status and lower AFP level may achieve successful outcome comparable to that of within-MC patients.