Gadoxetic acid-enhanced MRI as a predictor of recurrence of HCC after liver transplantation

OBJECTIVES: To investigate the value of preoperative gadoxetic acid-enhanced MRI for tumor staging and recurrence prediction of hepatocellular carcinoma (HCC) after primary liver transplantation (LT). METHODS: This multicenter retrospective study included 122 recipients who underwent living donor LT (LDLT) for untreated HCC and pre-transplant gadoxetic acid-enhanced MRI from January 2009 to December 2013. Disease-free survival (DFS) was evaluated. Milan criteria, tumor grade, and microvascular invasion (MVI) were analyzed on the pathological examination of the explanted liver. RESULTS: The 1-, 3-, 5-, and 7-year DFS rates were 93.3%, 90.7%, 88.9%, and 86.1%, respectively. In the multivariable analysis, independent predictors of HCC recurrence were "beyond the Milan criteria" (hazard ratio [HR], 3.54; 95% confidence interval [CI], 1.13-11.12; p = 0.030) and peritumoral hypointensity on hepatobiliary phase (HBP) (HR, 18.30; 95% CI, 4.33-77.34; p < 0.001). Pre-transplant MRI yielded a 90.2% accuracy to categorize the Milan criteria when compared with the explanted liver. Peritumoral hypointensity on HBP was significantly associated with a worse tumor grade (p = 0.010) and MVI (p < 0.001). The 5-year DFS rate in patients with "beyond the Milan criteria" but the absence of peritumoral hypointensity on HBP was not different from that in patients "within the Milan criteria" (92.2% vs. 92.9%, p = 0.438). CONCLUSIONS: Pre-transplant gadoxetic acid-enhanced MRI may assist in the HCC recurrence risk prediction. KEY POINTS: • Lesions beyond the Milan criteria and peritumoral hypointensity on hepatobiliary phase (HBP) were independent predictors of HCC recurrence. • Peritumoral hypointensity on HBP significantly associated with a worse tumor grade and microvascular invasion.restrictio