Open-label prospective study of safety and efficacy of glass-based Y-90 radioembolization for infiltrative HCC with PVT.

Abstract

276 Background: Safety and efficacy of Yttrium-90 (Y90) therapy for infiltrative unresectable hepatocellular carcinoma (HCC) with portal vein thrombosis (PVT) require further evaluation. Methods: A prospective single center, open-label, single arm safety and efficacy study recruited patients with unresectable (Barcelona Liver Cancer Stage C) infiltrative HCC with PVT. Safety was assessed according to Common Terminology Criteria for Adverse Events v.3.0 at 1 week and monthly thereafter for 6 months post therapy. Efficacy was assessed by overall survival (OS) as primary endpoint. Tumor response was assessed by dynamic contrast MRI according to Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST at 1, 3, and 6 months (secondary endpoint). To achieve 0.95 power (α=0.05) and predicting prolongation of mean OS by at least 50% over the best supportive care (4 months ± 2 months (SD)), the study was designed to recruit 30 patients. Survival analysis was performed using Kaplan-Meier estimation. Prognostic factors were tested using log-rank and univariate analysis. Results: Thirty (n=30) patients were enrolled and underwent Y90 therapy (median age 63). The median OS was 13 months (CI: 4.1-21.1 months). Six patients had transaminitis (70% grade 1, 30% grade 2) while 8 patients had biliary toxicity (50% grade 1, 10% grade 2, 40% grade 3). Grade 3 bilirubin toxicity occurred in the same 2 patients with grade 2 transaminase toxicity. Although all patients recovered from transient liver toxicities, grade ≥2 liver toxicity was found to be predictor of poor outcome with median OS of 3.6 months for patients with grade ≥2 toxicity vs. 13 months for those with grade 1 or no toxicity (p=0.004). Child-Pugh class B, INR ≥1.5, and grade ≥2 hepatobiliary toxicities were found to be poor prognostic factors by both log-rank and univariate analysis (p<0.05). Upon short-term imaging follow up (mean 34 days post Y90), 80% of patients were found to have complete (13%) or partial (67%) response according to targeted mRECIST criteria, with 93% stable disease according to targeted RECIST. Conclusions: In patients with unresectable infiltrative HCC and PVT, Y90 therapy is a viable and safe treatment option.