Overall survival and toxicity of hepatocellular carcinoma Barcelona Clinic Liver Cancer B patients receiving Y90 radioembolization: analysis of the radiation-emitting SIR-spheres in non-resectable liver tumor (RESiN) registry

Background: To evaluate overall survival (OS), progression-free survival (PFS) and toxicity after resin Yttrium-90 (Y-90) radioembolization in Barcelona Clinic Liver Cancer B (BCLC B) hepatocellular carcinoma (HCC) patients using the Bolondi subgroup classification. Methods: A total of 144 BCLC B patients were treated between 2015–2020. Patients were broken into 4 subgroups by tumor burden/liver function tests with 54, 59, 8 and 23 in subgroups 1, 2, 3 and 4. OS and PFS were calculated with Kaplan-Meier analysis with 95% confidence intervals. Toxicities were assessed using Common Terminology Criteria for Adverse Events (CTCAE) v5. Results: Prior resection and chemoembolization were performed in 19 (13%) and 34 (24%) of patients. There were no deaths within 30 days. Median OS and PFS for the cohort were 21.5 and 12.4 months. Median OS was not reached for subgroup 1 at a mean 28.8 months, and was 24.9, 11.0 and 14.6 months for subgroups 2–4 (χ²=19.8, P=0.0002). PFS by BCLC B subgroup was 13.8, 12.4, 4.5, and 6.6 months (χ²=16.8, P=0.0008). The most common Grade 3 or 4 toxicities were elevated bilirubin (n=16, 13.3%) and decreased albumin (n=15, 12.5%). Grade 3 or greater bilirubin (32% vs. 10%, P=0.03) and albumin (26% vs. 10%, P=0.03) toxicity were more common in the subgroup 4 patients. Conclusions: The Bolondi subgroup classification stratifies OS, PFS and development of toxicity in patients treated with resin Y-90 microspheres. OS in subgroup 1 approaches 2.5 years and Grade 3 or greater hepatic toxicity profile in subgroups 1–3 is low.