Abstract No. 550 Comparison of efficacy of primary Yttrium-90 radiation segmentectomy versus percutaneous microwave ablation in patients with ≤4-cm hepatocellular carcinoma

Abstract

Current guidelines including Barcelona Clinic Liver Cancer (BCLC) criteria recommend thermal ablation for patients with 3 or fewer, <3-cm hepatocellular carcinoma (HCC) who are not surgical candidates. The objective of this study was to compare the tumor response and overall survival (OS) in patients with solitary, small (<4 cm) HCC treated with primary percutaneous microwave ablation (MWA) vs. Yttrium-90 (Y90) radioembolization radiation segmentectomy (RS). From March 2014 to March 2017, 118 consecutive treatment naïve patients with solitary HCC ≤4 cm were included. Baseline characteristics including patient age, gender, MELD score, BCLC stage and Child-Pugh (CP) scores were compared between the two groups using t-test and chi-square. Tumor response at 3 months post therapy was evaluated using modified Response Evaluation Criteria in Solid Tumors (m-RECIST). Survival from initial treatment was calculated using Kaplan-Meier estimation. Statistical analysis was performed using SPSS v25 (IBM, Armonk, NY) with significance set at 0.05. Overall, 118 consecutive patients were included of whom 75 patients were treated with MWA and 43 patients were treated with Y90 RS. Five of 75 patients (6.7%) in the MWA group and 2 of 43 patients in the RS were lost to follow-up. Median follow-up for the entire cohort was 30.2 months. The MWA group had smaller lesions diameter compared (1.7 cm) vs. those with RS (2.7 cm, P = 0.001). The MWA group had more patients who were ≤65 years (53.9% of patients) vs. RS group (37.2%, P = 0.079). While the MWA group had larger proportion of higher CP score (30.7% of CP B for MWA vs. 11.6% of CP B RS, P = 0.05), the RS group had higher BCLC B stage (76.7%) vs. 60.0% for MWA (P = 0.01). The incidence of favorable tumor response (partial or complete response) was similar for the two groups; 85.8% for MWA vs. 87.8% for RS (P = 0.49). There was no difference in OS from first procedure in the MWA group (46.4 months) vs. RS (43.7 months; P = 0.907). Our data suggests Y90 RS is noninferior to percutaneous MWA in the management of HCC lesions ≤4 cm with similar medium-term OS outcomes.Tabled 1MWAY90RSImaging Response (mRESIST) Complete Response57(76.0%)32(74.4%) Partial Response3(2.67%)4(9.30%) Stable Disease4(5.33%)2(4.65%)P=0.487 Progression of Disease6(8.0%)3(6.98%)Overall Survival (months)95% Confidence Interval46.3843.68P=0.907(41.47-51.286)(36.72-50.64) Open table in a new tab