Feasibility of Boosted Radioembolization for Hepatocellular Carcinoma Larger than 5 cm

Purpose: To address the feasibility of yttrium-90 (Y-90) glass microspheres administered at a boosted dose in large hepatocellular carcinomas (HCCs). Materials and Methods: From July 2016 to August 2017, 20 patients who underwent Y-90 radioembolization for treatment-na ve HCC met the following inclusion criteria: (i) nodular tumor, (ii) tumor size > 5 cm, (iii) Barcelona Clinic Liver Cancer stage A/B disease, (iv) target perfused tissue dose > 150 Gy, and (v) all tumors treated in 1 session of radioembolization. Follow-up radiologic findings and clinical outcomes were retrospectively reviewed until May 2018. Tumor response was determined per modified Response Evaluation Criteria In Solid Tumors. Results: Mean total radiation activity infused was 4.96 GBq +/- 1.82 (median, 4.88 GBq; range, 1.63-9.15 GBq). Mean target perfused tissue dose was 263.5 Gy +/- 95.2 (median, 241.6 Gy; range, 156.2-550:6 Gy). The mean number of vials used per treatment was 4.15 +/- 1.4 (median, 4; range, 2-7). Complete response rates were 25% at 1 month and 60% at 3 months. Complete response of the primary index tumor was achieved in 16 patients (80%) based on best tumor response. Local progression free survival and progression-free survival rates were 94.1% and 85.0% at 6 mo and 94.1% and 74.7% at 1 year, respectively. Four patients (20%) had symptomatic (n = 3) or asymptomatic (n = 1) benign biliary strictures. Conclusions: Radioembolization with a boosted dose in patients with large HCCs may show favorable tumor response, but with considerable biliary complications.