Stereotactic body radiation therapy following transarterial chemoembolization for unresectable hepatocellular carcinoma

Background: Transarterial chemoembolization (TACE) is the standard for unresectable Barcelona Clinic Liver Cancer (BCLC) B hepatocellular carcinoma (HCC) patients but is not an ablative therapy. This study explores stereotactic body radiation therapy (SBRT) as an adjuvant or salvage to drug eluting bead (DEB)-TACE. Methods: A retrospective review identified patients receiving SBRT within 2 years following DEB-TACE to a target lesion. Primary outcome was objective response (OR) using modified response evaluation criteria in solid tumors (mRECIST). Other outcomes included local control (LC), out of field failures, and overall survival (OS). Results: One hundred and three patients were identified with median 2 DEB-TACEs prior to SBRT. Fifty-two patients had planned adjuvant SBRT after DEB-TACE and the remainder had salvage SBRT with no statistical differences between groups. Of 95 patients with follow-up imaging, 59 (62.1%) had a complete response and 25 (26.3%) had a partial response (PR). More patients achieved CR (79.6% vs. 43.5%) with planned TACE + SBRT than salvage (P=0.006). LC was 91% and 89% at 1 and 2 years, respectively. One-year survival for planned DEB-TACE SBRT was 70.8% vs. 61.5% for salvage (P=0.052). Conclusions: Combination TACE + SBRT achieves high OR and LC rates. Adjuvant TACE + SBRT might achieve superior outcomes than salvage. This strategy might be particularly effective as a bridge to transplant.