Comparison of Combination Stereotactic Body Radiotherapy Plus High-Intensity Focused Ultrasound Ablation Versus Stereotactic Body Radiotherapy Alone for Massive Hepatocellular Carcinoma.

BACKGROUND Thermal high-intensity focused ultrasound ablation is a non-invasive treatment of massive hepatocellular carcinomas. In stereotactic body radiotherapy, ablative radiotherapy is administered to tumors in targeted, limited doses to minimize damage to nearby tissues. We evaluated the outcomes and survival of patients receiving stereotactic body radiotherapy (singular therapy) versus those receiving combination thermal high-intensity focused ultrasound ablation plus stereotactic body radiotherapy (combination therapy). MATERIAL AND METHODS We compared data of 160 patients with massive hepatocellular carcinomas (12.5-18 cm) who were treated with combination therapy to those treated with singular therapy between January 2009 and February 2016. RESULTS Eighty-four patients were treated with single therapy while 76 were treated with combination therapy. Comparison of short-term outcomes and long-term survival between the groups revealed no significant differences in adverse events. In the combination group, the proportions of patients with complete response, partial response, stable disease, and progressive disease were 52.6%, 21.1%, 21.1%, and 5.3%, respectively; in the single therapy group, the corresponding rates were 0%, 23.8%, 50%, and 26.2%, respectively (P<0.0001). The 1-year, 3-year, and 5-year survival rates in the combination group were 33%, 20%, and 13%, respectively, while those in the single therapy group were 21%, 14%, and 1%, respectively. These data indicated no differences in complications between the groups except for a significantly higher level of skin edema in the combination group (P=0.015). CONCLUSIONS Combination therapy is more effective than single therapy for the treatment of massive hepatocellular carcinomas, although rates of most complications appear to be similar.