Survival outcomes after stereotactic body radiotherapy for 79 Japanese patients with hepatocellular carcinoma

Stereotactic body radiotherapy (SBRT) is a relatively new treatment for liver tumor. Outcomes of SBRT for liver tumors unsuitable for ablation or surgical resection were evaluated. A total of 79 patients treated with SBRT for primary hepatocellular carcinoma (HCC) between 2004 and 2012 in six Japanese institutions were studied retrospectively. Patients treated with SBRT preceded by trans-arterial chemoembolization were eligible. Their median age was 73 years, 76% were males, and their Child-Pugh scores were Grades A (85%) and B (11%) before SBRT. The median biologically effective dose (α/β = 10 Gy) was 96.3 Gy. The median follow-up time was 21.0 months for surviving patients. The 2-year overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival were 53%, 40% and 76%, respectively. Sex and serum PIVKA-II values were significant predictive factors for OS. Hypovascular or hypervascular types of HCC, sex and clinical stage were significant predictive factors for PFS. The 2-year PFS was 66% in Stage I vs 18% in Stages II-III. Multivariate analysis indicated that clinical stage was the only significant predictive factor for PFS. No Grade 3 laboratory toxicities in the acute, sub-acute, and chronic phases were observed. PFS after SBRT for liver tumor was satisfactory, especially for Stage I HCC, even though these patients were unsuitable for resection and ablation. SBRT is safe and might be an alternative to resection and ablation.