Clinical outcomes of stereotactic body radiation therapy for small hepatocellular carcinoma

Background and Aim: The purpose of this study was to investigate the long-term oncologic outcomes after stereotactic body radiation therapy (SBRT) for small hepatocellular carcinoma (HCC). Methods: A total of 290 patients with HCC were registered between March 2007 and July 2013. A dose of 10–15 Gy per fraction was given over three to four consecutive days, resulting in a total dose of 30–60 Gy. Overall and recurrence-free survivals were estimated from the date of the start of SBRT to the date of death, the last follow-up examination, or to the date of tumor recurrence. Results: The median follow-up period of all patients was 38.2 months, and the median tumor size was 1.7 cm. Overall survival (OS) rate at 5 years was 44.9%. Multivariate analyses revealed that age, Child–Pugh class, tumor size, and albumin levels were significant factors for OS. The 5-year local control rate was 91.3%. In multivariate analysis, tumor size and albumin were significantly associated with local tumor control. However, there was a negative correlation between total dose and tumor size in Pearson's correlation analysis (r = −0.111, P = 0.046). Conclusions: Stereotactic body radiation therapy was an excellent ablative treatment option for patients with small HCC. Tumor size was a significant factor for local tumor control after SBRT, although the total dose was negatively correlated with tumor size. Considering the low OS rates and the high local tumor control rates, the combined SBRT and systemic therapies may be beneficial for improving survival outcomes.