Long‐term outcome of stereotactic body radiotherapy for patients with small hepatocellular carcinoma

AIM: To evaluate the long-term outcome of stereotactic body radiotherapy in patients with small hepatocellular carcinoma who were ineligible for resection or ablation therapies. METHODS: A total of 65 patients with 74 hepatocellular carcinomas (median tumor size 16 mm) were enrolled in the present study. They were treated with the prescribed dose of 48 Gy in four fractions at the isocenter. We extended the observation period and analyzed long-term outcomes, including overall survival, progression-free survival, local control, and various prognostic factors, in these patients. RESULTS: The median follow-up period was 41 months for all patients and 62 months for surviving patients. The 3- and 5-year overall survival rates were 56.3% (95% confidence interval, 44.1-68.5%) and 41.4% (95% confidence interval, 28.7-54.1%), respectively. The 3- and 5-year progression-free survival rates were 25.4% (95% confidence interval, 14.0-36.8%) and 10.6% (95% confidence interval, 1.5-19.8%), respectively. The 3- and 5-year local control rates were both 100% (95% confidence interval 100%). Liver toxicities exceeding grade 3 were observed in 15 patients (23.1%). The proportion of patients who had grade ≥3 toxicities did not increase. Adverse effects (grade ≤2) presented as significant prognostic factors of overall survival, while TNM stage (T1N0M0) was a significant prognostic factor of progression-free survival after multivariate analysis. CONCLUSIONS: Stereotactic body radiotherapy was effective for patients with small hepatocellular carcinomas who were ineligible for resection or ablation therapies. The incidence of grade ≥3 adverse effects did not increase, even after longer follow-up times.