Long-term safety and efficacy of stereotactic body radiation therapy for hepatic oligometastases

Abstract

Purpose: To evaluate long-term outcome and toxicity of stereotactic body radiation therapy (SBRT) for hepatic oligometastases from solid tumors.

Methods and materials: Eligible patients had 1 to 3 liver metastases, maximum sum diameter 6 cm, without extrahepatic progression. We treated 106 lesions in 81 patients; 67% with colorectal primaries. Median dose was 5400 cGy in 3 to 5 fractions.

Results: At median follow-up of 33 months (2.5-70 months), overall local control was 94% (95% confidence interval, not estimable); Kaplan-Meier estimated 96% at 1 year and 91% at 2, 3, and 4 years. Partial/complete response was observed in 69% of lesions with less than 3% progressing. Median survival time was 33.6 months (95% confidence interval, 29.1-38.4); Kaplan-Meier survival estimates at 1, 2, 3, and 4 years were 89.9%, 68.6%, 44.0%, and 28.0%, respectively. Grade 3 or greater liver toxicity was 4.9%.

Conclusion: SBRT is effective for selected patients with hepatic oligometastases with limited toxicities. A phase 3 trial comparing SBRT with "gold-standard" surgical resection is warranted.