Efficacy, toxicities, and prognostic factors of stereotactic body radiotherapy for unresectable liver metastases

Introduction: This study aims to determine the outcomes of stereotactic body radiotherapy (SBRT) for liver metastases in patients not eligible for surgery.Methods: This study included 31 consecutive patients with unresectable liver metastases who received SBRT between January 2012 and December 2017; 22 patients had primary colorectal cancer and nine patients had primary non-colorectal cancer.Treatments ranged from 24 Gy to 48 Gy in 3 to 6 fractions over 1 to 2 weeks.Survival, response rates, toxicities, clinical characteristics, and dosimetric parameters were evaluated.Multivariate analysis was performed to identify significant prognostic factors for survival.Results: Among these 31 patients, 65% had received at least one prior regimen of systemic therapy for metastatic disease, whereas 29% had received chemotherapy for disease progression or immediately after SBRT.The median follow-up interval was 18.9 months; actuarial in-field local control rates at 1, 2, and 3 years after SBRT were 94%, 55%, and 42%, respectively.The median survival duration was 32.9 months; 1-year, 2-year, and 3-year actuarial survival rates were 89.6%, 57.1%, and 46.2%, respectively.The median time to progression