To investigate the outcome and toxicities of patients with oligometastases from colorectal cancer treated by stereotactic body radiotherapy (SBRT) using risk-adapted dose prescription.

Patients with oligometastases from colorectal cancer who were referred for SBRT from February 2013 to March 2016 in Liuhe District People’s Hospital of Nanjing were treated with a total dose of 50-60 Gy in five fractions prescribed to the 60% isodose line of the maximum dose. Concurrent chemotherapy was not admitted during SBRT, while neoadjuvant/adjuvant chemotherapy was allowed. The clinical data, disease control, survival rate and adverse reactions were analyzed.

A total of sixty patients with 74 metastatic lesions were brought into the study, including 36 patients with single hepatic metastasis and 24 with single lung metastasis. Eight patients were treated with SBRT as initial treatments, and 52 patients were treated after recurrent oligometastases. The median follow-up duration was 27.5 months (ranging for 6.5-36.3 months) . The local control rates for the first and second year were 100.0% (95% CI=89.3%-100.0%) , the overall survival rate was 78.6% (95% CI=55.4%-91.9%) , and the disease-free survival rates were 61.7% (95% CI=38.1%-80.8%) and 55.4% (95% CI=31.7%-76.1%) , respectively. There was no serious adverse events above grade 3 during follow-up.

SBRT can provide an alternative to the surgical resection of oligometastases from colorectal cancer. However, more prospective studies are needed to validate its effectiveness.