Stereotactic Body Radiotherapy for Pulmonary Oligometastasis from Colorectal Cancer

Background/aim: A retrospective study was conducted to evaluate the safety and efficacy of stereotactic body radiotherapy (SBRT) for pulmonary oligometastasis from colorectal cancer (CRC).

Patients and methods: Patients with pulmonary oligometastasis from CRC who were treated with SBRT between April 2010 and October 2018 were enrolled in this study. All patients underwent SBRT using Cyberknife® with a dose of 54-60 Gy in 3 fractions to 99% of the clinical target volume. The treatment efficacy was evaluated by the local control (LC) and overall survival (OS) rates. The toxicity was evaluated using the National Cancer Institute's Common Terminology Criteria for Adverse Events version 4.0.

Results: Twenty-six lesions in 20 patients were treated with SBRT. The median follow-up duration was 19 months (range=6-98 months). Local recurrence occurred in 6 of 26 lesions with a median follow-up of 12 months. The 2-year LC and OS rates were 65.8% and 88.6%, respectively. No patient developed ≥ grade 2 toxicity in the lung and other sites.

Conclusion: Although very high doses were delivered to the tumors with SBRT, the LC of pulmonary metastasis from CRC was not satisfactory when compared to that for stage I primary non-small cell lung cancer reported in the literature.