Comparison between stereotactic radiosurgery and whole-brain radiotherapy for 10-20 brain metastases from non-small cell lung cancer.

The efficacy and safety of stereotactic radiosurgery (SRS) in comparison with whole brain radiotherapy (WBRT) for brain metastases (BMs) remains unclear. The present study retrospectively reviewed 44 patients who received SRS or WBRT as an initial treatment for 10-20 BMs from non-small cell lung cancer between 2009 and 2016. Of the patients, 24 (54.5%) were treated with SRS and 20 (45.5%) were treated with WBRT. Overall survival (OS), time to intracranial progression (TTIP), neurological survival (NS), and prognostic factors were examined. OS did not significantly differ between the two groups: 7.3 months in the SRS group vs. 7.2 months in the WBRT group (P=0.502). Median TTIP was significantly shorter in the SRS group than in the WBRT group (7.1 vs. 19.1 months, P=0.009). In contrast, there were no significant differences in NS between the two groups (14.5 months in the SRS group vs. 12.9 months in the WBRT group, P=0.346). Univariate and multivariate analysis revealed that the type of initial treatment for BMs (WBRT or SRS) was not a significant prognostic factor (hazard ratio=0.80, 95% confidence interval: 0.42-1.52, P=0.502). However, histology, performance status, subsequent molecular targeted drugs, subsequent chemotherapy and salvage treatment were independent prognostic factors. There were no significant differences in OS and NS between treatment with SRS and treatment with WBRT in patients with 10-20 BMs, although TTIP was improved with WBRT. As an upfront treatment for 10-20 BMs, SRS may delay WBRT and the adverse events associated with WBRT.