Stereotactic Radiation Therapy (SRT) for Brain Metastases of Multiple Primary Tumors: A Single Institution Retrospective Analysis.

To evaluate the efficiency and side effects of stereotactic radiation therapy (SRT) with or without other treatments for brain metastases (BM) from various primary tumors. This was a retrospective analysis of 161 patients with brain metastases treated with SRT. Clinical data, EGFR mutation status and survival data were collected. Follow-up data was analyzed until December 2018. Kaplan-Meier and Cox proportional hazards regression analyses were used for the survival analysis. The median overall survival (OS) was 19 months. No difference was observed in OS between SRT group and SRT + whole brain radiation therapy (WBRT) groups ( = 0.717). Statistically significant factors of better OS after univariable analysis were no extracranial metastases ( = 0.016), BED-SRT≥50Gy ( = 0.049), oligometastases (1-3 brain metastases) ( < 0.001), GPA score≥2.5 ( = 0.003), RPA class I ( = 0.026), NSCLC tumor type ( = 0.006), targeted therapy ( < 0.001) and controlled extracranial disease ( = 0.011). Multivariate analysis indicated that higher BED-SRT (≥50Gy, HR = 0.504, = 0.027), controlled extracranial disease (HR = 0.658, = 0.039) and targeted therapy (HR = 0.157, <0.001) were independent favorable predictors for OS. Besides that, we also find that the median overall survival (OS) was 22 months in NSCLC patients and controlled extracranial disease (HR = 0.512, = 0.012) and targeted therapy (HR = 0.168, < 0.001) were independent favorable predictors for OS. For patients with brain metastases, stable extracranial disease, higher BED-SRT (≥50Gy) and targeted therapy may predict a favorable prognosis.