National Trends in External-Beam Radiation Therapy for Brain Metastases from Lung, Breast, and Melanoma Cancers

Abstract

Abstract Objective: Radiation therapy (RT) in the form of stereotactic radiosurgery (SRS) or whole-brain radiation therapy (WBRT) is fundamental for managing brain metastasis (BM). We analyzed national trends in RT and BM patient survival between 2010 and 2019. Materials and Methods: The US National Cancer Database was queried for patients receiving RT for BMs who were originally diagnosed with primary non-small cell lung cancer (NSCLC), small cell lung cancer, breast cancer, and melanomas from 2010 to 2019. Patients were grouped by WBRT (5-15 fractions; 20-45 Gy) or SRS (1-5 fractions; 10-40 Gy) treatment. Univariate and multivariate logistic regression analyses identified factors associated with receiving SRS over WBRT. Differences in treatment trends were assessed with Kruskal-Wallis tests. Post-treatment survival was assessed using Kaplan-Meier analysis and a Cox proportional hazards model. Results: In total, 59,839 patients were included; 41,197 (68.8%) received WBRT and 18,642 (31.2%) received SRS. Patients who were more recently diagnosed, treated at facilities outside of the East Central regions, insured, diagnosed with NSCLC subtype or melanoma, and who received chemo-/immunotherapy had higher odds of being treated with SRS (all P < .005). SRS, a more recent primary diagnosis, conjunctive use of chemo/immunotherapy, and luminal A/B breast cancer histologies (all P < .01) correlated with increased survival. Conclusion: The use of SRS has increased with patient survival over the last decade. We hypothesize that in addition to SRS-reducing neurotoxicity, this increase is due to guideline relaxation, improved techniques, and increased accessibility. Increased patient survival also indicates a possible relationship between SRS usage and improved survival.