Geographic and temporal variations in the utilization of stereotactic radiosurgery for treatment of non-small cell lung cancer brain metastases from 2010 to 2015: An analysis of the national cancer database

Purpose: This work describes trends in the utilization and survival benefit of stereotactic radiosurgery (SRS) with respect to geographic region of the United States and year of diagnosis among patients with NSCLC and synchronous brain metastases. Methods: Patients with NSCLC and synchronous brain metastases (2010–2015) were identified in the NCDB. Descriptive statistics were calculated across case SRS utilization and geographic region. Univariable and multivariable regression were performed to identify predictors of SRS treatment in the overall population and to estimate geographic region-specific models of SRS utilization and hazard of mortality over each year. Results: Among the 49,048 cases of NSCLC with synchronous brain metastases, 8310 were treated with SRS. Those in the Middle Atlantic had the greatest odds of SRS treatment, at 1.03 times those of patients in the East North Central (95% CI: 1.02–1.04, p < 0.001), whereas those living in New England had the lowest odds (OR: 0.96, 95% CI: 0.94–0.97, p < 0.001). Odds of SRS treatment and hazard of mortality decreased over time, with SBM patients diagnosed in the year 2015 having 1.12 times the odds of SRS (95% CI: 1.11–1.14, p < 0.001) and 0.82 times the hazard of mortality (0.79–0.85, p < 0.001) compared to those in 2010. Conclusion: Increased utilization of SRS was observed with decreased hazard of mortality over five diagnosis-years among NSCLC patients with synchronous brain metastases. These trends suggest the clinical burden of secondary cancers, particularly brain metastases, will increase in the years to come.