Mortality after stereotactic radiosurgery for brain metastases and implications for optimal utilization

Objectives: Brain metastases are associated with cancer progression and poor outcomes. The use of stereotactic radiosurgery (SRS) to treat brain metastases has been increasing due to its potential to quickly treat metastatic disease while avoiding the morbidity associated with surgery or whole brain radiation therapy (WBRT). This study seeks to analyze practice patterns of the use of SRS for brain metastases, focusing on the endpoint of short-term mortality. Materials and Methods: This study used the National Cancer Database to observe cancer patients diagnosed with a non-Central Nervous System primary from 2010 to 2012 who presented at diagnosis with metastatic disease to the brain and received either WBRT or SRS. The primary endpoint was time to mortality determined by the Kaplan-Meier product-limit estimate of the failure function. Results: A total of 18,604 patients were included in the analysis from first day of treatment (16,219 patients received WBRT and 2385 received SRS). At 90 days, mortality was 39.3% for those who received WBRT and 20.0% for those who received SRS. For patients 70 and older who received SRS, mortality was 30.2% at 90 days. Conclusions: Analysis of short-term mortality after treatment for brain metastases by using the National Cancer Database provides a window into national treatment patterns and associated outcomes. Roughly 1 in 5 patients who receive SRS and roughly 1 in 3 patients 70 and older who receive SRS die within 90 days of treatment. These data suggest some degree of overutilization of SRS in some patient populations, most notably those patients over the age of 70.