Disparities in the use of stereotactic radiosurgery for the treatment of lung cancer brain metastases: a SEER-Medicare study

Stereotactic radiosurgery (SRS) is a costly procedure used to irradiate disease tissue while sparing healthy tissue, ideally limiting the side effects of treatment. SRS is frequently used in the setting of lung cancer, which is associated with greater rates of BM, though its cost may lead to potentially inequitable use across patient populations. This study investigates potential disparities in the use of SRS to treat Medicare patients. Surveillance, Epidemiology, and End-Results cancer registry data for patients diagnosed between the years 2010 and 2012 were examined to identify lung cancer patients diagnosed with BM at the same time as their primary cancer (SBM). Medicare claims for SRS were identified; the odds of having SRS claims and hazards of mortality associated with those odds were examined with respect to various clinical and demographic characteristics. Of 74,142 Medicare-enrolled patients diagnosed with lung cancer, 9192 were diagnosed with SBM and 3259 of those patients received SRS. Adjusting for clinical and demographic characteristics, males with SBM had 0.85 times the odds of SRS compared to females with SBM. Black patients and those of other race had significantly lower odds of evidence of SRS compared to WNH patients. SRS may not be delivered equitably among Medicare patients. Males and minority patients may have decreased odds of SRS and worse survival compared to female and WNH patients, respectively.