Stereotactic radiosurgery for brain metastases: evolving practice patterns from the national cancer database (2004–2020)

Stereotactic radiosurgery (SRS) offers less neurotoxicity and comparable survival to whole-brain radiation therapy (WBRT) for brain metastases (BM). Current SRS practice patterns are understudied. We examined national trends in SRS and WBRT utilization. We queried the National Cancer Database for patients with BM from twelve cancers (≥ 18 years; diagnosed 2004–2020) treated with radiotherapy. Patients were grouped by first-course radiotherapy modality (SRS:1–5 fractions; WBRT:5–15 fractions). Multivariable logistic regression assessed SRS predictors, adjusting for sociodemographic and clinical variables. A race*diagnosis year interaction evaluated temporal trends. Difference-in-differences analysis assessed Medicaid expansion impact. Of 89,984 patients, 24,174 (27%) received SRS. SRS utilization rose from 8 to 54% between 2004 and 2020 (P < 0.001). SRS was more likely in patients diagnosed in recent years (aOR = 3.85 [95% CI = 3.70–4.01]), who received prior chemotherapy (aOR = 1.17 [1.13–1.21]) or surgery (aOR = 2.25 [2.11–2.40]), and those with colorectal (aOR = 1.93 [1.64–2.26]), lung (aOR = 1.37 [1.24–1.50]), melanoma (aOR = 2.76 [2.46–3.10]), thyroid (aOR = 2.17 [1.36–3.46]), or kidney/bladder cancer (aOR = 2.76 [2.44–3.12]) versus breast cancer. SRS was less likely in patients with lower income (aOR = 0.88 [0.85–0.92]) or educational attainment (aOR = 0.88 [0.85–0.92]), Medicaid/Medicare (aOR = 0.86 [0.83–0.90]), no insurance (aOR = 0.49 [0.44–0.53]), or treatment at community (aOR = 0.31 [0.29–0.34]), comprehensive community (aOR = 0.56 [0.54–0.58]), or integrated facilities (aOR = 0.77 [0.73–0.80]). Race and ethnicity were not overall associated with SRS use. Medicaid expansion had no impact (aOR = 0.99 [0.88–1.10]). SRS utilization increased between 2004 and 2020. However, disparities persist for patients with lower socioeconomic status, uninsured/public insurance, or non-academic center treatment, potentially reflecting access disparities or differences in disease burden. Targeted efforts are needed to ensure equitable access to advanced cancer therapies, particularly in the context of potential additive effects of disparities in disease burden.