Regional disparities in trends of Medicare reimbursements and service volumes for stereotactic radiosurgery among neurosurgeons and radiation oncologists, 2014-2022.

e23051 Background: Stereotactic radiosurgery (SRS) is a minimally invasive alternative to traditional brain surgery for treating intracranial neoplasms. While SRS often involves collaboration between neurosurgeons and radiation oncologists, no studies have explored geographic variations in reimbursement rates or neurosurgical involvement in SRS delivery. Methods: The Medicare physician fee schedule was used to extract data on inflation-adjusted reimbursement rates by locality for CPTs 61796 (SRS for 1 simple cranial lesion, neurosurgery) and 77372 (SRS for single session, radiation oncology) from 2014 to 2022. Medicare Public Use Files provided state-level service volume data for CPTs 61796, 61798 (complex lesion, neurosurgery), 77432, and 77435 (SRS for multiple sessions, radiation oncology). Reimbursement rates and service volumes were averaged by state and analyzed by U.S. Census Region (Northeast, Midwest, South, West). Multivariate linear regression analyzed trends with region, specialty, and year as covariates. Results: From 2014 to 2022, average pooled national reimbursement rate across neurosurgeons and radiation oncologists fell by $34.57/year ($1,301.02 [2014] vs. $1,027.63 [2022], P < 0.001). Multivariate linear regression with region, specialty, and year as covariates demonstrated that physicians in the Midwest ($1,125.27) received lower average reimbursement rates than those in the Northeast ($1,256.72; β = $131.44 [95% CI: $111.12 - $151.78], P < 0.001), West ($1,215.05; β = $89.78 [$69.44 - $110.11], P < 0.001), and South ($1,150.58; β = $25.31 [$4.97 - $45.64], P < 0.05), and neurosurgeons ($1,173.02) received lower reimbursement rates than radiation oncologists ($1,200.80; β = $27.78 [$13.40 - $42.16], P < 0.001) (Table 1 and Figure 2). National SRS treatment volumes increased from 30,392 to 53,700 (P < 0.001) over the study period, while neurosurgeon involvement in SRS treatment decreased from 31.44% to 16.41% of all cases (P < 0.001). Finally, average neurosurgeon involvement in SRS treatment was higher in the Northeast (26.12%; β = 0.06 [0.05 - 0.07]), West (24.20%; β = 0.041 [0.03 - 0.051]), and South (21.95%; β = 0.018 [0.008-0.029]) than the Midwest (20.13%) (all P < 0.001). Conclusions: Regional disparities exist in reimbursement rates and neurosurgical involvement in SRS delivery. Efforts to achieve geographic parity in these measures are crucial to ensuring equitable access to neuro-oncological care.