Everything the Light Touches: Radiation Oncology Access and Availability in the State of Oregon

Oregon's vast and complex terrain creates potential barriers for patients needing daily radiotherapy. The large geographic area and the lack of a standardized database to guide referrals make navigating regional radiation oncology (RO) resources and understanding treatment access across the state challenging.

This is a cross-sectional statewide analysis of RO centers and physicians in Oregon using geospatial information software to estimate resident-level access, RO center-specific capability, and facility-level population coverage by distance and drive-time in 2025. Additionally, regional all-cancer outcomes are summarized by mortality-to-incidence ratios (MIRs) based on proximity to RO access.

Oregon has 27 active RO centers, with a recent closure in Pendleton that previously served approximately 110,000 residents. Although 71% of the population lives within 10 miles of an RO facility, 54.5% of the state's land area lacks proximal access, leaving 434,855 residents (10.3%) more than 60 minutes from care. For many counties, the nearest center is located out-of-state at distances up to 137 miles. One-way drive-times vary widely but can exceed 2.5 hours. Despite statewide resource levels exceeding national averages (one linear accelerator per approximately 83,000 residents and one radiation oncologist per approximately 49,000 residents), there is limited access to brachytherapy and no proton therapy centers. Additionally, increasing geographic isolation from RO access is ecologically associated with worse all-cancer MIRs.

This study provides a comprehensive characterization of RO resources across Oregon. Results reveal substantial regional disparities in proximity, treatment capability, and outcomes, particularly in rural/remote counties that lack in-state RO options. By integrating geospatial, population, and outcome data, this work establishes a statewide baseline to identify persistent access gaps and serves as both a referral resource and a framework for future access studies.