Establishing an Electron FLASH Platform for Preclinical Research in Low-Resource Settings

Background: FLASH radiotherapy delivers ultra-high dose rates with normal tissue sparing, but mechanisms remain unclear. We present a streamlined workflow for establishing a LINAC-based electron FLASH (eFLASH) platform in low-resource settings without requiring vendor-proprietary hardware or software, or vendor-assisted modifications to broaden accessibility for FLASH studies. Methods: A LINAC was converted to eFLASH with pulse control and monitoring. Automatic frequency control (AFC) was optimized to stabilize dose per pulse (DPP). Beam data were measured with EBT-XD films, and a Monte Carlo (MC) model was commissioned for in vivo dose calculation. We demonstrated in vivo dosimetry in planning studies of mouse whole-brain and rat spinal cord (C1–T2) irradiation. We further assessed the impact of AFC optimization on the FLASH spinal cord study. Results: AFC optimization stabilized DPP at ~0.6 Gy/pulse, reducing large fluctuations under the default setting. MC agreed with measurements within 2% for PDDs and profiles. MC planning showed uniform whole-brain irradiation with 6 MeV FLASH, while the spinal cord study exhibited up to 10% dose fall-off within 1 cm along the cord, suggesting potential dose-volume effects confounding FLASH sparing. Following AFC optimization, 50% of the C1–T2 cord reached >133 Gy/s, a 23% increase versus default. Conclusions: We demonstrated a cost-effective eFLASH platform and verified its accuracy for preclinical studies, expanding the accessibility of FLASH research.