Executive summary

This study reported that proton-FLASH (>60 Gy/s) was more effective in reducing tumor burden and decreasing tumor cell proliferation compared conventional proton irradiation (<0.05 Gy/s) based on a mouse model of NSCLC. Proton-FLASH was more efficient in increasing the infiltration of cytotoxic CD8+ T-lymphocytes inside the tumor while simultaneously reducing the percentage of immunosuppressive regulatory T-cells (Tregs) among T-lymphocytes.