FIG. 1.

Effect of proton-FLASH-RT on normal cellular growth and ROS level. Panels A and B: Viability of IMR90 cells exposed to 15 Gy protons delivered at either 0.03 Gy/s or 100 Gy/s and fixed up to day 7 postirradiation. Panel C: Cell proliferation determined by CCK-8 at either 2 h or 12 h postirradiation. Panel D: CM-H2DCFDA level change, relative to control, after 15 Gy proton irradiation delivered at 0.03 Gy/s or 100 Gy/s and assayed 40 min or 24 h postirradiation with or without N-Acetyl-L-cysteine (NAC). *P ≤ 0.05; **P ≤ 0.01. For each sample, three replicates were analyzed and three independent experiments were performed.