Figure 1
Ultra-high dose rate (35 Gy/s) RT is more potent than conventional dose rate (0.1 Gy/s) RT in killing tumor cells, with no appreciable difference in modes of cell death. (a) Clonogenic survival curve of KPC cells treated with ultra-high dose rate shows enhancement factor at 10% surviving fraction (DEF10) of 1.310 compared to conventional dose rate RT(0,2,4,6,8 Gy of radiation) (b) Clonogenic survival curve of Panc02 cells treated with ultra-high dose rate shows enhancement factor at 10% surviving fraction (DEF10) of 1.365 compared to conventional dose rate RT(0,2,4,6,8 Gy of radiation) (c,d) The percentage of PBMCs undergoing early apoptosis, late apoptosis, and necrosis at 24 h and 72 h following ultra-high and conventional dose rate RT. Dose enhancement ratio at survival fraction (DERSF0.1) of 10% was calculated by (radiation dose needed to kill 90% at high dose-rate)/(radiation dose needed to kill 90% with conventional dose rate). The radiation dose was calculated from the linear quadratic model based on the survival fraction at each dose. Data are derived from experiments conducted in sextuplicate.
