Table III.

Comparison of Con-RT and FLASH-RT.

Item	Con-RT	FLASH
Equipment	Proton and ion accelerator, X-knife, γ-knife,	Proton accelerators, linear accelerator
Cost	Proven equipment, technology, research and clinical translation	Higher technology cost, equipment cost, personnel cost, research cost, automation and clinical efficiency
Dose rate, Gy/sec	0.002-0.017	>40
Ray	X- and γ-ray, proton, heavy ion, electron	Proton, X-ray, electron
Time, sec	≥120	<1
Tumor control effect	Efficient	Efficient
Damage degree of normal tissue	High	Low
Factors	Tissue radiosensitivity, dose	Dose, dose segmentation, oxygen content, pulse
Mechanism	Oxygen depletion hypothesis, ROS, immunoinflammatory hypothesis	Repair, reoxygenation, redistribution, repopulation, oxygen depletion hypothesis, ROS

Con-RT, conventional radiotherapy; ROS, reactive oxygen species.