ABSTRACT
In recent years, ultra-high dose rate (FLASH) radiotherapy has become one of the most advanced research topics in the field of radiotherapy. Experimental data indicate that FLASH radiotherapy can significantly reduce the irradiation damage in normal tissues while being as effective as clinical conventional dose rate radiotherapy in tumor control. The oxygen depletion hypothesis is considered as one of the key mechanisms underlying the FLASH effect. In this article, research progress on the discovery, experimental evidence and reaction principle of oxygen depletion was reviewed, the measurement methods and biological effect modeling methods of the oxygen depletion hypothesis were summarized, and the oxygen depletion difference between normal tissue and tumor was also discussed.