ABSTRACT
Oxygen is the prime mover of radiosensitization, increasing the biological eect of ionizing radiation by a factor of 2 to 3, whereas radioresistance is associated with hypoxia. It was shown that the oxygen eect only occurred if oxygen is present during irradiation or within a few milliseconds, implying that the mechanism is mediated by short-lived free radicals. e mechanism to be responsible for the enhancement of radiation damage by oxygen, is generally referred to as the oxygen-xation hypothesis (OFH) and was developed in the late 1950s from the work of Alexander and Charlesby [1] (as reviewed by Ewing [2]).
