Resumen
Ultra-high dose-rate (UHDR) irradiation can lead to a FLASH-effect which reduces the biological effect on healthy tissue without affecting the dose to the tumor. UHDRs can currently be achieved using 250 MeV (transmission) proton beams. Up until now, suggested treatment sites potentially benefiting from a FLASH effect include, e.g., small lung, skin, and brain tumors. We suggest the use of FLASH for breast tumors because almost the entire target consists of healthy tissue and hypofractionated dose schedules are common. In this study, we demonstrate that whole breast irradiation (WBI) can be performed using a single transmission proton beam. We evaluated the necessary proton beam parameters in order to achieve the maximum FLASH-effect according to our current knowledge. Although currently not clinically applicable, we hypothesize that a potential FLASH-effect can even allow for further hypofractionation of WBI.