RESUMO
Flash radiotherapy (Flash-RT) is a treatment modality that uses the normal tissue sparing regimen induced by ultra-high dose rate and ultra-fast irradiation. Compared to conventional dose rate radiotherapy, Flash-RT has the potential to provide the isoefficacy for tumors while achieving the remarkable normal tissue protection. Due to this unique feature, Flash-RT is attracting more and more attention from the radiotherapy community. An abundance of groups from both academia and industry are extensively studying the therapeutic ratio and underlying biological mechanisms. Here, we review the prior knowledge about Flash-RT and summarize the results that have been reported from various groups using both in vitro and animal studies with different experimental protocols. We also discuss possible biological mechanisms and the challenging of implementing Flash-RT, as well as its possible options for clinical applications.