FLASH-Radiotherapy: A Potential Innovation Driver in Radiation Therapy

In recent times, radiation therapy (RT) involving ultra-high dose rates of ionizing radiation, known as FLASH-RT, has been of great interest. Through this technology, the radiation dose can be delivered almost instantaneously within milliseconds. Many in vitro and in vivo studies have demonstrated that FLASH-RT can significantly improve normal tissue tolerance from radiation induced toxicity; this improvement is called the FLASH effect. Very recently, encouraging results from FLASH-RT on human patients have been reported, which has extended the applicability of FLASH-RT to clinical practice. In this review, we will discuss the results of the current research on FLASH-RT and consider the challenges to be overcome prior to the clinical application of FLASH-RT.