Consensus statement on the exploration of clinical translation and application of electron ultra-high dose rate FLASH radiotherapy

Ultra-high dose rate FLASH Radiotherapy (FLASH-RT) has attracted wide attention because the well-known FLASH effect and the extremely short irradiation time. During FLASH-RT, high radiation doses and dose rate (usually thousands of times compared with conventional radiotherapy (CONV-RT)) are delivered to the tumor area. This novel irradiation technique shows a reduction of normal tissue injury (20-40%) in comparison to CONV-RT. Meanwhile, FLASH-RT maintaining comparable tumor killing effect as CONV-RT. With the progress of basic research on FLASH-RT in reducing radiation-induced injury to normal tissues, clinical trials of FLASH-RT have been carried out across the world. To date, there is no consensus in China focused on the exploration of clinical transformation and application of electron FLASH-RT. Therefore, the China Anti-Cancer Association Radiation Oncology Committee and the Chinese Medical Doctor Association Radiation Oncology Physician Committee gathered a group of experts together to develop this consensus statement. The authors discuss their current views on electron FLASH-RT, demonstrate the unresolved questions, provide insights for the further application of this technology in clinical practice.