AREAL facility as a source of ultrashort pulsed electron beams and its contribution to radiobiological studies

The purpose of this review was to summarize recent studies on the radiobiological effects of ultra-short pulsed electron beams and to determine whether intra-pulse parameters, such as dose-per-pulse and pulse width, may underlie the FLASH effect more than mean dose-rate. The in vitro and in vivo findings uniquely enabled by the AREAL ultra-short pulsed electron beam (UPEB) platform are reviewed.

At clinically relevant dose-rates, UPEBs produce more complex, less repairable DNA damage than quasi-continuous irradiation delivered by clinical LINACs. The long-term genomic alterations in vitro, and distinct, partially recovering oxidative and hematopoietic responses in vivo were observed, implicating pulse duration and peak dose-rate as primary drivers of effect. AREAL provides a uniquely controlled setting to isolate dose-per-pulse and pulse width as independent variables, enabling mechanistic studies of the parameters underlying the FLASH effect.