Over the last three years, significant progresses have been made in understanding the FLASH mechanisms, spanning over physics, chemistry, and biology. The particle-agnostic nature of the FLASH effect has been conclusively demonstrated, yet the quest for defining the optimal beam parameters is ongoing. Explorations into chemical hypotheses, including oxygen depletion and oxidation reactions on biological components, have expanded our understanding and comprehensive investigations into biological responses, ranging from immune and inflammatory reactions to vascular and redox responses, have also been undertaken and are ongoing.

Mechanism tracks will offer insights into the latest advancements in the field.