Radiotherapy has not stopped evolving since the last century. From the increase in photon energy to the emergence of heavy
particles, treatments have become more and more conformal. These improvements have led to greater outcomes and reduced toxicity (1).
Recently, following pre-clinical trials (2) (3) (4) and treatment of the first human patient (5), Flash radiotherapy (Ultra-short
pulsed high dose rate radiation therapy) has created a ripple effect in the radiation therapy community (6). Strikingly, these studies
reported a significant decrease in toxicity, whereof the mechanism is still not fully understood, while maintaining efficient
anti-tumor activity. If these results could be confirmed by other studies on humans this would cause a genuine revolution in the
field. In this dose-escalation study we plan to irradiate symptomatic superficial or cutaneous lesions. In the preclinical part of
this project, we aim to unravel the exact mechanisms underlying FLASH-RT effect.