Monte Carlo track-structure simulation of the impact of Ultra-Hight Dose Rate and oxygen concentration on the Fenton reaction

UHDR reduces the yield of Fe³⁺ (G(Fe³⁺)) and significantly impacts Fenton reactions, particularly at low oxygen concentrations, while showing minimal effects at higher oxygen levels. This effect becomes more pronounced at higher dose thresholds, such as 10-20 Gy. This emphasizes the important role of the initial oxygen concentration in UHDR and its influence on the Fenton reaction, a mechanism that may contribute to elucidate the FLASH effect.