Intracellular oxygen transient quantification in vivo during Ultra-High Dose Rate (UHDR) FLASH radiotherapy

Large, rapid extracellular oxygen transients ( ΔpO2) have been measured in vivo during Ultra-High Dose Rate (UHDR) radiotherapy; however, it has been unclear if this matches intracellular oxygen levels. Here, the endogenously produced Protoporphyrin IX (PpIX) delayed fluorescence (DF) signal was measured as an intracellular in vivo oxygen senso r to quantify these transients, with direct comparison to extracellular pO2. Intracellular ΔpO2 is closer to the cellular DNA, the site of major radiobiological damage and therefore should help elucidate radiochemical mechanisms of the FLASH effect and potentially be translated to human tissue meas urement.
Source: International Journal of Radiation Oncology * Biology * Physics - Category: Radiology Authors: Tags: Physics Contribution Source Type: research