Modeling and detection of acoustic waves induced by ultra-high-dose-rate electron beams from a radiotherapy linear accelerator.

FLASH radiotherapy (FLASH-RT), as a burgeoning and promising cancer treatment approach, spares normal tissues from radiation damage by delivering ultra-high doses to tumors within an extremely short duration, without compromising anti-tumor efficacy. Specifically, electron-based FLASH-RT can be used to treat superficial skin cancers, offering unique advantages in clinical radiotherapy. To enhance understanding of the physical characteristics of acoustic waves induced by ultra-high-dose-rate pulsed electron-beam irradiation, this study developed an integrated simulation workflow based on Monte Carlo and k-space pseudospectral methods. This computational framework enables full end-to-end simulation of single-pulse dose delivery to a target in electron-based FLASH-RT, followed by the spatial propagation and attenuation of the resulting acoustic waves. To capture acoustic waves generated by single-pulse irradiation from a linear accelerator, a dedicated data acquisition (DAQ) system was also designed and implemented based on analysis of simulated acoustic signal characteristics. The differences between simulated and experimental signals across multiple domains were compared under various conditions. The developed simulation workflow and DAQ system facilitate a comprehensive study of the physical properties of acoustic waves induced by ultra-high-dose-rate pulsed electron-beam irradiation and the development of an electron-based FLASH-RT dosimetry system.