Applications of Polarization Imaging for Conventional and FLASH Radiotherapy Dosimetry

Abstract

The application of Cherenkov radiation in radiation therapy dosimetry has been limited by the anisotropic nature of the signal. Recently, polarization imaging was investigated as a method to correct Cherenkov anisotropy and allow precise dose measurements directly in a water tank. The aim of this study is to present polarization imaging as method for the measurement of ultra-high dose rate (UHDR) intra-operative electron beams. In this new approach, the polarized Cherenkov signal was isolated and utilized as a surrogate to evaluate the quality and consistency of both UHDR and conventional electron beams. Percent depth Cherenkov signal were measured for different energies, field sizes and dose rates. The results demonstrate high linearity (R 2 > 0.99) of the Cherenkov signal with the number of pulses and pulse width. The wide dynamic range of the device enabled measurement for both conventional and UHDR radiation beams making it a promising candidate for real-time quality assurance devices.