Feasibility assessment of polycrystalline CsPbI₃ relative dosimeters in photon and electron beam radiotherapy

Abstract Volumetric modulated arc therapy represents the latest technology in radiotherapy. It involves continuous modification of the multi-leaf collimator spatial distribution, dose rate, and gantry rotational speed, necessitating a dosimeter with high spatial resolution and exceptional sensitivity per unit volume. In particular, cesium-based inorganic perovskites have been studied for various applications, spanning from photoconductor solar cells to radiation detectors. These perovskites are renowned for their outstanding attributes, including thermal stability, inorganic stability, and light absorption capacity. Despite such advantageous characteristics, CsPbI3 materials have only been investigated in radiodiagnostics, with limited exploration in radiotherapy. To address this gap, this study verified the viability of CsPbI3 materials, note for their outstanding radiation detection efficiency, as dosimeters capable of measuring the radiation detection performance for radiotherapy devices. The reproducibility, linearity, and percent depth dose (PDD) were evaluated under the application of photon and electron beams in linear accelerators. The reproducibility assessment revealed impressive results, with the relative standard deviation registering at 0.53%, 0.32%, and 0.38% under electron beam energies of 6, 9, and 12 MeV and 0.45%, and 0.89% under photon beam energies of 6 and 15 MV. Moreover, the linearity test revealed an R 2 value of 0.9999, indicating high linearity, at 6, 9, and 12 MeV and at 6 and 15 MV. The PDD graphs drawn for the CsPbI3 dosimeter fabricated in this study showed that the D max points were consistent. The novel CsPbI3 dosimeter demonstrated a level of detection performance that satisfied all criteria; reproducibility, linearity, and PDD. The results collectively indicated that the CsPbI3 dosimeter can be used for dosimeters in radiotherapy devices.