Suitability Assessment of CsPbI_3 Dosimeter with ^192Ir Source for Brachytherapy Quality Assurance

Abstract

In brachytherapy, quality assurance (QA) is a prerequisite to minimize the dose irradiation to the healthy tissues in patients during treatment, as it evaluates the accuracy of the dose applied to the patients as well as the accuracy of the position of the irradiation. Therefore, a strong emphasis has been placed on brachytherapy QA in clinical practice. This study assessed the suitability of a CsPbI3 dosimeter for the brachytherapy QA system. To verify the reliability of the unit cell sensor fabricated with CsPbI3, the electrical parameters were evaluated, after which the position dependence of the sensor was analyzed. A high level of reliability (R 2 > 0.99) and reproducibility (relative standard deviation < 1.5%) were observed. The maximal value measured at the isocenter of the sensor as the distance of the dosimeter from the irradiation source was gradually decreased. When the optimal angle was assessed, the variation was as high as 5.01 nC depending on the form of the 192Ir source. Therefore, the CsPbI3 dosimeter fabricated in this study is a suitable substitute for the conventional QA dosimeter.