Behaviour and mechanism of micelle gel dosimeter for carbon-ion-beam irradiation

Abstract

Micellar gel dosimeters can measure complex three-dimensional dose distributions. However, they have rarely been applied to measure radiation other than X-rays. In this study, we evaluated the radiological characteristics of a micelle gel dosimeter for clinical carbon-ion-beam irradiation. We irradiated a micelle gel dosimeter with a carbon ion beam and determined the reaction rate of the dye by measuring the absorbance after irradiation. In the micellar gel dosimeter used, a drastic change in the reaction rate was observed near the Bragg peak predicted in the treatment plan. In addition, chemical species generated during carbon-ion-beam irradiation were predicted by Monte Carlo simulations. When the measured and calculated results were compared, the reaction rate of the micelle gel dosimeter showed a correlation with the amount of OH radicals generated by the carbon ion beam. The results of this study will help expand the application range of micelle gel dosimeters in cancer therapy.