Annealing properties of the PVA-GTA-I gel dosimeter

Abstract The feature of reusability of a gel dosimeter is of particular interest for application to three-dimensional dosimetry in clinical settings. As one of the reusable materials, the radiochromic gel formula composed of polyvinyl alcohol (PVA), glutaraldehyde (GTA), and iodide (I), abbreviated as “PVA-GTA-I gel dosimeter”, is investigated in the present study. The annealing properties of the PVA-GTA-I gel were examined for energetic X-rays from a medical linear accelerator, while its reusability was confirmed for 137Cs-source γ-rays. The radiation-induced colorings of the PVA-GTA-I gel irradiated with few Gy were erased within several hours, while the reactions induced by higher dose (∼20 Gy) were more persistent and required longer time up to 24 h to be completely reversed. The linear dose response of the PVA-GTA-I dosimeter was well reproduced after repetition of annealing.