Research and development of PVA-KI gel dosimeter

In cancer radiation therapy, the visualization of radiation patterns is absolutely necessary for precisely evaluating the dose distribution and improving dose targeting. Recently, we developed a new type of gel dosimeter that uses color changes produced by iodine reaction with polyvinyl alcohol (PVA) that allows dose visualization. This gel has high transparency and is clear at zero dose. In addition, the gel can be manufactured at low cost, easily, and safely in comparison with existing gel type dosimeters. In this study, we irradiated PVA-KI gels with X-rays from a generator and γ-rays from a Co-60 source, and evaluated the color changes on dose by absorbance using UV-VIS spectrophotometry. Additionally, we looked at the dose-rate dependence and energy dependence of the gel from results of irradiation with X-rays and γ-rays. The results showed that the gel has a linear response and repeatability when exposed to radiation and useful for visualization of dose distribution.