Novel radiochromic gel dosimeter based on a polyvinyl alcohol - Iodide complex

摘要

We propose a novel radiochromic gel dosimeter utilizing the red color developed by the complexation of polyvinyl alcohol and iodide (PVA-I) in an aqueous gel matrix. The fundamental optical dosimetric properties and the influence of the composition on those properties are investigated by observing the change in optical absorbance of the gel dosimeters irradiated by a high-energy photon beam. Our results suggest that the PVA-I radiochromic gel dosimeter has numerous desirable properties as a dosimeter, such as high sensitivity, transparency, dose rate independence, temporal and spatial stability, water equivalence, and a wide effective dose range. Moreover, the PVA-I radiochromic gel dosimeter can be initialized (decolorized) by heating and is reusable. These excellent characteristics demonstrate its potential for use in three-dimensional gel dosimetry based on optical computed tomography in high-precision radiotherapy.