Dosimetric evaluation of the PASSAG polymer gel dosimeter improved with sucrose using MRI

One of the main constraints of polymer gel dosimeters for use in clinical settings is the high toxicity of their compounds. PASSAG gel dosimeter provides excellent dosimetric properties and very low toxicity. However, its major limitation is poor response-dose sensitivity. This work aimed to find if adding sucrose to its conventional formulation raises the response-dose sensitivity. New formulations of PASSAG gel dosimeter (PASSAG-S, PASSAG and sucrose) were initially constructed and then exposed to various radiation doses. A 1.5 T magnetic resonance imaging scanner was applied to read out the responses ( R 2 ) of the gel-containing tubes after the irradiation. In this regard, the R 2 -dose response and sensitivity of conventional formulation and new formulations of PASSAG gel dosimeter with 1, 3, and 5 wt% sucrose were studied at different times after the irradiation and various scanning room temperatures. Compared to the conventional gel dosimeter formulation, there were increased sensitivities of 11.37 %, 20.40 %, and 26.14 % for PASSAG-S gel dosimeter formulations with 1, 3, and 5 wt% sucrose, respectively. The study also found the following dosimetric findings for various formulations of PASSAG-S gel dosimeter: a) the great linear R 2 -dose responses in a dose range of 0–10 Gy; b) the relative stability in their sensitivity over a vast range of scanning room temperatures (15–18 °C and 20–24 °C); c) the temporal stability at their responses during various post-irradiation times. Our findings showed that adding sucrose to the conventional formulation of the PASSAG gel dosimeter enhances its response-dose sensitivity. While sucrose increases the sensitivity of the PASSAG-S gel dosimeter, it causes dose resolution to degrade (particularly for 5 wt% sucrose). So, the researchers considered a 3 wt% sucrose as the optimal concentration for the new gel dosimeter formulation. • An improvement study was done on PASSAG gel dosimeter. • Different concentrations of sucrose (1, 3, and 5 wt%) were evaluated. • A 3 wt% sucrose was considered as the optimal concentration for the new gel dosimeter formulation. • The improved PASSAG gel dosimeter (3 wt% sucrose) showed a 20.40 % increase in R 2 -dose sensitivity.