Comparison of dose rate dependence in MAGICA and PAGAT gel dosimeters (Soft Tissue Equivalent) with electron beams using MRI

Abstract

The purpose of this study was to evaluate the dependence of MAGICA and PAGAT polymer gel dosimeters 1/T2 on different electron energies in order to compare the dose rate dependence of MAGICA and PAGAT polymer gel dosimeters in electron beams using MRI technique for a standard clinically used an ELEKTA linear accelerator. Using MRI, the formulation to give the maximum change in the transverse relaxation rate R2 (1/T2) was determined MAGICA gel dosimeter and PAGAT gel dosimeter. In this work the response of MAGICA gel is very similar in the lower dose region and the R2-dose response for doses less than 250cGy is not exact. Dose rate of dependence was studied in 10MeV electron beam with the use of dose rates 80,160,240,320,400 and 480MU/ min. The response of PAGAT gel is very similar in the lower dose region and the R2-dose response of the PAGAT polymer gel dosimeter is linear between 10 to 30Gy and dose rate dependence was studied in 6MeV electron beam with the use of dose rates 80, 160, 240, 320, 400 and 480cGy/min. In this study no trend in polymer-gel dosimeter for MAGICA and PAGAT 1/T2 dependence was found on mean dose rate for electron beams.