Razi Journal of Medical Sciences

  Background & Aim: Nowadays, radiosensitive polymer gels are used as a reliable dosimetry tool for verification of 3D dose distributions. Polymer gel dosimeters consist of an aqueous mixture of monomers and a gelling agent, which after irradiation, 3D dose distribution is acquired by using imaging techniques. The aim of this study is to evaluate the application and capability of normoxic polymer gel to determine electron 3D dose distributions at depths of 1 and 4cm beneath the homogenous phantom at 8 and 15 MeV energies.

  Material and Method: In this descriptive study, we used MAGIC-type gel dosimeter to measure dose distribution at depths of 1 and 4cm underneath homogeneous slab phantoms by using MRI. The homogenous phantoms were irradiated by 8MeV and 15MeV electron beams. Paired sample t-test and Pearson correlation coefficient were used to analyze the results.

  Results: Dose resolution at the range of 0 to 10Gy was 0.23 to 1.55Gy. The mean dose differences and the maximum distance to agreement (DTA) of dose profiles for two diode and gel measurements were 2.5% and less than 2mm, respectively. In addition, 3D dose distribution was obtained at two orientations: transverse and axial.

  Conclusion: This study shows the feasibility of using gel dosimeters to evaluate dose distribution for different electron beams.