Water equivalence of micelle gels for x-ray beams

T Gorjiara,S Bosi,R Hill,C Baldock,Z Kuncic

doi:10.1088/1742-6596/444/1/012024

Abstract

Micelle gel is a radiochromic hydrogel with the potential to be used as a three dimensional (3D) radiation dosimeter. Since an ideal dosimeter should present water equivalent properties, in this study the water equivalence of two formulations of micelle gel has been investigated by calculating electron density, effective atomic number, fractional interaction probabilities, mass attenuation coefficient. The depth doses for kilovoltage and megavoltage x-ray beams have also modelled using Monte Carlo code. Based on the results of this work, micelle gels can be considered as water equivalent dosimeters.

Highlights

Polymer gel dosimeters are manufactured from radiation sensitive chemicals, which upon irradiation polymerize as a function of the absorbed radiation dose [1]
Jordan et al used leuco Malachite Green (LMG) dye which converts to Malachite Green (MG+) after exposing to ionizing radiation
Electron density of LMD1 and LMD2 is slightly higher than water by 1.4% and 0.9% discrepancy, respectively

Summary

Introduction

Polymer gel dosimeters are manufactured from radiation sensitive chemicals, which upon irradiation polymerize as a function of the absorbed radiation dose [1]. Jordan et al used leuco Malachite Green (LMG) dye which converts to Malachite Green (MG+) after exposing to ionizing radiation This gel (will be referred as LMD1) contains trichloroacetic, Triton X-100 and gelatine and has an absorption peak of 633 nm which is suitable to be readout by optical scanners [15]. Due to high dose rate dependency of the initial composition of leucodyes gels, a modified composition was suggested [16] This new formulation of LMG (will be referred as LMD2) contains sodium dodecyl sulphate, chloroform, trichloroacetic acid, gelatine and LMG and shows good spatial stability and no energy dependency for megavoltage x-ray beams [17].!!

Methods

Results

Conclusion