Feasibility of a Tungsten Rubber Grid Collimator for Electron Grid Therapy

Abstract

BACKGROUND/AIM: Spatially fractionated radiotherapy (grid therapy) can control some bulky tumors which is challenging for conventional radiotherapy. This study aimed to investigate whether a novel tungsten contained rubber (TCR) grid collimator can be employed in electron grid therapy. MATERIALS AND METHODS: The TCR grid collimator placed on a solid water phantom, and percentage depth doses (PDDs) and lateral dose profiles were measured for 9 MeV electron beam with Gafchromic EBT3 films. At the lateral dose profile, the ratios of the dose in the areas with and without shielding (valley-to-peak ratios) were evaluated. RESULTS: were 0.566, 0.412 and 0.293, respectively. CONCLUSION: Only the 2 mm TCR grid collimator had adequate dosimetric features compared to the conventional grid collimator and could be substituted.