Non-diffusing radiochromic leuco-crystal violet hydrogel dosimeter

Abstract

A systematic study to prepare mixed-micelle, radiochromic hydrogels found that non-diffusing dosimeters can be prepared. Subsequent experiments determined that sodium dodecyl sulfate (SDS) a negatively charged surfactant, binds positively charged crystal violet dye to gelatin below the critical micelle concentration. A typical formulation includes: 4% gelatin by mass, 1 mM hydrogen peroxide, 1 mM SDS, 1 mM leuco crystal violet (LCV) and 25 mM trichloroacetic acid (TCAA). This transparent material has an initial attenuation coefficient of 0.08 cm-1 and dose sensitivity of 0.015 cm-1 Gy-1. Which is a doubling of the dose sensitivity from the initial formulation with uncharged Triton X100 micelles. Reconstructed beam profiles from 3D optical CT scans performed 1, 14 and 85 hours post irradiation demonstrate no diffusion of the recorded dose distribution.