Characterization of Radiochromic Hydrogel Dosimeter-Ferrous Xylenol Orange Enhanced to Have a Higher Melting Point

Abstract

Ferrous xylenol orange (FXO) radiochromic gelatin gel dosimeter has the potential to provide tridimensional dosimetry for the assessment of new technologies of treatment in radiotherapy. However, one problem with the present formulations of these gels is the low melting point of the gelatin matrix. To solve this problem, formaldehyde was added to this gel dosimeter to promote crosslinking in the gelatin matrix, thus increasing the melting point. Five different formulations of FXO gel were tested, the best melting point temperature found was 62 °C or higher, and the 0.210 mm²/hr of diffusion rate was obtained on the 8% gelatin with 3% formaldehyde, 75% lower than original formulation. To provide clinical uses of these dosimeters, this work deals with the dosimetric characterization of modified FXO. No energy dependence was found when irradiated with 6 MV and 15 MV beams; also, no dose rate dependence was found varying low to high dose rate, 100 to 1400 cGy/min. These characteristics allow this dosimeter to useful for clinical context.