Development of a silicone-based radio-fluorogenic dosimeter using dihydrorhodamine 6G

Abstract

A silicon-based three-dimensional dosimeter can be formed in a free shape without a container and deformed because of its flexibility. Several studies have focused on enhancing its radiological characteristics and assessing its applicability as a quality assurance tool for image-guided and adaptive radiation therapy, considering motion and deformation. Here, we applied a fluorescence probe (dihydrorhodamine 6G, DHR6G) to a silicon elastomer as a new radiosensitive compound that converts nonfluorescent into fluorescent dyes using irradiation, and its fluorescence intensity increases linearly with the absorbed dose. In this study, we demonstrated a cost-effective synthesis method and optimized the composition conditions. The results showed that the DHR6G-SE prepared from 2.2 × 10^-3 wt% DHR6G, 0.024 wt% pyridine, and a silicone elastomer (SE) (SILPOT TM 184, base/curing agent = 10/1) exhibited a linear increase in fluorescence with radiation exposure within a dose range of 0-8 Gy and a highly stable sensitivity for as long as 64 h. To demonstrate its container-less characteristics, the possibility of dosimetry for low-energy X-rays using DHR6G-SE was investigated.

Keywords: Dose response; Fluorescence probe; Gel dosimetry; Silicon dosimeter; Stability; Synchrotron X-ray.