Radiation‐sensitive nanogel‐incorporated Fricke hydrogel dosimeters with reduced diffusion rates

Abstract

Fricke gel dosimeters have great potential for three‐dimensional (3D) dose verification in radiation therapy; however, they suffer from time‐dependent ion diffusion after irradiation, severely affecting their stability and reliability. In this work, a pullulan‐based amphiphilic molecule was synthesized, characterized, and self‐assembled into nanogels. Nanogel structures were embedded into gel dosimeters to reduce the diffusion rates, and radiation‐sensitive nanogel‐incorporated Fricke hydrogel nanocomposites were prepared successfully. The results demonstrated that the diffusion coefficient of improved dosimeters was reduced to 0.125 ± 0.001 mm2 h−1, while maintaining the high optical dose sensitivity (0.0410 ± 0.0004 Gy−1 cm−1). It provides a powerful tool toward the practical application of 3D dosimeters.

Review of nanomaterial advances for ionizing radiation dosimetry

“…Similar to this diffusion-free approach, modified cholesteryl pullulan nanogels were embedded into gel dosimeters, leading to a recent development of nanogel-incorporated 3D dosimeters. 151 The absorbance of the prepared nanogel-incorporated Fricke hydrogel nanocomposites at 585 nm was measured by spectrophotometer while ion diffusion curves were measured by magnetic resonance imaging (MRI). The results revealed that the diffusion coefficient of nanogel-incorporated dosimeter was reduced to 0.125 ± 0.001 mm 2 h −1 , but the high optical dose sensitivity remains constant (0.0410 ± 0.0004 Gy −1 cm −1 ).…”