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

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. [ABSTRACT FROM AUTHOR]