Fricke gel dosimeter prepared by irradiation induced crosslinking method

Abstract Background: Radiotherapy is one of the main methods for treating cancer, and its efficiency depends heavily on accurate dose verification. Fricke gel dosimeters are fabricated from ferrous sulfate and polymer gel upon irradiation, with ferrous as a function of the absorbed radiation dose. Purpose: This study aims to explore the one-step irradiation induced crosslinking method to fabricate the Fricke gel dosimeter with polyacrylic acid as the frame, and study the structure and properties of the Fricke gel. Methods: The chemical structure and stability of gel is measured by Fourier transform infrared spectrometer (FTIR), X-ray diffractometer (XRD), Thermo-gravimetric analyser (TGA) and water absorption analyser. The diffusion behavior of Fe²⁺ in gel is measured by molecular dynamics simulation. And the dose response ability of Fricke gel dosimeter is analyzed by spectrophotometry. Results: Experimental results show that the coordination bonds between the ferrous ions and-COOH groups are proven by FTIR analysis, and the result of molecular dynamics simulation reveals that PAAc(Polyacrylic acid) chains can reduce the diffusion of ferrous ions. Conclusion: The dose response standard curves indicated Fricke gel dosimeter can be applied to dose verification in radiotherapy. In addition, the existence of xylenol orange (XO) can improve dose sensitivity of Fricke gel dosimeter. (authors)