Polymer gels impregnated with gold nanoparticles implemented for measurements of radiation dose enhancement in synchrotron and conventional radiotherapy type beams

Normoxic type polyacrylamide gel (nPAG) dosimeters are established for dose quantification in three-dimensions for radiotherapy and hence represent an adequate dosimeter for quantification of the dose variation due to the existence of the gold nanoparticles (AuNPs) in the target during irradiation. This work compared the degree of polymerisation in gel doped with nanoparticles (nPAG-AuNP) with control gel samples when irradiated by various sources. Samples were irradiated with a synchrotron radiation source of mean energy 125 keV, 80 kV X-ray beams from superficial therapy machine (SXRT), 6 MV X-rays and 6 MeV electron beams from linear accelerator. Analysis of the dose-response relation was used to determine a dose enhancement factor (DEF) of 1.76 ± 0.34 and 1.64 ± 0.44 obtained for samples irradiated with kilovoltage X-rays energy from synchrotron source and SXRT respectively. Similarly, including AuNPs in gel results in a DEF of approximately 1.37 ± 0.35 when irradiated by an electron beam and 1.14 ± 0.28 for high energy X-ray beams. The results demonstrate the use of AuNPs embedded in polymer gels for measuring the enhancement of radiation caused by metallic nanoparticles.