Measurement of absorbed dose in normoxic polymer gel and study of gold nanoparticles configuration effects

Radiotherapy includes all methods that can deliver a particular amount of ionizing radiation to malignant tissues, assuming that minimal damage hurts healthy tissues. We are looking for a valuable and reliable method to measure absorbed dose and the ability to measure the distribution of absorbed dose in three dimensions which nowadays is one of the three-dimensional dosimetry methods in using radiation-sensitive polymer gels. The purpose of the present study was to calculate the amount of increase of absorbed dose in the presence of gold nanoparticles and to investigate the type of gold nanoparticles arrangement (uniformly and shells) in the polymer gel of normoxic. In this study from both experimental and simulation approaches, a dosimeter of a normoxic polymer type gel was used to measure the amount of absorbed dose changes of Gamma rays in the presence of gold nanoparticles irradiated with   Iridium-192 source beams. Thermolominans dosimetry reading system was used to read steps of dose value and then    MCNPX computational code was simulated by using Monte Carlo method. The results were compared and investigated by experimental experiments. In the presence of gold nanoparticles uniformly distributed in polymer gel, with 0.1mM to 1.5mM, the maximum absorbed dose was 0.24% and in shell state it was 20%. The result and investigation of both experimental and simulation studies showed that the optimum density of gold nanoparticles in the normoxic polymer gel is 1.5mM, which can be used for clinical trials.