Abstract
Abstract
Today, with the advancement of nanotechnology, nanomaterials with high atomic numbers such as gold and titania nanoparticles can be specifically concentrated in tumor cells in various ways and benefited from the advantage of increasing the dose due to the proximity of these elements next to cancer cells as a radiation sensitizer. In this research, parameters such as radiation energy (in the range of kilo voltage), nanoparticles concentration, and tumor depth were investigated in the compressed breast phantom by using the MCNPX code to investigate the effect of radio sensitivity. The tumor in the form of a cube with sides of 0.5 cm was labeled with spherical nanoparticles of titania and gold with a radius of 70 nm with different concentrations. The results showed that exposure to the range of kilo voltage causes photoelectric absorption to occur with a high probability and a relatively large dose is delivered to the tumor. The energy that can cause the most damage to the tumor was obtained at 65 keV in the presence of gold nanoparticles and in the range of 40 to 45 keV in the presence of titania nanoparticles. Also, with increasing concentration the dose enhancement factor increases, but with increasing depth, for dose enhancement factor does not change.