<p>It becomes an important issue to enhance the efficacy of radiotherapy in the treatment of solid tumors. This study aims to study the effect of gold nanoparticles on the breast tumor to evaluate in radiation therapy treatment and researches. For this, photon, charged particles (electron, proton, helium, and carbon ions) and neutron interaction parameters of the breast tumor at different incident energies are investigated using PHITS, SRIM Monte Carlo, Phy-X/PSD, ESTAR, and PAGEX softwares. The mass attenuation coefficient, linear attenuation coefficient, effective atomic number, buildup factors, Kerma, mass stoping power, radiation yield, range, half value layer, and mean free path of the breast without and with the gold nanoparticles are calculated and for meaningful evaluation mass attenuation coefficients are compared with Phy-X/PSD results. This comparison shows a good agreement, with all calculated values deviating less than 1.5%. The addition of Au resulted in an enhancement for the radiation absorption ability of the samples. The results present that the radiation absorption effect of breast tumor with gold nanoparticles is higher than the case without gold nanoparticles and increase with increasing rates of the gold nanoparticles. This study represents the first comprehensive investigation of charged, uncharged particles, and photons, as well as different gold nanoparticles ratios, conducted concurrently. The findings may lead to the advancement of more effective radiotherapy processes for treatments. </p>