Evaluation of Gold Nanoparticles Radio Sensitization Effect in Radiation Therapy of Cancer

In radiotherapy, ionizing radiations such as X-rays, gamma, high-energy particles are widely using for the treatment of cancer tumors in solid form. Unfortunately, ionizing radiations are not capable of detecting cancer cells from healthy cells. Therefore, healthy tissue hurts due to radiotherapy for eradicating the cancer cells. Improved radiotherapy outcomes can be achieved by employing ion beams due to the characteristic energy deposition curve which culminates in a localized, high radiation dose. Some studies indicated energy dependency of dose enhancement effect, and the others have studied the gold nanoparticle (GNP) size effect in association with photon energy. However, in some aspects of GNP-based radiotherapy the results of recent studies do not seem very conclusive in spite of relative agreement on the basic physical interaction of photoelectric between GNPs and low energy photons. The purpose of the current paper was to assess the current status of gold nanoparticles applications in radiation therapy. In this review, we summarized the mechanisms of action of radiation therapy with photons and ions in the presence and absence of nanoparticles, as well as the influence of some of the core and coating design parameters of nanoparticles on their radio sensitization capabilities.