Chapter 15 - Dose enhancement effect in radiotherapy: adding gold nanoparticles to tumor in cancer treatment

Abstract

To date in cancer treatment, it is timely to conduct research on gold nanoparticle as a radiation dose enhancer and image contrast agent. Most studies focused on the dose enhancement resulting from adding gold nanoparticles to the tumors irradiated by the photon treatment beams. The relationship between the dose enhancement and different parameters of the gold nanoparticle, such as the size, shape, and concentration, were studied. Also, the dependence of dose enhancement on photon beam energies was investigated. In such studies, Monte Carlo simulations were used to predict the dose enhancement due to gold nanoparticle addition in water or human tissue. However, it was found that Monte Carlo results could not predict some radiobiological parameters, such as the radiation sensitization enhancement factor well, when compared to experimental data using the megavoltage photon beams. This may be due to neglecting the contribution of low-energy electron in the deoxyribonucleic acid damage. In this chapter, going through the background, development, and current status of gold nanoparticle-enhanced radiotherapy, we explore the rationale of dose enhancement due to gold nanoparticle addition and its applications in radiotherapy. We also study the physical and radiobiological effects on the cancer cell kill in the presence of gold nanoparticles.