Investigation of the use of novel ceramic oxide nanoparticles to improve the clinical outcome of radiation therapies

The use of nanoparticles (NPs) to enhance the efficacy of different radiotherapy techniques is investigated by means of Monte Carlo simulation in this PhD project. The dose enhancement of radiation therapy in order to increase the ratio of tumour cell killing to normal tissue damage is an area of much interest in the medical physics research community. With increasing spatial and energy modulation of radiotherapy beams, the dose to tumour tissue can be intensified whilst sparing neighbouring healthy tissue. The advancement in capabilities of beam modulation does however have limitations and this is why methods of dose escalation preferential to cancerous tumour cells are an interesting area of current research. Nanoparticle dose enhancement shows great potential for the optimisation of radiation therapy modalities which is demonstrated in simulations and by experimental evidence. In order for NP dose enhancement to be applied in a clinical radiotherapy setting, a thorough fundamental study of the mechanism of dose enhancement is required. The mechanism of physical dose enhancement of radiation therapy modalities, including conventional X-ray and proton therapy, is studied by means of Geant4 Monte Carlo simulations presented in this thesis. This PhD thesis presents simulation studies on both micro- and nano-scales calculating dose enhancement from novel ceramic oxide NPs, compared to widely studied, dose enhancing gold NPs. Customised Geant4 simulations have been developed in this project to model dose enhancement in water volumes in proximity to various NPs, approximating the conditions of radiation dose enhancement in cells or tissue. The effect of size, shape, concentration and distribution of the NPs within a cell volume is investigated by means of Geant4 simulations.