Chapter 14 - Hadrontherapy enhanced by combination with heavy atoms: Role of Auger effect in nanoparticles

Abstract

This chapter is dedicated to the possibility of augmenting the radiobiological effects when irradiated tissues are loaded with high-Z atoms contained in molecules or nanoparticles by fast atomic ions. A preliminary quantitative study of DNA break induction by monochromatic photons tuned to the resonant photoabsorption energy of LIII shell of platinum suggests that secondary electrons emitted by the incident ionizing particles can trigger the Auger effect in the high-Z atom by inelastic collision. Imaging by nano secondary ion mass spectrometry experiments of cells loaded with platinum salt has revealed that the high-Z atoms need not be located in the nucleus to increase the cell death rate. This finding opens the possibility of using nanoparticles made of high-Z atoms in combination with atomic ion irradiation to augment the cell death rate. Experiments made with HeLa and U87 glioblastoma cell lines, in combination with platinum or gold salt, and also nanoparticles, show a neat enhancement of the cancerous cell line death rate.