Role of Photo- and Cascade Electrons in Photon Activation Therapy using High-Z Radiosensitizers

Abstract

Emission of electrons and photons during the cascade decay of vacancies in the electron shells of the Ag, Gd and Pt atoms are simulated by straightforward construction and analysis of the cascade decay trees. The energies reemitted with cascade photons, cascade electrons and photoelectrons after photoionization of Ag, Gd and Pt atoms in the 0.1­100 keV incident photon energy range are calculated. It is shown that the cascade electrons and photoelectrons are the most effective local energy depositors when the high-Z atoms are used as radiosensitizers in photon activation therapy