Model for electron emission of high-Z radio-sensitizing nanoparticle irradiated by X-rays

TL;DR

This paper introduces a new probabilistic and Monte Carlo-based model to analyze electron emission from high-Z nanoparticles irradiated by X-rays, aiding cancer radiotherapy enhancement understanding.

Contribution

It combines analytical photon trajectory modeling with Monte Carlo electron cascade simulations, revealing an optimal nanoparticle radius for maximum electron emission.

Findings

Identifies a nanoparticle optimal radius for maximum electron emission.

Provides detailed insights into photon absorption and electron cascade depths.

Develops a comparative model for nanoparticle and planar surface emissions.

Abstract

In this paper we develop a new model for the electron emission of high-Z nanoparticle irradiated by X-rays. This study is motivated by the recent advances about the nanoparticle enhancement of cancer treatment by radiotherapy. Our original approach combines a pure probabilistic analytical model for the photon trajectories inside the nanoparticle and subsequent electron cascade trajectories based here on a Monte-Carlo simulation provided by the Livermore model implemented in Geant4. To compare the nanoparticle and the plane surface electron emissions, we also develop our model for a plane surface. Our model highlights and explains the existence of a nanoparticle optimal radius corresponding to a maximum of nanoparticle electron emission. It allows us to study precisely the nanoparticle photon absorption and electron cascade production depth in the nanoparticle.