Investigation of physical dose enhancement in core-shell magnetic gold nanoparticles with TOPAS simulation

TL;DR

This study uses TOPAS simulations to analyze how magnetic gold nanoparticles enhance radiation dose in cancer therapy, revealing their properties and the influence of magnetic fields in different irradiation scenarios.

Contribution

First simulation-based analysis of magnetic gold nanoparticles' dose enhancement and magnetic field effects in radiotherapy and brachytherapy.

Findings

Magnetic gold nanoparticles have a 16.7% lower dose enhancement factor than gold nanoparticles with monoenergetic photons.

Magnetic fields do not negatively affect radiosensitization.

First investigation of magnetic gold nanoparticles in clinical brachytherapy sources.

Abstract

The application of metal nanoparticles as sensitization materials is a common strategy that is used to study dose enhancement in radiotherapy. Recent in vitro tests have revealed that magnetic gold nanoparticles can be used in cancer therapy under a magnetic field to enhance the synergistic efficiency in radiotherapy and photothermal therapy. However, magnetic gold nanoparticles have rarely been studied as sensitization materials. In this study, we obtained further results of the sensitization properties of magnetic gold nanoparticles using the Monte Carlo method TOPAS and TOPAS-nBio. We analyzed the properties of magnetic gold nanoparticles in monoenergetic photons and brachytherapy, and we investigated whether the magnetic field contributes to the sensitization process. Our results demonstrated that the dose enhancement factor of the magnetic gold nanoparticles was 16.7% lower than that of gold nanoparticles in a single particle irradiated by monoenergetic photons. In the cell model, the difference was less than 8.1% in the cytoplasm. We revealed that the magnetic field has no detrimental effect on radiosensitization. Moreover, the sensitization properties of magnetic gold nanoparticles in a clinical brachytherapy source have been revealed for the first time.