Prog Med Phys.  2025 Mar;36(1):8-13. 10.14316/pmp.2025.36.1.8.

Monte Carlo Simulation for the Radiation Dose Enhancement Effect of Gold Nanoparticles in Brachytherapy

• Kim S

• KMID: 2566604
• DOI: http://doi.org/10.14316/pmp.2025.36.1.8

Abstract

Purpose
To assess the effect of gold nanoparticles (GNPs) on enhancing radiation doses in brachytherapy and evaluate their potential as radiosensitizers.
Methods
A Monte Carlo simulation was conducted to determine the radiation dose enhancement factor (DEF) of GNPs in brachytherapy using Iridium-192 (¹⁹²Ir) or Iodine-125 (¹²⁵I). The simulations compared the depth-dose curves of ¹⁹²Ir and ¹²⁵I in both water and tissue phantoms. A spherical tumor model with a radius of 3.5 cm surrounded by normal tissue was used for DEF calculation. The radioactive source was positioned at the center of the tumor and the DEF was calculated for GNP concentrations of 7, 18, and 30 mg/g present only in the tumor tissue.
Results
The differences in depth doses between the water and tissue phantoms were more noticeable for ¹⁹²Ir than for ¹²⁵I. For ¹⁹²Ir, the DEF of the GNPs ranged from 1.6 to 2.8, depending on the concentration of GNP. For ¹²⁵I, the DEF was less than 1.
Conclusions
GNPs were confirmed to enhance the radiation dose in brachytherapy when using 192 Ir.

Keyword

Gold; Nanoparticles; Radiotherapy