Modeling hyperthermia-based prostate cancer treatment in the presence of core-shell nanoparticles and large blood vessels under different ultrasound sonication patterns

Abstract

The use of nanoparticles, as enhancing agents to transform ultrasound energy into heat for tumor destruction, is a promising approach to improve the efficacy of thermal-based cancer therapies. This study aimed to evaluate the effectiveness of core-shell type nanoparticles and the heat loss due to blood flow in large vessels under different patterns of ultrasound sonication in the hyperthermia-based treatment of the prostate cancer. For this purpose, the ultrasound attenuation coefficient in the prostate tumor embedded with nanoparticles was calculated using a scattering theory that was developed for core-shell type particles. Using the attenuation coefficient and the linear pressure wave equation, the acoustic power dissipated per unit volume of a three-dimensional (3D) model of the prostate tumor and its surrounding tissues was calculated. By simultaneous solving the bioheat, the convective energy, the continuity, the Navier-Stokes, and the thermal dose equations, the temperature and thermal dose distribution were computed in the model. The attenuation coefficient of the tumor showed a decreasing trend with increasing the thickness of the silica shell coating the magnetite or titania core. The capability of nanoparticles to enhance heat production in the medium was directly, and the blood flow heat loss was inversely, related to the degree of focus of the ultrasound beam. The thermal response of the tumor was influenced by its size and geometry, as well as the acoustic intensity. Titania nanoparticles were more efficient than the magnetite nanoparticles in ultrasound attenuation and heat production in the medium. Our findings can be useful in understanding the factors affecting the hyperthermia-based treatment of the prostate cancer using a combination of ultrasound and nanoparticles.