Monte Carlo Modeling of Coupled Radiative Heat Transfer in Laser Hyperthermia of Cancer with Embedded Gold Nanoshells
Photothermal therapy, Pennes bioheat equation, anisotropic radiation scattering, Henyey-Greenstein phase function, Mie theory
Photothermal Therapy uses radiation to increase tissue temperature and kill cancerous cells by hyperthermia. The main objective is to present a new approach for the simulation of heat transfer phenomena considering anisotropic scattering of radiation applied to nanoparticles assisted laser photothermal therapy. The Pennes’ bioheat equation coupled with the radiative transfer equation (RTE) accounted the balance of energy. To solve the RTE, current models use the diffuse theory which adds some shortcomings. Therefore a rigorous statistical Monte Carlo model has been proposed to increase accuracy and range of application. The Heney-Greenstein approximation and the Mie theory solved the scattering phase function for laser-tissue and laser-nanoparticles interactions, respectively. The study case consisted in a near-infrared (NIR) laser irradiating a very thin biological tissue composed of five layers, one of them with photon-absorbers silica-core gold nanoshells. Thus, a hybrid diffusion Monte Carlo model was presented and validated with published results obtained from discrete ordinates method. Further, it is planned to formulate more study cases, evaluate the non-diffusion Monte Carlo model, and compare results with data from the diffusion theory approach. Although the Monte Carlo method demands more computational time, it is expected to increase accuracy and scope of clinical applicability in relation to the diffusion models.