Modeling an Injection Profile of Nanoparticles to Optimize Tumor Treatment Time with Magnetic Hyperthermia

Eagle, Sonja; Wadsworth, Samantha; Wnorowski, Alexa

Modeling an Injection Profile of Nanoparticles to Optimize Tumor Treatment Time with Magnetic Hyperthermia

Abstract

Hyperthermia treatment to destroy cancerous tissue is a highly effective treatment strategy for malignant tumors. The goal of hyperthermia treatment is to raise the tumor temperature high enough to kill cancerous cells while minimizing damage to normal surrounding tissue. This project focuses on optimizing the treatment time using iron oxide magnetic nanoparticles (MNPs) to induce hyperthermia in cancerous tumors. In this treatment, the MNPs are injected into the center of the tumor, and their movement through the tissue is modeled using pressure-driven Darcy flow and simple mass diffusion. The MNPs are activated by a magnetic coil surrounding the tissue that produces an AC magnetic field, and heat is produced due to friction between the nanoparticles as they change orientation with the alternating current. This friction is sufficient to produce hyperthermia. Because of the many parameters that can be changed in hyperthermia treatments, computational modeling of this process could provide a more efficient way of determining optimal treatments. However, most previous models do not model the injection and diffusion of nanoparticles, but rather have an exponential decay power equation as a heat source at the site of injection. To create a more accurate model, the injection process and mass diffusion of the nanoparticles can be modeled and coupled to the heating process through an electromagnetic heat source term. In this COMSOL model, a tumor was approximated as a sphere surrounded by a sphere of normal tissue. Nanoparticle heat production within the tumor during exposure to a magnetic field is proportional to the nanoparticle concentration, which can be determined from the diffusion model including Darcy fluid flow. The transient temperature profile of the tissue was then monitored to observe the extent of damage to both the tumor tissue and surrounding healthy tissue. Treatment time was then optimized for a specific initial nanoparticle fluid concentration and injection velocity. For a tumor with properties of a common liver tumor, nanoparticles with a concentration of 78600 g/m3 were injected at a flow rate of 20 μL/min for fifteen minutes and allowed to diffuse for 24 hours. Under these conditions, optimal heating time was determined to be 11.5 minutes. In the future, this model could be adjusted based on tumor size, geometry, and specific parameters such as density, as well as various types of nanoparticles, and used in a clinical setting to determine optimal treatment prior to beginning the hyperthermia treatment.

Date Issued

2015-05-19

Keywords

Computer-Aided Engineering; Biomedical Processes

Types

term paper