Estimation of SLP/ILP parameters during hyperthermia with mobilized and immobilized MNPs

What is it about?

Purpose: Magnetic hyperthermia is a medical procedure for treating cancerous tumors that are medically unsuitable for resection or other treatments. It involves injecting magnetic nanoparticles (MNPs) into the cancerous tissue and applying an external alternating magnetic field (AMF) to induce heat in the target tissue. Under the influence of an AMF at radiofrequency range, eddy currents are generated, and MNPs are heated in the tumor's volume, resulting in apoptosis or necrosis. The purpose of this study is to numerically analyze the power losses generated by MNPs, such as specific loss power (SLP) and intrinsic loss power (ILP), as well as the temperature distribution during magnetic hyperthermia concerning a tumor placed in an anatomical model of the female breast. Methods: The AMF source was a helical induction coil with an excitation current surrounding the female breast phantom. Numerical analysis was based on the solving the Helmholtz equation for the magnetic vector potential coupled with the modified Pennes equation, using the finite element method (FEM). The numerical model under consideration included the power dissipation generated by MNPs based on the linear response theory, proposed by Rosensweig, and the Joule heating generated by eddy currents. Results: The authors compared the effects of MNPs concentrations on the outcome thermal profiles of irregularly shaped breast tumors. Additionally, tumor temperature profiles and SLP/ILP parameters were determined in the case of mobilized and immobilized MNPs. Conclusions: MNPs immobilization within the tumor microenvironment significantly diminishes magnetic losses, with a corresponding reduction of approximately 30% in SLP/ILP parameter values.

Featured Image

Why is it important?

Key words: magnetic hyperthermia, breast cancer, linear response theory, specific loss power, intrinsic loss power, mobilized and immobilized magnetic nanoparticles

Perspectives