Optimizing magnetic hyperthermia respecting field safety conditions

Abstract

A precise evaluation of magnetic nanoparticle heating under AC fields is essential to optimize hyperthermia treatments within physiologically safe limits. Standard models often rely on the uniaxial anisotropy approximation, assuming shape effects to dominate. However, we show that this assumption fails at low field amplitudes relevant to clinical conditions. Using computational simulations based on the Landau-Lifschitz-Gilbert equation implemented via OOMMF, we demonstrate that intrinsic magnetocrystalline anisotropy significantly influences the specific loss power (SLP), and that even minor deviations from the spherical shape can strongly affect heating efficiency. We will compare our results under the Thiesen-Jordan criterion to those obtained using the more commonly adopted Brezovich criterion, highlighting the importance of including intrinsic anisotropy, as well as controlling NP size and ensemble aspect ratio variability, when modeling hyperthermia performance under realistic safety constraints.