An optimization study considering MNP temporal evolution improves therapeutic efficacy in hyperthermia treatment

Abstract

This work investigates optimal strategies for achieving the most effective tumor ablation outcomes in magnetic hyperthermia by incorporating the thermal exposure time, magnetic nanoparticle (MNP) dose, injection sites, and waiting time before alternating magnetic field (AMF) application. The optimization framework highlights the significance of thermal exposure time, as this treatment duration substantially influences the temporary distribution of the heat source, i.e., MNPs, and consequently affects the thermal dose for efficacy evaluation. Multi-site MNP injections are involved in both circular and elliptical tumor configurations, and a transversal blood vessel introduces asymmetric cooling effects. This optimization framework can achieve efficient convergence, demonstrating its effectiveness in identifying the optimal strategy. Without the influence of the blood vessel, optimal injections exhibit a centrosymmetric distribution in the circular tumor model; comparatively, a linear distribution along the major axis with approximately halved treatment duration is observed in the elliptical model. When the blood vessel is nearby, the notable asymmetric cooling effects complicate treatment, where the random search method is more effective. Increasing the tumor–vessel distance enhances tumor ablation, reduces MNP dosage and treatment time, and decreases the average injection site deviation; however, the impact becomes marginal at larger distances. This optimization study facilitates the efficacy of practical treatment.