Solution to the bioheat equation for hyperthermia with La_1−xAg_yMnO_3-δnanoparticles: The effect of temperature autostabilization

Abstract

This work aimed to analyze the possibility and performance of the temperature controlled hyperthermia based on AC heating of magnetic nanoparticles with low Curie temperature. Temperature dependence of dynamic magnetic susceptibility has been studied experimentally on fine powders of La(0.8)Ag(0.15)MnO(2.95) in the frequency range of 0.5-2.0 MHz. Critical drop of the AC magnetic losses was found in the vicinity of the Curie point, T(C) = 42 degrees C. The obtained data was used in the numerical analysis of the bioheat equations under typical conditions of the hyperthermia treatment. The mathematical model includes a spherical tumor containing magnetic particles and surrounded by concentric healthy tissue, with account made for the blood perfusion. The calculations performed for various AC power, tumor sizes and doping geometries predict effective autostabilization of the temperature at T congruent with T(C) inside the tumor and steep temperature profile at the interface with the healthy tissue.

Current devices for high-performance whole-body hyperthermia therapy

“…For example, injection of magnetic fluids and nanoparticles was once thought to be of high efficiency in localized tumor ablation [131][132][133][134]. Nevertheless, Babincov et al introduced subdomain dextran-stabilized magnetite particles to absorb heat in the external RF field [135,136].…”

Critical RF losses in fine particles of La1−xAgyMnO3+δ: Prospects for temperature-controlled hyperthermia

“…Because of strong temperature dependence of w 00 , the SAR values are calculated both for the ambient temperature and for the temperatures T max corresponding to the maximum values of w 00 . The results looks rather acceptable for applications, especially for the A samples; the detailed numerical calculations for biomedical objects are published elsewhere [25].…”

“…1(a)-(c) with the solid curves (the corresponding expressions are not shown for short); details are available in Ref. [25]. Typical transient and steady-state solutions of the heat equation are presented in Figs.…”

State of Art on Bioimaging by Nanoparticles in Hyperthermia and Thermometry: Visualization of Tissue Protein Targeting

“…Most of available hyperthermia therapy, both systemic and targeted, has been reported as adjunctive therapy to support radiotherapy or chemotherapy [63]. Several reasons of tissue damage are reported as to the limited success of hyperthermia [64][65][66]; a few have been mentioned in this review and shown in Table 1.…”