Computational evaluation of amplitude modulation for enhanced magnetic nanoparticle hyperthermia

Biomed Tech (Berl). 2015 Oct;60(5):491-504. doi: 10.1515/bmt-2015-0046.

Abstract

Magnetic nanoparticles (MNPs) can interact with alternating magnetic fields (AMFs) to deposit localized energy for hyperthermia treatment of cancer. Hyperthermia is useful in the context of multimodality treatments with radiation or chemotherapy to enhance disease control without increased toxicity. The unique attributes of heat deposition and transfer with MNPs have generated considerable attention and have been the focus of extensive investigations to elucidate mechanisms and optimize performance. Three-dimensional (3D) simulations are often conducted with the finite element method (FEM) using the Pennes' bioheat equation. In the current study, the Pennes' equation was modified to include a thermal damage-dependent perfusion profile to improve model predictions with respect to known physiological responses to tissue heating. A normal distribution of MNPs in a model liver tumor was combined with empirical nanoparticle heating data to calculate tumor temperature distributions and resulting survival fraction of cancer cells. In addition, calculated spatiotemporal temperature changes were compared among magnetic field amplitude modulations of a base 150-kHz sinusoidal waveform, specifically, no modulation, sinusoidal, rectangular, and triangular modulation. Complex relationships were observed between nanoparticle heating and cancer tissue damage when amplitude modulation and damage-related perfusion profiles were varied. These results are tantalizing and motivate further exploration of amplitude modulation as a means to enhance efficiency of and overcome technical challenges associated with magnetic nanoparticle hyperthermia (MNH).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Temperature / radiation effects*
  • Computer Simulation
  • Dose-Response Relationship, Radiation
  • Electromagnetic Fields
  • Humans
  • Hyperthermia, Induced / methods*
  • Magnetic Field Therapy / methods
  • Magnetite Nanoparticles / radiation effects*
  • Magnetite Nanoparticles / therapeutic use*
  • Models, Biological
  • Neoplasms / physiopathology*
  • Neoplasms / therapy*
  • Radiation Dosage

Substances

  • Magnetite Nanoparticles