Non-thermal membrane effects of electromagnetic fields and therapeutic applications in oncology

" Our overview is intended to show that non-thermal effects exist in the RF range of 10−30 MHz that can be exploited for therapeutic purposes as a further development of conventional hyperthermia. Microscopic hot spots, which are often cited as an explanation for alleged non-thermal effects, were discussed in detail and could largely be excluded both in the clinical studies discussed and in the preclinical experiments (Section 5.1). Instead, we presented possible mechanisms at ion channels for non-thermal effects of sinusoidal RF (Section 5.2). The data suggest that additional AM with selected (tumor-specific) modulation frequencies might enhance the antiproliferative effects of sinusoidal RF (Sections 3.3 and 4.3). We presented membrane resonances as a possible explanation for such frequency-dependent behavior and could correlate the observed modulation frequencies (hertz to kilohertz) with elastic membrane properties that are characteristic for tumor cells (Section 5.3)." {Credits 1}

" In our model, transmembrane ion channels function like RF rectifiers and low-pass filters. cRF-HT induces ion fluxes and AM-RF-HT additionally promotes membrane vibrations at specific resonance frequencies, which explains the non-thermal antiproliferative membrane effects via ion disequilibrium (especially of Ca2+) and/or resonances causing membrane depolarization, the opening of certain (especially Ca2+) channels, or even hole formation. AM-RF-HT may be tumor-specific owing to cancer-specific ion channels and because, with increasing malignancy, membrane elasticity parameters may differ from that in normal tissues." {Credits 1}

{Credits 1} 🎪 Peter Wust, Ulrike Stein & Pirus Ghadjar (2021) Non-thermal membrane effects of electromagnetic fields and therapeutic applications in oncology, International Journal of Hyperthermia, 38:1, 715-731, DOI: 10.1080/02656736.2021.1914354. © 2021 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License.