Thermal Considerations with Tissue Electroporation

Abstract

Electroporation is an energy-directed therapeutic that relies on the application of pulsed electric fields to increase the transmembrane potential of a cell above a critical value, destabilizing the lipid bilayer of the cellular membrane and increasing cell tissue permeability. For years, researchers have used this phenomenon to assist the transport of macromolecules that typically are unable to penetrate the cell membrane with the intent of avoiding cell necrosis or irreversible electropo-ration. More recently, however, irreversible electroporation is proven to be a successful option for the treatment of cancer. More specifically, the proper tuning of pulse parameters has allowed for a nonthermally damaging targeted treatment of unresectable tumors. Pretreatment planning is implemented to moderate the associated thermal effects with the electroporation of biological tissue. However, the overall size and volume of the ablation is a function of the electrode geometry, electrode spacing, voltage amplitude, pulse frequency, and pulse repetition. Many researchers are motivated to maintain tissue temperature below a thermally damaging threshold while expanding the range of treatment and increasing ablation dimensions. Thermal mitigation strategies, including the installation of active cooling channels and phase change materials within electrodes, have the potential to allow the delivery of more energy to the tissue at a thermally safe temperature, ultimately resulting in larger ablation volumes.