Influence of Electrodes on Electric Field Distribution for Effective Electrochemotherapy

Abstract

Electro oration is the application of electrical pulses for enhanced drug delivery. When used for delivering chemo drugs, it is called electrochemotherapy (ECT). For inoperable and chemo- and radio-resistant tumors, we need an alternative technique and ECT is a viable option as evidenced by the treatment of thousands of patients, effectively. The efficiency of the ECT depends on the voltage (electric field) magnitude, pulse duration, number of pulses, the drug molecule to be delivered and the electrode geometry and size. It is of practical interest to study the effect of material on the efficacy of the therapy. Towards this, in this research, we investigated the influence of electric field distribution due to different electrode materials. For this purpose, both platinum and surgical steel needle array electrodes were used. Surgical steel is the most commonly used material for electro chemotherapy applications. These needle electrodes are of both hexagonal and pentagonal configurations with a central electrode in each. ANSYS, the industry standard software that used finite element method is used to study the electric field distribution, of both healthy tissue and tumor tissue using these two electrode configurations and the two different materials. Both unipolar and bipolar voltages were studied. The results indicate that the electric field distribution, both in magnitude and pattern is similar for both electrodes, for both configurations and materials, which is desired from the clinical aspect. The electric field intensities for the hexagonal and pentagonal needle electrodes were 1280V/cm and 1180V/cm respectively in the case of tumor tissue (correlating well with the desired level of 1200V/cm). They were 835V/cm and 843V/cm for these electrodes in the case of healthy tissues. The values were same in the case of bipotential voltages too.