Optimal dose-response relationship in electrolytic ablation of tumors with a one-probe-two-electrode device

• Electrolysis products have a major role in pulsed electric field treatment of tumors
• The coulomb (charge) dosage is a reliable parameter in tumor electrolytic ablation
• The necrotized tumor volume scales with dosage to the power of 1.4

Electrolytic ablation (EA), a medical treatment used in solid tumor ablation due to its minimum side effects and low cost, consists in the passage of a low constant electric current through two or more electrodes inserted in the tissue thus inducing pH fronts that produce tumor necrosis. Combined with a recently introduced one-probe two electrode device (OPTED) this procedure results in a minimally invasive treatment. Despite its success, EA has drawbacks such as the difficulties in determining the optimum dose-response relationship between the applied current, treatment time and necrotized tumor volume (NTV) and choosing a reliable dose parameter. In this work, a theoretical model is introduced describing the EA/OPTED as an electrolytic process and the underlying electrochemical reactions through the Nernst-Planck equations for ion transport. Model results show that the coulomb dosage is a reliable dose parameter and predicts an optimal dose-response relationship for a given tumor size subjected to an EA/OPTED, considering the optimum as the minimum coulomb dosage necessary to achieve total tumor destruction while minimizing healthy tissue damage. Moreover, it predicts a nonlinear relationship between coulomb dosage and NTV, dosage and NTV scaling as Q1.4. Consequently, these results could have a significant impact on dose planning methodology aimed at improving the effectiveness of the electrolytic ablation.

Experiments and simulations show that applying an electric current to tumor tissues with electrodes in close vicinity generates an spherical wave of pH fronts, and that evolution of induced necrotic volume is a function of coulomb dosage transferred.Figure optionsDownload as PowerPoint slide