Electroporation of bone cancer: numerical evaluation of the electric field in treated tissues

Purpose - Electrochemotherapy (ECT) is an outstanding technique for treatment of tumor nodules which is currently used for treatment of skin metastases, and now it is being developed for treatment of internal organs such as, bone, liver, etc. In this work the authors' goal was finding a simple and proper needles configuration, allowing electroporation of whole cancer cell membranes, possibly minimizing direct cell death of healthy tissue. Design/methodology/approach - This work shows numerical analysis of the ECT of a deep-seated tumor, like in bone tissue of human limb. The tumor is excited by a sequence of square-wave electric pulses (5?kHz), inducing a 1,000?V/cm electric field through a suitable configuration of 30?mm long steel needle electrodes inserted in a part of limb long 20?cm. Treated element is numerically modeled in a very simplified 3D geometry. All materials are assumed as homogeneous, linear and isotropic mediums. Findings - Electrochemotherapy is based on the local application of short and intense electric pulses that transiently permeabilizes neoplastic cells membrane, thus allowing cytotoxicity increase of a chemotherapeutic drug, bleomycin, and reducing its dosage. The local field in target tissues depends on geometry and position of electrodes, that have to be placed according cancer shape and size, and excited by electric pulses of opportune amplitude. Current efforts are aimed to test whether electric pulses can be applied to bone through invasive needles without affecting the recovery of osteogenetic activity. Originality/value - The results of the simulation study can help to establish the appropriate geometric and electric setup for treatment of bone metastases in clinical ECT trials. This paper reports results from different needles configurations and show that a proper needle positioning allows complete electroporation of the whole tumor. Copyright © 2013 Emerald Group Publishing Limited. All rights reserved.