Electrochemical treatment of tumours: a simplified mathematical model

Electrochemical treatment of tumours implies that tumour tissue is treated with a direct current. During electrolysis, electrical energy is converted to chemical energy through electrochemical reactions at the electrodes. The anode is preferably placed in the tumour and the cathode in a blood vessel or in fresh surrounding tissue. The main electrochemical reactions are chl orine and oxygen evolution, at the anode? if platinum is used. Hydrogen evo lution takes place at the cathode. The aim of this paper is to show how mat hematical modelling can be used as a tool for defining and optimising the o perating conditions of electrochemical treatment (ET) of tumours. A simplif ied mathematical model is presented for direct current treatment of tumours , focusing on tissue surrounding a spherical platinum anode. The tissue is treated as an aqueous solution of sodium chloride and only the major electr ochemical reactions are considered. The model is based on transport equatio ns of ionic species in dilute solutions. Kinetic expressions for the electr ochemical reactions, at the anode surface, are introduced. Inputs to the mo del are the applied current density, and sizes of the anode and electrolyte domain. Concentration profiles of the ionic species and potential distribu tion, as a function of time. are calculated. In addition, current yields of the anode reactions are obtained from the model. (C) 1999 Elsevier Science S.A. All rights reserved.