3d current density in tumors and surrounding healthy tissues generated by a system of straight electrode arrays

The knowledge of the adequate current density distribution to apply when using different electrode arrays in tumor tissue and the healthy surrounding tissue is one of the most significant challenges to improve the effectiveness of electrochemical treatment. This paper proposes a mathematical approach to obtain a three-dimensional analytical expression for the current density generated by multi-needle electrodes. Such array of electrodes can be allocated in an arbitrary shape and inserted anywhere in the tumor. Calculations of the electrical potential and electric current density distributions based on a three-dimensional model for different straight multi-needle electrode configurations are carried out by solving the Laplace equation. The results show that appropriate positioning, insertion depth and electrodes polarity are essential for tumor treatment with direct current and multiple needle electrodes, arranged in concentric circumferences, concentrate a higher electric current density in the tumor. This configuration of multiple straight needle electrodes inserted along the tumor improves the effectiveness of electrochemical treatment because the current density covers the entire volume of the tumor, unlike those configurations that are inserted in the tumor base and only partially cover its volume.