Three-dimensional numerical study for hepatic tumor ablation using electric current and bioheat transfer

Abstract

In this research, the finite-element method (FEM) analysis has employed in the determination of distribution of tissue temperature during radiofrequency hepatic tumor ablation. We have investigated three dimensional (3D) thermal-electric FEM including a four-tine RF probe, hepatic tissue and an integrated model of a large blood vessel (10-mm diameter). We simulated our FEM analyzes under temperature-controlled (900C) 10-minutes ablation. Though the heated targeted cells are supposed to kill and the healthy surrounding tissues are supposed to save. Using the COMSOL Multiphysics software, we have numerically replicated the ablation process. The finite element method of Galerkin's weighted residual is employed to solve the governing system of equations (electric current and bioheat equations) with proper boundary conditions. The numerical simulation has been conducted various times from 0 to 600 s and electric voltage from 22 to 50 V with good convergence of the iterative scheme. In the term of temperature fields at different times, Iso-surfaces with temperatures of 500C at various times, Iso-surfaces at different temperatures, and the temperature distribution over time are displayed. Temperature distribution versus time at the tip of one of the electrodes arm at a fixed voltage and various voltages has displayed graphically. Results from the RF simulation indicate that temperature increases due to increasing time of ablation of tumor and electric voltage. The tumor cell has killed approximately at 500C with 22 V after 480 s heating. The proposed model could be a new tool for physicians for the efficient thermal insulation of tumors without any significant damage in healthy tissues.