Numerical modeling to calculate thermal lesion formation using internally-cooled electrodes during radiofrequency ablation of liver tumors

Abstract

Radio-frequency ablation (RFA) heat treatment is a popular “minimally invasive” treatment method for both primary and metastatic liver tumors, and the heat treatment is studied by numerical calculation. Most of numerical modeling in radio-frequency ablation use commercial finite element methods package. The present paper describes the model used finite difference methods to simulate RFA with internally-cooled electrode, and large blood vessels cooling simultaneously. A finite difference model is used to solve all partial differential equations (PDEs) for a simple three dimensional (3-D) cubic geometry model. Maximum tissue temperature is used as a critical index for reaching thermal lesion during RFA. Cylindrical RF cool-tip electrode is internally cooled at constant water temperature. The use of series and parallel thermal resistances of composite materials are presented in the model. Results show consistency with experimental results.