Modeling Electrical and Thermal Conductivities of Biological Tissue in Radiofrequency Ablation

Radiofrequency ablation (RFA) is a minimally invasive technique used to treat some kinds of cancer. Theoretical models can provide information about the biophysics of RFA quickly and cheaply, but their realism is very important. A great influential factor in this realism is the use of mathematical functions to model the temperature-dependence of tissue thermal (k) and electrical (s) conductivities. The aim of this work is to review the mathematical functions employed to model temperature-dependence of k and s in previous RFA computer modeling studies and to assess how these different functions affect lesion dimension evolution. We use a model of RF hepatic ablation in which both conductivities are modeled with different mathematical functions and compare the lesion sizes obtained in every case. We solve numerically the problem using COMSOL Multiphysics. Results suggest that the different functions to model the temperature dependence of k and s do not significantly affect the computed lesion diameter.