Numerical analysis of heat transfer and tissue deformation in liver cancer during microwave ablation: A comparison of bioheat and porous media models

Abstract

This study presents a numerical comparison of microwave ablation using the Pennes bioheat and porous media models in a deformed liver cancer geometry. A single slot coaxial antenna operating at 2.45 GHz with a power of 10 W for 10 min was simulated using the finite element method, incorporating electromagnetic wave propagation, heat transfer, and tissue deformation. Validation against published experimental data and a mesh independence test confirmed the accuracy of the model. Results indicate up to a 6.7 % higher specific absorption rate in the porous media approach, contributing to a temperature difference of approximately 10–13 % at 10 min compared to the Pennes model. Peak von Mises stress increased by more than 2 Pa in tumor regions, and necrosis progression differed between the models. While both models predicted complete tumor cell death, the Pennes bioheat approach consistently reached thresholds sooner in both tumor and adjacent healthy tissue. These findings highlight the role of tissue porosity and convection in heat transport and deformation, demonstrating the porous media model's improved predictive capability for longer ablation durations and its potential for optimizing treatment protocols.