Heat Transfer and Tissue Damage in Radiofrequency Ablation Therapy

Heat transfer in radiofrequency ablation therapy of liver tumors is discussed. Temporal and spatial temperature changes around a single needle and multi-prong ablation probes in monopolar and bipolar configurations based on a two-dimensional finite elements method are presented. The temperature changes and related heat transfer in the tissue model help to visualize the shape and size of the ablated region. The visualization of the tissue temperatures and their progression could be useful in clinical applications of ablation therapy. Finite-element based numerical simulation, while providing useful visualizations of the temperature changes in and around the tumor, underestimates the lesion size. The perfusion in the tissue and the possible presence of large blood vessels in or near the ablated domain, and the temperature dependency of the thermal and electrical properties of the tissue are significant complicating factors in modeling and clinical applications.