Heat Transfer and Tissue Damage in Radiofrequency Ablation Therapy

Abstract

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.

Mathematical Modeling of Radiofrequency Ablation for Varicose Veins

“…If the tissue temperature becomes above about 313 K (40°C), then thermal damage can occur to tissues [ 13 , 15 , 25 ]. As blood velocity increases, perfusion of heat loss also increases due to the blood convection cooling effect.…”

“…Further, the temperatures were influenced by blood flow characteristics. We also assumed the heat transfer between the electrode and the tissue as well as the metabolic internal energy in the study to be neglected [ 15 ]. There was a problem as heat diffusion in the vessel wall was subjected to radiofrequency electrical energy, while heat loss occurred by blood flow and thermal convection.…”

“…At an electrode of the catheter, the heat ablates surrounding abnormal vein. If vessel wall temperature is raised above 323 K, cell damage cannot be recovered and coagulation around electrode can occur [ 7 , 15 ].…”