Investigation of Influence of Coaxial Antenna Slot Positioning on Thermal Efficiency in Microwave Ablation using COMSOL

Abstract

Continued development of the minimum invasive interventional technology in recent years has proven ablation therapy to be a safe and effective local treatment for cancers and has become increasingly important in the medicine. This is the reason for its preference for treating larger tumors than for radiofrequency ablation. The authors studied the influence of the geometry of the antenna used on the efficiency of the procedure to obtain a thermal lesion at the site of the tumor. The influence of the position of the coaxial antenna on the extent of the thermal lesion at the site of the tumor was investigated numerically by varying the distance from the position of the end of the antenna with COMSOL Multiphysics as the modeling tool. The coaxial antenna investigated has a 1.79 mm diameter range with a center conductor of 0.29 mm diameter and Tefzel ETFE as the material of the catheter. The power of the coaxial antenna was optimized with a slot spacing of 6 mm from the tip of the antenna. The total power dissipation density, and thus the degree of thermal damage generated during the process was found to depend on the position of the slots of the coaxial antenna.