Microwave Ablation Trocar Operated at Dual Tine Dual-Frequency: A Numerical Analysis

Abstract

Microwave ablation (MWA) is a minimally invasive thermal ablation technique that has the advantages of obtaining high intratumoral temperatures, less treatment time and large ablation region as compared to other thermal ablation techniques. The ablation region obtained during MWA procedure mainly depends on the design and type of the trocar being used. The trocar plays an essential role in the MWA system by governing the energy distribution during tissue ablation. In this study, a novel MWA trocar design has been considered to achieve concentrated ablation region along the tumor's spatial distribution. A dual tine trocar with each tine supplied with energy at different frequencies (2.45 GHz and 6 GHz) has been considered for tumor ablation. Commercially available Finite Element based software has been used (COMSOL-Multiphysics) to analyze the extent of ablation zone. Coupled bioheat and electromagnetic physics interfaces have been utilized. Results showed that the proposed trocar with tines operating at 6 GHz on both the tines leads to a large ablation region (3 cm in diameter) with spherical in shape. Irregularly shaped ablation region can also be achieved by this trocar with tines operating at different frequencies. The minimum time required for complete tumor ablation by the trocar operated at 6 GHz is 4 minutes, followed by 6 minutes for the trocar operated at 2.45 GHz. The proposed trocar can become a part of a better treatment planning system (TPS) based on tumor shape, nearby blood vessel presence, and the trocar's precise insertion.

Effect of high blood flow on heat distribution and ablation zone during microwave ablation‐numerical approach

“…14 Numerous variables, including antenna design, input power, frequency range, tumor size, location, porosity, vascular perfusion, and presence of blood vessels, affect the outcome of thermal ablation. [15][16][17][18][19][20][21] The influence of antenna design, input power, and frequency range on the ablation zone is well studied in the literature. 16,17,[22][23][24][25][26] The 915 MHz or 2.45 GHz frequency range where the majority of the MWA system was operational.…”

Safety and efficacy of intracavitary microwave ablation in hepatic gland tumours: Numerical and in vitro studies

“…The use of high frequency in MWA technique increases flexibility in probe design and in developing better treatment planning procedures. 20,21 As per the guidance from the Industrial, Scientific and Medical (ISM) Radio Band guidelines, the frequencies of 2.5, 5.89 and 24 GHz, can be used in medical applications. 22 The present study has been designed to assess the ablation region obtained using multiple MWA trocars both numerically and experimentally.…”