Microwave hyperthermia ablation of hepatic cancerous tumors using different coaxial antenna designs: A numerical analysis

Microwave Hyperthermia Ablation (MWHA) is a recent thermal ablation method for managing Hepatocellular Carcinoma. The ablation’s size and effectiveness rely on the medical applicator design (antenna) and energy transfer efficiency. In this study, a comprehensive numerical analysis of MWHA has been conducted using four distinct microwave coaxial antenna (MWCA) designs: a single-tine, a two-tine, a four-tine, and a six-tine configuration. Each design offers adjustable tine length and angle, allowing for precise ablation while minimizing harm to nearby healthy tissue. The MWCA designs are supplied with energy at 2.45 GHz and a power input of 15 W for 10 min. The electromagnetic wave and bioheat transfer physics models have been integrated using COMSOL Multiphysics, with all simulations performed using the Finite Element Method (FEM). The model simulation showed a strong correlation with two ex vivo MWHA studies conducted on pig and cow liver tissues. Single and two-tine designs combine teardrop-shaped and spherical ablation shapes with indiscriminate collateral tissue damage. In contrast, the four and six-tine designs produce a concentrated spherical ablation region with minimum harm to nearby healthy tissues. Moreover, the results show that the tine length can be adjusted to control the extent of tissue ablation, and increased power input results in consistent expansion of the ablation zone. However, high microwave power levels, exceeding 30 W, damage healthy tissues surrounding the targeted treatment area. In addition, the results provide intriguing insights into the thermal dynamics of ablation procedures, specifically illustrating that temperature levels rise with increased power input and closeness to the MWCA. These findings guide clinicians in achieving successful outcomes while minimizing the risk of thermal damage during MWHA procedures.