Breast Cancer Electromagnetic Ablation using a 2.45 GHz Microcoaxial Applicator
DOI: 10.65220/j4x8m9
Authors: Graciela Salinas Lerma*, Mario Candelario Cepeda Medina, José Irving Hernández Jacquez, Francisco Flores García, Mario Francisco Jesús Cepeda Rubio, Abril Cepeda Rubio, Geshel David Guerrero López, Kristian Segura Félix
Affiliations: 1) Tecnológico Nacional de México / Instituto Tecnológico de La Laguna, Torreón, Coahuila, Mexico · 2) Universidad Autónoma de La Laguna, Torreón, Coahuila, Mexico · 3) Universidad Tecnológica de Torreón, Torreón, Coahuila, Mexico
Received: 2 September 2022 · Accepted: 2 October 2022 · Published: 9 October 2022
Open Access: CC BY 4.0 (post–peer review & technical editing).
Peer Review: Double-blind; at least two independent reviewers.
Abstract
In this work, heating effects from the antenna during the thermal ablation process are modeled using the Finite Element Method (FEM) to solve the Bioheat equation. The model assumes a coaxial slot antenna immersed in homogeneous breast tissue with a spherical tumor. Inner and outer conductors are treated as perfect electric conductors with axial symmetry along the z-axis. After solving the electromagnetic model, we analyze ablation temperature distribution and antenna efficiency.
Keywords: Ablation, Breast cancer, Microwave, Modeling.
Introduction
Breast cancer remains the most common cancer among women worldwide. Minimally invasive approaches such as microwave ablation (MWA) leverage localized heating to induce necrosis, with energy deposition largely governed by SAR and by the dielectric/thermal properties of tissue. MWA can preferentially heat high–water-content carcinomas versus adipose and glandular tissues, offering a broader active heating zone than radiofrequency ablation. Computational electromagnetics—particularly FEM—provides fast and accurate solutions for coupled EM–thermal problems in antenna design.
Methodology
We adopt an axisymmetric transverse magnetic formulation for a TEM wave in a coaxial cable at 2.45 GHz. The source is modeled with a low-reflection boundary; the reflection coefficient and SAR are computed, and thermal response is obtained via Pennes’ bioheat equation. Material dimensions and properties (breast tissue, tumor, cable layers) follow literature values. The mesh (≈4,835 triangular elements) is refined near the antenna slot to resolve peak fields and temperatures.
Results
At 10 W, the steady-state 60 °C isotherm demarcates the ablation zone around the applicator. The reflection coefficient at 2.45 GHz was −4.55 dB. The simulated SAR pattern drives selective heating, and the thermal field confirms a focused region consistent with targeted tumor ablation.
Conclusion
The axisymmetric EM–thermal model of a coaxial slot antenna effectively predicts temperature fields and antenna performance for MWA in breast tissue. Results support the feasibility of the microcoaxial applicator for selective tumor ablation and motivate ongoing experimental validation and optimization.
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© 2022 International Journal of Bioelectronics (IJBIOE). Article licensed under CC BY 4.0.
