International Journal of Bioelectronics

Designing Microwave Ablation Applicators for Breast Cancer: Difficulties Associated with Heterogeneous Tissue

Abstract

Microwave ablation has been designed as a minimally invasive thermal therapy for treatment of breast-localized tumor. From a systems point of view the overall performance is not to be determined solely by one given parameter but rather the combination and synergistic effects of applicator design, EM coupling, thermal transport processes as well the inhomogeneity of breast tissue. Herein we review MWA systems for the treatment of breast cancer, with a specific focus on applicator design geometry, electromagnetic–thermal modeling techniques and experimental validation procedures and investigate how tissue heterogeneity affects power deposition and temperature profile. The energy delivery, temperature control and treatment prediction limitations associated with the shift from idealized numerical models to realistic ex vivo and in-vivo studies are addressed. Finally, several open engineering questions and future directions are considered in the context of design optimization and treatment planning under variability in tissue.

Keywords: Microwave ablation, breast cancer, heterogeneous tissue.

Introduction

The incentive of breast cancer to create new therapeutic methods with the reducing invasiveness while maintaining precision has not yet abandoned [1]. The heating method in thermal-based modalities Microwave ablation, among various heat-based modalities, has recently received interest in being able to provide a rapid volumetric heating using applicators which are small-sized and flexible in nature [2]. At the system layer, treatments performed by microwave ablation systems cannot be considered energy-dumping instruments [3]. Their entire behavior is due to the interplay between several parameters, such as applicator geometry, electromagnetic coupling, tissue dielectric properties, and thermal diffusion mechanisms [4]. In practice, relatively small fluctuations of any one of these factors can lead to the large changes in the size, configuration and isotropy of the ablated zone which tend to compromise treatment repeatability [5].

Conclusion

This analysis provided an overview "on technologies" of microwave ablation for breast cancer based on a system approach and bioelectronic point of view, focusing specifically in the applicator design, electromagnetic–thermal modeling and tissue heterogeneity. Instead of presenting microwave ablation as a mature technique, the we have demonstrated some outstanding limitations with impact on its dependability and predictivity.

References

[1] C. L. Brace, “Microwave tissue ablation: biophysics, technology, and applications,” Crit. Rev. Biomed. Eng., vol. 38, no. 1, pp. 65–78, 2010.

[2] J. M. Bertram, D. Yang, M. C. Converse, J. G. Webster, and D. M. Mahvi, “A review of coaxial-based microwave ablation antennas,” IEEE Trans. Biomed. Eng., vol. 53, no. 9, pp. 1937–1949, 2006.

 [3] H. H. Pennes, “Analysis of tissue and arterial blood temperatures in the resting human forearm,” J. Appl. Physiol., vol. 1, no. 2, pp. 93–122, 1948.

[4] I. A. Chang, “Considerations for thermal injury analysis for RF ablation devices,” Open Biomed. Eng. J., vol. 4, pp. 3–12, 2010, doi: 10.2174/1874120701004020003.

[5] D. Yang, M. C. Converse, D. M. Mahvi, and J. G. Webster, “Measurement and analysis of tissue temperature during microwave ablation,” IEEE Trans. Biomed. Eng., vol. 54, no. 8, pp. 150–155, 2007.

[6] S. Gabriel, R. W. Lau, and C. Gabriel, “The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues,” Phys. Med. Biol., vol. 41, no. 11, pp. 2271–2293, 1996.

[7] M. Lazebnik, L. McCartney, D. Popovic, et al., “A large-scale study of the ultrawideband microwave dielectric properties of normal breast tissue obtained from reduction surgeries,” Phys. Med. Biol., vol. 52, no. 10, pp. 2637–2656, 2007.

[8] M. Lazebnik, E. L. Madsen, G. R. Frank, and S. C. Hagness, “Tissue-mimicking phantom materials for microwave imaging,” IEEE Trans. Biomed. Eng., vol. 52, no. 11, pp. 1892–1903, 2005.

[9] S. N. Goldberg, G. S. Gazelle, and P. R. Mueller, “Thermal ablation therapy for focal malignancy: a unified approach to underlying principles, techniques, and diagnostic imaging guidance,” AJR Am. J. Roentgenol., vol. 174, no. 2, pp. 323–331, 2000.

[10] P. Saccomandi, E. Schena, and S. Silvestri, “Techniques for temperature monitoring during thermal ablation: an overview,” Int. J. Hyperthermia, vol. 29, no. 7, pp. 609–619, 2013.

[11] K. Segura Félix, G. D. Guerrero López, M. F. J. Cepeda Rubio, et al., “Computational FEM model and phantom validation of microwave ablation for segmental microcalcifications in breasts using a coaxial double-slot antenna,” BioMed Res. Int., vol. 2021, Art. no. 8858822, 2021, doi: 10.1155/2021/8858822.

[12] J. I. Hernández-Jacquez, M. F. J. Cepeda-Rubio, G. D. Guerrero-López, et al., “In-silico study of microwave ablation applicators of different size for breast cancer treatment,” Ing. Investig. Tecnol., vol. 21, no. 3, pp. 1–13, 2020, doi: 10.22201/fi.25940732e.2020.21.3.025.

[13] G. D. Guerrero López, M. F. J. Cepeda Rubio, J. I. Hernández Jacquez, et al., “Computational FEM model, phantom and ex vivo swine breast validation of an optimized double-slot microcoaxial antenna designed for minimally invasive breast tumor ablation,” Comput. Math. Methods Med., vol. 2017, Art. no. 1562869, 2017, doi: 10.1155/2017/1562869.

[14] R. Pinto et al., “Microwave ablation systems for oncological applications: engineering considerations and challenges,” Curr. Cancer Ther. Rev., 2024, doi: 10.2174/0115733947299809240804192844.

[15] J. A. Neri et al., “Feasibility study for the application of microwave ablation technique to ex-vivo tissue in mastectomies,” in Proc. IEEE GMEPE/PAHCE, Mexicali, Mexico, pp. 1–6, 2025, doi: 10.1109/GMEPE/PAHCE65777.2025.11002840.

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