A necessary step when designing electromagnetic-based medical devices is the choice of an optimal matching medium, standing between the patient and the phased array applicator, and the operating frequency. This is crucial to improve the efficiency both from a technical and clinical points of view. In this paper, we propose a new approach, based on the propagation theory, to support the selection of the matching medium properties and the working frequency in a robust way by accounting for patient body shape and properties variability. The case of adjuvant hyperthermia treatment administered to patient with tumors in the pelvic region has been used as a numerical validation in both 2D and 3D patient specific. For this case, the proposed approach suggests an optimal range of working frequencies (130MHz<f<500MHz) and of matching material properties (eb<20), wherein one can select the working conditions depending on the trade-off between penetration and focal spot dimensions as well as other specific requirements. Results have been compared to the working frequencies used by the commercial applicators and using deionized water as matching material. In conclusion, this work proved the validity of the proposed approach in its general-purpose mathematical formulation, thus, paving the way for its wide application.

Biology, Electromagnetic Propagation Theory, Electromagnetics, Employee welfare, Hyperthermia, Matching Material, Media, Medical Device, Medical devices, Microwave Hyperthermia, Optimal matching, Transmission Line Theory
dx.doi.org/10.1109/JERM.2020.3047980, hdl.handle.net/1765/133308
IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology
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Department of Radiation Oncology

Bellizzi, G.G. (Gennaro G.), Sumser, K. (Kemal), & Bevacqua, M.T. (Martina T.). (2020). On The Optimal Matching Medium and The Working Frequency in Deep Pelvic Hyperthermia. IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology. doi:10.1109/JERM.2020.3047980