Ethylcellulose-stabilized fat-tissue phantom for quality assurance in clinical hyperthermia
Journal article, 2023

Background: Phantoms accurately mimicking the electromagnetic and thermal properties of human tissues are essential for the development, characterization, and quality assurance (QA) of clinically used equipment for Hyperthermia Treatment (HT). Currently, a viable recipe for a fat equivalent phantom is not available, mainly due to challenges in the fabrication process and fast deterioration. Materials and methods: We propose to employ a glycerol-in-oil emulsion stabilized with ethylcellulose to develop a fat-mimicking material. The dielectric, rheological, and thermal properties of the phantom have been assessed by state-of-the-art measurement techniques. The full-size phantom was then verified in compliance with QA guidelines for superficial HT, both numerically and experimentally, considering the properties variability. Results: Dielectric and thermal properties were proven equivalent to fat tissue, with an acceptable variability, in the 8 MHz to 1 GHz range. The rheology measurements highlighted enhanced mechanical stability over a large temperature range. Both numerical and experimental evaluations proved the suitability of the phantom for QA procedures. The impact of the dielectric property variations on the temperature distribution has been numerically proven to be limited (around 5%), even if higher for capacitive devices (up to 20%). Conclusions: The proposed fat-mimicking phantom is a good candidate for hyperthermia technology assessment processes, adequately representing both dielectric and thermal properties of the human fat tissue while maintaining structural stability even at elevated temperatures. However, further experimental investigations on capacitive heating devices are necessary to better assess the impact of the low electrical conductivity values on the thermal distribution.

quality assurance

microwaves

Hyperthermia

phantom

ethylcellulose

Author

Mattia de Lazzari

Chalmers, Electrical Engineering, Signal Processing and Biomedical Engineering

Anna Ström

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Laura Farina

National University of Ireland

Nuno P. Silva

National University of Ireland

S. Curto

Erasmus MC Cancer Institute

Hana Dobsicek Trefna

Chalmers, Electrical Engineering, Signal Processing and Biomedical Engineering

International Journal of Hyperthermia

0265-6736 (ISSN) 1464-5157 (eISSN)

Vol. 40 1 2207797

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Subject Categories

Radiology, Nuclear Medicine and Medical Imaging

DOI

10.1080/02656736.2023.2207797

PubMed

37196995

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Latest update

6/2/2023 2