PURPOSE: Computational models of microwave tissue ablation are widely used to guide the development of ablation devices, and are increasingly being used for the development of treatment planning and monitoring platforms. Knowledge of temperature-dependent dielectric properties of lung tissue is essential for accurate modeling of microwave ablation (MWA) of the lung. METHODS: We employed the open-ended coaxial probe method, coupled with a custom tissue heating apparatus, to measure dielectric properties of ex vivo porcine and bovine lung tissue at temperatures ranging between 31 and 150 ∘ C, over the frequency range 500 MHz to 6 GHz. Furthermore, we employed numerical optimization techniques to provide parametric models for characterizing the broadband temperature-dependent dielectric properties of tissue, and their variability across tissue samples, suitable for use in computational models of microwave tissue ablation. RESULTS: Rapid decreases in both relative permittivity and effective conductivity were observed in the temperature range from 94 to 108 ∘ C. Over the measured frequency range, both relative permittivity and effective conductivity were suitably modeled by piecewise linear functions [root mean square error (RMSE) = 1.0952 for permittivity and 0.0650 S/m for conductivity]. Detailed characterization of the variability in lung tissue properties was provided to enable uncertainty quantification of models of MWA. CONCLUSIONS: The reported dielectric properties of lung tissue, and parametric models which also capture their distribution, will aid the development of computational models of microwave lung ablation.

Department of Circuit Theory Czech Technical University Technicka 2 160 00 Praha 6 Czech Republic

Department of Electrical and Computer Engineering Kansas State University 1701D Platt st Manhattan KS 66506 USA

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Ryan TP and Brace CL, Interstitial microwave treatment for cancer: historical basis and current techniques in antenna design and performance, International Journal of Hyperthermia 33, 3–14 (2017). PubMed

Sawicki JF, Luyen H, Mohtashami Y, Shea JD, Behdad N, and Hagness SC, The Performance of Higher-Frequency Microwave Ablation in the Presence of Perfusion, IEEE Transactions on Biomedical Engineering (2018). PubMed

Jones RP, Kitteringham NR, Terlizzo M, Hancock C, Dunne D, Fenwick SW, Poston GJ, Ghaneh P, and Malik HZ, Microwave ablation of ex vivo human liver and colorectal liver metastases with a novel 14.5?GHz generator, International Journal of Hyperthermia 28, 43–54 (2012). PubMed

Chiang J, Wang P, and Brace CL, Computational modelling of microwave tumour ablations, International Journal of Hyperthermia 29, 308–317 (2013). PubMed PMC

Deshazer G, Hagmann M, Merck D, Sebek J, Moore KB, and Prakash P, Computational modeling of 915 MHz microwave ablation: Comparative assessment of temperature-dependent tissue dielectric models, Medical Physics 44, 4859–4868 (2017). PubMed

Sebek J, Curto S, Bortel R, and Prakash P, Analysis of minimally invasive directional antennas for microwave tissue ablation, International Journal of Hyperthermia 33, 51–60 (2017). PubMed

Prakash P, Deng G, Converse MC, Webster JG, Mahvi DM, and Ferris MC, Design optimization of a robust sleeve antenna for hepatic microwave ablation, Physics in Medicine & Biology 53, 1057 (2008). PubMed

Brace CL, Dual-slot antennas for microwave tissue heating: Parametric design analysis and experimental validation, Medical physics 38, 4232–4240 (2011). PubMed PMC

Sebek J, Albin N, Bortel R, Natarajan B, and Prakash P, Sensitivity of microwave ablation models to tissue biophysical properties: A first step toward probabilistic modeling and treatment planning, Medical physics 43, 2649–2661 (2016). PubMed

Prakash P, Theoretical modeling for hepatic microwave ablation, The open biomedical engineering journal 4, 27 (2010). PubMed PMC

Trujillo M and Berjano E, Review of the mathematical functions used to model the temperature dependence of electrical and thermal conductivities of biological tissue in radiofrequency ablation, International Journal of Hyperthermia 29, 590–597 (2013). PubMed

Rossmann C and Haemmerich D, Review of temperature dependence of thermal properties, dielectric properties, and perfusion of biological tissues at hyperthermic and ablation temperatures, Critical Reviews in Biomedical Engineering 42 (2014). PubMed PMC

Cavagnaro M, Pinto R, and Lopresto V, Numerical models to evaluate the temperature increase induced by ex vivo microwave thermal ablation, Physics in Medicine & Biology 60, 3287 (2015). PubMed

Chiang J, Birla S, Bedoya M, Jones D, Subbiah J, and Brace CL, Modeling and validation of microwave ablations with internal vaporization, IEEE Transactions on Biomedical Engineering 62, 657–663 (2015). PubMed PMC

Yang D, Converse MC, Mahvi DM, and Webster JG, Measurement and Analysis of Tissue Temperature During Microwave Liver Ablation, IEEE Transactions on Biomedical Engineering 54, 150–155 (2007). PubMed

Liu D and Brace CL, Numerical simulation of microwave ablation incorporating tissue contraction based on thermal dose, Physics in Medicine & Biology 62, 2070 (2017). PubMed PMC

Ji Z and Brace CL, Expanded modeling of temperature-dependent dielectric properties for microwave thermal ablation, Physics in Medicine & Biology 56, 5249 (2011). PubMed PMC

Lopresto V, Pinto R, Lovisolo GA, and Cavagnaro M, Changes in the dielectric properties of ex vivo bovine liver during microwave thermal ablation at 2.45 GHz, Physics in Medicine & Biology 57, 2309 (2012). PubMed

Lazebnik M, Converse MC, Booske JH, and Hagness SC, Ultrawideband temperature-dependent dielectric properties of animal liver tissue in the microwave frequency range, Physics in Medicine & Biology 51, 1941 (2006). PubMed

Stauffer PR, Rossetto F, Prakash M, Neuman DG, and Lee T, Phantom and animal tissues for modelling the electrical properties of human liver, International Journal of Hyperthermia 19, 89–101 (2003). PubMed

Pfannenstiel A, Keast T, Kramer S, Wibowo H, and Prakash P, Flexible microwave ablation applicator for the treatment of pulmonary malignancies, in Energy-based Treatment of Tissue and Assessment IX, volume 10066, page 100660M, International Society for Optics and Photonics, 2017.

Bonello J, Elahi MA, Porter E, O’Halloran M, Farrugia L, and Sammut CV, An investigation of the variation of dielectric properties of ovine lung tissue with temperature., Biomedical Physics & Engineering Express (2018).

Joines WT, Zhang Y, Li C, and Jirtle RL, The measured electrical properties of normal and malignant human tissues from 50 to 900 MHz, Medical Physics 21, 547–550 (1994). PubMed

Andreano A, Huang Y, Meloni MF, Lee FT, and Brace C, Microwaves create larger ablations than radiofrequency when controlled for power in ex vivo tissue, Medical physics 37, 2967–2973 (2010). PubMed PMC

Brace CL, Diaz TA, Hinshaw JL, and Lee FT Jr, Tissue contraction caused by radiofrequency and microwave ablation: a laboratory study in liver and lung, Journal of Vascular and Interventional Radiology 21, 1280–1286 (2010). PubMed PMC

Fallahi H and Prakash P, Measurement of Broadband Temperature-Dependent Dielectric Properties of Liver Tissue, in 2018 IEEE International Microwave Biomedical Conference (IMBioC), pages 91–93, IEEE, 2018.

Neira LM, Sawicki J, Van Veen BD, and Hagness SC, Characterization and Analysis of Wideband Temperature-Dependent Dielectric Properties of Liver Tissue for Next-Generation Minimally Invasive Microwave Tumor Ablation Technology, in 2018 IEEE/MTT-S International Microwave Symposium-IMS, pages 911–914, IEEE, 2018.

La Gioia A, Porter E, Merunka I, Shahzad A, Salahuddin S, Jones M, and OHallo-ran M, Open-ended coaxial probe technique for dielectric measurement of biological tissues: Challenges and common practices, Diagnostics 8, 40 (2018). PubMed PMC

Meaney PM, Gregory AP, Epstein NR, and Paulsen KD, Microwave open-ended coaxial dielectric probe: Interpretation of the sensing volume re-visited, BMC medical physics 14, 3 (2014). PubMed PMC

Meaney PM, Gregory AP, Seppälä J, and Lahtinen T, Open-ended coaxial dielectric probe effective penetration depth determination, IEEE transactions on microwave theory and techniques 64, 915–923 (2016). PubMed PMC

Porter E and OHalloran M, Investigation of histology region in dielectric measurements of heterogeneous tissues, IEEE Transactions on Antennas and Propagation 65, 5541–5552 (2017). PubMed PMC

Porter E, La Gioia A, Santorelli A, and O’Halloran M, Modeling of the dielectric properties of biological tissues within the histology region, IEEE Transactions on Dielectrics and Electrical Insulation 24, 3290–3301 (2017).

Sawicki JF, Shea JD, Behdad N, and Hagness SC, The impact of frequency on the performance of microwave ablation, International Journal of Hyperthermia 33, 61–68 (2017). PubMed

Fallahi H and Prakash P, Antenna designs for microwave tissue ablation, Critical reviews in biomedical engineering 46, 495 (2018). PubMed PMC

Chen S, Wright N, and Humphrey J, Heat-induced changes in the mechanics of a collagenous tissue: isothermal, isotonic shrinkage, Journal of biomechanical engineering 120, 382–388 (1998). PubMed

Pearce JA, Models for thermal damage in tissues: processes and applications, Critical Reviews in Biomedical Engineering 38 (2010). PubMed

Rao CR, Rao CR, Statistiker M, Rao CR, and Rao CR, Linear statistical inference and its applications, volume 2, Wiley; New York, 1973.

Dewey W, Arrhenius relationships from the molecule and cell to the clinic, International journal of hyperthermia 10, 457–483 (1994). PubMed

Hall SK, Ooi EH, and Payne SJ, Cell death, perfusion and electrical parameters are critical in models of hepatic radiofrequency ablation, International Journal of Hyperthermia 31, 538–550 (2015). PubMed PMC

Lopresto V, Pinto R, Farina L, and Cavagnaro M, Microwave thermal ablation: effects of tissue properties variations on predictive models for treatment planning, Medical engineering & physics 46, 63–70 (2017). PubMed

Orourke AP, Lazebnik M, Bertram JM, Converse MC, Hagness SC, Webster JG, and Mahvi DM, Dielectric properties of human normal, malignant and cirrhotic liver tissue: in vivo and ex vivo measurements from 0.5 to 20 GHz using a precision open-ended coaxial probe, Physics in Medicine & Biology 52, 4707 (2007). PubMed

Porter E, La Gioia A, Salahuddin S, Decker S, Shahzad A, Elahi MA, O’Halloran M, and Beyan O, Minimum information for dielectric measurements of biological tissues (MINDER): A framework for repeatable and reusable data, International Journal of RF and Microwave Computer-Aided Engineering 28, e21201 (2018).

Microwave ablation of lung tumors: A probabilistic approach for simulation-based treatment planning