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Iheanacho F, Rex N, Oueidat K, Collins S, Baird GL, Kim D, Dubel GJ, Jay BS, Maxwell AWP. Prospective Margin Estimates Predict Local Tumor Progression Following Microwave Ablation of Small Renal Masses. Cardiovasc Intervent Radiol 2024; 47:200-207. [PMID: 38151603 DOI: 10.1007/s00270-023-03635-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 11/26/2023] [Indexed: 12/29/2023]
Abstract
PURPOSE To evaluate the relationship between prospectively generated ablative margin estimates and local tumor progression (LTP) among patients undergoing microwave ablation (MWA) of small renal masses (SRMs). MATERIALS AND METHODS Between 2017 and 2020, patients who underwent MWA for SRM were retrospectively identified. During each procedure, segmented kidney and tumor shapes were coregistered with intraprocedural helical CT images obtained after microwave antenna placement. Predicted ablation zone shape and size were then overlaid onto the resultant model, and a model-to-model distance algorithm was employed to calculate multiple ablative margin estimates. LTP was modeled as a function of each margin estimate by hazard regression. Models were evaluated using hazard ratios and Akaike information criterion. Receiver operating characteristic curve area under the curve was also estimated using Harrell's and Uno's C indices (HI and UI, respectively). RESULTS One hundred and twenty-eight patients were evaluated (median age 72.1 years). Mean tumor diameter was 2.4 ± 0.9 cm. LTP was observed in nine (7%) patients. Analysis showed that decreased estimated margin size as measured by first quartile (Q1; 25th percentile), maximum, and average ablative margin metrics was significantly associated with risk of LTP. For every one millimeter increase in Q1, maximum, and mean ablative margin, the hazard of LTP increased 67% (HR: 1.67; 95% CI = 1.25-2.20, UI = 0.93, HI = 0.77), 32% (HR: 1.32; 95% CI 1.09-1.60; UI = 0.93; HI = 0.76), and 48% (HR: 1.48; 95% CI 1.18-1.85; UI = 0.83; HI = 0.75), respectively. CONCLUSION Prospectively generated ablative margin estimates can be used to predict the risk of local tumor progression following microwave ablation of small renal masses. LEVEL OF EVIDENCE 3: Retrospective cohort study.
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Affiliation(s)
- Franklin Iheanacho
- Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, 593 Eddy Street, Providence, RI, 02903, USA
| | - Nathaniel Rex
- Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, 593 Eddy Street, Providence, RI, 02903, USA
| | - Karim Oueidat
- Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, 593 Eddy Street, Providence, RI, 02903, USA.
| | - Scott Collins
- Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, 593 Eddy Street, Providence, RI, 02903, USA
| | - Grayson L Baird
- Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, 593 Eddy Street, Providence, RI, 02903, USA
| | - DaeHee Kim
- Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, 593 Eddy Street, Providence, RI, 02903, USA
| | - Gregory J Dubel
- Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, 593 Eddy Street, Providence, RI, 02903, USA
| | - Bryan S Jay
- Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, 593 Eddy Street, Providence, RI, 02903, USA
| | - Aaron W P Maxwell
- Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, 593 Eddy Street, Providence, RI, 02903, USA
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Jin X, Feng Y, Zhu R, Qian L, Yang Y, Yu Q, Zou Z, Li W, Liu Y, Qian Z. Temperature control and intermittent time-set protocol optimization for minimizing tissue carbonization in microwave ablation. Int J Hyperthermia 2022; 39:868-879. [PMID: 35858640 DOI: 10.1080/02656736.2022.2075041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
PURPOSE The charring tissue formation in the ablated lesion during the microwave ablation (MWA) of tumors would induce various unwanted inflammatory responses. This paper aimed to deliver appropriate thermal dose for effective ablations while preventing tissue carbonization by optimizing the treatment protocol during MWA with the set combinations of temperature control and pulsed microwave energy delivery. MATERIAL AND METHODS The thermal phase transition of ex vivo porcine liver tissues were recorded by differential scanning calorimetry (DSC) to determine the temperature threshold during microwave output control. MWA was performed by an in-house built system with the ease of microwave output parameter adjustment and real-time temperature monitoring. The effects of continuous and pulsed microwave deliveries as well as various intermittent time-set of MWA were evaluated by measuring the dimensions of the coagulation zone and the carbonization zone. RESULTS The DSC scans demonstrated that the ex vivo porcine liver tissues have been in a state of endothermic heat during the heating process, where the maximum absorbed heat occurred at the temperature of 105 °C ± 5 °C. The temperature control during MWA resulted in effective coagulative necrosis while preventing tissue carbonization, after setting 100 °C as the upper threshold temperature and 60 °C as the lower threshold. Both the numerical simulation and ex vivo experiments have shown that, upon the optimization of the time-set parameters in the periodic intermittent pulsed microwave output, the tissue carbonization was significantly diminished. CONCLUSION This study developed a straight-forward anti-carbonization strategy in MWA by modulating the pulsing mode and intermittent time. The programmed protocols of intermittent pulsing MWA have demonstrated its potentials toward future expansion of MWA technology in clinical application.
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Affiliation(s)
- Xiaofei Jin
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Yu Feng
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Roujun Zhu
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Lu Qian
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Yamin Yang
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Qindong Yu
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Zhihan Zou
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Weitao Li
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Yangyang Liu
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Zhiyu Qian
- Department of Biomedical Engineering, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
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Bianchi L, Cavarzan F, Ciampitti L, Cremonesi M, Grilli F, Saccomandi P. Thermophysical and mechanical properties of biological tissues as a function of temperature: a systematic literature review. Int J Hyperthermia 2022; 39:297-340. [DOI: 10.1080/02656736.2022.2028908] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Leonardo Bianchi
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
| | - Fabiana Cavarzan
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
| | - Lucia Ciampitti
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
| | - Matteo Cremonesi
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
| | - Francesca Grilli
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
| | - Paola Saccomandi
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
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Wang M, Scapaticci R, Cavagnaro M, Crocco L. Towards a Microwave Imaging System for Continuous Monitoring of Liver Tumor Ablation: Design and In Silico Validation of an Experimental Setup. DIAGNOSTICS (BASEL, SWITZERLAND) 2021; 11:diagnostics11050866. [PMID: 34065015 PMCID: PMC8150540 DOI: 10.3390/diagnostics11050866] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/04/2021] [Accepted: 05/08/2021] [Indexed: 01/08/2023]
Abstract
Liver cancer is one of the most common liver malignancies worldwide. Thermal ablation has been recognized as a promising method for its treatment, with a significant impact on clinical practice. However, the treatment’s effectiveness is heavily dependent on the experience of the clinician and would improve if paired with an image-guidance device for treatment monitoring. Conventional imaging modalities, such as computed tomography, ultrasound, and magnetic resonance imaging, show some disadvantages, motivating interest in alternative technologies. In this framework, microwave imaging was recently proposed as a potential candidate, being capable of implementing real-time monitoring by means of low-cost and portable devices. In this work, the in silico assessment of a microwave imaging device specifically designed for liver ablation monitoring is presented. To this end, an imaging experiment involving eight Vivaldi antennas in an array configuration and a practically realizable liver phantom mimicking the evolving treatment was simulated. In particular, since the actual phantom will be realized by 3D printing technology, the effect of the plastic shells containing tissues mimicking materials was investigated and discussed. The outcomes of this study confirm that the presence of printing materials does not impair the significance of the experiments and that the designed device is capable of providing 3D images of the ablated region conveying information on its extent and evolution. Moreover, the observed results suggest possible improvements to the system, paving the way for the next stage in which the device will be implemented and experimentally assessed in the same conditions as those simulated in this study.
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Affiliation(s)
- Mengchu Wang
- Institute for the Electromagnetic Sensing of the Environment, National Research Council of Italy, 80124 Napoli, Italy; (R.S.); (M.C.); (L.C.)
- Department of Information Engineering, Electronics and Telecommunications, Sapienza University of Rome, 00184 Rome, Italy
- Correspondence: ; Tel.: +39-081-762-0655
| | - Rosa Scapaticci
- Institute for the Electromagnetic Sensing of the Environment, National Research Council of Italy, 80124 Napoli, Italy; (R.S.); (M.C.); (L.C.)
| | - Marta Cavagnaro
- Institute for the Electromagnetic Sensing of the Environment, National Research Council of Italy, 80124 Napoli, Italy; (R.S.); (M.C.); (L.C.)
- Department of Information Engineering, Electronics and Telecommunications, Sapienza University of Rome, 00184 Rome, Italy
| | - Lorenzo Crocco
- Institute for the Electromagnetic Sensing of the Environment, National Research Council of Italy, 80124 Napoli, Italy; (R.S.); (M.C.); (L.C.)
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Tehrani MHH, Soltani M, Kashkooli FM, Raahemifar K. Use of microwave ablation for thermal treatment of solid tumors with different shapes and sizes-A computational approach. PLoS One 2020; 15:e0233219. [PMID: 32542034 PMCID: PMC7295236 DOI: 10.1371/journal.pone.0233219] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 04/30/2020] [Indexed: 12/11/2022] Open
Abstract
Microwave Ablation (MWA) is one of the most recent developments in the field of thermal therapy. This approach is an effective method for thermal tumor ablation by increasing the temperature above the normal physiological threshold to kill cancer cells with minimum side effects to surrounding organs due to rapid heat dispersive tissues. In the present study, the effects of the shape and size of the tumor on MWA are investigated. To obtain the temperature gradient, coupled bio-heat and electromagnetic equations are solved using a three-dimensional finite element method (FEM). To extract cellular response at different temperatures and times, the three-state mathematical model was employed to achieve the ablation zone size. Results show that treatment of larger tumors is more difficult than that of smaller ones. By doubling the diameter of the tumor, the percentage of dead cancer cells is reduced by 20%. For a spherical tumor smaller than 2 cm, applying 50 W input power compared to 25 W has no significant effects on treatment efficiency and only increases the risk of damage to adjacent tissues. However, for tumors larger than 2 cm, it can increase the ablation zone up to 21%. In the spherical and oblate tumors, the mean percentage of dead cells at 6 GHz is nearly 30% higher than that at 2.45GHz, but for prolate tumors, treatment efficacy is reduced by 10% at a higher frequency. Moreover, the distance between two slots in the coaxial double slot antenna is modified based on the best treatment of prolate tumors. The findings of this study can be used to choose the optimum frequency and the best antenna design according to the shape and size of the tumor.
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Affiliation(s)
- Masoud H. H. Tehrani
- Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran
| | - M. Soltani
- Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran
- Advanced Bioengineering Initiative Center, Computational Medicine Center, K. N. Toosi University of Technology, Tehran, Iran
- Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON, Canada
- Centre for Biotechnology and Bioengineering (CBB), University of Waterloo, Waterloo, ON, Canada
- Cancer Biology Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Kaamran Raahemifar
- Electrical and Computer Engineering Department, Sultan Qaboos University, Muscat, Sultanate of Oman
- Chemical Engineering Department, University of Waterloo, Waterloo, ON, Canada
- College of Information Sciences and Technology (IST), Data Science and Artificial Intelligence Program, Penn State University, State College, Pennsylvania, PA, United States of America
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Silva NP, Bottiglieri A, Conceição RC, O’Halloran M, Farina L. Characterisation of Ex Vivo Liver Thermal Properties for Electromagnetic-Based Hyperthermic Therapies. SENSORS (BASEL, SWITZERLAND) 2020; 20:E3004. [PMID: 32466323 PMCID: PMC7285484 DOI: 10.3390/s20103004] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/21/2020] [Accepted: 05/22/2020] [Indexed: 12/18/2022]
Abstract
Electromagnetic-based hyperthermic therapies induce a controlled increase of temperature in a specific tissue target in order to increase the tissue perfusion or metabolism, or even to induce cell necrosis. These therapies require accurate knowledge of dielectric and thermal properties to optimise treatment plans. While dielectric properties have been well investigated, only a few studies have been conducted with the aim of understanding the changes of thermal properties as a function of temperature; i.e., thermal conductivity, volumetric heat capacity and thermal diffusivity. In this study, we experimentally investigate the thermal properties of ex vivo ovine liver in the hyperthermic temperature range, from 25 °C to 97 °C. A significant increase in thermal properties is observed only above 90 °C. An analytical model is developed to model the thermal properties as a function of temperature. Thermal properties are also investigated during the natural cooling of the heated tissue. A reversible phenomenon of the thermal properties is observed; during the cooling, thermal properties followed the same behaviour observed in the heating process. Additionally, tissue density and water content are evaluated at different temperatures. Density does not change with temperature; mass and volume losses change proportionally due to water vaporisation. A 30% water loss was observed above 90 °C.
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Affiliation(s)
- Nuno P. Silva
- Translational Medical Device Lab, National University of Ireland Galway, H91 TK33 Galway, Ireland; (N.P.S.); (A.B.); (M.O.)
- Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisbon, Portugal
| | - Anna Bottiglieri
- Translational Medical Device Lab, National University of Ireland Galway, H91 TK33 Galway, Ireland; (N.P.S.); (A.B.); (M.O.)
| | - Raquel C. Conceição
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências Universidade de Lisboa, 1749-016 Lisbon, Portugal;
| | - Martin O’Halloran
- Translational Medical Device Lab, National University of Ireland Galway, H91 TK33 Galway, Ireland; (N.P.S.); (A.B.); (M.O.)
| | - Laura Farina
- Translational Medical Device Lab, National University of Ireland Galway, H91 TK33 Galway, Ireland; (N.P.S.); (A.B.); (M.O.)
- CÚRAM, SFI Research Centre for Medical Devices, National University of Ireland Galway, H91 W2TY Galway, Ireland
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Singh S, Melnik R. Coupled thermo-electro-mechanical models for thermal ablation of biological tissues and heat relaxation time effects. Phys Med Biol 2019; 64:245008. [PMID: 31600740 DOI: 10.1088/1361-6560/ab4cc5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Thermal ablation is a widely applied electrosurgical process in medical treatment of soft biological tissues. Numerical modeling and simulations play an important role in prediction of temperature distribution and damage volume during the treatment planning stage of associated therapies. In this contribution we report a coupled thermo-electro-mechanical model, accounting for heat relaxation time, for more accurate and precise prediction of the temperature distribution, tissue deformation and damage volume during the thermal ablation of biological tissues. Finite element solutions are obtained for most widely used percutaneous thermal ablative techniques, viz., radiofrequency ablation (RFA) and microwave ablation (MWA). Importantly, both tissue expansion and shrinkage have been considered for modeling the tissue deformation in the coupled model of high temperature thermal ablation. The coupled model takes into account the non-Fourier effects, considering both single-phase-lag (SPL) and dual-phase-lag (DPL) models of bio-heat transfer. The temperature-dependent electrical and thermal parameters, damage-dependent blood perfusion rate and phase change effect accounting for tissue vaporization have been accounted for obtaining more clinically relevant model. The proposed model predictions are found to be in good agreement against the temperature distribution and damage volume reported by previous experimental studies. The numerical simulation results revealed that the non-Fourier effects cause a decrease in the predicted temperature distribution, tissue deformation and damage volume during the high temperature thermal ablative procedures. Furthermore, the effects of different magnitudes of phase lags of the heat flux and temperature gradient on the predicted treatment outcomes of the considered thermal ablative modalities are also quantified and discussed in detail.
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Affiliation(s)
- Sundeep Singh
- MS2Discovery Interdisciplinary Research Institute, Wilfrid Laurier University, 75 University Avenue West, Waterloo, Ontario N2L 3C5, Canada. Author to whom any correspondence should be addressed
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Liu D, Brace CL. Evaluation of tissue deformation during radiofrequency and microwave ablation procedures: Influence of output energy delivery. Med Phys 2019; 46:4127-4134. [PMID: 31260115 DOI: 10.1002/mp.13688] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 06/07/2019] [Accepted: 06/22/2019] [Indexed: 12/12/2022] Open
Abstract
PURPOSE The purpose of this study was to quantitatively analyze tissue deformation during radiofrequency (RF) and microwave ablation for varying output energy levels. METHODS A total of 46 fiducial markers which were classified into outer, middle, and inner lines were positioned into a single plane around an RF or microwave ablation applicator in each ex vivo bovine liver sample (8 cm × 6 cm × 4 cm, n = 18). Radiofrequency (500 kHz; ~35 W average) or microwave (2.4 GHz; 50-100 W output, ~35-70 W delivered) ablation was performed for 10 min (n = 4-6 each setting). CT images were acquired over the entire liver volume every 15 s. Principle strain magnitude and direction were determined from fiducial marker displacement. Normal and shear strain were then calculated such that negative strain denoted contraction and positive strain denoted expansion. Temporal variations, the final magnitudes, and angles of the strain were compared across energy delivery settings, using one-way ANOVA with post hoc Tukey's tests. RESULTS On average, tissue strain rates peak at around 1 min and decayed exponentially over time. No evidence of tissue expansion was observed. The tissue strains from RF and 50 W, 75 W, and 100 W microwave ablation at 10 min were -8.5%, -38.9%, -54.4%, and -65.7%, respectively, from the inner region and -3.6%, -23.7%, -41.8%, and -44.3%, respectively, from the outer region. Negative strain magnitude was positively correlated to energy delivery in the inner region (Spearman's ρ = -0.99). Microwaves at higher powers (75-100 W) induced significantly more strain than at lower power (50 W) or after RF ablation (P < 0.01). Principal strain angles ranged from 0.8° to -8.1°, indicating that tissue deformed more in the direction transverse to the applicator than along the direction of the applicator. CONCLUSIONS The influence of output energy on tissue deformation during RF and microwave ablation was analyzed. Microwave ablation created significantly greater contraction than RF ablation with similar energy delivery. During microwave ablation, more contraction was noted at higher power levels and in proximity to the antenna. Contraction primarily transverse to the antenna produces ablation zones that are more elongated than the original tissue volume.
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Affiliation(s)
- Dong Liu
- Departments of Radiology, Biomedical Engineering, University of Wisconsin, Madison, WI, 53705, USA
| | - Christopher L Brace
- Departments of Radiology, Biomedical Engineering, University of Wisconsin, Madison, WI, 53705, USA
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Strigari L, Minosse S, D'Alessio D, Farina L, Cavagnaro M, Cassano B, Pinto R, Vallati G, Lopresto V. Microwave thermal ablation using CT-scanner for predicting the variation of ablated region over time: advantages and limitations. Phys Med Biol 2019; 64:115021. [PMID: 30995620 DOI: 10.1088/1361-6560/ab1a67] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This study aims at investigating in real-time the structural and dynamical changes occurring in an ex vivo tissue during a microwave thermal ablation (MTA) procedure. The experimental set-up was based on ex vivo liver tissue inserted in a dedicated box, in which 3 fibre-optic (FO) temperature probes were introduced to measure the temperature increase over time. Computed tomography (CT) imaging technique was exploited to experimentally study in real-time the Hounsfield Units (HU) modification occurring during MTA. The collected image data were processed with a dedicated MATLAB tool, developed to analyse the FO positions and HU modifications from the CT images acquired over time before and during the ablation procedures. The radial position of a FO temperature probe (rFO) and the value of HU in the region of interest (ROI) containing the probe (HUo), along with the corresponding value of HU in the contralateral ROI with respect to the MTA antenna applicator (HUc), were determined and registered over time during and after the MTA procedure. Six experiments were conducted to confirm results. The correlation between temperature and the above listed predictors was investigated using univariate and multivariate analysis. At the multivariate analysis, the time, rFO and HUc resulted significant predictive factors of the logarithm of measured temperature. The correlation between predicted and measured temperatures was 0.934 (p < 0.001). The developed tool allows identifying and registering the image-based parameters useful for predicting the temperature variation over time in each investigated voxel by taking into consideration the HU variation.
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Affiliation(s)
- L Strigari
- Laboratory of Medical Physics and Expert Systems, IRCCS Regina Elena National Cancer Institute, IFO, via Elio Chianesi, 53, 00144, Rome, Italy. Current address: Department of Medical Physics, St. Orsola-Malpighi University Hospital, via Massarenti 9 40138 Bologna, Italy
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Lopresto V, Argentieri A, Pinto R, Cavagnaro M. Temperature dependence of thermal properties of ex vivo liver tissue up to ablative temperatures. ACTA ACUST UNITED AC 2019; 64:105016. [DOI: 10.1088/1361-6560/ab1663] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Scapaticci R, Lopresto V, Pinto R, Cavagnaro M, Crocco L. Monitoring Thermal Ablation via Microwave Tomography: An Ex Vivo Experimental Assessment. Diagnostics (Basel) 2018; 8:E81. [PMID: 30563280 PMCID: PMC6316129 DOI: 10.3390/diagnostics8040081] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/27/2018] [Accepted: 12/02/2018] [Indexed: 12/19/2022] Open
Abstract
Thermal ablation treatments are gaining a lot of attention in the clinics thanks to their reduced invasiveness and their capability of treating non-surgical patients. The effectiveness of these treatments and their impact in the hospital's routine would significantly increase if paired with a monitoring technique able to control the evolution of the treated area in real-time. This is particularly relevant in microwave thermal ablation, wherein the capability of treating larger tumors in a shorter time needs proper monitoring. Current diagnostic imaging techniques do not provide effective solutions to this issue for a number of reasons, including economical sustainability and safety. Hence, the development of alternative modalities is of interest. Microwave tomography, which aims at imaging the electromagnetic properties of a target under test, has been recently proposed for this scope, given the significant temperature-dependent changes of the dielectric properties of human tissues induced by thermal ablation. In this paper, the outcomes of the first ex vivo experimental study, performed to assess the expected potentialities of microwave tomography, are presented. The paper describes the validation study dealing with the imaging of the changes occurring in thermal ablation treatments. The experimental test was carried out on two ex vivo bovine liver samples and the reported results show the capability of microwave tomography of imaging the transition between ablated and untreated tissue. Moreover, the discussion section provides some guidelines to follow in order to improve the achievable performances.
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Affiliation(s)
- Rosa Scapaticci
- National Research Council of Italy-Institute for the Electromagnetic Sensing of the Environment, 80124 Napoli, Italy.
| | - Vanni Lopresto
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Division of Health Protection Technologies, Casaccia Research Center, 00123 Rome, Italy.
| | - Rosanna Pinto
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Division of Health Protection Technologies, Casaccia Research Center, 00123 Rome, Italy.
| | - Marta Cavagnaro
- Department of Information Engineering, Electronics and Telecommunications, Sapienza University of Rome, 00184 Rome, Italy.
| | - Lorenzo Crocco
- National Research Council of Italy-Institute for the Electromagnetic Sensing of the Environment, 80124 Napoli, Italy.
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