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Jacobs EJ, Campelo SN, Aycock KN, Yao D, Davalos RV. Spatiotemporal estimations of temperature rise during electroporation treatments using a deep neural network. Comput Biol Med 2023; 161:107019. [PMID: 37220706 DOI: 10.1016/j.compbiomed.2023.107019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 04/14/2023] [Accepted: 05/05/2023] [Indexed: 05/25/2023]
Abstract
The nonthermal mechanism for irreversible electroporation has been paramount for treating tumors and cardiac tissue in anatomically sensitive areas, where there is concern about damage to nearby bowels, ducts, blood vessels, or nerves. However, Joule heating still occurs as a secondary effect of applying current through a resistive tissue and must be minimized to maintain the benefits of electroporation at high voltages. Numerous thermal mitigation protocols have been proposed to minimize temperature rise, but intraoperative temperature monitoring is still needed. We show that an accurate and robust temperature prediction AI model can be developed using estimated tissue properties (bulk and dynamic conductivity), known geometric properties (probe spacing), and easily measurable treatment parameters (applied voltage, current, and pulse number). We develop the 2-layer neural network on realistic 2D finite element model simulations with conditions encompassing most electroporation applications. Calculating feature contributions, we found that temperature prediction is mostly dependent on current and pulse number and show that the model remains accurate when incorrect tissue properties are intentionally used as input parameters. Lastly, we show that the model can predict temperature rise within ex vivo perfused porcine livers, with error <0.5 °C. This model, using easily acquired parameters, is shown to predict temperature rise in over 1000 unique test conditions with <1 °C error and no observable outliers. We believe the use of simple, readily available input parameters would allow this model to be incorporated in many already available electroporation systems for real-time temperature estimations.
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Affiliation(s)
- Edward J Jacobs
- Department of Biomedical Engineering and Mechanics, Virginia Tech-Wake Forest University, Blacksburg, VA, USA.
| | - Sabrina N Campelo
- Department of Biomedical Engineering and Mechanics, Virginia Tech-Wake Forest University, Blacksburg, VA, USA
| | - Kenneth N Aycock
- Department of Biomedical Engineering and Mechanics, Virginia Tech-Wake Forest University, Blacksburg, VA, USA
| | - Danfeng Yao
- Department of Computer Science, Virginia Tech, Blacksburg, VA, USA
| | - Rafael V Davalos
- Department of Biomedical Engineering and Mechanics, Virginia Tech-Wake Forest University, Blacksburg, VA, USA
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2
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Ranjbartehrani P, Etheridge M, Ramadhyani S, Natesan H, Bischof J, Shao Q. Characterization of Miniature Probes for Cryosurgery, Thermal Ablation, and Irreversible Electroporation on Small Animals. ADVANCED THERAPEUTICS 2022. [DOI: 10.1002/adtp.202100212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Pegah Ranjbartehrani
- Department of Mechanical Engineering University of Minnesota Minneapolis MN 55455 USA
| | - Michael Etheridge
- Department of Mechanical Engineering University of Minnesota Minneapolis MN 55455 USA
| | | | | | - John Bischof
- Department of Mechanical Engineering University of Minnesota Minneapolis MN 55455 USA
- Department of Biomedical Engineering University of Minnesota Minneapolis MN 55455 USA
| | - Qi Shao
- Department of Mechanical Engineering University of Minnesota Minneapolis MN 55455 USA
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3
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Comparison of analysis methods for determination of dynamic tissue conductivity during microseconds-long pulsed electric fields. Biomed Signal Process Control 2022. [DOI: 10.1016/j.bspc.2021.103305] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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4
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Guo F, Deng H, Qian K, Li X. Characterization of dispersion and anisotropic-conductivity in tissue model during electroporation pulses. Bioelectrochemistry 2021; 144:108029. [PMID: 34894430 DOI: 10.1016/j.bioelechem.2021.108029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/22/2021] [Accepted: 11/28/2021] [Indexed: 12/15/2022]
Abstract
Electroporation occurs when biological cells are exposed to intensive, short-duration pulses, which can be used to ablate biological tumor tissues. Based on the traditional numerical models, the isotropic conductivity model with the non-dispersion effect (ICND), the anisotropic conductivity model with the dispersion effect (ACD) is developed in this study. The second-order Debye function is introduced to manifest the dielectric relaxation effect, and the two-dimensional Cartesian conductivity matrix is applied to describe the anisotropy of the tissue conductivity during the electroporation process. A monopolar pulse and a monopolar burst are applied to the breast tumor model through the two-needle electrodes configuration. The results show that taking the dispersion into account can increase the total electroporated area more than 2.31%. Considering the conductivity anisotropy, the total electroporated area increases, but the irreversible electroporation (IRE) area decreases by more than 3.99%. The ACD model can achieve a larger electroporated area but a relatively smaller IRE area than those of the ICND model, and comparably minor maximum thermal damage is evaluated in the ACD model. Our model analyzes the effects of the dielectric dispersion and anisotropic conductivity of tissue, which have strong guiding significance for making the treatment planning before clinical practice.
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Affiliation(s)
- Fei Guo
- Institute of Ecological Safety, Chongqing University of Posts and Telecommunications, Chongqing 400065, China.
| | - Hao Deng
- Institute of Ecological Safety, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Kun Qian
- Institute of Ecological Safety, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Xin Li
- Institute of Ecological Safety, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
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5
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Aycock KN, Zhao Y, Lorenzo MF, Davalos RV. A Theoretical Argument for Extended Interpulse Delays in Therapeutic High-Frequency Irreversible Electroporation Treatments. IEEE Trans Biomed Eng 2021; 68:1999-2010. [PMID: 33400646 PMCID: PMC8291206 DOI: 10.1109/tbme.2021.3049221] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
High-frequency irreversible electroporation (H-FIRE) is a tissue ablation modality employing bursts of electrical pulses in a positive phase-interphase delay (d1)-negative phase-interpulse delay (d2) pattern. Despite accumulating evidence suggesting the significance of these delays, their effects on therapeutic outcomes from clinically-relevant H-FIRE waveforms have not been studied extensively. OBJECTIVE We sought to determine whether modifications to the delays within H-FIRE bursts could yield a more desirable clinical outcome in terms of ablation volume versus extent of tissue excitation. METHODS We used a modified spatially extended nonlinear node (SENN) nerve fiber model to evaluate excitation thresholds for H-FIRE bursts with varying delays. We then calculated non-thermal tissue ablation, thermal damage, and excitation in a clinically relevant numerical model. RESULTS Excitation thresholds were maximized by shortening d1, and extension of d2 up to 1,000 μs increased excitation thresholds by at least 60% versus symmetric bursts. In the ablation model, long interpulse delays lowered the effective frequency of burst waveforms, modulating field redistribution and reducing heat production. Finally, we demonstrate mathematically that variable delays allow for increased voltages and larger ablations with similar extents of excitation as symmetric waveforms. CONCLUSION Interphase and interpulse delays play a significant role in outcomes resulting from H-FIRE treatment. SIGNIFICANCE Waveforms with short interphase delays (d1) and extended interpulse delays (d2) may improve therapeutic efficacy of H-FIRE as it emerges as a clinical tissue ablation modality.
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Affiliation(s)
- Kenneth N. Aycock
- Department of Biomedical Engineering and Mechanics, Bioelectromechanical Systems Laboratory at Virginia Tech, Blacksburg, VA 24061 USA
| | - Yajun Zhao
- Department of Biomedical Engineering and Mechanics, Bioelectromechanical Systems Laboratory at Virginia Tech, Blacksburg, VA 24061 USA
| | - Melvin F. Lorenzo
- Department of Biomedical Engineering and Mechanics, Bioelectromechanical Systems Laboratory at Virginia Tech, Blacksburg, VA 24061 USA
| | - Rafael V. Davalos
- Department of Biomedical Engineering and Mechanics, Bioelectromechanical Systems Laboratory at Virginia Tech, Blacksburg, VA 24061 USA
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Lorenzo MF, Bhonsle SP, Arena CB, Davalos RV. Rapid Impedance Spectroscopy for Monitoring Tissue Impedance, Temperature, and Treatment Outcome During Electroporation-Based Therapies. IEEE Trans Biomed Eng 2021; 68:1536-1546. [PMID: 33156779 PMCID: PMC8127872 DOI: 10.1109/tbme.2020.3036535] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Electroporation-based therapies (EBTs) employ high voltage pulsed electric fields (PEFs) to permeabilize tumor tissue; this results in changes in electrical properties detectable using electrical impedance spectroscopy (EIS). Currently, commercial potentiostats for EIS are limited by impedance spectrum acquisition time ( ∼ 10 s); this timeframe is much larger than pulse periods used with EBTs ( ∼ 1 s). In this study, we utilize rapid EIS techniques to develop a methodology for characterizing electroporation (EP) and thermal effects associated with high-frequency irreversible EP (H-FIRE) in real-time by monitoring inter-burst impedance changes. METHODS A charge-balanced, bipolar rectangular chirp signal is proposed for rapid EIS. Validation of rapid EIS measurements against a commercial potentiostat was conducted in potato tissue using flat-plate electrodes and thereafter for the measurement of impedance changes throughout IRE treatment. Flat-plate electrodes were then utilized to uniformly heat potato tissue; throughout high-voltage H-FIRE treatment, low-voltage inter-burst impedance measurements were used to continually monitor impedance change and to identify a frequency at which thermal effects are delineated from EP effects. RESULTS Inter-burst impedance measurements (1.8 kHz - 4.93 MHz) were accomplished at 216 discrete frequencies. Impedance measurements at frequencies above ∼ 1 MHz served to delineate thermal and EP effects in measured impedance. CONCLUSION We demonstrate rapid-capture ( 1 s) EIS which enables monitoring of inter-burst impedance in real-time. For the first time, we show impedance analysis at high frequencies can delineate thermal effects from EP effects in measured impedance. SIGNIFICANCE The proposed waveform demonstrates the potential to perform inter-burst EIS using PEFs compatible with existing pulse generator topologies.
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Establishing an immunocompromised porcine model of human cancer for novel therapy development with pancreatic adenocarcinoma and irreversible electroporation. Sci Rep 2021; 11:7584. [PMID: 33828203 PMCID: PMC8027815 DOI: 10.1038/s41598-021-87228-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 03/25/2021] [Indexed: 02/07/2023] Open
Abstract
New therapies to treat pancreatic cancer are direly needed. However, efficacious interventions lack a strong preclinical model that can recapitulate patients’ anatomy and physiology. Likewise, the availability of human primary malignant tissue for ex vivo studies is limited. These are significant limitations in the biomedical device field. We have developed RAG2/IL2RG deficient pigs using CRISPR/Cas9 as a large animal model with the novel application of cancer xenograft studies of human pancreatic adenocarcinoma. In this proof-of-concept study, these pigs were successfully generated using on-demand genetic modifications in embryos, circumventing the need for breeding and husbandry. Human Panc01 cells injected subcutaneously into the ears of RAG2/IL2RG deficient pigs demonstrated 100% engraftment with growth rates similar to those typically observed in mouse models. Histopathology revealed no immune cell infiltration and tumor morphology was highly consistent with the mouse models. The electrical properties and response to irreversible electroporation of the tumor tissue were found to be similar to excised human pancreatic cancer tumors. The ample tumor tissue produced enabled improved accuracy and modeling of the electrical properties of tumor tissue. Together, this suggests that this model will be useful and capable of bridging the gap of translating therapies from the bench to clinical application.
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Ding L, Moser M, Luo Y, Zhang W, Zhang B. Treatment Planning Optimization in Irreversible Electroporation for Complete Ablation of Variously Sized Cervical Tumors: A Numerical Study. J Biomech Eng 2021; 143:014503. [PMID: 34043747 DOI: 10.1115/1.4047551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Indexed: 01/04/2023]
Abstract
Irreversible electroporation (IRE), a relatively new energy-based tumor ablation technology, has shown itself in the last decade to be able to safely ablate tumors with favorable clinical outcomes, yet little work has been done on optimizing the IRE protocol to variously sized tumors. Incomplete tumor ablation has been shown to be the main reason leading to the local recurrence and thus treatment failure. The goal of this study was to develop a general optimization approach to optimize the IRE protocol for cervical tumors in different sizes, while minimizing the damage to normal tissues. This kind of approach can lay a foundation for future personalized treatment of IRE. First, a statistical IRE cervical tumor death model was built using previous data in our group. Then, a multi-objective optimization problem model was built, in which the decision variables are five IRE-setting parameters, namely, the pulse strength (U), the length of active tip (H), the number of pulses delivered in one round between a pair of electrodes (A), the distance between electrodes (D), and the number of electrodes (N). The domains of the decision variables were determined based on the clinical experience. Finally, the problem model was solved by using nondominated sorting genetic algorithms II (NSGA-II) algorithm to give respective optimal protocol for three sizes of cervical tumors. Every protocol was assessed by the evaluation criterion established in the study to show the efficacy in a more straightforward way. The results of the study demonstrate this approach can theoretically provide the optimal IRE protocol for different sizes of tumors and may be generalizable to other types, sizes, and locations of tumors.
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Affiliation(s)
- Lujia Ding
- School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Michael Moser
- Department of Surgery, University of Saskatchewan, Saskatoon, SK S7N 0W8, Canada
| | - Yigang Luo
- Department of Surgery, University of Saskatchewan, Saskatoon, SK S7N 0W8, Canada
| | - Wenjun Zhang
- School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China
- Division of Biomedical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9, Canada
| | - Bing Zhang
- Energy-Based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200444, China
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Tai H, Khairalseed M, Hoyt K. 3-D H-Scan Ultrasound Imaging and Use of a Convolutional Neural Network for Scatterer Size Estimation. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:2810-2818. [PMID: 32653207 PMCID: PMC7484237 DOI: 10.1016/j.ultrasmedbio.2020.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 05/25/2020] [Accepted: 06/01/2020] [Indexed: 05/29/2023]
Abstract
H-Scan ultrasound (US) is a new imaging technology that estimates the relative size of acoustic scattering objects and structures. The purpose of this study was to introduce a three-dimensional (3-D) H-scan US imaging approach for scatterer size estimation in volume space. Using a programmable research scanner (Vantage 256, Verasonics Inc, Kirkland, WA, USA) equipped with a custom volumetric imaging transducer (4 DL7, Vermon, Tours, France), raw radiofrequency (RF) data was collected for offline processing to generate H-scan US volumes. A deep convolutional neural network (CNN) was modified and used to achieve voxel mapping from the input H-scan US image to underlying scatterer size. Preliminary studies were conducted using homogeneous gelatin-based tissue-mimicking phantom materials embedded with acoustic scatterers of varying size (15 to 250 μm) and concentrations (0.1 to 1%). Two additional phantoms were embedded with 63 or 125 µm-sized microspheres and used to test CNN estimation accuracy. In vitro results indicate that 3-D H-scan US imaging can visualize the spatial distribution of acoustic scatterers of varying size at different concentrations (R2 > 0.85, p < 0.03). The result of scatterer size estimation reveals that a CNN can achieve an average mapping accuracy of 93.3%. Overall, our preliminary in vitro findings reveal that 3-D H-scan US imaging allows the visualization of tissue scatterer patterns and incorporation of a CNN can be used to help estimate size of the acoustic scattering objects.
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Affiliation(s)
- Haowei Tai
- Department of Electrical and Computer Engineering, University of Texas at Dallas, Richardson, TX, USA
| | - Mawia Khairalseed
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
| | - Kenneth Hoyt
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA; Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Electrical and Computer Engineering, University of Texas at Dallas, Richardson, TX, USA.
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10
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Brock RM, Beitel-White N, Davalos RV, Allen IC. Starting a Fire Without Flame: The Induction of Cell Death and Inflammation in Electroporation-Based Tumor Ablation Strategies. Front Oncol 2020; 10:1235. [PMID: 32850371 PMCID: PMC7399335 DOI: 10.3389/fonc.2020.01235] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 06/16/2020] [Indexed: 12/17/2022] Open
Abstract
New therapeutic strategies and paradigms are direly needed for the treatment of cancer. While the surgical removal of tumors is favored in most cancer treatment plans, resection options are often limited based on tumor localization. Over the last two decades, multiple tumor ablation strategies have emerged as promising stand-alone or combination therapeutic options for patients. These strategies are often employed to treat tumors in areas where surgical resection is not possible or where chemotherapeutics have proven ineffective. The type of cell death induced by the ablation modality is a critical aspect of therapeutic success that can impact the efficacy of the treatment and systemic anti-tumor immune system responses. Electroporation-based ablation technologies include electrochemotherapy, irreversible electroporation, and other modalities that rely on pulsed electric fields to create pores in cell membranes. These pores can either be reversible or irreversible depending on the electric field parameters and can induce cell death either alone or in combination with a therapeutic agent. However, there have been many controversial findings among these technologies as to the cell death type initiated, from apoptosis to pyroptosis. As cell death mechanisms can impact treatment side effects and efficacy, we review the main types of cell death induced by electroporation-based treatments and summarize the impact of these mechanisms on treatment response. We also discuss potential reasons behind the variability of findings such as the similarities between cell death pathways, differences between cell-types, and the variation in electric field strength across the treatment area.
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Affiliation(s)
- Rebecca M. Brock
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Polytechnic Institute and State University, Roanoke, VA, United States
| | - Natalie Beitel-White
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
- Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Rafael V. Davalos
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Irving C. Allen
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Polytechnic Institute and State University, Roanoke, VA, United States
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Science, Blacksburg, VA, United States
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López-Alonso B, Sarnago H, Lucía Ó, Briz P, Burdío JM. Real-Time Impedance Monitoring During Electroporation Processes in Vegetal Tissue Using a High-Performance Generator. SENSORS 2020; 20:s20113158. [PMID: 32498417 PMCID: PMC7309040 DOI: 10.3390/s20113158] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/26/2020] [Accepted: 06/01/2020] [Indexed: 12/13/2022]
Abstract
Classical application of electroporation is carried out by using fixed protocols that do not clearly assure the complete ablation of the desired tissue. Nowadays, new methods that pursue the control of the treatment by studying the change in impedance during the applied pulses as a function of the electric field are being developed. These types of control seek to carry out the treatment in the fastest way, decreasing undesired effects and treatment time while ensuring the proper tumour ablation. The objective of this research is to determine the state of the treatment by continuously monitoring the impedance by using a novel versatile high-voltage generator and sensor system. To study the impedance dynamics in real time, the use of pulses of reduced voltage, below the threshold of reversible electroporation, is tested to characterise the state-of-the-treatment without interfering with it. With this purpose, a generator that provides both low voltage for sense tissue changes and high voltage for irreversible electroporation (IRE) was developed. In conclusion, the characterisation of the effects of electroporation in vegetal tissue, combined with the real-time monitoring of the state-of-the-treatment, will enable the provision of safer and more effective treatments.
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12
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O'Brien TJ, Passeri M, Lorenzo MF, Sulzer JK, Lyman WB, Swet JH, Vrochides D, Baker EH, Iannitti DA, Davalos RV, McKillop IH. Experimental High-Frequency Irreversible Electroporation Using a Single-Needle Delivery Approach for Nonthermal Pancreatic Ablation In Vivo. J Vasc Interv Radiol 2020; 30:854-862.e7. [PMID: 31126597 DOI: 10.1016/j.jvir.2019.01.032] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 01/23/2019] [Accepted: 01/30/2019] [Indexed: 02/07/2023] Open
Abstract
PURPOSE To investigate the feasibility of single-needle high-frequency irreversible electroporation (SN-HFIRE) to create reproducible tissue ablations in an in vivo pancreatic swine model. MATERIALS AND METHODS SN-HFIRE was performed in swine pancreas in vivo in the absence of intraoperative paralytics or cardiac synchronization using 3 different voltage waveforms (1-5-1, 2-5-2, and 5-5-5 [on-off-on times (μs)], n = 6/setting) with a total energized time of 100 μs per burst. At necropsy, ablation size/shape was determined. Immunohistochemistry was performed to quantify apoptosis using an anticleaved caspase-3 antibody. A numerical model was developed to determine lethal thresholds for each waveform in pancreas. RESULTS Mean tissue ablation time was 5.0 ± 0.2 minutes, and no cardiac abnormalities or muscle twitch was detected. Mean ablation area significantly increased with increasing pulse width (41.0 ± 5.1 mm2 [range 32-66 mm2] vs 44 ± 2.1 mm2 [range 38-56 mm2] vs 85.0 ± 7.0 mm2 [range 63-155 mm2]; 1-5-1, 2-5-2, 5-5-5, respectively; p < 0.0002 5-5-5 vs 1-5-1 and 2-5-2). The majority of the ablation zone did not stain positive for cleaved caspase-3 (6.1 ± 2.8% [range 1.8-9.1%], 8.8 ± 1.3% [range 5.5-14.0%], and 11.0 ± 1.4% [range 7.1-14.2%] cleaved caspase-3 positive 1-5-1, 2-5-2, 5-5-5, respectively), with significantly more positive staining at the 5-5-5 pulse setting compared with 1-5-1 (p < 0.03). Numerical modeling determined a lethal threshold of 1114 ± 123 V/cm (1-5-1 waveform), 1039 ± 103 V/cm (2-5-2 waveform), and 693 ± 81 V/cm (5-5-5 waveform). CONCLUSIONS SN-HFIRE induces rapid, predictable ablations in pancreatic tissue in vivo without the need for intraoperative paralytics or cardiac synchronization.
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Affiliation(s)
- Timothy J O'Brien
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, Virginia; Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences, Blacksburg, Virginia
| | - Michael Passeri
- Department of Surgery, Division of HPB Surgery, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203
| | - Melvin F Lorenzo
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, Virginia; Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences, Blacksburg, Virginia
| | - Jesse K Sulzer
- Department of Surgery, Division of HPB Surgery, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203
| | - William B Lyman
- Department of Surgery, Division of HPB Surgery, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203
| | - Jacob H Swet
- Department of Surgery, Division of HPB Surgery, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203
| | - Dionisios Vrochides
- Department of Surgery, Division of HPB Surgery, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203
| | - Erin H Baker
- Department of Surgery, Division of HPB Surgery, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203
| | - David A Iannitti
- Department of Surgery, Division of HPB Surgery, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203
| | - Rafael V Davalos
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, Virginia; Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences, Blacksburg, Virginia
| | - Iain H McKillop
- Department of Surgery, Division of HPB Surgery, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, NC 28203.
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Abstract
Electrochemotherapy is gaining recognition as an effective local therapy that uses systemically or intratumorally injected bleomycin or cisplatin with electroporation as a delivery system that brings drugs into the cells to exert their cytotoxic effects. Preclinical work is still ongoing, testing new drugs, seeking the best treatment combination with other treatment modalities, and exploring new sets of pulses for effective tissue electroporation. The applications of electrochemotherapy are being fully exploited in veterinary oncology, where electrochemotherapy, because of its simple execution, has a relatively good cost-benefit ratio and is used in the treatment of cutaneous tumors. In human oncology, electrochemotherapy is fully recognized as a local therapy for cutaneous tumors and metastases. Its effectiveness is being explored in combination with immunomodulatory drugs. However, the development of electrochemotherapy is directed into the treatment of deep-seated tumors with a percutaneous approach. Because of the vast number of reports, this review discusses the articles published in the past 5 years.
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Affiliation(s)
- Maja Cemazar
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Gregor Sersa
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
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14
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Lorenzo MF, Thomas SC, Kani Y, Hinckley J, Lee M, Adler J, Verbridge SS, Hsu FC, Robertson JL, Davalos RV, Rossmeisl JH. Temporal Characterization of Blood-Brain Barrier Disruption with High-Frequency Electroporation. Cancers (Basel) 2019; 11:cancers11121850. [PMID: 31771214 PMCID: PMC6966593 DOI: 10.3390/cancers11121850] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 11/21/2019] [Accepted: 11/22/2019] [Indexed: 12/18/2022] Open
Abstract
Treatment of intracranial disorders suffers from the inability to accumulate therapeutic drug concentrations due to protection from the blood–brain barrier (BBB). Electroporation-based therapies have demonstrated the capability of permeating the BBB, but knowledge of the longevity of BBB disruption (BBBD) is limited. In this study, we quantify the temporal, high-frequency electroporation (HFE)-mediated BBBD in an in vivo healthy rat brain model. 40 male Fisher rats underwent HFE treatment; two blunt tipped monopolar electrodes were advanced into the brain and 200 bursts of HFE were delivered at a voltage-to-distance ratio of 600 V/cm. BBBD was verified with contrast enhanced T1W MRI (gadopentetate dimeglumine) and pathologically (Evans blue dye) at time points of 1, 24, 48, 72, and 96 h after HFE. Contrast enhanced T1W scans demonstrated BBBD for 1 to 72 h after HFE but intact BBB at 96 h. Histologically, tissue damage was restricted to electrode insertion tracks. BBBD was induced with minimal muscle contractions and minimal cell death attributed to HFE. Numerical modeling indicated that brief BBBD was induced with low magnitude electric fields, and BBBD duration increased with field strength. These data suggest the spatiotemporal characteristics of HFE-mediated BBBD may be modulated with the locally applied electric field.
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Affiliation(s)
- Melvin F. Lorenzo
- Bioelectromechanical Systems Laboratory, School of Biomedical Engineering and Sciences, Virginia Tech-Wake Forest University, Blacksburg, VA 24061, USA; (M.F.L.); (M.L.); (R.V.D.)
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; (S.C.T.); (S.S.V.); (J.L.R.)
| | - Sean C. Thomas
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; (S.C.T.); (S.S.V.); (J.L.R.)
| | - Yukitaka Kani
- Department of Small Animal Clinical Sciences, Virginia Tech, Blacksburg, VA 24061, USA; (Y.K.); (J.H.); (J.A.)
| | - Jonathan Hinckley
- Department of Small Animal Clinical Sciences, Virginia Tech, Blacksburg, VA 24061, USA; (Y.K.); (J.H.); (J.A.)
| | - Matthew Lee
- Bioelectromechanical Systems Laboratory, School of Biomedical Engineering and Sciences, Virginia Tech-Wake Forest University, Blacksburg, VA 24061, USA; (M.F.L.); (M.L.); (R.V.D.)
| | - Joy Adler
- Department of Small Animal Clinical Sciences, Virginia Tech, Blacksburg, VA 24061, USA; (Y.K.); (J.H.); (J.A.)
| | - Scott S. Verbridge
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; (S.C.T.); (S.S.V.); (J.L.R.)
| | - Fang-Chi Hsu
- Department of Biostatistics and Data Science, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA;
| | - John L. Robertson
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; (S.C.T.); (S.S.V.); (J.L.R.)
- Department of Small Animal Clinical Sciences, Virginia Tech, Blacksburg, VA 24061, USA; (Y.K.); (J.H.); (J.A.)
| | - Rafael V. Davalos
- Bioelectromechanical Systems Laboratory, School of Biomedical Engineering and Sciences, Virginia Tech-Wake Forest University, Blacksburg, VA 24061, USA; (M.F.L.); (M.L.); (R.V.D.)
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA; (S.C.T.); (S.S.V.); (J.L.R.)
| | - John H. Rossmeisl
- Department of Small Animal Clinical Sciences, Virginia Tech, Blacksburg, VA 24061, USA; (Y.K.); (J.H.); (J.A.)
- Correspondence: ; Tel.: +1-540-231-7288
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15
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DeWitt MR, Latouche EL, Kaufman JD, Fesmire CC, Swet JH, Kirks RC, Baker EH, Vrochides D, Iannitti DA, McKillop IH, Davalos RV, Sano MB. Simplified Non-Thermal Tissue Ablation With a Single Insertion Device Enabled by Bipolar High-Frequency Pulses. IEEE Trans Biomed Eng 2019; 67:2043-2051. [PMID: 31751216 DOI: 10.1109/tbme.2019.2954122] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE To demonstrate the feasibility of a single electrode and grounding pad approach for delivering high frequency irreversible electroporation treatments (H-FIRE) in in-vivo hepatic tissue. METHODS Ablations were created in porcine liver under surgical anesthesia by adminstereing high frequency bursts of 0.5-5.0 μs pulses with amplitudes between 1.1-1.7 kV in the absence of cardiac synchronization or intraoperative paralytics. Finite element simulations were used to determine the electric field strength associated with the ablation margins (ELethal) and predict the ablations feasible with next generation electronics. RESULTS All animals survived the procedures for the protocol duration without adverse events. ELethal of 2550, 1650, and 875 V/cm were found for treatments consisting of 100x bursts containing 0.5 μs pulses and 25, 50, and 75 μs of energized-time per burst, respectively. Treatments with 1 μs pulses consisting of 100 bursts with 100 μs energized-time per burst resulted in ELethal of 650 V/cm. CONCLUSION A single electrode and grounding pad approach was successfully used to create ablations in hepatic tissue. This technique has the potential to reduce challenges associated with placing multiple electrodes in anatomically challenging environments. SIGNIFICANCE H-FIRE is an in situ tumor ablation approach in which electrodes are placed within or around a targeted region to deliver high voltage electrical pulses. Electric fields generated around the electrodes induce irrecoverable cell membrane damage leading to predictable cell death in the relative absence of thermal damage. The sparing of architectural integrity means H-FIRE offers potential advantages compared to thermal ablation modalities for ablating tumors near critical structures.
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16
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Kaufman JD, Fesmire CC, Petrella RA, Fogle CA, Xing L, Gerber D, Sano MB. High-Frequency Irreversible Electroporation Using 5,000-V Waveforms to Create Reproducible 2- and 4-cm Ablation Zones-A Laboratory Investigation Using Mechanically Perfused Liver. J Vasc Interv Radiol 2019; 31:162-168.e7. [PMID: 31530492 DOI: 10.1016/j.jvir.2019.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 05/02/2019] [Accepted: 05/09/2019] [Indexed: 02/07/2023] Open
Abstract
PURPOSE To investigate if high-frequency irreversible electroporation (H-FIRE) treatments can be delivered at higher voltages and with greater energy delivery rates than currently implemented in clinical irreversible electroporation protocols. MATERIALS AND METHODS Treatments using 3,000 V and 5,000 V were administered to mechanically perfused ex vivo porcine liver via a single applicator and grounding pad (A+GP) as well as a 4-applicator array (4AA). Integrated energized times (IET) 0.01-0.08 seconds and energy delivery rates 25-300 μs/s were investigated. Organs were preserved at 4°C for 10-15 hours before sectioning and gross analysis using a metabolic stain to identify the size and shape of ablation zones. RESULTS A+GP ablations measured between 1.6 cm and 2.2 cm, which did not increase when IET was increased from 0.02 seconds to 0.08 seconds (P > .055; range, 1.9-2.1 cm). Changes in tissue color and texture consistent with thermal damage were observed for treatments with energy delivery rates 50-300 μs/s, but not for treatments delivered at 25 μs/s. Use of the 4AA with a 3-cm applicator spacing resulted in ablations measuring 4.4-4.9 cm with energy delivery times of 7-80 minutes. CONCLUSIONS H-FIRE treatments can rapidly and reproducibly create 2-cm ablations using an A+GP configuration. Treatments without thermal injury were produced at the expense of extended treatment times. More rapid treatments resulted in ablations with varying degrees of thermal injury within the H-FIRE ablation zone. Production of 4-cm ablations is possible using a 4AA.
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Affiliation(s)
- Jacob D Kaufman
- UNC/NCSU Joint Department of Biomedical Engineering, Chapel Hill, North Carolina
| | | | - Ross A Petrella
- UNC/NCSU Joint Department of Biomedical Engineering, Chapel Hill, North Carolina
| | - Callie A Fogle
- Departments of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina; Population Health and Pathobiology, North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina
| | - Lei Xing
- Division of Radiation Physics, Department of Radiation Oncology, Stanford University Medical Center, Stanford, California
| | - David Gerber
- Division of Abdominal Transplantation, Department of Surgery, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Michael B Sano
- UNC/NCSU Joint Department of Biomedical Engineering, Chapel Hill, North Carolina.
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17
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Garcia-Sanchez T, Mercadal B, Polrot M, Muscat A, Sarnago H, Lucia O, Mir LM. Successful Tumor Electrochemotherapy Using Sine Waves. IEEE Trans Biomed Eng 2019; 67:1040-1049. [PMID: 31329545 DOI: 10.1109/tbme.2019.2928645] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The purpose of this work is to assess the ability of sine waves to perform electrochemotherapy (ECT) and to study the dependence of the frequency of the applied sine wave on the treatment efficacy. METHODS A subcutaneous tumor model in mice was used, and the electric field was delivered in combination with bleomycin. Sinusoidal electric fields of different frequencies, amplitudes, and durations were compared to square waves. Computer simulations were additionally performed. RESULTS The results confirmed the ability of a sinusoidal electric field to obtain successful ECT responses. A strong dependence on frequency was obtained. The efficacy of the treatment decreased when the frequency of the sine waves was increased. At low sinusoidal frequency, the efficacy of the treatment is very similar to that obtained with a square wave. The collateral effects such as skin burns and muscle contractions decreased for the highest frequency assayed. CONCLUSION The use of sine wave burst represents a feasible option for the treatment of cancer by ECT. SIGNIFICANCE These results could have important implications for the treatment of cancer in the clinical world where ECT is performed with dc square pulses.
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López-Alonso B, Hernáez A, Sarnago H, Naval A, Güemes A, Junquera C, Burdío JM, Castiella T, Monleón E, Gracia-Llanes J, Burdio F, Mejía E, Lucía O. Histopathological and Ultrastructural Changes after Electroporation in Pig Liver Using Parallel-Plate Electrodes and High-Performance Generator. Sci Rep 2019; 9:2647. [PMID: 30804395 PMCID: PMC6389957 DOI: 10.1038/s41598-019-39433-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 01/25/2019] [Indexed: 12/18/2022] Open
Abstract
Irreversible electroporation (IRE) has gained attention as a new non-thermal therapy for ablation with important benefits in terms of homogeneous treatment and fast recovery. In this study, a new concept of high voltage generator is used, enabling irreversible electroporation treatment in large tissue volume using parallel plates. Unlike currently available generators, the proposed versatile structure enables delivering high-voltage high-current pulses. To obtain homogeneous results, 3-cm parallel-plates electrodes have also been designed and implemented. IRE ablation was performed on six female pigs at 2000 V/cm electric field, and the results were analysed after sacrifice three hours, three days and seven days after ablation. Histopathological and ultrastructural studies, including transmission and scanning electron microscopy, were carried out. The developed high-voltage generator has proved to be effective for homogeneous IRE treatment using parallel plates. The destruction of the membrane of the hepatocytes and the alterations of the membranes of the cellular organelles seem incompatible with cell death by apoptosis. Although endothelial cells also die with electroporation, the maintenance of vascular scaffold allows repairing processes to begin from the third day after IRE as long as the blood flow has not been interrupted. This study has opened new direction for IRE using high performance generators and highlighted the importance of taking into account ultrastructural changes after IRE by using electron microscopy analysis.
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Affiliation(s)
- B López-Alonso
- Department of Electronic Engineering and Communications, University of Zaragoza, 50018, Zaragoza, Spain
| | - A Hernáez
- Hospital Clínico Universitario, 50009, Zaragoza, Spain
| | - H Sarnago
- Department of Electronic Engineering and Communications, University of Zaragoza, 50018, Zaragoza, Spain
| | - A Naval
- Department of Electronic Engineering and Communications, University of Zaragoza, 50018, Zaragoza, Spain
| | - A Güemes
- Hospital Clínico Universitario, 50009, Zaragoza, Spain
| | - C Junquera
- Faculty of Medicine, Institute for Health Research Aragón, Zaragoza, Spain
| | - J M Burdío
- Department of Electronic Engineering and Communications, University of Zaragoza, 50018, Zaragoza, Spain
| | - T Castiella
- Faculty of Medicine, Institute for Health Research Aragón, Zaragoza, Spain
| | - E Monleón
- Faculty of Medicine, Institute for Health Research Aragón, Zaragoza, Spain
| | - J Gracia-Llanes
- Faculty of Medicine, Institute for Health Research Aragón, Zaragoza, Spain
| | - F Burdio
- Hospital del Mar, 08018, Barcelona, Spain
| | - E Mejía
- Faculty of Medicine, Institute for Health Research Aragón, Zaragoza, Spain
| | - O Lucía
- Department of Electronic Engineering and Communications, University of Zaragoza, 50018, Zaragoza, Spain.
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19
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Zhang B, Yang Y, Ding L, Moser MAJ, Zhang EM, Zhang W. Tumor Ablation Enhancement by Combining Radiofrequency Ablation and Irreversible Electroporation: An In Vitro 3D Tumor Study. Ann Biomed Eng 2018; 47:694-705. [PMID: 30565007 DOI: 10.1007/s10439-018-02185-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 12/06/2018] [Indexed: 02/08/2023]
Abstract
We hypothesized and demonstrated for the first time that significant tumor ablation enhancement can be achieved by combining radiofrequency ablation (RFA) and irreversible electroporation (IRE) using a 3D cervical cancer cell model. Three RFA (43, 50, and 60 °C for 2 min) and IRE protocols (350, 700, and 1050 V/cm) were used to study the combining effect in the 3D tumor cell model. The in vitro experiment showed that both RFA enhanced IRE and IRE enhanced RFA can lead to a significant increase in the size of the ablation zone compared to IRE and RFA alone. It was also noted that the sequence of applying ablation energy (RFA → RE or IRE → RFA) affected the efficacy of tumor ablation enhancement. The electrical conductivity of 3D tumor was found to be increased after preliminary RFA or IRE treatment. This increase in tumor conductivity may explain the enhancement of tumor ablation. Another explanation might be that there is repeat injury to the transitional zone of the first treatment by the second one. The promising results achieved in the study can provide us useful clues about the treatment of large tumors abutting large vessels or bile ducts.
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Affiliation(s)
- Bing Zhang
- Tumor Ablation Group, Biomedical Science and Technology Research Center, School of Mechatronic Engineering and Automation, Shanghai University, 99 Shangda Road, Baoshan, Shanghai, 200444, China.
| | - Yongji Yang
- School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Lujia Ding
- School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Michael A J Moser
- Department of Surgery, University of Saskatchewan, Saskatoon, SK, S7N 0W8, Canada
| | - Edwin M Zhang
- Division of Vascular & Interventional Radiology, Department of Medical Imaging, University of Toronto, Toronto, ON, M5T 1W7, Canada
| | - Wenjun Zhang
- Tumor Ablation Group, Biomedical Science and Technology Research Center, School of Mechatronic Engineering and Automation, Shanghai University, 99 Shangda Road, Baoshan, Shanghai, 200444, China.,Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, S7N 5A9, Canada
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20
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Poompavai S, Gowri Sree V. Dielectric Property Measurement of Breast—Tumor Phantom Model Under Pulsed Electric Field Treatment. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2018. [DOI: 10.1109/trpms.2018.2868818] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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21
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Zhao Y, Liu H, Bhonsle SP, Wang Y, Davalos RV, Yao C. Ablation outcome of irreversible electroporation on potato monitored by impedance spectrum under multi-electrode system. Biomed Eng Online 2018; 17:126. [PMID: 30236121 PMCID: PMC6148960 DOI: 10.1186/s12938-018-0562-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 09/17/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Irreversible electroporation (IRE) therapy relies on pulsed electric fields to non-thermally ablate cancerous tissue. Methods for evaluating IRE ablation in situ are critical to assessing treatment outcome. Analyzing changes in tissue impedance caused by electroporation has been proposed as a method for quantifying IRE ablation. In this paper, we assess the hypothesis that irreversible electroporation ablation outcome can be monitored using the impedance change measured by the electrode pairs not in use, getting more information about the ablation size in different directions. METHODS Using a square four-electrode configuration, the two diagonal electrodes were used to electroporate potato tissue. Next, the impedance changes, before and after treatment, were measured from different electrode pairs and the impedance information was extracted by fitting the data to an equivalent circuit model. Finally, we correlated the change of impedance from various electrode pairs to the ablation geometry through the use of fitted functions; then these functions were used to predict the ablation size and compared to the numerical simulation results. RESULTS The change in impedance from the electrodes used to apply pulses is larger and has higher deviation than the other electrode pairs. The ablation size and the change in resistance in the circuit model correlate with various linear functions. The coefficients of determination for the three functions are 0.8121, 0.8188 and 0.8691, respectively, showing satisfactory agreement. The functions can well predict the ablation size under different pulse numbers, and in some directions it did even better than the numerical simulation method, which used different electric field thresholds for different pulse numbers. CONCLUSIONS The relative change in tissue impedance measured from the non-energized electrodes can be used to assess ablation size during treatment with IRE according to linear functions.
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Affiliation(s)
- Yajun Zhao
- State Key Laboratory of Power Transmission Equipment and System Security and New Technology, School of Electrical Engineering, Chongqing University, No. 174 Shazhengjie, Shapingba District, Chongqing, 400044, China.,Department of Biomedical Engineering and Mechanics, Virginia Tech, 329 ICTAS Stanger St (0298), Blacksburg, VA, 24061, USA
| | - Hongmei Liu
- State Key Laboratory of Power Transmission Equipment and System Security and New Technology, School of Electrical Engineering, Chongqing University, No. 174 Shazhengjie, Shapingba District, Chongqing, 400044, China
| | - Suyashree P Bhonsle
- Department of Biomedical Engineering and Mechanics, Virginia Tech, 329 ICTAS Stanger St (0298), Blacksburg, VA, 24061, USA
| | - Yilin Wang
- State Key Laboratory of Power Transmission Equipment and System Security and New Technology, School of Electrical Engineering, Chongqing University, No. 174 Shazhengjie, Shapingba District, Chongqing, 400044, China
| | - Rafael V Davalos
- Department of Biomedical Engineering and Mechanics, Virginia Tech, 329 ICTAS Stanger St (0298), Blacksburg, VA, 24061, USA.
| | - Chenguo Yao
- State Key Laboratory of Power Transmission Equipment and System Security and New Technology, School of Electrical Engineering, Chongqing University, No. 174 Shazhengjie, Shapingba District, Chongqing, 400044, China.
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