Experimental Characterization and Numerical Modeling of Tissue Electrical Conductivity during Pulsed Electric Fields for Irreversible Electroporation Treatment Planning

Neal, Robert E.; García, Paulo A.; Robertson, John L.; Davalos, Rafael V.

doi:10.1109/tbme.2012.2182994

Cited by 173 publications

(122 citation statements)

References 45 publications

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“…Our results were not entirely anticipated from the recent studies that have attempted to characterize electrical conductivity changes during IRE treatment in the kidney (11) and brain (32), including the use of finite element modeling (33). For the kidney, Neal et al noted (11) that electrical current values reached a plateau; whereas, we observed a decrease in current during the course of IRE treatment of the kidney.…”

Section: Experimental Studies: Irreversible Electroporation Ben-davidcontrasting

confidence: 69%

Irreversible Electroporation: Treatment Effect is Susceptible to Local Environment and Tissue Properties

Ben-David¹,

Ahmed²,

Faroja³

et al. 2013

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).q RSNA, 2013 Purpose:To study the effects of the surrounding electrical microenvironment and local tissue parameters on the electrical parameters and outcome of irreversible electroporation (IRE) ablation in porcine muscle, kidney, and liver tissue. Materials and Methods:Animal Care and Use Committee approval was obtained, and National Institutes of Health guidelines were followed. IRE ablation (n = 90) was applied in muscle (n = 44), kidney (n = 28), and liver (n = 18) tissue in 18 pigs. Two electrodes with tip exposure of 1.5-2 cm were used at varying voltages (1500-3000 V), pulse repetitions (n = 70-100), pulse length (70-100 µsec), and electrode spacing (1.5-2 cm). In muscle tissue, electrodes were placed exactly parallel, in plane, or perpendicular to paraspinal muscle fibers; in kidney tissue, in the cortex or adjacent to the renal medulla; and in liver tissue, with and without metallic or plastic plates placed 1-2 cm from electrodes. Ablation zones were determined at gross pathologic (90-120 minutes after IRE) and immunohistopathologic examination (6 hours after) for apoptosis and heat-shock protein markers. Multivariate analysis of variance with multiple comparisons and/or paired t tests and regression analysis were used for analysis. Results:Mean (6 standard deviation) ablation zones in muscle were 6.2 cm 6 0.3 3 4.2 cm 6 0.3 for parallel electrodes and 4.2 cm 6 0.8 3 3.0 cm 6 0.5 for in-plane application. Perpendicular orientation resulted in a cross-shaped zone. Orientation significantly affected IRE current applied (28.5-31.7A for parallel, 29.5-39.7A for perpendicular; P = .003). For kidney cortex, ovoid zones of 1.5 cm 6 0.1 3 0.5 cm 6 0.0 to 2.5 cm 6 0.1 3 1.3 cm 6 0.1 were seen. Placement of electrodes less than 5 mm from the medullary pyramids resulted in treatment effect arcing into the collecting system. For liver tissue, symmetric 2.7 cm 6 0.2 3 1.4 cm 6 0.3 coagulation areas were seen without the metallic plate but asymmetric coagulation was seen with the metallic plate. Conclusion:IRE treatment zones are sensitive to varying electrical conductivity in tissues. Electrode location, orientation, and heterogeneities in local environment must be considered in planning ablation treatment.q RSNA, 2013 Supplemental material: http://radiology.rsna.org/lookup /suppl

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Section: Experimental Studies: Irreversible Electroporation Ben-davidcontrasting

confidence: 69%

Irreversible Electroporation: Treatment Effect is Susceptible to Local Environment and Tissue Properties

Ben-David¹,

Ahmed²,

Faroja³

et al. 2013

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“…2,18,[27][28][29][31][32][33][34][35] Figure 2 shows the model geometry, a parallelepiped (eg, sizes 5 Â 3.5 Â 3.5 cm 3 ) with 2 cylinders that simulate the stainless steel needles, 1.2 cm long and 0.5 mm diameter. The gray parallelepiped represents a homogeneous material characterized by the electrical resistivity of the tissue in this example is 5 Ωm (conductivity of 0.2 S/m).…”

Section: Computational Modelmentioning

confidence: 99%

Evaluation of the Electroporation Efficiency of a Grid Electrode for Electrochemotherapy

Ongaro

Campana

Mattei

et al. 2015

Technol Cancer Res Treat

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Electrochemotherapy (ECT) is a local anticancer treatment based on the combination of chemotherapy and short, tumorpermeabilizing, voltage pulses delivered using needle electrodes or plate electrodes. The application of ECT to large skin surface tumors is time consuming due to technical limitations of currently available voltage applicators. The availability of large pulse applicators with few and more spaced needle electrodes could be useful in the clinic, since they could allow managing large and spread tumors while limiting the duration and the invasiveness of the procedure. In this article, a grid electrode with 2-cm spaced needles has been studied by means of numerical models. The electroporation efficiency has been assessed on human osteosarcoma cell line MG63 cultured in monolayer. The computational results show the distribution of the electric field in a model of the treated tissue. These results are helpful to evaluate the effect of the needle distance on the electric field distribution. Furthermore, the in vitro tests showed that the grid electrode proposed is suitable to electropore, by a single application, a cell culture covering an area of 55 cm 2 . In conclusion, our data might represent substantial improvement in ECT in order to achieve a more homogeneous and time-saving treatment, with benefits for patients with cancer.

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“…Accounting for dynamic conductivity allows for more accurate representation of lesions created by IRE (57), and potentially H-FIRE. Incorporating changes in tissue conductivity can be achieved using a fitted Gompertz function (58). Alternatively, a sigmoid function can mimic changes in electrical conductivity due to electric field magnitude as well as temperature.…”

Section: Ire and H-fire Treatment Planningmentioning

confidence: 99%

Maximizing Local Access to Therapeutic Deliveries in Glioblastoma. Part III: Irreversible Electroporation and High-Frequency Irreversible Electroporation for the Eradication of Glioblastoma

2017

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Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults. Approximately 9180 primary GBM tumors are diagnosed in the United States each year, in which median survival is up to 16 months. GBM eludes and resists typical cancer treatments due to the presence of infiltrative cells beyond the solid tumor margin, heterogeneity within the tumor microenvironment, and protection from the blood-brain barrier. Conventional treatments for GBM, such as surgical resection, radiotherapy, and chemotherapy, have shown limited efficacy;IRE and H-FIRE for the Eradication of GBM 374 therefore, alternate treatments are needed. Tumor chemoresistance and its proximity to critical structures make GBM a prime theoretical candidate for nonthermal ablation with irreversible electroporation (IRE) and high-frequency IRE (H-FIRE). IRE and H-FIRE are treatment modalities that utilize pulsed electric fields to permeabilize the cell membrane. Once the electric field magnitude exceeds a tissue-specific lethal threshold, cell death occurs. Benefits of IRE and H-FIRE therapy include, but are not limited to, the elimination of cytotoxic effects, sharp delineation from treated tissue and spared tissue, a nonthermal mechanism of ablation, and sparing of nerves and major blood vessels. Preclinical studies have confirmed the safety and efficacy of IRE and H-FIRE within their experimental scope. In this chapter, studies will be collected and information extrapolated to provide possible treatment regimens for use in high-grade gliomas, specifically in GBM.

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Experimental Characterization and Numerical Modeling of Tissue Electrical Conductivity during Pulsed Electric Fields for Irreversible Electroporation Treatment Planning

Cited by 173 publications

References 45 publications

Irreversible Electroporation: Treatment Effect is Susceptible to Local Environment and Tissue Properties

Irreversible Electroporation: Treatment Effect is Susceptible to Local Environment and Tissue Properties

Evaluation of the Electroporation Efficiency of a Grid Electrode for Electrochemotherapy

Maximizing Local Access to Therapeutic Deliveries in Glioblastoma. Part III: Irreversible Electroporation and High-Frequency Irreversible Electroporation for the Eradication of Glioblastoma

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