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Title: Planning Irreversible Electroporation in the Porcine Kidney: Are Numerical Simulations Reliable for Predicting Empiric Ablation Outcomes?

Abstract

PurposeNumerical simulations are used for treatment planning in clinical applications of irreversible electroporation (IRE) to determine ablation size and shape. To assess the reliability of simulations for treatment planning, we compared simulation results with empiric outcomes of renal IRE using computed tomography (CT) and histology in an animal model.MethodsThe ablation size and shape for six different IRE parameter sets (70–90 pulses, 2,000–2,700 V, 70–100 µs) for monopolar and bipolar electrodes was simulated using a numerical model. Employing these treatment parameters, 35 CT-guided IRE ablations were created in both kidneys of six pigs and followed up with CT immediately and after 24 h. Histopathology was analyzed from postablation day 1.ResultsAblation zones on CT measured 81 ± 18 % (day 0, p ≤ 0.05) and 115 ± 18 % (day 1, p ≤ 0.09) of the simulated size for monopolar electrodes, and 190 ± 33 % (day 0, p ≤ 0.001) and 234 ± 12 % (day 1, p ≤ 0.0001) for bipolar electrodes. Histopathology indicated smaller ablation zones than simulated (71 ± 41 %, p ≤ 0.047) and measured on CT (47 ± 16 %, p ≤ 0.005) with complete ablation of kidney parenchyma within the central zone and incomplete ablation in the periphery.ConclusionBoth numerical simulations for planning renal IRE and CT measurements may overestimate the size of ablation compared to histology, and ablation effects may be incomplete in the periphery.

Authors:
; ;  [1];  [2];  [3]; ; ;  [1];  [4];  [1]
  1. Memorial Sloan-Kettering Cancer Center, Interventional Radiology Service, Department of Radiology (United States)
  2. The Rockefeller University, Research Animal Resource Center, Memorial Sloan-Kettering Cancer Center, Weill Cornell Medical College (United States)
  3. The Rockefeller University, Laboratory of Comparative Pathology, Memorial Sloan-Kettering Cancer Center, Weill Cornell Medical College (United States)
  4. Memorial Sloan-Kettering Cancer Center, Urology Service, Department of Surgery (United States)
Publication Date:
OSTI Identifier:
22470098
Resource Type:
Journal Article
Resource Relation:
Journal Name: Cardiovascular and Interventional Radiology; Journal Volume: 38; Journal Issue: 1; Conference: IROS 2015: Interventional Radiological Olbert Symposium, Berlin (Germany), 15-17 Jan 2015; Other Information: Copyright (c) 2015 Springer Science+Business Media New York and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE); http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ABLATION; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; COMPUTERIZED TOMOGRAPHY; ELECTRODES; HISTOLOGY; KIDNEYS; PLANNING; RELIABILITY; SWINE

Citation Formats

Wimmer, Thomas, E-mail: thomas.wimmer@medunigraz.at, Srimathveeravalli, Govindarajan, Gutta, Narendra, Ezell, Paula C., Monette, Sebastien, Maybody, Majid, Erinjery, Joseph P., Durack, Jeremy C., Coleman, Jonathan A., and Solomon, Stephen B. Planning Irreversible Electroporation in the Porcine Kidney: Are Numerical Simulations Reliable for Predicting Empiric Ablation Outcomes?. United States: N. p., 2015. Web. doi:10.1007/S00270-014-0905-2.
Wimmer, Thomas, E-mail: thomas.wimmer@medunigraz.at, Srimathveeravalli, Govindarajan, Gutta, Narendra, Ezell, Paula C., Monette, Sebastien, Maybody, Majid, Erinjery, Joseph P., Durack, Jeremy C., Coleman, Jonathan A., & Solomon, Stephen B. Planning Irreversible Electroporation in the Porcine Kidney: Are Numerical Simulations Reliable for Predicting Empiric Ablation Outcomes?. United States. doi:10.1007/S00270-014-0905-2.
Wimmer, Thomas, E-mail: thomas.wimmer@medunigraz.at, Srimathveeravalli, Govindarajan, Gutta, Narendra, Ezell, Paula C., Monette, Sebastien, Maybody, Majid, Erinjery, Joseph P., Durack, Jeremy C., Coleman, Jonathan A., and Solomon, Stephen B. Sun . "Planning Irreversible Electroporation in the Porcine Kidney: Are Numerical Simulations Reliable for Predicting Empiric Ablation Outcomes?". United States. doi:10.1007/S00270-014-0905-2.
@article{osti_22470098,
title = {Planning Irreversible Electroporation in the Porcine Kidney: Are Numerical Simulations Reliable for Predicting Empiric Ablation Outcomes?},
author = {Wimmer, Thomas, E-mail: thomas.wimmer@medunigraz.at and Srimathveeravalli, Govindarajan and Gutta, Narendra and Ezell, Paula C. and Monette, Sebastien and Maybody, Majid and Erinjery, Joseph P. and Durack, Jeremy C. and Coleman, Jonathan A. and Solomon, Stephen B.},
abstractNote = {PurposeNumerical simulations are used for treatment planning in clinical applications of irreversible electroporation (IRE) to determine ablation size and shape. To assess the reliability of simulations for treatment planning, we compared simulation results with empiric outcomes of renal IRE using computed tomography (CT) and histology in an animal model.MethodsThe ablation size and shape for six different IRE parameter sets (70–90 pulses, 2,000–2,700 V, 70–100 µs) for monopolar and bipolar electrodes was simulated using a numerical model. Employing these treatment parameters, 35 CT-guided IRE ablations were created in both kidneys of six pigs and followed up with CT immediately and after 24 h. Histopathology was analyzed from postablation day 1.ResultsAblation zones on CT measured 81 ± 18 % (day 0, p ≤ 0.05) and 115 ± 18 % (day 1, p ≤ 0.09) of the simulated size for monopolar electrodes, and 190 ± 33 % (day 0, p ≤ 0.001) and 234 ± 12 % (day 1, p ≤ 0.0001) for bipolar electrodes. Histopathology indicated smaller ablation zones than simulated (71 ± 41 %, p ≤ 0.047) and measured on CT (47 ± 16 %, p ≤ 0.005) with complete ablation of kidney parenchyma within the central zone and incomplete ablation in the periphery.ConclusionBoth numerical simulations for planning renal IRE and CT measurements may overestimate the size of ablation compared to histology, and ablation effects may be incomplete in the periphery.},
doi = {10.1007/S00270-014-0905-2},
journal = {Cardiovascular and Interventional Radiology},
number = 1,
volume = 38,
place = {United States},
year = {Sun Feb 15 00:00:00 EST 2015},
month = {Sun Feb 15 00:00:00 EST 2015}
}
  • Objective: Irreversible electroporation (IRE) uses direct electrical pulses to create permanent 'pores' in cell membranes to cause cell death. In contrast to conventional modalities, IRE has a nonthermal mechanism of action. Our objective was to study the histopathological and imaging features of IRE in normal swine lung. Materials and Methods: Eleven female swine were studied for hyperacute (8 h), acute (24 h), subacute (96 h), and chronic (3 week) effects of IRE ablation in lung. Paired unipolar IRE applicators were placed under computed tomography (CT) guidance. Some applicators were deliberately positioned near bronchovascular structures. IRE pulse delivery was synchronized withmore » the cardiac rhythm only when ablation was performed within 2 cm of the heart. Contrast-enhanced CT scan was performed immediately before and after IRE and at 1 and 3 weeks after IRE ablation. Representative tissue was stained with hematoxylin and eosin for histopathology. Results: Twenty-five ablations were created: ten hyperacute, four acute, and three subacute ablations showed alveolar edema and necrosis with necrosis of bronchial, bronchiolar, and vascular epithelium. Bronchovascular architecture was maintained. Chronic ablations showed bronchiolitis obliterans and alveolar interstitial fibrosis. Immediate post-procedure CT images showed linear or patchy density along the applicator tract. At 1 week, there was consolidation that resolved partially or completely by 3 weeks. Pneumothorax requiring chest tube developed in two animals; no significant cardiac arrhythmias were noted. Conclusion: Our preliminary porcine study demonstrates the nonthermal and extracellular matrix sparing mechanism of action of IRE. IRE is a potential alternative to thermal ablative modalities.« less
  • Purpose: The nonthermal irreversible electroporation (NTIRE) is a novel nonthermal tissue ablation technique by local application of high-voltage current within microseconds leading to a delayed apoptosis. The purpose of this experimental study was the first angiographic evaluation of the acute damage of renal vascular structure in NTIRE. Methods: Results of conventional dynamic digital substraction angiography (DSA) and visualization of the terminal vascular bed of renal parenchyma by high-resolution X-ray in mammography technique were evaluated before, during, and after NTIRE of three isolated perfused porcine ex vivo kidneys. Results: In the dedicated investigation, no acute vascular destruction of the renal parenchymamore » and no dysfunction of the kidney perfusion model were observed during or after NTIRE. Conspicuous were concentric wave-like fluctuations of the DSA contrast agent simultaneous to the NTIRE pulses resulting from NTIRE pulse shock wave. Conclusion: The NTIRE offers an ablation method with no acute collateral vascular damage in angiographic evaluation.« less
  • PurposeTo evaluate the effect of previous transarterial iodized oil tissue marking (ITM) on technical parameters, three-dimensional (3D) computed tomographic (CT) rendering of the electroporation zone, and histopathology after CT-guided irreversible electroporation (IRE) in an acute porcine liver model as a potential strategy to improve IRE performance.MethodsAfter Ethics Committee approval was obtained, in five landrace pigs, two IREs of the right and left liver (RL and LL) were performed under CT guidance with identical electroporation parameters. Before IRE, transarterial marking of the LL was performed with iodized oil. Nonenhanced and contrast-enhanced CT examinations followed. One hour after IRE, animals were killedmore » and livers collected. Mean resulting voltage and amperage during IRE were assessed. For 3D CT rendering of the electroporation zone, parameters for size and shape were analyzed. Quantitative data were compared by the Mann–Whitney test. Histopathological differences were assessed.ResultsMean resulting voltage and amperage were 2,545.3 ± 66.0 V and 26.1 ± 1.8 A for RL, and 2,537.3 ± 69.0 V and 27.7 ± 1.8 A for LL without significant differences. Short axis, volume, and sphericity index were 16.5 ± 4.4 mm, 8.6 ± 3.2 cm{sup 3}, and 1.7 ± 0.3 for RL, and 18.2 ± 3.4 mm, 9.8 ± 3.8 cm{sup 3}, and 1.7 ± 0.3 for LL without significant differences. For RL and LL, the electroporation zone consisted of severely widened hepatic sinusoids containing erythrocytes and showed homogeneous apoptosis. For LL, iodized oil could be detected in the center and at the rim of the electroporation zone.ConclusionThere is no adverse effect of previous ITM on technical parameters, 3D CT rendering of the electroporation zone, and histopathology after CT-guided IRE of the liver.« less
  • No abstract prepared.
  • PurposeTo evaluate the chronological effects of irreversible electroporation (IRE) on large hilar bile ducts in an in vivo porcine model correlated with computed tomography (CT) cholangiography and histopathology.Materials and MethodsTwelve IRE zones were made along hilar bile ducts intraoperatively under ultrasound (US)-guidance in 11 pigs. Paired electrodes were placed either on opposing sides of the bile duct (straddle [STR]) or both on one side of the bile duct (one-sided [OSD]). The shortest electrode-to-duct distance was classified as periductal (≤2 mm) or nonperiductal (>2 mm). CT cholangiography and laboratory tests were performed before IRE and again at 2 days, 4 weeks, and 8 weeks after IRE.more » Degree of bile duct injury were graded as follows: grade 0 = no narrowing; grade 1 = ≤50 % duct narrowing; grade 2 = >50 % narrowing without proximal duct dilatation; grade 3 = grade 2 with proximal duct dilatation; and grade 4 = grade 3 with enzyme elevation. Pigs were selected for killing and histopathology at 2 days, 4, and 8 weeks.ResultsNonperiductal electrode placement produced no long-term strictures in 5 of 5 ducts. Periductal electrode placement produced mild narrowing in 6 of 7 ducts: 5 grade 1 and 1 grade 2. None showed increased enzymes. There was no significant difference between STR versus OSD electrode placement. Histopathology showed minor but relatively greater ductal mural changes in narrowed ducts.ConclusionIn the larger hilar ducts, long-term patency and mural integrity appear resistant to IRE damage with the energy deposition used, especially if the electrode is not immediately periductal in position.« less