Browsing by Author "Debinski, Waldemar"

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    Advancements in the Treatment of Malignant Gliomas and Other Intracranial Disorders With Electroporation-Based Therapies
    Lorenzo, Melvin Florencio (Virginia Tech, 2021-04-19)
    The most common and aggressive malignant brain tumor, glioblastoma (GBM), demonstrates on average a 5-year survival rate of only 6.8%. Difficulties arising in the treatment of GBM include the inability of large molecular agents to permeate through the blood-brain barrier (BBB); migration of highly invasive GBM cells beyond the solid tumor margin; and gross, macroscopic intratumor heterogeneity. These characteristics complicate treatment of GBM with standard of care, resulting in abysmal prognosis. Electroporation-based therapies have emerged as attractive alternates to standard of care, demonstrating favorable outcomes in a variety of tumors. Notably, irreversible electroporation (IRE) has been used for BBB disruption and nonthermal ablation of intracranial tumor tissues. Despite promising results, IRE can cause unintended muscle contractions and is susceptible to electrical heterogeneities. Second generation High-frequency IRE (H-FIRE) utilizes bursts of bipolar pulsed electric fields on the order of the cell charging time constant (~1 μs) to ablate tissue while reducing nerve excitation, muscle contraction, and is far less prone to differences in electrical heterogeneities. Throughout my dissertation, I discuss investigations of H-FIRE for the treatment of malignant gliomas and other intracranial disorders. To advance the versatility, usability, and understanding of H-FIRE for intracranial applications, my PhD thesis focuses on: (1) characterizing H-FIRE-mediated BBB disruption effects in an in vivo healthy rodent model; (2) the creation of a novel, real-time impedance spectroscopy technique (Fourier Analysis SpecTroscopy, FAST) using waveforms compatible with existing H-FIRE pulse generators; (3) development of FAST as an in situ technique to monitor ablation growth and to determine patient-specific ablation endpoints; (4) conducting a preliminary efficacy study of H-FIRE ablation in an orthotopic F98 rodent glioma model; and (5) establishing the feasibility of MRI-guided H-FIRE for the ablation malignant gliomas in a spontaneous canine glioma model. The culmination of this thesis advances our understanding of H-FIRE in intracranial tissues, as well as develops a novel, intraoperative impedance spectroscopy technique towards determining patient-specific ablation endpoints for intracranial H-FIRE procedures.
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    Canine Butterfly Glioblastomas: a Neuroradiological Review
    Rossmeisl, John H. Jr.; Clapp, Kemba; Pancotto, Theresa E.; Emch, Samantha; Robertson, John L.; Debinski, Waldemar (Frontiers, 2016-05-19)
    In humans, high-grade gliomas may infiltrate across the corpus callosum resulting in bihemispheric lesions that may have symmetrical, winged-like appearances. This particular tumor manifestation has been coined a “butterfly” glioma (BG). While canine and human gliomas share many neuroradiological and pathological features, the BG morphology has not been previously reported in dogs. Here, we describe the magnetic resonance imaging (MRI) characteristics of BG in three dogs and review the potential differential diagnoses based on neuroimaging findings. All dogs presented for generalized seizures and interictal neurological deficits referable to multifocal or diffuse forebrain disease. MRI examinations revealed asymmetrical (2/3) or symmetrical (1/3), bihemispheric intra-axial mass lesions that predominantly affected the frontoparietal lobes that were associated with extensive perilesional edema, and involvement of the corpus callosum. The masses displayed heterogeneous T1, T2, and fluid-attenuated inversion recovery signal intensities, variable contrast enhancement (2/3), and mass effect. All tumors demonstrated classical histopathological features of glioblastoma multiforme (GBM), including glial cell pseudopalisading, serpentine necrosis, microvascular proliferation as well as invasion of the corpus callosum by neoplastic astrocytes. Although rare, GBM should be considered a differential diagnosis in dogs with an MRI evidence of asymmetric or symmetric bilateral, intra-axial cerebral mass lesions with signal characteristics compatible with glioma.
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    Characterization of Ablation Thresholds for 3D-Cultured Patient-Derived Glioma Stem Cells in Response to High-Frequency Irreversible Electroporation
    Ivey, J. W.; Wasson, E. M.; Alinezhadbalalami, N.; Kanitkar, A.; Debinski, Waldemar; Sheng, Z.; Davalos, Rafael V.; Verbridge, Scott S. (American Association for the Advancement of Science, 2019-04-28)
    High-frequency irreversible electroporation (H-FIRE) is a technique that uses pulsed electric fields that have been shown to ablate malignant cells. In order to evaluate the clinical potential of H-FIRE to treat glioblastoma (GBM), a primary brain tumor, we have studied the effects of high-frequency waveforms on therapy-resistant glioma stem-like cell (GSC) populations. We demonstrate that patient-derived GSCs are more susceptible to H-FIRE damage than primary normal astrocytes. This selectivity presents an opportunity for a degree of malignant cell targeting as bulk tumor cells and tumor stem cells are seen to exhibit similar lethal electric field thresholds, significantly lower than that of healthy astrocytes. However, neural stem cell (NSC) populations also exhibit a similar sensitivity to these pulses. This observation may suggest that different considerations be taken when applying these therapies in younger versus older patients, where the importance of preserving NSC populations may impose different restrictions on use.We also demonstrate variability in threshold among the three patient-derived GSC lines studied, suggesting the need for personalized cell-specific characterization in the development of potential clinical procedures. Future work may provide further useful insights regarding this patient-dependent variability observed that could inform targeted and personalized treatment.
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    Combinatorial Treatments and Technologies for Safe and Effective Targeting of Malignant Gliomas Using High-Frequency Irreversible Electroporation.
    Campelo, Sabrina Nicole (Virginia Tech, 2023-12-21)
    Glioblastoma Multiforme (GBM) is a highly aggressive and prevalent brain tumor with an average 5-year survival rate of approximately 6.9%. Its complex pathophysiology, characterized by the capacity to invade surrounding tissues beyond the visible tumor margin, intratumor heterogeneity, hypoxic core, and the presence of the blood-brain barrier (BBB) that restricts the penetration of large therapeutic agents, all pose formidable challenges for effective therapeutic intervention. The standard of care for GBM has thus far exhibited limited success, and patients often face a poor prognosis. Electroporation-based therapies, such as irreversible electroporation (IRE), have emerged as promising alternatives to conventional treatments. By utilizing high amplitude pulsed electric fields, IRE is able to permeabilize cells, disrupt the BBB, and induce non thermal ablation of soft tissues. However, IRE is oftentimes accompanied by undesirable secondary effects such as muscle contractions, complex anesthetic protocols, and susceptibility to electrical heterogeneities, which have impeded its clinical translation. To address these limitations, high-frequency IRE (H-FIRE) was developed. H-FIRE employs short bursts of bipolar pulses, similar in duration to the cell charging time constant, enabling the desired tissue ablation while minimizing nerve excitation and muscle contractions. Additionally, H-FIRE reduces susceptibility to electrical heterogeneities, allowing for more predictable treatment volumes, thus enhancing the feasibility of clinical translation. This dissertation investigates H-FIRE for targeting malignant gliomas while looking into improved efficacy when administering the therapy in conjunction with other treatment forms and technologies. Specifically, the presented work focuses on several key areas: (1) determining the effect of pulsing protocol and geometric configuration selection on the biological outcomes from electroporation; (2) using a tumor bearing rodent glioma model to evaluate the effects of H-FIRE as a standalone therapy and as a combinatorial therapy with liposomal doxorubicin; (3) investigating the effects of waveform shape on biological outcomes; (4) utilizing real-time Fourier Analysis SpecTroscopy (FAST) to accurately model rises in temperature during treatment; and (5) modifying real-time FAST methods to determine treatment endpoints for safe and effective ablation volumes.
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    Comparison of linear and volumetric criteria for the determination of therapeutic response in dogs with intracranial gliomas
    Garcia Mora, Josefa Karina; Robertson, John L.; Hsu, Fang-Chi; Shinn, Richard Levon; Larson, Martha M.; Rylander, Christopher G.; Whitlow, Christopher T.; Debinski, Waldemar; Davalos, Rafael V.; Daniel, Gregory B.; Rossmeisl, John H. Jr. (Wiley, 2022-05)
    Background: Brain tumor therapeutic responses can be quantified from magnetic resonance images (MRI) using 1- (1D) and 2-dimensional (2D) linear and volumetric methods, but few studies in dogs compare these techniques. Hypotheses: Linear methods will be obtained faster, but have less agreement than volumetric measurements. Therapeutic response agreement will be highest with the total T2W tumor volumetric (TTV) method. Therapeutic response at 6-weeks will correlate with overall survival (OS). Animals: Forty-six dogs with intracranial gliomas. Methods: Prospective study. Three raters measured tumors using 1D and 2D linear, TTV, and contrast-enhancing volumetric (CEV) techniques on 143 brain MRI to determine agreement between methods, define therapeutic responses, and assess relations with OS. Results: Raters performed 1D the fastest (2.9 ± 0.57 minutes) and CEV slowest (17.8 ± 6.2 minutes). Inter- and intraobserver agreements were excellent (intraclass correlations ≥.91) across methods. Correlations between linear (1D vs 2D; ρ >.91) and volumetric (TTV vs CEV; ρ >.73) methods were stronger than linear to volumetric comparisons (ρ range,.26-.59). Incorporating clinical and imaging data resulted in fewer discordant therapeutic responses across methods. Dogs having partial tumor responses at 6 weeks had a lower death hazard than dogs with stable or progressive disease when assessed using 2D, CEV, and TTV (hazard ration 2.1; 95% confidence interval, 1.22-3.63; P =.008). Conclusions and Clinical Importance: One-dimensional, 2D, CEV, and TTV are comparable for determining therapeutic response. Given the simplicity, universal applicability, and superior performance of the TTV, we recommend its use to standardize glioma therapeutic response criteria.
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    Diagnostic accuracy of stereotactic brain biopsy for intracranial neoplasia in dogs: Comparison of biopsy, surgical resection, and necropsy specimens
    Kani, Yukitaka; Cecere, Thomas E.; Lahmers, Kevin K.; LeRoith, Tanya; Zimmerman, Kurt L.; Isom, Scott; Hsu, Fang-Chi; Debinski, Waldemar; Robertson, John L.; Rossmeisl, John H. Jr. (American College of Veterinary Internal Medicine, 2019-05)
    Background Stereotactic brain biopsy (SBB) is a technique that allows for definitive diagnosis of brain lesions. Little information is available regarding the diagnostic utility of SBB in dogs with intracranial diseases. Objective To investigate the diagnostic accuracy (DA) of SBB in dogs with brain tumors. Animals Thirty-one client-owned dogs that underwent SBB followed by surgical resection or necropsy examinations. Methods Retrospective observational study. Two pathologists blinded to SBB and reference standard diagnoses reviewed histologic specimens and typed and graded tumors according to World Health Organization and revised canine glioma classification criteria. Agreement between tumor type and grade from SBB were compared to reference standards and assessed using kappa statistics. Patient and technical factors associated with agreement also were examined. Results Stereotactic brain biopsy specimens were obtained from 24 dogs with gliomas and 7 with meningiomas. Tumor type agreement between SBB and the reference standard was observed in 30/31 cases (kappa = 0.95). Diagnostic concordance was perfect for meningiomas. Grade agreement among gliomas was observed in 18/23 cases (kappa = 0.47). Stereotactic brain biopsy underrepresented the reference standard glioma grade in cases with disagreement. The DA of SBB was 81%, with agreement noted in 56/69 biopsy samples. Smaller tumors and fewer SBB specimens obtained were significantly associated with diagnostic discordance. Conclusions and Clinical Importance The DA of SBB readily allows for the diagnosis of common brain tumors in dogs. Although glioma grade discordance was frequent, diagnoses obtained from SBB are sufficient to currently inform therapeutic decisions. Multiple SBB specimens should be collected to maximize DA.
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    Expression and activity of the urokinase plasminogen activator system in canine primary brain tumors
    Rossmeisl, John H. Jr.; Hall-Manning, Kelli; King, Jamie N.; Davalos, Rafael V.; Debinski, Waldemar; Elankumaran, Subbiah (Dove Press, 2017-04-12)
    Background: The expression of the urokinase plasminogen activator receptor (uPAR), a glycosylphosphatidylinositol-anchored protein family member, and the activity of its ligand, urokinase-type plasminogen activator (uPA), have been associated with the invasive and metastatic potentials of a variety of human brain tumors through their regulation of extracellular matrix degradation. Domesticated dogs develop naturally occurring brain tumors that share many clinical, phenotypic, molecular, and genetic features with their human counterparts, which has prompted the use of the dogs with spontaneous brain tumors as models to expedite the translation of novel brain tumor therapeutics to humans. There is currently little known regarding the role of the uPA system in canine brain tumorigenesis. The objective of this study was to characterize the expression of uPAR and the activity of uPA in canine brain tumors as justification for the development of uPAR-targeted brain tumor therapeutics in dogs. Methods: We investigated the expression of uPAR in 37 primary canine brain tumors using immunohistochemistry, Western blotting, real-time quantitative polymerase chain reaction analyses, and by the assay of the activity of uPA using casein–plasminogen zymography. Results: Expression of uPAR was observed in multiple tumoral microenvironmental niches, including neoplastic cells, stroma, and the vasculature of canine brain tumors. Relative to normal brain tissues, uPAR protein and mRNA expression were significantly greater in canine meningiomas, gliomas, and choroid plexus tumors. Increased activity of uPA was documented in all tumor types. Conclusions: uPAR is overexpressed and uPA activity increased in canine meningiomas, gliomas, and choroid plexus tumors. This study illustrates the potential of uPAR/uPA molecularly targeted approaches for canine brain tumor therapeutics and reinforces the translational significance of canines with spontaneous brain tumors as models for human disease.
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    Frame-Based Stereotactic Biopsy of Canine Brain Masses: Technique and Clinical Results in 26 Cases
    Rossmeisl, John H. Jr.; Andriani, Rudy T.; Cecere, Thomas E.; Lahmers, Kevin K.; LeRoith, Tanya; Zimmerman, Kurt L.; Gibo, Denise M.; Debinski, Waldemar (2015)
    This report describes the methodology, diagnostic yield, and adverse events (AE) associated with frame-based stereotactic brain biopsies (FBSB) obtained from 26 dogs with solitary forebrain lesions. Medical records were reviewed from dogs that underwent FBSB using two stereotactic headframes designed for use in small animals and compatible with computed tomographic (CT) and magnetic resonance (MR) imaging. Stereotactic plans were generated from MR and CT images using commercial software, and FBSB performed both with (14/26) and without intraoperative image guidance. Records were reviewed for diagnostic yield, defined as the proportion of biopsies producing a specific neuropathological diagnosis, AE associated with FBSB, and risk factors for the development of AE. Postprocedural AE were evaluated in 19/26 dogs that did not proceed to a therapeutic intervention immediately following biopsy. Biopsy targets included intra-axial telencephalic masses (24/26), one intra-axial diencephalic mass, and one extra-axial parasellar mass. The median target volume was 1.99 cm(3). No differences in patient, lesion, or outcome variables were observed between the two headframe systems used or between FBSB performed with or without intraoperative CT guidance. The diagnostic yield of FBSB was 94.6%. Needle placement error was a significant risk factor associated with procurement of non-diagnostic biopsy specimens. Gliomas were diagnosed in 24/26 dogs, and meningioma and granulomatous meningoencephalitis in 1 dog each. AE directly related to FBSB were observed in a total of 7/26 (27%) of dogs. Biopsy-associated clinical morbidity, manifesting as seizures and transient neurological deterioration, occurred in 3/19 (16%) of dogs. The case fatality rate was 5.2% (1/19 dogs), with death attributable to intracranial hemorrhage. FBSB using the described apparatus was relatively safe and effective at providing neuropathological diagnoses in dogs with focal forebrain lesions.
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    Invited Review-Neuroimaging Response Assessment Criteria for Brain Tumors in Veterinary Patients
    Rossmeisl, John H. Jr.; Garcia, Paulo A.; Daniel, Gregory B.; Bourland, John Daniel; Debinski, Waldemar; Dervisis, Nikolaos G.; Klahn, Shawna L. (Wiley-Blackwell, 2014-03-01)
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    New Agents for Targeting of IL-13RA2 Expressed in Primary Human and Canine Brain Tumors
    Debinski, Waldemar; Dickinson, Peter J.; Rossmeisl, John H. Jr.; Robertson, John L.; Gibo, Denise M. (PLOS, 2013-10-16)
    Interleukin 13 receptor alpha 2 (IL-13RA2) is over-expressed in a vast majority of human patients with high-grade astrocytomas like glioblastoma. Spontaneous astrocytomas in dogs resemble human disease and have been proposed as translational model system for investigation of novel therapeutic strategies for brain tumors. We have generated reagents for both detection and therapeutic targeting of IL-13RA2 in human and canine brain tumors. Peptides from three different regions of IL-13RA2 with 100% sequence identity between human and canine receptors were used as immunogens for generation of monoclonal antibodies. Recombinant canine mutant IL-13 (canIL-13.E13K) and canIL-13.E13K based cytotoxin were also produced. The antibodies were examined for their immunoreactivities in western blots, immunohistochemistry, immunofluorescence and cell binding assays using human and canine tumor specimen sections, tissue lysates and established cell lines; the cytotoxin was tested for specific cell killing. Several isolated MAbs were immunoreactive to IL-13RA2 in western blots of cell and tissue lysates from glioblastomas from both human and canine patients. Human and canine astrocytomas and oligodendrogliomas were also positive for IL-13RA2 to various degrees. Interestingly, both human and canine meningiomas also exhibited strong reactivity. Normal human and canine brain samples were virtually negative for IL-13RA2 using the newly generated MAbs. MAb 1E10B9 uniquely worked on tissue specimens and western blots, bound live cells and was internalized in GBM cells over-expressing IL-13RA2. The canIL-13.E13K cytotoxin was very potent and specific in killing canine GBM cell lines. Thus, we have obtained several monoclonal antibodies against IL-13RA2 cross-reacting with human and canine receptors. In addition to GBM, other brain tumors, such as high grade oligodendrogliomas, meningiomas and canine choroid plexus papillomas, appear to express the receptor at high levels and thus may be appropriate candidates for IL-13RA2-targeted imaging/therapies. Canine spontaneous primary brain tumors represent an excellent translational model for human counterparts.
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    Phase I trial of convection-enhanced delivery of IL13RA2 and EPHA2 receptor targeted cytotoxins in dogs with spontaneous intracranial gliomas
    Rossmeisl, John H. Jr.; Herpai, Denise; Quigley, Mindy; Cecere, Thomas E.; Robertson, John L.; D'Agostino, Ralph B.; Hinckley, Jonathan; Tatter, Stephen B.; Dickinson, Peter J.; Debinski, Waldemar (2021-03)
    Background. The interleukin-13 receptor alpha 2 (IL13RA2) and ephrin type A receptor 2 (EPHA2) are attractive therapeutic targets, being expressed in similar to 90% of canine and human gliomas, and absent in normal brain. Clinical trials using an earlier generation IL-13 based cytotoxin showed encouraging clinical effects in human glioma, but met with technical barriers associated with the convection-enhanced delivery (CED) method. In this study, IL-13 mutant and ephrin A1 (EFNA1)-based bacterial cytotoxins targeted to IL13RA2 and EPHA2 receptors, respectively, were administered locoregionally by CED to dogs with intracranial gliomas to evaluate their safety and preliminary efficacy. Methods. In this phase I, 3 + 3 dose escalation trial, cytotoxins were infused by CED in 17 dogs with gliomas expressing IL13RA2 or EPHA2 receptors. CED was performed using a shape-fitting therapeutic planning algorithm, reflux-preventing catheters, and real-time intraoperative MRI monitoring. The primary endpoint was to determine the maximum tolerated dose of the cytotoxic cocktail in dogs with gliomas. Results. Consistent intratumoral delivery of the cytotoxic cocktail was achieved, with a median target coverage of 70% (range, 40-94%). Cytotoxins were well tolerated over a dose range of 0.012-1.278 mu g/mL delivered to the target volume (median, 0.099 mu g/mL), with no dose limiting toxicities observed. Objective tumor responses, up to 94% tumor volume reduction, were observed in 50% (8/16) of dogs, including at least one dog in each dosing cohort >0.05 mu g/mL. Conclusions. This study provides preclinical data fundamental to the translation of this multireceptor targeted therapeutic approach to the human clinic.