High-Frequency Irreversible Electroporation for Intracranial Meningioma: A Feasibility Study in a Spontaneous Canine Tumor Model.

Abstract

High-frequency irreversible electroporation is a nonthermal method of tissue ablation that uses bursts of 0.5- to 2.0-microsecond bipolar electric pulses to permeabilize cell membranes and induce cell death. High-frequency irreversible electroporation has potential advantages for use in neurosurgery, including the ability to deliver pulses without inducing muscle contraction, inherent selectivity against malignant cells, and the capability of simultaneously opening the blood–brain barrier surrounding regions of ablation. Our objective was to determine whether high-frequency irreversible electroporation pulses capable of tumor ablation could be delivered to dogs with intracranial meningiomas. Three dogs with intracranial meningiomas were treated. Patient-specific treatment plans were generated using magnetic resonance imaging-based tissue segmentation, volumetric meshing, and finite element modeling. Following tumor biopsy, high-frequency irreversible electroporation pulses were stereotactically delivered in situ followed by tumor resection and morphologic and volumetric assessments of ablations. Clinical evaluations of treatment included pre- and posttreatment clinical, laboratory, and magnetic resonance imaging examinations and adverse event monitoring for 2 weeks posttreatment. High-frequency irreversible electroporation pulses were administered successfully in all patients. No adverse events directly attributable to high-frequency irreversible electroporation were observed. Individual ablations resulted in volumes of tumor necrosis ranging from 0.25 to 1.29 cm3. In one dog, nonuniform ablations were observed, with viable tumor cells remaining around foci of intratumoral mineralization. In conclusion, high-frequency irreversible electroporation pulses can be delivered to brain tumors, including areas adjacent to critical vasculature, and are capable of producing clinically relevant volumes of tumor ablation. Mineralization may complicate achievement of complete tumor ablation.