Primary intraparenchymal brain tumors, including astrocytomas, glioblastomas, and oligodendrogliomas, collectively comprise approximately 35% of all primary brain tumors in dogs. The prognosis for dogs with any of these tumor types is generally guarded to poor. The median survival time regardless of treatment type is approximately 230 days. Due to numerous challenges associated with diagnosing, grading, treating, and reporting survival outcomes, there is currently no gold standard therapy for these tumors in dogs. Additionally, the similarities between canine and human primary intraparenchymal brain tumors lend translational opportunity to the development of novel treatment delivery systems for canine brain tumors. Glial tumors invade and migrate along white matter tracts and blood vessels, which is a characteristic that can be exploited. Catheters lined with nanofiber particles have been developed to structurally mimic these conduits. The conformation guides tumor cells away from the tumor site to an extracranial reservoir. In this study we describe the techniques associated with stereotactically-guided implantation of nanofiber-lined catheters in dogs with naturally occurring and histopathologically confirmed astrocytomas and oligodendrogliomas. The purpose of this study was to evaluate the safety and feasibility of stereotactically-guided insertion of nanofiber catheters and to confirm tumor cell migration along internal catheter walls. Nanofiber catheter placement technique was evaluated in four client-owned dogs with MRI-confirmed prosencephalic neoplasms that had imaging characteristics consistent with gliomas. A frameless surgical navigation system (StealthStation Surgical Navigation System; Medtronic) was used to guide the catheters (FiberCath Tumor Extraction Device; NeuroLab) through a small, standard rostrotentorial craniectomy window into the tumor center. Intra-tumor catheter placement was confirmed with post-operative MRI evaluation. One month post-operatively, the reservoirs were extracted and replaced. The extracted reservoirs were histologically examined for evidence of intraluminal tumor cells. The surgical outcomes of all dogs were good and microscopic evaluation of the extracted catheters confirmed intraluminal tumor cells. Although this study is small and cannot prove treatment efficacy, these findings support our hypotheses that stereotactic guidance of nanofiber catheters is safe, feasible, and encourages tumor cell migration out of the cranial cavity. This is the first stage in a large clinical trial that ultimately aims to evaluate the safety and efficacy of nanofiber catheters in the treatment of canine brain tumors.
Neurology and Neurosurgery Resident
University of Georgia
Susan Arnold is currently a Neurology and Neurosurgery Resident at the University of Georgia College of Veterinary Medicine. She graduated from the University of Wisconsin School of Veterinary Medicine in 2014 and completed a year in small animal general practice prior to completing a small animal medicine and surgery rotating internship at the University of Minnesota College of Veterinary Medicine in 2016. Her research interests include investigating novel brain tumor treatments and spinal cord injury treatments.
Thursday, June 14
10:15 AM – 10:30 AM
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