Publications by authors named "Brian Toyota"

There is considerable variability in the management of diffuse low-grade gliomas (LGGs). To characterize treatment paradigms, a survey of Canadian neurosurgeons was performed with forty neurosurgeons responding. Their responses show that the management of patients with LGGs has evolved in the past decade and findings from the RTOG9802 trial have been integrated into the practice of Canadian neurosurgeons.

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Glioblastoma multiforme (GBM) is a rapidly progressive and deadly form of brain tumor with a median survival rate of ~15 months. GBMs are hard to treat and significantly affect the patient's physical and cognitive abilities and quality of life. Temozolomide (TMZ)-an alkylating agent that causes DNA damage-is the only chemotherapy choice for the treatment of GBM.

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Primary brain tumors including gliomas continue to pose significant management challenges to clinicians. While the presentation, the pathology, and the clinical course of these lesions are variable, the initial investigations are usually similar. Patients who are suspected to have a brain tumor will be assessed with computed tomography (CT) and magnetic resonance imaging (MRI).

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Effective management of brain and spine tumors relies on a multidisciplinary approach encompassing surgery, radiation, and systemic therapy. In the era of personalized oncology, the latter is complemented by various molecularly targeting agents. Precise identification of cellular targets for these drugs requires comprehensive profiling of the cancer genome coupled with an efficient analytic pipeline, leading to an informed decision on drug selection, prognosis, and confirmation of the original pathological diagnosis.

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Background: Stereotactic laser ablation (SLA) has demonstrated potential utility for a spectrum of difficult to treat neurosurgical pathologies in multiple small and/or retrospective single-institutional series. Here, we present the safety profile of SLA of intracranial lesions from the Laser Ablation of Abnormal Neurological Tissue using Robotic NeuroBlate System (LAANTERN; Monteris Medical) multi-institutional, international prospective observational registry.

Objective: To determine the procedural safety of SLA for intracranial lesions.

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Objective: To determine whether dose painting with volumetric modulated arc therapy for high-grade gliomas using 3,4-dihydroxy-6-[F]fluoro-l-phenylalanine (F-FDOPA) positron emission tomography (PET) could achieve dose-escalated coverage of biological target volumes (BTVs) without increasing the dose to cranial organs at risk (OARs).

Methods: 10 patients with high-grade gliomas underwent CT, MRI, and F-FDOPA PET/CT images for post-operative radiation therapy planning. Two volumetric modulated arc therapy plans were retrospectively generated for each patient: a conventional plan with 60 Gy in 30 fractions to the planning target volume delineated on MRI and a dose-escalated plan with a maximum dose of 80 Gy in 30 fractions to BTVs.

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Background: As with other specialties, Royal College of Physicians and Surgeons of Canada (RCPSC) trainees in Neurosurgery have anecdotally had challenges securing full-time employment. This study presents the employment status, research pursuits, and fellowship choices of neurosurgery trainees in Canadian programs.

Methods: RCPSC neurosurgery trainees (n = 143) who began their residency training between 1998 and 2008 were included in this study.

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Treatment of glioblastoma (GBM), as the most lethal type of brain tumor, still remains a major challenge despite the various therapeutic approaches developed over the recent decades. GBM is considered as one of the most therapy-resistant human tumors. Treatment with temozolomide (TMZ) chemotherapy and radiotherapy in GBM patients has led to 30% of two-year survival rate (American Brain Tumor Association), representing a demanding field to develop more effective therapeutic strategies.

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Objective: The Resident Activity Tracker Evaluation (RATE) is a prospective observational study evaluating the impact of work hours, sleep and physical activity on resident well-being, burnout and job satisfaction.

Background: Physician burnout is common and its incidence is increasing. The impact of work hours and sleep on resident well-being and burnout remains elusive.

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Background: Glioblastoma (GBM) is the most common malignant primary brain cancer in adults. Recent efforts have elucidated genetic features of tumor cells and thus enhanced our knowledge of GBM pathophysiology. The most recent clinical trials report median overall survival between 14 and 20 months.

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Background: Stereotactic laser ablation (SLA), also termed laser interstitial thermal therapy, is a minimally invasive procedure that is increasingly used in neurosurgery. We wished to examine how and whether SLA is changing the landscape of treatment options for neurosurgical patients.

Methods: Patients undergoing stereotactic laser ablation were prospectively enrolled in the Laser Ablation of Abnormal Neurological Tissue (LAANTERN) registry.

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Despite advances in neurosurgical techniques and radio-/chemotherapy, the treatment of brain tumors remains a challenge. This is particularly true for the most frequent and fatal adult brain tumor, glioblastoma (GB). Upon diagnosis, the average survival time of GB patients remains only approximately 15months.

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Unlabelled: Background Traditionally, the delivery of dedicated neurocritical care (NCC) occurs in distinct NCC units and is associated with improved outcomes. Institution-specific logistical challenges pose barriers to the development of distinct NCC units; therefore, we developed a consultancy NCC service coupled with the implementation of invasive multimodal neuromonitoring, within a medical-surgical intensive care unit. Our objective was to evaluate the effect of a consultancy NCC program on neurologic outcomes in severe traumatic brain injury patients.

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Purpose: Although recruitment maneuvers have been advocated as part of a lung protective ventilation strategy, their effects on cerebral physiology during elective neurosurgery are unknown. Our objectives were to determine the effects of an alveolar recruitment maneuver on subdural pressure (SDP), brain relaxation score (BRS), and cerebral perfusion pressure among patients undergoing supratentorial tumour resection.

Methods: In this prospective crossover study, patients scheduled for resection of a supratentorial brain tumour were randomized to undergo either a recruitment maneuver (30 cm of water for 30 sec) or a "sham" maneuver (5 cm of water for 30 sec), followed by the alternative intervention after a 90-sec equilibration period.

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Glioneuronal tumors constitute a histologically diverse group of primary central nervous system neoplasms that are typically slow-growing and managed conservatively. Genetic alterations associated with glioneuronal tumors include mutations and oncogenic fusions. To further characterize this group of tumors, we collected a cohort of 26 glioneuronal tumors and performed in-depth genomic analysis.

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Introduction Determining the full extent of gliomas during radiotherapy planning can be challenging with conventional T1 and T2 magnetic resonance imaging (MRI). The purpose of this study was to develop a method to automatically calculate differences in the fractional anisotropy (FA) and mean diffusivity (MD) values in target volumes obtained with diffusion tensor imaging (DTI) by comparing with values from anatomically homologous voxels on the contralateral side of the brain. Methods Seven patients with a histologically confirmed glioma underwent postoperative radiotherapy planning with 1.

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Objective To describe our experience with stereotactic radiosurgery and its efficacy on growing tumors, and then to compare this result with the natural history of a similar cohort of non-radiation-treated lesions. Study Design A retrospective chart review and cohort comparison. Methods The long-term control rates of patients having undergone radiosurgery were collected and calculated, and this population was then compared with a group of untreated patients from the same period of time with growing lesions.

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Background: To examine stereotactic radiosurgery (SRS) following whole brain radiotherapy for metastases in eloquent, central brain locations: brainstem, thalamus, and basal ganglia.

Methods: We conducted a retrospective review of patients with metastases in eloquent, central brain locations who were treated with SRS between January 2000 and April 2012. All patients had whole brain radiotherapy.

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Purpose: We conducted a retrospective population-based study to examine the survival outcomes in patients with brain metastases treated with salvage stereotactic radiosurgery (SRS), compared to boost SRS, after previous whole brain radiotherapy (WBRT).

Methods And Materials: From January 2000 to June 2011, 191 patients treated with WBRT and SRS for brain metastases in British Columbia were studied. Patients were divided into a boost cohort and a salvage cohort.

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Glioblastomas (GBM) are associated with high rates of relapse. These brain tumors are often resistant to chemotherapies like temozolomide (TMZ) and there are very few treatment options available to patients. We recently reported that polo-like kinase-1 (PLK1) is associated with the proliferative subtype of GBM; which has the worst prognosis.

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Purpose: To investigate predictive factors in the development of symptomatic radiation injury after treatment with linear accelerator-based stereotactic radiosurgery for intracerebral arteriovenous malformations and relate the findings to the conclusions drawn by Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC).

Methods And Materials: Archived plans for 73 patients who were treated at the British Columbia Cancer Agency were studied. Actuarial estimates of freedom from radiation injury were calculated using the Kaplan-Meier method.

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Glioblastoma multiforme (GBM) is an aggressive type of brain tumor where <3% of newly diagnosed cases in the patients will survive >5 years. In adults, GBM is the most common type of brain tumor. It is rarer in children, where it constitutes approximately 15% of all brain tumors diagnosed.

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Meningiomas are the most common intracranial primary neoplasm in adults. Over recent years, interest in this clinically diverse group of tumors has intensified, bringing new questions and challenges to the fore, particularly in the fields of epidemiology, radiology, pathology, genetics, and treatment. Interest in modern meningioma research has been stimulated by the high tumor prevalence and the advances in technology.

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Object: The goal in this study was to evaluate hearing preservation rates and to determine prognostic factors for this outcome following fractionated stereotactic radiotherapy (FSRT) of vestibular schwannoma.

Methods: Thirty-four consecutive patients with serviceable hearing who received FSRT between May 1998 and December 2003 were identified. Clinical and audiometry data were collected prospectively.

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This planning study evaluates the potential of intensity modulated treatment fields and inverse planning techniques in stereotactic radiosurgery to reduce healthy tissue dose. Twenty patients previously treated with stereotactic radiosurgery for arteriovenous malformation (AVM) were replanned with each of 4 techniques: circular non-coplanar arcs, dynamic arcs, static conformal fields, and intensity modulated radiosurgery (IMRS). Patients were selected having a maximum AVM dimension at least 20 mm, or volume greater than 10 cm(3).

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