Tractography for Subcortical Resection of Gliomas Is Highly Accurate for Motor and Language Function: ioMRI-Based Elastic Fusion Disproves the Severity of Brain Shift

Sebastian Ille,Maximilian Schwendner,Bernhard Meyer,Sandro M Krieg,Axel Schroeder,Wei Zhang

doi:10.3390/cancers13081787

Sebastian Ille, Maximilian Schwendner + Show 4 more

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https://doi.org/10.3390/cancers13081787

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Journal: Cancers	Publication Date: Apr 9, 2021
Citations: 12	License type: CC BY 4.0

Affiliation: Rechts der Isar Hospital, Technical University of Munich

Abstract

Simple SummaryTractography enables the visualization of eloquent white matter pathways. Inaccuracies due to brain shift might occur intraoperatively. The aim of this study was to evaluate the impact of intraoperative magnetic resonance imaging (MRI)-based elastic fusion on preoperative tractography for subcortical resection of gliomas. We confirmed the high accuracy of tractography during the whole course of surgery.When using preoperative tractography intraoperatively, inaccuracies due to brain shift might occur. Intraoperative tractography is rarely performed. Elastic fusion (EF) is a tool developed to compensate for brain shift, gravity, and tissue resection based on intraoperative images. Our hypothesis was that preoperative tractography is accurate and adjustments of tractography by intraoperative magnetic resonance imaging (ioMRI)-based EF (IBEF) compensate for brain shift. Between February 2018 and June 2019, 78 patients underwent eloquent (46 motor, 32 language) glioma resection in our department using intraoperative MRI. Mean distances between the resection cavity and tractography were analyzed and correlated with clinical outcomes. The mean ± standard deviation (range) distance after the application of IBEF was 5.0 ± 2.9 mm (0–10 mm) in patients without surgery-related motor deficits compared with 1.1 ± 1.6 mm (0–5 mm) in patients who showed new permanent surgery-related motor deficits postoperatively (p < 0.001). For language, the distance was 0.7 ± 1.2 mm (0–2 mm) in patients with new permanent deficits compared with 3.1 ± 4.5 mm (0–14 mm) in patients without new permanent surgery-related language deficits (p = 0.541). Preoperative tractography corrected by IBEF for subcortical resection of gliomas is highly accurate. However, at least for such subcortical anatomy, the severity of brain shift was considerably overestimated in the past.

Highlights

IntroductionFor the resection of eloquent brain tumors, a maximum extent of resection (EOR)
The aim of this study was to evaluate whether the fusion of preoperative tractography and intraoperative anatomical MRI scans provides accurate data correlating with the patients’ postoperative clinical outcomes, and how tractography corrected by ioMRI-based elastic fusion (IBEF) can compensate for intraoperative brain shift to provide improved risk assessment regarding further resection after intraoperative magnetic resonance imaging (ioMRI)
Descriptive statistics were calculated for patient- and tumor-related cases without surgery-related deficitsbetween were compared with patients with surgery-related characteristics as well as for distances fiber tracts and the resection cavity

Summary

Introduction

For the resection of eloquent brain tumors, a maximum extent of resection (EOR). Tractography enables the visualization of eloquent subcortical pathways prior to surgery, helping to identify subcortical structures, such as the corticospinal tract (CST) or arcuate fascicle, in relation to the tumor. Compared with the gold standard of intraoperative direct subcortical stimulation, tractography shows good concordance [6,7,8,9,10]. During surgery, opening of the dura, loss of corticospinal fluid, and tumor resection cause an increasing brain shift. This might pose the risk of increasing the inaccuracy of tractography, especially at the end of tumor resection, where tractography might be of most importance

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