Intraoperative Augmented Reality Fiber Tractography for Primary Motor Area Glioma Resection

The implementation of intraoperative augmented reality fiber tractography (iAR-FT) into the surgical workflow for high-grade supratentorial gliomas has been shown to be effective and safe in maximizing the extent of resection and progression-free survival through the surgeon's enhanced 3-dimensional awareness of the spatial localization of fiber tracts.^1-3 Primary motor area tumors present special challenges due to the high eloquence of the precentral gyrus and risk of postoperative onset or worsening of motor deficits, as well as limited postoperative plasticity.⁴ Although essential, electrical stimulation mapping (ESM) techniques have a number of limitations with respect to primary motor pathways, including a higher risk of intraoperative stimulation-evoked seizures, a risk of false negatives in the presence of preoperative deficits, a nonnegligible risk of permanent deterioration even in the presence of negative stimulation maps, and, most importantly, limited spatial resolution.^4-8 The rationale for integrating ESM and iAR-FT is to compensate for the limitations of the former in terms of morphologic and spatial representation of fiber tracts. The benefits of coupling iAR-FT with ESM techniques allow for continuous integrated anatomical-functional feedback during surgery. In Video 1 we describe the key technical aspects and benefits of iAR-FT-assisted surgery for maximal safe gross total resection of a primary motor area grade IV astrocytoma.