Functional preoperative and intraoperative mapping and monitoring: increasing safety and efficacy in glioma surgery

Abstract

<jats:p>Greater extent of resection (EOR) of low-grade gliomas is associated with improved survival. Proximity to eloquent cortical regions often limits resectability and elevates the risk of surgery-related deficits. Therefore, functional localization of eloquent cortex or subcortical fiber tracts can enhance the EOR and functional outcome. Imaging techniques such as functional MRI and diffusion tensor imaging fiber tracking, and neurophysiological methods like navigated transcranial magnetic stimulation and magnetoencephalography, make it possible to identify eloquent areas prior to resective surgery and to tailor indication and surgical approach but also to assess the surgical risk. Intraoperative monitoring with direct cortical stimulation and subcortical stimulation enables surgeons to preserve essential functional tissue during surgery. Through tailored pre- and intraoperative mapping and monitoring the EOR can be maximized, with reduced rates of surgery-related deficits.</jats:p>

Factors triggering an additional resection and determining residual tumor volume on intraoperative MRI: analysis from a prospective single-center registry of supratentorial gliomas

“…Awake craniotomy and/or electrophysiology assessments with stimulation and mapping can be applied in combination to iMRI to safely delineate nonfunctional areas for resection in eloquent tumors. 13,14 We observed an independent association with higher residual tumor volume on iMRI in eloquent tumors (OR 1.7, p = 0.010) ( Table 5). This probably reflects a more defensive resection when approaching eloquent areas, until iMRI provides reassurance of tumor boundaries.…”

“…4,13 Particularly in iMRI-guided surgery, the ability to delineate residual tumor and continue with the resection is a feature that might help to safely overcome limitations of conventional surgical techniques. The above-mentioned risk factors for unintended incomplete resections might not apply to iMRI cases and should be refined in this regard.…”

Intraoperative Monitoring with Cortical Estimulation

“…The correct surgical planning for radical resection of gliomas allows a better quality of life and increases patient survival 13,[24][25][26][27][28] . However, there is a potentially high risk of permanent sequelae, particularly when the tumor is located within eloquent brain regions.…”

Diffusion tensor imaging tractography and intraoperative neurophysiological monitoring in surgery of intracranial tumors located near the pyramidal tract

“…1, в хирургии внутри-мозговых опухолей головного мозга сочетанное ис-пользование предоперационных (ДТ-трактография) и интраоперационных методов нейрофизиологиче-ского контроля имеет аддитивный эффект [18].…”