Risk Assessment by Pre-surgical Tractography in Left Hemisphere Low-Grade Gliomas

Abstract

Background: Tracking the white matter principal tracts is routinely typically included during the pre-surgery planning examinations and has revealed to limit functional resection of low-grade gliomas (LGGs) in eloquent areas.Objective: We examined the integrity of the Superior Longitudinal Fasciculus (SLF) and Inferior Fronto-Occipital Fasciculus (IFOF), both known to be part of the language-related network in patients with LGGs involving the temporo-insular cortex. In a comparative approach, we contrasted the main quantitative fiber tracking values in the tumoral (T) and healthy (H) hemispheres to test whether or not this ratio could discriminate amongst patients with different post-operative outcomes.Methods: Twenty-six patients with LGGs were included. We obtained quantitative fiber tracking values in the tumoral and healthy hemispheres and calculated the ratio (HIFOF–TIFOF)/HIFOF and the ratio (HSLF–TSLF)/HSLF on the number of streamlines. We analyzed how these values varied between patients with and without post-operative neurological outcomes and between patients with different post-operative Engel classes.Results: The ratio for both IFOF and SLF significantly differed between patient with and without post-operative neurological language deficits. No associations were found between white matter structural changes and post-operative seizure outcomes.Conclusions: Calculating the ratio on the number of streamlines and fractional anisotropy between the tumoral and the healthy hemispheres resulted to be a useful approach, which can prove to be useful during the pre-operative planning examination, as it gives a glimpse on the potential clinical outcomes in patients with LGGs involving the left temporo-insular cortex.

Inferior fronto‐occipital fascicle displacement in temporoinsular gliomas using diffusion tensor imaging

“…Knowledge of the structural involvement and exact course of the tracts in oncological patients would provide useful information to guide tumor resection and minimize surgical morbidity. [4][5][6]12,24 F I G U R E 3 Patterns of tract displacement depending on main location of the tumor in the temporal lobe. Above (A-C) examples of medial location (A), lateral-medial location lesion (B), and lateral location lesions (C); 2-dimensional bilateral inferior frontal occipital fascicle trajectory on this slice is marked in orange.…”

“…As far as we are aware, this is the first study that aims to describe and predict the pattern of involvement and displacement of the IFOF by preoperative DTI. Knowledge of the structural involvement and exact course of the tracts in oncological patients would provide useful information to guide tumor resection and minimize surgical morbidity 4–6,12,24 …”

“…Precise mapping of brain structures is currently done by combining direct-electrical stimulation and neuromonitorization techniques during awake and asleep interventions with the guidance of presurgical MRI mapping techniques such as functional MRI and diffusion tensor imaging (DTI) tractography, which can be integrated into the operating room. [5][6][7] The anatomical components of this fasciculus have been studied extensively by ex vivo, surgical dissection, and in vivo neuroimaging MRI techniques such as DTI-tractography. [8][9][10][11] However, in the context of tumor surgery, little has been said about the precise patterns of involvement of the IFOF.…”

“…To avoid surgical damage and consequent postsurgical neurological deficits, functional brain mapping techniques aim to offer the maximum possible safe resection, optimizing patient survival while avoiding damage to essential eloquent cortical and subcortical structures, such as the IFOF. Precise mapping of brain structures is currently done by combining direct‐electrical stimulation and neuromonitorization techniques during awake and asleep interventions with the guidance of presurgical MRI mapping techniques such as functional MRI and diffusion tensor imaging (DTI) tractography, which can be integrated into the operating room 5–7 …”

Advances in Multidisciplinary Management of Skull Base Meningiomas

“…Diffusion MRI and tractography currently represent the only way to reconstruct white matter in humans in vivo, providing a non-invasive and feasible method for evaluating the subcortical pathways changes, especially in glioma surgery [ 21 , 22 , 23 ]. In recent years, its use has been gradually spread for preoperative cranial nerve reconstruction in SBM surgery [ 24 , 25 , 26 ].…”