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

Tamara Ius,Francesca Palese,Miran Skrap,Teresa Somma,Annacarmen Nilo,Cinzia Baiano,Barbara Tomasino,Marta Maieron,Ilaria Guarracino,Giada Pauletto

doi:10.3389/fneur.2021.648432

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.

Highlights

Low-grade gliomas (LGGs) present a surgical challenge because of the poorly defined tumoral borders and the infiltration of white matter tracts [1, 2]
Despite the inherent limitations associated with imaging reconstruction algorithms, diffusion tensor imaging (DTI) (Diffusion Tensor Imaging) has recently been included in the presurgical glioma workup to aid in the mapping of functional pathways and to prevent extensive damage associated with radical resection [3, 6]
Insular lobe was involved in 17 cases, while temporal lobe in 9 cases

Summary

Introduction

Low-grade gliomas (LGGs) present a surgical challenge because of the poorly defined tumoral borders and the infiltration of white matter tracts [1, 2]. It is of utmost importance to develop a reliable non-invasive pre-operative method to estimate the risk of post-operative deficits in the clinical management of these patients. DTI currently represents the only way to investigate white matter in humans in vivo [7], providing a non-invasive and feasible method for evaluating changes in the main language pathways, its preoperative predictive role to estimate the risk of post-operative deficits is poorly investigated. 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

Methods

Results

Discussion

Conclusion