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

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

doi:10.3389/fneur.2021.648432

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

Front Neurol. 2021 Feb 15:12:648432. doi: 10.3389/fneur.2021.648432. eCollection 2021.

Authors

Affiliations

¹ Neurosurgery Unit, Department of Neurosciences, Santa Maria della Misericordia University Hospital, Udine, Italy.
² Division of Neurosurgery, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Università degli Studi di Napoli Federico II, Naples, Italy.
³ Scientific Institute, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) E. Medea, Pordenone, Italy.
⁴ Neurology Unit, Department of Neurosciences, Santa Maria della Misericordia University Hospital, Udine, Italy.
⁵ Clinical Neurology Unit, Department of Neurosciences, Santa Maria della Misericordia University Hospital, Udine, Italy.
⁶ Medical Physics, Santa Maria della Misericordia University Hospital, Udine, Italy.
⁷ Medical Area Department, University hospital, Udine, Italy.

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 (H_IFOF-T_IFOF)/H_IFOF and the ratio (H_SLF-T_SLF)/H_SLF 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.

Keywords: arcuate fasciculus; diffusion tensor imaging analysis; inferior fronto-occipital fasciculus; intraoperative electric stimulation; low-grade gliomas.