title: Motor and language DTI Fiber Tracking combined with intraoperative subcortical mapping for surgical removal of gliomas.
abstract: Preoperative DTI Fiber Tracking (DTI-FT) reconstruction of functional tracts combined with intraoperative subcortical mapping (ISM) is potentially useful to improve surgical procedures in gliomas located in eloquent areas. Aims of the study are: (1) to evaluate the modifications of fiber trajectory induced by the tumor; (2) to validate preoperative DTI-FT results with intraoperative identification of functional subcortical sites through direct subcortical stimulation; (3) to evaluate the impact of preoperative DTI-FT reconstructions in a neuronavigational setup combined with ISM technique on duration and modalities of surgical procedures, and on functional outcome of the patients. Data are available on 64 patients (52 low-grade and 12 high-grade gliomas). DTI-FT was acquired by a 3-T MR scanner with a single-shot EPI sequence (TR/TE 8986/80 ms, b=1000 s/mm) with gradients applied along 32 non-collinear directions. 3D Fast Field Echo (FFE) T1-weighted imaging (TR/TE 8/4 ms) was performed for anatomic guidance. The corticospinal tract (CST), superior longitudinal, inferior fronto-occipital and uncinatus fasciculi were reconstructed. Data were transferred to the neuronavigational system. Functional subcortical sites identified during ISM were correlated with fiber tracts depicted by DTI-FT. In high-grade gliomas, DTI-FT depicted tracts mostly at the tumor periphery; in low-grade gliomas, fibers were frequently located inside the tumor mass. There was a high correlation between DTI-FT and ISM (sensitivity for CST=95%, language tracts=97%). For a proper reconstruction of the tracts, it was necessary to use a low FA threshold of fiber tracking algorithm and to position additional regions of interest (ROIs). The combination of DTI-FT and ISM decreased the duration of surgery, patient fatigue, and intraoperative seizures. Combination of DTI-FT and ISM allows accurate identification of eloquent fiber tracts and enhances surgical performance and safety maintaining a high rate of functional preservation.
authors.affiliation: Neurosurgery, Department of Neurological Sciences, University of Milano, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via Francesco Sforza 35, 20122, Milan, Italy. lorenzo.bello@unimi.it
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bello
authors.forename: Anna
authors.initials: A
authors.lastname: Gambini
authors.forename: Antonella
authors.initials: A
authors.lastname: Castellano
authors.forename: Giorgio
authors.initials: G
authors.lastname: Carrabba
authors.forename: Francesco
authors.initials: F
authors.lastname: Acerbi
authors.forename: Enrica
authors.initials: E
authors.lastname: Fava
authors.forename: Carlo
authors.initials: C
authors.lastname: Giussani
authors.forename: Marcello
authors.initials: M
authors.lastname: Cadioli
authors.forename: Valeria
authors.initials: V
authors.lastname: Blasi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Casarotti
authors.forename: Costanza
authors.initials: C
authors.lastname: Papagno
authors.forename: Arun K
authors.initials: AK
authors.lastname: Gupta
authors.forename: Sergio
authors.initials: S
authors.lastname: Gaini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Scotti
authors.forename: Andrea
authors.initials: A
authors.lastname: Falini
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D001932:Brain Neoplasms / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D019054:Evoked Potentials, Motor; D005260:Female; D005910:Glioma / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D007802:Language; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome