Constrained Spherical Deconvolution White Matter Tractography in Neuro-Oncology and Deep Brain Stimulation: An Illustrative Case Series

Highlights What are the main findings? Constrained spherical deconvolution (CSD) tractography outperformed diffusion tensor imaging in visualizing eloquent white matter pathways in complex neurosurgical settings. CSD-based reconstructions reliably matched intraoperative stimulation findings and postoperative functional outcomes in neuro-oncology and DBS cases. What are the implications of the main findings? CSD tractography may improve surgical safety by refining functional boundaries during tumor resection in eloquent brain regions. Personalized CSD-guided planning can optimize DBS targeting and stimulation programming, supporting its integration into routine neurosurgical workflows. Abstract Background/Objectives: Preservation of critical white matter (WM) pathways is essential for maximizing surgical safety in neuro-oncology and functional neurosurgery. Constrained spherical deconvolution (CSD) offers superior modeling of complex fiber architecture compared to diffusion tensor imaging (DTI). This case series evaluates the clinical utility of CSD in surgical planning and intraoperative navigation. Methods: A retrospective review of 20 patients (15 brain tumors, 5 functional disorders) treated between September 2022, and September 2024 was performed. All patients underwent preoperative MRI with CSD-based reconstruction of eloquent WM tracts. Clinical presentation, tract involvement, surgical strategy, and postoperative outcomes were analyzed. Results: CSD reliably reconstructed CST, AF, IFOF, OT, and DRTT depending on tumor location or DBS target. Compared with standard DTI, CSD provided improved delineation of tract extent and tumor–tract interfaces. Gross total resection (GTR) was achieved in all tumor patients without new neurological deficits. DBS cases showed precise correlation between stimulation thresholds, side effects, and CSD-predicted distances to critical WM tracts. DRTT targeting resulted in marked clinical improvement in Holmes tremor. Conclusions: CSD enhances anatomical accuracy in WM tract visualization, supporting safer resections in eloquent areas and improving DBS targeting. Its integration into routine workflow may optimize neurosurgical outcomes.