Tumor-Associated Tractography Derived from High-Angular-Resolution Q-Space MRI May Predict Patterns of Cellular...

Area of Science:

• Neuroimaging
• Oncology
• Radiomics

Background:

• Glioblastoma invasion beyond visible margins contributes to recurrence and poor survival.
• Current neuroimaging lacks radiomic biomarkers for tumor infiltration direction and extent.
• Understanding glioblastoma invasion pathways is crucial for improving patient outcomes.

Purpose of the Study:

• To investigate the utility of Q-space imaging (QSI) and tractography for characterizing glioblastoma invasion.
• To identify radiomic biomarkers from QSI-derived tractography associated with glioblastoma patient survival.
• To compare in vivo human glioblastoma tractography with ex vivo models.

Main Methods:

• Preoperative Q-space magnetic resonance imaging (QSI) was performed on newly diagnosed glioblastoma patients (n=7) and a historical cohort (n=66).
• Tumor-associated tractography was generated by analyzing inter-voxel coherence patterns intersecting tumor segmentations.
• Associations between tractography metrics and survival were assessed; RNA sequencing and PDX mouse models were utilized for validation.

Main Results:

• QSI-derived tractography revealed tumor-intersecting pathways extending into brain parenchyma in all glioblastoma cases, consistent across human cohorts and PDX mouse models.
• Intra-tumoral mean diffusivity, mean tract length, and mean projecting tract length were significant predictors of overall survival (p < 0.05).
• RNA sequencing of tract-associated tissue showed overexpression of cell motility-regulating transcripts.

Conclusions:

• QSI effectively discriminates tumor-specific coherence patterns representing white matter pathways susceptible to glioblastoma invasion.
• Tractography-derived radiomic biomarkers show prognostic value for glioblastoma.
• These findings support QSI-tractography for future therapeutic targeting, patient stratification, and prognosis in glioblastoma.