Microstructure mapping with time-dependent diffusion MRI differentiates primary central nervous system lymphoma from...

Area of Science:

• Neuroimaging
• Oncology
• Radiology

Background:

• Accurate preoperative differentiation between glioblastoma (GBM) and primary central nervous system lymphoma (PCNSL) is essential for effective treatment planning.
• Distinguishing between these two malignant brain tumors using conventional methods can be challenging.

Purpose of the Study:

• To assess the diagnostic value of time-dependent diffusion MRI (td-dMRI)-derived microstructural parameters in differentiating PCNSL from GBM.
• To correlate these MRI-derived parameters with histopathological findings.

Main Methods:

• 32 GBM and 19 PCNSL patients underwent 3.0-T MRI using oscillating gradient spin-echo (OGSE) and pulsed gradient spin-echo (PGSE) sequences.
• Microstructural parameters including intracellular volume fraction (Vin), cell diameter, cellularity, and extracellular diffusivity (Dex) were quantified.
• Diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis, and histopathological correlation was performed.

Main Results:

• PCNSL showed significantly smaller cell diameter, lower Dex, and higher Vin and cellularity compared to GBM in enhancing tumor regions (p < 0.001).
• Vin demonstrated the highest diagnostic accuracy (AUC=0.901), outperforming other parameters.
• Vin correlated strongly with the histopathological nuclei fraction (r=0.76, p < 0.001).

Conclusions:

• Intracellular volume fraction (Vin) derived from td-dMRI is a highly accurate and promising biomarker for the preoperative differential diagnosis between GBM and PCNSL.
• Further development of combined diagnostic models did not yield statistically robust results in this cohort.