[Value of Minimum Apparent Diffusion Coefficient in Peritumoral Edema in the Differential Diagnosis between Primary Central Nervous System Lymphoma and Glioblastoma]

Area of Science:

• Neuroradiology
• Oncology
• Diffusion Weighted Imaging

Background:

• Distinguishing primary central nervous system lymphoma (PCNSL) from glioblastoma (GBM) is crucial for appropriate treatment and patient outcomes.
• Magnetic resonance diffusion weighted imaging (DWI) provides valuable information about tissue microstructure.
• Peritumoral edema is a common feature in both PCNSL and GBM, necessitating methods for differential diagnosis.

Purpose of the Study:

• To evaluate the diagnostic role of minimum apparent diffusion coefficient (MinADC) values in peritumoral edema.
• To differentiate between primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM) using MinADC values from DWI.
• To assess the sensitivity and specificity of MinADC for distinguishing these two brain tumor types.

Main Methods:

• ADC values were measured in the peritumoral edema of 16 PCNSL and 31 GBM patients.
• Regions of interest were manually drawn on ADC maps to obtain MinADC values.
• Independent samples t-test and receiver operating characteristic (ROC) analysis were performed for statistical evaluation.

Main Results:

• MinADC values in PCNSL (mean 1.35±0.68 ×10^-3 mm²/s) were significantly higher than in GBM (mean 1.12±0.09 ×10^-3 mm²/s) (P=0.000).
• The area under the ROC curve was 0.986, indicating excellent diagnostic performance.
• A MinADC cutoff value of 1.245 ×10^-3 mm²/s achieved 94.1% sensitivity and 94.1% specificity for differentiating PCNSL from GBM.

Conclusions:

• MinADC values in peritumoral edema are a significant differentiator between PCNSL and GBM.
• This quantitative MRI metric offers a simple, effective, and non-invasive method for differential diagnosis.
• MinADC analysis can aid in guiding treatment strategies for patients with primary brain tumors.