T2 Detection of Tumor Invasion Within Segmented Components of Glioblastoma Multiforme

Purpose: To use T2-weighted images to detect tumor invasion when comparing normal individuals to groups of gliomablastoma multiforme (GBM) patients with varying levels of CXCR4, a chemokine receptor that promotes tumor migration. Materials and Methods: T2-weighted images were acquired preoperatively in 22 treatment-naive GBM patients. Two groups were formed based on the expression levels of CXCR4. A third group of normal volunteers was used for comparison. Each image was segmented to obtain four different clusters for tissue types identified as white matter, basal ganglia, gray matter/edema and cerebrospinal fluid (CSF)/tumor. Signal intensity histograms were formed for each cluster and compared between groups. Results: In every cluster the GBM groups displayed significantly higher standard deviations of intensity distributions when compared to normal subjects. Significant differences in skewness were found between normal subjects and GBM patients in the white matter. basal ganglia, and CSF/tumor. Further, when the two groups of GBM patients were compared the CXCR4-high group was found to have a significant shift in the median intensity values in the cluster containing gray matter and peritumoral edema. Conclusion: T2 signal intensity histograms in normal subjects differ significantly from those obtained from GBM groups, suggesting widespread dissemination of disease.