The Anisotropic Component of the Diffusion Tensor (DTI-Q) Is Correlated to Overall Survival in Glioblastoma (GBM)

Abstract

Abstract AIMS The aim of this study was to test if a correlation exists between the median voxel DTI-Q and overall survival in patients with GBM. METHOD The median voxel anisotropic (DTI-Q) values, calculated for the whole brain, the contrast-enhancing hemisphere and the contralateral hemisphere, were calculated using FSL (FMRIB Software Library, Oxford) for 33 patients with a primary diagnosis of GBM. Overall survival was calculated by subtracting the date of initial resection surgery from the date of death, for each included patient. Using R statistical software, the Pearson’s correlation coefficient was computed to establish the significance of the relationship between overall survival and whole brain median DTI-Q values, contrast-enhancing hemisphere median DTI-Q values and non-contrast-enhancing hemisphere median DTI-Q values. RESULTS There is a significant correlation between the median voxel DTI-Q of the whole brain and overall survival (t = -2.5362, df = 31, p-value = 0.01646), median voxel DTI-Q of the contrast-enhancing hemisphere and overall survival (t = -2.1235, df = 31, p-value = 0.0418) and the median voxel DTI-Q of the contralateral (non-contrast-enhancing) hemisphere and overall survival (t = -2.5212, df = 31, p-value = 0.01705). CONCLUSION The median anisotropic component of the diffusion tensor, calculated for the whole brain, contrast-enhancing and non-contrast-enhancing hemisphere, is significantly related to overall survival. This demonstrates the potential utility of DTI metrics as prognostic biomarkers that can readily be calculated in routine practice.