Differentiation of edema and glioma infiltration: proposal of a DTI-based probability map

Friso W. A. Hoefnagels, Philip De Witt Hamer, Ernesto Sanz-Arigita, Sander Idema, Joost P. A. Kuijer, Petra J. W. Pouwels, Frederik Barkhof, W. Peter Vandertop
J Neurooncol. 2014-07-31; 120(1): 187-198
DOI: 10.1007/s11060-014-1544-9


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1. J Neurooncol. 2014 Oct;120(1):187-98. doi: 10.1007/s11060-014-1544-9. Epub 2014
Jul 31.

Differentiation of edema and glioma infiltration: proposal of a DTI-based
probability map.

Hoefnagels FW(1), De Witt Hamer P, Sanz-Arigita E, Idema S, Kuijer JP, Pouwels
PJ, Barkhof F, Vandertop WP.

Author information:
(1)Department Neurosurgery, Neurosurgical Center Amsterdam, VU University Medical
Center, P.O. Box 7057, 1007, MB, Amsterdam, The Netherlands,
.

Conflicting results on differentiating edema and glioma by diffusion tensor
imaging (DTI) are possibly attributable to dissimilar spatial distribution of the
lesions. Combining DTI-parameters and enhanced registration might improve
prediction. Regions of edema surrounding 22 metastases were compared to
tumor-infiltrated regions from WHO grade 2 (12), 3 (10) and 4 (18) gliomas. DTI
data was co-registered using Tract Based Spatial Statistics (TBSS), to measure
Fractional Anisotropy (FA) and Mean Diffusivity (MD) for white matter only, and
relative changes compared to matching reference regions (dFA and dMD). A
two-factor principal component analysis (PCA) on metastasis and grade 2 glioma
was performed to explore a possible differentiating combined factor. Edema
demonstrated equal MD and higher FA compared to grade 2 and 3 glioma (P < 0.001), but did not differ from glioblastoma. Differences were non-significant when corrected for spatial distribution, since reference regions differed strongly (P < 0.001). The second component of the PCA (PCA-C2) did differentiate edema and low-grade tumor (sensitivity 91.7%, specificity 86.4%). PCA-C2 scores were plotted voxel-wise as a probability-map, discerning distinct areas of presumed edema or tumor infiltration. Correction of spatial dependency appears essential when differentiating glioma from edema. A tumor-infiltration probability-map is presented, based on supplementary information of multiple DTI parameters and spatial normalization. DOI: 10.1007/s11060-014-1544-9 PMID: 25079117 [Indexed for MEDLINE]

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