gms | German Medical Science

57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

11. bis 14.05.2006, Essen

Fiber tractography in patients with gliomas: Histopathologic evaluation of tumor infiltration of white matter tracts

Tractographie bei Gliompatienten: Histologische Untersuchung zur Tumorinfiltration der Faserbahnen

Meeting Abstract

  • corresponding author O. Ganslandt - Neurochirurgische Klinik, Universität Erlangen-Nürnberg
  • A. Stadlbauer - Neurochirurgische Klinik, Universität Erlangen-Nürnberg
  • R. Buslei - Institut für Neuropathologie, Universität Erlangen
  • M. Buchfelder - Neurochirurgische Klinik, Universität Erlangen-Nürnberg
  • R. Fahlbusch - Neurochirurgische Klinik, Universität Erlangen-Nürnberg
  • C. Nimsky - Neurochirurgische Klinik, Universität Erlangen-Nürnberg

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. Essen, 11.-14.05.2006. Düsseldorf, Köln: German Medical Science; 2006. DocSA.03.05

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dgnc2006/06dgnc099.shtml

Veröffentlicht: 8. Mai 2006

© 2006 Ganslandt et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

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Objective: To correlate the changes in fractional anisotropy (FA) and in mean diffusivity (MD) using diffusion tensor MR imaging (DTI) with the degree of tumor cell infiltration in gliomas. To assess the extent of tumor cell infiltration in brain fiber tracks.

Methods: Twenty patients (8f/12m; 53-17y) with gliomas (7 WHO II, 13 WHO III) underwent DTI with a 1.5 T system (Siemens Sonata). DTI data were obtained using an EPI diffusion sequence (TR/TE 9200/86ms) with 6 diffusion directions (b=1000), an isotropic voxel size of 1.9 mm and 5 averages. FA and MD (=mean ADC) values were calculated from DTI data. Co-registration with a 3D MPRAGE, which was used for stereotactic brain biopsies, allowed correlation of FA and MD values with histopathologic findings expressed as % tumor infiltration (%TI). Fiber Tractography using DTI-Studio was performed to investigate the integrity of white matter tracts in the border zone of the lesions. Anatomically segmented ROIs for seed areas were placed for tracking of callosal, projection and/or association fibers, depending on the location of the lesion. The tracing procedures were stopped for FA<0.1 or tract turning-angle>60°.

Results: The histopathologic findings of 75 MR image-guided stereotactic biopsies from all 20 patients were correlated with the corresponding FA and MD values at the biopsy locus. For MD we found a positive linear correlation (r=0.412, p=0.0005), whereas FA showed a more distinct negative linear correlation (r=-0.821, p<0.0001) with %TI. A linear regression model resulted in an intersection at 0%TI for FA=0.28. Tractography showed FA ranging from 0.39-0.20 (0.25±0.05) of the brain fiber tracts located nearest to the lesions. Based on the regression model, these values are equal to 20%TI (range 0-50%TI) of intact brain fiber tracts in the border zone of gliomas. In 6 patients we retrospectively reconstructed intact brain fiber tracts at the biopsy loci (2-32%TI).

Conclusions: FA is more significant than MD (mean ADC) for the assessment and delineation of pathologic changes in brain tumors. We showed potential tumor cell infiltration of intact brain fiber tracts. For gliomas WHO II and III, a FA<0.2 allow the assumption of a %TI>50% and a very low probability of intact brain fiber tracts.