gms | German Medical Science

59th Annual Meeting of the German Society of Neurosurgery (DGNC)
3rd Joint Meeting with the Italian Neurosurgical Society (SINch)

German Society of Neurosurgery (DGNC)

1 - 4 June 2008, Würzburg

Detection of tumor invasion into the pyramidal tract in glioma patients suffering from sensorimotor deficites by correlation of FET-PET and Diffusion Tensor Imaging

Nachweis der Ausdehnung von Tumorzellinfiltration in die Pyramidenbahn bei Gliompatienten mit sensomotorischen Defiziten durch Korrelation von FET-PET und Diffusions-Tensor-Bildgebung

Meeting Abstract

  • corresponding author E. Pölking - Department of Neurosurgery, Friedrich-Alexander-University, Erlangen-Nuremberg
  • O. Ganslandt - Department of Neurosurgery, Friedrich-Alexander-University, Erlangen-Nuremberg
  • C. Nimsky - Department of Neurosurgery, Friedrich-Alexander-University, Erlangen-Nuremberg
  • M. Buchfelder - Department of Neurosurgery, Friedrich-Alexander-University, Erlangen-Nuremberg
  • T. Kuwert - Department of Nuclear Medicine, Friedrich-Alexander-University, Erlangen-Nuremberg
  • A. Stadlbauer - Department of Neurosurgery, Friedrich-Alexander-University, Erlangen-Nuremberg

Deutsche Gesellschaft für Neurochirurgie. Società Italiana di Neurochirurgia. 59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch). Würzburg, 01.-04.06.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocP 091

The electronic version of this article is the complete one and can be found online at:

Published: May 30, 2008

© 2008 Pölking et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: It is generally accepted that standard MR imaging does not depict the true extent of tumor cell invasion in gliomas. Thus, the challenge in treatment planning is to define tumor borders. We investigated the feasibility of advanced imaging methods, i.e. diffusion tensor imaging (DTI), fiber tracking and 18F-Fluoroethyl-Tyrosine (FET) PET, in the detection of tumor invasion into white matter structures, which are not visible in routine MRI.

Methods: Quantitative fiber tracking was performed in 10 patients suffering from gliomas WHO grades II-IV. 5 patients experienced preoperative sensorimotor deficits. The ratio of fractional anisotropy (FA) between the ipsilateral and contralateral pyramidal tract was calculated. Stereotactic biopsies were obtained from 5 patients and histopathologically evaluated by determination of the absolute numbers and percentages of tumor cells. FET PET scans were performed and the tumor-to-brain-ratio (TBR) of FET-uptake was calculated for both, pyramidal tracts and biopsy sites.

Results: The FA-ratio within the ipsilateral pyramidal tract was lower in patients with sensorimotor deficits (0.61–1.06) compared to patients without deficits (0.92–1.06). In patients with preoperative sensorimotor deficits we found a significantly (p=0.028) higher TBR of FET uptake (1.01–1.59) than in patients without any deficits (0.96–1.08). The TBR of FET-uptake showed a strong correlation (r=0.696; p=0.001) with the absolute number of tumor cells and a moderate correlation (r=0.535; p=0.005) with the percentage of tumor cells.

Conclusions: Our data show an association between preoperative sensorimotor deficits, increased FET uptake and decreased FA-ratio in the pyramidal tract. We demonstrated a correlation between tumor invasion and FET uptake. These findings may help to distinguish between edema versus tumor-associated neurological deficits and could prevent the destruction of important structures like the pyramidal tract during tumor operations by a more precise preoperative planning.