gms | German Medical Science

58. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

26. bis 29.04.2007, Leipzig

Reevaluation of functional PET data by awake glioma surgery

Evaluation funktioneller PET-Daten bei Wachoperationen in der Gliomchirurgie

Meeting Abstract

  • corresponding author M. Löhr - Klinik für Allgemeine Neurochirurgie der Universität zu Köln
  • S. Vollmar - Max-Planck-Institut für Neurologische Forschung, Medizinische Fakultät der Universität zu Köln
  • K. Herholz - Wolfson Molecular Imaging Centre, University of Manchester, UK
  • T. Reithmeier - Klinik für Allgemeine Neurochirurgie der Universität zu Köln
  • N. Klug - Klinik für Allgemeine Neurochirurgie der Universität zu Köln
  • J. A. Hampl - Klinik für Allgemeine Neurochirurgie der Universität zu Köln

Deutsche Gesellschaft für Neurochirurgie. 58. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC). Leipzig, 26.-29.04.2007. Düsseldorf: German Medical Science GMS Publishing House; 2007. DocSA.09.09

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

Published: April 11, 2007

© 2007 Löhr 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: Positron emission tomography (PET) has proven to accurately depict the metabolic properties of gliomas as well as the spatial localization of speech and motor function. However, there is still debate about the probable impairment of the functional PET data by adjoining or infiltrating tumor tissue. The aim of our prospective study was to compare the precision of the preoperative localization of eloquent areas as delineated by PET studies with the intraoperative electrophysiological and neuropsychological findings in an awake craniotomy setting.

Methods: In twelve patients with low grade, high grade or irradiated gliomas bordering or infiltrating eloquent areas for speech and/or motor perfomance, intraoperative neuronavigation (BrainLAB) was based on the coregistration of of [11C]methionine PET and thin-sliced MRI scans to outline the solid tumor and ist infiltration zone, and [15O]water PET for the localization of motor cortex and speech centers. All operations were performed under local anesthesia with continuous neuropsychologial monitoring, registration of the bispectral index, and the use of brain-mapping techniques.

Results: The simultaneous use of PET/MRI-guided neuronavigation, the application of electrophysiological techniques and neuropsychological monitoring allowed the safe resection of glial tumors even in highly eloquent areas. Electrophysiological mapping of the motor strip demonstrated an excellent anatomical correspondence between PET data and electrophysiological findings. However, if the precentral gyrus was infiltrated by tumor, epileptic fits or tranistory pareses occured after stimulation instead of the expected response. On the other hand, cortical stimulation of tumor infiltrated motor areas other than precentral gyrus (supplementary motor area and premotoric cortex) did not evoke seizures. Language-related areas infiltrated by glioma showed a heterogeneous response pattern upon cortical stimulation and simultaneous verb generation tasks, i.e. speech arrest as well as epileptic fits or no impact on verbal perfomance at all. In the latter cases, resection of this tissue had no impact on postoperative speech function either.

Conclusions: Whereas [15O]water PET data provide a precise delineation of the motor strip, the extent of language-related areas is overestimated. In awake craniotomies, the precise localization of eloquent regions by neuronavigation allows a more targeted electrophysiologic mapping, a “navigated mapping”, and thereby shortens duration of surgery.