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

Integration of metabolic imaging and molecular genetic profiling of serial stereotactic biopsies are valuable for histological discrimination of oligodendrogliomas, oligoastrocytomas and astrocytomas WHO° II/III

Integration der metabolischen Bildgebung und molekulargenetischen Untersuchung an seriellen stereotaktischen Biopsien unterstützt die histologische Unterscheidung von Oligodendrogliomen, Oligoastrozytomen und Astrozytomen WHO° II/III

Meeting Abstract

  • corresponding author N. Thon - Department of Neurosurgery, University Hospital Großhadern, Munich
  • C. Erös - Department of Neurosurgery, University Hospital Großhadern, Munich
  • G. Pöpperl - Department of Nuclear Medicine, University Hospital Großhadern, Munich
  • J. Herms - Center for Neuropathology and Prion Reseach, Ludwig-Maximilians-University, Munich
  • J.-C. Tonn - Department of Neurosurgery, University Hospital Großhadern, Munich
  • F. W. Kreth - Department of Neurosurgery, University Hospital Großhadern, Munich

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. DocMO.13.07

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dgnc2008/08dgnc130.shtml

Published: May 30, 2008

© 2008 Thon et al.
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Outline

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Objective: Modern treatment strategies of gliomas have to consider recent advances in metabolic imaging and molecular markers with respect to individualized multimodal therapeutic regimes. Aim of this study was to correlate 18F-FET-PET based tumor grading, LOH1p/19q and MGMT promoter methylation with histological classification of gliomas WHO° II and III from serial stereotactic biopsies in patients with eloquently located tumors.

Methods: 86 patients have been included in this prospective, single-center study. Dynamic 18F-FET PET studies have been matched with MRI scans prior to stereotactic surgery to mark regions of interest. Oligodendroglial tumor characterization by 18F-FET PET was performed using max. standard uptake value (mSUV) combined with kinetic uptake analysis. Biopsies have been classified according WHO criteria. LOH1p/19q and MGMT methylation status has been detected using small tissue samples adjusted fluorescence in situ hybridization and methylation-specific PCR methods.

Results: 8 oligodendroglioma (O), 24 mixed oligoastrocytoma (OA) and 54 astrocytoma (A) (WHO° II and III) have been included. 1p/19q codeletion (33/78 (42.3%)) was significantly more frequent in tumors containing an oligodendroglial component (25/31 O+OA (80.7%) versus 8/47 A (17.0%); p<0,05). 55/75 gliomas (73,3%) exhibited methylation at the MGMT gene (26/28 O+OA (92,9%) versus 29/46 A (63%); p<0,05). Oligodendroglial tumors showed significantly elevated LOH 1p/19q and MGMT methylation co-expression status compared to astroglial tumors (24/28 O+OA (85.7%) versus 6/45 A (13.3%); p<0,05). Oligodendroglial tumors have been reliably identified by analysing 18F-FET-PET mSUV and uptake kinetics (22/26 O+OA (84.6%)). 43 out of 79 patients underwent multimodal treatments prior to stereotactic procedure. In case of LOH 1p/19q and MGMT methylation co-expression status 11/11 newly diagnosed patients with oligodendroglial tumors have been initially treated with chemotherapy. 2/2 Oligoastrocytomas without LOH/MGMT methylation underwent primary radiotherapy.

Conclusions: Combination of metabolic 18F-FET-PET analysis and molecular genetic marker profiling with histopathological classification of serial stereotactic biopsies was sufficient to gather more information upon the difficult discrimination of oligodendroglial tumors and mixed oligoastrocytoma from astrogliomas. Since MGMT and LOH are correlated with favourable prognosis in certain glioma entities this diagnostic strategy can evaluate the role of molecular markers in a more general concept of glioma therapy.