gms | German Medical Science

62nd Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Polish Society of Neurosurgeons (PNCH)

German Society of Neurosurgery (DGNC)

7 - 11 May 2011, Hamburg

Prognostic value of 18F-FET PET, MRI and cytoreduction in 61 low-grade glioma

Meeting Abstract

  • M. Rapp - Neurochirurgische Klinik, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Deutschland
  • T. Beez - Neurochirurgische Klinik, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Deutschland
  • K.J. Langen - Institut für Neurowissenschaften und Medizin 4, Forschungszentrum Jülich, Jülich, Deutschland
  • H.J. Steiger - Neurochirurgische Klinik, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Deutschland
  • M. Sabel - Neurochirurgische Klinik, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Deutschland

Deutsche Gesellschaft für Neurochirurgie. Polnische Gesellschaft für Neurochirurgen. 62. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgen (PNCH). Hamburg, 07.-11.05.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. DocMO.04.09

DOI: 10.3205/11dgnc017, URN: urn:nbn:de:0183-11dgnc0178

Published: April 28, 2011

© 2011 Rapp et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

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Objective: This long-term study investigates prognostic factors in patients with untreated, non-enhancing, supratentorial low-grade glioma.

Methods: In a prospective study starting in 1999, baseline O-(2-[18F] fluoroethyl)-L-tyrosine (18F-FET) PET and MRI were performed on 61 patients (38 men – 23 women, mean age 38 years) with histologically confirmed glioma WHO grade II. We evaluated initial 18F-FET uptake, morphologic tumor features in MRI and therapeutic parameters (initial biopsy vs. cytoreduction). Statistical endpoints were clinical or radiologic tumor progression, malignant transformation to high-grade glioma and death. FET uptake with a maximum tumor/brain ratio of ≥1.6 was rated as positive.

Results: The median observation time reached 85 months (range 2–216 months). Initial tumor diagnosis was confirmed by biopsy (n = 34) or operation with cytoreduction (n = 27) and histology revealed 48 astrocytomas, 7 oligoastrocytomas and 6 oligodendrogliomas WHO grade II. The median progression free survival (PFS) of the group was 27 months, the median overall survival (OAS) 45 months. FET-uptake: In the majority of patients (n = 46) the initial PET showed a FET positive tumor. During the further course a malignant transformation was diagnosed in 18 (39%), PFS was 23.5 months, OAS 39 months. In 15 patients the tumor was FET negative. In one (7%) a malignant transformation was observed, PFS reached 57 months, OAS 64.5 months (pPFS = 0.02; pOAS = 0.01). MRI features: A diffuse tumor was diagnosed in 16 patients. In 8 (50%) malignant transformation was observed, PFS was 21 months, OAS 39 months. 42 patients showed a circumscribed tumor. In 11 (26%) a malignant transformation was observed, PFS reached 31 months, OAS 58 months (p value was not significant). Cytoreduction: 10 patients (37%) presented a tumor malignization in the course of therapy; neither PFS (28 vs. 26 months) nor OAS (45 vs. 47 months) showed a significant difference between the resection and the biopsy group.

Conclusions: While cytoreductive surgery (vs. biopsy only) at the time of first diagnosis seems to have no benefit for patients outcome, the morphologic and metabolic aspects of initial MRI and 18F-FET PET are strong prognostic predictors in low-grade glioma. A diffuse tumor with an early amino-acid uptake is at high risk for early progression, malignant transformation and death. In contrast circumscribed tumors with low initial 18F-FET uptake exhibit a long and stable course with late progress into a high-grade glioma.