Comparison of 18F-FET and 18F-FDG PET in brain tumors

Pauleit, Dirk; Stoffels, Gabriele; Bachofner, Ansgar; Floeth, Frank W.; Sabel, Michael; Herzog, Hans; Tellmann, Lutz; Jansen, Paul; Reifenberger, Guido; Hamacher, Kurt; Coenen, Heinz H.; Langen, Karl-Josef

doi:10.1016/j.nucmedbio.2009.05.005

« Previous Next »Nuclear Medicine and Biology
Volume 36, Issue 7 , Pages 779-787, October 2009

Comparison of ¹⁸F-FET and ¹⁸F-FDG PET in brain tumors

Dirk Pauleit
- Institute of Neuroscience and Medicine, Forschungszentrum Jülich, D-52425 Jülich, Germany
Gabriele Stoffels
- Institute of Neuroscience and Medicine, Forschungszentrum Jülich, D-52425 Jülich, Germany
Ansgar Bachofner
- Clinic of Nuclear Medicine, Heinrich-Heine-University, D-40001 Düsseldorf, Germany
Frank W. Floeth
- Department of Neurosurgery, Heinrich-Heine-University, D-40001 Düsseldorf, Germany
Michael Sabel
- Department of Neurosurgery, Heinrich-Heine-University, D-40001 Düsseldorf, Germany
Hans Herzog
- Institute of Neuroscience and Medicine, Forschungszentrum Jülich, D-52425 Jülich, Germany
Lutz Tellmann
- Institute of Neuroscience and Medicine, Forschungszentrum Jülich, D-52425 Jülich, Germany
Paul Jansen
- Institute of Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany
Guido Reifenberger
- Department of Neuropathology, Heinrich-Heine-University, D-40001 Düsseldorf, Germany
Kurt Hamacher
- Institute of Neuroscience and Medicine, Forschungszentrum Jülich, D-52425 Jülich, Germany
Heinz H. Coenen
- Institute of Neuroscience and Medicine, Forschungszentrum Jülich, D-52425 Jülich, Germany
Karl-Josef Langen
- Institute of Neuroscience and Medicine, Forschungszentrum Jülich, D-52425 Jülich, Germany
- Corresponding author. Tel.: +49 2461 61 5900, +49 2461 61 8261.

Received 19 March 2009; received in revised form 16 May 2009; accepted 19 May 2009. published online 30 July 2009.

Abstract

The purpose of this study was to compare the diagnostic value of positron emission tomography (PET) using [¹⁸F]-fluorodeoxyglucose (¹⁸F-FDG) and O-(2-[¹⁸F]fluoroethyl)-l-tyrosine (¹⁸F-FET) in patients with brain lesions suspicious of cerebral gliomas.

Methods

Fifty-two patients with suspicion of cerebral glioma were included in this study. From 30 to 50 min after injection of 180 MBq ¹⁸F-FET, a first PET scan (¹⁸F-FET scan) was performed. Thereafter, 240 MBq ¹⁸F-FDG was injected and a second PET scan was acquired from 30 to 60 min after the second injection (¹⁸F-FET/¹⁸F-FDG scan). The cerebral accumulation of ¹⁸F-FDG was calculated by decay corrected subtraction of the ¹⁸F-FET scan from the ¹⁸F-FET/¹⁸F-FDG scan. Tracer uptake was evaluated by visual scoring and by lesion-to-background (L/B) ratios. The imaging results were compared with the histological results and prognosis.

Results

Histology revealed 24 low-grade gliomas (LGG) of World Health Organization (WHO) Grade II and 19 high-grade gliomas (HGG) of WHO Grade III or IV, as well as nine others, mainly benign histologies. The gliomas showed increased ¹⁸F-FET uptake (>normal brain) in 86% and increased ¹⁸F-FDG uptake (>white matter) in 35%. ¹⁸F-FET PET provided diagnostically useful delineation of tumor extent while this was impractical with ¹⁸F-FDG due to high tracer uptake in the gray matter. A local maximum in the tumor area for biopsy guidance could be identified with ¹⁸F-FET in 76% and with ¹⁸F-FDG in 28%. The L/B ratios showed significant differences between LGG and HGG for both tracers but considerable overlap so that reliable preoperative grading was not possible. A significant correlation of tracer uptake with overall survival was found with ¹⁸F-FDG only. In some benign lesions like abscesses, increased uptake was observed for both tracers indicating a limited specificity of both techniques.

Conclusions

¹⁸F-FET PET is superior to ¹⁸F-FDG for biopsy guidance and treatment planning of cerebral gliomas. The uptake of ¹⁸F-FDG is associated with prognosis, but the predictive value is limited and a histological evaluation of tumor tissue remains necessary. Therefore, amino acids like ¹⁸F-FET are the preferred PET tracers for the clinical management of cerebral gliomas.

Keywords: Cerebral glioma, ¹⁸F-FDG, Amino acid PET, [¹⁸F]fluoroethyl-l-tyrosine