title: 11C-methionine PET for differential diagnosis of low-grade gliomas.
abstract: Management of low-grade gliomas continues to be a challenging task, because CT and MRI do not always differentiate from nontumoral lesions. Furthermore, tumor extent and aggressiveness often remain unclear because of a lack of contrast enhancement. Previous studies indicated that large neutral amino acid tracers accumulate in most brain tumors, including low-grade gliomas, probably because of changes of endothelial and blood-brain barrier function. We describe 11C-methionine uptake measured with PET in a series of 196 consecutive patients, most of whom were studied because of suspected low-grade gliomas. Uptake in the most active lesion area, relative to contralateral side, was significantly different among high-grade gliomas, low-grade gliomas, and chronic or subacute nontumoral lesions, and this difference was independent from contrast enhancement in CT or MRI. Corticosteroids had no significant effect on methionine uptake in low-grade gliomas but reduced uptake moderately in high-grade gliomas. Differentiation between gliomas and nontumoral lesions by a simple threshold was correct in 79%. Recurrent or residual tumors had a higher uptake than primary gliomas. In conclusion, the high sensitivity of 11C-methionine uptake for functional endothelial or blood-brain barrier changes suggests that this tracer is particularly useful for evaluation and follow-up of low-grade gliomas.
authors.affiliation: Klinik für Neurologie, Universität zu Köln, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Herholz
authors.forename: T
authors.initials: T
authors.lastname: Hölzer
authors.forename: B
authors.initials: B
authors.lastname: Bauer
authors.forename: R
authors.initials: R
authors.lastname: Schröder
authors.forename: J
authors.initials: J
authors.lastname: Voges
authors.forename: R I
authors.initials: RI
authors.lastname: Ernestus
authors.forename: G
authors.initials: G
authors.lastname: Mendoza
authors.forename: G
authors.initials: G
authors.lastname: Weber-Luxenburger
authors.forename: J
authors.initials: J
authors.lastname: Löttgen
authors.forename: A
authors.initials: A
authors.lastname: Thiel
authors.forename: K
authors.initials: K
authors.lastname: Wienhard
authors.forename: W D
authors.initials: WD
authors.lastname: Heiss
mesh_terms: D000328:Adult; D001254:Astrocytoma / Q000000981:diagnostic imaging; D002250:Carbon Radioisotopes; D003937:Diagnosis, Differential; D005260:Female; D005909:Glioblastoma / Q000000981:diagnostic imaging; D005910:Glioma / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008715:Methionine / Q000378:metabolism*; D008875:Middle Aged; D009837:Oligodendroglioma / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
chemical_list: D002250:Carbon Radioisotopes; D008715:Methionine