Untreated glioblastoma multiforme: increased myo-inositol and glutamine levels in the contralateral cerebral hemisphere at proton MR spectroscopy.
OBJECTIVE
To use localized in vivo proton magnetic resonance (MR) spectroscopy of the contralateral hemisphere in patients with glioblastoma multiforme (GBM) to detect alterations in cerebral metabolites as potential markers of infiltrating GBM cells.


METHODS
The study was approved by the ethics committee, and written informed consent was obtained. Twenty-two patients with newly diagnosed and untreated GBM underwent in vivo single-voxel short echo time proton MR spectroscopy with a 3-T MR imaging system. Absolute metabolite concentrations in the hemisphere contralateral to the tumor were compared with data from five patients with low-grade gliomas (LGGs) and from a group of 14 age-matched control subjects by using analysis of variance and subsequent t tests or corresponding nonparametric tests.


RESULTS
In the contralateral hemisphere, MR spectroscopy revealed increased concentrations of myo-inositol and glutamine. Mean myo-inositol levels were significantly increased in patients with GBM (3.6 mmol/L +/- 0.8 [standard deviation]) relative to levels in control subjects (3.1 mmol/L +/- 0.6; P = .03) and tended to be higher relative to levels in patients with LGG (2.7 mmol/L +/- 0.8; P = .09). Mean glutamine concentrations in patients with GBM (3.4 mmol/L +/- 0.9) differed significantly from those in control subjects (2.7 mmol/L +/- 0.7; P = .01); mean concentrations in patients with GBM differed from those in patients with LGG (2.4 mmol/L +/- 0.5; P = .01). There were no significant differences between data in patients with LGG and in control subjects.


CONCLUSIONS
Increased concentrations of myo-inositol and glutamine in the contralateral normal-appearing white matter of GBM patients are consistent with mild astrocytosis and suggest the detectability of early neoplastic infiltration by using proton MR spectroscopy in vivo.
MR-Research in Neurology and Psychiatry, Department of Neuroradiology, Universitymedicine, Georg-August-Universität Göttingen, Robert-Koch-Strasse 40, 37099 Göttingen, Germany. kai.kallenberg@med.uni-goettingen.de
Kai
K
Kallenberg
Hans C
HC
Bock
Gunther
G
Helms
Klaus
K
Jung
Arne
A
Wrede
Jan-Hendrik
JH
Buhk
Alf
A
Giese
Jens
J
Frahm
Herwig
H
Strik
Peter
P
Dechent
Michael
M
Knauth
D000368:Aged; D001932:Brain Neoplasms / Q000378:metabolism* / Q000628:therapy; D016022:Case-Control Studies; D005260:Female; D005909:Glioblastoma / Q000378:metabolism* / Q000628:therapy; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D007294:Inositol / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric
D005973:Glutamine; D007294:Inositol