Effects of hyperglycemia on FDG uptake in human brain and glioma.
This study evaluates the effects of hyperglycemia on fluorodeoxyglucose (FDG) uptake in the human brain and in brain tumors.


METHODS
We performed glucose loading during FDG PET studies in nine patients with brain tumors (eight gliomas and one brain metastasis) and one with resected glioma. Two FDG PET scans were obtained in all cases within 1 wk in a control state and with glucose loading by intravenous infusion of 10% glucose solution. Serial arterial blood sampling was performed in all cases to obtain fractional uptake of FDG normalized by the plasma integral uptake of radioactivity (FU).


RESULTS
In all nine patients with brain tumors, the tumor was depicted more clearly with glucose loading than in the control state. Glucose loading decreased FU in the cerebral cortex (54.2% +/- 13.8%) nearly in inverse proportion to the plasma glucose level, while the tumors showed a decrease (42.5% +/- 15.6%), resulting in an increased tumor-to-cortex ratio by 26.0% +/- 5.7%. Fractional uptake in the cerebellum, white matter and the edematous area also decreased by glucose loading (53.9% +/- 13.2%, 49.6% +/- 10.3% and 34.9% +/- 9.6%, respectively).


CONCLUSIONS
These results demonstrate the different effects of hyperglycemia on normal brain tissue and on tumor, suggesting that glucose loading may be a valuable adjunct to FDG PET to enhance detection of recurrent or residual brain tumors.
Department of Nuclear Medicine, Faculty of Medicine, Kyoto University, Japan.
K
K
Ishizu
S
S
Nishizawa
Y
Y
Yonekura
N
N
Sadato
Y
Y
Magata
N
N
Tamaki
T
T
Tsuchida
H
H
Okazawa
S
S
Miyatake
M
M
Ishikawa
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D001921:Brain / Q000000981:diagnostic imaging*; D001932:Brain Neoplasms / Q000097:blood / Q000000981:diagnostic imaging*; D003847:Deoxyglucose / Q000031:analogs & derivatives*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005910:Glioma / Q000097:blood / Q000000981:diagnostic imaging*; D005947:Glucose / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D014055:Tomography, Emission-Computed
D001786:Blood Glucose; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose; D005947:Glucose