Dexamethasone treatment and plasma glucose levels: relevance for fluorine-18-fluorodeoxyglucose uptake measurements in gliomas.

Abstract

The data suggest that DEX affects FDG uptake in malignant gliomas through interaction with cerebral blood vessels and extracellular space, whereas FDG metabolism in tumors is not influenced substantially. This is of practical importance for patients having serial brain tumor imaging for treatment evaluation because patients may receive different DEX doses at different time points in the course of their disease. By contrast, the plasma glucose level must be considered a confounding variable when SUVs, tumor-to-brain ratios or Ki are used for treatment evaluation.