Acute changes in glucose uptake after treatment: the effects of carmustine (BCNU) on human glioblastoma multiforme

Sequential positron emission tomographic scans with [18F]-2-fluorodeoxyglucose (PET-FDG) were performed on 6 patients with glioblastoma multiforme who were treated with adjuvant BCNU. Scans were acquired before and 24 hours after BCNU. All patients had prior brain irradiation. Ratios between the maximal tumor FDG uptake and the contralateral white matter FDG uptake, the glucose uptake ratio, were determined. Percent changes in the glucose uptake ratio between the baseline scan and the 24 hour post-treatment scan were of prognostic significance. Patients with the largest percent changes in FDG uptake had the shortest survival. In contrast, neither the baseline glucose uptake ratio nor the visual tumor grade accurately predicted length of survival.