LOS ANGELESIn a retrospective study, F-18-fluorodeoxyglucose (FDG)- PET images of the brain predicted histological grade and survival in patients with gliomas (see images). At this time, FDG-PET appears to be better than pathological grading for this purpose, Vasantha Padma, MD, of the Wallace-Kettering Neurosciences Institute, Kettering, Ohio, said at the 49th Annual Meeting of the Society of Nuclear Medicine (abstract 400).
The investigators analyzed 331 PET scans of patients with histologically proven gliomas taken between 1990 and 2000. The images were graded on a scale from 0 to 3 (0 = no uptake of FDG and 3 = high uptake of FDG by visual inspection).
Results showed that 94% of the patients with low FDG uptake (0-1 on the scale) lived for more than 1 year, and 19% survived for more than 5 years. Of these patients, 86% had low-grade gliomas (grade I-II). In contrast, only 29% of the patients with high FDG uptake (scores of 2-3) lived for more than 1 year, and none survived for more than 5 years. Of these high-uptake patients, 94% had high-grade gliomas (grade III-IV).
Dr. Padma suggested that use of FDG-PET as a prognostic indicator could help with disease management by determining which glioma patients need immediate aggressive treatment.
Future research, she said, will investigate the co-registration of different functional modalities with structural imaging techniques, for more precise and accurate assessment of the location and magnitude of the tumor load, as well as the use of the newer PET radiotracers 11C-methionine and 11C-choline.