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