Serial FDG-PET studies in the prediction of survival in patients with primary brain tumors.

Objective: This study examines the changes in tumor [18F]fluoro-2-deoxyglucose (FDG) uptake on serial FDG-PET studies and the ability of serial FDG-PET studies to predict survival in patients with treated and untreated primary brain tumors.

Materials And Methods: The study population included 20 patients with primary brain tumors. Changes in FDG uptake over time were visually assessed and correlated with clinical course and survival.

Results: Although little change in FDG uptake was noted for individual patients, high average FDG uptake (greater than or equal to gray matter) on serial studies was associated with shorter survival. Patients with persistently low FDG uptake (less than gray matter) survived significantly longer than patients with persistently high FDG uptake (p = 0.007).

Conclusion: Serial evaluation of metabolic activity with PET may provide more accurate prognostic information than a single FDG uptake determination in patients with primary brain tumors.