Background: Early and correct diagnosis of tumor recurrence and its differentiation from therapy-related changes is crucial for prompt and adequate management of glioma patients. The purpose of this study was to compare the efficacies of Tc-99m glucoheptonate (GHA) single photon emission tomography (SPECT) and F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in detection of recurrence in patients with glioma.
Methods: A total of 90 patients with histopathologically proven glioma who had suspicion of recurrence clinically or on magnetic resonance imaging were evaluated using Tc-99m GHA SPECT and FDG PET/CT. Combination of clinical follow-up, repeat imaging, and biopsy (when available) was taken as gold standard.
Results: On the basis of gold standard, 59 patients were positive and 31 were negative for tumor recurrence. The sensitivity, specificity, and accuracy of GHA SPECT were 85%, 97%, and 89%, respectively, whereas those of FDG PET/CT were 70%, 97%, and 80%, respectively. On subgroup analysis, GHA SPECT performed better than FDG PET/CT in all grades except for grade II gliomas, where both were equally effective. In all, 15 patients had intermodality discordance, with GHA SPECT being correct in 13 of them.
Conclusions: GHA SPECT appears to be a better imaging modality than FDG PET/CT for detection of recurrent gliomas.