Background: Differentiation between recurrence and radiation necrosis in patients with glioma is crucial, as the two entities have completely different management and prognosis. The purpose of this study was to compare the efficacies of glucoheptonate (GHA) single photon emission computed tomography (SPECT) and contrast-enhanced MRI in the detection of recurrent glioma.
Methods: Eighty-five patients with histopathologically proven glioma with a clinical suspicion of recurrence were evaluated using Tc-99m GHA SPECT and MRI. A combination of clinical follow-up, repeat imaging and/or biopsy (when available) was taken as a gold standard.
Results: On the basis of the gold standard, 56 patients were positive and 29 were negative for tumour recurrence. The sensitivity, specificity and accuracy of GHA SPECT were 86.5, 96.5 and 89.4% respectively, whereas those of MRI were 94.6, 24.1 and 70.5% respectively. On subgroup analysis GHA SPECT had similar sensitivities with a much higher specificity than MRI across all grades. Thirty patients had intermodality discordance, with GHA SPECT being correct in 23 of them.
Conclusion: GHA SPECT seems to be a highly sensitive and specific imaging modality for the detection of recurrent gliomas compared with contrast-enhanced MRI.