Comparative diagnostic accuracy of contrast-enhanced MRI and ^sup 18^F-FDOPA PET-CT in recurrent glioma

To compare the diagnostic accuracy of contrast enhanced magnetic resonance imaging (Ce-MRI) and ^sup 18^F-fluorodopa (^sup 18^F-FDOPA) positron emission tomography (PET)-computed tomography (CT) for detecting recurrent glioma. In this prospective study, 35 patients (age, 36.62±0.86 years; 80 % male) with histopathologically proven glioma with clinical suspicion of recurrence were evaluated using Ce-MRI and ^sup 18^F-FDOPA PET-CT. ^sup 18^F-FDOPA PET-CT images were evaluated qualitatively and semi-quantitatively. Combination of clinical follow-up (minimum 1 year), repeat imaging and/or biopsy (when available) was taken as the reference standard. Based on the reference standard, 26 patients were positive and nine were negative for recurrence. The sensitivity, specificity and accuracy of Ce-MRI were 92.3 %, 44.4 % and 80 % respectively, whereas those of ^sup 18^F-FDOPA PET-CT were 100 %, 88.89 % and 97.1 % respectively. Results of Ce-MRI and ^sup 18^F-FDOPA PET-CT were concordant in 74.3 % (29/35) and discordant in 17.1 % of patients (6/35). On McNemar analysis the difference was not statistically significant overall (P=0.687), for high-grade tumour (P=0.5) or low-grade tumours (P=1.0). However, ^sup 18^F-FDOPA PET-CT was more specific than Ce-MRI overall (P=0.0002), for high-grade tumour (P=0.006) and low-grade tumours (P=0.004). F-FDOPA PET-CT shows a high but comparable diagnostic accuracy to Ce-MRI for the detection of recurrent glioma. However, it is more specific than Ce-MRI. * Recurrent glioma in the postoperative site remains a diagnostic dilemma. * ^sup 18^ F-FDOPA PET-CT shows high diagnostic accuracy for detecting recurrent glioma. * Diagnostic accuracies for ^sup 18^ F-FDOPA PET-CT and contrast enhanced MRI are comparable. * However, ^sup 18^ F-FDOPA PET-CT is more specific than Ce-MRI for recurrent glioma. [PUBLICATION ABSTRACT]