18F-FDOPA PET/CT for detection of recurrence in patients with glioma: Prospective comparison with 18F-FDG PET/CT

Abstract

Purpose: Differentiation between recurrence and radiation necrosis in patients with glioma is crucial, since the two entities have completely different management and prognosis. The purpose of the present study was to compare the efficacies of 18F-FDG PET/CT and 3,4-dihydroxy-6-[ 18F]fluoro-phenylalanine (18F-FDOPA) PET/CT in detection of recurrent gliomas. Methods: A total of 28 patients (age 38.82 ± 1.25 years; 85.7 % men) with histopathologically proven glioma with clinical/imaging suspicion of recurrence were evaluated using 18F-FDG PET/CT and 18F-FDOPA PET/CT. 18F-FDG PET/CT and 18F-FDOPA PET/CT images were evaluated qualitatively and semiquantitatively. The combination of clinical follow-up, repeat imaging and/or biopsy (when available) was taken as the reference standard. Results: Based on the reference standard, 21 patients were positive and 7 were negative for tumour recurrence. The sensitivity, specificity and accuracy of 18F-FDG PET/CT were 47.6 %, 100 % and 60.7 %, respectively, and those of 18F-FDOPA PET/CT were 100 %, 85.7 % and 96.4 %, respectively. The results of 18F-FDG PET/CT and 18F-FDOPA PET/CT were concordant in 57.1 % of patients (16 of 28) and discordant in 42.9 % (12 of 28). The difference in the findings between 18F-FDG PET/CT and 18F-FDOPA PET/CT was significant (P = 0.0005, McNemar's test). The difference was significant for low-grade tumours (P = 0.0039) but not for high-grade tumours (P = 0.250). Conclusion: 18F-FDOPA PET/CT is highly sensitive and specific for detection of recurrence in glioma patients. It is superior to 18F-FDG PET/CT for this purpose and is especially advantageous in patients with low-grade gliomas. © 2013 Springer-Verlag Berlin Heidelberg.