Comparative study of (18)F-DOPA, (13)N-Ammonia and F18-FDG PET/CT in primary brain tumors

AIM: To determine the diagnostic reliability of (18)F-FDOPA, (13)N-Ammonia and F18-FDG PET/CT in primary brain tumors. We evaluated the amino acid and glucose metabolism of brain tumors by using PET with (18)F-FDOPA, (13)N-Ammonia and F18-FDG PET/CT. MATERIALS AND METHODS: Nine patients undergoing evaluation for brain tumors were studied. Tracer uptake was quantified by the use of standardized uptake values and the ratio of tumor uptake to normal identical area of contra lateral hemisphere (T/N). In addition, PET uptake with (18)F-FDOPA was quantified by use of ratio of tumor uptake to striatum uptake (T/S). The results were correlated with the patient's clinical profile. RESULTS: Both high-grade and low-grade tumors were well visualized with (18)F-FDOPA. The sensitivity for identifying tumors was substantially higher with (18)F-FDOPA PET than with F18-FDG and (13)N-Ammonia PET as determined by simple visual inspection. The sensitivity for identifying recurrence in low grade gliomas is higher with (13)N-Ammonia than with F18-FDG. CONCLUSION: (18)F-FDOPA PET is more reliable than F18-FDG and (13)N-Ammonia PET for evaluating brain tumors.