BRAIN-TUMORS - L-[1-C-11]TYROSINE PET FOR VISUALIZATION AND QUANTIFICATION OF PROTEIN-SYNTHESIS RATE

PURPOSE: Positron emission tomography (PET) with the amino acid tracer L-[1-C-11]-tyrosine was evaluated in 27 patients with primary and rec urrent brain tumors. MATERIALS AND METHODS: Patients underwent either static (n = 14) or dynamic PET (n = 13), with quantification of protei n synthesis rate (PSR) and tumor-to-background ratio. Findings were co mpared with histologic findings. RESULTS: Primary brain tumor was prov ed in 22 patients histologically, as well as metastatic cancer of unkn own origin, primary non-Hodgkin lymphoma, meningioma, atypical infarct ion, and vasculitis in one patient each. At PET, 20 of 22 primary tumo rs, the metastasis, and non-Hodgkin lymphoma were correctly depicted. A false-positive finding was obtained with the infarction, and the men ingioma and vasculitis were not depicted. The calculated sensitivity w as 92%; specificity, 67%; and accuracy, 89%. There were no statistical ly significant relationships between histologic findings, PSR, and tum or-to-background ratio. CONCLUSION: L-[1-C-11]-tyrosine is a valid tra cer for diagnosis of brain tumors and allowed quantification of PSR.