Detection of malignant tumors: Whole-body PET with fluorine 18 alpha-methyl tyrosine versus FDG - Preliminary study

PURPOSE: To compare the diagnostic potential of whole-body positron emissio n tomography (PET) with fluorine 78 alpha -methyltyrosine (FMT) with that o f whole-body PET with 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG). MATERIALS AND METHODS: Nineteen patients with or suspected of having malign ant tumors and five healthy volunteers underwent whole-body PET with FMT an d FDG. RESULTS: in comparison with FDG uptake, FMT uptake was significantly less i n the brain, heart, lung, liver, and spine. On a lesion-by-lesion basis, th e sensitivity of whole-body FMT PET for depicting malignant tumors was infe rior to that of whole-body FDG PET, but this difference was not statistical ly significant (74% [26 of 35 lesions] vs 91% [32 of 35 lesions], P > .05). The positive predictive value of FMT PET was superior to that of FDG PET ( 87% [26 of 30 lesions] vs 63% [32 of 51 lesions], P < .001). The difference in uptake between benign and malignant lesions was significant with FMT PE T (mean +/- SD, 1.64 +/- 0.96 vs 0.79 +/- 0.23; P < .001)but not with FDG P ET (5.02 +/- 3.56 vs 4.02 +/- 2.90, P < .05). CONCLUSION: Whole-body FMT PET is clinically useful in the diagnosis of mal ignant tumors and may be effective in the depiction of primary and metastat ic lesions in the cardiac region or in the brain.