title: Quantitative evaluation of L-[methyl-C-11] methionine uptake in tumor using positron emission tomography.
abstract: Tumor uptake of L-[methyl-11C]methionine ([11C]Met) was assessed in six patients with brain tumors and three patients with lung cancer using positron emission tomography (PET). In arterial plasma samples taken at 5, 15, 30, and 60 min after injection, a fraction of [11C]Met was measured using high performance liquid chromatography in individual patients. Employing curve fitting, a history of [11C]Met activity was obtained as an input function. By means of sequential PET scannings and graphic analysis, uptake rate and distribution volume of [11C]Met in tumor tissue were calculated. In two studies irreversible uptake into the tumors was not seen when total plasma 11C activity was used as the input; however when [11C]Met plasma activity was used, definite irreversible uptake was seen, indicating tumor viability. In other studies, up to 24% underestimation of uptake rate was found. The present results demonstrated the importance of measuring [11C]Met in plasma for quantitative assessment of in vivo amino acid metabolism in tumors.
authors: Department of Neurosurgery, Tohoku University, School of Medicine, Japan.
authors: J
authors: J
authors: Hatazawa
authors: K
authors: K
authors: Ishiwata
authors: M
authors: M
authors: Itoh
authors: M
authors: M
authors: Kameyama
authors: K
authors: K
authors: Kubota
authors: T
authors: T
authors: Ido
authors: T
authors: T
authors: Matsuzawa
authors: T
authors: T
authors: Yoshimoto
authors: S
authors: S
authors: Watanuki
authors: S
authors: S
authors: Seo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism*; D002250:Carbon Radioisotopes; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D008657:Metabolic Clearance Rate; D008715:Methionine / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics / Q000031:analogs & derivatives; D008875:Middle Aged; D013997:Time Factors; D014055:Tomography, Emission-Computed
chemical_list: D002250:Carbon Radioisotopes; D008715:Methionine; C038344:methionine methyl ester