title: Comparison of the accumulation kinetics of L-(methyl-11C)-methionine and D-(methyl-11C)-methionine in brain tumors studied with positron emission tomography.
abstract: Five patients with glioma were examined with positron emission tomography after the administration of 11C-L-methionine and at a following day with 11C-D-methionine. The rates of accumulation of the tracers were determined in the tumor and in the normal brain tissue according to a graphical technique of Patlak et coll. The accumulation rates for L-methionine were on the average 2.4 times higher than those of D-methionine in the tumors. The corresponding ration for normal brain tissue was 2.3. It is concluded that in this group of tumors without obvious blood-tumor-barrier breakdown, a stereospecific process with similar properties as in the normal brain tissue, is responsible for the accumulation of the labelled methionine.
mesh_terms: D001254:Astrocytoma / Q000097:blood / Q000000981:diagnostic imaging / Q000378:metabolism*; D001812:Blood-Brain Barrier; D001932:Brain Neoplasms / Q000097:blood / Q000000981:diagnostic imaging / Q000378:metabolism*; D002250:Carbon Radioisotopes; D006801:Humans; D007700:Kinetics; D008715:Methionine / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism; D009837:Oligodendroglioma / Q000097:blood / Q000000981:diagnostic imaging / Q000378:metabolism; D014055:Tomography, Emission-Computed
chemical_list: D002250:Carbon Radioisotopes; D008715:Methionine; C038344:methionine methyl ester