Increased amino acid transport into brain tumors measured by PET of L-(2-18F)fluorotyrosine.
The uptake of L-(2-18F)fluorotyrosine (F-Tyr), a newly synthetized amino acid tracer, was studied in 15 patients with various brain tumors by dynamic PET. The higher F-Tyr accumulation in tumors (mean 27% above contralateral tissue) was associated with two-fold transport rates into tumors, while the rate constants describing irreversible incorporation were decreased. The increased F-Tyr transport was not correlated to 68Ga-EDTA accumulation and cannot be explained by disruption of the blood-brain barrier. Kinetic analysis of 2-(18F)-fluoro-deoxy-glucose accumulation in the same patients demonstrated that increased metabolic rates in tumors are mainly caused by altered phosphorylation rates while transport of glucose is less affected. Since F-Tyr transport rates clearly separated tumors from normal tissue and since F-Tyr accumulation was related to tumor grade, PET studies of F-Tyr uptake are of clinical value for diagnosis and classification of brain tumors.
Wienhard
K
K
Max-Planck-Institut für neurologische Forschung, Köln, Germany.
Herholz
K
K
Coenen
H H
HH
Rudolf
J
J
Kling
P
P
Stöcklin
G
G
Heiss
W D
WD
D000328:Adult; D000368:Aged; D001812:Blood-Brain Barrier / Q000187:drug effects; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism*; D003847:Deoxyglucose / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D004492:Edetic Acid / Q000493:pharmacokinetics; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D014055:Tomography, Emission-Computed; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D014443:Tyrosine; C060489:2-fluorotyrosine; D003847:Deoxyglucose; D004492:Edetic Acid