L-amino acid load to enhance PET differentiation between tumor and inflammation: an in vitro study on (18)F-FET uptake.
Labeled amino acids (AA) are tumor tracers for use in nuclear medecine. O-(2-[(18)F]fluoroethyl)-L-tyrosine (FET) is transported by the L-system, known to function as an exchanger. In vitro utilization of FET, after a preload or prior to an afterload of non radioactive L-amino acids, was evaluated in order to measure the potential effects of AA content on the distinction between tumor and inflammatory lesions. Cellular uptake of FET was studied on rat osteosarcoma cells (ROS 17/2.8) and human leukocytes, initially loaded with nonradioactive L-tyrosine or L-methionine. FET efflux was evaluated from cells loaded with nonradioactive L-phenylalanine after tracer uptake. ROS 17/2.8 showed a higher sensitivity to preload and afterload effects on cellular FET content as compared with the leukocytes. We conclude that preload with L-tyrosine, prior to the administration of FET, may be a potential procedure to improve PET differentiation between tumor and inflammatory lesions.
Laïque
S
S
PET/Biomedical Cyclotron Unit and Department of Nuclear Medicine, ULB-Hôpital Erasme, 808 route de Lennik, 1070 Brussels, Belgium. salma.laique@ulb.ac.be
Egrise
D
D
Monclus
M
M
Schmitz
F
F
Garcia
C
C
Lemaire
C
C
Luxen
A
A
Goldman
S
S
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D003937:Diagnosis, Differential; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D007249:Inflammation / Q000175:diagnosis*; D007962:Leukocytes / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D009369:Neoplasms / Q000175:diagnosis*; D010649:Phenylalanine / Q000378:metabolism; D049268:Positron-Emission Tomography / Q000379:methods*; D051381:Rats; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000493:pharmacokinetics
D000596:Amino Acids; C117289:O-(2-fluoroethyl)tyrosine; D019788:Fluorodeoxyglucose F18; D014443:Tyrosine; D010649:Phenylalanine; D008715:Methionine