[(18)F]FDOPA and [(18)F]CFT are both sensitive PET markers to detect presynaptic dopaminergic hypofunction in early Parkinson's disease.
The aim of this study was to compare two PET ligands, 6-[(18)F]fluoro-L-dopa ([(18)F]FDOPA) and (18)F-labeled CFT, 2beta-carbomethoxy-3beta-(4-[(18)F]-fluorophenyl)tropane ([(18)F]CFT), in detecting presynaptic dopaminergic hypofunction in early Parkinson's disease (PD). These ligands reflect different aspects of presynaptic dopaminergic function, since [(18)F]FDOPA mainly reflects 6-[(18)F]fluorodopamine (fluorodopamine) synthesis and storage whereas [(18)F]CFT uptake is related to dopamine transporter function. Eight de novo patients with PD who had never been on antiparkinsonian medication were investigated with [(18)F]FDOPA and [(18)F]CFT PET. Five healthy volunteers were studied as controls. In PD patients, both [(18)F]FDOPA and [(18)F]CFT uptakes were significantly reduced both in the contralateral and ipsilateral anterior and posterior putamen. The reduction was greatest in the contralateral posterior putamen (to 28% of control mean for [(18)F]FDOPA, P < 0.0001 and to 16% for [(18)F]CFT, P < 0.0001). Individually, all patients' [(18)F]FDOPA and [(18)F]CFT uptake values in the contralateral anterior and posterior putamen were below 3 SD of the control mean. In the caudate nucleus, the mean uptake of both tracers was significantly reduced both ipsilaterally and contralaterally, but less severely than in the putamen (to 69% of the control mean for [(18)F]FDOPA, P = 0.003 and to 60% for [(18)F]CFT, P = 0.001 contralaterally). Our results show that both [(18)F]FDOPA as well as [(18)F]CFT sensitively detect presynaptic dopaminergic hypofunction in early PD. They demonstrate a considerable reduction of tracer uptake that is greatest in the posterior putamen, followed by the anterior putamen and the caudate nucleus.
Rinne
O J
OJ
Department of Neurology, University of Turku, Turku, Finland. juha.rinne@pet.tyks.fi
Nurmi
E
E
Ruottinen
H M
HM
Bergman
J
J
Eskola
O
O
Solin
O
O
D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000503:physiopathology; D002421:Caudate Nucleus / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D003042:Cocaine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004298:Dopamine / Q000032:analysis* / Q000378:metabolism; D015536:Down-Regulation / Q000502:physiology; D005260:Female; D005462:Fluorine Radioisotopes; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000503:physiopathology; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D017729:Presynaptic Terminals / Q000378:metabolism; D011699:Putamen / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D009435:Synaptic Transmission / Q000502:physiology
D005462:Fluorine Radioisotopes; C043437:fluorodopa F 18; C021279:(1R-(exo,exo))-3-(4-fluorophenyl)-8-methyl-8- azabicyclo(3.2.1)octane-2-carboxylic acid, methyl ester; D004295:Dihydroxyphenylalanine; D003042:Cocaine; D004298:Dopamine