The effect of aromatic fluorine substitution in l-DOPA on the in vivo behaviour of [18F]2-, [18F]5- and [18F]6-fluoro-l-DOPA in the human brain

Remarkable differences in the human in vivo behaviour of each of the three [18F]-labelled ring fluorinated isomers of l-dihydroxyphenylalanine (l-DOPA) are presented. Unlike [18F]2-fluoro-l-DOPA, which did not appear to cross the blood brain barrier, [18F]5-fluoro-l-DOPA appears to be taken up and cleared from the cerebellum and the striata. In contrast with the 2- and 5-fluoro isomers of l-DOPA, radioactivity derived after injection of …