Positron emission tomography quantification of [ 11 C]-DASB binding to the human serotonin transporter: modeling strategies. J Cereb Blood Flow Metab

methylaminomethyl-phenylsulfanyl)-benzonitrile, is a new highly selective radioligand for the in vivo visualization of the serotonin transporter (SERT) using positron emission tomog-raphy (PET). The current study evaluates different kinetic mod-eling strategies for quantification of [11C]-DASB binding in five healthy humans. Kinetic analyses of tissue data were per-formed with a one-tissue (1CM) and a two-tissue (2CM) com-partment model. Time-activity curves were well described by a 1CM for all regions. A 2CM model with four parameters failed to converge reliably. Reliable fits of the data were obtained only if no more than three parameters were allowed to vary. However, even then, the rate constants k3 and k4 were esti-mated with poor precision. Only the ratio k3/k4 was stable. Goodness of fit was not improved by using a 2CM as compared with a 1CM. The minimal study duration required to obtai