Biodistribution and radiation dosimetry in humans of [C-11]FLB 457, a positron emission tomography ligand for the extrastriatal dopamine D-2 receptor

Purpose: [C-11]FLB 457, a radioligand with very high affinity and selectivity for dopamine D-2/3 receptors, is used to measure receptor binding in extrastriatal regions showing low density of the receptors. The purpose of this study was to estimate the whole-body biodistribution of radioactivity and the radiation absorbed doses to organs after intravenous injection of [C-11]FLB 457 in healthy human subjects. Methods: Whole-body images were acquired for 2 h after an injection of [C-11]FLB 457 in six healthy humans. Radiation absorbed doses were estimated by the MIRD scheme implemented in OLINDA/EXM 1.1 software. Results: Organs with the longest residence time were the liver, lungs, and brain. The organs with the highest radiation doses were the kidneys, liver, and pancreas. The effective dose delivered by [C-11]FLB 457 is 5.9 mu Sv/MBq, similar to those of other C-11-labeled tracers. Conclusions: This effective dose would allow multiple scans in the same individual based on prevailing maximum recommended-dose guidelines in the USA and Europe. (C) 2014 Elsevier Inc. All rights reserved.