Biodistribution and radiation dosimetry in humans of [¹¹C]FLB 457, a positron emission tomography ligand for the extrastriatal dopamine D₂ receptor

Nucl Med Biol. 2014 Jan;41(1):102-5. doi: 10.1016/j.nucmedbio.2013.08.008. Epub 2013 Sep 26.

Abstract

Purpose: [(11)C]FLB 457, a radioligand with very high affinity and selectivity for dopamine D2/3 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 [(11)C]FLB 457 in healthy human subjects.

Methods: Whole-body images were acquired for 2 h after an injection of [(11)C]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 [(11)C]FLB 457 is 5.9 μSv/MBq, similar to those of other (11)C-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.

Keywords: Dopamine D(2) receptors; Dosimetry; Positron emission tomography; [(11)C]FLB 457.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Humans
  • Ligands
  • Male
  • Neostriatum / diagnostic imaging*
  • Neostriatum / metabolism*
  • Positron-Emission Tomography / methods*
  • Pyrrolidines / pharmacokinetics*
  • Radiometry
  • Receptors, Dopamine D2 / metabolism*
  • Salicylamides / pharmacokinetics*
  • Tissue Distribution

Substances

  • Ligands
  • Pyrrolidines
  • Receptors, Dopamine D2
  • Salicylamides
  • FLB 457