title: Whole-body biodistribution and estimation of radiation-absorbed doses of the dopamine D1 receptor radioligand 11C-NNC 112 in humans.
abstract: The present study estimated radiation-absorbed doses of the dopamine D(1) receptor radioligand [(11)C]((+)-8-chloro-5-(7-benzofuranyl)-7-hydroxy-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine) (NNC 112) in humans, based on dynamic whole-body PET in healthy subjects.
  
  
  METHODS
  Whole-body PET was performed on 7 subjects after injection of 710 +/- 85 MBq of (11)C-NNC 112. Fourteen frames were acquired for a total of 120 min in 7 segments of the body. Regions of interest were drawn on compressed planar images of source organs that could be identified. Radiation dose estimates were calculated from organ residence times using the OLINDA 1.0 program.
  
  
  RESULTS
  The organs with the highest radiation-absorbed doses were the gallbladder, liver, lungs, kidneys, and urinary bladder wall. Biexponential fitting of mean bladder activity demonstrated that 15% of activity was excreted via the urine. With a 2.4-h voiding interval, the effective dose was 5.7 microSv/MBq (21.1 mrem/mCi).
  
  
  CONCLUSIONS
  (11)C-NNC 112 displays a favorable radiation dose profile in humans and would allow multiple PET examinations per year to be performed on the same subject.
authors.affiliation: Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892-0135, USA. cropleyv@mail.nih.gov
authors.forename: Vanessa L
authors.initials: VL
authors.lastname: Cropley
authors.forename: Masahiro
authors.initials: M
authors.lastname: Fujita
authors.forename: John L
authors.initials: JL
authors.lastname: Musachio
authors.forename: Jinsoo
authors.initials: J
authors.lastname: Hong
authors.forename: Subroto
authors.initials: S
authors.lastname: Ghose
authors.forename: Janet
authors.initials: J
authors.lastname: Sangare
authors.forename: Pradeep J
authors.initials: PJ
authors.lastname: Nathan
authors.forename: Victor W
authors.initials: VW
authors.lastname: Pike
authors.forename: Robert B
authors.initials: RB
authors.lastname: Innis
mesh_terms: D000328:Adult; D001552:Benzazepines / Q000493:pharmacokinetics*; D001572:Benzofurans / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D009928:Organ Specificity; D049268:Positron-Emission Tomography / Q000379:methods*; D011829:Radiation Dosage; D011869:Radioligand Assay; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D014018:Tissue Distribution; D051598:Whole Body Imaging / Q000379:methods*; D014915:Whole-Body Counting / Q000379:methods*
chemical_list: D001552:Benzazepines; D001572:Benzofurans; D019275:Radiopharmaceuticals; D017447:Receptors, Dopamine D1; C077123:NNC 112