Whole-body biodistribution and estimation of radiation-absorbed doses of the dopamine D1 receptor radioligand 11C-NNC 112 in humans.
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.
Cropley
Vanessa L
VL
Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892-0135, USA. cropleyv@mail.nih.gov
Fujita
Masahiro
M
Musachio
John L
JL
Hong
Jinsoo
J
Ghose
Subroto
S
Sangare
Janet
J
Nathan
Pradeep J
PJ
Pike
Victor W
VW
Innis
Robert B
RB
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*
D001552:Benzazepines; D001572:Benzofurans; D019275:Radiopharmaceuticals; D017447:Receptors, Dopamine D1; C077123:NNC 112