Human biodistribution and dosimetry of the D2/3 agonist 11C-N-propylnorapomorphine (11C-NPA) determined from PET.
We measured the whole-body distribution of intravenously injected (11)C-N-propylnorapomorphine ((11)C-NPA), a dopamine agonist PET tracer, in human subjects and determined the resulting absorbed radiation doses.


METHODS
Six subjects (3 women, 3 men) were injected with (11)C-NPA (nominal dose, 370 MBq). A total of 9 consecutive whole-body PET scans were obtained for each subject. In addition, time-activity curves for 12 organs were determined, and residence times were computed for each subject. Dosimetry was determined for the various body organs and the whole body.


RESULTS
The average NPA whole-body radiation dose was 3.17 x 10(-3) mSv per MBq of injected (11)C-NPA. The organ receiving the highest dose was the gallbladder wall, with an average of 2.81 x 10(-2) mSv.MBq(-1).


CONCLUSIONS
On the basis of averaged dosimetry results, an administration of less than 1,780 MBq (<48 mCi) of (11)C-NPA yields an organ dose of under 50 mSv (5 rem) to all organs.
Laymon
Charles M
CM
Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. CML14@pitt.edu
Mason
N Scott
NS
Frankle
W Gordon
WG
Carney
Jonathan P
JP
Lopresti
Brian J
BJ
Litschge
Maralee Y
MY
Mathis
Chester A
CA
Mountz
James M
JM
Narendran
Rajesh
R
D001058:Apomorphine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D001822:Body Burden; D002250:Carbon Radioisotopes / Q000008:administration & dosage / Q000493:pharmacokinetics; D065127:Dopamine D2 Receptor Antagonists; D005260:Female; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D009928:Organ Specificity; D049268:Positron-Emission Tomography / Q000379:methods*; D011874:Radiometry; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000493:pharmacokinetics; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D050637:Receptors, Dopamine D3 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014018:Tissue Distribution; D014915:Whole-Body Counting / Q000379:methods*
D002250:Carbon Radioisotopes; D065127:Dopamine D2 Receptor Antagonists; D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; C009074:N-n-propylnorapomorphine; D001058:Apomorphine