RADIATION-DOSIMETRY OF [F-18] (N-METHYL)BENPERIDOL AS DETERMINED BY WHOLE-BODY PET IMAGING OF PRIMATES

Radiation absorbed doses due to IV administration of [F-18](N-methyl)b enperidol ([F-18]NMB) were estimated by whole-body PET imaging of nonh uman primates. Time-activity curves were obtained for nine compartment s (striatum, eyes, heart, lungs, liver, gallbladder, intestines, kidne ys, bladder) by using dynamic PET scans of three different baboons giv en the radiotracer. These time activity curves were used to calculate the residence times of radioactivity in these tissues. Human absorbed dose estimates were calculated using the updated MIRDOSE 3 S values an d assuming the same biodistribution. Based on an average of three stud ies, the critical organs were the lower large intestine, gallbladder, and liver, receiving doses of 585, 281, and 210 mrad/mCi, respectively . The brain received a dose of 13 mrad/mCi; other organs received dose s between 32-77 mrad/mCi. These results indicate that up to 8.5 mCi of [F-18]NMB can be safely administered to human subjects for PET studie s of D2 receptor binding. (C) 1997 Elsevier Science Inc.