Beta-amyloid (Abeta) imaging has great potential to aid in the diagnosis of @entity195 and the development of therapeutics. The radiation dosimetry of Abeta radioligands may influence their application; therefore, we calculated and compared the @entity24882 ( @entity24882 ) of 11C-PiB and a new @entity8984 -labeled ligand, @entity40619 . METHODS: Attenuation-corrected whole-body scans were performed at 0, 15, 30, 45, and 60 min after injection of 350+/-28 MBq (mean+/-SD) of 11C-PiB in 6 subjects and at 0, 20, 60, 120, and 180 min after injection of 319+/-27 MBq of @entity40619 in 3 subjects. Coregistered CT was used to define volumes of interest (VOIs) on the PET images. The source organs were the brain, lungs, liver, kidneys, spleen, and vertebrae. The VOIs for the contents of the gallbladder, urinary bladder, lower large intestine, upper large intestine, and small intestine were also defined. Total activity in each organ at each time point was calculated by use of reference organ volumes. The resultant time-activity curves were fitted with constrained exponential fits, and cumulated activities were determined. A dynamic bladder voiding model was used. The OLINDA/EXM program was used to calculate the whole-body @entity24882 from the acquired data. RESULTS: For 11C-PiB, the highest absorbed doses were in the gallbladder wall (44.80+/-29.30 microGy/MBq), urinary bladder wall (26.30+/-8.50 microGy/MBq), liver (19.88+/-3.58 microGy/MBq), and kidneys (12.92+/-3.37 microGy/MBq). The @entity2613 was 5.29+/-0.66 microSv/MBq. For @entity40619 , the highest doses were also in the gallbladder wall (132.40+/-43.40 microGy/MBq), urinary bladder wall (24.77+/-7.36 microGy/MBq), and liver (39.07+/-8.31 microGy/MBq). The @entity2613 was 14.67+/-1.39 microSv/MBq. CONCLUSION: The estimated organ doses for 11C-PiB were comparable to those reported in earlier research. With the doses used in published studies (300-700 MBq), the @entity24882 would range from 1.6 to 3.7 @entity2073 . The @entity2613 of @entity40619 was 30% lower than that of @entity419 and, at the published dose of 300 MBq, would yield an @entity2613 of 4.4 @entity2073 . The dosimetry of both Abeta radioligands is suitable for clinical and research applications.

Radiation dosimetry of beta-amyloid tracers 11C-PiB and XXXX .

@entity8984 :: ('CHEBI:36939', 'Chemical') :: ['18F'] @entity24882 :: ('MESH:D065606', 'Disease') :: ['EDs', 'effective doses'] @entity419 :: ('MESH:D019788', 'Chemical') :: ['18F-FDG'] @entity40619 :: ('MESH:C527756', 'Chemical') :: ['18F-BAY94-9172'] @entity2613 :: ('MESH:C536181', 'Disease') :: ['ED'] @entity2073 :: ('10821', 'Species') :: ['mSv'] @entity195 :: ('MESH:D000544', 'Disease') :: ['Alzheimer disease']
@entity40619 :: (MESH:C527756,Chemical) :: ['18F-BAY94-9172']
