The primary objectives of this study were to: 1) obtain additional information regarding the safety of the
administration of 18F-AV-45 in healthy volunteers and subjects with AD; 2) evaluate two dose levels of 18F AV 45:
111 MBq (3 mCi) and 370 MBq (10 mCi) in healthy volunteers and subjects with AD, and; 3) obtain data regarding
the metabolism and clearance of 18F-AV-45.
Twenty subjects were enrolled in this study: 9 subjects (5 with AD and 4 control subjects) received a single injection of 111 MBq (3 mCi) and 11 (4 with AD and 7 control subjects) received 370 MBq (10 mCi) of 18F-AV-45.
Blood clearance and metabolite results showed that 18F-AV-45 is rapidly eliminated from circulation, with less than 5% of the injected 18F-radioactivity remaining by 20 minutes post-injection. Most of the 18F remaining in circulation was in the form of polar metabolites of 18F-AV-45. The blood clearance of 18F, following administration of 18F-AV-45, was found to be similar for healthy control subjects and AD subjects.
Visual assessments of the PET image quality for the 370 MBq dose group were slightly better than the 111 MBq
dose group, however, there was no difference in blinded reader ability to identify high and low amyloid burden
at the two dose levels. For both the 111 MBq and 370 MBq doses, subjects with AD showed a clear separation
between cortical and cerebellar activity within 15 minutes of dose administration; cognitively normal controls did
not show separation of cortical and cerebellar time activity curves. There were no significant differences in SUVR results for images acquired between 30 and 90 minutes post-injection for either dose group for AD and control
subjects. The numerical optimum timeframe for cortical SUVR results in AD subjects was reached by 40 minutes
post-injection and was constant for the remainder of the imaging session.