Study Design for Early vs Late Positron Emission Tomography (PET)
cognitive impairment, dementia, MCI, cognitive stage, AD, cerebrovascular disease
DEMENTIA WITH LEWY BODIES, RECRUITMENT, FRONTOTEMPORAL LOBAR DEGENERATION
Tan boxes indicate features of the study design not presented in the current work. The 13-month visit, the follow-up amyloid PET (to test the hypothesis that amyloid load is stable over 12-18 months), and the corresponding 18-month visit for arm 1 were made optional for logistic reasons. These measures were put in place to keep the end of the study timeline despite a prolonged recruitment (originally planned to be completed by June 30, 2020), which was granted to the recruiting memory clinics when in spring 2020 the COVID-19 pandemic brought recruitment to a complete halt.All AMYPAD-DPMS participants underwent up to 5 clinical visits: screening and baseline, and after 3, 6, 13, and 18 months (only for arm 1, not mandatory). During these visits, sociodemographic and clinical variables were collected, including cognitive stage, etiological diagnosis, diagnostic confidence, and treatment plan. The managing physicians indicated cognitive stage (ie, SCD plus clinical features increasing the likelihood of preclinical AD [SCD+], mild cognitive impairment [MCI], dementia) and etiological diagnoses (eg, AD, cerebrovascular disease, frontotemporal lobar degeneration, dementia with Lewy bodies), rated diagnostic confidence (by ticking the percentage corresponding to their appraisal of the diagnostic confidence on a visual numeric scale made of percentages organized spatially from 50% to 100% with incremental 5% intervals), and defined the treatment plan for each participant at each visit. In the current work, we focus only on the baseline and 3-month follow-up as related to the assessment of the primary outcome.Participants underwent amyloid PET with either [18F]flutemetamol (Vizamyl, GE Healthcare) or [18F]florbetaben (Neuraceq, Life Molecular Imaging) as amyloid PET tracers. Because AMYPAD-DPMS focuses on routine clinical practice, amyloid PET images were visually assessed by trained local nuclear medicine physicians using agency-approved reading methods for the 2 tracers. Assessment was performed using local software and workstations and in combination with structural imaging, if available.