Incremental diagnostic value of 18F-Fluetemetamol PET in differential diagnoses of Alzheimer’s Disease-related neurodegenerative diseases from an unselected memory clinic cohort

Abstract

To evaluate the incremental diagnostic value of 18F-Flutemetamol PET following MRI measurements on an unselected prospective cohort collected from a memory clinic. A total of 84 participants was included in this study. A stepwise study design was performed including initial analysis (based on clinical assessments), interim analysis (revision of initial analysis post-MRI) and final analysis (revision of interim analysis post-18F-Flutemetamol PET). At each time of evaluation, every participant was categorized into SCD, MCI or dementia syndromal group and further into AD-related, non-AD related or non-specific type etiological subgroup. Post 18F-Flutemetamol PET, the significant changes were seen in the syndromal MCI group (57%, p < 0.001) involving the following etiological subgroups: AD-related MCI (57%, p < 0.01) and non-specific MCI (100%, p < 0.0001); and syndromal dementia group (61%, p < 0.0001) consisting of non-specific dementia subgroup (100%, p < 0.0001). In the binary regression model, amyloid status significantly influenced the diagnostic results of interim analysis (p < 0.01). 18F-Flutemetamol PET can have incremental value following MRI measurements, particularly reflected in the change of diagnosis of individuals with unclear etiology and AD-related-suspected patients due to the role in complementing AD-related pathological information.

Incremental value of amyloid PET in a tertiary memory clinic setting in China

“…11,12,[29][30][31] A total of 15.7% of participants had received further ancillary investigations, especially tau PET, which was often used to confirm AD etiology in amyloid-positive cases and to detect non-AD tauopathies in amyloid-negative cases. 32 Compared to previous Chinese studies, the overall impact on diagnostic change in our study appears to be relatively lower, [19][20][21] although these findings in other countries were highly variable, ranging from 19% to 79%. 33 This might be due to differences in study design There were more than half of the dementia patients in our study.…”

“…The high proportion of patients with uncertain dementia was recruited in Bao et al. study 21 . Whereas we opted to use an unselected memory clinic sample, rather than imposing restrictive inclusion and exclusion criteria, which may account for the lower proportional change.…”

“…According to a large prospective multicenter study, the Aβ‐PET has emerged as a valuable diagnostic tool in routine clinical practice, with 61.5% of patients exhibiting cognitive impairment experiencing a change in treatment and 35.6% experiencing an alteration of etiologic diagnosis as a result 13 . The clinical utility of Aβ‐PET has been systematically studied in many other countries, 11–13,15,18 whereas only a few studies with small sample sizes were performed in Chinese population 19–21 . The diagnosis was changed in more than 30% of patients with dementia after considering 18 F‐FDG with or without PiB results 19,20 .…”

“…The diagnosis was changed in more than 30% of patients with dementia after considering 18 F‐FDG with or without PiB results 19,20 . A recent study has shown that 18 F‐flutemetamol PET showed added value in Chinese patients, particularly reflected in the change of diagnosis of individuals with unclear etiology and AD‐suspected patients 21 . However, due to the lack of conclusive evidence supporting its clinical impact and the uniqueness of the medical insurance system in China, Aβ‐PET has yet to be reimbursed by the Chinese medical insurance system.…”

“…Shea et al and Liu et al analyzed the value of amyloid PET combined with FDG-PET in cognitive impairment diagnosis 19,20. The high proportion of patients with uncertain dementia was recruited in Bao et al study 21. Whereas we opted to use an unselected memory clinic sample, rather than imposing restrictive inclusion and exclusion criteria, which may account for the lower proportional change.F I G U R E 3 Change in diagnostic confidence with the added information from the visual read of the amyloid PET scan in the whole sample.…”