Impact of Amyloid PET Imaging in the Memory Clinic: A Systematic Review and Meta-Analysis

Background: Patients with cognitive impairment or dementias of uncertain etiology are frequently referred to a memory disorders specialty clinic. The impact of and role for amyloid PET imaging (A beta-PET) may be most appropriate in this clinical setting. Objective: The primary objective of this studywas to perform a systematic reviewand meta-analysis of the impact of A beta-PET on etiological diagnosis and clinical management in the memory clinic setting. Methods: A search of the literature on the impact of A beta-PET in the memory clinic setting between 1 January 2004 and 12 February 2018 was conducted. Meta-analysis using a random effects model was performed to determine the pooled estimate of the impact of A beta-PET in the changes of diagnoses and changes in management plan. Results: After rigorous review, results from 13 studies were extracted, involving 1,489 patients. Meta-analysis revealed a pooled effect of change in diagnoses of 35.2% (95% CI 24.6-47.5). Sub-analyses showed that the pooled effect in change in diagnoses if A beta-PET was used under the appropriate use criteria (AUC) or non-AUC criteria were 47.8% (95% CI 25.9-70.5) and 29.6% (95% CI: 21.5-39.3), respectively. The pooled effect of a change of diagnosis from Alzheimer's disease (AD) to non-AD and from non-AD to AD were 22.7% (95% CI: 17.1-29.5) and 25.6% (95% CI: 17.6-35.8), respectively. The pooled effect leading to a change of management was 59.6% (95% CI 39.4-77.0). Conclusions: A beta-PET has a highly significant impact on both changes in diagnosis and management among patients being seen at a specialty memory clinic.