Disclosure of amyloid positron emission tomography results to individuals without dementia: a systematic review

Abstract

BackgroundDisclosure of amyloid positron emission tomography (PET) results to individuals without dementia has become standard practice in secondary prevention trials and also increasingly occurs in clinical practice. However, this is controversial given the current lack of understanding of the predictive value of a PET result at the individual level and absence of disease-modifying treatments. In this study, we systematically reviewed the literature on the disclosure of amyloid PET in cognitively normal (CN) individuals and patients with mild cognitive impairment (MCI) in both research and clinical settings.MethodsWe performed a systematic literature search of four scientific databases. Two independent reviewers screened the identified records and selected relevant articles. Included articles presented either empirical data or theoretical data (i.e. arguments in favor or against amyloid status disclosure). Results from the theoretical data were aggregated and presented per theme.ResultsOf the seventeen included studies, eleven reported empirical data and six provided theoretical arguments. There was a large variation in the design of the empirical studies, which were almost exclusively in the context of cognitively normal trial participants, comprising only two prospective cohort studies quantitatively assessing the psychological impact of PET result disclosure which showed a low risk of psychological harm after disclosure. Four studies showed that both professionals and cognitively normal individuals support amyloid PET result disclosure and underlined the need for clear disclosure protocols. From the articles presenting theoretical data, we identified 51 ‘pro’ and ‘contra’ arguments. Theoretical arguments in favor or against disclosure were quite consistent across population groups and settings. Arguments against disclosure focused on the principle of non-maleficence, whereas its psychological impact and predictive value is unknown. Important arguments in favor of amyloid disclosure are the patients right to know (patient autonomy) and that it enables early future decision making.DiscussionBefore amyloid PET result disclosure in individuals without dementia in a research or clinical setting is ready for widespread application, more research is needed about its psychological impact, and its predictive value at an individual level. Finally, communication materials and strategies to support disclosure of amyloid PET results should be further developed and prospectively evaluated.Electronic supplementary materialThe online version of this article (10.1186/s13195-018-0398-3) contains supplementary material, which is available to authorized users.

A randomized controlled trial of amyloid positron emission tomography results disclosure in mild cognitive impairment

“…Although emerging literature suggests that disclosing brain amyloid status to cognitively normal adults and those with subjective cognitive impairment has no discernable effect on psychological well‐being, evidence in overtly symptomatic populations and family caregivers is limited 17 . Consistent with prior investigations of unimpaired persons, 18 we found no significant differences in mood between amyloid positive and negative individuals. However, we observed significant and sustained levels of event‐related distress among MCI care dyads who learned of amyloid positivity, with ratings notably higher than those reported in asymptomatic samples.…”

Added value of amyloid PET in individualized risk predictions for MCI patients

“…A recent review shows that only few studies have addressed potential risks of disclosure to nondemented memory clinic patients [45]. The most important argument against the disclosure of results was theoretical of nature and focused on the principle of “do no harm” [45,46].…”

Cognitively unimpaired adults’ reactions to disclosure of amyloid PET scan results

“…[9][10][11] The extant empirical literature on disclosure of amyloid imaging results to cognitively unimpaired adults is, however, limited. [12,13] The more we understand their understanding of and reactions to biomarker disclosure, the better we can prepare for future clinical practice. [14] Here, we report the results of the Study of Knowledge and Reactions to Amyloid Testing (SOKRATES), a longitudinal qualitative study of cognitively unimpaired adults ages 65 to 85 who learned the result of an amyloid positron emission tomography (PET) scan in order to enroll in a clinical trial.…”