Patient Requests for Off-Label Bioprediction of Dementia

In 2012, the FDA approved for the differential diagnosis of Alzheimer's disease a brain-imaging technology, Amyvid-PET (aka florbetapir-PET), capable of non-invasively estimating the burden of amyloid plaques; this approval for one indication renders the technology a candidate for off-label use for another indication according to a physician's judgment. What should a physician do if an educated, pro-active, and concerned patient requests off-label use of Amyvid-PET to help her estimate the likelihood that her mild memory complaints are "just normal aging" or are likely to profoundly worsen? I consider reasons that a physician might justify denial of such a request, including concerns of safety, uncertain benefit, and fair resource allocation, but cautiously conclude that there may be certain cases where off-label bioprediction would be permissible.