The Alzheimer’s Association and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) have released updated Appropriate Use Criteria (AUC) for amyloid and tau PET imaging, according to a statement from the Alzheimer’s Association.1
The report, published simultaneously in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association and The Journal of Nuclear Medicine, provides critical guidance for primary care clinicians, neurologists and other clinicians who assess and manage individuals with cognitive impairment on the most appropriate use of the “gold standard imaging tests,” the association stated.
“The field of dementia diagnosis and treatment is evolving rapidly, and this report incorporates the latest data and technological advances in recommending the best use of amyloid and tau PET. These imaging tests can also be compared to other emerging technologies, such as blood tests,” coauthor of AUC report Maria C. Carrillo, PhD, said. Carrillo, who is Alzheimer’s Association chief science officer and medical affairs lead, continued, “Neurologists and other clinicians rely on amyloid and tau PET, and it’s important they have the most up-to-date information on when they should be used.”1
This update is the first revision since the initial AUC for amyloid PET was introduced in 2013.
The revised AUC include 17 real-world scenarios in which amyloid or tau PET may be considered, with each test evaluated separately and rated for suitability for each scenario.
Overall, the strongest evidence for their use includes:
In most cases, these tests should not be used for:
These tests, AUC authors stress, should only be ordered when the results will directly impact patient care, for example, informing safety measures like driving or independent living. The criteria aim to reduce unnecessary testing and ensure that these tools are used appropriately as part of a broader diagnostic process.
“Amyloid and tau PET can support and enable earlier and more accurate diagnosis, which is essential to high quality care and treatment for dementia, providing appropriate support services and future planning," lead author Gil D Rabinovici, MD, said in the statement. The imaging tests are not meant to be used as the sole guide to assessment or treatment, Gil added. Clinicians of course must consider the person’s cognitive status and age, and work with both the patient and family members to even decide if the tests will be useful. Gil, the Edward and Pearl Fein Distinguished Professor in memory and aging at the University of California San Francisco emphasized that based on the collective experience of the AUC developers, “the AUC should be considered guidelines for clinicians, not a substitute for careful clinical judgment that considers the full clinical context for each patient with cognitive complaints.”1
The new criteria prioritize optimizing patient care, Kevin Donohoe, MD, chair of SNMMI’s Committee on Guidance Document Oversight, pointed out. The AUC also discuss the use of PET imaging for determining eligibility for newly introduced disease-modifying Alzheimer's treatments and for following treated patients for response to therapy. It is expected these AUC will reduce the need for less specific diagnostic testing and provide guidance for safety considerations.”
Currently, there are 3 amyloid PET tracers approved by the FDA for detecting amyloid plaques in the brain. For tau PET imaging, the newer technique, the first tau tracer used to identify tau tangles, was approved in 2020. These tools allow for earlier and more precise diagnoses, which are critical for identifying candidates for disease-modifying therapies that target early stages of Alzheimer’s.1
"Amyloid and tau PET are part of an expanding field of Alzheimer’s biomarkers, including CSF and blood-based biomarkers. Future research and development of clinical practice guidelines will determine the specific role of PET within the larger landscape of these emerging biomarkers in diagnostic frameworks," wrote authors of the AUC report.2
In this rapidly evolving field, the report reflects the latest evidence and technological advances, which are the standard against which new technology is measured, the Alzheimer’s Association statement concluded.1
