How to Order an Amyloid PET Scan
Amyloid PET scans must be ordered by a dementia expert (neurologist, psychiatrist, or geriatrician who devotes ≥25% of clinical time to cognitive disorders) after completing a comprehensive diagnostic workup that demonstrates diagnostic uncertainty despite standard evaluation. 1, 2
Who Can Order the Scan
You must be a dementia expert defined as:
- Board-certified in neurology, psychiatry, or geriatric medicine
- Devotes at least 25% of patient contact time to evaluating and managing adults with cognitive impairment or dementia
- Has peer recognition in this area 1
Primary care providers should not order amyloid PET scans directly—these patients should be referred to a dementia expert first. 1
Required Pre-Scan Documentation
Before ordering, you must complete and document ALL of the following in the medical record 1:
Clinical Information
- Age and date of symptom onset
- Identification of clinical syndrome (MCI vs. dementia)
- Evidence of persistent or progressive cognitive decline
- Objective cognitive assessment (MMSE, MoCA, or similar standardized test)
Completed Workup
- List of all medications (especially psychoactive drugs and rationale)
- Results of neuropsychological testing
- Structural brain imaging (MRI or CT already performed)
- Laboratory tests: CBC, chemistry profile, vitamin B12, thyroid function
- Known comorbidities documented
Critical Justification
- Specific reasons why diagnosis remains uncertain after completing the above workup and treating comorbidities
- Treatment and care plan that will change based on amyloid PET results
Appropriate Clinical Scenarios
Order amyloid PET ONLY in these situations 2, 3:
Appropriate Use
- Progressive unexplained MCI where etiology remains uncertain
- Possible AD with atypical features (unclear presentation, atypical course, or mixed etiology)
- Early-onset dementia (age <65 years) where AD is suspected
- Diagnostic uncertainty persists after complete evaluation and knowledge of amyloid status will change management
Inappropriate Use (Do NOT Order)
- Probable AD with typical age of onset and typical presentation
- Unconfirmed cognitive complaints without objective impairment
- Asymptomatic individuals (screening purposes, family history alone, genetic testing)
- To judge dementia severity
- When results will not change management 2
How to Actually Place the Order
- Complete the documentation checklist above in the patient's medical record
- Contact your institution's nuclear medicine/PET department directly
- Specify one of the FDA-approved tracers: F-18 florbetapir, F-18 flutemetamol, or F-18 florbetaben 2
- Share the documented checklist with the PET physician
- Be prepared to submit documentation to insurance for medical necessity 1
Coverage Considerations
- Medicare covers amyloid PET through the Coverage with Evidence Development (CED) program 2
- Documentation must demonstrate medical necessity—the checklist above serves this purpose 1
- Most scans ordered by dementia experts (98%) meet appropriate use criteria when properly documented 4
Common Pitfalls to Avoid
Do not order if:
- You haven't completed structural imaging first (MRI or CT must be done) 2, 1
- Basic labs haven't been checked (B12, thyroid, CBC, chemistry)
- You cannot articulate how the result will change management
- The patient has typical AD presentation—amyloid PET adds little value here 2
Remember: A positive amyloid PET indicates amyloid pathology but doesn't confirm clinical AD (can be positive in cognitively normal elderly), and a negative scan means low probability of AD but doesn't rule out other neurodegenerative diseases. 2 The scan must be integrated with comprehensive clinical data—it is not a standalone diagnostic test. 1
Recent update (2024): The newest appropriate use criteria from SNMMI now explicitly include patients with equivocal or inconclusive CSF biomarkers as appropriate candidates for amyloid PET. 3 Additionally, amyloid PET is now required to confirm amyloid pathology before initiating disease-modifying therapies for AD. 5