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PET approved by CMS for diagnosing Alzheimer's Disease

CMS has made the following determinations regarding the use of FDG-PET in the diagnosis and treatment of mild cognitive impairment (MCI) and early dementia in elderly patients:

1. The evidence is adequate to conclude that a 2-deoxy-2-[f-18] fluoro-D-glucose Positron Emission Tomography (FDG-PET) scan is reasonable and necessary in patients with documented cognitive decline of at least six months and a recently established diagnosis of dementia who meet diagnostic criteria for both Alzheimer's disease (AD) and Fronto-temporal dementia (FTD), who have been evaluated for specific alternate neurodegenerative diseases or causative factors, and for whom the cause of the clinical symptoms remain uncertain. The following additional conditions must be met:
  • The onset, clinical presentation, or course of cognitive impairment is atypical for AD, and FTD is suspected as an alternative neurodegenerative cause of the cognitive decline. Specifically, symptoms such as social disinhibition, awkwardness, difficulties with language, or loss of executive function are more prominent early in the course of FTD than the memory loss typical of AD.
  • The patient has had a comprehensive clinical evaluation (as defined by he American Academy of Neurology) encompassing a medical history from the patient and a well acquainted informant (including assessment of activities of daily living), physical and mental status examination (including formal documentation of cognitive decline at two time points at least six months apart) aided by cognitive scales or neuropsychological testing, laboratory tests, and structural imaging such as magnetic resonance imaging (MRI) or computed tomography (CT);
  • The patient has been evaluated by a physician experienced in the diagnosis and assessment of dementia;
  • The evaluation did not identify a likely, specific neurodegenerative disease or cause for the clinical symptoms, and information available through FDG-PET is reasonably expected to help clarify the differential diagnosis between FTD and AD;
  • The FDG-PET scan is performed in facilities that have all the accreditation necessary to operate such equipment. The reading of the scan should be done by an expert in nuclear medicine, radiology, neurology, or psychiatry with substantial experience interpreting such scans in the presence of dementia;
  • A brain single photon emission computed tomography (SPECT) or FDG-PET scan has not been obtained for the same indication;
  • The referring and billing providers have documented the appropriate evaluation of the Medicare beneficiary. The referring and billing providers will collect, maintain and furnish upon request to CNS, its agents, or other authorized personnel the following documentation to verify that the conditions for coverage described above have been met:
    • date of onset of symptoms;
    • mini mental status exam (MMSE) or similar test score;
    • report from any neuropsychological testing performed;
    • diagnosis of clinical syndrome (e.g., mild cognitive impairment; dementia);
    • presumptive cause (possible, probable, uncertain AD);
    • results of structural imaging (MRI or CT); s relevant laboratory tests (b12, thyroid hormone);
    • number and name of prescribed medications;
  • In addition, the billing provider must furnish upon request a copy of the FDG-PET scan result for use by CMS and its contractors in Medicare quality assessment and improvement activities.
2. The evidence is not adequate to conclude that FDG-PET is reasonable and necessary for the diagnosis of patients with MCI or early dementia in clinical circumstances other than that specified above absent safeguards that would be present in formal, protocol-driven clinical investigations. Their trials must compare patients who do and do not receive an FDG-PET scan and have as its goal to monitor, evaluate, and improve clinical outcomes, and must meet the following basic criteria:
  • Written protocol on file;
  • Institutional Review Board review and approval;
  • Scientific review and approval by two or more qualified individuals who are not part of the research team;
  • Certification that investigators have not been disqualified.
For purposes of this coverage decision, CMS will determine whether specific clinical trials meet these criteria. CMS will continue to work with the National Institute on Aging, Agency for Healthcare Research and Quality, Alzheimer's Association, device manufacturers, and experts in AD and imaging to develop a large practical clinical trial to address these questions.