**B. Nationally Covered Indications**

  1. **FDG PET Requirements for Coverage in the Differential Diagnosis of AD and FTD**

An FDG PET scan is considered reasonable and necessary in patients with a
recent diagnosis of dementia and documented cognitive decline of at least 6
months, who meet diagnostic criteria for both AD and FTD. These patients have
been evaluated for specific alternate neurodegenerative diseases or other
causative factors, but the cause of the clinical symptoms remains uncertain.

The following additional conditions must be met before an FDG PET scan will be
covered:

    1. The patient's onset, clinical presentation, or course of cognitive impairment is such that 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;

    2. The patient has had a comprehensive clinical evaluation (as defined by the 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 occurring over at least 6 months) aided by cognitive scales or neuropsychological testing, laboratory tests, and structural imaging such as magnetic resonance imaging (MRI) or computed tomography (CT);

    3. The evaluation of the patient has been conducted by a physician experienced in the diagnosis and assessment of dementia;

    4. The evaluation of the patient did not clearly determine a specific neurodegenerative disease or other cause for the clinical symptoms, and information available through FDG PET is reasonably expected to help clarify the diagnosis between FTD and AD and help guide future treatment;

    5. The FDG PET scan is performed in a facility that has all the accreditation necessary to operate nuclear medicine equipment. The reading of the scan should be done by an expert in nuclear medicine, radiology, neurology, or psychiatry, with experience interpreting such scans in the presence of dementia;

    6. A brain single photon emission computed tomography (SPECT) or FDG PET scan has not been obtained for the same indication. (The indication can be considered to be different in patients who exhibit important changes in scope or severity of cognitive decline, and meet all other qualifying criteria listed above and below (including the judgment that the likely diagnosis remains uncertain.) The results of a prior SPECT or FDG PET scan must have been inconclusive or, in the case of SPECT, difficult to interpret due to immature or inadequate technology. In these instances, an FDG PET scan may be covered after one year has passed from the time the first SPECT or FDG PET scan was performed.)

    7. The referring and billing provider(s) have documented the appropriate evaluation of the Medicare beneficiary. Providers should establish the medical necessity of an FDG PET scan by ensuring that the following information has been collected and is maintained in the beneficiary medical record:  

      * Date of onset of symptoms;
      * Diagnosis of clinical syndrome (normal aging; mild cognitive impairment (MCI); mild, moderate or severe dementia);
      * Mini mental status exam (MMSE) or similar test score;
      * Presumptive cause (possible, probable, uncertain AD);
      * Any neuropsychological testing performed;
      * Results of any structural imaging (MRI or CT) performed;
      * Relevant laboratory tests (B12, thyroid hormone); and,
      * Number and name of prescribed medications.

The billing provider must furnish a copy of the FDG PET scan result for use by
CMS and its Medicare Administrative Contractors upon request. These
verification requirements are consistent with Federal requirements set forth
in 42 Code of Federal Regulations, section 410.32 generally for diagnostic
x-ray tests, diagnostic laboratory tests, and other tests. In summary, section
410.32 requires the billing physician and the referring physician to maintain
information in the medical record of each patient to demonstrate medical
necessity [410.32(d) (2)] and submit the information demonstrating medical
necessity to CMS and/or its agents upon request [410.32(d)(3)(I)] (OMB number
0938-0685).

  2. **FDG PET Requirements for Coverage in the Context of a CMS-approved Practical Clinical Trial Utilizing a Specific Protocol to Demonstrate the Utility of FDG PET in the Diagnosis, and Treatment of Neurodegenerative Dementing Diseases**

An FDG PET scan is considered reasonable and necessary in patients with MCI or
early dementia (in clinical circumstances other than those specified in
subparagraph 1) only in the context of an approved clinical trial that
contains patient safeguards and protections to ensure proper administration,
use and evaluation of the FDG PET scan.

The clinical trial 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.
In addition, it must meet the following basic criteria:

    1. Written protocol on file;
    2. Institutional Review Board review and approval;
    3. Scientific review and approval by two or more qualified individuals who are not part of the research team; and,
    4. Certification that investigators have not been disqualified.

**C. Nationally Non- Covered Indications**

All other uses of FDG PET for patients with a presumptive diagnosis of
dementia-causing neurodegenerative disease (e.g., possible or probable AD,
clinically typical FTD, dementia of Lewy bodies, or Creutzfeld-Jacob disease)
for which CMS has not specifically indicated coverage continue to be
noncovered.

**D. Other**

Not applicable.

**(This NCD last reviewed September 2004.)**