MEDCAC Meeting

Positron Emission Tomography (FDG) for Alzheimer's Disease/Dementia (Diagnostic Imaging Panel)


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Positron emission tomography (PET) is a non-invasive imaging procedure used for measuring the concentrations of positron-emitting radioisotopes within the tissue of living subjects. 2-[F18] fluoro-2-deoxy-D-glucose (FDG) is a radiopharmaceutical that is attracted to higher areas of metabolism. On December 15, 2001, CMS published a Decision Memorandum on a request for broad coverage (CAG-00065) of all oncological indications, heart disease, and neurological disorders. The December 15th decision memorandum stated that CMS had insufficient evidence to support coverage for the indication of Alzheimer's disease/dementia at that time but would refer the issue to MCAC.

Actions Taken


Minutes of January 10, 2002 Meeting


Baltimore Convention Center
Baltimore, Maryland


Frank J. Papatheofanis, M.D.

Barbara J. McNeil, M.D.

Janet Anderson
Executive Secretary

Voting Members
Carole R. Flamm, M.D.
Jeffrey C. Lerner, Ph.D.
Steven Guyton, M.D.
Kim J. Burcheil, M.D.

Consumer Representative
Sally Hart, J.D.

Marilyn Albert, Ph.D.
Keith Johnson, M.D.
Peter Neumann, Sc.D.

CMS Representative
Sean R. Tunis, M.D.

Thursday, January 10, 2002, 8:35 a.m.

The Diagnostic Imaging Panel met on January 10, 2002, to discuss the use of PET in the diagnosis and management of Alzheimer's Disease. The meeting began with a reading of the conflict of interest statement, and the call to order.

Lobbying of Panel Members. Sean Tunis, M.D. mentioned reports that advocates and stakeholders approached several members of various Medicare Coverage Advisory Committee (MCAC) panels concerning topics being addressed by the MCAC. Dr. Tunis stated that since MCAC committee and panel meetings are designed to be public, and non public conversations between members and advocates or stakeholders is therefore discouraged. At the same time, Dr. Tunis noted that panel members are special government employees only during the time panels are meeting and that members are free to engage in discussion with whomever they choose on their own time, and not as a representative of the MCAC. Dr. Tunis stated that beginning with the next MCAC panel, panelists would be asked to reveal, in addition to the current conflict of interest information, whether they had been approached by any advocate or stakeholder concerning the matters to be discussed.

Charge to Panel. The chairman, Frank Papatheofanis, M.D., presented the charge to the panel, stating that the panel would closely follow the published agenda. In the course of the presentations to follow, Dr. Papatheofanis encouraged panelists to think about the general discussion questions and the voting question presented by the Centers for Medicare & Medicaid Services (CMS) representative.

CMS Presentation of Request. A CMS representative presented the panel with the history of the request for coverage, the general discussion questions and the voting question as set forth in the panel's information packet.

Summary of AHRQ Presentation to June 19, 2001 MCAC Executive Committee. Deborah Zarin, M.D. offered the panel a summary of the June 14, 2001 presentation to the MCAC Executive Committee as well as an overview of the technology assessment decision model, and some definitions that the panel should use in evaluating the assessment.

Presentation of Technology Assessment. David Matchar, M.D. presented a summary of the Technology Assessment (TA), which came to the following conclusions.

For patients who had had the American Academy of Neurology (AAN) recommended clinical evaluation, treatment without further testing is superior to treatment based on clinical evaluation with the addition of a PET scan. Treating all patients without performing a PET scan would result in all AD patients getting treatment and therefore those with a false positive clinical diagnosis getting unnecessary treatment. Adding a PET scan would decrease the unnecessary treatments by about 10 percentage points, but also decrease treatment of the number of patients who actually have the disease by about 10 percentage points, since the sensitivity of PET is 90%. The TA concluded that because treatment is relatively benign, treatment based on the clinical evaluation only is superior since the increase in true negatives with the use of PET is overshadowed by the concomitant decrease in true positives.

For patients with Mild Cognitive Impairment (MCI), if the evidence for treatment efficacy of cholinesterase inhibitors in patients with dementia can be extrapolated to this population, then empiric treatment would also be superior to treating based on PET scan results.

If the evidence for treatment efficacy can be extrapolated to patients who are currently asymptomatic, but have an elevated risk of having AD by virtue of a first degree relative, then empiric treatment would be superior to treating based on PET scan results. The TA acknowledged PET scanning could be of value if a new treatment was developed that was more effective but had an increase in risk associated to treatment.

Dr. Matchar further commented that there may be other benefits to testing that are not engendered by this analysis, namely that testing may conceivably improve patient end of life planning, decision making about reproduction in a young individual who has a first degree relative with AD, or more compliance with a drug treatment regimen, although none of these scenarios are supported by clinical evidence. He concluded the presentation with possible reasons for not testing, including the suggestion that people who are asymptomatic who are labeled as having disease may have significant reduction in their quality of life, possibly leading to depression, in addition to the negative connotation associated with the diagnosis that may interfere with employment and insurability. Dr. Matchar answered questions from the panel following his presentation.

Scheduled Public Comments. The panel heard from three scheduled speakers, Daniel Silverman, M.D.; Gary Small, M.D.; and Peter Conti, M.D.

Dr. Silverman presented study summaries showing the sensitivity and specificity of PET in diagnosing neurodegenerative disease in general, and AD specifically. He also presented information showing PET's ability to predict long-term progression of symptoms. He then compared a subset of the UCLA results to the results obtained in the technology assessment. Following his presentation, he answered questions from panel members.

Dr. Small spoke to the panel augmenting some of Dr. Silverman's comments from a clinical perspective. Following his presentation, he answered questions from panel members.

Dr. Conti spoke as a representative of the Society of Nuclear Medicine. He expressed the Society's strong support for the addition of Alzheimer's disease as a CMS reimbursable indication for FDG PET scanning.

Open Public Comments. Gary Small, M.D. made further comments to the panel.

Open Panel Discussion. The chairperson facilitated the panel discussions by suggesting the panel members offer their individual opinions concerning the three discussion questions posed by CMS. The guest experts on the panel contributed their thoughts during this phase as well. It was also opined that the charge of MCAC panels is only to make evidence based recommendations to the MCAC Executive Committee (EC). The panel asked that a suggestion be forwarded to CMS to enlist the assistance of experts to form an ad hoc committee for further assessment of decision modeling to be used in the future.

The guest experts opined that there are currently no data regarding use of PET as a replacement for rather than as an adjunct to conventional testing. Following the panelists' comments on each discussion question, Dr. Matchar, Dr. Zarin, Dr. Small, Dr. Silverman and Dr. Conti were afforded an opportunity to make final comments to the panel.

Final Panel Recommendations.

A motion was made and seconded to vote on the following question: Is the evidence adequate to demonstrate that PET has clinical benefit in evaluating patients with suspected AD? Following discussion wherein CMS representatives clarified that the question as posed would apply to patients with probable Alzheimer's, and potentially could include symptoms, mild symptoms, but would not include the asymptomatic population, the motion to vote on that question was withdrawn.

A motion was made and seconded to vote on the following question: Is the evidence adequate to demonstrate that PET has clinical benefit in evaluating patients with possible or probable AD as defined by the current AAN guidelines? To this question, the panel voted unanimously in the negative.

Following a request from Dr. Tunis to address MCI, a motion was made and seconded to vote on the following question: Is the evidence adequate to demonstrate that PET has clinical benefit in evaluating patients with mild cognitive disorder (MCI) as defined by the current AAN guidelines? To this question, the Panel voted unanimously in the negative.

Closing Remarks. Dr. Tunis informed the panelists and public that in all likelihood, the EC will act upon the recommendations of this panel, since the regulatory change to implement BIPA has not yet taken effect.

Adjournment. The meeting adjourned at 2:20 p.m.

I certify that I attended the meeting
of the Diagnostic Imaging Panel
on January 10, 2002, and that these minutes
accurately reflect what transpired.
Janet Anderson
Executive Secretary

I approve the minutes of this meeting
as recorded in this summary.
Frank J. Papatheofanis, MD, PhD, MPH

Panel Voting Questions

Contact Information

Other Material

Associated Technology Assessment