Molecular Cerebral Imaging in Incipient Dementia (MCI-ID) II

Overview

A substantial portion of people covered by Medicare will develop Alzheimer's disease and other forms of dementia that together devastate the lives of millions of people in the United States, and cost us a total of over $200 billion every year. Getting a brain scan with a PET scanner to look for abnormal brain metabolism patterns is recognized as "reasonable and necessary" for some patients with "a recently established diagnosis of dementia" (Centers for Medicare and Medicaid Services (CMS), Decision Memo CAG-00088R), but the evidence is considered less clear for patients having less severe cognitive problems, and/or for patients getting a brain scan with a PET scanner to look for abnormal proteins in the brain (CMS Decision Memo CAG-00431N). This project employs a scientifically rigorous design (prospective, multi-centered, randomized controlled trial) to determine whether such PET scanning can help distinguish more accurately than is being done in current clinical practice those patients with early molecular changes in their brains who will benefit from Alzheimer related treatments from those patients who will not, as proven by measuring to what extent the PET scans actually lead to earlier appropriate therapy, and in fact result in improved outcomes for Medicare beneficiaries and for the health care system in which they obtain care.

The overarching objective of this project is to test whether diagnostic assessments informed by data on molecular cerebral changes can lead to improved health outcomes of an epidemiologically major segment of the geriatric patient population - people experiencing changes in their cognitive skills relative to their prior level of cerebral functioning. In the present proposal, we specifically aim to measure how knowledge of molecular cerebral information 1) influences the therapeutic management of patients being evaluated for symptoms of cognitive decline, and 2) impacts upon long-term health outcomes, particularly for patients having findings on positron emission tomography (PET) scans consistent with presence of Alzheimer's disease (AD)- like changes in their brains. Patients suffering from documentable decline of cognitive function will undergo baseline neuropsychologic testing, and neuroimaging with MRI and PET. Reports of PET scans will be sealed at the time of interpretation, and then randomized with respect to whether they are released to the patients' managing physicians at the time of interpretation, or two years after the time that scanning is performed. All treatment decisions will be made by the managing physicians and their patients. Cognitive abilities, functional status, and other clinical and social history parameters will be assessed every six months. Our central hypothesis is that among the group of patients whose PET scan results are conveyed to their physicians at the time of scanning, cognitive and functional abilities will be maintained at a higher level during the two years following PET. Beyond addressing the specific aims noted above and further described below, a valuable feature of this project will be the collection of a rich source of data that can be used to address many questions beyond its major focus (e.g., diagnostic value of volumetric MRI data used instead of, or in conjunction with, PET data in the Medicare beneficiary population; incremental value of applying statistically parameterizing and/or quantifying software tools to PET data). The protocol has been designed to conform to all standards specified by the Centers for Medicare and Medicaid Services (CMS) for Coverage with Evidence Development (CED), generally, and with all requirements for a CED study responsive to CMS Decision Memo CAG-00431N, specifically.