Can Amyloid PET Scans Improve Dementia Outcomes?

WASHINGTON — Whether amyloid PET scans can actually improve health outcomes in patients with mild cognitive impairment and dementia remains unknown, but the first randomized controlled clinical trials to assess their use in clinical practice are currently underway.

Preliminary findings from the first prospective multicenter study to examine how PET amyloid imaging with florbetapir influences dementia management and outcomes suggest that health care providers with immediate access to amyloid status from PET scan results make significantly more changes to patient treatment plans than those with delayed access. 

The study involves physicians in France, Italy, and the United States, who were treating 618 patients being diagnosed with mild cognitive impairment (MCI) or dementia, where Alzheimer’s disease was considered a possible cause (<85% certain). 

Overall, 599 and 560 patients, respectively, completed the three-month and one-year follow-up visits. Michael Pontecorvo, PhD, Vice President of Clinical Development for Avid Radiopharmaceuticals, presented the findings at the 2015 Alzheimer’s Association International Conference. 

Treating physicians recorded a working diagnosis and management plan for each patient that included planned diagnostic and neuropsychological testing, follow-up and referral visits, and any medications recommended to improve cognition. 

All patients underwent florbetapir PET scans and were randomly assigned to either immediate or delayed (one year) feedback about their PET amyloid status. 

At the three-month follow-up visit, physicians updated the diagnosis and recorded a summary of actual management. At one year, participants underwent a patient and caregiver outcomes assessment, which measured changes in cognitive status using the Alzheimer’s Disease Assessment Scale-cognitive subscale, health outcomes, resource utilization, mood, function, and quality of life.

Although analyses are currently ongoing, preliminary results indicate a higher proportion of patients in the immediate feedback group had significantly more changes to their baseline management plan compared with those in the delayed feedback group, according to Pontecorvo. 

“This was driven primarily by medication changes, particularly cholinesterase inhibitor use,” he said. 

There were no differences between the two groups on cognitive performance at one year. Medical history, psychotropic drug use, and psychiatric-related events were not significantly different. 

In addition to the current ongoing study, the Alzheimer’s Association and the American College of Radiology have launched a four-year study, called the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS) Study, with funding from the Centers for Medicare and Medicaid.

More than 18,000 Medicare beneficiaries aged 65 years and older will be enrolled at approximately 200 U.S. sites. 

Currently, there are three FDA-approved radiopharmaceutical available to use with PET scans for amyloid imaging, but their use in clinical practice remains controversial. The IDEAS Study is the first time CMS has consented to paying for an amyloid PET scan in a CMS-funded clinical trial to evaluate it’s use as a diagnostic tool for dementia.