Physicians tailor Alzheimer’s diagnoses, treatments after viewing amyloid PET scans

The first randomized, controlled study to determine whether physicians change their clinical decision-making after considering images of accumulated amyloid plaques in patients with suspected Alzheimer’s disease has come out with affirmative findings.

In the study, knowledge of amyloid status as revealed by PET following injection with the radiopharmaceutical florbetapir led to both adjusted diagnoses and modified disease management.

The findings were presented July 22 at the Alzheimer’s Association International Conference 2015 (AAIC) in Washington, D.C., by Michael Pontecorvo, PhD, of Avid Radiopharmaceuticals and colleagues. Avid, a subsidiary of Eli Lilly, markets a florbetapir injectable called Amyvid.

The study looked at physicians in France, Italy and the U.S. treating 618 patients for possible Alzheimer’s following initial diagnoses of mild cognitive impairment or dementia, according to a news release from AAIC. The doctors recorded a working diagnosis and a management plan before sending the patients for a florbetapir PET scan.

Physicians were then randomly placed into one of two groups. An “immediate feedback” group received results from the scan at a 3-month visit. A “delayed feedback” group did not get the scan results until one year after the initial diagnosis.

“Changes in patient management were greater in the group who received immediate amyloid PET scan results than among those who were delayed for one year,” Pontecorvo said in the release. “This was driven primarily by medication changes, particularly cholinesterase inhibitor use.”

The Alzheimer's Association noted the appropriate role of amyloid PET scans in clinical practice in the U.S. has been controversial and remains so. Despite FDA approval of florebetapir as a diagnostic tool for Alzheimer’s, CMS is not yet convinced that PET amyloid imaging improves outcomes and has only agreed to pay for it in trials it sanctions under its Coverage with Evidence Development program.

In light of the new data, Pontecorvo is sanguine about the prospects for broad clinical adoption.

“Alzheimer’s disease is one of many possible causes of cognitive impairment, which can make diagnosis challenging,” he commented in a release from Lilly that provides additional study details. “These findings provide further support for how knowledge of the presence or absence of amyloid pathology may affect both diagnosis and management in patients being evaluated for Alzheimer's disease or other possible causes of cognitive decline.”