Study confirms benefits of early PET scanning in Alzheimer’s patients

Patients with symptoms of Alzheimer’s disease (AD) who are diagnosed early with PET imaging receive medication earlier and have better clinical outcomes, according to interim results from the first study to confirm the benefits of early diagnosis in the neurodegenerative disease.

These early findings from the Metabolic Cerebral Imaging in Incipient Dementia study come less than a week before an expected national Medicare coverage decision on PET scans for patients with signs of cognitive decline. The Centers for Medicare & Medicaid Services (CMS) sponsored the trial, and interim results are being presented Sept. 26 at the Medical Biotech Forum in China.

Overall, Medicare approved the enrollment of 710 volunteers for the multicenter, prospective study, though the initial findings are based on an examination of 63 patients. All patients underwent FDG-PET and neuropsychological testing at baseline, which was repeated every six months for two years. One arm of the study featured patients whose doctors viewed the PET scans, while the other arm included patients whose doctors were randomized to not have access to the scans.

Results showed that approximately 40 percent of the patients whose doctors saw evidence of AD on the scan were given drugs to treat dementia within the first six months of the study. None of the patients with similar evidence of AD in the group where doctors didn’t have scan access received medication within six months, and only 12 percent were prescribed drugs within a year.

The patients who had early treatment fared better over the subsequent two years than those who did not, reported Daniel Silverman, MD, PhD, of the University of California, Los Angeles, the study’s principal investigator. “During the subsequent two years after their PET scans, these patients had superior executive function, better memory abilities and greater preservation of overall cognitive function," Silverman said in a press release.

He added that early treatment could reduce overall healthcare spending, since misdiagnosed patients may be prescribed drugs with no benefit and those who are properly treated may be able to delay intensive, expensive care in a nursing home setting.

Currently, Medicare does not offer reimbursement for PET scans of patients who show signs of cognitive decline but do not yet have dementia. However, CMS is re-evaluating policies and a national coverage decision on amyloid imaging PET scans is expected Oct. 1, according to Silverman.