Use of PET Changes Clinical Diagnosis for Some Patients with Dementia

Positron emission tomography (PET) with [18 F]flutemetamol resulted in changes in the diagnostic process work-up of patients with early onset dementia, according to a study presented at the Alzheimer’s Association International Conference 2014 (AAIC).

Researchers from the Netherlands and the United States undertook a study to examine the diagnostic value of [18F]flutemetamol PET in assessing patients with early onset dementia. “Early and accurate diagnoses may have implications for both prognosis and treatment among patients with early onset dementia,” lead investigator Marissa Zwan, MD, said in a release. “Greater diagnostic confidence supports better patient management and helps physicians to determine appropriate treatment options, as well as helping patients and caregivers to plan for the future.”

Eighty patients with early onset dementia (before age 70) participated in the study and underwent an [18F]flutemetamol PET scan, which was visually assessed as amyloid positive or negative. Physician confidence in the diagnosis based on routine diagnostic work-up for dementia was 90 percent.

The results showed that 48 of 63 patients (76 percent) who had been diagnosed with Alzheimer’s disease (AD) prior to the imaging were [18 F]flutemetamol positive. Four out of 17 patients (24 percent) diagnosed with other dementias were also [18 F]flutemetamol positive.

“Access to PET results led to a change in diagnosis in 16 (20 percent) patients,” the authors noted. “In 11 out of 13 patients, a negative PET scan caused a change of the initial AD diagnosis to another dementia. In three out of four other dementia patients, the initial diagnosis was changed to AD after receiving a positive PET scan.”

Twenty-seven patients (34 percent), who had an initial clinical diagnosis of Alzheimer’s disease had a change in their healthcare management following the PET results. Thirteen patients underwent additional ancillary investigations after access to the PET scan results. 

The authors concluded that PET resulted in changes in clinical diagnosis of some patients with early-onset dementia and, in turn, in their management.