Neuroimaging Fuels Advances in Alzheimer’s Disease Diagnosis, Treatment

AD represents a significant societal burden that is increasing in prevalence as the population ages. The number of people affected by it in the United States alone is expected to rise from 7 million today to nearly 13 million by 2050.

“Fortunately, there is a light at the end of the tunnel because there have been new disease-modifying therapies successfully implemented just recently,” said Alexander Drzezga, MD, director of the Department of Nuclear Medicine at the University Hospital of Cologne in Germany. “The idea of these therapies is that they attack the amyloid aggregates in the brain, a hallmark of Alzheimer’s disease.” 

Dr. Drzezga outlined numerous reasons for optimism during his plenary address, Remembering Tomorrow: A Bright Future in Imaging and Treating Neurodegeneration at the Arie Crown Theater Tuesday. Foremost among the reasons is the development of new biomarkers that show amyloid plaques and tau fibrillary tangles on PET scans.

“In a way, the tau PET is like a combination of FDG PET and amyloid PET because it gives information on the type of pathology and the location of it, which is a huge advantage,” Dr. Drzezga said. “If you combine amyloid plus tau PET information, you may even predict who of the cognitively healthy subjects will convert to some cognitive decline in the relatively near future.” 

New Tools Speed AD Diagnosis and Trials

Advances in disease staging disease, like the Centiloid scale, are helping to improve clinical trials. Developed in 2015, the scale takes tracer uptake in the brain and translates it into a sort of a temperature scale between 0 and 100, where 0 is the mean value of young healthy controls and 100 is the mean value in patients with full-blown disease. 

“The consensus today is that values above 30 Centiloid would be sufficient to define relevant amyloid plaque pathology in the brain, so these patients would be suitable for inclusion in therapy trials,” said Dr. Drzezga. “Values below 10 would reliably exclude amyloid pathology in the brain.” 

In a recent drug trial, patients saw a decline in their amyloid levels of about 80 Centiloids, indicating that the amyloid was essentially removed from the brain. 

“If you consider therapies, we are looking into a bright future, because the number of drugs studied is ever increasing,” Dr. Drzezga said. “The pipeline is really developing, and this is also associated with a huge number of scans required, so the capacities for imaging are also quite high.” 

Fluid biomarkers, instrumentation advances and AI tools are also driving advances in diagnosis and treatment, Dr. Drzezga said. These technological advances are occurring in parallel with our growing knowledge of the protective effects of exercise, diet and education on the brain. 

“Education seems to be protecting against the development of symptoms in subjects even if they developed the underlying pathology,” Dr. Drzezga said. “As the RSNA annual meeting is obviously a highly educational event, I would like to suggest that attending it may even mitigate the risk for cognitive decline in the future.”

Access the plenary session, “Remembering Tomorrow: A Bright Future in Imaging and Treating Neurodegeneration,” (T6-PL06) on demand at RSNA.org/MeetingCentral