SNMMI commends the U.S. Food and Drug Administration (FDA) for recognizing the critical role of nuclear medicine in Alzheimer’s and dementia imaging and therapy.
On June 23, 2025, the FDA approved an expanded indication for three amyloid imaging agents. These agents are already in use to visualize amyloid plaques in patients with cognitive decline in suspected Alzheimer’s Disease, but the newly expanded labels modernize their role in diagnosis and treatment of Alzheimer’s Disease. The new indications include a quantitative measurement of amyloid plaque and use for therapy monitoring.
Florbetapir F-18, flutemetamol F-18, and florbetaben F-18 PET agents have been used for a decade to assess for the presence and density of amyloid plaques in the brain. With the approval and clinical use of anti-amyloid therapies such as aducanumab, lecanemab, and donanemab, the PET tracers are needed to monitor the response to therapy. Quantitative assessment of amyloid scans will allow for more precise measurements, as opposed to the qualitative read. Amyloid PET scans can be used to determine when anti-amyloid therapies can be discontinued. SNMMI has played a central role in advancing quantification methods for molecular brain imaging and in our advocacy to the FDA for the recognition of the critical importance of quantification.
Under the expanded labels, the agents can also be used to predict cognitive decline. According to diagnostic criteria from the Alzheimer’s Association, an abnormal or positive amyloid PET scan is now sufficient to support a diagnosis of Alzheimer’s Disease, as amyloid-positive scans are now associated with increased risk of progression from mild cognitive decline to Alzheimer’s Disease.
While the expanded use of these tracers indicates an increasingly important role for nuclear medicine, several roadblocks remain. Although amyloid plaques have been identified as an Alzheimer’s biomarker, they have not been identified as the sole cause of the disease.
The high cost of these agents also limits patient access, making the appropriate selection of patients a key consideration. There is no evidence of the efficacy of amyloid-targeting therapy in patients with advanced cognitive decline.
Still, the FDA’s decision reflects a new era in diagnosing and treating Alzheimer’s Disease. By recognizing biomarkers such as amyloid plaques, the field is moving from treating symptoms to treating pathology—a huge step forward in our goal for better patient outcomes.