PET imaging is transforming Alzheimer's disease management by helping doctors select patients for anti-amyloid therapies like lecanemab and donanemab, monitor treatment response, and make personalized care decisions based on amyloid and tau biomarkers.
- Amyloid PET now guides patient selection for anti-amyloid therapies and helps determine when treatment can be discontinued based on amyloid burden reduction.
- Tau PET provides prognostic information and predicts which patients will benefit most from treatment, enabling more personalized therapy decisions.
- Precision medicine approaches using amyloid and tau PET are already being implemented at tertiary centers across Europe to improve individual patient outcomes.
- Major barriers to wider implementation include lack of reimbursement and limited PET tracer availability, restricting access to patients across Europe.
- Neuroinflammation PET offers valuable research insights but remains primarily a research tool, not yet ready for routine clinical decision-making in Alzheimer's care.
Anti-amyloid therapies such as lecanemab and donanemab are changing what clinicians ask of molecular imaging in Alzheimer’s disease. PET is now being considered for more than confirming amyloid pathology. It may also help guide treatment, track response, and identify who is likely to benefit.
These topics came up at the European Association of Nuclear Medicine (EANM) 2026 congress in Vienna, in a session on assessing, staging, and monitoring Alzheimer’s in the era of disease-modifying therapies.
Dr. Matthias Brendel, deputy director of the Department of Nuclear Medicine at LMU University Hospital Munich, Germany, spoke about where PET stands and what is holding it back.
AuntMinnieEurope: With disease-modifying Alzheimer's therapies entering clinical practice, how is the role of PET biomarkers in patient selection and monitoring changing?
Brendel: PET is increasingly being used to assess amyloid status, which is essential for determining eligibility for anti-amyloid therapies. Beyond patient selection, amyloid PET is also becoming relevant for treatment monitoring, as therapy may be discontinued once amyloid burden falls below a certain threshold.
It is encouraging to see that PET is being used in clinical practice despite the lack of reimbursement in some settings. Several cohorts presented at EANM included patients who were paying for both their treatment and imaging themselves.
Alongside amyloid PET, tau PET is increasingly recognized as a prognostic biomarker. Importantly, it can also help predict the clinical benefit patients may derive from treatment.
AME: Which developments in molecular neuroimaging do you expect to have the greatest impact on patient care?
Brendel: Tau PET will likely become increasingly important in determining eligibility for anti-amyloid treatment.
By assessing tau pathology, we can better judge whether a particular therapy has sufficient potential to benefit an individual patient. This could represent an important step toward more personalized treatment decisions.
AME: How much additional value does tau PET provide over amyloid PET and blood biomarkers when selecting patients for lecanemab or donanemab?
Brendel: Tau PET is an excellent tool for disease staging and provides valuable information about the potential efficacy of treatment.
While amyloid PET establishes the presence of amyloid pathology, tau PET provides additional prognostic information that can help assess the likelihood of clinical benefit from anti-amyloid therapies.
AME: How close is neuroinflammation PET to becoming a clinically useful tool for diagnosis or treatment monitoring?
Brendel: Neuroinflammation PET is highly valuable for understanding the mechanisms underlying disease progression.
However, its use in routine Alzheimer's disease care remains some way off. The main challenges include insufficient harmonization between tracers and the variety of molecular targets being investigated.
For now, neuroinflammation PET remains primarily a research tool rather than an established biomarker for routine clinical decision-making.
AME: How are these advances changing the management of individual patients with Alzheimer's disease?
Brendel: Amyloid and tau PET are already being implemented at several tertiary centers.
These precision medicine approaches allow us to better guide treatment decisions and monitor therapies based on individual disease characteristics. Molecular imaging is therefore becoming an increasingly important component of personalized Alzheimer's care.
AME: Could PET eventually help determine when a patient should stop or change treatment?
Brendel: Amyloid PET can already provide information to support decisions about treatment discontinuation once amyloid burden has fallen below a defined threshold.
However, we still need more evidence to understand whether stopping treatment earlier has an impact on long-term clinical outcomes.
Another important area for future research is the development of alternative treatment strategies, including switching between different antibodies. It remains to be seen whether such approaches could further improve long-term outcomes.
AME: What are the biggest barriers to making amyloid and tau PET routinely available to Alzheimer's patients across Europe?
Brendel: The two major barriers are the lack of reimbursement and limited availability of PET tracers.
Although the clinical importance of molecular imaging is becoming increasingly evident, these practical challenges continue to restrict broader implementation.
Overcoming them will be essential to making PET-guided precision medicine more widely accessible to patients with Alzheimer's disease.
Our full coverage of EANM 2026 can be found here.
