Leveraging PET Biomarkers for Alzheimer Diagnosis in Real-World Scenarios: Phillip Kuo, MD, PhD, FACR

WATCH TIME: 10 minutes

"While amyloid PET scans across these cases appear similarly saturated, tau PET adds critical information about disease stage and severity."

Since the initial appropriate use criteria (AUC) for amyloid positron emission tomography (PET) were introduced in 2013, an updated set of guidelines was recently published by a multidisciplinary workgroup. Featured in Alzheimer’s & Dementia and the Journal of Nuclear Medicine, the revised recommendations aim to guide clinicians on when amyloid and tau PET imaging can be most effective for diagnosing and managing cognitive decline. The guidelines also identified situations where PET scans would be unlikely to provide meaningful clinical value.^1,2

The updated AUC underscored the most robust evidence for using amyloid and tau PET imaging in specific scenarios, such as assessing mild cognitive impairment, resolving diagnostic uncertainty in dementia, and determining eligibility for emerging treatments or monitoring their effectiveness. However, the guidance advised against using these tests in individuals without cognitive impairment, including those carrying the APOE4 gene associated with Alzheimer disease (AD) risk. Additionally, PET imaging was discouraged for nonclinical purposes, such as legal disputes, insurance claims, or employment screenings, and it should not replace genetic testing in cases of suspected hereditary conditions.³

Building on these updated criteria, coauthor Phillip Kuo, MD, PhD, FACR, a professor in the department of diagnostic radiology at City of Hope, shared insights on the evolving role of PET biomarkers in clinical practice during a recent interview with NeurologyLive^®. Kuo emphasized the transformative potential of amyloid and tau PET imaging in diagnosing AD, particularly in challenging cases involving early-stage or atypical presentations. Furthermore, he highlighted the need for clinicians to carefully interpret tau PET results in the context of other diagnostic tools, noting that biomarker staging frameworks can provide critical guidance in clarifying diagnoses, tailoring treatment plans, and optimizing patient care.

REFERENCES
1. Rabinovici GD, Knopman DS, Arbizu J, et al. Updated Appropriate Use Criteria for Amyloid and Tau PET: A Report from the Alzheimer's Association and Society for Nuclear Medicine and Molecular Imaging Workgroup. J Nucl Med. Published online January 8, 2025. doi:10.2967/jnumed.124.268756
2. New Guidance for Gold-Standard Imaging Tests Assists Clinicians in Diagnosis and Management of Alzheimer’s and Other Dementia. News Release. Published January 8, 2024. Accessed January 10, 2024. https://www.alz.org/news/2025/updated-appropriate-use-criteria-amyloid-tau-pet
3. SNMMI and the Alzheimer’s Association Release Updated Appropriate Use Criteria for Amyloid and Tau PET Imaging. News Release. SNMMI. Published January 8, 2024. Accessed January 10, 2024. https://snmmi.org/Web/News/Articles/SNMMI-and-the-Alzheimer-s-Association-Release-Updated-Appropriate-Use-Criteria-for-Amyloid-and-Tau-P

Editor’s Note: Kuo has disclosed that he is a consultant and/or speaker for Attralus, Blue Earth Diagnostics, Chimerix, dGenThera, Eli Lilly, Fusion Pharma, General Electric Healthcare, Invicro, Life Molecular Imaging, Navidea, Novartis, Radionetics, Telix Pharmaceuticals, and United Imaging. He is on the scientific advisory board for dGenThera. He has been a recipient of research grants from Blue Earth Diagnostics and General Electric Healthcare.