Quantitative AV-45 PET imaging for assessing treatment response to lecanemab and deep cervical lymphatic-venous anastomosis in Alzheimer's disease.

OBJECTIVES: This study aimed to validate the clinical utility of visual and software-based quantitative AV-45 PET analyses and compare treatment effects between lecanemab and deep cervical lymphatic-venous anastomosis (dcLVA). METHODS: This retrospective cohort study included Alzheimer's disease patients who received 6-month lecanemab therapy or dcLVA surgery between July 2024 and 2025. AV-45 PET was performed 1 week before and 6 months after treatment. Standardized uptake value ratios (SUVRs) and centiloids (CLs) were obtained using visual and quantitative analyses. Agreement was assessed using Cohen's κ and intraclass correlation coefficients (ICC). Receiver operating characteristic (ROC) analysis evaluated diagnostic performance. Logistic regression used Informant Questionnaire on Cognitive Decline in the Elderly score greater than or equal to 3.3 as the outcome. RESULTS: Baseline characteristics were comparable between groups (all P > 0.05). Visual assessment showed good agreement with centiloid quantification (κ = 0.72, ICC = 0.663). ROC analysis identified ΔCL as the optimal marker (area under the curve = 0.764, P = 0.026), with a cutoff of -11.5%. ΔCL ≥ -11.5% independently predicted cognitive decline in the lecanemab group (odds ratio = 10.281, 95% confidence interval = 1.289-82.005; P = 0.028). Cognitive decline was less frequent in the lecanemab group (23.5 vs. 81.8%; P < 0.001). ΔCL differed significantly between groups (P = 0.006), whereas ΔSUVR did not. CONCLUSION: Visual and centiloid-based AV-45 PET analyses show good concordance for monitoring Alzheimer's disease treatment response. ΔCL is a robust marker of lecanemab efficacy, which is superior to dcLVA in reducing amyloid-β burden and delaying cognitive decline.