Assessment of ¹⁸F-Florbetaben Amyloid PET Imaging in Patients with Suspected Alzheimer’s Disease and Isolated Increase in Cerebrospinal Fluid Tau Proteins

Article type: Research Article

Authors: Manca, Chloé^a | Hopes, Lucie^b | Kearney-Schwartz, Anna^c | Roch, Véronique^a | Karcher, Gilles^a | Baumann, Cédric^d | Marie, Pierre-Yves^{a; e} | Malaplate-Armand, Catherine^f | Jonveaux, Thérèse Rivasseau^c | Verger, Antoine^{a; g; *}

Affiliations: [a] Department of Nuclear Medicine and Nancyclotep Imaging Platform, CHRU-Nancy, Lorraine University, Nancy, France | [b] Department of Neurology, CHRU-Nancy, Lorraine University, Nancy, France | [c] Department of Geriatrics, CHRU-Nancy, Lorraine University, Nancy, France | [d] CHRU-Nancy, Methodological and Biostatistical Support Unit, Platform of Clinical Research Support PARC, Nancy, France | [e] INSERM, Lorraine University, DCAC, Nancy, INSERM U1116, France | [f] Department of Biochemistry, CHRU-Nancy, Lorraine University, Molecular Biology and Nutrition, Nancy, France | [g] IADI, INSERM, Lorraine University, Nancy, INSERM U1254, France

Correspondence: [*] Correspondence to: Antoine Verger, Service de de Médecine Nucléaire, rue du Morvan, 54500 Vandoeuvre-les-Nancy, France. Tel.: +33 4383153911; Fax: +33 383153839; E-mail: a.verger@chru-nancy.fr.

Abstract: Background/Objective:The aim of this study was to assess, in routine, the rates with which an amyloid deposition was documented by 18F-florbetaben PET in patients with suspected Alzheimer’s disease (AD) but with isolated increases in cerebrospinal fluid (CSF) tau-protein concentrations, and the subsequent impact of these PET results on medical management. Methods:This prospective study included 34 patients with mild neurocognitive disorders (MND) and suspected AD (73±9 years, 16 women) and with abnormal CSF concentrations in total-tau (T-tau) and/or phosphorylated-tau (P-tau) proteins but normal Aβ42 concentration and Aβ42/Aβ40 ratio. These patients were referred to 8F-florbetaben PET from which the PET-related changes in the confidence for AD diagnosis (low, intermediate, or high) and treatments were reported. Results:The PET examinations were positive for amyloid deposition (brain amyloid plaque load, BAPL score >1) in none of the 9 patients with an increase in only T-tau proteins and in 8 among the 25 (32%) with an increase in P-tau proteins (one BAPL score of 2 and seven BAPL scores of 3). Knowledge of the PET results was associated with subsequent changes in diagnostic confidence in 44% of patients (15/34) and in the intention-to-treat with a cholinesterase inhibitor drug in 18% (6/34). Conclusion:In patients with suspected AD and isolated increase in CSF tau protein concentrations, an amyloid deposition is documented by 18F-florbetaben PET in as much as one third of cases when the concentration of P-tau is abnormal, and PET results are associated with significant further changes in medical management.

Keywords: Alzheimer’s disease, amyloid, cerebrospinal fluid, positron emission tomography

DOI: 10.3233/JAD-181146

Journal: Journal of Alzheimer's Disease, vol. 68, no. 3, pp. 1061-1069, 2019