Assessing Amyloid Pathology in Cognitively Normal Subjects Using 18 F-Flutemetamol PET: Comparing Visual Reads and Quantitative Methods

Main Authors: Lyduine E. Collij, Elles Konijnenberg, Juhan Reimand, Mara ten Kate, Anouk den Braber, Isadora Lopes Alves, Marissa Zwan, Maqsood Yaqub, Daniëlle M.E. van Assema, Alle Meije Wink, Adriaan A. Lammertsma, Philip Scheltens, Pieter Jelle Visser, Frederik Barkhof, Bart N.M. van Berckel
Format: Article Journal
Terbitan: , 2019
Subjects:
Online Access: https://zenodo.org/record/4675384
Daftar Isi:
  • Abstract: Our objective was to determine the optimal approach for assessing amyloid disease in a cognitively normal elderly population. Methods: Dynamic 18F-flutemetamol PET scans were acquired using a coffee-break protocol (a 0- to 30-min scan and a 90- to 110-min scan) on 190 cognitively normal elderly individuals (mean age, 70.4 y; 60% female). Parametric images were generated from SUV ratio (SUVr) and nondisplaceable binding potential (BPND) methods, with cerebellar gray matter as a reference region, and were visually assessed by 3 trained readers. Interreader agreement was calculated using κ-statistics, and semiquantitative values were obtained. Global cutoffs were calculated for both SUVr and BPND using a receiver-operating-characteristic analysis and the Youden index. Visual assessment was related to semiquantitative classifications. Results: Interreader agreement in visual assessment was moderate for SUVr (κ = 0.57) and good for BPND images (κ = 0.77). There was discordance between readers for 35 cases (18%) using SUVr and for 15 cases (8%) using BPND, with 9 overlapping cases. For the total cohort, the mean (±SD) SUVr and BPND were 1.33 (±0.21) and 0.16 (±0.12), respectively. Most of the 35 cases (91%) for which SUVr image assessment was discordant between readers were classified as negative based on semiquantitative measurements. Conclusion: The use of parametric BPND images for visual assessment of 18F-flutemetamol in a population with low amyloid burden improves interreader agreement. Implementing semiquantification in addition to visual assessment of SUVr images can reduce false-positive classification in this population.
  • This project received funding from the EU/EFPIA Innovative Medicines Initiative (IMI) Joint Undertaking (EMIF grant 115372) and the EU-EFPIA IMI-2 Joint Undertaking (grant 115952). This joint undertaking receives support from the European Union's Horizon 2020 research and innovation program and EFPIA. Support was also received from the NIHR UCLH Biomedical Research Center, and in-kind sponsoring of the PET tracer was received from GE Healthcare. This publication solely reflects the author's view and neither IMI nor the European Union, and EFPIA are responsible for any use that may be made of the information contained herein.