TY - JOUR
T1 - Impact of simulated reduced injected dose on the assessment of amyloid PET scans
AU - Young, Peter
AU - Heeman, Fiona
AU - Axelsson, Jan
AU - Collij, Lyduine E.
AU - Hitzel, Anne
AU - Sanaat, Amirhossein
AU - Niñerola-Baizan, Aida
AU - Perissinotti, Andrés
AU - Lubberink, Mark
AU - Frisoni, Giovanni B.
AU - Zaidi, Habib
AU - Barkhof, Frederik
AU - Farrar, Gill
AU - Baker, Suzanne
AU - Gispert, Juan Domingo
AU - Garibotto, Valentina
AU - Rieckmann, Anna
AU - Schöll, Michael
N1 - Funding Information: Open access funding provided by University of Gothenburg. 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. This communication reflects the views of the authors and neither IMI nor the European Union and EFPIA are liable for any use that may be made of the information contained herein. Publisher Copyright: © 2023, The Author(s).
PY - 2023
Y1 - 2023
N2 - Purpose: To investigate the impact of reduced injected doses on the quantitative and qualitative assessment of the amyloid PET tracers [18F]flutemetamol and [18F]florbetaben. Methods: Cognitively impaired and unimpaired individuals (N = 250, 36% Aβ-positive) were included and injected with [18F]flutemetamol (N = 175) or [18F]florbetaben (N = 75). PET scans were acquired in list-mode (90–110 min post-injection) and reduced-dose images were simulated to generate images of 75, 50, 25, 12.5 and 5% of the original injected dose. Images were reconstructed using vendor-provided reconstruction tools and visually assessed for Aβ-pathology. SUVRs were calculated for a global cortical and three smaller regions using a cerebellar cortex reference tissue, and Centiloid was computed. Absolute and percentage differences in SUVR and CL were calculated between dose levels, and the ability to discriminate between Aβ- and Aβ + scans was evaluated using ROC analyses. Finally, intra-reader agreement between the reduced dose and 100% images was evaluated. Results: At 5% injected dose, change in SUVR was 3.72% and 3.12%, with absolute change in Centiloid 3.35CL and 4.62CL, for [18F]flutemetamol and [18F]florbetaben, respectively. At 12.5% injected dose, percentage change in SUVR and absolute change in Centiloid were < 1.5%. AUCs for discriminating Aβ- from Aβ + scans were high (AUC ≥ 0.94) across dose levels, and visual assessment showed intra-reader agreement of > 80% for both tracers. Conclusion: This proof-of-concept study showed that for both [18F]flutemetamol and [18F]florbetaben, adequate quantitative and qualitative assessments can be obtained at 12.5% of the original injected dose. However, decisions to reduce the injected dose should be made considering the specific clinical or research circumstances.
AB - Purpose: To investigate the impact of reduced injected doses on the quantitative and qualitative assessment of the amyloid PET tracers [18F]flutemetamol and [18F]florbetaben. Methods: Cognitively impaired and unimpaired individuals (N = 250, 36% Aβ-positive) were included and injected with [18F]flutemetamol (N = 175) or [18F]florbetaben (N = 75). PET scans were acquired in list-mode (90–110 min post-injection) and reduced-dose images were simulated to generate images of 75, 50, 25, 12.5 and 5% of the original injected dose. Images were reconstructed using vendor-provided reconstruction tools and visually assessed for Aβ-pathology. SUVRs were calculated for a global cortical and three smaller regions using a cerebellar cortex reference tissue, and Centiloid was computed. Absolute and percentage differences in SUVR and CL were calculated between dose levels, and the ability to discriminate between Aβ- and Aβ + scans was evaluated using ROC analyses. Finally, intra-reader agreement between the reduced dose and 100% images was evaluated. Results: At 5% injected dose, change in SUVR was 3.72% and 3.12%, with absolute change in Centiloid 3.35CL and 4.62CL, for [18F]flutemetamol and [18F]florbetaben, respectively. At 12.5% injected dose, percentage change in SUVR and absolute change in Centiloid were < 1.5%. AUCs for discriminating Aβ- from Aβ + scans were high (AUC ≥ 0.94) across dose levels, and visual assessment showed intra-reader agreement of > 80% for both tracers. Conclusion: This proof-of-concept study showed that for both [18F]flutemetamol and [18F]florbetaben, adequate quantitative and qualitative assessments can be obtained at 12.5% of the original injected dose. However, decisions to reduce the injected dose should be made considering the specific clinical or research circumstances.
KW - Alzheimer’s disease
KW - Amyloid
KW - Dose reduction
KW - Neuroimaging
KW - PET
UR - http://www.scopus.com/inward/record.url?scp=85175066219&partnerID=8YFLogxK
U2 - https://doi.org/10.1007/s00259-023-06481-0
DO - https://doi.org/10.1007/s00259-023-06481-0
M3 - Article
C2 - 37897616
SN - 1619-7070
JO - European journal of nuclear medicine and molecular imaging
JF - European journal of nuclear medicine and molecular imaging
ER -