Feasibility of short imaging protocols for [ 18 F]PI-2620 tau-PET in progressive supranuclear palsy

Eur J Nucl Med Mol Imaging. 2021 Nov;48(12):3872-3885. doi: 10.1007/s00259-021-05391-3. Epub 2021 May 22.

Abstract

Purpose: Dynamic 60-min positron emission tomography (PET) imaging with the novel tau radiotracer [18F]PI-2620 facilitated accurate discrimination between patients with progressive supranuclear palsy (PSP) and healthy controls (HCs). This study investigated if truncated acquisition and static time windows can be used for [18F]PI-2620 tau-PET imaging of PSP.

Methods: Thirty-seven patients with PSP Richardson syndrome (PSP-RS) were evaluated together with ten HCs. [18F]PI-2620 PET was performed by a dynamic 60-min scan. Distribution volume ratios (DVRs) were calculated using full and truncated scan durations (0-60, 0-50, 0-40, 0-30, and 0-20 min p.i.). Standardized uptake value ratios (SUVrs) were obtained 20-40, 30-50, and 40-60 min p.i.. All DVR and SUVr data were compared with regard to their potential to discriminate patients with PSP-RS from HCs in predefined subcortical and cortical target regions (effect size, area under the curve (AUC), multi-region classifier).

Results: 0-50 and 0-40 DVR showed equivalent effect sizes as 0-60 DVR (averaged Cohen's d: 1.22 and 1.16 vs. 1.26), whereas the performance dropped for 0-30 or 0-20 DVR. The 20-40 SUVr indicated the best performance of all static acquisition windows (averaged Cohen's d: 0.99). The globus pallidus internus discriminated patients with PSP-RS and HCs at a similarly high level for 0-60 DVR (AUC: 0.96), 0-40 DVR (AUC: 0.96), and 20-40 SUVr (AUC: 0.94). The multi-region classifier sensitivity of these time windows was consistently 86%.

Conclusion: Truncated and static imaging windows can be used for [18F]PI-2620 PET imaging of PSP. 0-40 min dynamic scanning offers the best balance between accuracy and economic scanning.

Keywords: Progressive supranuclear palsy; Tau-PET; Time window; [18F]PI-2620.

MeSH terms

  • Alzheimer Disease*
  • Feasibility Studies
  • Humans
  • Positron-Emission Tomography
  • Supranuclear Palsy, Progressive* / diagnostic imaging
  • tau Proteins

Substances

  • tau Proteins