Quantification of [18F]florbetapir: A test-retest tracer kinetic modelling study

J Cereb Blood Flow Metab. 2019 Nov;39(11):2172-2180. doi: 10.1177/0271678X18783628. Epub 2018 Jun 13.

Abstract

Accumulation of amyloid beta can be visualized using [18F]florbetapir positron emission tomography. The aim of this study was to identify the optimal model for quantifying [18F]florbetapir uptake and to assess test-retest reliability of corresponding outcome measures. Eight Alzheimer's disease patients (age: 67 ± 6 years, Mini-Mental State Examination (MMSE): 23 ± 3) and eight controls (age: 63 ± 4 years, MMSE: 30 ± 0) were included. Ninety-minute dynamic positron emission tomography scans, together with arterial blood sampling, were acquired immediately following a bolus injection of 294 ± 32 MBq [18F]florbetapir. Several plasma input models and the simplified reference tissue model (SRTM) were evaluated. The Akaike information criterion was used to identify the preferred kinetic model. Compared to controls, Alzheimer's disease patients had lower MMSE scores and evidence for cortical Aβ pathology. A reversible two-tissue compartment model with fitted blood volume fraction (2T4k_VB) was the preferred model for describing [18F]florbetapir kinetics. SRTM-derived non-displaceable binding potential (BPND) correlated well (r2 = 0.83, slope = 0.86) with plasma input-derived distribution volume ratio. Test-retest reliability for plasma input-derived distribution volume ratio, SRTM-derived BPND and SUVr(50-70) were r = 0.88, r = 0.91 and r = 0.86, respectively. In vivo kinetics of [18F]florbetapir could best be described by a reversible two-tissue compartmental model and [18F]florbetapir BPND can be reliably estimated using an SRTM.

Keywords: Alzheimer’s disease; Amyloid positron emission tomography; [18F]florbetapir; test–retest; tracer kinetic modelling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alzheimer Disease / diagnostic imaging*
  • Amyloid beta-Peptides / analysis
  • Aniline Compounds / analysis*
  • Case-Control Studies
  • Ethylene Glycols / analysis*
  • Female
  • Fluorine Radioisotopes
  • Humans
  • Kinetics
  • Male
  • Middle Aged
  • Models, Theoretical
  • Positron-Emission Tomography / methods*
  • Radiopharmaceuticals
  • Reproducibility of Results

Substances

  • Amyloid beta-Peptides
  • Aniline Compounds
  • Ethylene Glycols
  • Fluorine Radioisotopes
  • Radiopharmaceuticals
  • florbetapir