title: Evaluation of semi-quantitative method for quantification of dopamine transporter in human PET study with ¹⁸F-FE-PE2I.
abstract: OBJECTIVE
  Positron emission tomography (PET) with ¹⁸F-FE-PE2I is useful for investigating the function of dopamine transporter, and kinetics of ¹⁸F-FE-PE2I could be described by standard two-tissue compartment model (2CM) using plasma input function. In this study, we investigated the feasibility of semi-quantitative methods for estimating binding potential (BPND) and transporter occupancy to shorten the scan period and to reduce the effect of statistical noise on quantitative outcomes using computer simulation and human PET studies with ¹⁸F-FE-PE2I.
  
  
  METHODS
  In the simulations, time-activity curves (TACs) for the putamen with a wide range of BPND were generated. In these TACs, BPNDs were estimated by standardized uptake value ratio (SUVR) using various integration intervals and the simplified reference tissue model (SRTM) with the cerebellum as reference region, and reduction of BPND assuming transporter occupancy by antipsychotics was calculated from BPND obtained from TACs with various BPND values. These estimates were evaluated by comparison with those of 2CM. In human studies with normal volunteers, BPNDs were estimated in the caudate and putamen using SUVR and SRTM with the cerebellar reference region, and compared with BPND by standard 2CM.
  
  
  RESULTS
  In the simulations, BPND estimated by SUVR with late time frames and SRTM showed linear correlation with those by 2CM, although the estimates by SUVR were overestimated and affected by the cerebral blood flow as BPND became higher. As for transporter occupancy, SRTM showed higher linearity with 2CM and less effect of statistical noise than the SUVR method. In human studies, BPND by SRTM and SUVR with late time frames showed good correlation with BPND by 2CM.
  
  
  CONCLUSIONS
  Although SRTM is more reliable than the SUVR method for BPND and occupancy estimation, SUVR using late time frames has the potential to provide practical indices of BPND and occupancy with a shorter scan period.
authors.affiliation: Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan. ikoma@nirs.go.jp.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ikoma
authors.affiliation: Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sasaki
authors.affiliation: Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kimura
authors.affiliation: Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Seki
authors.affiliation: Department of Neuropsychiatry, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8602, Japan.
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Okubo
authors.affiliation: Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Suhara
authors.affiliation: Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.|Advanced Clinical Research Center, Fukushima Medical University, 1 Hikariga-oka, Fukushima, 960-1295, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
mesh_terms: D000328:Adult; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D009662:Nortropanes; D049268:Positron-Emission Tomography / Q000379:methods*; D059629:Signal-To-Noise Ratio; D055815:Young Adult
chemical_list: C543996:(E)-N-(3-iodoprop-2-enyl)-2beta-carbofluoroethoxy-3beta-(4'-methyl-phenyl) nortropane; D050483:Dopamine Plasma Membrane Transport Proteins; D009662:Nortropanes
keywords: 18F-FE-PE2I; Binding potential; Occupancy; Positron emission tomography; Standardized uptake value ratio (SUVR)