title: Multicenter Reproducibility of 18F-Fluciclatide PET Imaging in Subjects with Solid Tumors.
abstract: Integrins are upregulated on both tumor cells and associated vasculature, where they play an important role in angiogenesis and metastasis. Fluciclatide is an arginine-glycine-aspartic acid peptide with high affinity for αvβ3/αvβ5 integrin, which can be radiolabeled for PET imaging of angiogenesis. Thus, (18)F-fluciclatide is a potential biomarker of therapeutic response to antiangiogenic inhibitors. The aim of this study was to evaluate the reproducibility of (18)F-fluciclatide in multiple solid-tumor types.
  
  
  METHODS
  Thirty-nine patients underwent PET/CT scanning at 40, 65, and 90 min after injection of (18)F-fluciclatide (maximum, 370 MBq) on 2 separate days (2-9 d apart). Patients did not receive any therapy between PET/CT scans. (18)F-fluciclatide images were reported and quantitative measures of uptake were extracted using the PERCIST methodology. Intrasubject reproducibility of PET uptake in all measurable lesions was evaluated by calculating relative differences in SUV between PET scans for each lesion during the 2 imaging sessions.
  
  
  RESULTS
  Thirty-nine measurable lesions were detected in 26 patients. Lesion uptake correlated strongly across imaging sessions (r = 0.92, P < 0.05, at 40 min; r = 0.94, P < 0.05, at 65 min; r = 0.94, P < 0.05, at 90 min) with a mean relative difference and SD of the relative difference of 0.006 ± 0.18 at 40 min, 0.003 ± 0.19 at 65 min, and 0.025 ± 0.20 at 90 min. This reflects 95% limits of repeatability of 35%-39% for the difference between the 2 SUV measurements or a variability of 18%-20% in agreement from that observed in well-calibrated multicenter (18)F-FDG studies.
  
  
  CONCLUSIONS
  The test-retest reproducibility of (18)F-fluciclatide across multiple tumor types has been measured and shown to be acceptable. This is an important step in the development of this in vivo biomarker to identify and quantify response to antiangiogenic therapy in cancer patients.
authors.affiliation: Department of Experimental Medicine, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, United Kingdom.
authors.forename: Rohini
authors.initials: R
authors.lastname: Sharma
authors.affiliation: PETCT and Cyclotron Department, HCG, Bangalore, India.
authors.forename: Kumar G
authors.initials: KG
authors.lastname: Kallur
authors.affiliation: Department of Nuclear Medicine, Asan Medical Center, Seoul, South Korea.
authors.forename: Jin S
authors.initials: JS
authors.lastname: Ryu
authors.affiliation: Department of Nuclear Medicine and PET-CT Division, Manipal Hospital, Bangalore, India.
authors.forename: Ramanathapuram V
authors.initials: RV
authors.lastname: Parameswaran
authors.affiliation: Uppsala University Hospital, Department of Oncology, Uppsala, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Lindman
authors.affiliation: Department of Nuclear Medicine, Barts Health, Queen Mary University of London, London, United Kingdom.
authors.forename: Norbert
authors.initials: N
authors.lastname: Avril
authors.affiliation: Department of Radiology, Churchill Hospital, Oxford Radcliffe Hospitals Trust, Oxford, United Kingdom.
authors.forename: Fergus V
authors.initials: FV
authors.lastname: Gleeson
authors.affiliation: Department of Nuclear Medicine, Yonsei University Health System, Seoul, Korea.
authors.forename: Jong D
authors.initials: JD
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Seoul, Korea.
authors.forename: Kyung-Han
authors.initials: KH
authors.lastname: Lee
authors.affiliation: PET Imaging Centre, Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: O'Doherty
authors.affiliation: Institute of Nuclear Medicine, University College London, London, United Kingdom.
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Groves
authors.affiliation: GE Healthcare Life Sciences, Imaging R&D, Amersham, United Kingdom; and.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Miller
authors.affiliation: GE Healthcare Life Sciences, Imaging R&D, Amersham, United Kingdom; and.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Somer
authors.affiliation: Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, United Kingdom.
authors.forename: Charles R
authors.initials: CR
authors.lastname: Coombes
authors.affiliation: Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, United Kingdom eric.aboagye@imperial.ac.uk.
authors.forename: Eric O
authors.initials: EO
authors.lastname: Aboagye
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy; D010455:Peptides; D011092:Polyethylene Glycols; D049268:Positron-Emission Tomography / Q000379:methods*; D011786:Quality Control; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results
chemical_list: C530281:AH 111585; D020533:Angiogenesis Inhibitors; D010455:Peptides; D019275:Radiopharmaceuticals; D011092:Polyethylene Glycols
keywords: 18F-fluciclatide; angiogenesis; cancer; reproducibility