title: Evaluation of synovial angiogenesis in patients with rheumatoid arthritis using ⁶⁸Ga-PRGD2 PET/CT: a prospective proof-of-concept cohort study.
abstract: BACKGROUND
  The study aimed to evaluate the use of positron emission tomography/computed tomography (PET/CT) with (68)Ga-PRGD2 as the tracer for imaging of synovial angiogenesis in patients with rheumatoid arthritis (RA).
  
  
  METHODS
  Twenty untreated active patients with RA underwent (68)Ga-PRGD2 PET/CT and (18)F-FDG PET/CT before treatment; two patients with osteoarthritis served as controls. Among the 20 patients with RA, 12 repeated the evaluations after 3-month treatment. The image findings were correlated with core variables of disease activity, including the clinical disease activity index (cDAI).
  
  
  RESULTS
  Our findings demonstrated that (68)Ga-PRGD2 specifically accumulated in the synovia with active inflammation rich in neovasculature with high-level αvβ3-integrin expression, but not in the (18)F-FDG-avid inflammatory lymph nodes. In patients with intense (18)F-FDG uptake in muscles caused by arthritic pain, we observed that (68)Ga-PRGD2 PET/CT was better able to evaluate disease severity than (18)F-FDG PET/CT. Both (68)Ga-PRGD2 accumulation and (18)F-FDG uptake changed in response to therapeutic intervention, whereas the changes of (68)Ga-PRGD2, not (18)F-FDG, significantly correlated with clinical measures of changes in the form of cDAI.
  
  
  CONCLUSIONS
  This is the first integrin imaging study conducted in patients with RA that preliminarily indicates the effectiveness of the novel method for evaluating synovial angiogenesis.
  
  
  BACKGROUND
  This study has been registered online at NIH ClinicalTrial.gov (NCT01940926).
authors.affiliation: Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, , Beijing, China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Zhu
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Yin
authors.forename: Kun
authors.initials: K
authors.lastname: Zheng
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Chen
authors.forename: Fengchun
authors.initials: F
authors.lastname: Zhang
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D005682:Gadolinium; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D011868:Radioisotopes; D019275:Radiopharmaceuticals; D013583:Synovial Membrane / Q000098:blood supply* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed
chemical_list: D011868:Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005682:Gadolinium
keywords: Arthritis; Disease Activity; Rheumatoid Arthritis