title: Carbon-11-methionine PET imaging of choroidal melanoma and the time course after carbon ion beam radiotherapy.
abstract: The aim of this study was to assess the feasibility of MET-PET as an evaluation method of the therapeutic effect of carbon ion beam radiotherapy.
  
  
  METHODS
  Twenty-four choroidal melanoma patients who were treated with a carbon ion beam underwent at least three MET-PET scans before and after therapy. The uptake was visually and semiquantitatively evaluated on the basis of the tumor-to-brain ratio (TBR).
  
  
  RESULTS
  The accumulation was significantly decreased at 6 months or more after therapy and disappeared in 50% of the patients at 12 months after therapy. The baseline TBR, 1, 6, 12 and 24 months after therapy averaged 1.88+/-0.65, 1.73+/-0.52, 1.08+/-0.42, 0.67+/-0.27 and 0.65+/-0.30, respectively. TBR was significantly decreased at 6 months or more after therapy.
  
  
  CONCLUSIONS
  MET-PET may be an alternative method for evaluating the effect of radiotherapy.
authors.affiliation: Clinical Diagnosis Section, Research Center, Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba-shi, Chiba-ken, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Tamura
authors.forename: Kyosan
authors.initials: K
authors.lastname: Yoshikawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Hasebe
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsuji
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yanagi
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Suzuki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kubo
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Tsujii
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002250:Carbon Radioisotopes; D002830:Choroid Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D008715:Methionine; D008875:Middle Aged; D011877:Radionuclide Imaging; D016896:Treatment Outcome
chemical_list: D002250:Carbon Radioisotopes; D008715:Methionine