title: Diagnostic and Prognostic Value of 11C-Methionine PET for Nonenhancing Gliomas.
abstract: OBJECTIVE
  Noninvasive radiologic evaluation of glioma can facilitate correct diagnosis and detection of malignant transformation. Although positron-emission tomography is considered valuable in the care of patients with gliomas, (18)F-fluorodeoxyglucose and (11)C-methionine have reportedly shown ambiguous results in terms of grading and prognostication. The present study compared the diagnostic and prognostic capabilities of diffusion tensor imaging, FDG, and (11)C-methionine PET in nonenhancing gliomas.
  
  
  METHODS
  Thirty-five consecutive newly diagnosed, histologically confirmed nonenhancing gliomas that underwent both FDG and (11)C-methionine PET were retrospectively investigated (23 grade II and 12 grade III gliomas). Apparent diffusion coefficient, fractional anisotropy, and tumor-to-normal tissue ratios of both FDG and (11)C-methionine PET were compared between grade II and III gliomas. Prognostic values of these parameters were also tested by using progression-free survival.
  
  
  RESULTS
  Grade III gliomas showed significantly higher average tumor-to-normal tissue and maximum tumor2-to-normal tissue than grade II gliomas in (11)C-methionine (P = .013, P = .0017, respectively), but not in FDG-PET imaging. There was no significant difference in average ADC, minimum ADC, average fractional anisotropy, and maximum fractional anisotropy. (11)C-methionine PET maximum tumor-to-normal tissue ratio of 2.0 was most suitable for detecting grade III gliomas among nonenhancing gliomas (sensitivity, 83.3%; specificity, 73.9%). Among patients not receiving any adjuvant therapy, median progression-free survival was 64.2 ± 7.2 months in patients with maximum tumor-to-normal tissue ratio of <2.0 for (11)C-methionine PET and 18.6 ± 6.9 months in patients with maximum tumor-to-normal tissue ratio of >2.0 (P = .0044).
  
  
  CONCLUSIONS
  (11)C-methionine PET holds promise for World Health Organization grading and could offer a prognostic imaging biomarker for nonenhancing gliomas.
authors.affiliation: From the Department of Neurosurgery (K.T., M.K.), Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan Departments of Neurosurgery (K.T., M.K., H.A., Y.C., N.K., H.K., N.H., T.Y.).
authors.forename: K
authors.initials: K
authors.lastname: Takano
authors.affiliation: From the Department of Neurosurgery (K.T., M.K.), Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan Departments of Neurosurgery (K.T., M.K., H.A., Y.C., N.K., H.K., N.H., T.Y.) m-kinoshita@nsurg.med.osaka-u.ac.jp.
authors.forename: M
authors.initials: M
authors.lastname: Kinoshita
authors.affiliation: Departments of Neurosurgery (K.T., M.K., H.A., Y.C., N.K., H.K., N.H., T.Y.).
authors.forename: H
authors.initials: H
authors.lastname: Arita
authors.affiliation: Department of Neurosurgery (Y.O., Y.K., M.N., S.N.).
authors.forename: Y
authors.initials: Y
authors.lastname: Okita
authors.affiliation: Departments of Neurosurgery (K.T., M.K., H.A., Y.C., N.K., H.K., N.H., T.Y.) Department of Neurosurgery (Y.C.), Kansai Rosai Hospital, Itami, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Chiba
authors.affiliation: Departments of Neurosurgery (K.T., M.K., H.A., Y.C., N.K., H.K., N.H., T.Y.).
authors.forename: N
authors.initials: N
authors.lastname: Kagawa
authors.affiliation: Department of Neurosurgery (Y.F.), Osaka Neurological Institute, Osaka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujimoto
authors.affiliation: Departments of Neurosurgery (K.T., M.K., H.A., Y.C., N.K., H.K., N.H., T.Y.).
authors.forename: H
authors.initials: H
authors.lastname: Kishima
authors.affiliation: Department of Neurosurgery (Y.O., Y.K., M.N., S.N.) Division of Regenerative Medicine (Y.K.), Institute for Clinical Research, Osaka National Hospital, National Hospital Organization, Osaka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kanemura
authors.affiliation: Department of Neurosurgery (Y.O., Y.K., M.N., S.N.) Department of Neurosurgery (M.N.), Kansai Medical University, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nonaka
authors.affiliation: Department of Neurosurgery (Y.O., Y.K., M.N., S.N.).
authors.forename: S
authors.initials: S
authors.lastname: Nakajima
authors.affiliation: Nuclear Medicine and Tracer Kinetics (E.S., J.H.), Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Shimosegawa
authors.affiliation: Nuclear Medicine and Tracer Kinetics (E.S., J.H.), Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Hatazawa
authors.affiliation: Departments of Neurosurgery (K.T., M.K., H.A., Y.C., N.K., H.K., N.H., T.Y.).
authors.forename: N
authors.initials: N
authors.lastname: Hashimoto
authors.affiliation: Departments of Neurosurgery (K.T., M.K., H.A., Y.C., N.K., H.K., N.H., T.Y.).
authors.forename: T
authors.initials: T
authors.lastname: Yoshimine
mesh_terms: D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality; D002250:Carbon Radioisotopes; D018572:Disease-Free Survival; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000401:mortality; D006801:Humans; D008297:Male; D008715:Methionine; D008875:Middle Aged; D060787:Neoplasm Grading / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D008715:Methionine