title: Noninvasive evaluation of the malignant potential of intracranial meningiomas performed using proton magnetic resonance spectroscopy.
abstract: OBJECTIVE
  Controversy exists about correlations between histological tumor grade and magnetic resonance (MR) spectroscopy data. The authors studied single-voxel proton MR spectroscopy as a noninvasive way to evaluate grade of malignancy in intracranial meningiomas.
  
  
  METHODS
  The authors compared the results of MR spectroscopy with those derived by the MIB-1 staining index (SI) in 29 meningiomas. Proton MR spectroscopy was performed using stimulated echo acquisition and volume-localized solvent-attenuated proton nuclear MR sequences before surgery or other therapy. Twenty-four tumors were histologically benign (13 meningothelial, three fibrous, four transitional, three angiomatous, and one chordoid); four were atypical (Grade II), and one was papillary (Grade III). The mean MIB-1 SI in the benign group was significantly lower than those in the other groups (p = 0.0041). The mean choline-containing compound (Cho)/ creatine and phosphocreatine (Cr) ratios in the benign and nonbenign groups were 2.56+/-1.26 and 7.85+/-3.23, respectively (p = 0.0002). A significant linear correlation was observed between the Cho/Cr ratio and the MIB-1 SI (r0.05 = 0.74, p<0.001). Necrosis was present histologically in four of the five meningiomas classified either as atypical or papillary. Magnetic resonance spectroscopy revealed a methylene signal in these meningiomas that was not detected in benign meningiomas. Of the five meningiomas in which only a lactate signal was observed, two were benign and the MIB-1 SI in these two benign meningiomas was higher than the mean value for the benign group. Alanine, detected in 12 of 30 meningiomas, did not correlate with either tumor grade or Cho/Cr ratio.
  
  
  CONCLUSIONS
  Proton MR spectroscopy is a useful diagnostic method for determining the proliferative or malignant potential of meningiomas according to the Cho/Cr ratio. A lactate and/or methylene signal suggests a high-grade tumor.
authors.affiliation: Department of Neurosurgery and Molecular Neuroscience Research Center, Shiga University of Medical Science, Ohtsu, Japan. shiino@belle.shiga-med.ac.jp
authors.forename: A
authors.initials: A
authors.lastname: Shino
authors.forename: S
authors.initials: S
authors.lastname: Nakasu
authors.forename: M
authors.initials: M
authors.lastname: Matsuda
authors.forename: J
authors.initials: J
authors.lastname: Handa
authors.forename: S
authors.initials: S
authors.lastname: Morikawa
authors.forename: T
authors.initials: T
authors.lastname: Inubushi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D034961:Antigens, Nuclear; D014408:Biomarkers, Tumor / Q000378:metabolism; D001921:Brain / Q000473:pathology; D002455:Cell Division / Q000502:physiology; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D003937:Diagnosis, Differential; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D006838:Hydrocarbons; D019394:Ki-67 Antigen; D019344:Lactic Acid / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology* / Q000601:surgery; D008578:Meninges / Q000473:pathology; D008579:Meningioma / Q000473:pathology* / Q000601:surgery; D008697:Methane / Q000031:analogs & derivatives / Q000378:metabolism; D008875:Middle Aged; D009336:Necrosis; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000601:surgery; D009687:Nuclear Proteins / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D011379:Prognosis; D012086:Reoperation
chemical_list: D034961:Antigens, Nuclear; D014408:Biomarkers, Tumor; D006838:Hydrocarbons; D019394:Ki-67 Antigen; D009687:Nuclear Proteins; D010725:Phosphocreatine; C030011:carbene; D019344:Lactic Acid; D003401:Creatine; D002794:Choline; D008697:Methane