title: Using ex vivo proton magnetic resonance spectroscopy to reveal associations between biochemical and biological features of meningiomas.
abstract: OBJECTIVE
  The goal in this study was to determine if proton ((1)H) MR spectroscopy can differentiate meningioma grade and is associated with interpretations of biological behavior; the study was performed using ex vivo high-resolution spectra indicating metabolic characteristics.
  
  
  METHODS
  Sixty-eight resected tissue samples of meningiomas were examined using ex vivo (1)H MR spectroscopy. Of these meningiomas, 46 were WHO Grade I, 14 were WHO Grade II, and 8 were WHO Grade III. Fifty-nine were primary meningiomas and 9 were recurrences. Invasion of adjacent tissue (dura mater, bone, venous sinus, brain) was found in 32 cases. Thirty-nine meningiomas did not rapidly recur (as defined by expansion on MR imaging within a 5-year follow-up period), whereas rapid recurrence was confirmed in 24 meningiomas, and follow-up status was unknown in 5 cases.
  
  
  RESULTS
  The absolute concentrations of total alanine and creatine were decreased in high-grade compared with low-grade meningiomas, as was the ratio of glycine to alanine (all p < 0.05). Additionally, alanine and the glycine/alanine ratio distinguished between primary and recurrent meningiomas (all p < 0.05). Finally, the absolute concentrations of alanine and creatine, and the glycine/alanine and choline/glutamate ratios were associated with rapid recurrence (p < 0.05).
  
  
  CONCLUSIONS
  These data indicate that meningioma tissue can be characterized by metabolic parameters that are not typically identified by histopathological analysis alone. Creatine, glycine, and alanine may be used as markers of meningioma grade, recurrence, and the likelihood of rapid recurrence. These data validate a previous study of a separate group of Grade I meningiomas.
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013, USA.
authors.forename: Wolfgang K
authors.initials: WK
authors.lastname: Pfisterer
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Nieman
authors.forename: Adrienne C
authors.initials: AC
authors.lastname: Scheck
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Coons
authors.forename: Robert F
authors.initials: RF
authors.lastname: Spetzler
authors.forename: Mark C
authors.initials: MC
authors.lastname: Preul
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000409:Alanine / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D018698:Glutamic Acid / Q000378:metabolism; D005998:Glycine / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008577:Meningeal Neoplasms / Q000175:diagnosis* / Q000378:metabolism* / Q000601:surgery; D008579:Meningioma / Q000175:diagnosis* / Q000378:metabolism* / Q000601:surgery; D008875:Middle Aged; D011379:Prognosis
chemical_list: D014408:Biomarkers, Tumor; D018698:Glutamic Acid; D003401:Creatine; D002794:Choline; D000409:Alanine; D005998:Glycine