title: Peritumoral Brain Edema in Meningiomas Depends on Aquaporin-4 Expression and Not on Tumor Grade, Tumor Volume, Cell Count, or Ki-67 Labeling Index.
abstract: The aim of this study was to investigate to which degree the peritumoral brain edema in patients with meningiomas depends on aquaporin-4 (AQP4) expression, tumor grade, tumor volume, Ki-67 expression, and cell count.
  
  
  
  Thirty-three patients (25 women, 8 men; mean age 56.6 ± 16.0 years) with an intracranial meningioma underwent a standardized magnetic resonance (MR) examination prior to surgical resection. Edema indices (EIs) and tumor volumes were measured on the MR images. Tumor grade was classified according to the World Health Organization, and the proliferation index was estimated on Ki-67 antigen-stained specimens. Tumor cell count was evaluated. Eighteen specimens were stained for AQP4 expressioon.
  
  
  
  Significant intergroup differences between AQP4 expression grades and EIs were observed (P = 0.03), and a positive correlation was detected between EIs and AQP4 expression grades (r = 0.54; P < 0.05). A ROC analysis with EI as a test variable revealed an AUC of 0.77 (95 % CI 0.55-0.99) for the prediction of a moderate-to-strong AQP4 expression. An EI ≥1.5 predicted a moderate-to-high AQP4 expression with a sensitivity of 77 % and a specificity of 60 %. EI values of 2.2 and 3.5 reached sensitivity/specificity values of 69/80 % and 54/100 %, respectively. The AQP4 expression did not show any significant correlations with tumor grading, tumor volume, Ki-67 expression, or cell count. Moreover, we observed no significant positive or negative correlations between the EI and tumor grading (P = 0.7), tumor volume (P = 0.19), Ki-67 index (P = 0.9), and cell count (P = 0.34).
  
  
  
  Peritumoral brain edema in patients with meningiomas may depend on AQP4 expression grades and not on tumor grade, tumor volume, Ki-67 expression, and cell count. The amount of edema predicted AQP4 expressions with moderate-to-good sensitivity and specificity.
authors.affiliation: Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany. matthias.gawlitza@medizin.uni-leipzig.de.
authors.forename: Matthias
authors.identifier: 0000-0002-1229-3352
authors.initials: M
authors.lastname: Gawlitza
authors.affiliation: Department of Dermatology, Martin Luther University Halle-Wittenberg, Halle, Germany.
authors.forename: Eckhard
authors.initials: E
authors.lastname: Fiedler
authors.affiliation: Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schob
authors.affiliation: Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.
authors.forename: Karl-Titus
authors.initials: KT
authors.lastname: Hoffmann
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.|Department of Radiology, Martin Luther University Halle-Wittenberg, Halle, Germany.
authors.forename: Alexey
authors.initials: A
authors.lastname: Surov
mesh_terms: D051401:Aquaporin 4 / Q000378:metabolism*; D001921:Brain / Q000473:pathology; D001929:Brain Edema / Q000378:metabolism* / Q000473:pathology; D002452:Cell Count; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000378:metabolism* / Q000473:pathology; D008579:Meningioma / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D060787:Neoplasm Grading; D012372:ROC Curve; D013194:Staining and Labeling; D047368:Tumor Burden
chemical_list: D051401:Aquaporin 4; D019394:Ki-67 Antigen
keywords: Aquaporin-4; Brain edema; Meningioma