title: Principal risk of peritumoral edema after stereotactic radiosurgery for intracranial meningioma is tumor-brain contact interface area.
abstract: OBJECTIVE
  Stereotactic radiosurgery (SRS) of meningiomas is associated with posttreatment peritumoral edema (PTE). The purpose of this study was to evaluate the prevalence and risk factors of post-SRS PTE for intracranial meningiomas.
  
  
  METHODS
  A total of 163 patients with 182 meningiomas treated with SRS were retrospectively reviewed. Tumors were divided into 4 pre-SRS groups according to whether they had undergone previous surgery and whether they had preexisting PTE. Several risk factors were investigated by univariate and multivariate analysis in all tumors, tumors without previous surgery, tumors without preexisting PTE, and preexisting PTE.
  
  
  RESULTS
  Of 182 tumors, 45 (24.7%) developed post-SRS PTE. Compared with tumors without preexisting PTE, the odds of developing post-SRS PTE in tumors with preexisting PTE were 6.0 times higher in all tumors, and 6.9 times higher in tumors without previous surgery. A 1-cm2 increase in tumor-brain contact interface area increased the odds of developing post-SRS PTE by 17% in all tumors, 16% in tumors without previous surgery, and 26% in tumors without preexisting PTE. Of 118 tumors without previous surgery, 13 had preexisting PTE, the existence of which had a significant relationship to both tumor-brain contact interface area and tumor volume.
  
  
  CONCLUSIONS
  Post-SRS PTE is common in patients with meningioma. Tumor-brain contact interface area and preexisting PTE were the most significant risk factors for post-SRS PTE. Tumor volume and tumor-brain contact interface area were significant risk factors for the development of preexisting PTE.
authors.affiliation: Department of Neurological Surgery, Brain Tumor and Neuro-Oncology Center, Neurological Institute, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
authors.forename: Rongsheng
authors.initials: R
authors.lastname: Cai
authors.forename: Gene H
authors.initials: GH
authors.lastname: Barnett
authors.forename: Eric
authors.initials: E
authors.lastname: Novak
authors.forename: Samuel T
authors.initials: ST
authors.lastname: Chao
authors.forename: John H
authors.initials: JH
authors.lastname: Suh
mesh_terms: D000368:Aged; D004307:Dose-Response Relationship, Radiation; D004487:Edema / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008577:Meningeal Neoplasms / Q000601:surgery*; D008579:Meningioma / Q000601:surgery*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology; D009381:Neoplasms, Radiation-Induced / Q000209:etiology; D011183:Postoperative Complications / Q000209:etiology*; D016634:Radiosurgery / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors