title: Fractionated stereotactic radiotherapy in patients with optic nerve sheath meningioma.
abstract: OBJECTIVE
  To evaluate the effectiveness of fractionated stereotactic radiotherapy (SFRT) in the treatment of optic nerve sheath meningioma (ONSM).
  
  
  METHODS
  Between 1993 and 2005, 109 patients (113 eyes) with primary (n = 37) or secondary (n = 76) ONSM were treated according to a prospective protocol with SFRT to a median dose of 54 Gy. All patients underwent radiographic, ophthalmologic, and endocrine analysis before and after SFRT. Radiographic response, visual control, and late side effects were endpoints of the analysis.
  
  
  RESULTS
  Median time to last clinical, radiographic, and ophthalmologic follow up was 30.2 months (n = 113), 42.7 months (n = 108), and 53.7 months (n = 91), respectively. Regression of the tumor was observed in 5 eyes and progression in 4 eyes, whereas 104 remained stable. Visual acuity improved in 12, deteriorated in 11, and remained stable in 68 eyes. Mean visual field defects reduced from 33.6% (n = 90) to 17.8% (n = 56) in ipsilateral and from 10% (n = 94) to 6.7% (n = 62) in contralateral eyes. Ocular motility improved in 23, remained stable in 65, and deteriorated in 3 eyes. Radiographic tumor control was 100% at 3 years and 98% at 5 years. Visual acuity was preserved in 94.8% after 3 years and in 90.9% after 5 years. Endocrine function was normal in 90.8% after 3 years and in 81.3% after 5 years.
  
  
  CONCLUSIONS
  SFRT represents a highly effective treatment for ONSM. Interdisciplinary counseling of the patients is recommended. Because of the high rate of preservation of visual acuity we consider SFRT the standard approach for the treatment of ONSM. Prolonged observation is warranted to more accurately assess late visual impairment. Moderate de-escalation of the radiation dose might improve the preservation of visual acuity and pituitary gland function.
authors.affiliation: Department of Radiation Oncology, University of Tuebingen, Tuebingen, Germany. frank.paulsen@med.uni-tuebingen.de
authors.forename: Frank
authors.initials: F
authors.lastname: Paulsen
authors.forename: Stefan
authors.initials: S
authors.lastname: Doerr
authors.forename: Helmut
authors.initials: H
authors.lastname: Wilhelm
authors.forename: Gerd
authors.initials: G
authors.lastname: Becker
authors.forename: Michael
authors.initials: M
authors.lastname: Bamberg
authors.forename: Johannes
authors.initials: J
authors.lastname: Classen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D008579:Meningioma / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000209:etiology / Q000532:radiotherapy; D019574:Optic Nerve Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D010901:Pituitary Function Tests; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects / Q000379:methods; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods*; D012074:Remission Induction / Q000379:methods; D012189:Retrospective Studies; D047368:Tumor Burden; D014786:Vision Disorders / Q000209:etiology; D014792:Visual Acuity / Q000528:radiation effects; D055815:Young Adult