title: Benign orbital apex tumors treated with multisession gamma knife radiosurgery.
abstract: OBJECTIVE
  The orbital apex is an important anatomic landmark that hosts numerous critical neurovascular structures. Tumor resection performed at this complex region poses a therapeutic challenge to orbital surgeons and often is associated with significant visual morbidity. This article reports the efficacy and safety of multisession gamma knife radiosurgery (GKRS) in benign, well-circumscribed tumors located at the orbital apex.
  
  
  METHODS
  Retrospective interventional case series.
  
  
  METHODS
  Five patients with visual disturbances resulting from a benign, well-circumscribed orbital apex tumor (3 cases of cavernous hemangioma and 2 cases of schwannoma).
  
  
  METHODS
  Each patient treated with GKRS with a total radiation dose of 20 Gy in 4 sessions (5 Gy in each session with an isodose line of 50%) delivered to the tumor margin.
  
  
  METHODS
  Best-corrected visual acuity, visual field changes, orbital imaging, tumor growth control, and side effects of radiation.
  
  
  RESULTS
  All patients demonstrated improvement in visual acuity, pupillary responses, color vision, and visual field. Tumor shrinkage was observed in all patients and remained stable until the last follow-up. No adverse events were noted during or after the radiosurgery. None of the patients experienced any radiation-related ocular morbidity.
  
  
  CONCLUSIONS
  From this experience, multisession GKRS seems to be an effective management strategy to treat solitary, benign, well-circumscribed orbital apex tumors.
authors.affiliation: Department of Ophthalmology, Hospital Serdang, Kuala Lumpur, Malaysia.
authors.forename: Alice Siew Ching
authors.initials: ASC
authors.lastname: Goh
authors.affiliation: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Electronic address: ydkimoph@skku.edu.
authors.forename: Yoon-Duck
authors.initials: YD
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kyung In
authors.initials: KI
authors.lastname: Woo
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jung-Il
authors.initials: JI
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006392:Hemangioma, Cavernous / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008297:Male; D009442:Neurilemmoma / Q000473:pathology / Q000601:surgery*; D009918:Orbital Neoplasms / Q000473:pathology / Q000601:surgery*; D016634:Radiosurgery; D019233:Retreatment; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology