title: Gamma knife radiosurgery for glomus jugulare and tympanicum.
abstract: OBJECTIVE
  To establish the role of gamma knife radiosurgery (GKS) as a treatment strategy for glomus jugulare and tympanicum.
  
  
  METHODS
  A retrospective review of 14 glomus tumors, including 11 glomus jugulare and 3 glomus tympanicum tumors, which were treated by GKS in Taipei Veterans General Hospital from 1993 to 2009, was conducted. Two of these cases had undergone prior surgery with partial tumor resection, and the other 12 cases received primary treatment with GKS after a thorough neuroimaging and cerebral angiography. The tumor volume ranged from 6.5 to 22.1 ml. The maximum dose at the tumor center ranged from 21.6 to 26.3 Gy. All 14 patients were regularly followed up by clinical and radiological evaluations. The median follow-up time was 40.3 months.
  
  
  RESULTS
  All 14 patients had significant tumor regression after radiosurgery. The median tumor volume reduction was 34.0% (range 3-79%). Only 1 patient had temporary tumor volume progression (24% increment 6 months post-treatment), accompanied with unilateral facial palsy (from grade III to grade IV) and hearing impairment (from grade I to grade II). The tumor volume of this patient had regressed by 12 months, but facial palsy persisted. The tumor control rate in the series was 100% (n = 14/14), and the preservation rate of cranial nerve function was 92.8% (13/14). There was no complication of lower cranial nerve damage after radiosurgery.
  
  
  CONCLUSIONS
  GKS appeared to be a good alternative or adjuvant to microsurgical resection in patients who are not amenable to complete surgical eradication, with an excellent tumor control rate and little morbidity after long-term follow-up.
authors.affiliation: Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
authors.forename: Cheng-Chia
authors.initials: CC
authors.lastname: Lee
authors.forename: David Hung-Chi
authors.initials: DH
authors.lastname: Pan
authors.forename: Jau-Ching
authors.initials: JC
authors.lastname: Wu
authors.forename: Wen-Yuh
authors.initials: WY
authors.lastname: Chung
authors.forename: Hsiu-Mei
authors.initials: HM
authors.lastname: Wu
authors.forename: Huai-Che
authors.initials: HC
authors.lastname: Yang
authors.forename: Kang-Du
authors.initials: KD
authors.lastname: Liu
authors.forename: Wan-Yuo
authors.initials: WY
authors.lastname: Guo
authors.forename: Yang-Hsin
authors.initials: YH
authors.lastname: Shih
mesh_terms: D000328:Adult; D000368:Aged; D004428:Ear Neoplasms / Q000175:diagnosis / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D005925:Glomus Jugulare Tumor / Q000175:diagnosis / Q000601:surgery*; D043604:Glomus Tympanicum Tumor / Q000175:diagnosis / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D055815:Young Adult