title: Long-term results of Leksell gamma knife surgery for trigeminal schwannomas.
abstract: OBJECTIVE
  The authors evaluated the long-term efficacy of gamma knife surgery (GKS) in patients with trigeminal schwannomas.
  
  
  METHODS
  Fifty-six patients, 31 women and 25 men (mean age 42 years), underwent GKS for trigeminal schwannomas. Fourteen had previously undergone surgery, and GKS was the primary treatment in the remaining 42 patients. The mean target volume was 8.7 cm3 (range 0.8-33 cm3); the mean maximum dose was 27 Gy (range 20-40 Gy); the mean tumor margin dose was 13.3 Gy (range 10-15 Gy); and the mean follow-up period was 68 months (range 27-114 months). Disappearance of the tumor occurred in seven patients. An obvious decrease in tumor volume was observed in 41 patients, four tumors remained unchanged, and four tumors progressed at 5, 26, 30, and 60 months, respectively. One patient with disease progression died of tumor progression at 36 months after GKS. The tumor growth control rate in this group was 93% (52 of 56 cases). Mild numbness or diplopia was relieved completely in 14 patients. Improvement of other neurological deficits was demonstrated in 25 patients. Trigeminal nerve dysfunction was either unchanged or slightly worse in 13 patients after GKS. Four patients experienced mild symptom deterioration related to tumor progression.
  
  
  CONCLUSIONS
  Radiosurgery proved to be an effective treatment for small- and medium-sized trigeminal schwannomas. Some larger tumors are also suitable for radiosurgery if there is no significant brainstem compression.
authors.affiliation: Department of Neurosurgery and Radiology, Huashan Hospital and Shanghai Gamma Knife Hospital, Fudan University, Shanghai Neurosurgical Center, Shanghai, China.
authors.forename: Li
authors.initials: L
authors.lastname: Pan
authors.forename: En-Min
authors.initials: EM
authors.lastname: Wang
authors.forename: Nan
authors.initials: N
authors.lastname: Zhang
authors.forename: Liang-Fu
authors.initials: LF
authors.lastname: Zhou
authors.forename: Bing-Jiang
authors.initials: BJ
authors.lastname: Wang
authors.forename: Ya-Fei
authors.initials: YF
authors.lastname: Dong
authors.forename: Jia-Zhong
authors.initials: JZ
authors.lastname: Dai
authors.forename: Pei-Wu
authors.initials: PW
authors.lastname: Cai
mesh_terms: D020434:Abducens Nerve Diseases / Q000209:etiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D001927:Brain Diseases / Q000209:etiology; D002648:Child; D003390:Cranial Nerve Neoplasms / Q000473:pathology / Q000601:surgery*; D003560:Cysts / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000473:pathology / Q000601:surgery*; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000150:complications; D016634:Radiosurgery / Q000295:instrumentation*; D013995:Time; D014276:Trigeminal Nerve / Q000473:pathology / Q000601:surgery*