title: Tumor control and hearing preservation after Gamma Knife radiosurgery for vestibular schwannomas in neurofibromatosis type 2.
abstract: To analyze the effect of Gamma Knife radiosurgery (GKS) on tumor control and hearing preservation rates in patients with vestibular schwannomas (VS) in a setting of neurofibromatosis type 2 (NF 2), a retrospective study was carried out at a tertiary-level referral Gamma Knife unit. Dose plans, pre- and postoperative radiology, and follow-up clinical records of patients with NF 2 who had undergone GKS for VS using a Leksell Gamma Knife (Elekta Instruments AB, Stockholm, Sweden) model B unit from 1997 to 2008 were reviewed. Thirty patients with 54 VS underwent GKS. The average age of the cohort was 29 years (range 10-56 years). Twenty-four patients had bilateral VS. The commonest clinical presentation was hearing loss and tinnitus. Primary GKS was given to 36 tumors, while 18 tumors received it as an adjunct to surgery. Average tumor size was 3.7 cc (range 0.1-13.3 cc). A median 12 Gy prescription dose (range 10-15 Gy) was administered at the 50% isodose (range 42-50%) to cover on average 91.5% of the tumor. Eighteen patients were available for clinical, 14 patients for radiological, and 5 patients (with useful hearing) for audiometric follow-up at an average of 26.6 months. The tumor control rate was 87.5% in this series (33.3% tumor regression), while hearing preservation was noted in 66.7% of cases. One patient developed worsening of facial function. GKS for VS provides satisfactory tumor control and hearing preservation in patients with NF 2. Long-term follow-up will determine future recommendations.
authors.affiliation: Department of Neurosurgery and Gamma Knife, All India Institute of Medical Sciences, New Delhi, 110029, India. manishsinghsharma@gmail.com
authors.forename: Manish Singh
authors.initials: MS
authors.lastname: Sharma
authors.forename: Rakesh
authors.initials: R
authors.lastname: Singh
authors.forename: Shashank S
authors.initials: SS
authors.lastname: Kale
authors.forename: Deepak
authors.initials: D
authors.lastname: Agrawal
authors.forename: Bhawani Shankar
authors.initials: BS
authors.lastname: Sharma
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Mahapatra
mesh_terms: D000293:Adolescent; D000328:Adult; D001299:Audiometry / Q000379:methods; D002648:Child; D005260:Female; D006309:Hearing / Q000502:physiology* / Q000528:radiation effects; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016518:Neurofibromatosis 2 / Q000601:surgery*; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
references.citation: Br J Neurosurg. 2002 Jun;16(3):284-9
references.pmid: 12201399
references.citation: JAMA. 1997 Jul 2;278(1):51-7
references.pmid: 9207339
references.citation: Cancer. 2009 Jan 15;115(2):390-8
references.pmid: 19109818
references.citation: Neurosurgery. 2006 Jul;59(1):77-85; discussion 77-85
references.pmid: 16823303
references.citation: J Neurol Neurosurg Psychiatry. 2003 Sep;74(9):1288-93
references.pmid: 12933938
references.citation: J Neurosurg. 2005 Jan;102 Suppl:195-9
references.pmid: 15662809
references.citation: Neuro Oncol. 2007 Oct;9(4):447-53
references.pmid: 17704364
references.citation: J Med Genet. 1992 Dec;29(12):841-6
references.pmid: 1479598
references.citation: Neurology. 2000 Jan 11;54(1):71-6
references.pmid: 10636128
references.citation: Arch Neurol. 1988 May;45(5):575-8
references.pmid: 3128965
references.citation: Surg Neurol. 2000 Apr;53(4):383-89; discussion 389-90
references.pmid: 10825525
references.citation: ASHA. 1981 Jul;23(7):493-500
references.pmid: 7052898
references.citation: Neurosurgery. 2005 Aug;57(2):257-65; discussion 257-65
references.pmid: 16094154
references.citation: Int J Radiat Oncol Biol Phys. 2003 Dec 1;57(5):1450-9
references.pmid: 14630285
references.citation: No Shinkei Geka. 1995 Feb;23(2):131-5
references.pmid: 7877733
references.citation: Br J Neurosurg. 2005 Feb;19(1):5-12
references.pmid: 16147576
references.citation: Neurochirurgie. 2000 Sep;46(4):339-53; discussion 354
references.pmid: 11015671
references.citation: Int J Radiat Oncol Biol Phys. 2007 Jul 1;68(3):845-51
references.pmid: 17379451
references.citation: Neurosurgery. 1997 Apr;40(4):696-705; discussion 705-6
references.pmid: 9092842
references.citation: Neurosurgery. 2007 Mar;60(3):460-8; discussion 468-70
references.pmid: 17327790