title: Gamma Knife radiosurgery following subtotal resection of vestibular schwannoma.
abstract: During treatment of large vestibular schwannomas, incomplete resection (IR) followed by Gamma Knife surgery (GKS; Elekta AB, Stockholm, Sweden) possibly offers tumor growth control and good clinical outcome, and is being discussed as an alternative to complete tumor removal with its inherent risks, especially for facial nerve function. However, available data for this concept are limited due to the small number of published studies. To analyze the effects of combined therapy in a larger cohort, we reviewed the currently available data. Six studies comprising 159 patients with a tumor diameter of at least 2 cm were included (median volume 19.95 cm(3) in four studies, n=137). GKS was performed on average 6 months postoperatively with a mean marginal dose of 11.88 Gy (mean target volume 4.42 cm(3), mean diameter 18.45 mm). Preoperatively facial nerve function was serviceable (House and Brackmann Grades I+II) in 158 of 159 patients (99.4%) and in 125 of 151 patients (82.8%, 95% confidence interval [CI] 76-88%) postoperatively. Hearing was serviceable in 29 of 151 patients (19.2%) preoperatively and in 16 of 79 patients postoperatively (20.2%, 95%CI 12-31%). Within a mean follow-up time of 50 months (range 12-102 months), facial nerve function and hearing after IR remained serviceable in 142 of 151 (94.0%, 95%CI 89-97%) and 15 of 129 patients (11.6%, 95%CI 7-18%). Tumor growth control was achieved in 149 of 159 patients (93.8%). Six patients were subjected to repeated therapy. Minimal complications were reported for microsurgery and GKS. Combined therapy was shown to be beneficial regarding both tumor control and adverse side effects among all analyzed studies.
authors: Department of Neurosurgery, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Münster, Germany. Electronic address: benjamin.brokinkel@ukmuenster.de.
authors: Benjamin
authors: B
authors: Brokinkel
authors: Institute of Biostatistics and Clinical Research, University Hospital Münster, Münster, Germany.
authors: Cristina
authors: C
authors: Sauerland
authors: Department of Neurosurgery, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Münster, Germany.
authors: Markus
authors: M
authors: Holling
authors: Department of Neurosurgery, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Münster, Germany.
authors: Christian
authors: C
authors: Ewelt
authors: Gamma Knife Center Krefeld, Krefeld, Germany.
authors: Gerhard
authors: G
authors: Horstmann
authors: Gamma Knife Center Krefeld, Krefeld, Germany.
authors: Albertus T C J
authors: AT
authors: van Eck
authors: Department of Neurosurgery, University Hospital Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Münster, Germany.
authors: Walter
authors: W
authors: Stummer
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000601:surgery*; D039781:PubMed; D016634:Radiosurgery / Q000379:methods*
keywords: Acoustic neuroma; Cerebellopontine angle tumor; Gamma Knife radiosurgery; Microsurgery; Operative surgical procedures; Vestibular schwannoma