{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,19]],"date-time":"2026-09-19T02:43:07Z","timestamp":1789785787536,"version":"4.0.1"},"reference-count":36,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"Supplement_1","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JNS"],"published-print":{"date-parts":[[2016,12]]},"abstract":"<jats:sec><jats:title>OBJECTIVE<\/jats:title><jats:p>The aim of this study was to reappraise long-term treatment outcomes of stereotactic radiosurgery (SRS) for vestibular schwannomas (VSs). The authors used a database that included patients who underwent SRS with a unique dose-planning technique, i.e., partial tumor coverage designed to avoid excess irradiation of the facial and cochlear nerves, focusing on tumor control and hearing preservation. Clinical factors associated with post-SRS tumor control and long-term hearing preservation were also analyzed.<\/jats:p><\/jats:sec><jats:sec><jats:title>METHODS<\/jats:title><jats:p>This institutional review board\u2013approved, retrospective cohort study used the authors' prospectively accumulated database. Among 207 patients who underwent Gamma Knife SRS for VSs between 1990 and 2005, 183 (who were followed up for at least 36 post-SRS months) were studied. The median tumor volume was 2.0 cm<jats:sup>3<\/jats:sup> (range 0.05\u201326.2 cm<jats:sup>3<\/jats:sup>). The median prescribed dose at the tumor periphery was 12.0 Gy (range 8.8\u201315.0 Gy; 12.0 Gy was used in 171 patients [93%]), whereas tumor portions facing the facial and cochlear nerves were irradiated with 10.0 Gy. As a result, 72%\u201399% of each tumor was irradiated with the prescribed dose. The mean cochlear doses ranged from 2.3 to 5.7 Gy (median 4.1 Gy).<\/jats:p><\/jats:sec><jats:sec><jats:title>RESULTS<\/jats:title><jats:p>The median durations of imaging and audiometric follow-up were 114 months (interquartile range 73\u2013144 months) and 59 months (interquartile range 33\u2013109 months), respectively. Tumor shrinkage was documented in 110 (61%), no change in 48 (27%), and enlargement in the other 22 (12%) patients. A further procedure (FP) was required in 15 (8%) patients. Thus, the tumor growth control rate was 88% and the clinical control rate (i.e., no need for an FP) was 92%. The cumulative FP-free rates were 96%, 93%, and 87% at the 60th, 120th, and 180th post-SRS month, respectively. Six (3%) patients experienced facial pain, and 2 developed transient facial palsy. Serviceable hearing was defined as a pure tone audiogram result better than 50 dB. Among the 66 patients with serviceable hearing before SRS who were followed up, hearing acuity was preserved in 23 (35%). Actuarial serviceable hearing preservation rates were 49%, 24%, and 12% at the 60th, 120th, and 180th post-SRS month, respectively. On univariable analysis, only cystic-type tumor (HR 3.36, 95% CI 1.18\u20139.36; p = 0.02) was shown to have a significantly unfavorable association with FP. Multivariable analysis followed by univariable analysis revealed that higher age (\u2265 65 years: HR 2.66, 95% CI 1.16\u20135.92; p = 0.02), larger tumor volume (\u2265 8 cm<jats:sup>3<\/jats:sup>: HR 5.36, 95% CI 1.20\u201317.4; p = 0.03), and higher cochlear dose (mean cochlear dose &gt; 4.2 Gy: HR 2.22, 95% CI 1.07\u20134.77; p = 0.03) were unfavorable factors for hearing preservation.<\/jats:p><\/jats:sec><jats:sec><jats:title>CONCLUSIONS<\/jats:title><jats:p>Stereotactic radiosurgery achieved good long-term results in this series. Tumor control was acceptable, and there were few serious complications in patients with small- to medium-sized VSs. Unfortunately, hearing preservation was not satisfactory. However, the longer the observation period, the more important it becomes to compare post-SRS hearing decreases with the natural decline in untreated cases.<\/jats:p><\/jats:sec>","DOI":"10.3171\/2016.7.gks161494","type":"journal-article","created":{"date-parts":[[2019,4,19]],"date-time":"2019-04-19T23:21:00Z","timestamp":1555716060000},"page":"64-72","source":"Crossref","is-referenced-by-count":96,"title":["Stereotactic radiosurgery for vestibular schwannomas: average 10-year follow-up results focusing on long-term hearing preservation"],"prefix":"10.3171","volume":"125","author":[{"given":"Shinya","family":"Watanabe","sequence":"first","affiliation":[{"name":"Katsuta Hospital Mito GammaHouse, Hitachi-naka;"},{"name":"Department of Neurosurgery, Mito Medical Center, Ibaraki-machi;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Masaaki","family":"Yamamoto","sequence":"additional","affiliation":[{"name":"Katsuta Hospital Mito GammaHouse, Hitachi-naka;"},{"name":"Department of Neurosurgery, Tokyo Women's Medical University Medical Center East, Tokyo;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takuya","family":"Kawabe","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Kyoto Prefectural University of Medicine Graduate School of Medical Sciences, Kyoto; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takao","family":"Koiso","sequence":"additional","affiliation":[{"name":"Katsuta Hospital Mito GammaHouse, Hitachi-naka;"},{"name":"Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tetsuya","family":"Yamamoto","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akira","family":"Matsumura","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hidetoshi","family":"Kasuya","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Tokyo Women's Medical University Medical Center East, Tokyo;"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1754","reference":[{"key":"b1-16-1494","series-title":"Int J Radiat Oncol Biol Phys","doi-asserted-by":"publisher","first-page":"329","DOI":"10.1016\/j.ijrobp.2012.05.003","article-title":"Symptomatic outcomes in relation to tumor expansion after fractionated stereotactic radiation therapy for vestibular schwannomas: single-institutional long-term experience","volume":"85","author":"Aoyama","year":"2013"},{"key":"b2-16-1494","series-title":"J 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