{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T12:09:39Z","timestamp":1791374979966,"version":"4.3.1"},"reference-count":53,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"3","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JNS"],"published-print":{"date-parts":[[2013,3]]},"abstract":"\nObject<\/jats:title>\nLittle is known about long-term outcomes, including tumor control and adverse radiation effects, in patients harboring vestibular schwannomas (VSs) treated with stereotactic radiosurgery > 10 years previously. The aim of this study was to confirm whether Gamma Knife surgery (GKS) for VSs continues to be safe and effective > 10 years after treatment.<\/jats:p><\/jats:sec>\n\nMethods<\/jats:title>\nA total of 440 patients with VS (including neurofibromatosis Type 2) treated with GKS between May 1991 and December 2000 were evaluable. Of these, 347 patients (79%) underwent GKS as an initial treatment and 93 (21%) had undergone prior resection. Three hundred fifty-eight patients (81%) had a solid tumor and 82 (19%) had a cystic tumor. The median tumor volume was 2.8 cm3<\/jats:sup> and the median marginal dose was 12.8 Gy.<\/jats:p><\/jats:sec>\n\nResults<\/jats:title>\nThe median follow-up period was 12.5 years. The actuarial 5- and \u2265 10-year progression-free survival was 93% and 92%, respectively. No patient developed treatment failure > 10 years after treatment. According to multivariate analysis, significant factors related to worse progression-free survival included brainstem compression with a deviation of the fourth ventricle (p < 0.0001), marginal dose \u2264 13 Gy (p = 0.01), prior treatment (p = 0.02), and female sex (p = 0.02). Of 287 patients treated at a recent optimum dose of \u2264 13 Gy, 3 (1%) developed facial palsy, including 2 with transient palsy and 1 with persistent palsy after a second GKS, and 3 (1%) developed facial numbness, including 2 with transient and 1 with persistent facial numbness. The actuarial 10-year facial nerve preservation rate was 97% in the high marginal dose group (> 13 Gy) and 100% in the low marginal dose group (\u2264 13 Gy). Ten patients (2.3%) developed delayed cyst formation. One patient alone developed malignant transformation, indicating an incidence of 0.3%.<\/jats:p><\/jats:sec>\n\nConclusions<\/jats:title>\nIn this study GKS was a safe and effective treatment for the majority of patients followed > 10 years after treatment. Special attention should be paid to cyst formation and malignant transformation as late adverse radiation effects, although they appeared to be rare. However, it is necessary to collect further long-term follow-up data before making conclusions about the long-term safety and efficacy of GKS, especially for young patients with VSs.<\/jats:p><\/jats:sec>","DOI":"10.3171\/2012.10.jns12523","type":"journal-article","created":{"date-parts":[[2012,11,9]],"date-time":"2012-11-09T15:04:00Z","timestamp":1352473440000},"page":"557-565","source":"Crossref","is-referenced-by-count":221,"title":["Long-term safety and efficacy of stereotactic radiosurgery for vestibular schwannomas: evaluation of 440 patients more than 10 years after treatment with Gamma Knife surgery"],"prefix":"10.3171","volume":"118","author":[{"given":"Toshinori","family":"Hasegawa","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yoshihisa","family":"Kida","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takenori","family":"Kato","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hiroshi","family":"Iizuka","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shunichiro","family":"Kuramitsu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takashi","family":"Yamamoto","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1754","reference":[{"key":"b1-jns12523","series-title":"World Neurosurg","doi-asserted-by":"publisher","first-page":"751","DOI":"10.1016\/j.wneu.2010.04.009","article-title":"Malignant peripheral nerve sheath tumor arising from benign vestibular schwannoma treated by gamma knife radiosurgery after two previous surgeries: a case report with surgical and pathological observations","volume":"73","author":"Akamatsu","year":"2010"},{"key":"b2-jns12523","series-title":"Br J Neurosurg","doi-asserted-by":"publisher","first-page":"284","DOI":"10.1080\/02688690220148888","article-title":"Malignancy in a vestibular schwannoma. 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