The Outcome of Hypofractionated Stereotactic Radiosurgery for Large Vestibular Schwannomas

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• 作者：Mario Teo¹ ; Michael Zhang¹ ; Amy Li¹ ; Patricia A. Thompson¹ ; Armine T. Tayag¹ ; Jonathan Wallach² ; Iris C. Gibbs² ; Scott G. Soltys² ; Steven L. Hancock² ; Steven D. Chang¹ ; ^{sdchang@stanford.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Cystic ; Facial nerve ; Hearing preservation ; Hypo-fractionated stereotactic radiosurgery ; Neurofibromatosis ; Primary treatment ; Vestibular schwannoma
• 刊名：World Neurosurgery
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：93
• 期：Complete
• 页码：398-409
• 全文大小：6730 K

文摘

Stereotactic radiosurgery (SRS) for large vestibular schwannomas (VS) remains controversial. We studied the tumor local control and toxicity rates after hypofractionated SRS for VS > 3 cm.

Methods

A total of 587 patients with VS treated with SRS between 1998 and 2014 were reviewed retrospectively, and 30 Koos grade IV VSs were identified. There were 6 patients with neurofibromatosis 2 (NF2), 8 with cystic tumors, 22 with solid tumors, 19 who underwent primary CyberKnife (CK), and 11 with >3 cm after previous resection. Patients were treated by a median of 3 fractions at 18 Gy.

Results

After a median 97 months, the 3- and 10-year Kaplan-Meier estimates of local control were 85% and 80%, respectively, with 20% requiring salvage treatment. For patients who had previous tumor resection rather than primary CK, the estimates were 46% and 5%, respectively, with progression, and 3-year control rates of 71% and 94% (P = 0.008). Tumor control was also lower among NF2 versus non-NF2 patients (40% vs. 95%; P = 0.0014). Among patients with good clinical baselines before CK, 88% were functionally independent (modified Rankin Scale score, 0–2), 88% had good facial function (House-Brackmann grade I–II), and 38% had serviceable hearing (Gardner-Robertson grade I–II) at last follow-up. Hearing worsening was more likely among patients treated with primary CK (33% vs. 90%; P = 0.04).

Conclusions

Overall, 80% of large VSs were adequately controlled by CK with 97 months of median follow-up. Patients with previous surgery and NF2 also appeared to have higher rates of tumor progression, and less favorable functional outcomes.