BACKGROUND Facial nerve schwannomas are rare, challenging tumors to manage due to their nerve of origin. Functional outcomes after stereotactic radiosurgery (SRS) are incompletely defined. OBJECTIVE To analyze the effect of facial nerve segment involvement on functional outcome for these tumors. METHODS Patients who underwent single-session SRS for facial nerve schwannomas with at least 3 mo follow-up at 11 participating centers were included. Preoperative and treatment variables were recorded. Outcome measures included radiological tumor response and neurological function. RESULTS A total of 63 patients (34 females) were included in the present study. In total, 75% had preoperative facial weakness. Mean tumor volume and margin dose were 2.0 ± 2.4 cm3 and 12.2 ± 0.54 Gy, respectively. Mean radiological follow-up was 45.5 ± 38.9 mo. Progression-free survival at 2, 5, and 10 yr was 98.1%, 87.2%, and 87.2%, respectively. The cumulative proportion of patients with regressing tumors at 2, 5, and 10 yr was 43.1%, 63.6%, and 63.6%, respectively. The number of involved facial nerve segments significantly predicted tumor progression (P = .04). Facial nerve function was stable or improved in 57 patients (90%). Patients with involvement of the labyrinthine segment of the facial nerve were significantly more likely to have an improvement in facial nerve function after SRS (P = .03). Hearing worsened in at least 6% of patients. Otherwise, adverse radiation effects included facial twitching (3 patients), facial numbness (2 patients), and dizziness (2 patients). CONCLUSION SRS for facial nerve schwannomas is effective and spares facial nerve function in most patients. Some patients may have functional improvement after treatment, particularly if the labyrinthine segment is involved.

中文翻译：

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解剖节段参与对面神经神经鞘瘤立体定向放射外科手术的影响：一项国际多中心队列研究

背景技术面神经鞘瘤是罕见的，由于其起源神经而难以治疗的肿瘤。立体定向放射外科 (SRS) 后的功能结果尚未完全确定。目的分析面神经节段受累对这些肿瘤功能预后的影响。方法 纳入在 11 个参与中心接受至少 3 个月随访的面神经神经鞘瘤单次 SRS 的患者。记录术前和治疗变量。结果测量包括放射肿瘤反应和神经功能。结果 本研究共纳入 63 名患者（34 名女性）。总共有 75% 有术前面部无力。平均肿瘤体积和边缘剂量分别为 2.0 ± 2.4 cm3 和 12.2 ± 0.54 Gy。平均放射学随访时间为 45.5 ± 38.9 个月。2、5 和 10 年的无进展生存率分别为 98.1%、87.2% 和 87.2%。在第 2、5 和 10 年时肿瘤消退的患者累积比例分别为 43.1%、63.6% 和 63.6%。受累面神经节段的数量显着预测肿瘤进展（P = .04）。57 名患者（90%）面神经功能稳定或改善。面神经迷路段受累的患者在 SRS 后面神经功能明显改善的可能性更大 (P = .03)。至少 6% 的患者听力恶化。否则，不良辐射效应包括面部抽搐（3 名患者）、面部麻木（2 名患者）和头晕（2 名患者）。结论 SRS 治疗面神经神经鞘瘤是有效的，并且在大多数患者中保留了面神经功能。