Large vestibular schwannomas treated by Gamma Knife surgery: long-term outcomes
Large vestibular schwannomas treated by Gamma Knife surgery: long-term outcomes
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DOI：
10.3171/2010.8.gks10954
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发表时间：
2010-12-01
影响因子：
4.1
通讯作者：
Shih, Yang-Hsin
中科院分区：
文献类型：
--
作者：
Chung, Wen-Yuh;Pan, David Hung-Chi;Shih, Yang-Hsin
物体。虽然放射外科已被公认为治疗中小型前庭神经鞘瘤(VSS)的一种方法，但由于肿瘤肿胀和潜在的脑干压迫等不利影响，其在治疗大型VSS中的应用仍存在争议。作者报告了一项跨越17年的回顾研究，其中21例患者接受了伽玛刀手术(GKS)治疗大型VSS。报告长期结果，并分析影响肿瘤对GKS反应的可能因素。1993年3月至2009年10月，513名患有VSS的患者接受了GKS。较大的VS定义为直径<3厘米的肿瘤。本文对21例大VSS患者行GKS治疗，体积12.7~25.2 cm(3)，平均17.3 cm。其中14名患者之前曾接受过1次或1次以上的开颅手术以切除肿瘤。由于患者偏好或临床条件较差，不能在全身麻醉下进行显微手术，有7名患者单独接受了GKS。照射肿瘤的平均剂量为15~17.5Gy.肿瘤边缘照射剂量平均11.9Gy11~14Gy.平均随访期66个月(12~155个月)，中位随访期53个月。肿瘤控制率90.5%(21个病灶中19个)。面神经或三叉神经功能未见恶化。5例患者出现平衡障碍(部分为暂时性)。21名患者中有3名患者最初出现肿瘤肿胀，需要进行较小的手术干预，包括使用Ommaya储液罐进行抽吸或放置脑室-腹膜分流术。3例患者均在抽吸囊肿或脑室腹膜分流术后恢复满意。肿瘤控制与患者年龄、性别、肿瘤体积、放疗剂量、既往手术时间、脑干受压情况、岩骨侵犯、肿瘤与脑干T2信号比、有无囊肿者无明显相关性。然而，肿瘤与脑干的T2信号比与肿瘤肿胀的持续时间显著相关(p=0.003)。大型VSS的治疗对神经外科医生来说仍然是一个挑战，无论他们是进行显微手术还是放射外科手术。控制肿瘤生长和保护神经功能是治疗的主要目标。虽然2例(9.5%)需要延迟显微手术，但肿瘤控制率和面神经和三叉神经功能的良好保留率是放射外科的最大优势。放射外科不仅是治疗中小型VSS患者的一种实用方法，也是治疗长达25厘米的较大肿瘤的一种极好的工具。在某些病例中，放射外科在治疗大型VSS方面发挥了重要作用，取得了令人满意的结果。(DOI：10.3171/2010.8.GKS10954)
Object. Although radiosurgery has been well accepted as a treatment for small- to medium-sized vestibular schwannomas (VSs), its application in the treatment of large VSs remains controversial because of unfavorable effects such as tumor swelling and potential compression of the brainstem. The authors present a retrospective study spanning 17 years, during which 21 patients underwent Gamma Knife surgery (GKS) for large VSs. Long-term outcomes are reported, and possible factors affecting tumor responses to GKS are analyzed.Methods. Five hundred thirteen patients harboring VSs underwent GKS between March 1993 and October 2009. A large VS was defined as a tumor whose diameter was > 3 cm. This paper focuses on 21 patients who harbored large VSs ranging in volume from 12.7 to 25.2 cm(3) (mean 17.3 cm(3)) and were treated by GKS. Fourteen of these patients had undergone 1 or more craniotomies previously to remove the tumor. Seven patients underwent GKS alone because of patient preference or a poor clinical condition that precluded microsurgery with general anesthesia. The mean radiation dose directed to the tumor ranged from 15 to 17.5 Gy. The mean radiation dose prescribed to the tumor margin was 11.9 Gy (range 11-14 Gy). The mean follow-up period was 66 months (range 12-155 months), and the median follow-up period was 53 months.Results. The tumor control rate was 90.5% (19 of 21 lesions). No deterioration in facial nerve or trigeminal nerve function was noted. Disturbances in balance (some temporary) occurred in 5 patients. Three of the 21 patients developed initial tumor swelling, which required minor surgical interventions, including aspiration using an Ommaya reservoir or placement of a ventriculoperitoneal shunt. All 3 patients recovered satisfactorily after aspiration of an enlarging cyst or ventriculoperitoneal shunt placement. There was no significant correlation between tumor control and the following factors: patient age or sex, tumor volume, radiation dose, previous operation, presence of brainstem compression, petrous bone invasion, T2 signal ratio between tumor and brainstem, and presence of a cyst. However, there was a significant correlation between the T2 signal ratio between tumor and brainstem and the duration of tumor swelling (p = 0.003).Conclusions. Treatment of large VSs remains a challenge to neurosurgeons regardless of whether they perform microsurgery or radiosurgery. Control of tumor growth and preservation of neurological function are the main goals of treatment. Although delayed microsurgery was required in 2 patients (9.5%), the satisfactory tumor control rate and excellent preservation of facial and trigeminal nerve function are the great advantages of radiosurgery. Radiosurgery is not only a practical treatment for patients with small- to medium-sized VSs, but it is also an excellent tool for treating larger tumors up to 25 cm(3). In selected cases, radiosurgery plays an important role in treating large VSs with satisfactory results. (DOI: 10.3171/2010.8.GKS10954)