Departments of1Neurological Surgery and.
2Radiation Oncology, Columbia University Medical Center, New York, New York.
J Neurosurg. 2017 Dec;127(6):1231-1241. doi: 10.3171/2016.10.JNS161982. Epub 2017 Feb 10.
OBJECTIVE Advanced microsurgical techniques contribute to reduced morbidity and improved surgical management of meningiomas arising within the cerebellopontine angle (CPA). However, the goal of surgery has evolved to preserve the quality of the patient's life, even if it means leaving residual tumor. Concurrently, Gamma Knife radiosurgery (GKRS) has become an acceptable and effective treatment modality for newly diagnosed, recurrent, or progressive meningiomas of the CPA. The authors review their institutional experience with CPA meningiomas treated with GKRS, surgery, or a combination of surgery and GKRS. They specifically focus on rates of facial nerve preservation and characterize specific anatomical features of tumor location with respect to the internal auditory canal (IAC). METHODS Medical records of 76 patients with radiographic evidence or a postoperative diagnosis of CPA meningioma, treated by a single surgeon between 1992 and 2016, were retrospectively reviewed. Patients with CPA meningiomas smaller than 2.5 cm in greatest dimension were treated with GKRS, while patients with tumors 2.5 cm or larger underwent facial nerve-sparing microsurgical resection where appropriate. Various patient, clinical, and tumor data were gathered. Anatomical features of the tumor origin as seen on preoperative imaging confirmed by intraoperative investigation were evaluated for prognostic significance. Facial nerve preservation rates were evaluated. RESULTS According to our treatment paradigm, 51 (67.1%) patients underwent microsurgical resection and 25 (32.9%) patients underwent GKRS. Gross-total resection (GTR) was achieved in 34 (66.7%) patients, and subtotal resection (STR) in 17 (33.3%) patients. Tumors recurred in 12 (23.5%) patients initially treated surgically, requiring additional surgery and/or GKRS. Facial nerve function was unchanged or improved in 68 (89.5%) patients. Worsening facial nerve function occurred in 8 (10.5%) patients, all of whom had undergone microsurgical resection. Upfront treatment with GKRS for CPA meningiomas smaller than 2.5 cm was associated with preservation of facial nerve function in all patients over a median follow-up of 46 months, regardless of IAC invasion and tumor origin. Anatomical origin was associated with extent of resection but did not correlate with postoperative facial nerve function. Tumor size, extent of resection, and the presence of an arachnoid plane separating the tumor and the contents of the IAC were associated with postoperative facial nerve outcomes. CONCLUSIONS CPA meningiomas remain challenging lesions to treat, given their proximity to critical neurovascular structures. GKRS is a safe and effective option for managing CPA meningiomas smaller than 2.5 cm without associated mass effect or acute neurological symptoms. Maximal safe resection with preservation of neurological function can be performed for tumors 2.5 cm or larger without significant risk of facial nerve dysfunction, and, when combined with GKRS for recurrence and/or progression, provides excellent disease control. Anatomical features of the tumor origin offer critical insights for optimizing facial nerve preservation in this cohort.
先进的显微外科技术有助于降低发病率和改善桥小脑角(CPA)脑膜瘤的手术治疗。然而,手术的目标已经演变为保留患者的生活质量,即使这意味着留下残余肿瘤。同时,伽玛刀放射外科手术(GKRS)已成为治疗新诊断、复发性或进展性 CPA 脑膜瘤的一种可接受且有效的治疗方式。作者回顾了他们机构使用 GKRS、手术或手术联合 GKRS 治疗 CPA 脑膜瘤的经验。他们特别关注面神经保留率,并描述肿瘤位置与内听道(IAC)的特定解剖特征。
回顾性分析了 1992 年至 2016 年间,由同一位外科医生治疗的 76 例有影像学证据或术后诊断为 CPA 脑膜瘤的患者的病历。最大直径小于 2.5cm 的患者接受 GKRS 治疗,而肿瘤直径大于或等于 2.5cm 的患者则接受适当的面神经保留显微切除术。收集了各种患者、临床和肿瘤数据。评估术前影像学所见并经术中证实的肿瘤起源的解剖特征与预后的相关性。评估面神经保留率。
根据我们的治疗方案,51 例(67.1%)患者接受了显微切除术,25 例(32.9%)患者接受了 GKRS。34 例(66.7%)患者达到了全切除(GTR),17 例(33.3%)患者达到了次全切除(STR)。12 例(23.5%)最初接受手术治疗的患者肿瘤复发,需要再次手术和/或 GKRS。68 例(89.5%)患者面神经功能无变化或改善。8 例(10.5%)患者面神经功能恶化,均行显微切除术。对于最大直径小于 2.5cm 的 CPA 脑膜瘤, upfront 采用 GKRS 治疗,所有患者面神经功能均得到保留,中位随访时间为 46 个月,与 IAC 侵犯和肿瘤起源无关。肿瘤起源与切除程度有关,但与术后面神经功能无关。肿瘤大小、切除程度以及蛛网膜平面是否存在,将肿瘤与 IAC 内容物分隔开来,这些因素与术后面神经结果相关。
CPA 脑膜瘤仍然是具有挑战性的病变,因为它们靠近关键的神经血管结构。对于最大直径小于 2.5cm、无相关肿块效应或急性神经症状的 CPA 脑膜瘤,GKRS 是一种安全有效的治疗方法。对于直径为 2.5cm 或更大的肿瘤,可进行最大限度的安全切除并保留神经功能,且不会显著增加面神经功能障碍的风险,结合 GKRS 治疗复发和/或进展,可获得极好的疾病控制。肿瘤起源的解剖特征为优化面神经保护提供了关键的见解。