Klijn Stijn, Verheul Jeroen B, Beute Guus N, Leenstra Sieger, Mulder Jef J S, Kunst Henricus P M, Hanssens Patrick E J
Gamma Knife Center Tilburg, St. Elisabeth Hospital, Tilburg;
Department of Neurosurgery, Erasmus Medical Center, Rotterdam; and.
J Neurosurg. 2016 Jun;124(6):1619-26. doi: 10.3171/2015.4.JNS142415. Epub 2015 Oct 2.
OBJECT The authors of this study sought to assess tumor control and complication rates in a large cohort of patients who underwent Gamma Knife radiosurgery (GKRS) for vestibular schwannoma (VS) and to identify predictors of tumor control. METHODS The records of 420 patients treated with GKRS for VS with a median marginal dose of 11 Gy were retrospectively analyzed. Patients with neurofibromatosis Type 2 or who had undergone treatment for VS previously were excluded. The authors assessed tumor control and complication rates with chart review and used the Cox proportional hazards model to identify predictors of tumor control. Preservation of serviceable hearing, defined as Gardner-Robertson Class I-II, was evaluated in a subgroup of 71 patients with serviceable hearing at baseline and with available follow-up audiograms. RESULTS The median VS tumor volume was 1.4 cm(3), and the median length of follow-up was 5.1 years. Actuarial 5-and 10-year tumor control rates were 91.3% and 84.8%, respectively. Only tumor volume was a statistically significant predictor of tumor control rate. The tumor control rate decreased from 94.1% for tumors smaller than 0.5 cm(3) to 80.7% for tumors larger than 6 cm(3). Thirteen patients (3.1%) had new or increased permanent trigeminal nerve neuropathy, 4 (1.0%) had new or increased permanent facial weakness, and 5 (1.2%) exhibited new or increased hydrocephalus requiring a shunting procedure. Actuarial 3-year and 5-year hearing preservation rates were 65% and 42%, respectively. CONCLUSIONS The 5-year actuarial tumor control rate of 91.3% in this cohort of patients with VS compared slightly unfavorably with the rates reported in other large studies, but the complication and hearing preservation rates in this study were similar to those reported previously. Various factors may contribute to the observed differences in reported outcomes. These factors include variations in treatment indication and in the definition of treatment failure, as well as a lack of standardization of terminology and of evaluation of complications. Last, differences in dosimetric variables may also be an explanatory factor.
目的 本研究的作者旨在评估接受伽玛刀放射外科治疗（GKRS）的大量前庭神经鞘瘤（VS）患者的肿瘤控制情况和并发症发生率，并确定肿瘤控制的预测因素。方法 回顾性分析420例接受GKRS治疗VS且中位边缘剂量为11 Gy的患者记录。排除患有2型神经纤维瘤病或既往接受过VS治疗的患者。作者通过病历审查评估肿瘤控制情况和并发症发生率，并使用Cox比例风险模型确定肿瘤控制的预测因素。在71例基线时有可用听力且有随访听力图的有实用听力的患者亚组中，评估了定义为Gardner-Robertson I-II级的实用听力的保留情况。结果 VS肿瘤体积中位数为1.4 cm³，中位随访时间为5.1年。5年和10年的精算肿瘤控制率分别为91.3%和84.8%。只有肿瘤体积是肿瘤控制率的统计学显著预测因素。肿瘤体积小于0.5 cm³的患者肿瘤控制率为94.1%，而肿瘤体积大于6 cm³的患者肿瘤控制率降至80.7%。13例患者（3.1%）出现新的或加重的永久性三叉神经病变，4例（1.0%）出现新的或加重的永久性面部无力，5例（1.2%）出现新的或加重的脑积水，需要进行分流手术。3年和5年的精算听力保留率分别为65%和42%。结论 该组VS患者5年精算肿瘤控制率为91.3%，与其他大型研究报告的比率相比略低，但本研究中的并发症和听力保留率与先前报告的相似。各种因素可能导致报告结果的差异。这些因素包括治疗指征和治疗失败定义的差异，以及术语标准化和并发症评估的缺乏。最后，剂量学变量的差异也可能是一个解释因素。
