Introduction

Intraventricular trigonal meningiomas (ITM) seem to have a tendency for extensive perifocal edema formation following radiosurgery (RS). To further investigate this hypothesis, we undertook the following study.

Methods

We retrospectively reviewed records of patients who underwent RS for intraventricular meningiomas at our institution.

Results

From 1999 until 2019, 5 patients underwent single-session RS as primary treatment for ITM. Patients were treated either with a Gamma Knife or a CyberKnife. The mean prescription dose (PD) was 13.0 Gy ± 0.9, the mean tumor volume was 5.8 cc ± 3.1, and the mean follow-up (FU) was 8.9 years ± 5.6. Perifocal edema developed in 4/5 patients after a mean interval of 6.4 months ± 1.2. It was symptomatic in 2/5 patients. The edema regressed spontaneously in 4/5 patients. One of the patients underwent RS for the same ITM twice. One patient’s edema was treated medically with steroids, and none of the patients underwent surgery following RS.

Conclusion

Even though the number of patients is low, there seems to be a comparably high risk for the formation of a perifocal edema following RS for ITM. Single-session RS as primary treatment for ITM seems to be safe and effective even though a perifocal edema is likely to develop. The perifocal edema and the ensuing neurological deficits were transient and could be managed conservatively in all of our 5 cases.

中文翻译：

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脑室内脑膜瘤的前期放射外科手术后短暂性局灶性水肿的发生率很高。

介绍

脑室内三角脑膜瘤（ITM）似乎有放射外科手术（RS）后广泛的局灶性水肿形成的趋势。为了进一步研究该假设，我们进行了以下研究。

方法

我们回顾性回顾了在我们机构接受RS脑室内脑膜瘤治疗的患者的记录。

结果

从1999年到2019年，有5位患者接受了单次治疗RS作为ITM的主要治疗方法。用伽玛刀或电子刀治疗患者。平均处方剂量（PD）为13.0 Gy±0.9，平均肿瘤体积为5.8 cc±3.1，平均随访时间（FU）为8.9年±5.6。平均间隔为6.4个月±1.2后，有4/5例患者出现了周围性水肿。有2/5的患者有症状。4/5位患者水肿自发消退。其中一名患者接受了两次针对同一ITM的RS治疗。一名患者的水肿接受了类固醇药物治疗，RS术后均未进行任何手术。

结论

即使患者人数很少，RS for ITM后形成局灶性水肿的风险似乎也相对较高。尽管可能会发生局灶性水肿，但单次治疗RS作为ITM的主要治疗方法似乎是安全有效的。局灶性水肿和随之而来的神经功能缺损是短暂的，在我们所有的5例病例中都可以保守治疗。