Nataf F, Meder J F, Oppenheim C, Merienne L, Schlienger M
Service de Neurochirurgie, Centre Hospitalier Sainte-Anne, 1, rue Cabanis, 75674 Paris Cedex 14, France.
Neurochirurgie. 2001 May;47(2-3 Pt 2):283-90.
Cerebral arteriovenous malformations surrounded by cerebrospinal fluid seemed to exhibit worse response to radiosurgery than others. We searched to verify if this is was true and to find causes.
and methods. From our series of 705 patients with cerebral arteriovenous malformations treated by radiosurgery, 3,8% (27/705) had choroidal or cisternal arteriovenous malformations. Revelation mode was hemorrhage in 86% of cases but sometimes headaches occurred before hemorrhage; thus overall hemorrhage rate was 96%. Mean age of revelation was 24. Mean size was 20 mm, mean volume was 4 cc. Spetzler & Martin's grades were 35% in grade II, 43% in grade III and 22% in grade IV. Location was ventricular in 63% of cases and cisternal in 37%. Mean dose at reference isodose was 24 Gy with a higher rate of monoisocenters. We looked for differences between this population of arteriovenous malformations and the rest of the series for patients, treatments prior radiosurgery, cerebral arteriovenous malformations's characteristics, dosimetric parameters and complications. Statistical analysis was done with a Pearson chi2 test and Spearman non parametric correlation test.
Obiteration rate was 47.6% with a mean delay of 26 months. Differential characteristics of choroidal or cisternal arteriovenous malformations were: younger age of revelation, higher frequency of hemorrhage, of intra or paranidal aneurysms, of deep unique drainage, a higher Spetzler grade and a smaller rate of complete recovering. Mortality and clinical morbidity due to radiosurgery were 0%. Actuarial rate of hemorrhage after radiosurgery was 4,34% per year and per patient or per hemorrhage. This rate was higher than in the global series. Parenchymal changes seen on MRI were less frequent (26,6%) and less serious (no grade 4 radionecrosis-like parenchymal changes).
Choroidal or cisternal arteriovenous malformations seem to respond less to radiosurgery than others. One potential explanation is the higher frequency of multiafferences of these arteriovenous malformations with anastomoses of anterior and posterior choroidal arteries. However, radiosurgery still stay a treatment of choice for these arteriovenous malformations with little adaptations of the irradiation strategy.
被脑脊液包围的脑动静脉畸形对放射外科治疗的反应似乎比其他畸形更差。我们进行研究以验证这是否属实并找出原因。
在我们接受放射外科治疗的705例脑动静脉畸形患者系列中，3.8%（27/705）患有脉络丛或脑池动静脉畸形。86%的病例以出血为首发表现，但有时在出血前会出现头痛；因此总体出血率为96%。首发时的平均年龄为24岁。平均大小为20毫米，平均体积为4立方厘米。斯佩茨勒和马丁分级中，II级占35%，III级占43%，IV级占22%。63%的病例位于脑室，37%位于脑池。参考等剂量线处的平均剂量为24 Gy，单中心治疗率较高。我们寻找了这组动静脉畸形患者与系列中其他患者之间在放射外科治疗前的治疗情况、脑动静脉畸形的特征、剂量学参数和并发症方面的差异。采用Pearson卡方检验和Spearman非参数相关检验进行统计分析。
闭塞率为47.6%，平均延迟时间为26个月。脉络丛或脑池动静脉畸形的不同特征为：首发年龄较小、出血频率较高、存在瘤内或瘤旁动脉瘤、深部单一引流、斯佩茨勒分级较高以及完全恢复率较低。放射外科治疗导致的死亡率和临床发病率为0%。放射外科治疗后每年每位患者或每次出血的精算出血率为4.34%。该比率高于总体系列。MRI上所见的实质改变较少见（26.6%）且程度较轻（无4级放射性坏死样实质改变）。
脉络丛或脑池动静脉畸形对放射外科治疗的反应似乎比其他畸形更差。一种可能的解释是这些动静脉畸形与脉络丛前、后动脉吻合的多支供血情况更为常见。然而，放射外科治疗仍是这些动静脉畸形的一种治疗选择，只需对照射策略稍作调整。
