Chang S D, Levy R P, Adler J R, Martin D P, Krakovitz P R, Steinberg G K
Department of Neurosurgery, Stanford Stroke Center, Stanford University School of Medicine, California, USA.
Neurosurgery. 1998 Aug;43(2):213-20; discussion 220-1. doi: 10.1097/00006123-199808000-00011.
Radiosurgery is generally effective in obliterating true arteriovenous malformations, but less is known about its effects on angiographically occult vascular malformations (AOVMs). Since July 1983, 57 patients with surgically inaccessible AOVMs of the brain were treated using helium ion (47 patients) or linear accelerator (10 patients) radiosurgery. This study retrospectively evaluates the response of these AOVMs to treatment.
All patients presented with previous hemorrhage. The mean patient age was 35.6 years (range, 13-71 yr). The mean AOVM volume was 2.25 cm3 (range, 0.080-15.2 cm3), treated with a mean of 18.0 Gy equivalent (physical dose x relative biological effectiveness, which is 1.3 for helium ion Bragg peak) (range, 7.0-40 Gy equivalent). The Drake scale scores before treatment were as follows: excellent (25 patients), good (26 patients), and poor (6 patients). The mean follow-up period was 7.5 years (range, 9 mo-13.8 yr).
Eighteen patients (32%) bled symptomatically (20 hemorrhages) after radiosurgery. Sixteen hemorrhages occurred within 36 months after radiosurgery (9.4% annual bleed rate; 16 hemorrhages/171 patient yr); 4 hemorrhages occurred more than 36 months after treatment (1.6% annual bleed rate; 4 hemorrhages/257 patient yr) (P < 0.001). Complications included symptomatic radiation edema (four patients, 7%), necrosis (one patient, 2%), and increased seizure frequency (one patient, 2%). Eight patients underwent surgical resection of their AOVMs 8 to 59 months after radiosurgery because of subsequent hemorrhage. The Drake scale scores after treatment were as follows: excellent (25 patients), good (24 patients), poor (3 patients), and dead (5 patients, 3 of whom died as a result of causes unrelated to the AOVMs or radiosurgery).
Radiosurgery may be useful for AOVMs located in surgically inaccessible regions of the brain. A significant decrease in bleed rate exists more than 3 years after treatment compared with the bleed rate within 3 years of treatment. Because current neuroradiological techniques are not able to image obliterative response in these slow-flow vascular lesions, longer term clinical follow-up is required.
放射外科手术通常能有效消除真正的动静脉畸形，但对其对血管造影隐匿性血管畸形（AOVM）的影响了解较少。自1983年7月以来，57例脑部手术无法触及的AOVM患者接受了氦离子（47例）或直线加速器（10例）放射外科治疗。本研究回顾性评估了这些AOVM对治疗的反应。
所有患者既往均有出血史。患者平均年龄为35.6岁（范围13 - 71岁）。AOVM平均体积为2.25 cm³（范围0.080 - 15.2 cm³），平均接受18.0 Gy等效剂量治疗（物理剂量×相对生物效应，氦离子布拉格峰的相对生物效应为1.3）（范围7.0 - 40 Gy等效剂量）。治疗前德雷克量表评分如下：优（25例）、良（26例）、差（6例）。平均随访期为7.5年（范围9个月 - 13.8年）。
18例患者（32%）在放射外科治疗后出现有症状出血（20次出血）。16次出血发生在放射外科治疗后36个月内（年出血率9.4%；16次出血/171患者年）；4次出血发生在治疗后36个月以上（年出血率1.6%；4次出血/257患者年）（P < 0.001）。并发症包括有症状的放射性水肿（4例，7%）、坏死（1例，2%）和癫痫发作频率增加（1例，2%）。8例患者在放射外科治疗后8至59个月因随后出血接受了AOVM手术切除。治疗后德雷克量表评分如下：优（25例）、良（24例）、差（3例）、死亡（5例，其中3例死于与AOVM或放射外科无关的原因）。
放射外科手术可能对位于脑部手术无法触及区域的AOVM有用。与治疗后3年内的出血率相比，治疗3年后出血率显著降低。由于目前的神经放射学技术无法对这些慢血流血管病变的闭塞反应进行成像，因此需要更长时间的临床随访。
