Friedman William A, Bova Frank J
Department of Neurological Surgery, University of Florida, Gainesville, FL 32610, USA.
Neurol Res. 2011 Oct;33(8):803-19. doi: 10.1179/1743132811Y.0000000043.
Stereotactic radiosurgery is the term coined by Lars Leksell to describe the application of a single, high dose of radiation to a stereotactically defined target volume. In the 1970s, reports began to appear documenting the successful obliteration of arteriovenous malformations (AVMs) with radiosurgery. When an AVM is treated with radiosurgery, a pathologic process appears to be induced that is similar to the response-to-injury model of atherosclerosis. Radiation injury to the vascular endothelium is believed to induce the proliferation of smooth-muscle cells and the elaboration of extracellular collagen, which leads to progressive stenosis and obliteration of the AVM nidus thereby eliminating the risk of hemorrhage. The advantages of radiosurgery - compared to microsurgical and endovascular treatments - are that it is noninvasive, has minimal risk of acute complications, and is performed as an outpatient procedure requiring no recovery time for the patient. The primary disadvantage of radiosurgery is that cure is not immediate. While thrombosis of the lesion is achieved in the majority of cases, it commonly does not occur until two or three years after treatment. During the interval between radiosurgical treatment and AVM thrombosis, the risk of hemorrhage remains. Another potential disadvantage of radiosurgery is possible long term adverse effects of radiation. Finally, radiosurgery has been shown to be less effective for lesions over 10 cc in volume. For these reasons, selection of the optimal treatment for an AVM is a complex decision requiring the input of experts in endovascular, open surgical, and radiosurgical treatment. In the pages below, we will review the world's literature on radiosurgery for AVMs. Topics reviewed will include the following: radiosurgical technique, radiosurgery results (gamma knife radiosurgery, particle beam radiosurgery, linear accelerator radiosurgery), hemorrhage after radiosurgery, radiation induced complications, repeat radiosurgery, and radiosurgery for other types of vascular malformation.
立体定向放射外科是拉尔斯·莱克塞尔创造的术语，用于描述将单次高剂量辐射应用于立体定向定义的靶体积。20世纪70年代，开始出现报告记录用放射外科成功消除动静脉畸形（AVM）。当用放射外科治疗AVM时，似乎会引发一种病理过程，类似于动脉粥样硬化的损伤反应模型。血管内皮的辐射损伤被认为会诱导平滑肌细胞增殖和细胞外胶原蛋白的形成，从而导致AVM病灶逐渐狭窄和闭塞，进而消除出血风险。与显微外科和血管内治疗相比，放射外科的优点是无创、急性并发症风险极小，并且作为门诊手术进行，患者无需恢复时间。放射外科的主要缺点是不能立即治愈。虽然在大多数情况下病变会形成血栓，但通常要在治疗后两三年才会发生。在放射外科治疗和AVM血栓形成的间隔期间，出血风险仍然存在。放射外科的另一个潜在缺点是可能存在辐射的长期不良影响。最后，已证明放射外科对体积超过10立方厘米的病变效果较差。由于这些原因，为AVM选择最佳治疗方法是一个复杂的决定，需要血管内、开放手术和放射外科治疗方面的专家参与。在以下篇幅中，我们将回顾世界上关于AVM放射外科的文献。回顾的主题将包括以下内容：放射外科技术、放射外科结果（伽玛刀放射外科、粒子束放射外科、直线加速器放射外科）、放射外科后出血、辐射引起的并发症、重复放射外科以及其他类型血管畸形的放射外科治疗。
