Departments of Neurological Surgery and.
J Neurosurg. 2014 Mar;120(3):583-90. doi: 10.3171/2013.9.JNS131022. Epub 2013 Oct 25.
Arteriovenous malformations (AVMs) of the posterior fossa have an aggressive natural history and propensity for hemorrhage. Although the cerebellum accounts for the majority of the posterior fossa volume, there is a paucity of stereotactic radiosurgery (SRS) outcome data for AVMs of this region. The authors sought to evaluate the long-term outcomes and risks of cerebellar AVM radiosurgery.
This single-institution retrospective analysis reviewed the authors' experience with Gamma Knife surgery during the period 1987-2007. During this time 64 patients (median age 47 years, range 8-75 years) underwent SRS for a cerebellar AVM. Forty-seven patients (73%) presented with an intracranial hemorrhage. The median target volume was 3.85 cm(3) (range 0.2-12.5 cm(3)), and the median marginal dose was 21 Gy (range 15-25 Gy).
Arteriovenous malformation obliteration was confirmed by MRI or angiography in 40 patients at a median follow-up of 73 months (range 4-255 months). The actuarial rates of total obliteration were 53% at 3 years, 69% at 4 years, and 76% at 5 and 10 years. Elevated obliteration rates were statistically higher in patients who underwent AVM SRS without prior embolization (p = 0.005). A smaller AVM volume was also associated with a higher rate of obliteration (p = 0.03). Four patients (6%) sustained a hemorrhage during the latency period and 3 died. The cumulative rates of AVM hemorrhage after SRS were 6% at 1, 5, and 10 years. This correlated with an overall annual hemorrhage rate of 2.0% during the latency interval. One patient experienced a hemorrhage 9 years after confirmed MRI and angiographic obliteration. A permanent neurological deficit due to adverse radiation effects developed in 1 patient (1.6%) and temporary complications were seen in 2 additional patients (3.1%).
Stereotactic radiosurgery proved to be most effective for patients with smaller and previously nonembolized cerebellar malformations. Hemorrhage during the latency period occurred at a rate of 2.0% per year until obliteration occurred.
后颅窝动静脉畸形（AVM）具有侵袭性的自然病史和出血倾向。尽管小脑占后颅窝容积的大部分，但该区域 AVM 的立体定向放射外科（SRS）结果数据很少。作者旨在评估小脑 AVM 放射外科治疗的长期结果和风险。
本单中心回顾性分析回顾了作者在 1987 年至 2007 年期间使用伽玛刀手术的经验。在此期间，64 例患者（中位年龄 47 岁，范围 8-75 岁）因小脑 AVM 接受 SRS 治疗。47 例患者（73%）出现颅内出血。中位靶体积为 3.85cm3（范围 0.2-12.5cm3），中位边缘剂量为 21Gy（范围 15-25Gy）。
40 例患者在中位随访 73 个月（范围 4-255 个月）时通过 MRI 或血管造影证实 AVM 闭塞。完全闭塞的累计率在 3 年时为 53%，4 年时为 69%，5 年和 10 年时为 76%。在未行栓塞的 AVM SRS 患者中，闭塞率明显更高（p = 0.005）。体积较小的 AVM 也与更高的闭塞率相关（p = 0.03）。4 例（6%）患者在潜伏期内发生出血，3 例死亡。SRS 后 AVM 出血的累积发生率在 1、5 和 10 年分别为 6%。这与潜伏期内总的年出血率为 2.0%相关。1 例患者在 MRI 和血管造影证实闭塞后 9 年发生出血。1 例患者（1.6%）因放射性不良反应出现永久性神经功能缺损，2 例患者（3.1%）出现暂时并发症。
立体定向放射外科治疗对体积较小和以前未栓塞的小脑畸形患者最有效。在发生闭塞之前，潜伏期内每年出血率为 2.0%。
