Horton Tristram G, Ma Peter H, Cockroft Kevin M
Department of Neurosurgery, Penn State University - Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA.
Department of Surgery, Penn State University - Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA.
J Radiosurg SBRT. 2012;2(1):79-82.
Reports of the development of true intracranial aneurysms after radiosurgery are exceedingly rare and unconvincing. We report the case of a young boy who developed a posterior communicating artery aneurysm after the Gamma Knife radiosurgical treatment of a thalamic AVM. This ten year-old presented with left upper extremity tremors. MRI/MRA revealed a right thalamic AVM. No intracranial aneurysms were found on initial angiography. The patient underwent two-stage endovascular embolization of his AVM followed by Gamma Knife radiosurgical treatment (18 Gy delivered to the 50% isodose line). Follow up angiogram at 38 months confirmed obliteration of the AVM, but revealed a new 2.2 x 1.5 mm aneurysm located at the origin of the right posterior communicating artery. A MRA obtained 5 months later (43 months after treatment) demonstrated regression of the aneurysm. This is the first report of the development of an intracranial aneurysm after Gamma Knife radiosurgery in a child and the first description to include pre and post-treatment angiography that clearly demonstrates interval aneurysm development. Although the aneurysm showed subsequent regression during continued follow-up, this report illustrates the critical importance of post-treatment angiography for patients with intracranial AVM treated in this manner.
放射外科手术后发生真性颅内动脉瘤的报道极为罕见且难以令人信服。我们报告一例小男孩在接受伽玛刀放射外科治疗丘脑动静脉畸形（AVM）后发生后交通动脉瘤的病例。该10岁患儿表现为左上肢震颤。MRI/MRA显示右侧丘脑AVM。初次血管造影未发现颅内动脉瘤。患者接受了两阶段的AVM血管内栓塞治疗，随后进行伽玛刀放射外科治疗（50%等剂量线给予18 Gy）。38个月时的随访血管造影证实AVM闭塞，但显示右侧后交通动脉起始处有一个新的2.2×1.5 mm动脉瘤。5个月后（治疗后43个月）获得的MRA显示动脉瘤缩小。这是儿童伽玛刀放射外科治疗后发生颅内动脉瘤的首例报道，也是首次包含治疗前后血管造影的描述，清晰显示了动脉瘤的间隔期发展。尽管在持续随访中动脉瘤随后缩小，但本报告说明了治疗后血管造影对于以这种方式治疗的颅内AVM患者的至关重要性。
