Radiation-Induced Cerebral Aneurysm Successfully Treated with Endovascular Coil Embolization

In a 30-year-old male, multiple cerebral aneurysms developed 19 years after receiving 60 Gy of irradiation for craniophariginoma. Angiogram revealed right IC-PC and upper basilar trunk aneurysms in addition to atherosclerotic change. The right IC-PC aneurysm was wrapped and the basilar trunk aneurysm located between the origins of SCA and AICA was treated by endovascular coil embolization. The packing of the aneurysm was complete, but stenosis of the basilar artery appeared. The patient was discharged uneventfully and follow-up angiogram 6 months later demonstrated that the aneurysm had disappeared and the patency of the basilar artery had been preserved. Radiation-induced intracranial vasculopathy is a well-recognized phenomenon, but aneurysm formation is less common than arterial occlusive lesion. However, the mortality rate after bleeding is so high that immediate diagnosis and treatment by direct surgery or coil embolization are necessary.