Intracranial aneurysm following radiation therapy for medulloblastoma

Radiation-induced intracranial aneurysm formation is a rare but life-threatening condition with a high mortality rate secondary to rupture of the aneurysm. Furthermore, this condition can mimic tumour recurrence. Only 10 months after craniospinal radiation therapy for medulloblastoma, a 9-year-old boy developed a subarachnoid haemorrhage secondary to a ruptured saccular aneurysm arising from the distal part of the right anterior cerebral artery. The development of intracranial aneurysms and rupture following radiation damage of the arteries has been reported previously, but in no case as soon as 10 months after radiation therapy. It is important to diagnose these aneurysms as they can be successfully treated.