=====Radiation induced intracranial aneurysm=====
Stereotactic radiosurgery is a well-known treatment tool for arteriovenous malformations (AVMs). The method has high validity and minimal invasiveness, but late-onset problems involving tumor formation and vasculopathy induced by radiation have been reported. 

RT is sometimes accompanied by complications and has been implicated as a risk factor for aneurysm formation
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Dho et al. present a rare case of a radiation-induced ruptured de novo [[intracranial aneurysm]] following [[Gamma Knife surgery]] (GKS) for an [[AVM]]. A 17-year-old, right-handed male underwent GKS for AVM at the left parietal lobe. After 3 years, a follow-up angiogram showed a residual AVM at the angular gyrus. Then, a 2nd GKS was performed for the residual lesion. Six years after the 1st GKS, the AVM disappeared on the angiogram. Seven years later, he suffered a sudden onset of headache. A left carotid angiogram revealed a ruptured aneurysm at the M2-M3 junction of the middle cerebral artery parietal branch. Coil embolization was performed, and the aneurysm was occluded. The patient was discharged without any neurologic deficits
((Dho YS, Kim DG, Chung HT. Ruptured de novo Aneurysm following Gamma Knife
Surgery for Arteriovenous Malformation: Case Report. Stereotact Funct Neurosurg. 
2017 Dec 1;95(6):379-384. doi: 10.1159/000481666. [Epub ahead of print] PubMed
PMID: 29190619.
)).