This descriptive systematic review aims to identify the patients' characteristics and clinical presentations of reported cases of RIA in the literature.

Radiation-induced Intracranial Aneurysms (RIA) are rare complications of radiotherapy (RT) directed to treat malignancies in the head and neck regions. Patients' characteristics, aneurysm features, and clinical presentations vary widely. 

We systematically searched PubMed/Medline, Scopus, and Web of Science databases from their inception until 2024 for reports of patients with RIA with no restrictions on age, gender, or language study. Eligible study designs included observational studies, case series, and case reports. We excluded experimental studies, editorials, and studies that don’t describe the clinical course of patients with RIA or don’t report adequate data.

Out of 1146 reports, 56 reports were included, comprising 111 patients. Males constituted the majority (n=76, 68.46%). The mean latency interval between RT exposure and aneurysm diagnosis was 10.58 (9) years. The most common primary lesions indicating the radiotherapy were nasopharyngeal carcinoma (n=38,34.2%). The most common artery involved in the formation of aneurysms was the Internal Carotid Artery (ICA) (n=66, 49.5%). The majority of patients presented with the classic symptoms of subarachnoid hemorrhage (n=54, 48.6%). Other common presentations were massive epistaxis (n=22, 19.8%) and otorrhagia (n=10, 9%). The most common modality of treatment was surgical clipping (n=20), followed by aneurysm coil embolization (n=19). 13 (11.7%) patients were discharged by permanent deficits. On the other hand, death was reported in 12 (10.8%) patients.

Clinical presentations of RIA can vary widely, although the risk of rupture remains a concern. We found that clinical manifestations of SAH were the most common presentation of RIA, with tendency toward anterior circulation involvement. We recommend the proper education of these patients with history of head and neck radiotherapy about the possible complications they may face and to emphasize the importance of follow-up visits.