Brain Low-risk Aneurysm Stereotactic Radiosurgical Trial

The goal of this clinical trial is to confirm the feasibility and safety of performing radiosurgery on unruptured, low-risk aneurysms in humans. Participants will choose if they want to undergo radiosurgery or not. Participants who choose not to have radiosurgery will be assigned to the observational group. Participants who choose to have radiosurgery performed will be assigned to the radiosurgery group. Participants in both groups will attend an initial exam session as well as four follow-up sessions: Day 0 * Initial questionnaire * CTA scan * MRI * Radiosurgery performed on patients in the radiosurgery group 6 months * CTA scan * Follow-up questionnaire 12 months * CTA scan * MRI * Follow-up questionnaire 24 months * CTA scan * Follow-up questionnaire 36 months * CTA scan * MRI * Follow-up questionnaire Researchers will compare the observational group and the radiosurgery group to see if there is a difference in the incidence of aneurysm rupture during the study period (3 years). The hypothesis is that radiosurgery should not increase the risk of aneurysm rupture.