Cumulative Radiation Exposure in Aneurysmal Subarachnoid Hemorrhage: A Single-Institution Analysis

Objective: Diagnosis and management of aneurysmal subarachnoid hemorrhage (aSAH) depend heavily on imaging modalities that repeatedly expose patients to ionizing radiation. There is limited literature on cumulative radiation exposure in this patient population, which is a problem compounded by wide variation among institutions. The present study quantifies the cumulative cranial exposure to ionizing radiation resulting from diagnostic medical imaging and medical procedures during initial hospitalization for ruptured aSAH at a single academic institution and estimates the risk of future adverse events related to radiation injury.

Methods: We performed a retrospective observational study of adults who presented to our institution during a nearly 3-year period with acute-onset aSAH, which was confirmed with diagnostic imaging, and had the aneurysm treated with either surgical clip ligation or endovascular embolization.

Results: A total of 131 patients met the inclusion criteria. Eighty-eight patients (67%) were treated with endovascular embolization and 43 (32%) were treated with clip ligation. We found the average radiation dose to the head during the incident hospitalization for aSAH to be 4.40 Gy (95% confidence interval, 3.91-4.89). Angiography and interventional radiology procedures accounted for most of this exposure.

Conclusions: Most patients were exposed to levels of ionizing radiation that put them at considerable risk of deterministic radiation injury. Providers should be aware of the potential consequences of acute and long-term radiation exposure in this patient population, so they can monitor and counsel individuals accordingly and take steps to safely limit radiation exposure during aSAH management.