O-010 Radiation Safety in Neurointervention: Is it Time for Dose Reference Levels?

Background Therapeutic neurointerventional (NI) procedures have become a significant source of radiation exposure during the treatment of cerebrovascular disease. While there are well-established radiation dose reference levels (DRLs) for diagnostic imaging, no similar NI DRLs are available. We analyzed the patient radiation dose for therapeutic NI procedures at a tertiary teaching hospital, with an aim to develop local DRLs that could form the foundation for developing national NI radiation safety guidelines. Method Retrospective analysis of radiation dose area product (DAP) in Gy. Cm 2 for consecutive patients undergoing therapeutic NI procedures between July 2011 and April 2014 was performed. NI procedures were categorized into arteriovenous malformation (AVM) embolization, cerebral aneurysm embolization (primarily coiling vs balloon/stent assisted) and cerebral vasospasm procedures. Median and inter-quartile radiation dose levels were calculated for each NI category. The 75 th percentile was deemed to be the local DRL. Wilcoxon signed-rank test was performed for statistical correlation. Results A total of 303 NI procedures were included. Patients undergoing AVM embolization received a significantly higher radiation dose (n = 44; median 338 Gy. Cm 2 [IQR 225–528 Gy. Cm 2 ]) than patients undergoing cerebral aneurysm embolization (n = 188; median 211 Gy. Cm 2 [IQR 130–328 Gy. Cm 2 ]; p = 0.003). Patients treated with primary coiling received a significantly lower radiation dose (n = 96; median 170 Gy. Cm 2 [IQR 125–282 Gy. Cm 2 ]) than patients undergoing stent/balloon assisted aneurysm embolization (n = 92; median 241 Gy. Cm 2 [IQR 145–369 Gy. Cm 2 ]); p = 0.0002). Patients undergoing cerebral vasospasm procedures (n = 71) received median 161 Gy. Cm 2 [IQR 106–219 Gy. Cm 2 ] of radiation. Conclusion Therapeutic NI procedures are a significant source of radiation exposure, particularly for AVM embolization. Proposed NI radiation DRLs based on the 75 th percentile for DAP were 528 Gy. Cm 2 , 328 Gy. Cm 2 and 219 Gy. Cm 2 for AVM embolization, cerebral aneurysm embolization and cerebral vasospasm procedures respectively. Disclosures L. Slater: None. C. Hadley: None. C. Soufan: None. H. Yu: None. M. Holt: None. W. Chong: None. H. Maroulis: None. S. Stuckey: None. R. Chandra: None.