Radiation dose and fluoroscopy time of modern endovascular treatment techniques in patients with saccular unruptured intracranial aneurysms.

Objectives: Modern endovascular treatment of unruptured intracranial aneurysms (UIAs) demands for observance of diagnostic reference levels (DRLs). The national DRL (250 Gy cm ² ) is only defined for coiling. We provide dosimetric data for the following procedures: coiling, flow diverter (FD), Woven EndoBridge (WEB), combined techniques.
Methods: A retrospective single-centre study of saccular UIAs treated between 2015 and 2019. Regarding dosimetric analysis, the parameters dose area product (DAP) and fluoroscopy time were investigated for the following variables: endovascular technique, aneurysm location, DSA protocol, aneurysm size, and patient age.
Results: Eighty-seven patients (59 females, mean age 54 years) were included. Total mean and median DAP (Gy cm ² ) were 119 ± 73 (89-149) and 94 (73; 130) for coiling, 128 ± 53 (106-151) and 134 (80; 176) for FD, 128 ± 56 (102-153) and 118 (90; 176) for WEB, and 165 ± 102 (110-219) and 131 (98; 209) for combined techniques (p > .05). Regarding the aneurysm location, neither DAP nor fluoroscopy time was significantly different (p > .05). The lowest and highest fluoroscopy times were recorded for WEB and combined techniques, respectively (median 26 and 94 min; p < .001). A low-dose protocol yielded a 43% reduction of DAP (p < .001). Significantly positive correlations were found between DAP and both aneurysm size (r = .320, p = .003) and patient age (r = .214, p = .046).
Conclusions: This UIA study establishes novel local DRLs for modern endovascular techniques such as FD and WEB. A low-dose protocol yielded a significant reduction of radiation dose.
Key Points: • This paper establishes local diagnostic reference levels for modern endovascular treatment techniques of unruptured intracranial aneurysms, including flow diverter stenting and Woven EndoBridge device. • Dose area product was not significantly different between endovascular techniques and aneurysm locations, but associated with aneurysm size and patient age. • A low-dose protocol yielded a significant reduction of dose area product and is particularly useful when applying materials with a high radiopacity (e.g. platinum coils).