Direct absorbed and equivalent dose of radiation to the eyes in patients and operators during fenestrated and branched endovascular aortic repair.

Abstract

Fenestrated and branched endovascular aneurysm repairs (FB-EVAR) stand out as interventions with the highest radiation exposure to patients, operators, and staff, raising concerns for accumulating radiation doses to the eye lens. Therefore, this study aimed to describe the absorbed dose of radiation to the eyes of the patient and primary operator and relate this to indirect metrics of radiation exposure. All consecutive patients undergoing FB-EVAR between March 2022 and September 2024 as part of a prospective, nonrandomized cohort for investigational devices, were included in this cross-sectional study. To the measure absorbed dose of radiation and translate this into equivalent eye lens dose, we placed three nanoDot dosimeters (Landauer, Inc, Glenwood, IL) on each lateral periorbital skin of the patient and primary operator, and one on each eyelid of the patient. The absorbed dose left and right, and between patient and operator were compared using paired t tests. Additionally, these direct measurements were correlated (Pearson) with the indirect radiation metrics recorded by the imaging unit. There were 114 patients who were included (78 male [68%]; mean age, 71.0 ± 9.8 years). Investigational devices were off-the-shelf in 34 patients (30%) and patient-specific in 80 (70%). Among patients, the median (25th-75th percentile) absorbed dose of radiation was 0.25 mGy (0.18, 0.36 mGy) mGy at the left and 0.18 mGy (0.13, 0.26 mGy) at the right periorbital skin (mean fold difference, 1.4; 95% confidence interval, 1.3-1.5; P < .001). In the operator, the median (25th-75th percentile) absorbed dose of radiation to the periorbital skin was 0.12 mGy (0.08, 0.18 mGy) on the left (equivalent lens dose: 0.20 (0.13, 0.30) mSv) and 0.02 mGy (0.01, 0.03 mGy) on the right (equivalent lens dose: 0.03 mGy (0.02, 0.05 mGy) (mean fold difference, 7.0; 95% confidence interval, 5.7-8.6; P < .001). The indirect metrics of the radiation unit correlated weakly with the patient's absorbed dose, with correlation coefficients ranging between 0.19 (P = .048) and 0.21 (P = .025). Similarly, the correlation coefficient between fluoroscopy time and the operator's direct radiation exposure was lower at 0.29 (P = .002), whereas total dose (0.45; P < .001) and dose area product (0.49; P < .001) correlated moderately with the operator's absorbed dose. The study suggests that the left eye lens of high-volume FB-EVAR operators could accumulate doses that exceed the European and Japanese, but not United States', annual occupational limits. Metrics recorded by the radiation unit give only a moderate indication of the absorbed radiation.