RESUMO
OBJECTIVE: To characterize radiation exposure to patients and operating room personnel during fluoroscopic procedures. METHODS: Patient dose information was collected from the imaging equipment. Real-time dosimetry was used to measure doses to the operators, scrub nurse, radiologic technologist (RT), and anesthesiologist in 39 cases of endovascular thoracoabdominal aortic aneurysm repair using fenestrated endografts. Overall equivalent doses and dose rates at time points of interest were noted and compared with the corresponding patient doses. RESULTS: The dosimeter on the anesthesia equipment received 143 µSv (38-247) more radiation per case than the average operator, and the scrub nurse and RT received 106 µSv (66-146) and 100 µSv (55-145) less, respectively. Adjusting for protective lead aprons by the Webster methodology, the average operator received an effective dose of 38 µSv. Except for the RT, personnel doses were well correlated with patient dose as measured by kerma area product (KAP) (r = .82 for average operator, r = .85 for scrub nurse, and r = .86 for anesthesia; all P < .001) but less well correlated with fluoroscopy time or cumulative air kerma (CAK). When preoperative cone beam computed tomography was performed, the equivalent dose to the RT was 1.1 µSv (0.6-1.5) when using shielding and 37 µSv (22-53) when unshielded. Digital subtraction acquisitions accounted for a large fraction of all individuals' doses. Decreasing field size (and thus, increasing magnification) was associated with decreased KAP (r = .47; P < .001) and increased CAK (r = -.56; P < .001). The square of the field size correlated strongly with the KAP/CAK ratio (r = .99; P < .001). Increased lateral angulation of the C-arm increased both CAK and KAP (at field size, 22 cm; r = .54 and r = .44; both P < .001) and the average dose rate to an operator was 1.78 (1.37-2.31) times as high in a lateral projection as in a posterior-anterior projection. CONCLUSIONS: Personnel doses were best correlated with KAP and less well correlated with fluoroscopy time or CAK. The dosimeter on the anesthesia equipment recorded the highest doses attributable to ineffective shielding. Operators can reduce the effective dose to themselves, the patient, and other personnel by minimizing the use of digital subtraction acquisitions, avoiding lateral angulation, using higher magnification levels when possible, and being diligent about the use of shielding during fluoroscopy cases.
