Step back from the patient: reduction of radiation dose to the operator by the systematic use of an automatic power injector for contrast media in an interventional angiography suite

SCAI expert consensus update on best practices in the cardiac catheterization laboratory: This statement was endorsed by the American College of Cardiology (ACC), the American Heart Association (AHA), and the Heart Rhythm Society (HRS) in April 2021

The current document commissioned by the Society for Cardiovascular Angiography and Interventions (SCAI) and endorsed by the American College of Cardiology, the American Heart Association, and Heart Rhythm Society represents a comprehensive update to the 2012 and 2016 consensus documents on patient-centered best practices in the cardiac catheterization laboratory. Comprising updates to staffing and credentialing, as well as evidence-based updates to the pre-, intra-, and post-procedural logistics, clinical standards and patient flow, the document also includes an expanded section on CCL governance, administration, and approach to quality metrics. This update also acknowledges the collaboration with various specialties, including discussion of the heart team approach to management, and working with electrophysiology colleagues in particular. It is hoped that this document will be utilized by hospitals, health systems, as well as regulatory bodies involved in assuring and maintaining quality, safety, efficiency, and cost-effectiveness of patient throughput in this high volume area.

Optimizing Staff Dose in Fluoroscopy-Guided Interventions by Comparing Clinical Data with Phantom Experiments

PURPOSE

To evaluate conditions for minimizing staff dose in interventional radiology, and to provide an achievable level for radiation exposure reduction.

MATERIALS AND METHODS

Comprehensive phantom experiments were performed in an angiography suite to evaluate the effects of several parameters on operator dose, such as patient body part, radiation shielding, x-ray tube angulation, and acquisition type. Phantom data were compared with operator dose data from clinical procedures (n = 281), which were prospectively acquired with the use of electronic real-time personal dosimeters (PDMs) combined with an automatic dose-tracking system (DoseWise Portal; Philips, Best, The Netherlands). A reference PDM was installed on the C-arm to measure scattered radiation. Operator exposure was calculated relative to this scatter dose.

RESULTS

In phantom experiments and clinical procedures, median operator dose relative to the dose-area product (DAP) was reduced by 81% and 79% in cerebral procedures and abdominal procedures, respectively. The use of radiation shielding decreased operator exposure up to 97% in phantom experiments; however, operator dose data show that this reduction was not fully achieved in clinical practice. Both phantom experiments and clinical procedures showed that the largest contribution to relative operator dose originated from left-anterior-oblique C-arm angulations (59%-75% of clinical operator exposure). Of the various x-ray acquisition types used, fluoroscopy was the main contributor to procedural DAP (49%) and operator dose in clinical procedures (82%).

CONCLUSIONS

Achievable levels for radiation exposure reduction were determined and compared with real-life clinical practice. This generated evidence-based advice on the conditions required for optimal radiation safety.

Radiation exposure to operating room personnel and patients during endovascular procedures

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.