Relative Contribution of High-Dose Outliers to Cumulative Occupational Radiation Dose in the Catheterization Laboratory.

BACKGROUND

The contribution of high radiation dose outliers to cumulative occupational radiation dose is understudied.

METHODS

Physician radiation data were collected during consecutive coronary cases, and per case doses were ranked by magnitude. The relationship between the per case rank and relative contribution to cumulative dose was summed for cases ≤50th percentile and for cases >90th percentile. A similar methodology was applied for radiation doses among structural interventionalists, interventional echocardiographers, scrub technologists, and nurse circulators. Multivariable logistic regression was fit to identify independent predictors of physician radiation dose >90th percentile during coronary cases.

RESULTS

Across 363 coronary cases, the median physician radiation dose per case was 10.2 (3.2, 35.5) μSv, and the cumulative radiation dose was 13,230 μSv. Coronary cases ≤50th percentile accounted for only 5.0% of the cumulative radiation dose. Cases >90th percentile accounted for 60.3% of the cumulative dose. Cases >90th percentile accounted for 51.3%, 39.9%, 45.8%, and 64.8% of the cumulative dose among structural interventionalists, interventional echocardiographers, scrub technologists, and nurse circulators, respectively. ST-segment elevation myocardial infarction (OR, 6.2; 95% CI, 1.5-26.3; P = .01), percutaneous coronary intervention (OR, 5.6; 95% CI, 2.2-14.2; P < .001), right heart catheterization (OR, 4.4; 95% CI, 1.7-11.7; P = .003), and male sex (OR, 3.2; 95% CI, 1.3-8.0; P = .01) were independently associated with physician radiation dose >90th percentile.

CONCLUSIONS

Physician radiation dose outliers contribute disproportionately to the cumulative radiation dose, with cases above the 90th percentile accounting for 60% of the cumulative dose. High radiation dose outliers are an important target for future radiation mitigation efforts.