Certain Coronary Cases, Like STEMI, Tip Total Radiation Exposure Higher

A small percentage of coronary interventions contribute disproportionately to the cumulative radiation exposure of operators and other cath lab staff, new data suggest.

Those excessive exposures—defined as coronary cases exceeding the 90th percentile for radiation doses—accounted for 51.3%, 39.9%, 45.8%, and 64.8% of the cumulative dose of structural interventionalists, interventional echocardiographers, scrub technologists, and nurse circulators, respectively.

“The other important takeaway was that if you sum up the doses of cases below the 50th percentile, that accounted for only 5% of the cumulative dose,” said Ryan D. Madder, MD (Corewell Health William Beaumont University Hospital Heart & Vascular, Royal Oak, MI), lead author of the study published in the January 2026 issue of the JSCAI.

The findings support the idea that median dose as a measure of occupational radiation exposure for cath lab teams “is probably actually a poor marker of cumulative dose,” said Madder.

In the United States, the annual cumulative limit of radiation exposure for physicians and cath lab staff is 50,000 μSv. Europe uses a lower threshold of 20,000 μSv. As Madder and colleagues note, the need to stay within the thresholds can impact everything from the number of cases an operator can perform, and subsequent compensation, to negative consequences for patient care. In a recent survey conducted by the Society for Cardiovascular Angiography and Interventions (SCAI), 17% of interventional cardiologists admitted to not wearing their radiation dosimeter at times in cases to limit the tracking of their cumulative exposure.

“It only takes a small number of cases where you have very high exposures to really crank up your cumulative dose,” Madder told TCTMD. “For physicians who are approaching their cumulative dose and who have done that in the past or just thought about removing their badge, I’m hoping that our paper sheds a little bit of light on which cases may be contributing to the largest chunk of their cumulative dose . . . so they may be able to favorably reduce it.”

In this study of over 300 coronary procedures, the types that cranked up the cumulative dose the most were STEMI cases.

“That’s really important because when we’re coming in emergently to do cases after hours for instance, I think a lot of times we forget about the importance of radiation safety,” Madder said. “We forget about putting the shields where they need to be to protect ourselves, and everybody is focused on getting the artery open for the sake of the patient. But we may be putting ourselves at undue risk in those cases by not concentrating enough on radiation safety.”

It only takes a small number of cases where you have very high exposures to really crank up your cumulative dose. Ryan D. Madder

In an accompanying editorial, Zaid Almarzooq, MD (Harvard Medical School and Veterans Affairs Boston Healthcare, MA), and Celina M. Yong, MD (Stanford School of Medicine and Veterans Affairs Palo Also Healthcare Systems, CA), agree that staff may be distracted from best practices for radiation safety in emergency situations where they are rushing to meet metrics like door-to-balloon times.

“This underscores the need for real-time radiation dose monitoring for operators, which may diverge from the real-time radiation doses routinely tracked for patients,” they write.

Almarzooq and Yong also say that given the single-center nature of the study, expanding on these findings “will also support broad adoption of standardized practices, including integration of radiation-dose analytics into hospital safety metrics and much-needed regulatory consistency across states.”

Homing in on the Outliers

Of the 363 coronary angiography cases included in the study, 34.2% involved PCI, 23.4% right-heart catheterization, and 2.8% STEMI. In all cases, operators wore conventional lead aprons and a thyroid collar and used shielding according to the institutional standards for the intervention. More than one-third of cases involved use of a radiation-absorbing pad.

The median physician radiation dose per case was 10.2 μSv, with a cumulative dose of 13,230 μSv. For all operators, cases above the 90th percentile for exposure accounted for 60.3% of their cumulative dose.

In addition to STEMI, which had a sixfold higher likelihood of physicians being exposed to radiation doses exceeding the 90th percentile, other predictors of physician radiation dose exposures above this percentile were PCI (OR 5.6; 95% CI 2.2-14.2), right-heart catheterization (OR 4.4; 95% CI 1.7-11.7), and male sex (OR 3.2; 95% CI 1.3-8.0).

Several key radiation dose metrics affecting patients also trended higher when the operator had exposures above the 90th percentile. This included a threefold higher fluoroscopy time, a twofold higher air kerma, and a 1.8-fold higher dose area product.

Madder said validation of these findings is needed, and he encouraged to help cath lab staff better understand their radiation exposure risks and make plans to reduce them.

“The first step is maybe just really emphasizing that these outlier doses are probably having a very significant impact on our cumulative doses and we need to all be aware of that,” he added.

Given the emergence of novel enhanced radiation protection devices (ERPD), this type of awareness may also help direct the use of ERPD resources by applying them in complex cases with higher risk of outlier dose exposures.

“Whether intentionally funneling cases anticipated to be complex to procedure rooms having an ERPD available would result in lower radiation doses to physicians and staff members requires further study,” Madder and colleagues add.

While time is of the essence in STEMI cases and may be a reason for some to not integrate ERPDs into their workflow, recent data suggest using them don’t necessarily slow down operators or other cath lab staff.

“I think the perception that a lot of operators and maybe cath labs in general have is that they just don’t have the time to get these set up,” Madder added. “But I would argue that the more you use these, the more your team uses them, the more efficient you as a team are going to be at setting these up.”

For Almarzooq and Yong, the findings are a starting point to try to dissect some of the predictors of outlier exposure further. While patient sex emerged as a predictor, more context is needed to understand whether the finding is due to things such as confounding with increased use of PCI, case complexity, anatomic differences, or the impact of body size on scatter radiation, for example. Also important, they add, will be analysis of practice variation at the provider level to see if any further insights into outliers emerge.