Occupational and patient radiation doses in a modern cardiac electrophysiology laboratory

Occupational Risks of Radiation Exposure to Cardiologists

PURPOSE OF REVIEW

Invasive cardiologists are exposed to large amounts of ionizing radiation. This review aims to summarize the main occupational risks in a radiation-exposed cardiology practice.

RECENT FINDINGS

We carried out a literature review on the subject. The studies reviewed allowed us to list six main health risk categories possibly associated with radiation exposure among cardiologists: deoxyribonucleic acid (DNA) and biochemical damages; cancers; ocular manifestations; olfaction, vascular, and neuropsychological alterations; musculoskeletal problems; and reproductive risks. Our descriptive analysis demonstrates higher risks of DNA damage and lens opacities among radiation-exposed cardiology staff. Surveys and questionnaires have demonstrated a higher risk of musculoskeletal disease in exposed workers. Studies reported no difference in cancer frequency between radiation-exposed workers and controls. Changes in olfactory performance, neuropsychological aspects, and vascular changes have also been reported. Limited literature supports the security of continuing radiation-exposed work during pregnancy. Therefore, there is an urgent need to increase knowledge of the occupational risks of radiation exposure and to adopt technologies to reduce them.

Radiation dose during interventional cardiology procedures: portable C-arm vs. a new generation fluoroscopy system

INTRODUCTION

Occupational exposure to ionizing radiation poses health risks for veterinary interventionalists. There are limited veterinary studies evaluating radiation dose in the cardiac catheterization laboratory. The purpose of this study was to report direct radiation dose exposure to patients during common interventional cardiology procedures and compare these doses between two fluoroscopy units.

ANIMALS

One hundred and fifty-four client-owned dogs.

MATERIALS AND METHODS

Patient dose during procedures using a portable C-arm were retrospectively analyzed and compared to those performed in a contemporary interventional suite. Fluoroscopy equipment, procedure type, operator, patient weight, fluoroscopy time, dose area product, and air kerma were recorded and statistically modeled using univariable and multivariable linear regression to evaluate the effect of each factor.

RESULTS

Patient dose population (154 dogs), comprised 61 patent ductus arteriosus occlusions, 60 balloon pulmonary valvuloplasties, and 33 pacemaker implantations. Patient dose was significantly lower in the group utilizing a newer generation fluoroscopy unit vs. the group utilizing an older portable C-arm, positively correlated with patient weight, and highest during balloon pulmonary valvuloplasties compared to patent ductus arteriosus occlusions or pacemaker implantations (all p<0.010).

DISCUSSION

Newer fluoroscopy systems can be equipped with technologies that improve image quality while reducing patient dose and radiation exposure to interventional personnel.

CONCLUSIONS

We documented a significant reduction in patient radiation dose using a newer fluoroscopy system as compared to an older portable C-arm for interventional cardiology procedures in animals. Improved knowledge of patient radiation dose factors may promote better radiation safety protocols in veterinary interventional cardiology.

Patient Radiation Doses in IR Procedures: The American College of Radiology Dose Index Registry-Fluoroscopy Pilot

PURPOSE

To update normative data on fluoroscopy dose indices in the United States for the first time since the Radiation Doses in Interventional Radiology study in the late 1990s.

MATERIALS AND METHODS

The Dose Index Registry-Fluoroscopy pilot study collected data from March 2018 through December 2019, with 50 fluoroscopes from 10 sites submitting data. Primary radiation dose indices including fluoroscopy time (FT), cumulative air kerma (Ka,r), and kerma area product (PKA) were collected for interventional radiology fluoroscopically guided interventional (FGI) procedures. Clinical facility procedure names were mapped to the American College of Radiology (ACR) common procedure lexicon. Distribution parameters including the 10th, 25th, 50th, 75th, 95th, and 99th percentiles were computed.

RESULTS

Dose indices were collected for 70,377 FGI procedures, with 50,501 ultimately eligible for analysis. Distribution parameters are reported for 100 ACR Common IDs. FT in minutes, Ka,r in mGy, and PKA in Gy-cm2 are reported in this study as (n; median) for select ACR Common IDs: inferior vena cava filter insertion (1,726; FT: 2.9; Ka,r: 55.8; PKA: 14.19); inferior vena cava filter removal (464; FT: 5.7; Ka,r: 178.6; PKA: 34.73); nephrostomy placement (2,037; FT: 4.1; Ka,r: 39.2; PKA: 6.61); percutaneous biliary drainage (952; FT: 12.4; Ka,r: 160.5; PKA: 21.32); gastrostomy placement (1,643; FT: 3.2; Ka,r: 29.1; PKA: 7.29); and transjugular intrahepatic portosystemic shunt placement (327; FT: 34.8; Ka,r: 813.0; PKA: 181.47).

CONCLUSIONS

The ACR DIR-Fluoro pilot has provided state-of-the-practice statistics for radiation dose indices from IR FGI procedures. These data can be used to prioritize procedures for radiation optimization, as demonstrated in this work.

Risk of ionizing radiation in pregnancy: just a myth or a real concern?

There are natural concerns regarding the risks posed to the foetus by ionizing radiation exposure during pregnancy. Therefore, many female physicians select to avoid working in an environment associated with ionizing radiation exposure like the catheterization laboratory and even exclude training as electrophysiology, interventional cardiologists, or radiologists. For those already working in this field, pregnancy involves usually a 1-year interruption (pregnancy and maternity leave) to their careers, leading at times to delays in the decision to become pregnant. This review describes the low added risk of malformation/cancer in the offspring, highlight gaps in our understanding, discuss several common wrong beliefs, and recommend how to further decrease radiation dose, especially during pregnancy.

Radiation reduction in a modern catheterization laboratory: A single-center experience

BACKGROUND

Measures were undertaken at the Cleveland Clinic to reduce radiation exposure to patients and personnel working in the catheterization laboratories. We report our experience with these improved systems over a 7-year period in patients undergoing diagnostic catheterization (DC) and percutaneous coronary interventions (PCIs).

METHODS

Patients were categorized into preinitiative (2009-2012) and postinitiative (2013-2019) groups in the DC and PCI cohorts. Propensity score matching was done between the pre- and postinitiative groups for both cohorts based on age, sex, body surface area, total fluoroscopy time, and total acquisition time. The effectiveness of radiation reduction measures was assessed by comparing the total air kerma (K_a,r ), and fluoroscopy- and acquisition-mode air kerma in patients in the two groups.

RESULTS

In the DC cohort, there was a significant reduction in K_a,r in the postinitiative group in comparison to the preinitiative group (median, 396 vs. 857 mGy; p < 0.001). In the PCI cohort, K_a,r in the postinitiative group was 1265 mGy, which was significantly lower than the corresponding values in the preinitiative group (1994 mGy; p < 0.001). We also observed a significant reduction in fluoroscopy- and acquisition-based air kerma rates, and air kerma area product in the postinitiative group in comparison to the preinitiative group in both matched and unmatched DC and PCI cohorts after the institution of radiation reduction measures.

CONCLUSION

There was a significant and sustained reduction in radiation exposure to patients in the catheterization laboratory with the implementation of advanced protocols. Similar algorithms can be applied in other laboratories to achieve a similar reduction in radiation exposure.

Patient Radiation Doses in Interventional Radiology Procedures: Comparison of fluoroscopy dose indices from the American College of Radiology Dose Index Registry-Fluoroscopy (DIR-Fluoro) Pilot to the RAD-IR study

PURPOSE

To compare interventional radiology fluoroscopically-guided intervention (FGI) radiation dose index distributions from the American College of Radiology (ACR) Fluoroscopy Dose Index Registry (DIR-Fluoro) pilot to the Radiation Doses in Interventional Radiology (RAD-IR) study.

MATERIALS AND METHODS

Individual and grouped ACR Common IDs (procedure types) from the DIR-Fluoro pilot were matched to procedure types in the RAD-IR study. Fifteen comparisons were made. Distribution parameters including the 10^th, 25^th, 50^th, 75^th, and 95^th percentiles were compared for fluoroscopy time (FT), cumulative air kerma (K_a,r), and kerma area product (P_KA). Two derived indices were computed using median dose indices. The procedure-averaged reference air kerma rate (K_a,r¯) was computed as K_a,r / FT. The procedure-averaged X-ray field size at the reference point (A_r¯) was computed as P_KA / (K_a,r * 1,000).

RESULTS

Median FT was equally likely to be higher or lower in the DIR-Fluoro pilot compared to RAD-IR, while maximum FT was almost twice as likely to be higher in DIR-Fluoro than RAD-IR. Median K_a,r was lower in the DIR-Fluoro pilot for all procedures, as was median P_KA. The maximum K_a,r and P_KA were more often higher in the DIR-Fluoro pilot compared to RAD-IR. K_a,r¯ followed the same pattern as K_a,r, while A_r¯ was often greater in DIR-Fluoro.

CONCLUSIONS

Median dose indices have decreased since the RAD-IR study. Typical K_a,r rates are lower, a result of the use of lower default dose rates. However, opportunities for quality improvement exist, including a renewed focus on tight collimation of the imaging field of view.

Collar badge lens dose equivalent values among U.S. physicians performing fluoroscopically-guided interventional procedures

PURPOSE

To describe the range of occupational badge dose readings and annualized dose records among physicians performing fluoroscopically guided interventional (FGI) procedures using job title information provided by the same three major medical institutions in 2009, 2012, and 2015.

METHODS

The Radiation Safety Office of selected hospitals was contacted to request assistance with identifying physicians in a large commercial dosimetry database. All entries judged to be uninformative of occupational doses to FGI procedures staff were excluded. Monthly and annualized doses were described with univariate statistics and box-and-whisker plots.

RESULTS

The dosimetry dataset of interventional radiology staff contains 169 annual dose records from 77 different physicians and 698 annual dose records from 455 non-physicians. The median annualized lens dose equivalent values among physicians (11.9 mSv; IQR=6.9-20.0) was nearly threefold higher than non-physician medical staff assisting with FGI procedures (4.0 mSv; IQR=1.8-6.7) (P<0.001). During the study period, without eye protection, 25% (23 of 93) of the physician annualized lens dose equivalent values may have exceeded 20 mSv; for non-physician medical staff, this value was may have been exceeded 3.5% (6 of 173) of the time. However, these values do not account for eye protection.

CONCLUSION

The findings from this study highlight the importance of mitigating occupational dose to the eyes of medical staff, particularly physicians, performing or assisting with FGI procedures. Training on radiation protection principles, the use of personal protective equipment, and patient radiation dose management can all help ensure occupational radiation dose is adequately controlled.

Fluoroscopy time and scattered radiation during electrophysiology procedures: analysis of one-year data of a laboratory providing electrophysiology training

OBJECTIVES

Patients and medical staff expose to significant radiation during electro-physiological (EP) procedures. There are few data regarding the leading factors of longer fluoroscopy time and higher scattered radiation in a laboratory giving EP training during those interventions.

MATERIAL AND METHODS

The patients' recordings that underwent EP procedure in a single centre arrhythmia unit from February 2019 to January 2020 were examined. Prospectively collected data regarding procedure duration, fluoroscopy time and total air kerma, demographic characteristics of the patients, type of procedure, success of ablation and the use of electro anatomic mapping were retrospectively evaluated. Predictors of total air kerma were analysed with linear regression analysis.

RESULTS

Study population consisted of 437 patients with a median age of 47 (39-56); 184 (42.1%) were male. Median fluoroscopy time was 768 (420-1320) seconds and median cumulative air kerma was 369 (191-750) mGy. Fluoroscopy time and cumulative air kerma were significantly lower in diagnostic EP studies compared to other procedures. There was no difference in terms of total air kerma between the procedures other than the diagnostic EP study. In multivariable linear regression analysis; body surface area, fluoroscopy time, not using the electro-anatomical mapping, unsuccessful ablation and atrial flutter ablation were predictors of total air kerma in EP studies performed by trainees.

CONCLUSION

Scattered radiation during EP procedures performed by in-training operators is related with some factors. Awareness about those may help to effort reducing the harmful effect of ionising radiation.