Retrospective study of patients radiation dose during cardiac catheterization procedures

Evolving operator practices reduced patient radiation dose in interventional cardiology: Trends in a single center

BACKGROUND

This retrospective study addresses the role of operator and fluoroscopy equipment in reducing patient radiation exposure in the Cath lab.

METHODS

Data from 99,400 procedures performed in our institution between 2007 and 2019 were reviewed. Dosimetric parameters included reference point air kerma (Ka,r), Kerma Area Product (PKA), fluoroscopic time, and contrast volume. Results are characterized by their 50th and 99th percentiles. Data from a subset of fluoroscopes that were in continuous use and a subset of operators who used the same "continuous" fluoroscope in every year of the study were also analyzed.

RESULTS

For all procedures, median Ka,r declined by 63%, from 1.5 to 0.5Gy; 99th percentiles declined by 44%, from 8.6 to 4.8Gy. For the 3 "continuous fluoroscopes" median Ka,r declined by 60% from 1.6 to 0.6Gy; 99th percentile by 52% from 9.1 to 4.4Gy. The all-procedure median contrast volume declined by 53%, from 150 to 70ml; 99th percentile by 42% from 600 to 350ml. The all-procedure median fluoroscopy time declined by 2%; the 99th percentile increased by 32%. In the continuous subset, median fluoroscopy time declined by 20%; 99th percentile increased by 5%. For the operator's subset, the median Ka,r declined by 43% (P = .0362); the 99th percentile decreased by 22% (P = .0481). Substantial radiation dose procedures decreased from 7% to 0.8% of the procedure volume.

CONCLUSIONS

There was a significant reduction in patient radiation (Ka,r and PKA) and contrast volume during the study period driven by systematic and operator practice changes.

Implementing Patient Protection Radiation Dose Alerts for Pediatric Cardiac Catheterization Examinations

Background

Advancements in cardiac catheterization have improved survival for pediatric congenital heart disease patients, but the associated ionizing radiation risks necessitate ethical consideration.

Methods

This study presents an empirical model, developed from 3131 unique pediatric procedures, to establish alert levels based on a patient's lateral thickness of the thorax for various procedural categories during diagnostic or interventional cardiac catheterization. The model uses linear regression of logarithmic reference air kinetic energy released per unit mass (KERMA) and air KERMA area product, also referred to as dose area product, to set alert levels at the top 95% and 99% of patient data.

Results

Coefficients of the regression fits are provided for diagnostic and interventional procedural groups and fluoroscopic plane allowing any facility to scale the results of this study's single facility data to model their practice's unique procedural dose levels.

Conclusions

The proposed method allows institutions to tailor dose alert levels to their specific pediatric populations to reduce overexposure events.

Anthropometric parameters and radiation doses during percutaneous coronary procedures

PURPOSE

Body size is a major determinant of patient's dose during percutaneous coronary interventions (PCI). Body mass index, body surface area (BSA), lean body mass and weight are commonly used estimates for body size. We aim to identify which of these measures and which procedural/clinical characteristics can better predict received dose.

METHODS

Dose area product (DAP, Gycm²), fluoroscopy DAP rate (Gycm²/min), fluoroscopy DAP (Gycm²), cine-angiography DAP (Gycm²), Air Kerma (mGy) were selected as indices of patient radiation dose. Different clinical/procedural variables were analysed in multiple linear regression models with previously mentioned patient radiation dose parameters as end points. The best model for each of them was identified.

RESULTS

Overall 6623 PCI were analysed, median fluoroscopy DAP rate was 35 [IQR 2.7,4.4] Gycm², median total DAP was 62.7 [IQR 38.1,107] Gycm². Among all anthropometric variables, BSA showed the best correlation with all radiation dose parameters considered. Every 1 m² increment in BSA added 4.861 Gycm²/min (95% CI [4.656, 5.067]) to fluoroscopy DAP rate and 164 Gycm² (95% CI [145.3, 182.8]) to total DAP. Height and female sex were significantly associated to a reduction in fluoroscopy DAP rate and total DAP. Coronary angioplasty, diabetes, basal creatinine and the number of treated vessels were associated to higher values.

CONCLUSIONS

Main determinants of patient radiation dose are: BSA, female sex, height and number of treated vessels. In an era of increasing PCI complexity and obesity prevalence, these results can help clinicians tailoring X-ray administration to patient's size.

Patient exposure dose in interventional cardiology per clinical and technical complexity levels. Part 1: results of the VERIDIC project

BACKGROUND

Patients can be exposed to high skin doses during complex interventional cardiology (IC) procedures.

PURPOSE

To identify which clinical and technical parameters affect patient exposure and peak skin dose (PSD) and to establish dose reference levels (DRL) per clinical complexity level in IC procedures.

MATERIAL AND METHODS

Validation and Estimation of Radiation skin Dose in Interventional Cardiology (VERIDIC) project analyzed prospectively collected patient data from eight European countries and 12 hospitals where percutaneous coronary intervention (PCI), chronic total occlusion PCI (CTO), and transcatheter aortic valve implantation (TAVI) procedures were performed. A total of 62 clinical complexity parameters and 31 technical parameters were collected, univariate regressions were performed to identify those parameters affecting patient exposure and define DRL accordingly.

RESULTS

Patient exposure as well as clinical and technical parameters were collected for a total of 534 PCI, 219 CTO, and 209 TAVI. For PCI procedures, body mass index (BMI), number of stents ≥2, and total stent length >28 mm were the most prominent clinical parameters, which increased the PSD value. For CTO, these were total stent length >57 mm, BMI, and previous anterograde or retrograde technique that failed in the same session. For TAVI, these were male sex, BMI, and number of diseased vessels. DRL values for Kerma-area product (P_KA), air kerma at patient entrance reference point (K_a,r), fluoroscopy time (FT), and PSD were stratified, respectively, for 14 clinical parameters in PCI, 10 in CTO, and four in TAVI.

CONCLUSION

Prior knowledge of the key factors influencing the PSD will help optimize patient radiation protection in IC.

Establishing a priori and a posteriori predictive models to assess patients' peak skin dose in interventional cardiology. Part 2: results of the VERIDIC project

BACKGROUND

Optimizing patient exposure in interventional cardiology is key to avoid skin injuries.

PURPOSE

To establish predictive models of peak skin dose (PSD) during percutaneous coronary intervention (PCI), chronic total occlusion percutaneous coronary intervention (CTO), and transcatheter aortic valve implantation (TAVI) procedures.

MATERIAL AND METHODS

A total of 534 PCI, 219 CTO, and 209 TAVI were collected from 12 hospitals in eight European countries. Independent associations between PSD and clinical and technical dose determinants were examined for those procedures using multivariate statistical analysis. A priori and a posteriori predictive models were built using stepwise multiple linear regressions. A fourfold cross-validation was performed, and models' performance was evaluated using the root mean square error (RMSE), mean absolute percentage error (MAPE), coefficient of determination (R²), and linear correlation coefficient (r).

RESULTS

Multivariate analysis proved technical parameters to overweight clinical complexity indices with PSD mainly affected by fluoroscopy time, tube voltage, tube current, distance to detector, and tube angulation for PCI. For CTO, these were body mass index, tube voltage, and fluoroscopy contribution. For TAVI, these parameters were sex, fluoroscopy time, tube voltage, and cine acquisitions. When benchmarking the predictive models, the correlation coefficients were r = 0.45 for the a priori model and r = 0.89 for the a posteriori model for PCI. These were 0.44 and 0.67, respectively, for the CTO a priori and a posteriori models, and 0.58 and 0.74, respectively, for the TAVI a priori and a posteriori models.

CONCLUSION

A priori predictive models can help operators estimate the PSD before performing the intervention while a posteriori models are more accurate estimates and can be useful in the absence of skin dose mapping solutions.

Comparison of radiation doses between hepatic artery infusion chemotherapy and transarterial chemoembolization for liver cancer

Objective

To analyze the radiation dose received by patients during hepatic artery infusion chemotherapy (HAIC) and transarterial chemoembolization (TACE) procedures and the related influencing factors.

Methods

Data of 162 cases in the HAIC group and 230 cases in the TACE group were collected. The included covariates were Age (<45/45–59/≥60 years), BMI levels (underweight/normal weight/obesity), focus Dye of tumor (present/absent), lesion size (<5cm/≥5cm), superselection (present/absent), hepatic vascular variation (present/absent). The endpoints were postoperative dose-area product (DAP), exposure time and Air kerma (AK).

Results

Of all included patients, the HAIC group patients were younger than those in the TACE group (P ​= ​0.028). The proportion of patients with large lesions in the HAIC group was higher than the TACE group (45.7% vs. 33.9%, P ​= ​0.019). The proportion of patients who had superselection was lower in the HAIC group as compared to the TACE group (61.7% vs. 82.2%, P ​< ​0.001). Generally, the HAIC group has lower DAP, exposure time and AK by 36.3% (P ​< ​0.001), 38.2% (P ​< ​0.001), and 41.3% (P ​< ​0.001) than the TACE group, respectively. Linear regression analysis showed the procedure method (HAIC/TACE, P ​< ​0.001), type of DSA machine (Pheno/FD20, P ​< ​0.001), BMI levels (P ​< ​0.001), age (P ​= ​0.021), lesion size (<5cm/≥5 ​cm, P ​= ​0.031) significantly correlated with low DAP. In the HAIC group, the type of DSA machine and BMI correlated with the radiation dose, while in the TACE group, the type of DSA machine, BMI, and lesion size correlated with the radiation dose.

Conclusion

Compared with TACE, HAIC enables doctors and patients to receive lower radiation doses. Obese patients in both HAIC and TACE groups increase the radiation exposure in interventional doctors and patients, but large lesions only affect the radiation dose in the TACE procedure.

Occupational hazard of fluoroscopy: An invisible threat to orthopaedic surgeons

The use of fluoroscopy is widespread within different medical specialties. Improper protection may cause significant radiation hazard to medical personnel. To evaluate the concepts on radiation safety and fluoroscopy use among orthopaedic surgeons and to reflect our current training on this issue, a survey was distributed to perform an audit in our department, an academic unit. Twenty-eight orthopaedic surgeons replied. Amongst our participants, 96.4% used a lead apron at all times. Only 33% used a thyroid shield, 67% never used radiation goggles and 96% never used radiation protection gloves. 53.6% and 46.4% of participants position the fluoroscopy incorrectly in the anteroposterior and lateral positions, respectively, during use. There is clearly a need for improved safety amongst orthopaedic surgeons. A literature review was further performed, showing the hazards of fluoroscopy for doctors, including the risk of cataracts, radiation dermatitis, skin cancer and thyroid cancer. Hazards specific to females, including breast cancer risk, and in-utero irradiation of foetus were also thoroughly discussed. Recommendations towards radiation safety and practical measures to reduce fluoroscopy radiation hazard during procedure were made. Education and training to doctors on this invisible hazard is strongly advised.