Radiation-associated lens changes in the cardiac catheterization laboratory: Results from the IC-CATARACT (CATaracts Attributed to RAdiation in the CaTh lab) study

Comprehensive radiation shield minimizes operator radiation exposure in coronary and structural heart procedures

OBJECTIVES

This study evaluated the efficacy of a novel comprehensive shield designed to minimize radiation exposure (RE) to Physicians performing coronary and structural heart procedures.

BACKGROUND

The Protego™ radiation shielding system (Image Diagnostics Inc., Fitchburg, Ma) is designed to provide comprehensive protection from RE and has been State certified sufficient to allow operators to perform procedures without orthopedically burdensome lead aprons.

METHODS

This single center two-group cohort study assessed the efficacy of this shield in a large number of cardiac procedures (coronary and structural), comparing operator RE compared to standard protection methods (personal lead apparel and "drop down" shield).

RESULTS

The Protego™ system reduced operator RE by 99 % compared to Standard Protection. RE was significantly lower at both "Head" level by thyroid median dose 0.0 (0.0, 0,0) vs 5.7 (2.9, 8.2) μSv (p < 0.001), as well as waist dose 0.0 (0.0, 0.0) vs 10.0 (5.0, 16.6) μSv (p < 0.001). "Zero" Total RE was documented by Raysafe™ in 64 % (n = 32) of TAVR cases and 73.2 % (n = 183) of the coronary cases utilizing Protego™. In contrast, standard protection did not achieve "Zero" exposure in a single case. These dramatic differences in RE were achieved despite higher fluoroscopy times in the Protego™ arm (11.9 ± 8.6 vs 14.3 ± 12.5 min, p = 0.015). Per case procedural exposure measured by Dose Area Product was higher in the Protego™ group compared to standard protection (115.4 ± 139.2 vs 74.9 ± 69.3, p < 0.001).

CONCLUSION

The Protego™ shield provides total body RE protection for operators performing both coronary and structural heart procedures. This shield allows procedural performance without the need for personal lead aprons and has potential to reduce catheterization laboratory occupational health hazards.

A multicentre survey of knowledge and implementation of radiation protection techniques in cardiac cath-lab medical personnel

BACKGROUND

Awareness of radiation hazards and methods to reduce radiation dose is a sine qua non for all staff working in the cath-lab for their own safety and their patient's safety.

RESULTS

There were large variations in the implementation of radiation protection techniques with overall inadequate radiation risk knowledge. Some members of the cath-lab team are at higher risk of radiation-induced side effects, including the fellows, nurses, technicians, and anaesthesiologists because they spent longer time in the cath-lab and/or their position in relation to the source of radiation. About 10% of the participants have reported different health problems potentially induced by radiation exposure.

CONCLUSIONS

There is lack of radiation risks knowledge with inadequate radiation protection practice among cath-lab team. Some members such as fellows, nurse, technicians, and cardiac anaesthesiologist are at higher risks. They represent the forgotten members of the Cath-Lab team.

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.

Assessment of patient and occupational exposure and radiation risk from cath-lab procedure

Due to the extended localized fluoroscopy, many radiographic exposures, and multiple procedures that might result in tissue reaction, patients and personnel received a significant radiation dose during interventional cardiology (IR) procedures. This study aims to calculate the radiation risk and assess patient and staff effective doses during IC procedures. Thirty-two patients underwent a Cath lab treatment in total. Ten Cath lab personnel, including six nurses, two cardiologists, and two X-ray technologists. Optical stimulating-luminescent dosimeters (OSL) (Al2O3:C) calibrated for this purpose were used to monitor both occupational and ambient doses. Using an automated OSL reader, these badges were scanned. The Air Kerma (mGy) and Kerma Area Products (KAP, mGy.cm2) have a mean and standard deviation (SD) of 371 ± 132 and 26052, respectively. The average personal dose equivalent (mSv) and its range for cardiologists, nurses and X ray technologists were 1.11 ± 0.21 (0.96-1.26), 0.84 ± 0.11 (0.68-1.16), and 0.68 ± 0.014 (0.12-0.13), respectively. The current study findings showed that the annual effective dose for cardiologists, nurses, and X-ray technologists was lesser than the yearly occupational dose limit of 20 mSv recommended by national and international guidelines. The patients' doses are comparable with some previously published studies and below the tissue reaction limits.

Robotic Percutaneous Coronary Intervention (R-PCI): Time to Focus on the Pros and Cons

AIM

To assess the safety, efficiency, and device compatibility of the Second Generation Robotic System.

METHODS

Data on Robot-Assisted PCI (R-PCI) is frequently insufficient in India. Many articles were published in national, non-indexed journals that are not available online and are difficult to obtain. Recognizing these constraints, the current review is intended to compile the available data on this important new innovation technique. This review could encourage future research and serve as a valuable source of information.

RESULTS

/Conclusion: In terms of procedure efficiency, operator radiation reduction, and safety, the recent implementation and development of second-generation robotic systems have had a significant impact on interventional cardiology. This technology will play a significant role in the future of interventional cardiology as advancements eliminate the need for manual assistance, improve devices compatibility, and expand the use of robotics for telestenting procedures. A larger study demonstrating the safety and feasibility of tele-stenting over greater geographic distances, as well as addressing fundamental technical difficulties, would be required before attempting R-PCI.

Educational Experience of Interventional Cardiology Fellows in the United States and Canada

BACKGROUND

The COVID-19 pandemic and iodinated contrast shortage may have affected interventional cardiology (IC) fellowship training.

OBJECTIVES

The aim of this study was to investigate the educational experience of first-year IC fellows in the United States and Canada.

METHODS

A 59-question online survey was conducted among 2021-2022 first-year IC fellows in the United States and Canada.

RESULTS

Of the 360 IC fellows invited to participate, 111 (31%) responded; 95% were from the United States, and 79% were men. Participants were mostly from university programs (70%), spent 61 to 70 hours/week in the hospital, and had an annual percutaneous coronary intervention case number of <200 (5%), 200 to 249 (8%), 250 to 349 (33%), 350 to 499 (39%), 500 to 699 (12%), or ≥700 (3%). For femoral access, a micropuncture needle was used regularly by 89% and ultrasound-guided puncture by 81%, and 43% used vascular closure devices in most cases (>80%). Intravascular ultrasound was performed and interpreted very comfortably by 62% and optical coherence tomography (OCT) by 32%, and 20% did not have access to OCT. Approximately one-third felt very comfortable performing various atherectomy techniques. Covered stents, fat embolization, and coil embolization were used very comfortably by 14%, 4%, and 3%, respectively. Embolic protection devices were used very comfortably by 11% to 24% of IC fellows. Almost one-quarter of fellows (24%) were warned about their high radiation exposure. Eighty-four percent considered IC fellowship somewhat or very stressful, and 16% reported inadequate psychological support.

CONCLUSIONS

This survey highlights opportunities for improvement with regard to the use of intravascular imaging, atherectomy techniques, complication prevention and management strategies, radiation awareness and mitigation, and psychological support.

Individual response of the ocular lens to ionizing radiation

PURPOSE

Cataract (opacification of the ocular lens) is a typical tissue reaction (deterministic effect) following ionizing radiation exposure, for which prevention dose limits have been recommended in the radiation protection system. Manifestations of radiation cataracts can vary among individuals, but such potential individual responses remain uncharacterized. Here we review relevant literature and discuss implications for radiation protection. This review assesses evidence for significant modification of radiation-induced cataractogenesis by age at exposure, sex and genetic factors based on current scientific literature.

CONCLUSIONS

In addition to obvious physical factors (e.g. dose, dose rate, radiation quality, irradiation volume), potential factors modifying individual responses for radiation cataracts include sex, age and genetics, with comorbidity and coexposures also having important roles. There are indications and preliminary data identifying such potential modifiers of radiation cataract incidence or risk, although no firm conclusions can yet be drawn. Further studies and a consensus on the evidence are needed to gain deeper insights into factors determining individual responses regarding radiation cataracts and the implications for radiation protection.

A novel comprehensive radiation shielding system eliminates need for personal lead aprons in the catheterization laboratory

OBJECTIVES

This clinical study evaluated the efficacy of a novel radiation shielding system for the cardiac catheterization laboratory designed to provide comprehensive protection that obviates the need for personal lead aprons.

BACKGROUND

Invasive Cardiologists are exposed to occupational health hazards related directly to radiation exposure (RE) and indirectly to the orthopedic burden of wearing only partially protective lead aprons. Innovations to reduce these risks are warranted. A novel comprehensive shielding system (Protego^TM , Image Diagnostics Inc, Fitchburg, Ma) has been validated in pre-clinical studies to provide excellent radiation protection, sufficient for the State of Michigan to certify it for use without need for personal lead aprons.

METHODS

This clinical analysis measured RE to a single Physician operator utilizing the Protego^TM shield (and not wearing personal lead apron) during routine cardiac catheterization procedures (diagnostic and interventional). RE was measured at both thyroid and waist level with a real-time dosimetry system (Raysafe^TM , Billdal, Sweden), calculated on a median per case basis (mrems). Additional parameters collected included procedure type, access site, per case fluoroscopy time, and patient factors including body mass index.

RESULTS

In n=98 cases (25% diagnostic, 75% interventional including 22% chronic total occlusions), median/case RE was 0.4 mrems (thyroid) and 0.2 mrems (waist). RE=0 in 12 cases. In no case did radiation exposure exceed 3.2 mrems.

CONCLUSION

The Protego^TM shield system provides excellent RE protection to the Physician operator, without the need for personal lead aprons and has the potential to reduce catheterization laboratory occupational health hazards.

Discrete soft actor-critic with auto-encoder on vascular robotic system

Instrument delivery is critical part in vascular intervention surgery. Due to the soft-body structure of instruments, the relationship between manipulation commands and instrument motion is non-linear, making instrument delivery challenging and time-consuming. Reinforcement learning has the potential to learn manipulation skills and automate instrument delivery with enhanced success rates and reduced workload of physicians. However, due to the sample inefficiency when using high-dimensional images, existing reinforcement learning algorithms are limited on realistic vascular robotic systems. To alleviate this problem, this paper proposes discrete soft actor-critic with auto-encoder (DSAC-AE) that augments SAC-discrete with an auxiliary reconstruction task. The algorithm is applied with distributed sample collection and parameter update in a robot-assisted preclinical environment. Experimental results indicate that guidewire delivery can be automatically implemented after 50k sampling steps in less than 15 h, demonstrating the proposed algorithm has the great potential to learn manipulation skill for vascular robotic systems.

Effect of Different Anthropometric Body Indexes on Radiation Exposure in Patients Undergoing Cardiac Catheterisation and Percutaneous Coronary Intervention

Background: Patient factors, such as sex and body mass index (BMI), are known to influence patient radiation exposure. Body surface area (BSA) and its association with patient radiation exposure has not been well studied. Methods and Results: We analysed height, weight, BMI and BSA in consecutive patients undergoing cardiac catheterisation and percutaneous coronary intervention (PCI) at a high-volume Australian centre between September 2016 and April 2020 to assess their association with dose–area product (DAP, Gycm²). The mean age of the cohort was 64.5 ± 12.3 years with males comprising 68.8% (n = 8100, 5124 diagnostic cardiac catheterisation cases and 2976 PCI cases). Median male BMI was 28.4 kg/m² [IQR 25.2–32.1] versus 28.8 kg/m² [24.7–33.7] for females, p = 0.01. Males had higher BSA (2.0 ± 0.2 m²) than females (1.78 ± 0.2 m²), p = 0.001. Each 0.4 m² increase in BSA conferred a 1.32x fold change in DAP (95% CI 1.29–1.36, p ≤ 0.001). Each 5 kg/m² increase in BMI was linked to a 1.13x DAP fold change (1.12–1.14, p ≤ 0.001). Male sex conferred a 1.23x DAP fold change (1.20–1.26, p ≤ 0.001). Multivariable modelling with BMI or BSA explained 14% of DAP variance (R² 0.67 vs. 0.53 for both, p ≤ 0.001). Conclusions: BSA is an important anthropometric measure between the sexes and a key predictor of radiation dose and radiation exposure beyond sex, BMI, and weight.

Feasibility and Safety of Drug-Coated Balloon-Only Angioplasty for De Novo Ostial Lesions of the Left Anterior Descending Artery: Two-Center Retrospective Study

Introduction

There is limited evidence regarding the effectiveness of drug-coated balloon (DCB) angioplasty in the percutaneous treatment of complex de novo ostial coronary lesions. This study primarily aimed to explore the feasibility and safety of this innovative approach for ostial lesions in the left anterior descending artery (LAD).

Methods

Patients treated with paclitaxel DCB or second-generation drug-eluting stents (DES) were retrospectively enrolled from two large centers. The primary endpoints were major adverse cardiovascular events (MACE), including cardiovascular death, target lesion revascularization (TLR), target vessel revascularization, and recurrent myocardial infarction related to target artery occlusion. Cox regression analysis was used to identify risk factors for MACE, and propensity score matching was performed to minimize selection bias.

Results

A total of 388 patients were included; among them, 52 were treated with paclitaxel DCB, and 336 with DES for ostial LAD lesions. Using propensity score matching, 49 patients were treated with DCB-only and 49 with the DES strategy. The average follow-up time was 12 months; subsequently, a non-significant decrease in MACE rate was observed in the DCB-only angioplasty treatment group (MACE: 6 vs. 6%, p = 1.0; TLR: 2 vs. 4%, p = 0.56). Cox regression analysis indicated that DCB-only angioplasty was not an independent risk factor for adverse events after adjusting for confounding risk factors (hazard ratio: 1.713, p = 0.43).

Conclusion

The use of the DCB-only approach is an innovative and optional strategy in the treatment of isolated ostial LAD disease. A further randomized trial is of necessity to confirm the feasibility and safety of drug-coated balloon-only angioplasty for LAD de novo ostial lesions.

Robotic Percutaneous Coronary Intervention: The Good, the Bad, and What is to Come

The introduction of robots into healthcare has brought a wealth of opportunity for technical advancements, ranging from cleaning robots to disinfect hospital rooms to the high-tech surgical robots used in the operating room. Robotic-assisted percutaneous coronary intervention (R-PCI) has been a more recent development in the field, and is particularly revolutionary in that it serves to benefit the interventional cardiologist as well as the patient. Published data on R-PCI have shown its feasibility, safety, and more recently, its potential benefits. This review examines the current role of the robot in the catheterization laboratory, the authors’ experience with the most current generation of the robot, and what is yet to come.

BRAIN AND EYE AS POTENTIAL TARGETS FOR IONIZING RADIATION IMPACT: PART II - RADIATION CEREBRO/OPHTALMIC EFFECTS IN CHILDREN, PERSONS EXPOSED IN UTERO, ASTRONAUTS AND INTERVENTIONAL RADIOLOGISTS

BACKGROUND

Ionizing radiation (IR) can affect the brain and the visual organ even at low doses, while provoking cognitive, emotional, behavioral, and visual disorders. We proposed to consider the brain and the visual organ as potential targets for the influence of IR with the definition of cerebro-ophthalmic relationships as the «eye-brain axis».

OBJECTIVE

The present work is a narrative review of current experimental, epidemiological and clinical data on radiation cerebro-ophthalmic effects in children, individuals exposed in utero, astronauts and interventional radiologists.

MATERIALS AND METHODS

The review was performed according to PRISMA guidelines by searching the abstract and scientometric databases PubMed/MEDLINE, Scopus, Web of Science, Embase, PsycINFO, Google Scholar, published from 1998 to 2021, as well as the results of manual search of peer-reviewed publications.

RESULTS

Epidemiological data on the effects of low doses of IR on neurodevelopment are quite contradictory, while data on clinical, neuropsychological and neurophysiological on cognitive and cerebral disorders, especially in the left, dominant hemisphere of the brain, are nore consistent. Cataracts (congenital - after in utero irradiation) and retinal angiopathy are more common in prenatally-exposed people and children. Astronauts, who carry out longterm space missions outside the protection of the Earth's magnetosphere, will be exposed to galactic cosmic radiation (heavy ions, protons), which leads to cerebro-ophthalmic disorders, primarily cognitive and behavioral disorders and cataracts. Interventional radiologists are a special risk group for cerebro-ophthalmic pathology - cognitivedeficits, mainly due to dysfunction of the dominant and more radiosensitive left hemisphere of the brain, andcataracts, as well as early atherosclerosis and accelerated aging.

CONCLUSIONS

Results of current studies indicate the high radiosensitivity of the brain and eye in different contingents of irradiated persons. Further research is needed to clarify the nature of cerebro-ophthalmic disorders in different exposure scenarios, to determine the molecular biological mechanisms of these disorders, reliable dosimetric support and taking into account the influence of non-radiation risk factors.

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.

Design and Performance Evaluation of a Novel Vascular Robotic System for Complex Percutaneous Coronary Interventions

The robotic-assisted percutaneous coronary intervention is an emerging technology with great potential to solve the shortcomings of existing treatments. However, the current robotic systems can not manipulate two guidewires or ballons/stents simultaneously for coronary bifurcation lesions. This paper presents VasCure, a novel bio-inspired vascular robotic system, to deliver two guidewires and stents into the main branch and side branch of bifurcation lesions in sequence. The system is designed in master-slave architecture to reduce occupational hazards of radiation exposure and orthopedic injury to interventional surgeons. The slave delivery device has one active roller and two passive rollers to manipulate two interventional devices. The performance of the VasCure was verified by in vitro and in vivo animal experiments. In vitro results showed the robotic system has good accuracy to deliver guidewires and the maximum error is 0.38mm. In an animal experiment, the interventional surgeon delivered two guidewires and balloons to the left circumflex branch and the left anterior descending branch of the pig, which confirmed the feasibility of the vascular robotic system.

A Prospective Comparison of the Effects of Instrument Tracking on Time and Radiation During Minimally Invasive Lumbar Interbody Fusion

BACKGROUND

Minimally invasive surgical techniques have resulted in improved patient outcomes. One drawback has been the increased reliance on fluoroscopy and subsequent exposure to ionizing radiation. We have previously shown the efficacy of a novel instrument tracking system in cadaveric and preliminary clinical studies for commonplace orthopedic and spine procedures. In the present study, we examined the radiation and operative time using a novel instrument tracking system compared with standard C-arm fluoroscopy for patients undergoing minimally invasive lumbar fusion.

METHODS

The radiation emitted, number of radiographs taken, and time required to complete 2 tasks were recorded between the instrument tracking systems and conventional C-arm fluoroscopy. The studied tasks included placement of the initial dilator through Kambin's triangle during percutaneous lumbar interbody fusion and placement of pedicle screws during both percutaneous lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion with or without instrument tracking.

RESULTS

A total of 23 patients were included in the analysis encompassing 31 total levels. For the task of placing the initial dilator into Kambin's triangle, an average of 4.21 minutes (2.4 vs. 6.6 minutes; P = 0.002), 15 fluoroscopic images (5.4 vs. 20.5; P = 0.002), and 8.14 mGy (3.3 vs. 11.4; P = 0.011) were saved by instrument tracking. For pedicle screw insertion, an average of 5.69 minutes (3.97 vs. 9.67; P < 0.001), 14 radiographs (6.53 vs. 20.62; P < 0.001), and 7.89 mGy (2.98 vs. 10.87 mGy; P < 0.001) were saved per screw insertion.

CONCLUSIONS

Instrument tracking, when used for minimally invasive lumbar fusion, leads to significant reductions in radiation and operative time compared with conventional fluoroscopy.

Radiation-induced lens opacities: Epidemiological, clinical and experimental evidence, methodological issues, research gaps and strategy

In 2011, the International Commission on Radiological Protection (ICRP) recommended reducing the occupational equivalent dose limit for the lens of the eye from 150 mSv/year to 20 mSv/year, averaged over five years, with no single year exceeding 50 mSv. With this recommendation, several important assumptions were made, such as lack of dose rate effect, classification of cataracts as a tissue reaction with a dose threshold at 0.5 Gy, and progression of minor opacities into vision-impairing cataracts. However, although new dose thresholds and occupational dose limits have been set for radiation-induced cataract, ICRP clearly states that the recommendations are chiefly based on epidemiological evidence because there are a very small number of studies that provide explicit biological and mechanistic evidence at doses under 2 Gy. Since the release of the 2011 ICRP statement, the Multidisciplinary European Low Dose Initiative (MELODI) supported in April 2019 a scientific workshop that aimed to review epidemiological, clinical and biological evidence for radiation-induced cataracts. The purpose of this article is to present and discuss recent related epidemiological and clinical studies, ophthalmic examination techniques, biological and mechanistic knowledge, and to identify research gaps, towards the implementation of a research strategy for future studies on radiation-induced lens opacities. The authors recommend particularly to study the effect of ionizing radiation on the lens in the context of the wider, systemic effects, including in the retina, brain and other organs, and as such cataract is recommended to be studied as part of larger scale programs focused on multiple radiation health effects.

Catheter strategy to ease the procedure and reduce radiation exposure when requiring neck access

Objectives

To assess the potential occupational radiation reduction and technical feasibility in patients rotated 180° (upside-down) when requiring neck access for transcervical or trans-subclavian catheterisation.

Methods

Upside-down positioning is defined as rotating patients in supine position by 180°, so that the feet come to rest where the head would otherwise be. We retrospectively evaluated all these procedures performed between March 2016 and May 2019. Furthermore, two different phantoms (paediatric and adult) were used prospectively to quantify the occupational dose between conventional or upside-down positioning. In this context, ambient dose equivalents were measured using real-time dosimeters. Three different projection angles were applied.

Results

44 patients with median age and body weight of 1.0 year (range 0–56) and 9.5 kg (range 1.3–74.3) underwent 63 procedures positioned upside-down. This position proved advantageous for practical reasons, since the length of the examination table could be optimally used. Additionally, it resulted in a significantly lower overall ambient dose equivalent for the primary operator (PO) of 94.8% (mean: 2569±807 vs 135±23 nSv; p<0.01) in the adult, and of 65.5% (mean: 351±104 vs 121±56 nSv; p<0.01) in the paediatric phantom, respectively.

Conclusion

Upside-down positioning facilitates handling in a straightforward manner when access from the neck is required. Moreover, it significantly reduces local radiation exposure for the PO in the paediatric and, most impressively, in the adult phantom.

Patient Body Mass Index and Occupational Radiation Doses to Circulating Nurses During Coronary Angiography

BACKGROUND

Patient BMI is associated with radiation doses received by interventional cardiologists, yet the association between patient BMI and nurse radiation doses is unknown. This study evaluated the association between patient body mass index (BMI) and nurse radiation doses during coronary angiography.

METHODS

Nurse radiation doses were collected by real-time dosimeters during consecutive coronary angiography procedures and are reported as the personal dose equivalent (H_p10). Patient radiation doses were estimated using dose area product (DAP). Patient BMI was categorized in kg/m² as <25.0, 25.0-29.9, 30.0-34.9, 35.0-39.9, and ≥40. Multiple regression analysis determined procedural factors independently association with nurse radiation doses.

RESULTS

In 643 consecutive coronary angiography procedures, patient radiation doses increased significantly across increasing patient BMI categories (p < 0.001). Compared to a patient BMI <25, a patient BMI ≥40 was associated with a 2.3-fold increase in DAP (p < 0.001). Significant differences were also observed in nurse radiation doses across patient BMI categories (p = 0.036). Compared to a patient BMI <25, a patient BMI ≥40 was associated with a 4.0-fold increase in nurse radiation dose (BMI < 25: 0.3 [0.1, 1.3] μSv; BMI ≥ 40: 1.2 [0.2, 2.9] μSv; p = 0.003). By multiple regression analysis, each 1-unit kg/m² increase in patient BMI was associated with a 3.3% increase in nurse radiation dose (p = 0.002).

CONCLUSIONS

Patient BMI was significantly associated with nurse radiation doses during coronary angiography. These observations may have important implications on nurse radiation safety, especially in the setting of the ongoing obesity epidemic.

Combining Optimized Image Processing With Dual Axis Rotational Angiography: Toward Low-Dose Invasive Coronary Angiography

Background

Dual axis rotational coronary angiography (DARCA) reduces radiation exposure during coronary angiography on older x‐ray systems. The purpose of the current study is to quantify patient and staff radiation exposure using DARCA on a modality already equipped with dose‐reducing technology. Additionally, we assessed applicability of 1 dose area product to effective dose conversion factor for both DARCA and conventional coronary angiography (CCA) procedures.

Methods and Results

Twenty patients were examined using DARCA and were compared with 20 age‐, sex‐, and body mass index–matched patients selected from a prior study using CCA on the same x‐ray modality. All irradiation events are simulated using PCXMC (STUK, Finland) to determine organ and effective doses. Moreover, for DARCA each frame is simulated. Staff dose is measured using active personal dosimeters (DoseAware, Philips Healthcare, The Netherlands). With DARCA, median cumulative dose area product is reduced by 57% (ie, 7.41 versus 17.19 Gy·cm²). Effective dose conversion factors of CCA and DARCA are slightly different, yet this difference is not statistically significant. The occupational dose at physician's chest, leg, and collar level are reduced by 60%, 56%, and 16%, respectively, of which the first 2 reached statistical significance. Median effective dose is reduced from 4.75 mSv in CCA to 2.22 mSv in DARCA procedures, where the latter is further reduced to 1.79 mSv when excluding ventriculography.

Conclusions

During invasive coronary angiography, DARCA reduces radiation exposure even further toward low‐dose values on a system already equipped with advanced image processing and noise reduction algorithms. For both DARCA and CCA procedures, using 1 effective dose conversion factor of 0.30 mSv·Gy⁻¹·cm⁻² is feasible.

Effect of Instrument Navigation on C-arm Radiation and Time during Spinal Procedures: A Clinical Evaluation

Introduction

As minimally invasive spine surgery gains popularity, a focused effort must be made to reduce intraoperative radiation exposure to levels as low as reasonably achievable. Here, we demonstrate the clinical efficacy of a novel technology to aid in instrument navigation that aims to reduce intraoperative radiation exposure, number of fluoroscopic images, and time required to perform the most radiation intensive portions of a multitude of spinal procedures.

Methods

An internally randomized controlled study was performed over a 1-month period in order to clinically evaluate the effect of the C-arm assisted instrument tracking system, TrackX, on surgeon workflow, time, and radiation emitted. Three surgeons performed multiple spinal procedures on a total of 10 study patients and an additional 3 control patients. The surgeries encompassed minimally invasive spinal techniques and spanned extreme lateral interbody fusion, oblique lumbar interbody fusion, transforaminal lumbar interbody fusion along with percutaneous iliac screw placement, hardware removal, and kyphoplasty. The tasks studied included skin marking, first dilator insertion, localization for hardware placement and hardware removal.

Results

Overall radiation reduction was 83% (P < .0001). Overall reduction in x-rays taken was 78% (P < .0001). Overall time reduction was 81% (P = .0003). Statistical significance held for each surgeon studied and for nearly every procedure type. In these 10 study procedures, over 2 hours of overall operating room time was saved, all while requiring negligible set up time and no system calibration or supplementary x-rays to be taken. There were no adverse outcomes for any study patient, and there was no case where TrackX was not able to successfully complete a given portion of a procedure.

Conclusions

TrackX instrument navigation is a clinically efficacious and accurate instrument tracking modality. This is the first instrument navigational technology that reduces radiation exposure and images required to complete a procedure while decreasing operative time. TrackX thus allows increased surgical efficiency while increasing operative efficiency and improving intraoperative safety.

Level of Evidence

2.

Environmental and industrial developments in radiation cataractogenesis

Purpose: This review discusses recent developments in our understanding of biological and physiological mechanisms underlying radiation cataractogenesis. The areas discussed include effects of low-dose exposures to the lens including potential relevance of non-targeted effects, the development of new personal-protective equipment (PPE) and standards in clinical and nuclear settings motivated by the updated ICRP recommendations to mitigate exposures to the lens of the eye. The review also looks at evidence from the field linking cataracts in birds and mammals to low dose exposures.Conclusions: The review suggests that there is evidence that cataractogenesis is not a tissue reaction (deterministic effect) but rather is a low dose effect which shows a saturable dose response relationship similar to that seen for non-targeted effects in general. The review concludes that new research is needed to determine the dose response relationship in environmental studies where field data are contradictory and lab studies confined to rodent models for human exposure studies.

Radiation-Induced Cerebro-Ophthalmic Effects in Humans

Exposure to ionizing radiation (IR) could affect the human brain and eyes leading to both cognitive and visual impairments. The aim of this paper was to review and analyze the current literature, and to comment on the ensuing findings in the light of our personal contributions in this field. The review was carried out according to the PRISMA guidelines by searching PubMed, Scopus, Embase, PsycINFO and Google Scholar English papers published from January 2000 to January 2020. The results showed that prenatally or childhood-exposed individuals are a particular target group with a higher risk for possible radiation effects and neurodegenerative diseases. In adulthood and medical/interventional radiologists, the most frequent IR-induced ophthalmic effects include cataracts, glaucoma, optic neuropathy, retinopathy and angiopathy, sometimes associated with specific neurocognitive deficits. According to available information that eye alterations may induce or may be associated with brain dysfunctions and vice versa, we propose to label this relationship "eye-brain axis", as well as to deepen the diagnosis of eye pathologies as early and easily obtainable markers of possible low dose IR-induced brain damage.

Radiation protection in the cardiac catheterization laboratory

The trend towards more minimally invasive procedures in the past few decades has resulted in an exponential growth in fluoroscopy-guided catheter-based cardiology procedures. As these techniques are becoming more commonly used and developed, the adverse effects of radiation exposure to the patient, operator, and ancillary staff have been a subject of concern. Although occupational radiation dose limits are being monitored and seldom reached, exposure to chronic, low dose radiation has been shown to have harmful biological effects that are not readily apparent until years after. Given this, it is imperative that reducing radiation dose exposure in the cardiac catheterization laboratory remains a priority. Staff education and training, radiation dose monitoring, ensuring use of proper personal protective equipment, employment of shields, and various procedural techniques in minimizing radiation must always be diligently employed. Special care and consideration should be extended to pregnant women working in the cardiac catheterization laboratory. This review article presents a practical approach to radiation dose management and discusses best practice recommendations in the cardiac catheterization laboratory.

Occupational Doses to Medical Staff Performing or Assisting with Fluoroscopically Guided Interventional Procedures

Background Staff who perform fluoroscopically guided interventional (FGI) procedures are among the most highly radiation-exposed groups in medicine. However, there are limited data on monthly or annual doses (or dose trends over time) for these workers. Purpose To summarize occupational badge doses (lens dose equivalent and effective dose equivalent values) for medical staff performing or assisting with FGI procedures in 3 recent years after accounting for uninformative values and one- versus two-badge monitoring protocol. Materials and Methods Badge dose entries of medical workers believed to have performed or assisted with FGI procedures were retrospectively collected from the largest dosimetry provider in the United States for 49 991, 81 561, and 125 669 medical staff corresponding to years 2009, 2012, and 2015, respectively. Entries judged to be uninformative of occupational doses to FGI procedures staff were excluded. Monthly and annual occupational doses were described using summary statistics. Results After exclusions, 22.2% (153 033 of 687 912) of the two- and 32.9% (450 173 of 1 366 736) of the one-badge entries were judged to be informative. There were 335 225 and 916 563 of the two- and one-badge entries excluded, respectively, with minimal readings in the above-apron badge. Among the two-badge entries, 123 595 were incomplete and 76 059 had readings indicating incorrect wear of the badges. From 2009 to 2015 there was no change in lens dose equivalent values among workers who wore one badge (P = .96) or those who wore two badges (P = .23). Annual lens dose equivalents for workers wearing one badge (median, 6.9 mSv; interquartile range, 3.8213.8 mSv; n = 6218) were similar to those of staff wearing two badges (median, 7.1 mSv; interquartile range, 4.6-11.2 mSv; n = 1449) (P = .18), suggesting a similar radiation environment. Conclusion These workers are among the highest exposed to elevated levels of ionizing radiation, although their occupational doses are within U.S. regulatory limits. This is a population that requires consistent and accurate dose monitoring; however, failure to return one or both badges, reversal of badges, and improper badge placement are a major hindrance to this goal. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Karellas in this issue.

Is trans-radial approach related to an increased risk of radiation exposure in patients who underwent diagnostic coronary angiography or percutaneous coronary intervention? (The SAKARYA study)

OBJECTIVE

It is still debatable whether diagnostic coronary angiography (CA) or percutaneous coronary interventions (PCIs) increase radiation exposure when performed via radial approach as compared to femoral approach. This question was investigated in this study by comparison of dose-area product (DAP), reference air kerma (RAK), and fluoroscopy time (FT) among radial and femoral approaches.

METHODS

All coronary procedures between November 2015 and November 2017 were assessed; and 4215 coronary procedures were enrolled in the study. Patients with bifurcation, chronic total occlusion, cardiogenic shock, or prior coronary artery bypass surgery were excluded. These 4215 procedures were evaluated for three different categories: diagnostic CA (Group I), PCI in patients with stable angina (Group II), and PCI in patients with ACS (Group III).

RESULTS

Age was significantly higher in the femoral arm of all groups. Among patients in the radial arm of Groups I and II, males were over-represented. Therefore, a multiple linear regression analysis with stepwise method was performed. After adjusting these clinical confounders, there was no significant difference with regard to DAP, RAK, and FT between femoral and radial access in Group I. In contrast, PCI via radial access was significantly associated with increased DAP, RAK, and FT in Groups II and III.

CONCLUSION

In spite of an increased experience with trans-radial approach, PCI of coronary lesions via radial route was associated with a relatively small but significant radiation exposure in our study. Compared to femoral access, diagnostic CA via radial access was not related to an increased radiation exposure.

Effectiveness of additional X-ray protection devices in reducing Scattered radiation in radial interventions: protocol of the ESPRESSO randomised trial

BACKGROUND

A number of devices have been developed to minimise operator radiation exposure in the setting of cardiac catheterisation. The effectiveness of these devices has traditionally been explored in transfemoral coronary procedures; however, less is known for the transradial approach. We set out to examine the impact of three different radiation protection devices in a real-world setting.

METHODS AND DESIGN

Consecutive coronary diagnostic and intervention procedures are randomised in a 1:1:1 ratio to a shield-only protection (shield group), shield and overlapping 0.5 mm Pb panel curtain (curtain group) or shield, curtain and additional 75×40 cm, 0.5 mm Pb drape placed across the waist of the patient (drape group).The primary outcome is the difference in relative exposure of the primary operator among groups. Relative exposure is defined as the ratio between operator's exposure (E in μSv) and patient exposure (dose area product in cGy·cm²).

ETHICS AND DISSEMINATION

The protocol complies with good clinical practice and the ethical principles described in the Declaration of Helsinki and is approved by the local ethics committee. The results of the trial will be published as original article(s) in medical journals and/or as presentation at congresses.

TRIAL REGISTRATION NUMBER

NCT03634657.

Cataract risk in US radiologic technologists assisting with fluoroscopically guided interventional procedures: a retrospective cohort study

OBJECTIVES

To assess radiation exposure-related work history and risk of cataract and cataract surgery among radiologic technologists assisting with fluoroscopically guided interventional procedures (FGIP).

METHODS

This retrospective study included 35 751 radiologic technologists who reported being cataract-free at baseline (1994-1998) and completed a follow-up questionnaire (2013-2014). Frequencies of assisting with 21 types of FGIP and use of radiation protection equipment during five time periods (before 1970, 1970-1979, 1980-1989, 1990-1999, 2000-2009) were derived from an additional self-administered questionnaire in 2013-2014. Multivariable-adjusted relative risks (RRs) for self-reported cataract diagnosis and cataract surgery were estimated according to FGIP work history.

RESULTS

During follow-up, 9372 technologists reported incident physician-diagnosed cataract; 4278 of incident cases reported undergoing cataract surgery. Technologists who ever assisted with FGIP had increased risk for cataract compared with those who never assisted with FGIP (RR: 1.18, 95% CI 1.11 to 1.25). Risk increased with increasing cumulative number of FGIP; the RR for technologists who assisted with >5000 FGIP compared with those who never assisted was 1.38 (95% CI 1.24 to 1.53; p trend <0.001). These associations were more pronounced for FGIP when technologists were located ≤3 feet (≤0.9 m) from the patient compared with >3 feet (>0.9 m) (RRs for >5000 at ≤3 feet vs never FGIP were 1.48, 95% CI 1.27 to 1.74 and 1.15, 95% CI 0.98 to 1.35, respectively; pdifference=0.04). Similar risks, although not statistically significant, were observed for cataract surgery.

CONCLUSION

Technologists who reported assisting with FGIP, particularly high-volume FGIP within 3 feet of the patient, had increased risk of incident cataract. Additional investigation should evaluate estimated dose response and medically validated cataract type.

Transcatheter Atrial Septal Defect Closure in Children with and without Fluoroscopy: A Comparison

Objective

The aim of this study was to compare feasibility, effectiveness, safety, and outcome of atrial septal defect (ASD) device closure in children with and without fluoroscopy guidance.

Methods and Results

Children undergoing transcatheter ASD closure between 2002 and 2016 were included into this single center, retrospective study. Patients were analysed in two groups [1: intraprocedural fluoroscopy ± transoesophageal echocardiography (TOE) guidance; 2: TOE guidance alone]. Three-hundred-ninety-seven children were included, 238 (97 male) in group 1 and 159 (56 male) in group 2. Two-hundred-twenty-nine of 238 (96%) patients underwent successful fluoroscopy guided ASD closures versus 154/159 (97%) successful procedures with TOE guidance alone. Median weight (IQR) at intervention was 20kg (16.0-35.0) in group 1 versus 19.3kg (16.0-31.2) in group 2. Mean (SD) preinterventional ASD diameter was 12.4mm (4.4) in group 1 versus 12.2mm (3.9) in group 2. There was no significant difference in number of defects or characteristics of ASD rims. Median procedure time was shorter in group 2 [60min (47-86) versus 34min (28-44)]. Device-size-to-defect-ratio was similar in both groups [group 1: 1.07 versus group 2: 1.09]. There were less technical intraprocedural events in group 2 [10 (6.3%) versus 47 (20%)]. Intraprocedural complications were less frequent in group 2 [1 (0.6%) versus 8 (3.3%)].

Conclusion

Transcatheter ASD device closure with TOE guidance alone (i.e., without fluoroscopy) is as effective and safe as ASD closure with fluoroscopy guidance. As fluoroscopy remains an important adjunct to transoesophageal echocardiography, especially in complex defects and complications, procedures are always performed in a fully equipped cardiac catheterization laboratory.

Robotic-Assisted Percutaneous Coronary Intervention: Concept, Data, and Clinical Application

The occupational hazards for interventional cardiologists include the risk of cataracts, malignancy, and orthopedic injury. Robotic technology is now available with the introduction of platforms for performing percutaneous coronary and peripheral interventions. The original remote navigation system has evolved into the current CorPath robotic system, now approved for robotic-assisted cardiovascular interventions. The system removes the operator from the tableside and has been validated for safety, feasibility, and efficacy in coronary and peripheral vascular disease.

Usefulness of Pelvic Radiation Protection Shields During Transfemoral Procedures-Operator and Patient Considerations

Interventional cardiologists are increasingly exposed to radiation-induced hazards. The MAVIG shield is a lead-free drape and the RADPAD is a sterile, disposable, and lead-free shield, placed on the patient with the aim to minimize operator-received scatter radiation. The objective of the trial was to examine their efficacy in a real-world situation. We randomized 125 patients who underwent coronary procedures from the right femoral artery into 3 groups: Control group (n = 48 [39%]) without additional protection, MAVIG lead shield (n = 38 [30%]) and RADPAD shield (n = 39 [31%]). Multiple radiation dosimeters were used in each case. All 3 groups were with similar baseline and procedural characteristics. Fluoroscopy time and number of views were similar in all 3 study groups. Compared with the standard (no shield) protection [3.5 ± 5.57 mSv], the scatter radiation was reduced by a factor of 5 for the MAVIG group [0.46 ± 1.6 mSv and p = 0.001] and a factor of 4 for the RADPAD group [1.16 ± 2.29 mSv and p = 0.01]. The physician's radiation decreased with the 2 shields, but only the MAVIG shield showed statistically significant lower radiation: 0.49 ± 0.42 mSv in the standard group versus 0.26 ± 0.3 mSv in the MAVIG and 0.35 ± 0.44 mSv in the RADPAD (p = 0.135 for RADPAD and p = 0.005 for MAVIG). Patient's exposure was statistically similar to the control group. Although numerically there was an increase in radiation with the RADPAD and decrease with the MAVIG.

CONCLUSIONS

Our study found no statistically increase in patient radiation while the operator's radiation exposure was reduced. Decreasing scatter radiation can be done effectively using simple measurements and is of major importance.

X-ray canary in the cath lab: Posterior cataracts

Cataract formation in the posterior subcapsular region of the lens is a lesion highly specific to both high-dose acute radiation exposure and chronic low-dose exposure. Low-dose radiation may not manifest lens changes for several decades after initial exposure. Cardiac catheterization team members need to be educated on, and protected from, this form of radiation injury as its long latency period between exposure and physical damage may acutely reduce the sense of hazard amongst healthcare radiation workers.