The biological effects of diagnostic cardiac imaging on chronically exposed physicians: the importance of being non-ionizing

Low-dose pulsed vs standard pulsed fluoroscopy during ERCP to reduce radiation without change in image quality: Prospective randomized study

Background and study aims Endoscopic retrograde cholangiopancreatography (ERCP) poses the risk of radiation exposure (RE) to patients and staff and increases the risk of adverse biological effects such as cataracts, sterility, and cancer. Newer fluoroscopy equipment (C-Arm) provides options to limit radiation in the form of lower radiation dose and frame rate or time-limited "pulsed" settings. However, the impact of lower settings on image quality has not been assessed, and no standard protocol exists for fluoroscopy settings used during ERCP. Patients and methods This was a single-center, double-blind, prospective randomized study of consecutive adult patients undergoing standard-of-care ERCP at a tertiary academic medical center. Patients were randomized into two groups: 1) standard-dose pulsed and 2) low-dose pulsed. Pulsed mode (8 fps) was defined as x-ray exposure either in the manufacturer standard-dose or low-dose settings limited to 3 seconds each time the foot-operated switch was depressed. Results Seventy-eight patients undergoing ERCP were enrolled and randomized. No difference in age, gender, or body mass index was found between the two groups. No significant difference in image quality was found between standard-dose and low-dose fluoroscopy P = 0.925). The low-dose group was exposed to significantly less radiation when compared with standard-dose P < 0.05). Fluoroscopy time (minutes) was similar in both groups (2.0 vs 1.9), further suggesting that group assignment had no impact on image quality or procedure time. Conclusions Low-dose pulsed fluoroscopy is a reliable method that substantially reduces radiation without compromising image quality or affecting procedure or fluoroscopy times. This underscores the need for standardization in ERCP fluoroscopy settings to limit radiation exposure.

Bystander Effect of Therapeutic Ultrasound in the Presence of Cisplatin: An in Vitro Study on Human Melanoma Cells

Background

In the bystander effect, non-irradiated cells receive biological signals from adjacent irradiated cells and undergo a variety of alterations, considered recently in non-ionizing irradiation like ultrasound waves. In this study, the bystander effect of therapeutic ultrasound exposure alone and in combination with cisplatin was determined.

Objective

This study aims to determine the bystander effect caused by ultrasound and cisplatin.

Material and Methods

This experimental study was conducted on the human melanoma cell line including two groups of target and bystander cells. The target cell group was divided into three sub-groups of ultrasound irradiation alone, cisplatin alone, and ultrasound irradiation in the presence of cisplatin that the culture medium of these three groups of cells was transferred to the bystander cell group using the medium transfer technique. Then, apoptotic bystander cells and the expression of P53 and HO-1 in target and bystander groups were measured.

Results

The results of the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and apoptosis assay showed that cell death in target and bystander groups receiving the ultrasound with cisplatin is higher than in the ultrasound without cisplatin. PCR (the polymerase chain reaction) results in the target and bystander groups receiving treatments with increased expression of the P53 gene. Target and bystander groups receiving the ultrasound without cisplatin showed a decrease in HO-1 gene expression, while the ultrasound with cisplatin showed an increase in the HO-1 gene compared to the control group.

Conclusion

Combining ultrasound with ultrasound and without it can transfer bystander signals to the cells that are not directly treated.

Advances in TEE-Centric Intraprocedural Multimodal Image Guidance for Congenital and Structural Heart Disease

Percutaneous interventions are gaining rapid acceptance in cardiology and revolutionizing the treatment of structural heart disease (SHD). As new percutaneous procedures of SHD are being developed, their associated complexity and anatomical variability demand a high-resolution special understanding for intraprocedural image guidance. During the last decade, three-dimensional (3D) transesophageal echocardiography (TEE) has become one of the most accessed imaging methods for structural interventions. Although 3D-TEE can assess cardiac structures and functions in real-time, its limitations (e.g., limited field of view, image quality at a large depth, etc.) must be addressed for its universal adaptation, as well as to improve the quality of its imaging and interventions. This review aims to present the role of TEE in the intraprocedural guidance of percutaneous structural interventions. We also focus on the current and future developments required in a multimodal image integration process when using TEE to enhance the management of congenital and SHD treatments.

Frame-rate reduction to reduce radiation dose for cardiac device implantation is safe

Background

Radiation exposure to patient and surgeon during cardiac implantable electrical device (CIED) procedures remains a substantial health hazard to date. Advanced technical options for radiation dose reduction often pose considerable financial hurdles. We propose a near-zero cost, low-effort modification to a clinical x-ray system significantly reducing radiation dose during CIED implantation.

Objective

We aim to evaluate a reduced frame rate protocol in CIED implantation for complication rates and reduction in radiation exposure.

Methods

Starting May 2019, the frame rate during CIED implantations at our hospital was halved from 7.5 frames/s to 3.8 frames/s, and no further technical changes were made. During the following year, 264 patients were operated using this protocol and retrospectively compared with 231 cases implanted in the year before the protocol change, totaling 495 cases. Of these, 17%, 63%, and 19% were single-chamber, dual-chamber, or resynchronization devices, respectively. Incidence of complication prior to hospital discharge was considered the primary endpoint of the analysis. Radiation dose and procedural parameters were secondary endpoints.

Results

There was no increase in complications with the reduced frame rate protocol. Regression analysis further supported that the reduced frame rate radiation protocol was not associated with complication rates. Radiation exposure measured as dose area product was significantly reduced by ∼62% (median 369 [interquartile range 154-1207] cGy·cm² via the reduced frame rate protocol vs median 970 [interquartile range 400-1906] cGy·cm² with the standard frame rate; P < 0.01).

Conclusion

A reduction of frame rate during CIED implantation is safe in terms of complication incidence and effective in terms of reducing radiation exposure.

Possible Effects on Health of Ultrasound Exposure, Risk Factors in the Work Environment and Occupational Safety Review

Ultrasonic waves are mechanical waves with a frequency greater than 20,000 Hz. Ultrasonic waves are emitted by devices that are used in industry or that have a medical or aesthetic purpose. There is growing interest in the effect of ultrasound absorption on the human body, since people's exposure to these acoustic waves has increased considerably in recent years. There are more and more devices that emit ultrasounds used for different sanitary procedures, aesthetic treatments and industrial processes, creating more possibilities of ultrasound noise, and therefore an increased risk of occupational hazard and occupational danger. Experiments on animals have shown damage to internal organs from receiving different ultrasonic frequencies. The main task of this work was to organize and summarize recent studies on ultrasound to reflect the current state of this technique and establish a systematic basis for future lines of research. This work has allowed us to better understand the unknown field of these high frequencies of sound, and highlights the need to carry out more studies on the ultrasound emissions that can be absorbed by the human body to determine how this energy could affect humans by calculating the maximum dose of exposure and developing manuals for the use of ultrasound-emitting equipment to protect the health of workers and all people. It is necessary to develop regulations by public administrations to improve the protection of workers, health professionals, patients and all people in general for better occupational safety, indoor environmental quality and environmental health.

Integrated Circuits for Medical Ultrasound Applications: Imaging and Beyond

Medical ultrasound has become a crucial part of modern society and continues to play a vital role in the diagnosis and treatment of illnesses. Over the past decades, the development of medical ultrasound has seen extraordinary progress as a result of the tremendous research advances in microelectronics, transducer technology and signal processing algorithms. However, medical ultrasound still faces many challenges including power-efficient driving of transducers, low-noise recording of ultrasound echoes, effective beamforming in a non-linear, high-attenuation medium (human tissues) and reduced overall form factor. This paper provides a comprehensive review of the design of integrated circuits for medical ultrasound applications. The most important and ubiquitous modules in a medical ultrasound system are addressed, i) transducer driving circuit, ii) low-noise amplifier, iii) beamforming circuit and iv) analog-digital converter. Within each ultrasound module, some representative research highlights are described followed by a comparison of the state-of-the-art. This paper concludes with a discussion and recommendations for future research directions.

Radiation exposure to the eyes and thyroid during C-arm fluoroscopy-guided cervical epidural injections is far below the safety limit

Background

The aim of this study was to evaluate radiation exposure to the eye and thyroid in pain physicians during the fluoroscopy-guided cervical epidural block (CEB).

Methods

Two pain physicians (a fellow and a professor) who regularly performed C-arm fluoroscopy-guided CEBs were included. Seven dosimeters were used to measure radiation exposure, five of which were placed on the physician (forehead, inside and outside of the thyroid protector, and inside and outside of the lead apron) and two were used as controls. Patient age, sex, height, and weight were noted, as were radiation exposure time, absorbed radiation dose, and distance from the X-ray field center to the physician.

Results

One hundred CEB procedures using C-arm fluoroscopy were performed on comparable patients. Only the distance from the X-ray field center to the physician was significantly different between the two physicians (fellow: 37.5 ± 2.1 cm, professor: 41.2 ± 3.6 cm, P = 0.03). The use of lead-based protection effectively decreased the absorbed radiation dose by up to 35%.

Conclusions

Although there was no difference in radiation exposure between the professor and the fellow, there was a difference in the distance from the X-ray field during the CEBs. Further, radiation exposure can be minimized if proper protection (thyroid protector, leaded apron, and eyewear) is used, even if the distance between the X-ray beam and the pain physician is small. Damage from frequent, low-dose radiation exposure is not yet fully understood. Therefore, safety measures, including lead-based protection, should always be enforced.

Radiation safety education and compliance with safety procedures-The Korea Nurses' Health Study

AIMS AND OBJECTIVES

To examine the current state of radiation safety education and its influence on nurses' compliance with safety procedures.

BACKGROUND

Use of radiation in therapy and diagnosis has prolonged and improved millions of lives, but it presents potential hazards for healthcare professionals.

DESIGN

A cross-sectional design.

METHODS

Participants included 1,672 female nurses of childbearing age who had recently been exposed to radiation-emitting generators or radiation. Quantitative data were taken from the Korea Nurses' Health Study, the Korean version of the Nurses' Health Study conducted in the USA. Confounding variables included sociodemographic factors, duration of employment in a department where work involved radiation, hospital's geographical location, bed size and hospital safety climate. Statistical analyses included descriptive statistics, Spearman's correlation coefficients and multivariable ordinal logistic regression.

RESULTS

Half (50.3%) of nurses received no safety training, whereas the other half received some safety training as follows: only once (14.4%), irregularly (10.2%) and regularly (25.1%). Of the six radioactive safety compliance questionnaires, 29.4%, 20.2%, 30.7% and 19.7% complied to none, one, two and more than three, respectively. After controlling for confounding variables, relative to that observed with no safety education, irregular education that occurred more than twice (OR = 1.597, CI = 1.177-2.164) and regular education (OR = 2.223, CI = 1.770-2.792) increased the likelihood that nurses would comply with safety procedures.

CONCLUSIONS

Low levels of safety education and adherence raise critical concerns regarding nurses' well-being. As routine safety education increases safety adherence, healthcare managers and policymakers should emphasise regular safety education.

RELEVANCE TO CLINICAL PRACTICE

Radiation safety education for nurses and their compliance with safety procedures have seldom been discussed in South Korea. However, as nurses' safety is directly related to the quality of patient care, additional safety education should be provided for hospital nurses to minimise their occupational exposure to harmful radioactive substances in clinical settings.

Poly(ADP-Ribose) Glycohydrolase (PARG) Silencing Suppresses Benzo(a)pyrene Induced Cell Transformation

Benzo(a)pyrene (BaP) is a ubiquitously distributed environmental pollutant and known carcinogen, which can induce malignant transformation in rodent and human cells. Poly(ADP-ribose) glycohydrolase (PARG), the primary enzyme that catalyzes the degradation of poly(ADP-ribose) (PAR), has been known to play an important role in regulating DNA damage repair and maintaining genomic stability. Although PARG has been shown to be a downstream effector of BaP, the role of PARG in BaP induced carcinogenesis remains unclear. In this study, we used the PARG-deficient human bronchial epithelial cell line (shPARG) as a model to examine how PARG contributed to the carcinogenesis induced by chronic BaP exposure under various concentrations (0, 10, 20 and 40 μM). Our results showed that PARG silencing dramatically reduced DNA damages, chromosome abnormalities, and micronuclei formations in the PARG-deficient human bronchial epithelial cells compared to the control cells (16HBE cells). Meanwhile, the wound healing assay showed that PARG silencing significantly inhibited BaP-induced cell migration. Furthermore, silencing of PARG significantly reduced the volume and weight of tumors in Balb/c nude mice injected with BaP induced transformed human bronchial epithelial cells. This was the first study that reported evidences to support an oncogenic role of PARG in BaP induced carcinogenesis, which provided a new perspective for our understanding in BaP exposure induced cancer.

Inactivation of Enterobacter aerogenes in reconstituted skim milk by high- and low-frequency ultrasound

The inactivation of Enterobacter aerogenes in skim milk using low-frequency (20kHz) and high-frequency (850kHz) ultrasonication was investigated. It was found that low-frequency acoustic cavitation resulted in lethal damage to E. aerogenes. The bacteria were more sensitive to ultrasound in water than in reconstituted skim milk having different protein concentrations. However, high-frequency ultrasound was not able to inactivate E. aerogenes in milk even when powers as high as 50W for 60min were used. This study also showed that high-frequency ultrasonication had no influence on the viscosity and particle size of skim milk, whereas low-frequency ultrasonication resulted in the decrease in viscosity and particle size of milk. The decrease in particle size is believed to be due to the breakup of the fat globules, and possibly to the cleavage of the κ-casein present at the surface of the casein micelles. Whey proteins were also found to be slightly affected by low-frequency ultrasound, with the amounts of α-lactalbumin and β-lactoglobulin slightly decreasing.

Academic training in radiation safety awareness and practice among Iranian residents/fellows

OBJECTIVE

To determine the current state of radiation safety awareness and practice among Iranian radiology/cardiology residents.

METHODS

In this cross-sectional study, 725 Iranian cardiology/radiology fellows/residents (685 residents and 40 fellows) were studied. Radiation safety awareness and practice were assessed using a 13-item survey questionnaire. Based on academic trainings provided in their medical centres, the subjects were divided into two groups (trained vs untrained).

RESULTS

Trained residents/fellows had better performance compared with untrained ones regarding awareness of radiation dealing instructions, knowing safety experts of their centres (43.8% vs 20.1%, p<0.001) and their contact information (38.4% vs 11.4%, p<0.001), date of the last CBC (complete blood count) checking (15.1% vs 2.5%, p<0.001), use of lead glass (61.6% vs 41.8%, p=0.003), apron (94.5% vs 90%, p=0.016) and radiation shield (71.2% vs 46.2%, p<0.001).

CONCLUSIONS

Awareness/practice of Iranian cardiology/radiology residents/fellows about radiation exposure safety issues is not acceptable currently. Those who received formal training courses at their academic centres about the safety measures had significantly better knowledge compared with those who did not. It is suggested that radiation safety training be offered at the beginning of residency/fellowship for residents/fellows in a comprehensive and uniform way throughout medical universities.

Radiation Exposure of the Hand and Chest during C-arm Fluoroscopy-Guided Procedures

BACKGROUND

The C-arm fluoroscope is an essential tool for the intervention of pain. The aim of this study was to investigate the radiation exposure experienced by the hand and chest of pain physicians during C-arm fluoroscopy-guided procedures.

METHODS

This is a prospective study about radiation exposure to physicians during transforaminal epidural steroid injection (TFESI) and medial branch block (MBB). Four pain physicians were involved in this study. Data about effective dose (ED) at each physician's right hand and left side of the chest, exposure time, radiation absorbed dose (RAD), and the distance from the center of the X-ray field to the physician during X-ray scanning were collected.

RESULTS

Three hundred and fifteen cases were included for this study. Demographic data showed no significant differences among the physicians in the TFESIs and MBBs. In the TFESI group, there was a significant difference between the ED at the hand and chest in all the physicians. In physician A, B and C, the ED at the chest was more than the ED at the hand. The distance from the center of the X-ray field to physician A was more than that of the other physicians, and for the exposure time, the ED and RAD in physician A was less than that of the other physicians. In the MBB group, there was no difference in the ED at the hand and chest, except for physician D. The distance from the center of the X-ray field to physician A was more than that of the other physicians and the exposure time in physician A was less than that of the other physicians.

CONCLUSIONS

In conclusion, the distance from the radiation source, position of the hand, experience and technique can correlate with the radiation dose.

Radiation safety and education in the applicants of the final test for the expert of pain medicine

Background

The C-arm fluoroscope is known as the most important equipment in pain interventions. This study was conducted to investigate the completion rate of education on radiation safety, the knowledge of radiation exposure, the use of radiation protection, and so on.

Methods

Unsigned questionnaires were collected from the 27 pain physicians who applied for the final test to become an expert in pain medicine in 2011. The survey was composed of 12 questions about the position of the hospital, the kind of hospital, the use of C-arm fluoroscopy, radiation safety education, knowledge of annual permissible radiation dose, use of radiation protection, and efforts to reduce radiation exposure.

Results

In this study, although most respondents (93%) had used C-arm fluoroscopy, only 33% of the physicians completed radiation safety education. Even though nine (33%) had received education on radiation safety, none of the physicians knew the annual permissible radiation dose. In comparing the radiation safety education group and the no-education group, the rate of wearing radiation-protective glasses or goggles and the use of radiation badges or dosimeters were significantly higher in the education group. However, in the use of other protective equipment, knowledge of radiation safety, and efforts to reduce radiation exposure, there were no statistical differences between the two groups.

Conclusions

The respondents knew very little about radiation safety and had low interest in their radiation exposure. To make the use of fluoroscopy safer, additional education, as well as attention to and knowledge of practices of radiation safety are required for pain physicians.

Long-term results of the percutaneous transhepatic venoplasty of portal vein stenoses after pediatric liver transplantation

  This paper has the objective to evaluate retrospectively the long-term results of transhepatic treatment of PV stenoses after pediatric LT. During an eight-yr period, 15 children with PV stenoses underwent PTA with balloon dilation or stent placement in case of PTA failure after LT. Patients' body weights ranged from 9.3 to 46kg (mean, 15.5kg). PV patency was evaluated in the balloon dilation and in the stent placement groups. Technical and clinical successes were achieved in all cases with no complication. Eleven patients (11/15; 73.3%) were successfully treated by single balloon dilation. Four patients (4/15; 26.7%) needed stent placement. One patient was submitted to stent placement during the same procedure because of PTA failure. The other three developed clinical signs of portal hypertension because of PV restenoses two, eight, and twenty-eight months after the first PTA. They had to be submitted to a new procedure with stent placement. The follow-up time ranged from 3 to 8.1 yr (mean, 6.3 yr). In conclusion, transhepatic treatment of PV stenoses after pediatric LT with balloon dilation or stent placement demonstrated to be a safe and effective treatment that results in long-term patency.

SCAI consensus document on occupational radiation exposure to the pregnant cardiologist and technical personnel

Concerns regarding radiation exposure and its effects during pregnancy are often quoted as an important barrier preventing many women from pursuing a career in Interventional Cardiology. Finding the true risk of radiation exposure from performing cardiac catheterisation procedures can be challenging and guidelines for pregnancy exposure have been inadequate. The Women in Innovations group of Cardiologists with endorsement of the Society for Cardiovascular Angiography and Interventions aim to provide guidance in this publication by describing the risk of radiation exposure to pregnant physicians and cardiac catheterisation personnel, to educate on appropriate radiation monitoring and to encourage mechanisms to reduce radiation exposure. Current data do not suggest a significant increased risk to the foetus of pregnant women in the cardiac catheterisation laboratory and thus do not justify precluding pregnant physicians from performing procedures in the cardiac catheterisation laboratory. However, radiation exposure amongst pregnant physicians should be properly monitored and adequate radiation safety measures are still warranted.

Acute and chronic radiation injury

INTRODUCTION

Although all areas of the body are susceptible to radiation injury, different tissues have varying tolerances for radiation exposure. The goal of this summary is to introduce basic concepts of radiation biology and discuss the effects of radiation on various tissues.

METHODS

Reference texts and literature were reviewed to summarize key points in radiation biology and the direct and indirect cell damage caused by radiation.

RESULTS

The most prevalent factor for injury is long exposure time, which can be an issue in lengthy peripheral vascular or aortic interventions. Several key maneuvers can help decrease exposure for both the patient and the physician.

CONCLUSION

Radiation induces tissue injury at the cellular level. The use of good fluoroscopic technique is imperative for physician and patient protection.

Radiation safety among cardiology fellows

Cardiology fellows can be exposed to high radiation levels during procedures. Proper radiation training and implementation of safety procedures is of critical importance in lowering physician health risks associated with radiation exposure. Participants were cardiology fellows in the United States (n = 2,545) who were contacted by e-mail to complete an anonymous survey regarding the knowledge and practice of radiation protection during catheterization laboratory procedures. An on-line survey engine, SurveyMonkey, was used to distribute and collect the results of the 10-question survey. The response rate was 10.5%. Of the 267 respondents, 82% had undergone formal radiation safety training. Only 58% of the fellows were aware of their hospital's pregnancy radiation policy and 60% knew how to contact the hospital's radiation safety officer. Although 52% of the fellows always wore a dosimeter, 81% did not know their level of radiation exposure in the previous year and only 74% of fellows knew the safe levels of radiation exposure. The fellows who had received formal training were more likely to be aware of their pregnancy policy, to know the contact information of their radiation safety officer, to be aware of the safe levels of radiation exposure, to use dosimeters and RadPad consistently, and to know their own level of radiation exposure in the previous year. In conclusion, cardiology fellows have not been adequately educated about radiation safety. A concerted effort directed at physician safety in the workplace from the regulatory committees overseeing cardiology fellowships should be encouraged.

Health risk and biological effects of cardiac ionising imaging: from epidemiology to genes

Cardiac diagnostic or therapeutic testing is an essential tool for diagnosis and treatment of cardiovascular disease, but it also involves considerable exposure to ionizing radiation. Every exposure produces a corresponding increase in cancer risk, and risks are highest for radiation exposure during infancy and adolescence. Recent studies on chromosomal biomarkers corroborate the current radioprotection assumption showing that even modest radiation load due to cardiac catheter-based fluoroscopic procedures can damage the DNA of the cell. In this article, we review the biological and clinical risks of cardiac imaging employing ionizing radiation. We also discuss the perspectives offered by the use of molecular biomarkers in order to better assess the long-term development of health effects.

Cancer risk from professional exposure in staff working in cardiac catheterization laboratory: insights from the National Research Council's Biological Effects of Ionizing Radiation VII Report

BACKGROUND

Occupational doses from fluoroscopy-guided interventional procedures are the highest ones registered among medical staff using x-rays. The aim of the present study was to evaluate the order of magnitude of cancer risk caused by professional radiation exposure in modern invasive cardiology practice.

METHODS

From the dosimetric Tuscany Health Physics data bank of 2006, we selected dosimetric data of the 26 (7 women, 19 men; age 46 +/- 9 years) workers of the cardiovascular catheterization laboratory with effective dose >2 mSv. Effective dose (E) was expressed in milliSievert, calculated from personal dose equivalent registered by the thermoluminescent dosimeter, at waist or chest, under the apron, according to the recommendations of National Council of Radiation Protection. Lifetime attributable risk of cancer was estimated using the approach of Biological Effects of Ionizing Radiation 2006 report VII.

RESULTS

Cardiac catheterization laboratory staff represented 67% of the 6 workers with yearly exposure >6 mSv. Of the 26 workers with 2006 exposure >2 mSv, 15 of them had complete records of at least 10 (up to 25) consecutive years. For these 15 subjects having a more complete lifetime dosimetric history, the median individual effective dose was 46 mSv (interquartile range = 24-64). The median risk of (fatal and nonfatal) cancer (Biological Effects of Ionizing Radiation 2006) was 1 in 192 (interquartile range = 1 in 137-1 in 370).

CONCLUSIONS

Cumulative professional radiological exposure is associated with a non-negligible Lifetime attributable risk of cancer for the most exposed contemporary cardiac catheterization laboratory staff.

Sex proportion of offspring and exposure to radiation in male invasive cardiologists

High radiation exposure among male radiologists has been reported to result in a significantly higher proportion of female offspring. This study examined whether work-related radiation exposure was associated with a higher propensity for female offspring among male interventional cardiologists. On behalf of the interventional committee of the Society for Cardiovascular Angiography and Interventions, an Internet-based questionnaire was sent to the society's 2063 members. The 402 male respondents had a total of 518 biological offspring; 48.6% of them were female. Among the 172 high-volume male diagnostic operators (those who performed >300 cases annually), there were 218 biological offspring, of whom 46.8% were female. Among the 59 high-volume male interventional operators, there were 70 biological offspring, of whom 45.7% were female. P values were nonsignificant for all three groups. In conclusion, work-related radiation exposure of male invasive and interventional cardiologists was not associated with a statistically significant preponderance of female offspring.

Acute chromosomal DNA damage in human lymphocytes after radiation exposure in invasive cardiovascular procedures

AIMS

We evaluated whether radiation exposure during interventional cardiovascular procedures can induce damage to deoxyribonucleic acid (DNA).

METHODS AND RESULTS

Micronucleus assay (MN) was performed as biomarker of chromosomal damage and intermediate endpoint in carcinogenesis. Seventy-two patients (54 males, age = 63.8 +/- 10.5 years) undergoing a wide range of radiation exposure during invasive cardiovascular procedures (coronary angiography, n = 9; percutaneous coronary intervention, n = 9; peripheral transluminal angioplasty, n = 37; and cardiac resynchronization therapy, n = 17) were enrolled. MN frequency was evaluated before, 2, and 24 h after the radiation exposure. Dose-area product (DAP; Gy cm(2)) was assessed as physical measure of radiation load. DAP value was 96.0 +/- 63.9 Gy cm(2). MN frequency was 15.1 +/- 7.1 per thousand at baseline and showed a significant rise at 2 h (17.5 +/- 6.5 per thousand, P = 0.03) and 24 h (18.5 +/- 7.3 per thousand, P = 0.004) after procedures.

CONCLUSION

Our results corroborate the current radioprotection assumption that even modest radiation load can damage the DNA of the cell and induce chromosome alterations which are early predictors of increased cancer risk.

Cardiac imaging: The biological effects of diagnostic cardiac ultrasound

Diagnostic cardiac ultrasounds are an environment-friendly and non-ionising imaging technology. However, ultrasounds are not biologically inert, and their use might have profound clinical impact. This paper summarizes the known effects of cardiac ultrasound--compared to other major imaging techniques--to exposed patients and to clinically exposed physicians practising ultrasound imaging. Furthermore, this review also provides an overview of the evidences on the biological effects of diagnostic ultrasound--which suggest that ultrasound with frequency, intensity and duration fully in the diagnostic range have significant molecular, cellular and organ effects. A better understanding of these effects may improve our understanding of the complex interactions between ultrasound and biological tissues and may open new avenues to therapeutic applications based on the ultrasound-modulated cell functions, such as membrane transduction, apoptosis, cell permeability and thrombolysis.

Radiation dose exposure during cardiac and peripheral arteries catheterisation

BACKGROUND

Ionising radiation carries an oncogenic risk which is linearly related to the dose. An estimation of the effective dose can be obtained from the measurements of the dose-area product (DAP), which is a measure of stochastic risk and a potential quality indicator.

AIM

To assess radiation exposure of patients in a large volume cardiac cath-lab.

METHODS

A retrospective analysis of adult cardiac and peripheral percutaneous procedures (April to December 2004) was carried out to determine the DAP and estimated risk of malignancy. We identified 6 groups: Group 1 (n=100, coronary angiography and ventriculography); Group 2 (n=50, carotid stenting); Group 3 (n=50, aortography+coronary angiography+ventriculography); Group 4 (n=100, inferior extremities angiography+predilatation and stenting); Group 5 (n=100, coronary angiography+ventriculography+direct coronary stenting); Group 6 (n=100, coronary angiography+ventriculography+coronary predilation and stenting). Dose-area product meter attached on the X-ray unit was used for the estimation of the radiation dose received by the patient during the procedures.

RESULTS

DAP values (mean+/-S.D.) ranged from 41+/-30 Gy cm2 in Group 1 (lowest) to 118+/-89 Gy cm2 in Group 6 (highest). Within each group, individual radiation exposure varies substantially: from 11 to 200 Gy cm2 in Group 1, and from 30 to 733 Gy cm2 in Group 6 patients. Average exposure in a Group 6 patient corresponds to a risk of mortality from a malignancy of about 1 in 1000.

CONCLUSION

The radiation dose varies substantially across different types of procedures and up to tenfold within the same procedure. The enhanced knowledge of radiation dose might help the cardiologist to implement radiation sparing procedures eventually minimizing patient and operator radiation hazards in invasive cardiology.

Somatic DNA damage in interventional cardiologists: a case-control study

Interventional cardiologists who work in cardiac catheterization laboratories are exposed to low doses of ionizing radiation that could pose a health hazard. DNA damage is considered to be the main initiating event by which radiation damage to cells results in development of cancer and hereditary disease. The aim of the present study was to assess the effects of chronic low-dose X-ray radiation exposure on somatic DNA damage of interventional cardiologists working in high-volume cardiac catheterization laboratories. For this analysis, we used peripheral lymphocytes and the assay for micronuclei (MNs), which is considered to be a reliable biological dosimeter for radiation exposure. We obtained peripheral blood from 62 physicians (mean age+/-se = 40.6+/-1.5 years): 31 interventional cardiologists (group I, exposed) and 31 age- and sex-matched clinical cardiologists (group II, nonexposed). Interventional cardiologists showed higher MN values (group I=20.5+/-1.6 vs. group II=12.8+/-1.3, P=0.001), although some overlap was apparent in the individual subject analysis. A correlation between years of professional activity and MN frequency value was detectable for interventional cardiologists (r=0.428, P=0.02) but not for clinical cardiologists (r=0.253, P=0.17). The results indicated that, overall, interventional cardiologists working in a high-volume catheterization laboratory have higher levels of somatic DNA damage when compared with clinical cardiologists working outside the catheterization laboratory. The amount of this damage varies and is only weakly related to the duration of professional exposure, which suggests that a dominant modulation of the underlying genetic substrate by environmental factors has a role in determining the harm in individual physicians.