Bonn call for action and the unfinished task of radiation protection of children and adolescents in low and middle-income countries: A focus on Sub-Saharan Africa

ObjectivesThe Bonn call for action, with the theme: “Setting the scene for the next decade,” was declared over nine years ago to strengthen radiation protection in medicine. This study reviews key actions and activities related to radiation protection of children and adolescents consistent with the Bonn call for action in sub-Saharan Africa to highlight progress and identify existing gaps.Key findingsA lot has happened since the declaration of the Bonn call-for-action such as a follow-up conference in 2017 on achieving change in the practice of radiation protection. However, there exists a huge gap that needs to be filled in the radiation protection of children and adolescents in low and middle-income countries particularly sub-Saharan Africa, where limited resources in health compete with radiation protection demands. Some of the gaps that remain are the apparent lack of implementation of the use of referral guidelines and establishment of national and regional diagnostic reference levels for paediatric imaging among others.ConclusionSeveral strides have been achieved on a global scale for the Bonn call for action, ranging from the justification of medical exposures to the current drive for radiation safety culture in medical imaging. However, several unmet needs for radiation protection for children and adolescents remain such as implementation of referral guidelines for justification and paediatric diagnostic reference levels.Implications for practiceStep up actions and close collaboration is required to strengthen the practice of paediatric radiation protection in low and middle-income countries because children account for a greater proportion of the population and are vulnerable to the negative effects of radiation like possible cancer induction.     

Assessment of the awareness of radiation protection and related concepts among nursing staff mainly working in diagnostic imaging units,cath-labs and operation theatres in Sri Lanka: A survey-based study

IntroductionThis study was carried out to evaluate the awareness of radiation protection, radiation types, medical imaging equipment and radiation effects among nurses for the first time in Sri Lanka. Since nurses are involved as direct caregivers in diagnostic and therapeutic radiography and radiation treatment procedures, they need to have a good understanding of the areas mentioned above.MethodsA self-administered questionnaire was used to collect data from 391 nurses working in hospitals, clinics, and other healthcare settings. Forwarded questions gathered the participants' demographic details and assessed their awareness of radiation protection, medical imaging equipment, radiation type and radiation effects. The average score per awareness area for each demographic characteristic was calculated based on the responses. Additionally, the percentage of participants who scored above 50 and 75 was calculated for each awareness area.ResultsThe majority were female participants (81.1%) and possessed a diploma in nursing (66.0%) with 10.8 years of average work experience. 92.3%, 74.7%, 69.8% and 22.3% of the participants scored more than 50 marks for the questions related to radiation protection, medical imaging equipment, radiation type and radiation effects, respectively. The level of nursing education and prior training in radiation protection significantly influenced all awareness areas, whereas participants with a graduate qualification in nursing and with prior radiation protection training scored the highest average marks.ConclusionBased on the scores obtained, the Sri Lankan nurses have satisfactory awareness of the essential concepts related to radiation types, medical imaging equipment and radiation protection. However, there is a significant lacking of awareness of radiation effects. This can be attributed to the fact that most participants did not have any formal training in radiation protection. The results implicate that proper training in radiation protection can significantly influence awareness of radiation protection and related concepts. Therefore, it is a timely requirement to initiate short awareness programs and continuing education programs on radiation protection for nurses working in specialised radiation units.Implications for practiceThe study suggests the necessity of initiating continuous education programs for nursing staff radiation protection to overcome the awareness gaps.     

Paediatric computed tomography radiation dose: A review of the global dilemma简

Computed tomography (CT) has earned a well-deserved role in diagnostic radiology, producing cross-sectional and three-dimensional images which permit enhanced diagnosis of many pathogenic processes. The speed, versatility, accuracy, and non-invasiveness of this procedure have resulted in a rapid increase in its use. CT imaging, however, delivers a substantially higher radiation dose than alternative imaging methodologies, particularly in children due to their smaller body dimensions. In addition, CT use in children produces an increased lifetime risk of cancer, as children’s developing organs and tissues are inherently more vulnerable to cellular damage than those of adults. Though individual risks are small, the increasing use of CT scans in children make this an important public health problem. Various organizations have recommended measures to minimize unnecessary exposures to radiation through CT scanning. These include elimination of multiple or medically unnecessary scans, development of patient-specific dosing guidelines, and use of alternative radiographic methodology wherever possible. Another important factor in excessive CT exposures, however, is a documented lack of awareness among medical practitioners of the doses involved in CT usage as well as its significant potential dangers. This review examines the effects of paediatric CT radiation, discusses the level of medical practitioner awareness of these effects, and offers recommendations on alternative diagnostic methods and practitioner education.     

Perception of Radiation Exposure and Risk Among Patients,Medical Students,and Referring Physicians at a Tertiary Care Community Hospital

Background

It is important for physicians to be aware of the radiation doses as well as the risks associated with diagnostic imaging procedures that they are ordering.

Methods

A survey was administered to patients, medical students, and referring physicians from a number of specialties to determine background knowledge regarding radiation exposure and risk associated with commonly ordered medical imaging tests.

Results

A total of 127 patients, 32 referring physicians, and 30 medical students completed the survey. The majority of patients (92%) were not informed of the radiation risks associated with tests that they were scheduled to receive and had false perceptions about the use of radiation and its associated risks. Physicians and medical students had misconceptions about the use of ionizing radiation in a number of radiologic examinations; for example, 25% and 43% of physicians and medical students, respectively, were unaware that interventional procedures used ionizing radiation, and 28% of physicians were unaware that mammography used ionizing radiation. Computed tomographies and barium studies were thought to be associated with the least ionizing radiation among physicians.

Conclusion

There is a need for educating the public, medical students, and referring physicians about radiation exposure and associated risk so that (1) patients receiving multiple medical imaging tests are aware of the radiation that they are receiving and (2) physicians and future physicians will make informed decisions when ordering such tests to limit the amount of radiation that patients receive and to promote informed consent among patients.     

Preliminary survey for communicating risk in medical exposure--perception of risk among nurses working in radiology

A questionnaire survey was conducted on radiation risk and medical exposure, particularly in applications involving children. The survey was targeted at nurses (170 females) engaged in important roles in communicating risk regarding medical exposure. The questionnaire survey yielded the following findings. 1) A significant number of respondents associated the word "radiation" with "cancer treatment," "exposure," and "X-ray pictures." Perceptions about "food exposure" differed between respondents with children and those without. 2) Among the potential health problems posed by radiation, "effects on children," "cancer and leukemia," and "genetic effects" were perceived as the most worrisome. Significant differences in perception were noted regarding infertility between respondents with children and those without. 3) Concerning the effects of medical exposure on fetuses/children, only 10 percent of all respondents replied that they were not anxious about negative effects in either case. Among the respondents who felt uneasy about these aspects, most tended to assess exposed parts, doses, damage potentially suffered, timing of occurrence, and uncertainty, based on their professional experience and knowledge, to rationally distinguish acceptable risks from unacceptable ones and to limit concern to the unacceptable aspects.     

Radiation, thoracic imaging, and children: radiation safety

The chest is the most frequently evaluated region of the body in children. The majority of thoracic diagnostic imaging, namely "conventional" radiography (film screen, computed radiography and direct/digital radiography), fluoroscopy and angiography, and computed tomography, depends on ionizing radiation. Since errors, oversights, and inattention to radiation exposure continue to be extremely visible issue for radiology in the public eye it is incumbent on the imaging community to maximize the yield and minimize both the real and potential radiation risks with diagnostic imaging. Technical (e.g. equipment and technique) strategies can reduce exposure risk and improve study quality, but these must be matched with efforts to optimize appropriate utilization for safe and effective healthcare in thoracic imaging in children. To these ends, material in this chapter will review practice patterns, dose measures and modality doses, radiation biology and risks, and radiation risk reduction strategies for thoracic imaging in children.     

Current issues and actions in radiation protection of patients

Medical application of ionizing radiation is a massive and increasing activity globally. While the use of ionizing radiation in medicine brings tremendous benefits to the global population, the associated risks due to stochastic and deterministic effects make it necessary to protect patients from potential harm. Current issues in radiation protection of patients include not only the rapidly increasing collective dose to the global population from medical exposure, but also that a substantial percentage of diagnostic imaging examinations are unnecessary, and the cumulative dose to individuals from medical exposure is growing. In addition to this, continued reports on deterministic injuries from safety related events in the medical use of ionizing radiation are raising awareness on the necessity for accident prevention measures. The International Atomic Energy Agency is engaged in several activities to reverse the negative trends of these current issues, including improvement of the justification process, the tracking of radiation history of individual patients, shared learning of safety significant events, and the use of comprehensive quality audits in the clinical environment.     

加强放射诊断辐射剂量管理的必要性及应对策略

近年来, 我国放射诊断检查特别是CT检查的频次迅猛增加, 已经成为国民人均辐射剂量的最大人工辐射来源, 并有可能超过天然辐射源的贡献。临床诊疗活动中, 患者和受检者短时间内可能进行多项目、多频次的放射诊断成像, 所接受的累积辐射剂量较高, 甚至一天检查的剂量贡献超过50或100 mSv, 从而对其健康产生潜在风险。因此, 有必要对放射诊断辐射剂量信息进行统计分析与控制管理, 以尽可能降低过高剂量及其辐射危险的发生概率。本文对放射诊断辐射风险的国际认识、我国放射诊断设备和检查频次、放射诊断辐射剂量及其管理现状进行阐述, 并就辐射剂量的管理提出应对策略, 为进一步推进临床实践中的辐射防护提供参考。     

Radiation exposure and mortality risk from CT and PET imaging of patients with malignant lymphoma

Objective

To quantify radiation exposure and mortality risk from computed tomography (CT) and positron emission tomography (PET) imaging with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) in patients with malignant lymphoma (Hodgkin’s disease [HD] or non-Hodgkin’s lymphoma [NHL]).

Methods

First, organ doses were assessed for a typical diagnostic work-up in children with HD and adults with NHL. Subsequently, life tables were constructed for assessment of radiation risks, also taking into account the disease-related mortality.

Results

In children with HD, cumulative effective dose from medical imaging ranged from 66?mSv (newborn) to 113?mSv (15 years old). In adults with NHL the cumulative effective dose from medical imaging was 97?mSv. Average fractions of radiation-induced deaths for children with HD [without correction for disease-related mortality in brackets] were 0.4% [0.6%] for boys and 0.7% [1.1%] for girls, and for adults with NHL 0.07% [0.28%] for men and 0.09% [0.37%] for women.

Conclusion

Taking into account the disease-related reduction in life expectancy of patients with malignant lymphoma results in a higher overall mortality but substantial lower incidence of radiation induced deaths. The modest radiation risk that results from imaging with CT and ¹⁸F-FDG PET can be considered as justified, but imaging should be performed with care, especially in children.

Key Points

• Survival of malignant lymphoma has improved dramatically over the past decades.
• PET and CT currently play important roles for malignant lymphoma patients.
• The potential hazard of ionising radiation has become an increasingly important issue.
• When assessing radiation risks, disease-related reduction in life expectancy should be considered.
• CT and ¹⁸ F-FDG PET create a modest radiation-induced mortality risk.

     

Radiation exposure in X-ray-based imaging techniques used in osteoporosis

Recent advances in medical X-ray imaging have enabled the development of new techniques capable of assessing not only bone quantity but also structure. This article provides (a) a brief review of the current X-ray methods used for quantitative assessment of the skeleton, (b) data on the levels of radiation exposure associated with these methods and (c) information about radiation safety issues. Radiation doses associated with dual-energy X-ray absorptiometry are very low. However, as with any X-ray imaging technique, each particular examination must always be clinically justified. When an examination is justified, the emphasis must be on dose optimisation of imaging protocols. Dose optimisation is more important for paediatric examinations because children are more vulnerable to radiation than adults. Methods based on multi-detector CT (MDCT) are associated with higher radiation doses. New 3D volumetric hip and spine quantitative computed tomography (QCT) techniques and high-resolution MDCT for evaluation of bone structure deliver doses to patients from 1 to 3 mSv. Low-dose protocols are needed to reduce radiation exposure from these methods and minimise associated health risks.     

Radiation protection of medical staff

The continuing increase in the worldwide use of X-ray imaging has implications for radiation protection of medical staff. Much of the increased usage could be viewed as simply a workload issue with no particular new challenges. However, advances in technology and developments in techniques have seen an increase in the number of X-ray procedures in which medical personnel need to maintain close physical contact with the patient during radiation exposures. The complexity of many procedures means the potential for significant occupational exposure is high, and appropriate steps must be taken to ensure that actual occupational exposures are as low as reasonably achievable. Further attention to eye protection may be necessitated if a lowering of the dose limit for the lens of the eye is implemented in the near future.Education and training in radiation protection as it applies to specific situations, established working procedures, availability and use of appropriate protective tools, and an effective monitoring programme are all essential elements in ensuring that medical personnel in X-ray imaging are adequately and acceptably protected.     

Evaluating the distribution of research in radiation sciences as published in general medical physics journals

Introduction

The aim of this study was to evaluate the distribution and trends of studies in different areas of medical physics science. This assessment can reflect the past and current status of the field, and it can also predict the future of this science.

Principles of the International Commission on Radiological Protection system of dose limitation

The current recommendations of the International Commission on Radiological Protection (ICRP), published in 1977, identify two types of effect against which protection is required. "Stochastic" effects are those for which the probability of an effect occurring, rather than its severity, is regarded as a function of dose without threshold, whereas "non-stochastic" effects are those for which the severity varies with the dose and for which a threshold may occur. The system of dose limitation recommended by the ICRP is based on the prevention of non-stochastic effects and limitation of the probability of stochastic effects to levels deemed to be acceptable. The prevention of non-stochastic effects is achieved by setting dose-equivalent limits at values such that no threshold dose would be reached, even following exposure for the whole of a lifetime or for the total period of a working life. The limitation of stochastic effects is achieved by keeping all justifiable exposures as low as is reasonably achievable, economic and social factors being taken into account, subject to the constraint that reductions in collective exposure do not cause unacceptably large individual exposures. The formulation of a quantitative system of dose limitation based on these principles requires that judgments be made on several factors including: relationships between radiation dose and the induction of deleterious effects for a variety of endpoints and radiation types; acceptable levels of risk for radiation workers and members of the public; and methods of assessing whether the cost of introducing protective measures is justified by the reduction in radiation detriment which they will provide. In the case of patients deliberately exposed to ionising radiations, the objectives of radiation protection differ somewhat from those applying to radiation workers and members of the public. For patients, risks and benefits relate to the same person and upper limits on acceptable risks may differ grossly from those appropriate to normal individuals. For these reasons, and because of its historical relationship with the International Congress of Radiology, the ICRP has given special consideration to radiation protection in medicine and has published reports on protection of the patient in diagnostic radiology and in radiation therapy.     

How reliable are the risk estimates for X-ray examinations in forensic age estimations? A safety update

Possible biological side effects of exposure to X-rays are stochastic effects such as carcinogenesis and genetic alterations. In recent years, a number of new studies have been published about the special cancer risk that children may suffer from diagnostic X-rays. Children and adolescents who constitute many of the probands in forensic age-estimation proceedings are considerably more sensitive to the carcinogenic risks of ionizing radiation than adults. Established doses for X-ray examinations in forensic age estimations vary from less than 0.1 μSv (left hand X-ray) up to more than 800 μSv (computed tomography). Computed tomography in children, as a relatively high-dose procedure, is of particular interest because the doses involved are near to the lower limit of the doses observed and analyzed in A-bombing survivor studies. From these studies, direct epidemiological data exist concerning the lifetime cancer risk. Since there is no medical indication for forensic age examinations, it should be stressed that only safe methods are generally acceptable. This paper reviews current knowledge on cancer risks associated with diagnostic radiation and aims to help forensic experts, dentists, and pediatricians evaluate the risk from radiation when using X-rays in age-estimation procedures.     

Recent international regulations: low dose-low rate radiation protection and the demise of reason

The radiation protection measures suggested by the International Committee for Radiation Protection (ICRP), national regulating bodies and experts, have been becoming ever more strict despite the decrease of any information supporting the existence of the Linear no Threshold model (LNT) and of any adverse effects of Low Dose Low Rate (LDLR) irradiation. This tendency arises from the disproportionate response of human society to hazards that are currently in fashion and is unreasonable. The 1 mSv/year dose limit for the public suggested by the ICRP corresponds to a 1/18,181 detriment-adjusted cancer risk and is much lower than other hazards that are faced by modern societies such as e.g. driving and smoking which carry corresponding rate risks of 1/2,100 and 1/2,000. Even worldwide deadly work accidents rate is higher at 1/ 8,065. Such excessive safety measures against minimal risks from man made radiation sources divert resources from very real and much greater hazards. In addition they undermine research and development of radiation technology and tend to subjugate science and the quest for understanding nature to phobic practices.     

Clinical radiation management for fluoroscopically guided interventional procedures

The primary goal of radiation management in interventional radiology is to minimize the unnecessary use of radiation. Clinical radiation management minimizes radiation risk to the patient without increasing other risks, such as procedural risks. A number of factors are considered when estimating the likelihood and severity of patient radiation effects. These include demographic factors, medical history factors, and procedure factors. Important aspects of the patient's medical history include coexisting diseases and genetic factors, medication use, radiation history, and pregnancy. As appropriate, these are evaluated as part of the preprocedure patient evaluation; radiation risk to the patient is considered along with other procedural risks. Dose optimization is possible through appropriate use of the basic features of interventional fluoroscopic equipment and intelligent use of dose-reducing technology. For all fluoroscopically guided interventional procedures, it is good practice to monitor radiation dose throughout the procedure and record it in the patient's medical record. Patients who have received a clinically significant radiation dose should be followed up after the procedure for possible deterministic effects. The authors recommend including radiation management as part of the departmental quality assurance program.     

Radiologie und Schwangerschaft

In a radiology department there are frequently asked questions associated with pregnant and breast feeding women. These are related to either pregnant patients or staff members or the questions are centered on the fetus as a patient. For pregnant patients the potential exposure to the mother and the fetus related to the imaging modality selected as well as the effects of the necessary contrast media must be taken into account. Even for methods without ionizing radiation possible limitations in the use for pregnant women must be discussed. Finally, this medical check defines the imaging modality and the necessary protocol and contrast media. The present article describes the legal requirements in Germany, the technical exposure and pharmacological risks for the pregnant woman and the fetus regarding imaging modalities with and without ionizing radiation. The forthcoming second article will address the risk analysis for examinations with ionizing radiation and will present recommendations for typical clinical imaging problems.     

Radiology and pregnancy. Principles, general requirements and exposure

In a radiology department there are frequently asked questions associated with pregnant and breast feeding women. These are related to either pregnant patients or staff members or the questions are centered on the fetus as a patient. For pregnant patients the potential exposure to the mother and the fetus related to the imaging modality selected as well as the effects of the necessary contrast media must be taken into account. Even for methods without ionizing radiation possible limitations in the use for pregnant women must be discussed. Finally, this medical check defines the imaging modality and the necessary protocol and contrast media. The present article describes the legal requirements in Germany, the technical exposure and pharmacological risks for the pregnant woman and the fetus regarding imaging modalities with and without ionizing radiation. The forthcoming second article will address the risk analysis for examinations with ionizing radiation and will present recommendations for typical clinical imaging problems.     

Perception of radiation hazards

The health risks of radiation have been carefully studied and are relatively well understood in comparison with other risks to the human environment. Public perception of these risks often is distorted, due in part to lack of familiarity with the actual risk levels involved. There is a need for dissemination to the public of accurate information on radiation risks as well as to patients and volunteer subjects for studies involving radiation exposures. Often such information can be presented meaningfully by comparing the risks of radiation exposure with other, more familiar risks. Natural background radiation is a universally present and generally accepted source of risk, and thus serves as one reference against which to compare the risks of other radiation exposures. Natural background radiation averages about 100 mrem/yr, but much higher levels are encountered in some parts of the US (400 mrem/yr) and worldwide (2,000 mrem/yr). These variations are due primarily to differences in cosmic ray intensity with altitude and in terrestrial radiation originating from soil and rocks. Radiation risks also may be compared with the risks of other human activities, both voluntary and involuntary. The former are useful for comparisons with the risks of voluntary radiation exposures such as occupational exposure and participation in medical or research procedures involving radiation. Involuntary radiation exposure, such as might result from the transportation and disposal of radioactive waste, poses a more complicated issue. Comparisons of such exposures to natural background radiation levels and their variations are helpful. Two other concepts that have been proposed for assessing the relative risk of low-level radiation exposure are "de minimus risk" and "probability of causation." The former suggests that there is some minimal level of involuntary risk that can be considered acceptable, provided it carries with it some benefit to society or the individual. The latter is a concept that has been introduced in legislation to decide compensation for alleged injuries from radiation exposures.