The system of radiological protection and the UN sustainable development goals.

In 2015 the United Nations issued 17 Sustainable Development Goals (SDGs) addressing a wide range of global social, economic, and environmental challenges. The main goal of this paper is to provide an understanding of how the current System of Radiological Protection relates to these SDGs. In the first part it is proposed that the current System of Radiological Protection is implicitly linked to sustainable development. This is substantiated by analysing the features of the current System as set out by the International Commission on Radiological Protection (ICRP) in its publications. In the second part it is proposed that sustainability should be considered and more explicitly addressed in the next ICRP general recommendations, as part of the currently ongoing review and revision of the current System. A few examples are given of how this could be realised, and it is proposed that this issue should be discussed and developed together with the international community interested in radiological protection.

Vancouver call for action to strengthen expertise in radiological protection worldwide.

Ionising radiation has been used for over a century for peaceful purposes, revolutionising health care and promoting well-being through its application in industry, science, and medicine. For almost as long, the International Commission on Radiological Protection (ICRP) has promoted understanding of health and environmental risks of ionising radiation and developed a protection system that enables the safe use of ionising radiation in justified and beneficial practices, providing protection from all sources of radiation. However, we are concerned that a shortage of investment in training, education, research, and infrastructure seen in many sectors and countries may compromise society's ability to properly manage radiation risks, leading to unjustified exposure to or unwarranted fear of radiation, impacting the physical, mental, and social well-being of our peoples. This could unduly limit the potential for research and development in new radiation technologies (healthcare, energy, and the environment) for beneficial purposes. ICRP therefore calls for action to strengthen expertise in radiological protection worldwide through: (1) National governments and funding agencies strengthening resources for radiological protection research allocated by governments and international organisations, (2) National research laboratories and other institutions launching and sustaining long-term research programmes, (3) Universities developing undergraduate and graduate university programmes and making students aware of job opportunities in radiation-related fields, (4) Using plain language when interacting with the public and decision makers about radiological protection, and (5) Fostering general awareness of proper uses of radiation and radiological protection through education and training of information multipliers. The draft call was discussed with international organisations in formal relations with ICRP in October 2022 at the European Radiation Protection Week in Estoril, Portugal, and the final call announced at the 6th International Symposium on the System of Radiological Protection of ICRP in November 2022 in Vancouver, Canada.

Summary of the 2021 ICRP workshop on the future of radiological protection.

The International Commission on Radiological Protection (ICRP) has embarked on a process to review and revise the current System of Radiological Protection ('the System'). To stimulate discussion, the ICRP published two open-access articles: one on aspects of the System that might require review, and another on research that might improve the scientific foundation of the System. Building on these articles, the ICRP organized a Workshop on the Future of Radiological Protection as an opportunity to engage in the review and revision of the System. This digital workshop took place from 14 October-3 November 2021 and included 20 live-streamed and 43 on-demand presentations. Approximately 1500 individuals from 100 countries participated. Based on the subjects covered by the presentations, this summary is organized into four broad areas: the scientific basis, concepts and application of the System; and the role of the ICRP. Some of the key topics that emerged included the following: classification of radiation-induced effects; adverse outcome pathway methodologies; better understanding of the dose-response relationship; holistic and reasonable approaches to optimization of protection; radiological protection of the environment; ethical basis of the System; clarity, consistency and communication of the System; application of the System in medicine and application of the principles of justification and optimization of protection.

Areas of research to support the system of radiological protection.

This document presents the ICRP's updated vision on "Areas of Research to Support the System of Radiological Protection", which have been previously published in 2017. It aims to complement the research priorities promoted by other relevant international organisations, with the specificity of placing them in the perspective of the evolution of the System of Radiological Protection. This document contributes to the process launched by ICRP to review and revise the System of Radiological Protection that will update the 2007 General Recommendations in ICRP Publication 103.

Keeping the ICRP recommendations fit for purpose.

The International Commission on Radiological Protection (ICRP) has embarked on a review and revision of the system of Radiological Protection that will update the 2007 general recommendations in ICRPPublication 103. This is the beginning of a process that will take several years, involving open and transparent engagement with organisations and individuals around the world. While the system is robust and has performed well, it must adapt to address changes in science and society to remain fit for purpose. The aim of this paper is to encourage discussions on which areas of the system might gain the greatest benefit from review, and to initiate collaborative efforts. Increased clarity and consistency are high priorities. The better the system is understood, the more effectively it can be applied, resulting in improved protection and increased harmonisation. Many areas are identified for potential review including: classification of effects, with particular focus on tissue reactions; reformulation of detriment, potentially including non-cancer diseases; re-evaluation of the relationship between detriment and effective dose, and the possibility of defining detriments for males and females of different ages; individual variation in the response to radiation exposure; heritable effects; and effects and risks in non-human biota and ecosystems. Some of the basic concepts are also being considered, including the framework for bringing together protection of people and the environment, incremental improvements to the fundamental principles of justification and optimisation, a broader approach to protection of individuals, and clarification of the exposure situations introduced in 2007. In addition, ICRP is considering identifying where explicit incorporation of the ethical basis of the system would be beneficial, how to better reflect the importance of communications and stakeholder involvement, and further advice on education and training. ICRP invites responses on these and other areas relating to the review of the System of Radiological Protection.

Individual response of humans to ionising radiation: governing factors and importance for radiological protection.

Tissue reactions and stochastic effects after exposure to ionising radiation are variable between individuals but the factors and mechanisms governing individual responses are not well understood. Individual responses can be measured at different levels of biological organization and using different endpoints following varying doses of radiation, including: cancers, non-cancer diseases and mortality in the whole organism; normal tissue reactions after exposures; and, cellular endpoints such as chromosomal damage and molecular alterations. There is no doubt that many factors influence the responses of people to radiation to different degrees. In addition to the obvious general factors of radiation quality, dose, dose rate and the tissue (sub)volume irradiated, recognized and potential determining factors include age, sex, life style (e.g., smoking, diet, possibly body mass index), environmental factors, genetics and epigenetics, stochastic distribution of cellular events, and systemic comorbidities such as diabetes or viral infections. Genetic factors are commonly thought to be a substantial contributor to individual response to radiation. Apart from a small number of rare monogenic diseases such as ataxia telangiectasia, the inheritance of an abnormally responsive phenotype among a population of healthy individuals does not follow a classical Mendelian inheritance pattern. Rather it is considered to be a multi-factorial, complex trait.

Quantitative assessment of chronic lung disease of infancy using computed tomography.

The aims of this study were to determine whether infants and toddlers with chronic lung disease of infancy (CLDI) have smaller airways and lower lung density compared with full-term healthy controls. Multi-slice computed tomography (CT) chest scans were obtained at elevated lung volumes during a brief respiratory pause in sedated infants and toddlers; 38 CLDI were compared with 39 full-term controls. For CLDI subjects, gestational age at birth ranged from 25 to 29 weeks. Airway size was measured for the trachea and the next three to four generations into the right lower lobe; lung volumes and tissue density were also measured. The relationship between airway size and airway generation differed between the CLDI and full-term groups; the sizes of the first and second airway generations were larger in the shorter CLDI than in the shorter full-term subjects. The increased size in the airways in the CLDI subjects was associated with increasing mechanical ventilation time in the neonatal period. CLDI subjects had a greater heterogeneity of lung density compared with full-term subjects. Our results indicate that quantitative analysis of multi-slice CT scans at elevated volumes provides important insights into the pulmonary pathology of infants and toddlers with CLDI.

Radiological protection of the patient in veterinary medicine and the role of ICRP.

At the request of the Main Commission of the International Commission on Radiological Protection (ICRP), Task Group 107 (TG107) was set up to consider the issue of radiological protection of the patient in veterinary medicine. TG107, who authored this article, brought together information relating to the use of diagnostic imaging and radiation oncology in veterinary medicine. A number of specific areas were identified that appeared to be appropriate for attention by ICRP. These included the use of dose quantities and units, the need for re-evaluation of stochastic and deterministic risks from ionising radiation in animals, and the growing use of imaging and therapeutic equipment for animals that is little different from that available to humans. TG107 unanimously recommended that it was both appropriate and timely for ICRP to consider and advise on these issues, and the Main Commission agreed. This paper summarises the findings of TG107.

Ethical aspects in the use of radiation in medicine: update from ICRP Task Group 109.

Whereas scientific evidence is the basis for recommendations and guidance on radiological protection, professional ethics is critically important and should always guide professional behaviour. The International Commission on Radiological Protection (ICRP) established Task Group 109 to advise medical professionals, patients, families, carers, the public, and authorities about the ethical aspects of radiological protection of patients in the diagnostic and therapeutic use of radiation in medicine. Occupational exposures and research-related exposures are not within the scope of this task group. Task Group 109 will produce a report that will be available to the different interested parties for consultation before publication. Presently, the report is at the stage of a working document that has benefitted from an international workshop organised on the topic by the World Health Organization. It presents the history of ethics in medicine in ICRP, and explains why this subject is important, and the benefits it can bring to the standard biomedical ethics. As risk is an essential part in decision-making and communication, a summary is included on what is known about the dose-effect relationship, with emphasis on the associated uncertainties. Once this theoretical framework has been presented, the report becomes resolutely more practical. First, it proposes an evaluation method to analyse specific situations from an ethical point of view. This method allows stakeholders to review a set of six ethical values and provides hints on how they could be balanced. Next, various situations (e.g. pregnancy, elderly, paediatric, end of life) are considered in two steps: first within a realistic, ethically challenging scenario on which the evaluation method is applied; and second within a more general context. Scenarios are presented and discussed with attention to specific patient circumstances, and on how and which reflections on ethical values can be of help in the decision-making process. Finally, two important related aspects are considered: how should we communicate with patients, family, and other stakeholders; and how should we incorporate ethics into the education and training of medical professionals?

Lung structure and function of infants with recurrent wheeze when asymptomatic.

Infants with recurrent wheeze have repeated episodes of airways obstruction; however, relatively little is known about the structure and function of their lungs when not symptomatic. The current authors evaluated whether infants with recurrent wheeze have smaller airway lumens or thickened airway walls, as well as decreased airway function. High-resolution computed tomography images 1 mm thick were obtained at three anatomic locations at an elevated lung volume and at functional residual capacity. Forced expiratory flows were also measured in subjects with recurrent wheeze. Airway lumen, wall areas and lung tissue density were not significantly different for recurrent wheeze (n = 17) and control (n = 14) subjects; however, subjects with recurrent wheeze had lower forced expiratory flows than predicted. Similar findings were obtained when subjects were grouped by exposure to tobacco smoke. These findings indicate that infants with recurrent wheeze, as well as exposure to tobacco smoke, have lower airway function when not symptomatic. The lower forced expiratory flows may result from a degree of airway narrowing that could not be resolved with the methodology employed or from other mechanisms, such as more collapsible airways or decreased pulmonary elastic recoil.

Noncontrast Head CT in Children: National Variation in Radiation Dose Indices in the United States.

BACKGROUND AND PURPOSE: Radiologists should manage the radiation dose for pediatric patients to maintain reasonable diagnostic confidence. We assessed the variation in estimated radiation dose indices for pediatric noncontrast head CT in the United States. MATERIALS AND METHODS: Radiation dose indices for single-phase noncontrast head CT examinations in patients 18 years of age and younger were retrospectively reviewed between July 2011 and June 2016 using the American College of Radiology CT Dose Index Registry. We used the reported volume CT dose index stratified by patient demographics and imaging facility characteristics. RESULTS: The registry included 295,296 single-phase pediatric noncontrast head CT studies from 1571 facilities (56% in male patients and 53% in children older than 10 years of age). The median volume CT dose index was 33 mGy (interquartile range = 22-47 mGy). The volume CT dose index increased as age increased. The volume CT dose index was lower in children's hospitals (median, 26 mGy) versus academic hospitals (median, 32 mGy) and community hospitals (median, 40 mGy). There was a lower volume CT dose index in level I and II trauma centers (median, 27 and 32 mGy, respectively) versus nontrauma centers (median, 40 mGy) and facilities in metropolitan locations (median, 30 mGy) versus those in suburban and rural locations (median, 41 mGy). CONCLUSIONS: Considerable variation in the radiation dose index for pediatric head CT exists. Median dose indices and practice variations at pediatric facilities were both lower compared with other practice settings. Decreasing dose variability through proper management of CT parameters in pediatric populations using benchmarks generated by data from registries can potentially decrease population exposure to ionizing radiation.

In vitro migration of lymphocytes through collagen matrix: arrested locomotion in tumor-infiltrating lymphocytes.

Antitumor immunity requires (a) extravasation of lymphocytes from the blood stream to interstitium, (b) locomotion through extracellular matrix to the site of the tumor, (c) effector cell recognition of the tumor target with cell/cell contact and binding of adhesion receptors, (d) T-cell receptor binding to histocompatibility and tumor antigens, and (e) tumor cell lysis. We hypothesize that the tumor microenvironment inhibits lymphocyte locomotion through extracellular matrix as one mechanism by which tumors may avert host defense. Lymphocyte locomotion was investigated in vitro using a three-dimensional collagen gel model. Fresh tumor-infiltrating lymphocytes (TIL) were obtained by enzymatic digestion of melanomas and renal cell carcinoma, and mononuclear cells were isolated by discontinuous Ficoll-Hypaque gradient. The lymphocytes were analyzed for motility from a point of origin between basal and overlay layers of collagen gel. Results showed that TIL migration was almost completely inhibited, compared with migration of normal and cancer patient peripheral blood leukocytes and lymphocytes from lymph nodes. Short-term (24-h) exposure of lymphocytes to cytokines during the assay in the collagen gel matrix had no effect on locomotor ability. Long-term (19, 30, or 35 days) culture of TIL in 200 units/ml of interleukin 2 reinstated locomotor ability. Short-term exposure of any of the lymphocyte populations to interleukin 1-alpha, interleukin 1-beta, interleukin 2, interleukin 3, interleukin 4, alpha-interferon, or gamma-interferon had no effect on migration. Thus, TIL display a uniquely arrested ability to locomote through collagen gel. Inhibition of the locomotion of infiltrating effector cells is possibly a mechanism by which the tumor evades the host immune system.

Internet-based ICRP resource for healthcare providers on the risks and benefits of medical imaging that uses ionising radiation.

The purpose of the International Commission on Radiological Protection (ICRP) Committee 3 Working Party was to update the 2001 web-based module 'Radiation and your patient: a guide for medical practitioners' from ICRP. The key elements of this task were: to clearly identify the target audience (such as healthcare providers with an emphasis on primary care); to review other reputable sources of information; and to succinctly publish the contribution made by ICRP to the various topics. A 'question-and-answer' format addressing practical topics was adopted. These topics included benefits and risks of imaging using ionising radiation in common medical situations, as well as pertaining to specific populations such as pregnant, breast-feeding, and paediatric patients. In general, the benefits of medical imaging and related procedures far outweigh the potential risks associated with ionising radiation exposure. However, it is still important to ensure that the examinations are clinically justified, that the procedure is optimised to deliver the lowest dose commensurate with the medical purpose, and that consideration is given to diagnostic reference levels for particular classes of examinations.

Atypical manifestations of two cases of trisomy 9 syndrome: rethinking development delay.

Trisomy 9 syndrome is characterized by "bulbous" nose, microphthalmia, dislocated limbs, and other anomalies of skeletal, cardiac, genitourinary, and central nervous systems. With the exception of one reported case study, all surviving infants have had severe mental impairment. The prospect of severe mental retardation often overwhelms parents who are faced with prenatal diagnosis of trisomy 9. We report on two new cases of mosaic trisomy 9, both of whom are only mildly developmentally delayed. One patient presented with the distinctive facial appearance, large fontanels, and joint abnormalities. The other had none of the typical congenital abnormalities. However, the patient was found to have a congenital heart defect and hypoplastic left heart syndrome, which to our knowledge has not been reported previously in the trisomy 9 syndrome. When these two patients are added to the published patients with this syndrome, there appears to be a range of manifestations, especially with respect to mental status, which has not fully been recognized.

In vitro effects of lecithin:cholesterol acyltransferase on apolipoprotein distribution in familial lecithin:cholesterol acyltransferase deficiency.

Action of LCAT on the plasma of patients afflicted with familial LCAT deficiency shifts the distribution of C apolipoproteins from lipoproteins of d less than 1.019 g/ml to lipoproteins of d greater than 1.109 g/ml, and causes an opposite shift in the distribution of apolipoprotein E. The altered distribution of apolipoprotein E appears to depend primarily on enzyme-related effects on HDL. Loss of apolipoprotein E from HDL occurs as cholesteryl esters are formed and transfer to other lipoproteins; disc-shaped HDL, rich in apolipoprotein E, are converted into spherical particles; and the population of HDL as a whole is converted first into particles the size of HDL2 and HDL3 and then into intermediate-sized particles. Transfer of apolipoprotein E to artificially prepared triglyceride-rich particles occurs at a nearly linear rate that is slow than the rates of formation and transfer of cholesteryl esters or the rate of formation of "HDL2" and "HDL3." Transfer of apolipoprotein E is faster, however, when the patients' disc-shaped HDL are incubated with triglyceride-rich particles in the presence of normal plasma lipoproteins of d greater than 1.063 g/ml. Since the disc-shaped HDL, rich in apolipoprotein E, resemble particles reported to be released from perfused rat livers, they may be nascent lipoproteins of hepatic origin. If so, it appears that action of LCAT on these lipoproteins may be one of the factors that regulates the content of apolipoprotein E in VLDL.

The "differential diagnosis" for multiple diseases: comparison with the binary-truth state experiment in two empirical studies.

RATIONALE AND OBJECTIVES: In practice readers must often choose between multiple diagnoses. For assessing reader accuracy in these settings. Obuchowski et al have proposed the "differential diagnosis" method, which derives all pairwise estimates of accuracy for the various diagnoses, along with summary measures of accuracy. The current study assessed the correspondence between the differential diagnosis method and conventional binary-truth state experiments. MATERIALS AND METHODS: Two empirical studies were conducted at two institutions with different readers and diagnostic tests. Readers used the differential diagnosis format to interpret a set of cases. In subsequent readings they interpreted the cases in binary-truth state experiments. Spearman rank correlation coefficients and the percentages of agreement in scores were computed, and the areas under the receiver operating characteristic curves were estimated and compared. RESULTS: The between-format Spearman rank correlation coefficients were 0.697-0.718 and 0.750-0.780 for the two studies; the between-reader correlations were 0.417 and 0.792, respectively. The percentages of agreement between formats for the two studies were 50.0%-51.7% and 72.9%-78.8%; the percentages of agreement between readers were 45.0% and 80%, respectively. In the first study there were several significant differences in the areas under receiver operating characteristic curves; in the second study these differences were small. CONCLUSION: The differences observed between the two formats can be attributed to within-reader variability and inherent differences in the questions posed to readers in the multiple-diagnoses versus binary-truth state reading sessions. The differential diagnosis format is useful for estimating accuracy when there are multiple possible diagnoses.

A prospective comparison of high-resolution planar, pinhole, and triple-detector SPECT for the detection of renal cortical defects.

To compare the detection rate of renal cortical defects with Tc-99m dimercaptosuccinic acid (DMSA) using triple-detector SPECT, pinhole, and planar cortical scintigraphy, the authors prospectively studied 80 kidneys in 40 patients (26 males, 14 females) who ranged in age from 3 months to 26 years (mean: 7.5 years). They found single or multiple definite defects in 30 kidneys using SPECT, 23 using pinhole imaging, and 17 using planar imaging (McNemar's test, two-tailed, P < 0.001 and P = 0.03, respectively). SPECT was significantly better than pinhole imaging at demonstrating definite defects (P = 0.008). This study indicates that SPECT, and to a lesser extent pinhole, are superior to planar imaging for conclusively demonstrating renal cortical defects.

Ulnar artery occlusion in mountain bikers.

We report two cases of the hypothenar hammer syndrome, diagnosed with digital angiography, which occurred in mountain bikers. To our knowledge, the association between mountain bike enthusiasts and ulnar artery occlusion has not been reported in the literature.

Plasma lipoproteins in familial lecithin: cholesterol acyltransferase deficiency: effects of dietary manipulation.

To study the metabolism of the abnormal plasma lipoproteins in familial lecithin:cholesterol acyltransferase deficiency we performed five dietary experiments designed to perturb their distribution and composition. Four patients with the disease were given successive diets that differed in triglyceride, carbohydrate, or cholestrol content, and after each dietary period the lipoproteins were analyzed by combinations of preparative and analytical ultracentrifugation, gel filtration, chromatography, and disc gel electrophorsis. Lowering the intake of long chain, dietary triglyceride descreased the concentrations of the large very low density lipoproteins, the large and intermediate low density lipoproteins, and the small high density lipoproteins by as much ad 79 %, but either increased or did not change the concentrations of the small very low and low density lipoproteins. Re-adding long chain triglycerdine to the diet generally reversed these effects, but increasing the dietary cholesterol without lowering the dietary triglyceride only decreased the concentration of plasma cholesteryl ester. We conclude that the concentrations of the large very low and low sensity lipoproteins, the intermediate-sized low density lipoproteins, and the small high density lipoproteins are related to the absorption and subsequent transport of long chain dietary fatty acids. Since these lipoproteins are rich in unesterified cholesterol and lecithin, two polar lipids that form a substantial part of the surfaces of chylomicrons, components of chylomicron surfaces may accumulate in the patient's plasma following enzymic removal of chylomicron triglyceride and contribute to several of the abnormal lipoproteins.

Fluoroscopic-guided lumbar puncture: fluoroscopic time and implications of body mass index--a baseline study.

BACKGROUND AND PURPOSE: Fluoroscopic-guided lumbar puncture is an effective alternative to bedside lumbar puncture in challenging patients. However, no published guidelines are available for an acceptable range of fluoroscopic time for this procedure. The purpose of this study was to set department benchmark fluoroscopic times for lumbar puncture, accounting for body mass index in our patient population. MATERIALS AND METHODS: We identified and reviewed all patients who underwent fluoroscopic-guided lumbar puncture at 4 hospitals during a 2-year period (July 2011 to June 2013). Data collection included patient information (demographics, body mass index, history of prior lumbar surgery and/or lumbar hardware, scoliosis); procedure details (fluoroscopic time, level of access, approach, needle gauge and length); level of operator experience; and hospital site. A generalized linear model was used to test whether body mass index influenced fluoroscopic time while controlling other factors. RESULTS: Five hundred eighty-four patients (mean age, 47.8 ± 16.2 years; range, 16-92 years; 33% male) had successful fluoroscopic-guided lumbar puncture s. Mean body mass index and fluoroscopic time were higher in female patients (34.4 ± 9.9 kg/m(2) and 1.07 minutes; 95% CI, 0.95-1.20) than in male patients (29.2 ± 7.3 kg/m(2) and 0.91 minutes; 95% CI, 0.79-1.03). Body mass index (P = .001), hospital site (P < .001), and level of experience (P = .03) were factors significantly affecting fluoroscopic time on multivariate analysis. Benchmark fluoroscopic times in minutes were the following: 0.48 (95% CI, 0.40-0.56) for normal, 0.61 for overweight (95% CI, 0.52-0.71), 0.63(95% CI, 0.58-0.73) for obese, and 0.86 (95% CI, 0.74-1.01) in extremely obese body mass index categories. CONCLUSIONS: In patients undergoing fluoroscopic-guided lumbar punctures, fluoroscopy time increased with body mass index We established benchmark fluoroscopic-guided lumbar puncture time ranges as related to body mass index in our patient population.