A survey of the radiation safety practices of veterinary practitioners during portable equine radiography in Ireland.

Veterinary practitioners and other personnel involved in the examination are exposed to ionizing radiation while performing portable radiographs on horses. An online survey was distributed to all Veterinary Council of Ireland-registered practices where the self-reported practice profile is at least 20% equine work. The survey contained questions relating to radiation safety training, protocols, personal dosimetry and lead protection usage, repeat exposures, sedation, and personnel roles during the examination. The aim of the survey was to document the current radiation safety practices of equine veterinary practitioners during portable radiography. The results showed that although adherence to guidance set out by the Environmental Protection Agency (EPA) is reasonably good, compliance rates can be improved. Personal dosemeter usage and repeat rate reduction could particularly benefit from further improvement. This is of the utmost importance in ensuring that occupational radiation exposure to veterinary practitioners is kept to an absolute minimum during their daily practice.

Diagnostic chest X-rays and breast cancer risk among women with a hereditary predisposition to breast cancer unexplained by a BRCA1 or BRCA2 mutation.

BACKGROUND: Diagnostic ionizing radiation is a risk factor for breast cancer (BC). BC risk increases with increased dose to the chest and decreases with increased age at exposure, with possible effect modification related to familial or genetic predisposition. While chest X-rays increase the BC risk of BRCA1/2 mutation carriers compared to non-carriers, little is known for women with a hereditary predisposition to BC but who tested negative for a BRCA1 or BRCA2 (BRCA1/2) mutation. METHODS: We evaluated the effect of chest X-rays from diagnostic medical procedures in a dataset composed of 1552 BC cases identified through French family cancer clinics and 1363 unrelated controls. Participants reported their history of X-ray exposures in a detailed questionnaire and were tested for 113 DNA repair genes. Logistic regression and multinomial logistic regression models were used to assess the association with BC. RESULTS: Chest X-ray exposure doubled BC risk. A 3% increased BC risk per additional exposure was observed. Being 20 years old or younger at first exposure or being exposed before first full-term pregnancy did not seem to modify this risk. Birth after 1960 or carrying a rare likely deleterious coding variant in a DNA repair gene other than BRCA1/2 modified the effect of chest X-ray exposure. CONCLUSION: Ever/never chest X-ray exposure increases BC risk 2-fold regardless of age at first exposure and, by up to 5-fold when carrying 3 or more rare variants in a DNA repair gene. Further studies are needed to evaluate other DNA repair genes or variants to identify those which could modify radiation sensitivity. Identification of subpopulations that are more or less susceptible to ionizing radiation is important and potentially clinically relevant.

A review of the types of childhood cancer associated with a medical X-ray examination of the pregnant mother.

PURPOSE: For 65 years the interpretation of the statistical association between the risk of cancer in a child and a prior diagnostic X-ray examination of the abdomen of the pregnant mother has been debated. The objections to a direct cause-and-effect explanation of the association vary in their strength, but one of the most notable grounds for controversy is the finding from the first and largest case-control study reporting the association, the Oxford Survey of Childhood Cancers (OSCC), of an almost uniformly raised relative risk (RR) for nearly all of the types of cancer that are most frequent in children. Here we compare the antenatal X-ray associations found in the OSCC for different types of childhood cancer with the results of all other case-control and case-cohort studies appropriately combined in meta-analyses, and we also review the findings of the few cohort studies that have been conducted. CONCLUSIONS: From the case-control/case-cohort studies other than the OSCC there are consistent and clear elevations of risk for all types of childhood cancer combined, all leukemia, and all cancers except leukemia combined. This compatibility of the findings of the OSCC with those of the combined other studies is less clear, or effectively absent, when some categories containing smaller numbers of incident cases/deaths are considered, but lack of precision of risk estimates due to sparse data presents inferential challenges, although there is a consistent absence of an association for bone tumors. Further, more recent studies almost certainly address lower intrauterine doses, with an anticipated decrease in estimated risks, which could be misleading when comparisons involve a limited number of studies that are mainly from later years, and a similar problem arises when having to employ all types of antenatal X-ray exposures for a study because data for abdominal exposures are absent. The problem of low statistical power is greater for cohort studies, and this, together with other shortcomings identified in the studies, limits the interpretational value of results. The findings of non-medical intrauterine exposure studies are constrained by sparse data and make a limited contribution to an understanding of the association. Certain aspects of the various studies require a need for caution in interpretation, but overall, the appropriate combination of all case-control/case-cohort studies other than the OSCC lends support to the inference that low-level exposure to radiation in utero proportionally increases the risk of the typical cancers of childhood to around the same level.

Fluoroscopy X-Ray Organ-Specific Dosimetry System (FLUXOR) for Estimation of Organ Doses and Their Uncertainties in the Canadian Fluoroscopy Cohort Study.

As part of ongoing efforts to assess lifespan disease mortality and incidence in 63,715 patients from the Canadian Fluoroscopy Cohort Study (CFCS) who were treated for tuberculosis between 1930 and 1969, we developed a new FLUoroscopy X-ray ORgan-specific dosimetry system (FLUXOR) to estimate radiation doses to various organs and tissues. Approximately 45% of patients received medical procedures accompanied by fluoroscopy, including artificial pneumothorax (air in pleural cavity to collapse of lungs), pneumoperitoneum (air in peritoneal cavity), aspiration of fluid from pleural cavity and gastrointestinal series. In addition, patients received chest radiographs for purposes of diagnosis and monitoring of disease status. FLUXOR utilizes age-, sex- and body size-dependent dose coefficients for fluoroscopy and radiography exams, estimated using radiation transport simulations in up-to-date computational hybrid anthropomorphic phantoms. The phantoms include an updated heart model, and were adjusted to match the estimated mean height and body mass of tuberculosis patients in Canada during the relevant time period. Patient-specific data (machine settings, exposure duration, patient orientation) used during individual fluoroscopy or radiography exams were not recorded. Doses to patients were based on parameter values inferred from interviews with 91 physicians practicing at the time, historical literature, and estimated number of procedures from patient records. FLUXOR uses probability distributions to represent the uncertainty in the unknown true, average value of each dosimetry parameter. Uncertainties were shared across all patients within specific subgroups of the cohort, defined by age at treatment, sex, type of procedure, time period of exams and region (Nova Scotia or other provinces). Monte Carlo techniques were used to propagate uncertainties, by sampling alternative average values for each parameter. Alternative average doses per exam were estimated for patients in each subgroup, with the total average dose per individual determined by the number of exams received. This process was repeated to produce alternative cohort vectors of average organ doses per patient. This article presents estimates of doses to lungs, female breast, active bone marrow and heart wall. Means and 95% confidence intervals (CI) of average organ doses across all 63,715 patients were 320 (160, 560) mGy to lungs, 250 (120, 450) mGy to female breast, 190 (100, 340) mGy to heart wall and 92 (47, 160) mGy to active bone marrow. Approximately 60% of all patients had average doses to the four studied organs of less than 10 mGy, 10% received between 10 and 100 mGy, 25% between 100 and 1,000 mGy, and 5% above 1,000 mGy. Pneumothorax was the medical procedure that accounted for the largest contribution to cohort average doses. The major contributors to uncertainty in estimated doses per procedure for the four organs of interest are the uncertainties in exposure duration, tube voltage, tube output, and patient orientation relative to the X-ray tube, with the uncertainty in exposure duration being most often the dominant source. Uncertainty in patient orientation was important for doses to female breast, and, to a lesser degree, for doses to heart wall. The uncertainty in number of exams was an important contributor to uncertainty for ∼30% of patients. The estimated organ doses and their uncertainties will be used for analyses of incidence and mortality of cancer and non-cancer diseases. The CFCS cohort is an important addition to existing radio-epidemiological cohorts, given the moderate-to-high doses received fractionated over several years, the type of irradiation (external irradiation only), radiation type (X rays only), a balanced combination of both genders and inclusion of people of all ages.

What information did pregnant women want related to risks and benefits attending X-ray examinations?

BACKGROUND: In connection with X-ray examinations of pregnant patients, good communication of benefit and risk is important to provide adequate patient care. Pregnant women often become concerned about the foetus and are unsure of the risk of malformations and the development of cancer. Health professionals who are involved in imaging pregnant women require specif knowledge about risks and benefits so they can convey information without creating unnecessary fear. PURPOSE: This study identifies the information needs of pregnant women in connection with X-ray examinations and how they prefer to have the information communicated. METHOD: A qualitative study using semi-structured interviews of seven pregnant women aged 28-36 in weeks 16-33 of their pregnancy. The interviews were analysed using interpretive phenomenological analysis. RESULTS: The participants had expectations regarding the information provided about X-ray examinations during pregnancy. They needed concrete information on radiation doses, risks and any effects on the foetus. The risk was thought to be low, but several of the participants would still have been concerned when undergoing an X-ray examination. CONCLUSION: To provide adequate care of pregnant women in connection with X-ray examinations, healthcare professionals must have knowledge of pregnancy and radiation and have expertise in risk communication. This will prevent unnecessary concern in the pregnant woman, ensure that justified necessary examinations are carried out, and avoid adverse decisions such as termination of pregnancy based on erroneous grounds.

Low Radiation X-rays: Benefiting People Globally by Reducing Cancer Risks.

Modern medical imaging facilitates the diagnosis and treatment of human diseases. However, few people are aware of the cons of radiation exposure from medical imaging. Emerging evidence reveals that cumulative doses of radiation exposure will increase the morbidity and mortality of pertaining cancer. As a special young population, patients with adolescent idiopathic scoliosis (AIS) suffer more radiation harms from repeated diagnostic imaging, most of which can be avoided in clinical practice. Accumulating evidence highlights reduced cancer risks of radiation exposure for AIS patients with low/zero radiation imaging modalities proposed, amongst which easy conversion from anterior-posterior (AP) to posterior-anterior (PA) projection for whole-spine radiographs should be stressed. It can greatly reduce radiation doses without compromising the quality of diagnostic imaging. Tight collimation combined with PA projection can further reduce radiation harms, and need to be spread to benefit people globally.

Patient safety incidents in radiology: frequency and distribution of incident types.

BACKGROUND: Patient safety incidents may be a valuable source of information to learn from and to prevent future errors. PURPOSE: To determine the distribution of patient safety incident types in radiology according to the International Classification for Patient Safety (ICPS), and to comprehensively review those incidents that were either harmful or serious in terms of risk of patient harm and reoccurrence. MATERIAL AND METHODS: The most recent five-year database (2014-2019) of a radiology incident reporting system was evaluated. RESULTS: A total of 480 patient safety incidents were included. Top three ICPS incident types were clinical administration (119/480, 24.8%), resources/organizational management (112/480, 23.3%), and clinical process/procedure (91/480, 19.0%). Harm severities were none in 457 (95.2%) cases, mild in 14 (2.9%), moderate in 4 (0.8%), severe in 3 (0.6%), and unknown in one case. Subsequent Prevention Recovery Information System for Monitoring and Analysis (PRISMA) reviews were performed in 4 (0.8%) cases. The three patient safety incidents that caused severe harm (of which one underwent PRISMA review) involved resources/organizational management (n = 1), clinical process/procedure (n = 1), and medication/IV fluids (n = 1). Three other cases (with no harm in two cases and moderate harm in one case) that underwent PRISMA review involved resources/organizational management (n = 2) and medical device/equipment/property (n = 1). CONCLUSION: Radiology-related patient safety incidents predominantly occur in three ICPS domains (clinical administration, resources/organizational management, and clinical process/procedure). Harmful/serious incidents are relatively rare. The standardly and transparently reported findings from this study may be used for healthcare quality improvement, benchmarking purposes, and as a primer for future studies.

Adherence to guidelines aimed at preventing post-contrast acute kidney injury (PC-AKI) in radiology practices: a survey study.

BACKGROUND: New insights into post-contrast acute kidney injury (PC-AKI) have recently led to the guidelines on the prevention of PC-AKI being updated. However, little is known about the barriers and facilitators involved in guideline adherence by radiology practices. PURPOSE: To evaluate barriers and facilitators to the adherence of PC-AKI guidelines. MATERIAL AND METHODS: Radiologists visiting the European Society of Urogenital Radiology (ESUR) 2018 meeting, as well as ESUR members were contacted to fill in an electronic questionnaire on the implementation of PC-AKI guidelines applying to their local radiology practices. RESULTS: Of the 145 responding radiologists representing radiology practices, 127 (88%) confirmed having a PC-AKI protocol in place in their radiology practice, of which 61 (48%) used a protocol as specified in a (inter)national guideline. The majority of radiology practices of the respondents used the ESUR guideline (40%). Barriers for not using PC-AKI prevention guidelines were related to a lack of outcome expectancy. Barriers for not using the protocol as specified were related to a lack of agreement with specific recommendations, lack of motivation, guideline-specific factors, and environmental factors. Self-reported facilitators consisted of guideline-specific factors. CONCLUSION: Guidelines for the prevention of PC-AKI seem to be widely implemented among radiology practices, and regularly locally modified because of barriers involved in agreement and behavior. Knowledge of the barriers and facilitators of guideline adherence will aid future efforts aimed at bridging the gap between awareness and implementation of evidence-based guidelines in radiology practices.

The radioprotective effect of melatonin against radiation-induced DNA double-strand breaks in radiology.

OBJECTIVE: The objective of this study is to observe the effect of 100-mg melatonin in reducing the levels of double-strand breaks (DSB) induced by 10 mGy and 100 mGy X-ray in peripheral lymphocyte applying H2AX immunofluorescence microscopy and comparing the different efficacies of melatonin ingestion 1 and 2 h before irradiation. MATERIALS AND METHODS: Informed consent was obtained from five healthy males, nonathlete, and nonsmoking human volunteers aged between 25 and 35 years. Each volunteer was given a single oral dose of 100 mg melatonin at 9 a.m. Blood samples were collected in vacutainer tubes (without any preservative to separate the serum, and with heparin as an anticoagulant for separating leukocytes for in vitro exposure to gamma radiation) 5-10 min before then 1 and 2 h after melatonin ingestion. Afterward, each sample was subdivided into nonirradiated and irradiated groups (10 mGy and 100 mGy). After irradiation, lymphocytes of samples were separated. The isolated lymphocytes in each group were permeabilized for DSB assessment and stained against the phosphorylated histone variant γH2AX. RESULTS: Melatonin ingestion 1 and 2 h before irradiation caused a significant reduction in γH2AX foci. Results further indicate that the change in ingestion of melatonin from 1 to 2 h before exposure had no significant effect. In addition, melatonin administration showed no side effects. CONCLUSION: The present study showed that melatonin will prove effective in radioprotection against ionizing radiation (IR)-induced DNA damage in human lymphocytes. Our results suggest ingestion of 100-mg melatonin by patients before exposure to IR in radiology.

Comparison of air dose and operator exposure from portable X-ray units.

This study was aimed at investigating and comparing exposure dose of workers and the surrounding workers. In addition, worker's exposure was also measure about lens and finger. Four intraoral portable X-ray units were evaluated. The stray radiations were measured using Pitman 37D and ionization chamber (Pitman). MyDosemini (ALOKA) was used for measurement of the finger exposure dose. Without the shield became high in anterior 0.5 m. Comparing the air dose for the four models used in this study showed a high tendency for the two NOMAD models. And using the shields, the images could be taken 4.6 times of the baseline at a maximum and 3.6 times on average. The finger radiation exposure dose was low with both of the NOMAD models, with no significant difference found. By setting the baseline value without a shield, finger radiation exposure when using a shield was lower than the detection limit for the D3000, and was reduced by approximately 94-96% for other three models. All models can photograph around 100 bodies, so it is considered that it is not necessary to switch out the operator considering the operation limit. But even if it does not reach the operation limit, the stochastic effects of radiation exposure can be increased as well as the deterministic effects of the operation limit. The operator and the surrounding workers seek to protect themselves. It is important to perform exposure management that takes into account the stochastic effects to the operator and the surrounding workers.

Lead-free transparent shields for diagnostic X-rays: Monte Carlo simulation and measurements.

In recent years, the preference for using lead-free radiation protection shields has increased because of concerns regarding lead poisoning and leakage. In medical and research laboratories, glass shields are preferred because of their transparency. In this study, various glass shields were examined and compared based on the international standards. One commercially available lead-based shield, four recently studied shields, and three new lead-free shields were considered, and their shielding factors were calculated. We presented three glasses based on borate, phosphate, and silicate compounds, which were named Ir1, Ir2, and Ir3, respectively. Based on the International Electrotechnical Commission standard (IEC 61331), the air-kerma ratios (attenuation ratios) and lead equivalent values were derived using Monte Carlo N-Particle eXtended (MCNPX) calculations, and mass attenuation coefficients and effective atomic numbers (Zeff) of all the shields were obtained from XCOM database, in the diagnostic X-ray energy range of 40-120 keV. In addition, some measurements were performed for the reference (lead-based) glass to validate the simulations. The above-mentioned factors for silicate-bismuth-based (Ir3) and borosilicate-barium-based (Tu) glasses were found to be higher than the others and comparable to those of commercially available lead-based glass. In conclusion, Ir3 and Tu glasses were found to be the preferred lead-free transparent shields in the diagnostic X-ray energy range.

The downfall of the linear non-threshold model. / El ocaso del modelo lineal sin umbral.

The linear non-threshold model (LNTM) is a theoretical dose-response function as a result of extrapolating the late effects of high-dose exposure to ionizing radiation to the low-dose range, but there is great uncertainty about its validity. The acceptance of LNTM as the dominant probabilistic model have survived to the present day and it is actually the cornerstone of current radiation protection policies. In the last decades, advances in molecular and evolutive biology, cancer immunology, and many epidemiological and animal studies have cast serious doubts about the reliability of the NLTM, as well as suggesting alternative models, like the hormetic theory. Considering the given evidences, a discussion between the involved scientific societies and the regulatory commissions is promtly required in order to to reach a redefiniton of theradiation protection basis, as it would be specially crucial in the medical field.

Reduction of operator exposure by rectangular collimation in portable intraoral radiography.

Portable intraoral X-ray units are frequently used for home-visit dental treatment and personal dental identification. Therefore, the reduction of operator exposure is crucial. Rectangular collimation is effective at reducing patient exposure and operator exposure; however, its effects are not known. We investigated the reduction of operator exposure through rectangular collimation by measuring the backscattered dose in relation to the operator exposure dose. Using a portable intraoral X-ray unit, a head phantom for CT dose measurement as the object, a dosimeter, and stainless-steel rectangular collimator, a 1-cm ambient dose equivalent was measured in intervals of 15° in horizontal and vertical planes with the radii of 50 and 100 cm. The backscattered dose decreased to approximately one-third when a rectangular collimator was attached to the cone tip. This may have been due to the reduction of the volume of scattered X-rays generated in the phantom by rectangular collimation. We clarified that rectangular collimation is effective at reducing the operator exposure and is useful for protecting the operators of portable intraoral X-ray units during home-visit dental treatment and personal dental identification.

Potentially Harmful Ionizing Radiation Exposure from Diagnostic Tests and Medical Procedures in Patients with Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Patients with aneurysmal subarachnoid hemorrhage (aSAH) may have significant potentially harmful ionizing radiation exposure (PHIRE) from diagnostic tests and medical procedures (DTMP) during their initial hospitalization. METHODS: In this single-center, retrospective, observational study, we evaluated the incidence of PHIRE using all patients with radiographically proven aSAH who survived hospitalization over a 6-year period. Patient data were then used to fit a full logistic regression model, a reduced-variable logistic regression model with least absolute shrinkage and selection operator penalty, and a nonparametric tree-based model. Testing data were then used to calculate each predictive model's accuracy. RESULTS: Of 192 patients included in this study, 69 (35.9%) met criteria for PHIRE. Patients with PHIRE were more likely to have a poor Hunt-Hess Score (40.6% vs. 12.2%, P < 0.0001), a poor modified Fischer Grading Scale score (30.4% vs. 16.3%, P = 0.03), ventriculostomy (91.3% vs. 47.2%, P < 0.0001), vasospasm (81.2% vs. 34.1%, P < 0.0001), and ventriculoperitoneal shunt (31.9% vs. 10.6%, P < 0.001). Parametric PHIRE prediction modeling with a full logistic regression model and reduced-logistic regression modeling with least absolute shrinkage and selection operator penalty demonstrated PHIRE prediction accuracy of 67% and 78% accuracy, respectively. Nonparametric tree-based PHIRE modeling demonstrated a prediction accuracy of 58%. CONCLUSIONS: On the basis of our data, PHIRE occurs in approximately 35% of aSAH patients. The reduced-variable logistic regression model had the greatest predictive accuracy for PHIRE. Future studies should validate our findings and predictive models and, if our conclusions hold, further clarification of the risks of PHIRE and methods to reduce PHIRE should be investigated.

Do Children With Spinal Deformity Who Have Metal Implants and Frequent Exposure to X-Rays Increase Their Risk of Cancer?

STUDY DESIGN: Spinal surgery cohort. OBJECTIVE: The authors assess the risk of cancer in children who have undergone frequent radiographs and have metal implants for the treatment of spinal deformity. SUMMARY OF BACKGROUND DATA: Concerns have been raised regarding the cancer risk to children exposed to repeated radiological examinations as part of routine surveillance to monitor progression of spinal deformity. Additionally, there are reports of increased cancer risk in adults having joint replacement with metal implants causing raised metal ion levels in the blood. METHODS: A large number of consecutive children undergoing instrumented spinal surgery since 1979 were examined for their development of malignancy. High quality data on all invasive cancers from the South Australian Cancer Registry and deaths were linked to the spinal surgery cohort with the calculation of standardized incidence ratios (SIRs) using the Quinquinquennium method. RESULTS: The study cohort was formed by 865 children. The average follow-up time from date of surgery to either death or censoring date was 18 years with a maximum of 36 years. A total of 15,921 person years were examined. There was no increased rate of cancer in these patients. For the total cohort, the SIR was 1.00 (95% confidence interval [CI] 0.50-1.79). For females the SIR was 0.83 (95% CI 0.33-1.70) and for males the SIR was 1.33 (95% CI 0.36-3.40). The male SIR reflected an expected cancer incidence of three cases, when four cases were observed, and was not statistically significant. CONCLUSION: This study has found that radiation exposure and possible exposure to circulating metal ions as a result of routine instrumented spine surgery in children since 1979 is not associated with an increased risk of cancer in up to 36 years of follow up. LEVEL OF EVIDENCE: 2.

Exposure to Medical Radiation during Fetal Life, Childhood and Adolescence and Risk of Brain Tumor in Young Age: Results from The MOBI-Kids Case-Control Study.

BACKGROUND: We explored the association between ionizing radiation (IR) from pre-natal and post-natal radio-diagnostic procedures and brain cancer risk within the MOBI-kids study. METHODS: MOBI-kids is an international (Australia, Austria, Canada, France, Germany, Greece, India, Israel, Italy, Japan, Korea, New Zealand, Spain, The Netherlands) case-control study including 899 brain tumor (645 neuroepithelial) cases aged 10-24 years and 1,910 sex-, age-, country-matched controls. Medical radiological history was collected through personal interview. We estimated brain IR dose for each procedure, building a look-up table by age and time period. Lifetime cumulative doses were calculated using 2 and 5 years lags from the diagnostic date. Risk was estimated using conditional logistic regression. Neurological, psychological and genetic conditions were evaluated as potential confounders. The main analyses focused on neuroepithelial tumors. RESULTS: Overall, doses were very low, with a skewed distribution (median 0.02 mGy, maximum 217 mGy). ORs for post-natal exposure were generally below 1. ORs were increased in the highest dose categories both for post and pre-natal exposures: 1.63 (95% CI 0.44-6.00) and 1.55 (0.57-4.23), respectively, based on very small numbers of cases. The change in risk estimates after adjustment for medical conditions was modest. CONCLUSIONS: There was little evidence for an association between IR from radio-diagnostic procedures and brain tumor risk in children and adolescents. Though doses were very low, our results suggest a higher risk for pre-natal and early life exposure, in line with current evidence.

Evaluating the role of surface topography in the surveillance of scoliosis.

STUDY DESIGN: Literature review. OBJECTIVE: To review the history, modern uses, limitations, and future direction of surface topography (ST) in surveillance of scoliosis. Spinal deformities, including scoliosis, can be characterized using measurements such as the Cobb angle, lateral curvature, and vertebral rotation. The gold standard for diagnosis and surveillance of such deformities utilizes radiographic images. To minimize repeated radiation exposure, many systems have been developed utilizing ST. ST measures local deviations of a surface from a flat plane. Applying this concept to spinal deformities, ST can non-radiographically study the 3-dimensional shape of the back. One ST system, rasterstereography, projects parallel white light lines onto a patient's back and analyzes line distortion with a camera. While radiography has long been considered the primary diagnostic tool for scoliosis, rasterstereography may possess alternative or complementary benefits in monitoring scoliosis and other diseases. METHODS: A comprehensive literature review was performed on the history, development, and validity of ST. The advantages and limitations of this technique were compared to those of radiography. RESULTS: While the initial goal of ST, designing a system to accurately reproduce the Cobb angle, was not successful, research efforts over the last 40 years have attempted to improve this correlation. ST technologies, including rasterstereography and the Formetric ST System, currently play important roles in scoliosis surveillance, research, and minimizing radiation exposure in longitudinal care of patients. Such technologies are also useful as an adjunct to X-rays for monitoring disease progression, especially in Parkinson's disease. CONCLUSION: Despite its limitations, ST has proven useful across multiple fields of medicine. It is a safe and cost-effective tool for long-term surveillance of scoliosis and early detection of progressive disease. With technological improvements, the Formetric System will become a critical alternative in dynamic spinal motion and gait analysis. LEVEL OF EVIDENCE: N/A.

Multinational data on cumulative radiation exposure of patients from recurrent radiological procedures: call for action.

OBJECTIVES: To have a global picture of the recurrent use of CT imaging to a level where cumulative effective dose (CED) to individual patients may be exceeding 100 mSv at which organ doses typically are in a range at which radiation effects are of concern METHODS: The IAEA convened a meeting in 2019 with participants from 26 countries, representatives of various organizations, and experts in radiology, medical physics, radiation biology, and epidemiology. Participants were asked to collect data prior to the meeting on cumulative radiation doses to assess the magnitude of patients above a defined level of CED. RESULTS: It was observed that the number of patients with CED ≥ 100 mSv is much larger than previously known or anticipated. Studies were presented in the meeting with data from about 3.2 million patients who underwent imaging procedures over periods of between 1 and 5 years in different hospitals. It is probable that an additional 0.9 million patients reach the CED ≥ 100 mSv every year globally. CONCLUSIONS: There is a need for urgent actions by all stakeholders to address the issue of high cumulative radiation doses to patients. The actions include development of appropriateness criteria/referral guidelines by professional societies for patients who require recurrent imaging studies, development of CT machines with lower radiation dose than today by manufacturers, and development of policies by risk management organizations to enhance patient radiation safety. Alert values for cumulative radiation exposures of patients should be set up and introduced in dose monitoring systems. KEY POINTS: • Recurrent radiological imaging procedures leading to high radiation dose to patients are more common than ever before. • Tracking of radiation exposure of individual patients provides useful information on cumulative radiation dose. • There is a need for urgent actions by all stakeholders to address the issue of high cumulative radiation doses to patients.