Ionising Radiation Regulations Research Articles

Occupational skin dose from radionuclide contamination: one country's approach at standardising skin dose estimates using Varskin.

The manipulation of unsealed radiopharmaceuticals by healthcare workers can cause accidental personal contamination leading to occupational radiation skin dose. The UK Ionising Radiations Regulations 2017 require that potential skin doses arising from reasonably foreseeable accident scenarios are included in risk assessments. Workers must be designated as classified if these dose estimates exceed 150 mSv equivalent dose averaged over 1 cm2. Updates from the UK Health and Safety Executive recently prompted many in the UK to review the classification of workers in Nuclear Medicine. Skin dose from contamination cannot be measured, it must be estimated. Varskin+ is a code that is widely recommended for estimating skin dose. The subjective choices made by users when defining modelled scenarios in Varskin+ lead to significant variation in the calculated skin doses. At the time of writing there is no definitive calculation method and all calculations rely on theoretical models. NHS Health Boards in Scotland have adopted a standardised framework for performing skin dose estimates for risk assessments. The parametric sensitivity of Varskin+ inputs were examined and the available evidence was reviewed. Generic, reasonably forseeable, worst-case accident scenarios were decided upon for: direct skin contamination, glove contamination and needlestick injury. Standardised inputs and assumptions for each scenario were compiled in a protocol that has been adopted by the Scottish Health Boards. The protocol allows for differences in practice between departments, but standardises most inputs. While significant uncertainty remains in the estimated skin doses, this approach reduces variation and enables the comparison of estimated skin doses between departments. The framework facilitates continuous improvement as more evidence is gathered to refine the standardised assumptions. Task by task skin dose estimates were made for workers in Nuclear Medicine in Scotland and many workers were designated classified as a result.

Increasing the public awareness of justification

One of the requirements of the UK Ionising Radiation (Medical Exposure) Regulations 2017 is that all medical exposures must be justified before the exposure can proceed. One of the main elements of justification is a determination that the medical benefits from the exposure will exceed the associated radiation detriment. The field of medical exposure to ionising radiation is in the rare position of having this explicit legal requirement for net benefit. In this article it is argued that, although separate information on benefit and detriment is also required for implied or explicit informed consent prior to exposure, justification comes first, is simple to explain, and is easily related to the commonly understood basis of medical ethics. It seems reasonable, therefore, to make patients and the public more aware of the protection that UK law already provides for them. A proposal for a single-sentence general statement on justification is made.

Improving radiation protection amongst the UK vascular surgery workforce

The use of ionising radiation in the UK is regulated nationally through legislation. The legal requirements for employers for the protection of radiation exposed workers are detailed in Ionising Radiation Regulations 2017 (IRR17),1 Ionising Radiation (Medical Exposure) Regulations 2017 (IRMER17)2 and Ionising Radiation (Medical Exposure) (Amendment) Regulations 2018,3 with the ultimate responsibility for their enforcement sitting with the Health and Safety Executive (HSE), Britain’s national regulator for workplace health and safety.

500 CT imaging requests in Major Trauma Patients

Abstract Introduction There is a correlation between adequate CT Trauma orders and accuracy of radiological reporting. In this audit, the aim is to improve accuracy of reporting by following the Royal College of Radiologists (RCR) indications for polytrauma CT imaging in the document ‘Standards of practice and guidance for trauma radiology in severely injured patients, 2nd edition’. Standard 7 in this guidance states that a CT request in the trauma setting should comply with the Ionising Radiation (Medical Exposure) Regulations justification regulations in the same way as any other request for imaging involving ionising radiation. Method Clinical information in CT orders of 57 major trauma patients in the East Midlands Major Trauma Centre were reviewed against ‘Standards of practice and guidance for trauma radiology in severely injured patients, 2nd edition’. The request should have two essential pieces of information: mechanism of injury and suspected injuries. In these 57 patient, 96% had appropriate requests. Since the target is 100%, an email was sent out and a teaching session was carried out to improve practice. A second cycle including 80 patients in the same centre was carried out. Results Before intervention, 96% of the CT in major trauma patients were compliant with guidelines. After intervention, this improved to 100%. Conclusion Compliance with RCR criteria improved after intervention, this surely helped avoid unnecessary radiation exposure and enhanced radiological reporting in major trauma patient scans.

Machine learning to predict environmental dose rates from a radionuclide therapy service — a proof of concept study

The Ionising Radiation Regulations 2017 requires prior risk assessment calculations and regular environmental monitoring of radiation doses. However, the accuracy of prior risk assessments is limited by assumptions and monitoring only provides retrospective evaluation. This is particularly challenging in nuclear medicine for areas surrounding radionuclide therapy patient bathroom wastewater pipework. Machine learning (ML) is a technique that could be applied to patient booking records to predict environmental radiation dose rates in these areas to aid prospective risk assessment calculations, which this proof-of-concept work investigates. 540 days of a dosimeters historical daily average dose rate measurements and the corresponding period of department therapy booking records were used to train six different ML models. Predicted versus measured daily average dose rates for the following 60 days were analysed to assess and compare model performance. A wide range in prediction errors was observed across models. The gradient boosting regressor produced the best accuracy (root mean squared error = 1.10 µSv.hr−1, mean absolute error = 0.87 µSv.hr−1, mean absolute percentage error = 35% and maximum error = 3.26 µSv.hr−1) and goodness of fit (R 2 = 0.411). Methods to improve model performance and other scenarios where this approach could prove more accurate were identified. This work demonstrates that ML can predict temporal fluctuations in environmental radiation dose rates in the areas surrounding radionuclide therapy wastewater pipework and indicates that it has the potential to play a role in improving legislative compliance, the accuracy of radiation safety and use of staff time and resources.

UK audit of variation in nuclear medicine occupational exposure calculations in 2021

It is a core requirement of UK ionising radiations regulations 2017 (IRR17) compliance for radiation risk assessments and the investigation of accidental exposure scenarios that the magnitude of doses likely to be encountered are evaluated. A novel national audit was undertaken to investigate the variation in dose estimations for a range of foreseeable accidental exposure scenarios in nuclear medicine (NM). Participants were asked to estimate the levels of exposure in 15 foreseeable scenarios; covering whole-body and extremity exposures from external sources, internal exposure and exposures from skin (surface contamination and needle-stick injury) and eye contamination. Questions were intentionally simplified to reduce variation from assumptions made by the participants and to focus more on the underlying gross systematic variation. Twenty-seven centres participated. There was generally a very wide variation in the estimated exposures across all the categories of exposures, apart from internal exposure estimates. Whilst there was no ground truth for each individual question, the variation in results itself often exceeded the relevant threshold for classification and annual dose limits. The majority of variation was due to differences in methods, models and assumptions used by each participant. This audit raises questions around how IRR17 compliance can be universally demonstrated with such wide national variation. It evidences the need for a more standardised practice in NM radionuclide exposure estimates through national consensus guidelines or standards etc.

Application of ALARP cost-benefit analysis to hospital-based radiation protection

The UK Ionising Radiations Regulations 2017 require employers to restrict radiation doses to their employees and the public to be as low as reasonably practicable (ALARP). This article looks at the boundary between what might be considered to be reasonable and unreasonable in protecting staff and the general public in the field of hospital-based diagnostic radiology. Guidance on cost-benefit analysis in support of ALARP has been used to formulate relationships for the estimation of the cost at which a radiation protection intervention is no longer ALARP. These relationships allow for a direct link between a reduction in radiation exposure and the maximum reasonable ALARP cost of intervention. Application of the approach to hospital-based radiation protection situations show that the ALARP cost limits for protecting radiation workers against the residual risks in the hospital environment are relatively low. Conversely, the ALARP limit to investment in public dose reduction by means of reducing patient doses can be very high.

“ADEQUACY OF CLINICAL INDICATION IN WARRANTING THE CECT THORAX AND ABDOMEN IN BLUNT TRAUMA INJURY FROM THE EMERGENCY DEPARTMENT.”

The RCR outlines indications for polytrauma CT imaging in severely injured patients. CT requests in the trauma setting should comply with the Ionising Radiation (Medical Exposure) Regulations justification regulations in the same way as any other request for imaging involving ionizing radiation. This study helps in reducing unjustifiable radiology CT imaging for polytrauma scans without an absolute clinical indication.

ALARP: when does reasonably practicable become rather pricey?

The Ionising Radiations Regulations 2017 require employers to restrict radiation doses to their employees and the public to be As Low As Reasonably Practicable. This article looks at the boundary between what might be considered to be reasonable and unreasonable in protecting staff and the general public in the field of hospital-based diagnostic radiology. A simple test for locating this boundary based on a cost-benefit approach is devised and its use illustrated using hospital-based radiation protection examples. It is concluded that a cost-benefit calculation based on the legal definition of As Low As Reasonably Practicable may have some use in the support of radiation protection decision-making in the hospital environment, but only within the context of existing legal, practical and ethical considerations.

Survey of the publics’ preferences for communication of medical radiation risk * * Funding provided from Health Education England as part of the Higher Specialist Scientist Training programme.

To comply with the Ionising Radiations (Medical Exposures) Regulations 2017, patients need to be adequately informed of medical radiation risks prior to exposure. This study used a survey developed in partnership with patients and members of the public to explore patient preferences for radiation risk communication. It was distributed through social media between 28/4/2020 and 18/7/2020. All respondents (N = 376) wanted to be informed about radiation risk, though the threshold at which they wished to be informed varied. The current practice of displaying posters in waiting areas does not meet the expressed preference of the patients if used in isolation. Only 6% of respondents were satisfied with the commonly used statement that the ‘risk is low’ if used in isolation. The majority of respondents (73%) said they would not be concerned about an increase in the risk of cancer of less than 1 in 10 000. The level of risk at which patients express a concern and the methodology for risk communication has been evaluated and based on these findings, and pre-existing literature, a graded approach to radiation risk communication based on modality is proposed. Patients must be involved throughout the evolution of this practice.

An update on radiation protection and the ionizing radiation regulations

In this article, the risks associated with dental X-ray examinations, the doses from different types of dental x-ray examinations, the principles of radiation protection and the key points set out in the IRR 17 and IRMER 17 legislation, with emphasis on the relevant changes between these new sets of legislation and the preceding IRR 99 and IRMER 2000 legislation, are considered. CPD/Clinical Relevance: An update and overview for the dental team on radiation protection and the relevant legislation.

The challenges of radioiodine treatment for incontinent paediatric patients with complex care needs.

A thyrotoxic paediatric patient with incontinence, autism and Down's syndrome was referred for radioiodine therapy. Here, the risk assessment methodology and measures taken to deliver a legally compliant treatment that was acceptable to the family are described. Prior risk assessment indicated that the most active incontinence waste would require decay storage until it could be transported for disposal. The Health and Safety Executive (HSE) indicated that school staff would be occupationally exposed under the Ionising Radiations Regulations (2017) based on the patient's retained activity. To avoid the need for HSE registration, it was advised that the patient's return to school may need to be delayed slightly. Post-treatment, confirmatory waste and patient dose rate measurements were made to refine the advised time scales. Domestic waste disposal resumed at 28 days. The patient recommenced schooling a few days after their school reopened after the summer break. The school underwent HSE notification. Careful planning allowed us to provide a safe, compliant treatment regarding waste management and occupational exposure. Incontinent 131I outpatient treatments require detailed, patient specific waste management. The HSE considered school staff as occupationally exposed by the patient well after normal social restrictions had ended.

Establishing local diagnostic reference levels for common orthopaedic procedures using the mini C-arm fluoroscope.

Mini C-arm fluoroscopes are widely used by orthopaedic surgeons for intraoperative image guidance without the need for radiographers. This puts the responsibility for radiation exposure firmly with the operating surgeon. In order to maintain safe and best practice under U.K. Ionising Radiation (Medical Exposure) Regulations, one must limit radiation exposure and audit performance using national diagnostic reference levels (DRLs). In the case of the mini C-arm, there are no national DRLs. IR(ME)R, therefore, require the establishment of local DRLs by each hospital to act as an alternative guideline for safe radiation use. The aim of our audit was to establish local DRLs based on our experience operating with the use of the mini C-arm over the last 7 years. This retrospective audit evaluates the end dose-area product (DAP) recorded for common trauma and orthopaedic procedures using the mini C-arm in a busy district general hospital.We present the quartile data and have set the cut-off point as the third quartile for formulating the local DRLs, consistent with the methodology for the conventional fluoroscope. For our data set (n = 1664), the third quartile DAP values were lowest for surgeries to the forearm (5.38 cGycm2), hand (7.62 cGycm2), and foot/ankle (8.56 cGycm2), and highest for wrist (10.64 cGycm2) and elbow (14.61 cGycm2) procedures. To our knowledge, this is the largest data set used to establish local DRLs. Other centres may find our guidelines useful whilst they establish their own local DRLs.

Managing Small Radioactive Collections in the UK: Experiences from the Polar Museum, Cambridge

Many collections in the UK include some radioactive objects, which must be managed in accordance with the Environmental Permitting Regulations and the Ionising Radiation Regulations. These laws are complex and cover a wide range of industries so it can be difficult to work out how they apply to museums in practice. Museums in the UK also have to consider how to integrate their legal obligations for working with radiation with accepted museum ethical guidelines, SPECTRUM 5.0 and the Accreditation Standard. This paper aims to illustrate how radioactive objects can be practically managed in a small museum context through examples from the Polar Museum in Cambridge, where the Radiation Protection team and the conservator have worked closely since 2009 to develop robust procedures. It covers many collections based activities including display, storage and conservation, and discusses these in the context of recent updates to UK law. A risk assessment template for working with radioactive collections is included as an Appendix.

New Regulations on X-Ray Use: Likely Implications of IRR17 and IRMER18.

Professor Keith Horner, co-editor of FGDP(UK)'s selection criteria for dental radiography, analyses what the ionising radiation regulations 2017 and draft ionising radiation (medical exposure) regulations 2018 mean for dentists and dental practice teams.

New regulations on X-ray use: likely implications for dental practices

Professor Keith Horner, University of Manchester, Co-editor of FGDP(UK)'s Selection criteria for dental radiography, has reviewed the draft Ionising Radiation Regulations 2017 and draft Ionising Radiation (Medical Exposure) Regulations 2018 and what they mean for dental practices.

UK guidance on the management of personal dosimetry systems for healthcare staff working at multiple organizations.

There has been concern expressed by the UK regulator, the Health & Safety Executive, regarding the management of occupation dose for healthcare radiation workers who work across multiple organizations. In response to this concern, the British Institute of Radiology led a working group of relevant professional bodies to develop guidance in this area. The guidance addresses issues of general system management that would apply to all personal dosimetry systems, regardless of whether or not the workers within that system work across organizational boundaries, along with exploring efficient strategies to comply with legislation where those workers do indeed work across organizational boundaries. For those specific instances, the guidance discusses both system requirements to enable organizations to co-operate (Ionising Radiation Regulations 1999 Regulation 15), as well as specific instances of staff exposure. This is broken down into three categories-low, medium and high risk. A suggested approach to each is given to guide employers and their radiation advisers in adopting sensible strategies for the monitoring of their staff and the subsequent sharing of dosimetry data to ensure overall compliance with both dose limits and optimization requirements.

Radiation protection training for cardiologists in the era of multiple imaging techniques and complex interventions.

Cardiologists are among the heaviest medical users of ionising radiation. This usage is growing in proportion to the expanding range of cardiac diagnostic tests and interventional treatments. The primary focus of cardiologists is achieving clear diagnoses as well as technically and clinically successful treatments. That has to be set alongside strong awareness of the properties of ionising radiation and associated safety issues. This article illustrates some of the interplay between contemporary cardiology, radiological techniques, cardiology training and ionising radiation regulations and aims to set context for training and accreditation of cardiologists who use ionising radiation.

Safe radiology for junior doctors: closed-loop audit

Background to the audit: Despite being the largest imaging requesting cohort, junior doctors’ awareness of the Ionising Radiation (Medical Exposure) Regulations (IR[ME]R) 2000 regulations and their relevance to radiology requesting is unclear.1

The effects of device position on the operator's radiation dose when using a handheld portable X-ray device.

Handheld X-ray devices are now offered in dental practice. Handheld X-ray units challenge the concept of a restricted access to the "controlled area" as they are held by the operator. Although an integral lead shield is provided, the distance from the body is variable, dependent on how the device is held. The aim of this article was to investigate the level of operator dose when using a handheld X-ray device in various positions. A NOMAD Pro™ Handheld X-ray system (Aribex Inc., Charlotte, NC) fitted with a remote control and mounted on a tripod was used in this study. A maxillofacial phantom ATOM(®) Max Dental and Diagnostic Phantom, model 711 HN (CIRS Inc., Norfolk, VA) was used to simulate the patient's head position. A mannequin was used to represent the operator. Pre-calibrated thermoluminescent dosemeters (TLDs) (Qados, Agar Scientific, Stansted, UK) were placed on the mannequin close to the eyes and at the level of thyroid, trunk, waist, hand (right finger + left palm) and feet, and three TLDs were used for background radiation. Three test scenarios were investigated; Position 1, close to operators' body and parallel to the ground; Position 2, away from the body with the arms fully extended (approximately 40 cm distance) and parallel to the ground; Position 3, perpendicular to the ground while the arms are partially extended. 30 exposures each of 1 s were performed in each test. Background radiation was measured at 0.0110 mGy. The highest exposure after subtracting background radiation was recorded on the palm of the left hand (0.0310 mGy) at Position 3. The estimated dose to the operator was calculated based on an average workload of 100 intraoral radiographs weekly for a dental practitioner working 46 weeks a year. There is a negligible increase in operator exposure levels using handheld X-ray devices which remain well below the recommended levels of the Ionizing Radiation Regulations 1999. They could however represent an increase from what should be a nil exposure when using a wall-mounted machine. The position of the device relative to the operator has a significant effect on the overall operator's radiation exposure. The use of personal dosemeters is highly recommended to ensure a continuity of low radiation dose exposure. Furthermore, guidance, training and protocols on usage must be in place, strictly adhered to and regular audits are necessary to ensure compliance.