Synthesis of the European ALARA network 20th workshop 'ALARA for interventional radiology and nuclear medicine'.

The European as low as reasonably achievable(ALARA) network regularly organises workshops on topical issues in radiation protection (RP). The topic of the 20th workshop was: 'ALARA for interventional radiology (IR) and nuclear medicine (NM)'. The objective was to examine the challenges faced when applying the optimisation principle (ALARA) in IR and NM and to consider how ALARA could be better implemented for patient and staff exposures. This memorandum provides a synthesis of the workshop sessions, and recommendations coming from the working groups discussion. Parallels are drawn with the recommendations arising from the 13th EAN workshop on 'ALARA and the medical sector (2011)' to consider how the optimisation challenges in IR and NM have evolved over the past decade. Current levels of exposure are presented along with operational practice and the challenges and opportunities for improvement, both in monitoring and practice. Whilst RP challenges remain, the application of ALARA appears more established in IR compared with experiences reported in 2011. The application of ALARA to emerging technologies in the NM setting is in need of further development to ensure that RP is considered at all stages in the development process of new radiopharmaceuticals. Besides the obvious technical and operational aspects, the importance of education and training, human factors and broadly the RP 'culture' were deemed fundamental to the success of the application of ALARA and where further emphasis is needed. All concerned parties, medical physics experts (MPEs), radiation protection experts, clinical staff, manufacturers and regulators have a role to play in the application of ALARA and this is discussed in the memorandum. Many of the recommendations from the 13th EAN workshop remain applicable today and overlap with the recommendations arising from the 20th workshop. This should prompt attention given that the use of IR and the development of novel radiopharmaceuticals for NM is only anticipated to increase with time.

Comparison of shielding effects of over-glasses-type and regular eyewear in terms of occupational eye dose reduction.

Given the new recommendations for occupational eye lens doses, various lead glasses have been used to reduce irradiation of interventional radiologists. However, the protection afforded by lead glasses over prescription glasses (thus over-glasses-type eyewear) has not been considered in detail. We used a phantom to compare the protective effects of such eyewear and regular eyewear of 0.07 mm lead-equivalent thickness. The shielding rates behind the eyewear and on the surface of the left eye of an anthropomorphic phantom were calculated. The left eye of the phantom was irradiated at various angles and the shielding effects were evaluated. We measured the radiation dose to the left side of the phantom using RPLDs attached to the left eye and to the surface/back of the left eyewear. Over-glasses-type eyewear afforded good protection against x-rays from the left and below; the average shielding rates on the surface of the left eye ranged from 0.70-0.72. In clinical settings, scattered radiation is incident on physicians' eyes from the left and below, and through any gap in lead glasses. Over-glasses-type eyewear afforded better protection than regular eyewear of the same lead-equivalent thickness at the irradiation angles of concern in clinical settings. Although clinical evaluation is needed, we suggest over-glasses-type Pb eyewear even for physicians who do not wear prescription glasses.

Individual patient radiation dose tracking: Perceptions of radiographers in South Africa.

INTRODUCTION: Medical imaging examinations that make use of ionising radiation provide valuable information towards patient management. Literature suggests that there is a significant rise in the number of patient referrals for such examinations. The concept "individual patient radiation dose tracking" (IPRDT) is introduced to optimise radiation monitoring. Many countries across the globe explored and implemented methods to enhance and promote the justification and optimisation principles essential for patient radiation safety. In South Africa (SA), however, attention to IPRDT is limited. METHODS: A qualitative research design was employed. Radiographers in the Western Cape Province of SA were purposefully sampled for participation in one-on-one, semi-structured interviews. Thematic analysis was applied to the transcribed interview data. RESULTS: This paper presents a theme developed from the radiographer cohort of ten (10) participants. The theme: the need for creating awareness and implementing legislative support structures, was developed from the data, with the following supporting subthemes: 1) stakeholder awareness and 'buy-in' 2) continuous professional development and 3) mandated practice. CONCLUSION: This study provides findings that are of value for patient radiation safety in SA by giving a voice to local stakeholders. Other countries that are conducting similar research investigations toward the integration of an IPRDT model, method, or framework, may also benefit from these findings. IMPLICATIONS FOR PRACTICE: The effective integration of IPRDT into the clinical environment requires unison amongst the relevant stakeholders and clarity on the various professionals' roles and responsibilities. The findings of this study furthermore suggest the involvement of regulatory organisations for the provision of a mandated form of practice at national and international levels.

Relationship between assistant's lens exposure and dose information during computed tomography examinations.

According to International Commission of Radiological Protection, the equivalent dose limit for the eye lens for occupational exposure is recommended to be 20 mSv yr-1, averaged over 5 years, with no single year above 50 mSv. Some studies reported the measurement of assistant's lens exposure in diagnostic computed tomography (CT) examinations, but further investigation is still required in the association between the lens dose for assistants and various dose parameters. Therefore, we measured the assistant's lens exposure using small optically stimulated luminescence dosimeters. The type of occupation, type of assistance, total scan time, total mAs, total scan length, and dose-length product (DLP) were recorded and analyzed in association with air kerma at the lens position. The assistance was classified into four types: 'assisted ventilation,' 'head holding,' 'body holding,' and 'raising patient's arm.' The air kerma of lens position was not significantly different for each assistance type (p< 0.05, Kruskal-Wallis test). Further, the lens doses for assistants correlated with DLP, but with various strengths of correlation with the assistance type and were influenced by the distance from the CT gantry. In conclusion, lens dose during assistance and DLP demonstrated the strongest correlation. 'Raising patient's arm' and 'head holding' exhibited stronger correlations, which required less table movement during the CT scan than 'assisted ventilation' and 'body holding'.

RFPID: development and 3D-printing of a female physical phantom for whole-body counter.

Whole-body counters (WBC) are used in internal dosimetry forin vivomonitoring in radiation protection. The calibration processes of a WBC set-up include the measurement of a physical phantom filled with a certificate radioactive source that usually is referred to a standard set of individuals determined by the International Commission on Radiological Protection (ICRP). The aim of this study was to develop an anthropomorphic and anthropometric female physical phantom for the calibration of the WBC systems. The reference female computational phantom of the ICRP, now called RFPID (Reference Female Phantom for Internal Dosimetry) was printed using PLA filament and with an empty interior. The goal is to use the RFPID to reduce the uncertainties associated within vivomonitoring system. The images which generated the phantom were manipulated using ImageJ®, Amide®, GIMP®and the 3D Slicer®software. RFPID was split into several parts and printed using a 3D printer in order to print the whole-body phantom. The newly printed physical phantom RFPID was successfully fabricated, and it is suitable to mimic human tissue, anatomically similar to a human body i.e., size, shape, material composition, and density.

Development of shielding evaluation and management program for O-ring type linear accelerators.

The shielding parameters can vary depending on the geometrical structure of the linear accelerators (LINAC), treatment techniques, and beam energies. Recently, the introduction of O-ring type linear accelerators is increasing. The objective of this study is to evaluate the shielding parameters of new type of linac using a dedicated program developed by us named ORSE (O-ring type Radiation therapy equipment Shielding Evaluation). The shielding evaluation was conducted for a total of four treatment rooms including Elekta Unity, Varian Halcyon, and Accuray Tomotherapy. The developed program possesses the capability to calculate transmitted dose, maximum treatable patient capacity, and shielding wall thickness based on patient data. The doses were measured for five days using glass dosimeters to compare with the results of program. The IMRT factors and use factors obtained from patient data showed differences of up to 65.0% and 33.8%, respectively, compared to safety management report. The shielding evaluation conducted in each treatment room showed that the transmitted dose at every location was below 1% of the dose limit. The results of program and measurements showed a maximum difference of 0.003 mSv/week in transmitted dose. The ORSE program allows for the shielding evaluation results to the clinical environment of each institution based on patient data.

Medical staff dose estimation during pediatric cardiac interventional procedures.

The purpose of this study is to evaluate the occupational doses (eye lens, extremities and whole body) in paediatric cardiac interventional and diagnostic catheterization procedures performed in a paediatric reference hospital located in Recife, Pernambuco. For eye lens dosimetry, the results show that the left eye receives a higher dose than the right eye, and there is a small difference between the doses received during diagnostic (D) and therapeutic (T) procedures. The extrapolated annual values for the most exposed eye are close to the annual limit. For doses to the hands, it was observed that in a significant number of procedures (37 out of 45 therapeutic procedures, or 82%) at least one hand of the physician was exposed to the primary beam. During diagnostic procedures, the physician's hand was in the radiation field in 11 of the 17 catheterization procedures (65%). This resulted in a 10-fold increase in dose to the hands. The results underscore the need for optimization of radiation safety and continued efforts to engage staff in a radiation safety culture.

Managing radiation safety and protection in gastroenterology in Japan: insights from the REX-GI study.

Fluoroscopy-guided gastrointestinal procedures, including gastrointestinal stenting, balloon-assisted endoscopy (BAE), endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasound (EUS), are essential for diagnosis and treatment in gastroenterology. Such procedures involve radiation exposure that necessitates strict safety measures to protect patients, doctors, and medical staff. The April 2020 update to Japan's Ionizing Radiation Injury Prevention Regulations for occupational exposure reduced the lens exposure dose limit to approximately one-seventh of its previous level. This change highlights the need for improved safety protocols. Without adaptation, the sustainability of fluoroscopy-based endoscopic techniques could be at risk due to the potential to exceed these new limits. This review examines the current state of medical radiation exposure in the field of gastroenterology in Japan and discusses the findings of the REX-GI study.

Alerts to improve occupational protection during Interventional Radiology. More attention is needed for simple but frequent procedures.

Occupational protection could be improved in interventional radiology. The monthly personal dosimetry cannot alert on some occupational doses with anomalous values for certain procedures. Active electronic personal dosimeters linked wireless to a dose management system (DMS), allow for the measurement of occupational doses per procedure, integrating this information with patient dose indicators and with technical and geometrical conditions of the procedures. We analysed around 3100 occupational dose values for individual procedures collected during the last two years, in an interventional radiology laboratory of a University Hospital and two groups, with patient doses higher than 100 Gy.cm2, and lower than 30 Gy.cm2. An unshielded reference dosimeter located at the C-arm registers the ambient dose equivalent (ADE) per procedure to be compared with the personal dose equivalent (PDE) over the apron. The ratio between both values PDE/ADE is a good indication of occupational protection. Alerts for occupational protection optimisation are suggested. For the full sample, 8.4 % of occupational doses measured over the protective apron of the interventionists were higher than 100 µSv and 3.8 % higher than 200 µSv per procedure. Occupational protection for complex procedures (>100 Gy.cm2) had median values of 46 µSv for PDE and 3.3 % for PDE/ADE. However, for simple procedures, (<30 Gy.cm2) the median values were 10 µSv and 28.4 %. This last percentage is 9 times higher than the value for complex procedures. This lack of protection should be corrected and the need to reduce some occupational doses reinforced in radiation protection training programmes for interventionists.

Radiological complexity of nuclear facilities: an information complexity approach to workplace monitoring.

Nuclear energy is crucial for achieving net-zero carbon emissions. A big challenge in the nuclear sector is ensuring the safety of radiation workers and the environment, while being cost-effective. Workplace monitoring is key to protecting workers from risks of ionising radiation. Traditional monitoring involves radiological surveillance via installed radiation monitors, continuously recording measurements like radiation fields and airborne particulate radioactivity concentrations, especially where sudden radiation changes could significantly impact workers. However, this approach struggles to detect incremental changes over a long period of time in the radiological measurements of the facility. To address this limitation, we propose abstracting a nuclear facility as a complex system. We then quantify the information complexity of the facility's radiological measurements using an entropic metric. Our findings indicate that the inferences and interpretations from our abstraction have a firm basis for interpretation and can enhance current workplace monitoring systems. We suggest the implementation of a radiological complexity-based alarm system to complement existing radiation level-based systems. The abstraction synthesized here is independent of the type of nuclear facility, and hence is a general approach to workplace monitoring at a nuclear facility.

A Review of Recent Low-dose Research and Recommendations for Moving Forward.

ABSTRACT: The linear no-threshold (LNT) model has been the regulatory "law of the land" for decades. Despite the long-standing use of LNT, there is significant ongoing scientific disagreement on the applicability of LNT to low-dose radiation risk. A review of the low-dose risk literature of the last 10 y does not provide a clear answer, but rather the body of literature seems to be split between LNT, non-linear risk functions (e.g., supra- or sub-linear), and hormetic models. Furthermore, recent studies have started to explore whether radiation can play a role in the development of several non-cancer effects, such as heart disease, Parkinson's disease, and diabetes, the mechanisms of which are still being explored. Based on this review, there is insufficient evidence to replace LNT as the regulatory model despite the fact that it contributes to public radiophobia, unpreparedness in radiation emergency response, and extreme cleanup costs both following radiological or nuclear incidents and for routine decommissioning of nuclear power plants. Rather, additional research is needed to further understand the implications of low doses of radiation. The authors present an approach to meaningfully contribute to the science of low-dose research that incorporates machine learning and Edisonian approaches to data analysis.

Occupational orthopedic problems and its relation to personal radiation protection in interventional radiology.

PURPOSE: Several studies report occupational orthopedic problems among interventional cardiologists. These health problems are usually multifactorial. However, the personal protective equipment used should play a major role. An online survey was conducted to determine the frequency of such health problems among interventional radiologists and to correlate them with the use of personal radiation protective clothing. MATERIAL AND METHODS: An anonymous online survey that comprised of 17 questions was sent via e-mail to 1427 members of the German Society for Interventional Radiology (DeGIR) in Germany, Austria and Switzerland. The questions were focused on interventional workload, the use of personal radiation protection apparel and orthopedic problems. Given the different scale levels, the associations between the variables were analyzed using different statistical methods. A significance level of p < 0.05 was chosen. RESULTS: There were 221 survey responders (15.5% response rate). About half of responders (47.7%) suffered from more than five episodes of orthopedic problems during their interventional career. Lumbar spine was involved in 81.7% of these cases, cervical spine in 32.8%, shoulder in 28.5% and knee in 24.7%. Because of orthopedic problems, 16.1% of the responders had to reduce and 2.7% had to stop their interventional practice. The number of affected body regions correlates with the fit of the radiation protection means (p < 0.05, r = 0.135) and the reduction of activity as an interventional radiologist (p < 0.05, r = -0.148). CONCLUSION: Overall, the survey reveals widespread orthopedic problems at several body regions among interventional radiologists, associated with the fit of radiation protection systems, among other factors. A connection between the orthopaedic complaints and the radiation protection system used could not be established.

Prospective dose monitoring using a manual dose management system: experience in brain computed tomography from a tertiary hospital in Nigeria.

A manual radiation dose management system was developed to track the radiation dose and scan parameters of patients for brain computed tomography (CT). Radiation dose in volume computed tomography dose index (CTDIvol) and dose length product (DLP) were monitored to identify procedures that may require optimisation using notification values. The data were analysed and compared with national and international diagnostic reference levels (DRLs). A total of 596 brain CTs were monitored and grouped as <1: 36, 1-<5: 38, 5-<10: 25, 10-<15: 31 and adult: 466. The CTDIvol notification value identified the following number of examinations having high CTDIvol in <1 y: 1, 1-<5: 1, 5-<10: 0, 10-<15: 0 and adult (>15): 11. Furthermore, the DLP notification values identified the following examinations with high DLP in <1 y: 1, 1-<5:1, 5-<10:1, 10-<15: 1 and adults (>15): 18. The established local paediatric DLP DRLs were 2-3 times higher than the international paediatric DLP DRLs. This calls for a total protocol review and optimisation considering the local CT practices for paediatric imaging.

Patient perspectives on ionising radiation exposure from computed tomography in Saudi Arabia: a knowledge and perception study.

The objective of this study was to evaluate patient knowledge and understanding of ionising radiation and dosage, as well as the accompanying risks related to computed tomography scans. A total of 412 outpatients who underwent computed tomography (CT) scans were surveyed to assess their understanding of radiation dose and exposure risks. CT was correctly classified as an ionising radiation by 56.8% of the respondents. More than half of the patients reported that a CT scan increases the probability of inducing cancer. Awareness of varying radiation doses in different CT exams was noted in 75.2% of patients, but only 21.4% reported having discussions with their physician about radiation dose. Gender, age and employment were significantly correlated with knowledge levels. The survey findings indicate a limited understanding of the hazards associated with ionising radiation used in CT scans, highlighting a need for increased awareness and education on radiation protection to ensure informed consent.

Potential risk assessment: a model for quality evaluation in fluoroscopy-guided interventional procedures.

This study presented a model applied for potential risk assessment in an interventional radiology setting. The model of potential risk assessment (MARP) consisted of the creation of a scale of indicators ranging from 0 to 5. The radiation levels were categorized according to gender, kind of procedure, value of kerma air product (Pka), and accumulated radiation dose (mGy). The MARP model was applied in 121 institutions over 8 y. A total of 201 656 patient radiation doses (Dose-area product and accumulated kerma) data were launched into the system over time, with an average of 22 406 doses per year. In the context of the workers (cardiologists, radiographers, and nurses) monitored during the MARP application, 8007 cases (with an average of 890 per year) of occupational radiation doses were recorded. This study showed a strategy for quality evaluation in fluoroscopy using a model with a compulsory information system for monitoring safety.

NCRP commentary no. 33-recommendations for stratification of equipment use and radiation safety training for fluoroscopy.

National Council on Radiation Protection and Measurements Commentary No. 33 'Recommendations for Stratification of Equipment Use and Radiation Safety Training for Fluoroscopy' defines an evidence-based, radiation risk classification for fluoroscopically guided procedures (FGPs), provides radiation-related recommendations for the types of fluoroscopes suitable for each class of procedure, and indicates the extent and content of training that ought to be provided to different categories of facility staff who might enter a room where fluoroscopy is or may be performed. For FGP, radiation risk is defined by the type and likelihood of radiation hazards that could be incurred by a patient undergoing a FGP. The Commentary also defines six training groups of facility staff based on their role in the fluoroscopy room. The training groups are based on a combination of job descriptions and the procedures in which these individuals might be involved. The Commentary recommends the extent and content of training that should be provided to each of these training groups. It also provides recommendations on training formats, training frequency, and methods for demonstrating that the learner has acquired the necessary knowledge.