As Low As Reasonably Achievable Research Articles

In vivo demonstration of a real-time temporal SNR acoustic output adjustment method.

This work proposes a novel method of temporal signal-to-noise ratio (SNR) guided adaptive acoustic output adjustment and demonstrates this approach during in vivo fetal imaging. Acoustic output adjustment is currently the responsibility of sonographers, but ultrasound safety studies show recommended ALARA (As Low As Reasonably Achievable) practices are inconsistently followed. This study explores an automated ALARA method that adjusts the Mechanical Index (MI) output, targeting imaging conditions matching the temporal noise perception threshold. A 28 dB threshold SNR is used as the target SNR, following prior work showing relevant noise quantities are imperceptible once this image data quality level is reached. After implementing adaptive output adjustment on a clinical system, the average MI required to achieve 28 dB SNR in an eleven-volunteer fetal abdomen imaging test ranged from 0.17 to 0.26. The higher MI levels were required when imaging at higher frequencies. During tests with 20-second MI adjustment imaging periods, the degree of motion impacted the adaptive performance. For stationary imaging views, target SNR levels were maintained in 90% of SNR evaluations. When scanning between targets the imaging conditions were more variable, but the target SNR was still maintained in 71% of the evaluations. Given the relatively low MI recommended when performing MI adjustment and the successful adjustment of MI in response to changing imaging conditions, these results encourage adoption of adaptive acoustic output approaches guided by temporal SNR.

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.

Commissioning of the first hospital-based PET radiopharmaceutical cyclotron in Greece: Personnel dose assessment.

The role of positron emission tomography (PET) imaging with 2-fluoro-2-deoxy-D-glucose (FDG) is well established in the diagnosis and management of cancer patients. As the demand for PET imaging continues to rise, many hospitals are installing on-site self-shielded mini cyclotrons to produce their own radiopharmaceuticals, including FDG. In May 2021, the Dose-on-Demand Biomarker Generator (BG-75) was installed at the Metaxa Cancer Hospital in Greece, making it the first hospital-based PET radiopharmaceutical cyclotron in the country. During commissioning, the expected external exposure for personnel was established, and internal exposure was found to be negligible. Personnel dose was estimated with two methods: survey meter measurements in various locations combined with the time spent in each location, and direct measurement using electronic personal dosemeters. Gamma and neutron radiation readings outside the cyclotron vault were at background levels. Inside the cyclotron vault, the highest recorded readings by the target were 18 μSv/h for both gammas and neutrons; at one meter, the values were 5 μSv/h and 4 μSv/h, respectively. Based on these measurements, the annual expected whole-body dose per operator is 0.6 mSv, and the respective extremity dose is 16 mSv. The annual expected whole body and extremity dose for the radiochemist is 0.3 mSv and 25 mSv, respectively. The expected dose estimates for the medical physicists are also below 1 mSv. These doses are well below the regulatory limits and local As Low As Reasonably Achievable (ALARA) levels. With experience and a robust ALARA program, personnel exposure could be further reduced.&#xD.

Radiation exposure of patients during endourological procedures.

Considering the existing gaps in the literature regarding patient radiation dose (RD) and its associated risks, a systematic review of the literature on RD was conducted, focusing on percutaneous nephrolithotomy (PCNL), extracorporeal shock wave lithotripsy (SWL), and ureteroscopy (URS). Two authors conducted a literature search on PubMed, Web of Science, and Google Scholar to identify studies on RD during endourological procedures. Two thousand two hundred sixty-six articles were screened. Sixty-five publications met the inclusion criteria using the PRISMA standards. RD was generally highest for PCNL, reaching levels up to 33mSv, 28,700 mGycm2, and 430.8mGy. This was followed by SWL, with RD reaching up to 7.32mSv, 13,082 mGycm2, and 142mGy. URS demonstrated lower RD, reaching up to 6.07mSv, 8920 mGycm2, and 46.99mGy. Surgeon experience and case load were inversely associated with RD. Strategies such as optimizing fluoroscopy settings, implementing ultrasound (US), and following the ALARA (As Low As Reasonably Achievable) principle minimized RD. This is the first systematic review analyzing RD, which was generally highest during PCNL, followed by SWL and URS. There is no specific RD limit for these procedures. Implementation of strategies such as optimizing fluoroscopy settings, utilizing US, and adhering to the ALARA principle proved effective in reducing RD. However, further research is needed to explore the factors influencing RD, assess their impact on patient outcomes, and establish procedure-specific reference levels for RD.

Radiation exposure to the orthopedic surgeon-a dosimetric comparison of two mini C-arm fluoroscopy models: a pilot study.

Perform a cadaveric experimental pilot study to measure and compare potential radiation exposure to an orthopedic surgeon from 2 different-generation mini C-arm models during a simulated orthopedic surgery. 16 radiation dosimeters. Mock surgery setups were constructed with a canine cadaver thoracic limb and 2 different-generation mini C-arm models. Four radiation dosimeters were placed near the mini C-arm to mimic common locations of radiation exposure during image acquisition. One mini C-arm was placed in auto technique mode, and 100 static images were acquired. The dosimeters were replaced, and a 5-minute-long dynamic image was acquired. The same protocols were repeated for the second mini C-arm. The dosimetry badges were then submitted for radiation exposure quantification. All but 1 dosimeter had radiation exposure levels below the detectable limits of the dosimeter. The dosimeter closest to the primary x-ray beam of 1 mini C-arm during dynamic image acquisition had a reading of 1 mrem. Intraoperative radiation exposure from the mini C-arm is low, specifically to areas not protected by lead and in close proximity to the primary x-ray beam. That being said, surgeons should always practice the principles of ALARA (ie, as low as reasonably achievable) to minimize radiation exposure in the workplace.

Radiation protection knowledge and practices among Moroccan dentists: A cross-sectional study

ObjectiveTo analyze the current status of knowledge and practices among the Moroccan dentists in the region of Rabat-Salé-Kenitra, towards radiation protection. MethodsThis is a cross-sectional study based on a questionnaire related to knowledge and practice regarding radiation protection of patients and dental staff from April to June 2022. The study sample included 325 dentists practicing in the Rabat-Salé-Kénitra region. The target population consisted of all dentists working in public, semi-public and private workplaces. Results96.6% of dentists were aware of radiation protection. However, nearly 35% were aware of ALARA (as low as reasonably achievable) principle and 73.9% thought that dental X-rays are harmful. 63.6%of subjects used digital image receptor. Only 16.7% of them used a film holder and more than 60% didn't follow the position and distance rule. The median knowledge score was 7 [5, 9], and there was a statistically significant difference according to dentist qualification (P ​= ​0.007), dental radiation protection continuous training (P ​< ​0.0001), age (P ​= ​0.007) and years of experience (P ​= ​0.039). The median practice score was 5 [4, 6] and there was a statically significance association according to workplace setting (P ​= ​0.001). There was a significant positive relationship between knowledge score and practice score (r ​= ​0.24, P<0.0001). Dentist qualification (OR 0.51, 95%CI: 0.27–0.94, P ​= ​0.03) and continuous training (OR 2.40, 95%CI: 1.47–3.93, P<0.0001) were significant predictors of knowledge, while workplace setting (OR 0.54, 95%CI: 0.32–0.93, P ​= ​0.027) and knowledge score (OR 1.24, 95%CI: 1.12–1.38, P<0.0001) were predictors of practices. ConclusionImproving dentists' knowledge of radiation protection measures and tools as well as dose reduction techniques could increase their safe practices in dental radiology.

Impact of Reducing Fluoroscopy Pulse Rate on AdultModified Barium Swallow Studies.

Modified Barium Swallow Studies (MBSS) are a critical part of the evaluation, treatment planning, and outcome assessment for persons with swallowing disorders. Since MBSSs use ionizing radiation with associated cancer risks, many clinicians have reduced radiation exposure by reducing the fluoroscopic pulse rate. However, by reducing pulse rate, we also decrease the temporal resolution of MBSSs which has been shown in pilot studies to significantly reduce diagnostic accuracy. Two hundred MBSSs from patients routinely undergoing MBSS as standard of care conducted at 30 pulses per second (pps) using the Modified Barium Swallow Study Impairment Profile (MBSImP™) standardized administration protocol were selected. A stratified sampling method ensured that a full range of swallowing impairments (etiology, type, and severity) was represented. Recordings were down sampled from 30 pps to 15, 7.5, and 4 pps. MBSSs were rated using the MBSImP components and Penetration-Aspiration Scale (PAS) score for each swallow. Percent agreement was calculated across raters for MBSImP and PAS scores by bolus type and volume. The Least-Squares Method was used for hypothesis testing. Statistically significant and clinically meaningful changes in scores of swallowing physiology and penetration/aspiration occurred when reducing pulse rate below 30pps. These changes were evident across bolus types and volumes. Given the impact on diagnostic accuracy and the low radiation risks to adults undergoing MBSSs, reducing pulse rate to 15pps or below is not aligned with the As Low As Reasonably Achievable (ALARA) principle and should not be used as a viable method to reduce radiation exposure from MBSSs.

Evaluation of organ dose using size-specific dose estimation (SSDE) and related cancer risk due to chest CT scan during the COVID-19 pandemic.

This study aimed to estimate lung and breast doses for individual patients using the size-specific dose estimate (SSDE) method, as well as calculating effective doses, in patients who underwent chest CT scans during the COVID-19 pandemic. Cancer risk incidence was estimated using excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) models from the Biological Effects of Ionizing Radiation Report VII (BEIR-VII). Data from about 570 patients who underwent CT scans for COVID-19 screening were utilized for this study. Using the header of the CT images in a Python script, SSDE and effective dose were calculated for each patient. The SSDE obtained by water equivalent effective diameter (wSSDE) was considered as lung and breast dose, and applied in organ-specific cancer risk estimation. The mean wSSDE value for females (13.3mGy) was slightly higher than that for males (13.1mGy), but the difference was not statistically significant (P value=0.41). No significant differences were observed between males and females in terms of calculated EAR and ERR for lung cancer at 5 and 30years after exposure (P value=0.47, 0.46, respectively). Similarly, there was no significant difference in lung cancer LAR values between females and males (P value=0.48). The results also indicated a decrease in LAR values for both lung and breast cancers with increasing exposure age. In accordance with the ALARA (as low as reasonably achievable) principle, it is important for medical staff and the general public to consider the benefits of CT imaging in detecting such infections. Additionally, imaging medical physicists and CT scan experts should optimize imaging protocols and strike a balance between image quality for detecting abnormalities and radiation dose, all while adhering to the ALARA principle.

Optimization of the "Perth CT" Protocol for Preoperative Planning and Postoperative Evaluation in Total Knee Arthroplasty.

Background and Objectives: Total knee arthroplasty (TKA) has become the treatment of choice for advanced osteoarthritis. The aim of this paper was to show the possibilities of optimizing the Perth CT protocol, which is highly effective for preoperative planning and postoperative assessment of alignment. Materials and Methods: The cross-sectional study comprised 16 patients for preoperative planning or postoperative evaluation of TKA. All patients were examined with the standard and optimized Perth CT protocol using advance techniques, including automatic exposure control (AEC), iterative image reconstruction (IR), as well as a single-energy projection-based metal artifact reduction algorithm for eliminating prosthesis artifacts. The effective radiation dose (E) was determined based on the dose report. Imaging quality is determined according to subjective and objective (values of signal to noise ratio (SdNR) and figure of merit (FOM)) criteria. Results: The effective radiation dose with the optimized protocol was significantly lower compared to the standard protocol (p < 0.001), while in patients with the knee prosthesis, E increased significantly less with the optimized protocol compared to the standard protocol. No significant difference was observed in the subjective evaluation of image quality between protocols (p > 0.05). Analyzing the objective criteria for image quality optimized protocols resulted in lower SdNR values and higher FOM values. No significant difference of image quality was determined using the SdNR and FOM as per the specified protocols and parts of extremities, and for the presence of prothesis. Conclusions: Retrospecting the ALARA ('As Low As Reasonably Achievable') principles, it is possible to optimize the Perth CT protocol by reducing the kV and mAs values and by changing the collimation and increasing the pitch factor. Advanced IR techniques were used in both protocols, and AEC was used in the optimized protocol. The effective dose of radiation can be reduced five times, and the image quality will be satisfactory.

DETERMINATION OF GROSS ALPHA/BETA RADIOACTIVITY OF WATER SAMPLES AROUND MINING SITES, DANGE-SHUNI LGA, SOKOTO STATE

Mining activities in the Iullumeden (Sokoto) basin is often heard of due to its prominence in artisanal mode of ransacking the Earth in search of minerals and metal of high economic values. The unabated demand in the growing post-industrial era have decimated any health impact that could be borne by the inhabitants of the mining communities. Dange-Shuni is an enclave of this basin that was covered in a bid to determine the gross alpha and beta radioactivity in domestic water in and around mining points. Water samples were collected and analyzed via Hidex 300 SL system of Liquid Scintillation Counting from a systematic sampling of fifteen mining points. The results indicate that both the gross alpha and beta radioactivity concentrations were in elevation with about 80% and 85% above the global limits of 0.5 and 1.0 . The results are good reasons to work hard in order to bring dose of radioactivity exposure to the inhabitants to as low as reasonably achievable (ALARA) being a mandate of WHO.

Is cross-sectional imaging necessary for fractures of the distal lower leg in children and adolescents: results of a nationwide survey.

In childhood and adolescence, cross-sectional imaging, most commonly computed tomography (CT), is often performed for advanced diagnosis of joint injuries of the distal lower leg and upper ankle. Due to radiation exposure, the need for CT remains controversial, as these injuries follow stereotypies and usually have a similar course. Alternatively, the performance of magnetic resonance imaging (MRI) is also discussed. Since radiation sensitivity at this young age is much higher than in adults, an effort must be to minimize radiation exposure according to as low as reasonably achievable (ALARA) principles. The aim of this survey is to evaluate the current procedure in Germany in the diagnosis of pediatric injuries of the distal lower leg and upper ankle. For data collection, a survey entitled "CT in fractures of the ankle joint in childhood and adolescence: subject of the survey are injuries between 8 and 15years of age" of the Section of Pediatric Traumatology in the German Association of Trauma Surgery was sent to all members via the distribution list of the German Society of Orthopedics and Traumatology and the distribution list of the German Society of Pediatric Surgery in a period from September 20, 2022-December 21, 2022. The survey included a total of 21 questions. Target groups were trauma and pediatric surgeons and orthopedic surgeons working in the hospital and in practice. A total of 525 participants took part in the survey: ultrasound diagnostics are used by almost 25% and the Ottawa Ankle Rules by over 50% always or in most cases. A conventional x-ray is always or most often used by over 90%. CT imaging is rarely used by 88.57%, mainly for surgical planning or analysis of fracture progression. 69.9% report that their radiology department uses a pediatric protocol for CT exams; 25.71% do not know if this is the case. MRI imaging is also used infrequently by 89.33%, mostly to identify associated injuries. Overall, CT imaging is chosen by 55.62% and MRI imaging by 35.24% as the sectional imaging modality for suspected fractures; 95.05% consider sectional imaging useful for a triplane fracture, 59.24% for a two-plane fracture, 41.71% for a Salter-Harris type III/IV injury, and 8% for a Salter-Harris type I/II injury. The survey showed that the conventional X-ray is still the gold standard. Interestingly, more than half of the respondents regularly use the Ottawa Ankle Rules, and diagnostics using ultrasound are also used by almost a quarter. Awareness of radiation protection in children exists, although a quarter of all participants do not know the extent to which their radiology department has a specific pediatric protocol for CT imaging. Cross-sectional imaging is performed on a regular basis. Regarding the actual extent of imaging, there is a clear divergence between theory and practice.

Indoor radon concentration levels in some selected offices at Ibrahim Badamasi Babangida University, Lapai, Nigeria and its attendant annual effective dose

Although radon concentrations in outdoor environments are generally low, the indoor concentrations can become appreciably high thereby affecting the indoor air quality and causing some severe health challenges. Thirty (30) offices from the ground floor and first floor of some buildings within Ibrahim Badamasi Babangida (IBB) University campus, Lapai Nigeria, were randomly selected for indoor radon concentration (CRn) measurement using RAD7 continuous radon monitor. Annual effective dose was also computed to determine the level of public exposure. The results showed that radon concentration values for all the offices on the ground floor ranged between 9.6±2.7 Bqm−3 and 90.7±8.1 Bqm−3, with mean value of 28.5±4.8 Bqm−3 while the range of radon concentration at first floor was 2.5±1.4 Bqm−3 - 80.4±7.5 Bqm−3. All the measured indoor radon concentration levels were less than the 100 Bqm−3 action level proposed by World Health Organization (WHO). Average annual absorbed dose for both ground and first floors were 0.36±0.06 mSvy−1 and 0.24±0.05 mSvy−1 respectively, with corresponding mean annual effective dose of 0.86±0.15 mSvy−1 and 0.58±0.11 mSvy−1 in sequence. These values were below the 1.0 mSvy−1 safety limit set for public. Although the results did not suggest any immediate exposure threat to the public, it is important that the University staffs are adequately informed of indoor radon levels and its attendant health hazards. Improved and adequate ventilation of all the office buildings is highly encouraged in order to keep the radon levels as low as reasonably achievable (ALARA).

Deoxyfluorination of phenols for chemoselective 18F-labeling of peptides.

The challenge of forming C-18F bonds is often a bottleneck in the development of new 18F-labeled tracer molecules for noninvasive functional imaging studies using positron emission tomography (PET). Nucleophilic aromatic substitution is the most widely employed reaction to functionalize aromatic substrates with the radioactive fluorine-18 but its scope is restricted to arenes containing electron-withdrawing substituents. Furthermore, many protic functional groups are incompatible with basic fluoride anions. Peptide substrates, which are highly desirable targets for PET molecular imaging, are particularly challenging to label with fluorine-18 because they are densely functionalized and sensitive to high temperatures and basic conditions. To expand the utility of nucleophilic aromatic substitution with fluorine-18, we describe two complementary procedures for the radiodeoxyfluorination of bench-stable and easy-to-access phenols that ensure rapid access to densely functionalized electron-rich and electron-poor 18F-aryl fluorides. The first procedure details the synthesis of an 18F-synthon and its subsequent ligation to the cysteine residue of Arg-Gly-Asp-Cys in 10.5 h from commercially available starting materials (189-min radiosynthesis). The second procedure describes the incorporation of commercially available CpRu(Fmoc-tyrosine)OTf into a fully protected peptide Lys-Met-Glu-(CpRu-Tyr)-Leu via solid-phase peptide synthesis and subsequent ruthenium-mediated uronium deoxyfluorination with fluorine-18 followed by deprotection, accomplished within 7 d (116-min radiosynthesis). Both radiolabeling methods are highly chemoselective and have conveniently been automated using commercially available radiosynthesis equipment so that the procedures described can be employed for the synthesis of peptide-based PET probes for in vivo imaging studies according to as low as reasonably achievable (ALARA) principles.

Development of Electrometer for Dose Area Product (DAP) Measurement to Monitor Patient Dose in Radiography Examinations

This study aimed to develop an electrometer for dose area product (DAP) measurement to monitor patient doses on X-ray radiography examinations. The electrometer was developed based on the Atmega8535 microcontroller as the processing unit. This electrometer was operated at 12 volts of direct current (DC) and controlled by buttons for navigation. The system (i.e. in-house electrometer and DAP meter) was carefully designed so that it can easily perform calibration and dose measurements. The system was evaluated at variations of tube voltage, tube current, and exposure time. The developed system results in high accuracy and precision as indicated by low percent error (PE) and relative standard deviation (RSD) compared to standard system. The highest PE and RSD are 1.69% and 1.42% for tube voltage variation, 3.85% and 3.58% for tube current variations, and 12.10% and 0.92% for exposure time variations. In conclusion, the developed system is feasible to be used as a patient dose measurement tool to meet the needs of radiation protection to achieve the principle of “as low as reasonably achievable (ALARA).

Evaluation of awareness and knowledge of CT technologist regarding diagnostic reference levels in Iran

The purpose of this study was to determine the level of knowledge and awareness regarding radiation protection and Dose Reference Levels (DRLs) among 102 Computed Tomography (CT) technologists working in various Iranian hospitals. A questionnaire including 20 multiple-choice and open-format questions was divided into demographic information, general radiation protection knowledge, and DRL knowledge. Regarding radiation protection knowledge concerning CT, about 56.9% of participants exhibited awareness of the dose display on the CT machine’s console, and about 78.4% selected the correct dosimetric units expressed CT dose. Unexpectedly, 90.2% of participants failed to define the concept of dose optimization. A significant association (p &lt; 0.05) was established between technologists’ radiation protection and DRL knowledge and a degree of education, type of hospital, and job experience. In addition, the findings reveal a correlation between radiographers’ DRL knowledge and their propensity to enroll in training courses. 26.5% of participants exhibited awareness of DRLs in CT practice, while 49% and 76.5% of participants were unable to correctly identify DRLs concept and function. To reduce patient dose in accordance with the As Low As Reasonably Achievable (ALARA) radiation protection principle, CT technologists must improve their knowledge of radiation dose and local DRLs should be defined at least at the local level.

Radiology's Ionising Radiation Paradox: Weighing the Indispensable Against the Detrimental in Medical Imaging.

Ionising radiation stands as an indispensable protagonist in the narrative of medical imaging, underpinning diagnostic evaluations and therapeutic interventions across an array of medical conditions. However, this protagonist poses a paradox - its inestimable service to medicine coexists with an undercurrent of potential health risks, primarily DNA damage and subsequent oncogenesis. The narrative of this comprehensive review unfurls around this intricate enigma, delicately balancing the indispensable diagnostic utility against the non-negotiable commitment to patient safety. In this critical discourse, the intricacies of ionising radiation are dissected, illuminating not only its sources but also the associated biological and health hazards. The exploration delves into the labyrinth of strategies currently deployed to minimise exposure and safeguard patients. By casting light on the scientific nuances of X-rays, computed tomography (CT), and nuclear medicine, it traverses the complex terrain of radiation use in radiology, to promote safer medical imaging practices, and to facilitate an ongoing dialogue about diagnostic necessity and risk. Through a rigorous examination, the pivotal relationship between radiation dose and dose response is elucidated, unravelling the mechanisms of radiation injury and distinguishing between deterministic and stochastic effects. Moreover, protection strategies are illuminated, demystifying concepts such as justification, optimisation, the As Low As Reasonably Achievable (ALARA) principle, dose and diagnostic reference levels, along with administrative and regulatory approaches. With an eye on the horizon, promising avenues of future research are discussed. These encompass low-radiation imaging techniques, long-term risk assessment in large patient cohorts, and the transformative potential of artificial intelligence in dose optimisation. This exploration of the nuanced complexities of radiation use in radiology aims to foster a collaborative impetus towards safer medical imaging practices. It underscores the need for an ongoing dialogue around diagnostic necessity and risk, thereby advocating for a continual reassessment in the narrative of medical imaging.

Reassessing lead protective garment assessment using ICRP 103 tissue weighting factors

Lead protective garments worn by medical staff in the presence of x-rays develop defects over time. This work proposes a novel method of assessing the protective efficacy of the garments as defects develop. The proposed method applies updated radiobiology data from ICRP 103. This work applied the as low as reasonably achievable principle to devise a formula through which a maximum allowed defect area in lead protective garments can be calculated. This formula depends on the cross-sectional areas () and ICRP 103 tissue weighting factors () of the most radiosensitive and overlapping organs protected by the garment, the maximum allowed additional effective dose to the garment wearer due to the defects (), and the unattenuated absorbed dose at the surface of the garment (). The maximum allowed defect areas are separated into three regions: above the waist, below the waist, and thyroid. To be conservative, it was assumed that = 50 mGy yr−1, and = 0.3 mSv yr−1. Also conservatively, transmission was assumed to be 0%, as employing a non-zero transmission factor would increase the maximum allowed defect area. Maximum allowed defect areas were as follows: 370 mm2 for above the waist, 37 mm2 for below the waist, and 279 mm2 for the thyroid. These values can be compared to commonly published values which are 670 mm2 for an apron, 15 mm2 over the gonads, and 11–20 mm2 for the thyroid. The proposed method for lead protective garment assessment is highly adaptable as values can be adjusted as radiobiology data are updated, and as values such as radiation dose limits vary across jurisdictions. Future works will include collection of data for unattenuated dose to apron () as it varies across professions, so that garments may be allowed different defect areas if relegated to individuals of specific professions.

Estimated Radiation Dose to the Lens During Endourologic Procedures: The Role of Leaded Glasses and the ALARA Protocol-An ESU/ESUT-YAU Endourology Group Collaboration.

Purpose: On February 6, 2018, the European Atomic Energy Community reduced the annual equivalent dose limit for the lens from 150 to 20 mSv/year, because of its association with cataracts at low radiation doses. Our aim was to estimate the radiation doses received by the lens during endourologic procedures that require fluoroscopy. Materials and Methods: Multicenter study including prospective data of annual eye dosimeters between 2017 and 2020. Four endourologists used an eye dosimeter in endourologic procedures that require fluoroscopy (ureteroscopy, retrograde intrarenal surgery, and percutaneous nephrolithotomy). Surgeons 1 and 2 wore leaded glasses; surgeon 1 also used the as low as reasonably achievable (ALARA) protocol. Descriptive statistical analysis using SPSS 25.0 was conducted. Results: Surgeons 1, 2, 3, and 4 performed a median of 159, 586, 102, and 129 endourologic procedures per year, respectively, for a total of 641, 2340, 413, and 350 procedures between 2017 and 2020. The median annual dose of lens radiation exposure was 0.16, 1.18, 3.79, and 1.42 mSv per year, respectively, which corresponds to 0.001, 0.009, 0.024, and 0.012 mSv per procedure. The two surgeons who used leaded glasses registered a lower radiation dose per procedure (0.001 vs 0.027). Similarly, the urologist who used the ALARA protocol registered the lowest lens radiation dose compared with the three surgeons who did not use it (0.001 vs 0.023). Conclusions: The endourologists who participated in this study effectively comply with current guidelines on radiation exposure to the lens. Registered eye lens radiation does not seem to be related to the number of procedures but rather to the use of leaded glasses and the ALARA protocol.

Does cost minimization of hypofractionated radiation therapy content all health stakeholders?

Does cost minimization of hypofractionated radiation therapy content all health stakeholders?

Methodology to compare alternative design options for radioactive waste disposal facilities under the principle of ALARA based on probabilistic approach with Bayesian inference.

In the process of optimisation of radiological protection in long-term radioactive waste management, design options for disposal facilities are assessed from the viewpoint of practical reduction in radiation dose to as low as reasonably achievable (ALARA). In this paper, a probabilistic approach is introduced to evaluate differences in dose distributions between alternative facility designs using the Bayesian inference technique. It is demonstrated by a series of parametric calculations for hypothetic disposal system designs that an additional dose from an disposal facility could be sufficiently reduced from the viewpoint of dose reduction under the ALARA principle if the design option for a disposal facility whose 95th percentile of dose distribution is lower than the target dose of 0.1mSv/y is provided. Reducing uncertainties of the distribution of dose from disposal options is also an important aspect for the practical reduction in radiation dose to which members of the public are exposed.