Let's talk about radiation dose and radiation protection in children.

Children are more sensitive to ionizing radiation than adults. Even though the risk is very low, exposure from radiological examinations can possibly cause them long-term side effects. Recent large epidemiological studies involving children and young adults have added evidence suggesting that even small doses of radiation, such as those from computed tomography scans, might slightly increase the risk of developing cancer later in life. Therefore, even though radiologic studies are essential for an accurate diagnosis and management of various conditions, it is crucial to minimize radiation exposure. This article addresses radiation protection for children in the medical use of ionizing radiation and it is set in the context of the European legislative framework regarding radiation protection. It advocates for a holistic approach to paediatric radiological tests. This approach includes the key principles of radiation protection, such as the justification of imaging procedures supported by referral guidelines, as well as the optimization of techniques (according to the ALARA principle) and effective communication with parents about the benefits and the risks of radiologic procedures. Protecting children from unnecessary radiation is not only a technical challenge, but also a moral obligation and a legal requirement.

Improvement in paediatric CT use and justification: a single-centre experience.

Objectives: To analyse changes in the use of paediatric (≤16 years) CT over the past decade and to evaluate the appropriateness of CT examinations at a tertiary teaching hospital. Methods: Data from 290 paediatric CTs were prospectively collected in 2022 and compared with data from 2017 (358 cases) and 2012 (538 cases). The justification of CTs was evaluated with regard to medical imaging referral guidelines and appropriateness rates were calculated. Results: Paediatric CTs decreased 39.4% over the 10 years, contrasting with a 27.6% increase in overall CTs. Paediatric CTs as the share of overall CTs dropped from 2.5% in 2012 to 1.1% in 2022 (P < .0001), with a concurrent rise in paediatric MRIs (P < .0001). Notable reductions in CT use occurred for head trauma (P = .0003), chronic headache (P < .0001), epilepsy (P = .037), hydrocephalus (P = .0078), chest tumour (P = .0005), and whole-body tumour (P = .0041). The overall appropriateness of CTs improved from 73.1% in 2017 to 79.0% in 2022 (P = .0049). In 15.4% of the cases, no radiological examination was deemed necessary, and in 8.7% of the cases, another modality was more appropriate. Appropriateness rates were the highest for the head and neck angiography (100%) and the chest (96%) and the lowest for the neck (66%) and the head (67%). Conclusions: Justification of CT scans can be improved by regular educational interventions, increasing MRI accessibility, and evaluating the appropriateness of the requested CT before the examination. Interventions for a more effective implementation of referral guidelines are needed. Advances in knowledge: The focus for improvement should be CTs for head and cervical spine trauma, accounting for the majority of inappropriate requests in the paediatric population.

[Evaluation of Transmitted X-ray Spectrum, Lead Equivalent, and Uniformity of Radiation Protective Clothing Made of Lead-containing and Lead-free Materials].

PURPOSE: The purpose of this study was to evaluate the protective performance of several new radiation-protective clothing and to clarify issues of quality control. METHODS: The composition of the shielding elements was analyzed using X-ray fluorescence analysis, and the energy spectrum of transmitted X-rays was measured. Furthermore, the lead equivalent and uniformity were measured from the transmitted X-ray doses according to Japanese industrial standards (JIS). Uniformity was evaluated by transmitting X-ray images of each radiation protective clothing in addition to the conventional method. RESULTS: The energy spectrum showed K-absorption edges of lead, bismuth, tin, etc., which were detected in the composition analysis. The multi-layered protective material maintained higher shielding ability at high tube voltages. In addition, X-ray images of the radiation-protective clothing showed uneven density and dots, and the differences in uniformity measurement methods and points that didn't meet the required shielding capacity were seen. CONCLUSION: The current JIS does not allow accurate evaluation of the lead equivalent and uniformity, so visual evaluation of X-ray images is important. It is necessary to establish standardized standards for quality control performed by each facility.

Evaluation of radiation protection effectivity in a cardiac angiography room using visualized scattered radiation distribution.

In this study, we devised a radiation protection tool specifically designed for healthcare professionals and students engaged in cardiac catheterization to easily monitor and evaluate scattered radiation distribution across diverse C-arm angles and arbitrary physician associated staff positions - scrub nurse, technologist positions. In this study, scattered radiation distributions in an angiography room were calculated using the Monte Carlo simulation of PHITS code. Four visualizations were performed under different C-arm angles with and without radiation protection: 1) a dose profile, 2) a 2D cross-section, 3) a 3D scattered radiation distribution, and 4) a 4D scattered radiation distribution. The simulation results detailing the scattered radiation distribution in PHITS were exported in Visualization Toolkit (vtk) format and visualized through the open-source visualization application ParaView for analysis. Visualization of the scattered dose showed that dose distribution depends on the C-arm angle and the X-ray machine output parameters (kV, mAs/second, beam filtration) which depend upon beam angulation to the patient body. When irradiating in the PA direction, the protective curtain decreased the dose by 62% at a point 80 cm from the floor, where the physician's gonads are positioned. Placing the protection board close to the X-ray tube reduced the dose by 24% at a location 160 cm from the floor, where the lens of the eye is situated. Notably, positioning the protection board adjacent to the physician resulted in a 95.4% reduction in incident air kerma. These visualization displays can be combined to understand the spread and direction of the scattered radiation distribution and to determine where and how to operate and place radiation protection devices, accounting for the different beam angulations encountered in interventional cases. This study showed that scatter visualization could be a radiation protection teaching aid for students and medical staff in angiography rooms.

Hydroxyl radical scavenging and chemical repair capabilities of positively charged peptides (PCPs): a pulse radiolysis study.

Pulse radiolysis was employed to investigate fundamental radiation chemical reactions, which are essential in the radiation protection of DNA. Two positively charged peptides (PCPs), histidine-tyrosine-histidine (His-Tyr-His) and lysine-tyrosine-lysine (Lys-Tyr-Lys), as well as the amino acids that constitute them, were involved. The reaction rate constants for tyrosine (Tyr), histidine (His), lysine (Lys), His-Tyr-His, and Lys-Tyr-Lys with OH radicals (•OH) were (1.6 ± 0.3) × 1010, (9.0 ± 0.9) × 109, (1.4 ± 0.3) × 109, (1.8 ± 0.1) × 1010, and (1.0 ± 0.1) × 1010 M-1s-1, respectively, indicating that formation of peptide bond can affect the reaction of amino acids with •OH. Observed transient absorption spectra indicated a shielding effect of the His or Lys residues at both ends of the PCPs on the centrally located Tyr. The measurement of chemical repair capabilities using deoxyguanosine monophosphate (dGMP) as a model for DNA demonstrated that the reaction rate constants of Tyr, His-Tyr-His, and Lys-Tyr-Lys with dGMP radicals were (2.2 ± 0.5) × 108, (2.3 ± 0.1) × 108, and (3.3 ± 0.4) × 108 M-1s-1, respectively, implying that the presence of a positive charge may enhance the chemical repair process.

Enhancing radiation safety awareness and practices among female radiographers: a comprehensive approach.

OBJECTIVE: This study evaluates the level of radiation safety awareness and adherence to protective practices among pregnant female radiographers in the United Arab Emirates, aiming to identify gaps and develop targeted interventions for enhancing occupational safety. METHODS: Employing a cross-sectional design, the study surveyed 133 female radiographers using a self-developed questionnaire covering demographics, awareness and knowledge, workplace practices, communication, and satisfaction. RESULTS: The survey showed high awareness among radiographers, with 97% acknowledging radiation risks during pregnancy, although 42.9% had not received formal training. Concerns over long-term health effects were significant, with 66.2% of participants worried about potential impacts. Despite these concerns, 83.5% had been informed about radiation risks and protective measures, indicating active information provision in many workplaces. However, inconsistencies in information dissemination across different work settings were noted. CONCLUSIONS: The findings highlight the need for standardized radiation safety protocols for pregnant radiographers. The variability in safety training and information dissemination suggests the importance of establishing uniform safety practices. Recommendations include developing comprehensive education and training programs for pregnant radiographers, ensuring open communication for radiation safety and pregnancy-related concerns, and enforcing clear guidelines for workplace accommodations.

The influence of apigenin on cellular responses to radiation: From protection to sensitization.

Apigenin, a dietary flavonoid, has gained increasing attention for its potential therapeutic applications in radiation protection and radiosensitization. Ionizing radiation (IR) can harm healthy cells, but as radiotherapy remains crucial in cancer treatment. Owing to the remarkable application of radiotherapy in the treatment of cancers, it is vital to protect healthy cells from radiation hazards while increasing the sensitivity of cancer cells to radiation. This article reviews the current understanding of apigenin's radioprotective and radiosensitive properties with a focuses on the involved signaling pathways and key molecular targets. When exposed to irradiation, apigenin reduces inflammation via cyclooxygenase-2 inhibition and modulates proapoptotic and antiapoptotic biomarkers. Apigenin's radical scavenging abilities and antioxidant enhancement mitigate oxidative DNA damage. It inhibits radiation-induced mammalian target of rapamycin activation, vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP), and STAT3 expression, while promoting AMPK, autophagy, and apoptosis, suggesting potential in cancer prevention. As a radiosensitizer, apigenin inhibits tumor growth by inducing apoptosis, suppressing VEGF-C, tumor necrosis factor alpha, and STAT3, reducing MMP-2/9 activity, and inhibiting cancer cell glucose uptake. Cellular and animal studies support apigenin's radioprotective and anticancer potential, making it a potential candidate for further research. Investigation into apigenin's therapeutic efficacy in diverse cancer types and radiation damage is essential.

Multicenter, international study of CT practices and radiation doses from 10 African countries: An International Atomic Energy Agency (IAEA) baseline study.

PURPOSE: The objective of our IAEA-coordinated international study was to assess CT practices and radiation doses from multiple hospitals across several African countries. METHODS: The study included 13 hospitals from Africa which contributed information on minimum of 20 consecutive patients who underwent head, chest, and/or abdomen-pelvis CT. Prior to the data recording step, all hospitals had a mandatory one-hour training on the best practices in recording the relevant data elements. The recorded data elements included patient age, weight, protocol name, scanner information, acquisition parameters, and radiation dose descriptors including phase-specific CT dose index volume (CTDIvol in mGy) and dose length product (DLP in mGy.cm). We estimated the median and interquartile range of body-region specific CTDIvol and DLP and compared data across sites and countries using the Kruskal-Wallis H Test for non-normal distribution, analysis of variance. RESULTS: A total of 1061 patients (mean age 50 ± 19 years) were included in the study. 16 % of CT exams had no stated clinical indications for CT examinations of the head (32/343, 9 %), chest (50/281, 18 %), abdomen-pelvis (67/243, 28 %), and/or chest-abdomen-pelvis CT (24/194, 12 %). Most hospitals used multiphase CT protocols for abdomen-pelvis (9/11 hospitals) and chest CT (10/12 hospitals), regardless of clinical indications. Total median DLP values for head (953 mGy.cm), chest (405 mGy.cm), and abdomen-pelvis (1195 mGy.cm) CT were above the UK, German, and American College of Radiology Diagnostic Reference Levels (DRLs). CONCLUSIONS: Concerning variations in CT practices and protocols across several hospitals in Africa were demonstrated, emphasizing the need for better protocol optimization to improve patient safety.

Radioprotective Effect of Resveratrol, Crocin, and Their Combination on Cytogenetic Alterations in Human Lymphocytes.

Background: High-dose radiation altering the genetic material in patients' bone marrow cells can lead to hematopoietic radiation syndrome. Accordingly, the presence of radiation protections agents is critical to preventing these adverse effects. Objective: This study aimed to evaluate the radioprotection of the exclusive or combination effect of resveratrol and crocin extracts at various concentrations on irradiated human lymphocytes. Material and Methods: In this experimental study, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method was used to evaluate the cell viability in pre-treatment with resveratrol, crocin, or a combination of both, using a concentration range of 5 to 4800 µM / ml in 24 h. The chromosomal aberration test was employed to determine the aberration frequency in 48 h. This study was performed on human peripheral blood lymphocytes treated with 2 Gy radiation and reliability of measurements performed by the triplicate repeat. Results: MTT results showed that the groups treated with either resveratrol or crocin at concentrations of 5 to 4800 µM had no significant reduction in cell viability. The cytogenetic analysis of irradiated lymphocytes with 2 Gy X-rays revealed a reduction in the frequency of dicentric chromosomes in all treated groups in contrast with the control group. The most significant reduction occurred in those treated with a single agent at the concentration of 100 µM and a combined drug at the concentration of 50 µM. Conclusion: The combination of resveratrol and crocin is considered a potential radioprotector and prophylactic for patients before radiation therapy.

Evaluating the Radioactive Waste Produced per Patient by Radiopharmaceutical Sources and Measuring the Radioactive Contamination of Surfaces and Staff at the Bushehr Nuclear Medicine Department.

Background: Nuclear medicine is an integral and developing field in diagnosing and treating diseases. Monitoring individuals' protection and radiation contamination in the workplace is vital for preserving working environments. Objective: This study aimed to monitor the nuclear medicine department's personnel, environment, and wastes to determine the level of occupational radiation and environmental pollution in Bushehr's nuclear medicine department. Material and Methods: In this cross-sectional study, the initial activity of each radioisotope, radiopharmaceutical, and radioactive waste was measured using a "well counter" daily for three months. Three irradiators' absorbed doses were measured using a direct reading dosimeter. The contamination was determined using an indirect wipe test method on various surfaces. A Geiger Müller dosimeter was employed to examine personnel's hands, clothing, and footwear. Results: The highest activity was observed in technetium waste (1118.31 mCi). Every irradiator received a lower absorption dose than the International Commission on Radiological Protection (ICRP) standard threshold. The majority of contamination was associated with the exercise test room (0.04 Bq/cm2) and its work surface (0.013 Bq/cm2), which were both below the threshold (0.5 Bq/cm2). Staff monitoring indicated that two nurses (10 and 11 individuals) had the highest contamination rate (23.7%). Conclusion: Daily assessment of the type, activity, and method of radiopharmaceutical administration to the patient is advantageous for waste management. Surface contamination monitoring can significantly contribute to the estimation of the level of radiation pollution in the environment.

Development of Lead-Free Materials for Radiation Shielding in Medical Settings: A Review.

Radiation protection is an essential issue in diagnostic radiology to ensure the safety of patients, healthcare professionals, and the general public. Lead has traditionally been used as a shielding material due to its high atomic number, high density, and effectiveness in attenuating radiation. However, some concerns related to the long-term health effects of toxicity, environmental disease as well as heavy weight of lead have led to the search for alternative lead-free shielding materials. Leadfree multilayered polymer composites and non-lead nano-composite shields have been suggested as effective shielding materials to replace conventional lead-based and single metal shields. Using several elements with high density and atomic number, such as bismuth, barium, gadolinium, and tungsten, offer significant enhancements in the shielding ability of composites. This review focuses on the development and use of lead-free materials for radiation shielding in medical settings. It discusses the drawbacks of traditional lead shielding, such as toxicity, weight, and recycling challenges, and highlights the benefits of lead-free alternatives.

Professor John Roderick Cameron's Influence on Radiation Safety in Terrestrial and Space Environments.

Professor John Roderick Cameron (1922-2005) stands out as a trailblazer in the field of medical physics, whose innovative work has deeply influenced radiation protection and the broader medical radiation field through sound technical judgment and insight. Best known for inventing the bone densitometry device, his pioneering efforts have reshaped modern medical practices far beyond his initial breakthroughs. Cameron's explorations extended into the realms of space biomedical science and models of terrestrial radiation, areas where his insights continue to resonate today. As the Emeritus Professor of Medical Physics at the University of Wisconsin-Madison and a founding member of the American Association of Physicists in Medicine, Cameron laid crucial groundwork for safety standards in environments with high natural radiation levels. His leadership was instrumental in advancing thermoluminescence dosimetry, radiation measurement, and image quality assurance, driving progress in both academia and clinical practices. Moreover, through establishing Medical Physics Publishing, Cameron played a pivotal role in spreading vital research and educational materials across the fields of health physics and medical physics. This commentary reflects on Cameron's far-reaching contributions, highlighting his critical work in space radiation research and terrestrial radiation models-key to the future of interplanetary travel and potential human settlement on planets like Mars. His research in areas of high background radiation, like Ramsar, Iran, has been fundamental in developing strategies for biological protection in space, which are essential for ensuring astronaut safety during long-duration space missions. We honor Professor Cameron's profound legacy, celebrating his visionary spirit and the lasting impact of his contributions on generations of scientists in radiation science.

Low-dose, standard, and high-resolution cone beam computed tomography for alveolar bone measurements related to implant planning: An ex vivo study in human specimens.

AIM: To evaluate the performance of low-dose cone beam computed tomography (CBCT) protocols with regard to linear bone measurements in the posterior mandible for implant planning compared with higher dose protocols. MATERIALS AND METHODS: Forty-two edentulous posterior sites in human cadaveric mandibles were imaged in three CBCT scanners using three or four protocols with varying exposure parameters to achieve lower dose. Co-registration was performed to generate sagittal and cross-sectional image sections representative of the implant site. Three observers measured bone height, from the alveolar crest to the mandibular canal, and width, three mm from the top of the alveolar crest. Intra- and interobserver reproducibility were assessed for the cases rated as nonmeasurable as well as for completed measurements. The measurements were analyzed using paired t-tests for differences among the CBCT protocols and the frequency distribution of nonmeasurable cases with a Pearson Chi-square test. RESULTS: Reproducibility for registering nonmeasurable cases varied among observers; however, no consistent significant differences were found in the frequency distribution of these cases among observers, units, and protocols. Intraclass correlation coefficients (ICC) were >0.9 for all measurements of bone height and width. Mean differences of <0.5 mm were found regardless of protocol; however, one observer did in some cases produce larger differences. CONCLUSION: Linear bone measurements did not differ significantly and could be performed with excellent reliability, using low-dose CBCT protocols compared with standard and high-resolution ones. Varying approaches for rating nonmeasurable cases were found, indicating differences in diagnostic strategies related to implant planning among observers.

X-ray spectrometry for calculating conversion coefficients from air kerma to operational quantities in radiation protection.

This study explores the conversion coefficients from air kerma to operational quantities for radiation protection, using x-ray spectrometry for the narrow-beam qualities below 300 keV as defined by ISO 4037-1. By employing custom spectral correction algorithms combined with modern cadmium telluride (CdTe) semiconductor detectors, we effectively corrected spectral distortions caused by detection processes, ensuring more reliable measurements. These measurements are crucial for meeting radiation protection standards. The study also analyses the sources of uncertainty associated with the determination of conversion coefficients, thereby providing improved accuracy and reproducibility in photon dosimetry.

Amifostine loaded lipid-calcium carbonate nanoparticles as an oral drug delivery system for radiation protection.

Amifostine (AMF) as the first-line radiation protection drug, usually suffered from low compliance and short half-life upon clinical applications. The development of oral drug delivery system (DDS) for AMF is a promising solution. However, the inherent shortages of AMF present significant challenges in the design of suitable oral DDS. Here in this study, we utilized the ability of calcium ions to bind with AMF and prepared AMF loaded calcium carbonate (CC) core, CC/AMF, using phase transferred coprecipitation method. We further modified the CC/AMF using phospholipids to prepare AMF loaded lipid-calcium carbonate (LCC) hybrid nanoparticles (LCC/AMF) via a thin-film dispersion method. LCC/AMF combines the oral advantages of lipid nanoparticles with the drug-loading capabilities of CC, which was shown as uniform nano-sized formulation with decent stability in aqueous solution. With favorable intestinal transport and absorption effects, it effectively enhances the in vivo radiation protection efficacy of AMF through oral administration. More importantly, we further investigated the cellular accumulation profile and intracellular transport mechanism of LCC/AMF using MDCK and Caco-2 cell lines as models. This research not only alters the current administration method of AMF to enhance its convenience and compliance, but also provides insights and guidance for the development of more suitable oral DDS for AMF in the future.

Update on radiation protection of the thyroid gland.

In recent years, concern about the effects of ionizing radiation on exposed individuals has led to the need to regulate and quantify the use of diagnostic and therapeutic techniques. Geopolitical events in recent times have also increased the population's perception of insecurity regarding ionizing radiation, and we increasingly face patients reluctant to undergo certain types of scans in our nuclear medicine services and, albeit less frequently, in radiology services. This article aims to summarise the extent to which ionizing radiation is present in our daily lives and how diagnostic and therapeutic procedures can affect our health, particularly from the perspective of their effects on the thyroid gland, one of the body's most radiation-sensitive organs.

Actinium-225 as an example for monitoring of internal exposure of occupational intakes of radionuclides in face of new nuclear-medical applications for short-lived alpha emitting particles.

Monitoring of internal exposure to short-lived alpha-emitting radionuclides such as actinium-225 (225Ac), which are becoming increasingly important in nuclear medicine, plays an important role in the radiation protection of occupationally exposed persons. After having tested gamma spectrometry, liquid scintillation counting and alpha spectrometry for monitoring of internal exposure, the focus of the present study was on solid phase extraction of 225Ac from urine in combination with alpha spectrometry. The development of the method was based on recent findings from the literature on this topic. The method was used in a pilot phase to monitor internal exposure of four workers who were directly or indirectly involved in the manufacture and/or use of 225Ac. The monitoring protocol allowed a relatively short 24-hour urine sample analysis with excellent recovery of the internal standard, but it did not allow for a detection limit of less than 1 mBq nor a sufficient yield of 225Ac. Based on these results it is concluded that an in vitro excretion analysis alone is not appropriate for monitoring internal exposure to 225Ac. Instead, different radiation monitoring techniques have to be combined to ensure the radiation protection of employees.

Quantitative stakeholder-driven assessment of radiation protection issues via a PIANOFORTE online survey.

To enhance stakeholder engagement and foster the inclusion of interests of citizens in radiation protection research, a comprehensive online survey was developed within the framework of the European Partnership PIANOFORTE. This survey was performed in 2022 and presented an opportunity for a wide range of stakeholders to voice their opinions on research priorities in radiation protection for the foreseeable future. Simultaneously, it delved into pertinent issues surrounding general radiation protection. The PIANOFORTE e-survey was conducted in the English language, accommodating a diverse range of participants. Overall, 440 respondents provided their insights and feedback, representing a broad geographical reach encompassing 29 European countries, as well as Canada, China, Colombia, India, and the United States. To assess the outcomes, the Positive Matrix Factorization numerical model was applied, in addition to qualitative and quantitative assessment of individual responses, enabling the discernment of four distinct stakeholder groups with varying attitudes. While the questionnaire may not fully represent all stakeholders due to the limited respondent pool, it is noteworthy that approximately 70% of the participants were newcomers to comparable surveys, demonstrating a proactive attitude, a strong willingness to collaborate and the necessity to continuously engage with stakeholder groups. Among the individual respondents, distinct opinions emerged particularly regarding health effects of radiation exposure, medical use of radiation, radiation protection of workers and the public, as well as emergency and recovery preparedness and response. In cluster analysis, none of the identified groups had clear preferences concerning the prioritization of future radiation protection research topics.