Health Physics Research Articles

Validation and Efficiency Evaluation of Automated Quality Assurance Software SunCHECK™ Machine for Mechanical and Dosimetric Quality Assurance.

Recent decades have witnessed transformative advances in radiation physics and computer technology, revolutionizing the precision of radiation therapy. The adoption of intricate treatment techniques such as three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, volumetric-modulated arc therapy, and image-guided radiotherapy necessitates robust quality assurance (QA) programs. This study introduces the SunCHECK™ Machine (SCM), a web-based QA platform, presenting early results from its integration into a comprehensive QA program. linear accelerators (LINAC) demand QA programs to uphold machine characteristics within accepted tolerances. The increasing treatment complexity underscores the need for streamlined procedures. The selection of QA tools is vital, requiring efficiency, accuracy, and alignment with clinic needs, as per recommendations such as the AAPM task group 142 report. The materials and methods section details SCM implementation in various QA aspects, encompassing daily QA (DQA), imaging QA with Catphan, conventional output assessment with a water phantom, and LINAC isocenter verification through the Winston-Lutz test. Challenges in QA processes, such as manual data transcription and limited device integration, are highlighted. Early results demonstrate SCM's significant reduction in QA time, ensuring accuracy and efficiency. Its automation eliminates interobserver variation and human errors, contributing to time savings and near-immediate result publication. SCM's role in consolidating and storing DQA data within a single platform is emphasized, offering potential in resource optimization, especially in resource-limited settings. In conclusion, SCM shows promise for efficient and accurate mechanical and dosimetric QA in radiation therapy. The study underscores SCM's potential to address contemporary QA challenges, contributing to improved resource utilization without compromising quality and safety standards.

The convergence approach may be critical to improving early situational awareness in hostile radioactive environments

This study explores the impact of a simulated radiological dispersal device (RDD) event in an urban area on young adults around 20 years old. The RDD releases radioactive Cs-137 (7.0E+3 Ci), a common industrial sterilization source. The study aims to demonstrate that combining computational codes and epidemiological models can produce valuable data to guide initial actions when confronting a hostile radioactive environment. The HotSpot Health Physics and RESRAD-RDD codes were used in the simulation to evaluate the event's initial phase. The codes were executed together, and the HotSpot output data was input into RESRAD-RDD. Based on simulated radiation dose levels, estimated doses were incorporated into radioepidemiological models proposed by the Committee on Biological Effects of Ionizing Radiation (BEIR V or VII report). Despite limitations, data transfer between the models revealed no discontinuities or antagonisms. Radiation doses were simulated under three exposure conditions and two atmospheric release modes (day or night), suggesting that atmospheric conditions, sex, and exposure routine can strongly influence the perception of radiation impacts. This combination of methods can increase situational awareness and help with decision-making and developing coping strategies.

Comparing the output of measured and GEANT4 simulated X-ray tubes

Monte Carlo simulation codes that model particle interactions with matter, including GEANT4, can be used to support the development of novel X-ray tubes and instruments for applications in industry and research. Based on our knowledge, simulations of the output of transmission-geometry X-ray tubes have not yet been conducted in GEANT4. Simulations of reflection-geometry tubes are scarce, with a limited number of studies investigating the capability and accuracy of GEANT4 in this domain. Therefore, the aim of this work is to benchmark GEANT4 for the characterisation of X-ray tubes with industry applications, using for the first time a range of X-ray tubes geometries and high voltages. In this work, GEANT4 is benchmarked against experimental measurements performed at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia, with both transmission and reflection X-ray tubes. High voltages between 17 kV and 42.5 kV for tungsten, molybdenum, gold, and silver targets are investigated. The measurements have been performed with a MXR packaged X-ray tube (reflection) and Magnum X-ray tubes (transmission) and a fast silicon drift detector (SDD). Our study shows that GEANT4 predicts the bremsstrahlung continuum output of transmission and reflection X-ray tubes, in agreement with the experimental measurements. The Penelope physics models, distributed with GEANT4, and the GEANT4 X-ray fluorescence data libraries ANSTO HF, based on the Hartree-Fock approach, exhibit the best agreement against experimental measurements. Depending on the high voltage, target and X-ray line agreement was found to vary between 10% and 300%. Differences between GEANT4 and experimental data are more significant for lower voltage X-ray tube measurements and are most likely due to limitations in the ionisation electron cross-section and/or atomic relaxation data libraries used. As next steps, it is recommended to validate GEANT4 against other, independent experimental measurements to corroborate the results of this work. In addition, it would be useful to repeat the same study with other general purpose Monte Carlo codes for radiation physics to compare their capability against GEANT4 in this application domain.

Evaluation of a Digital Mammography System with the MAM-162 phantom

Quality controls are performed to verify the performance status of X-ray equipment in relation to image quality and patient dose. Originally, the Laboratory of Radiation Physics and Metrology (LAF-RAM) in Nicaragua had only one phantom to evaluate mammography image quality subjectively; however, under a cooperation project with the International Atomic Energy Agency (IAEA), the MAM-162 phantom was acquired for the evaluation of physical image quality. In this work a CR type digital mammography system was evaluated using the MAM-162 phantom with adaptation to a single quality control protocol based on international standards such as the German Institute for Standardization (DIN) DIN 6868-162:2013-06, the IAEA technical document TECDOC protocol No. 1958 and the European Federation of Organizations for Medical Physics (EFOMP) mammo protocol. Among the main tests performed are the evaluation of the lateral image limit of the chest wall with satisfactory results, the automatic exposure control, the Signal-to-Noise difference ratio that complies with the tolerances, in the case Ghosting and dynamic range the results of both are satisfactory, the presence of artifacts was observed when applying variance mapping, a base value of the dynamic range was also obtained. For the dosimetry, the half value layer and the determination of the Mean Glandular Dose were evaluated, which does not comply with the tolerances. The final protocol document could be validated and implemented as part of the management and service documents of the Quality Control and Monitoring Laboratory (LCM) of LAF-RAM.

Risk Assessment for Workers with Wearable Medical Devices Exposed to Electromagnetic Fields.

The exponential diffusion of wearable medical devices (WMD) in recent years has involved people of all ages, including workers. Workers who use WMDs should be considered at a particular risk from electromagnetic fields, and in accordance with EU Directive 2013/35/EU, they require an individual risk assessment. Currently, there is no international standard that provides specific guidance on how to perform such a risk assessment. This paper focuses on the effects of electromagnetic fields on WMDs and does not consider the direct effects on human body tissues. It aims to offer practical recommendations to employers and/or health physicists for the risk assessment of workers with WMDs. Focusing on EU countries, we first describe the requirements outlined by the technical standard for the electromagnetic compatibility (EMC) of medical electrical equipment EN 60601-1-2. Then, some general guidelines on how to perform the risk assessment are provided. The assessment can be conducted by comparing the field values measured in the workplace with the immunity test levels specified in the technical standards of medical electrical equipment. If the measured values are lower than the immunity test levels indicated in the standard and the distance from the electromagnetic source is greater than the distance used by the manufacturer during the EMC (electromagnetic compatibility) tests (typically 30 cm), the risk for the worker may be considered acceptable. However, if the measured values exceed the immunity test levels or the distance criteria, a specific evaluation based on a case-by-case analysis is required.

Health Physics Aspects Associated with Magnetic Confinement Fusion Power Facilities

Bevelacqua Resources, 7531 Flint Crossing Circle SE, Owens Cross Roads, AL 35763 USA bevelresou@aol.com Health physics aspects associated with magnetic confinement fusion are addressed. These aspects are investigated within the context of the operation of the International Thermonuclear Experimental Reactor currently called ITER. ITER has health physics elements in common with existing fission facilities as well as unique fusion related features. Fusion facility neutron radiation is similar to that encountered in a low energy accelerator. The tritium hazard has radiation protection issues in common with the Canadian Deuterium reactor. Completion of the final ITER design, its performance characteristics, component lifetimes, and maintenance requirements will determine the actual health physics hazards. Numerous open issues are required to complete the design of ITER and resolution of these issues will affect the design as well as the health physics implications for occupationally exposed workers. Key Words: Fusion Power Facility, ITER, Magnetic Confinement, Radiological Characteristics

The concept of «Complexity» in the problems of condensed matter physics: fundamental and applied aspects

Problems of radiation effects of living and inanimate objects are considered within the framework of the concept of complexity. Basic models for the manifestation of the effects of spin chemistry and quantum entanglement in the processes of subthreshold radiation physics have been constructed

Radiation Oncology Workforce: Supply and Demand

Since 2017, the specialty of radiation oncology has experienced its fifth consecutive year of decline in residency applicants, resulting in a high number of unmatched positions. The cause of this precipitous decline is multifactorial. Factors cited include concerns about future job opportunities, the decreased pass rate in the ABR radiation biology and physics boards examinations in 2018, and the continued lack of formal exposure to radiation oncology during medical school training. We summarize the issues facing the field of radiation oncology and discuss how we could learn from similar experiences in diagnostic radiology and other specialties to address these concerns. We propose potential solutions to ensure an adequate and diverse number of residency applicants to serve the future workforce needs in radiation oncology.

Artificial intelligence model GPT4 narrowly fails simulated radiological protection exam

This study assesses the efficacy of Generative Pre-Trained Transformers (GPT) published by OpenAI in the specialised domains of radiological protection and health physics. Utilising a set of 1064 surrogate questions designed to mimic a health physics certification exam, we evaluated the models’ ability to accurately respond to questions across five knowledge domains. Our results indicated that neither model met the 67% passing threshold, with GPT-3.5 achieving a 45.3% weighted average and GPT-4 attaining 61.7%. Despite GPT-4’s significant parameter increase and multimodal capabilities, it demonstrated superior performance in all categories yet still fell short of a passing score. The study’s methodology involved a simple, standardised prompting strategy without employing prompt engineering or in-context learning, which are known to potentially enhance performance. The analysis revealed that GPT-3.5 formatted answers more correctly, despite GPT-4’s higher overall accuracy. The findings suggest that while GPT-3.5 and GPT-4 show promise in handling domain-specific content, their application in the field of radiological protection should be approached with caution, emphasising the need for human oversight and verification.

Gamma-ray Spectroscopy in Low-Power Nuclear Research Reactors

Gamma-ray spectroscopy is an effective technique for radioactive material characterization, routine inventory verification, nuclear safeguards, health physics, and source search scenarios. Gamma-ray spectrometers typically cannot be operated in the immediate vicinity of nuclear reactors due to their high flux fields and their resulting inability to resolve individual pulses. Low-power reactor facilities offer the possibility to study reactor gamma-ray fields, a domain of experiments hitherto poorly explored. In this work, we present gamma-ray spectroscopy experiments performed with various detectors in two reactors: The EPFL zero-power research reactor CROCUS, and the neutron beam facility at the Ohio State University Research Reactor (OSURR). We employed inorganic scintillators (CeBr3), organic scintillators (trans-stilbene and organic glass), and high-purity germanium semiconductors (HPGe) to cover a range of typical—and new—instruments used in gamma-ray spectroscopy. The aim of this study is to provide a guideline for reactor users regarding detector performance, observed responses, and therefore available information in the reactor photon fields up to 2 MeV. The results indicate several future prospects, such as the online (at criticality) monitoring of fission products (like Xe, I, and La), dual-particle sensitive experiments, and code validation opportunities.

A systematic review of immersive educational technologies in medical physics and radiation physics.

This systematic review aims to analyze and synthesize the current state of research on the role of immersive technologies, specifically augmented reality (AR), virtual reality (VR), and mixed reality (MR), in medical physics and radiation physics education. The primary focus is to evaluate their impact on learning outcomes, performance, and engagement across various educational contexts. We conduct a comprehensive search of four major databases: Scopus, Web of Science, PubMed, and IEEE Xplore, covering the period from 2012 to 2023. A total of 316 articles are initially identified. After removing duplicates and screening for relevance based on titles and abstracts, 107 articles are selected for full-text review. Finally, 37 articles met the inclusion criteria and are included in the analysis. The review follows the PRISMA guidelines and utilizes the PICOS framework to structure the research question. Data extraction focuses on key variables such as the type of immersive technology used, educational context, study design, participant demographics, and measured outcomes. The studies are analyzed for their reported effects on learning outcomes, performance, and engagement. The review found that immersive technologies significantly enhance learning outcomes and engagement. Specifically, 36.4% of the studies reported increased engagement, while 63.6% of studies focusing on practical skills noted performance improvements. The use of AR, VR, and MR showed broad applicability across different educational levels, from undergraduate courses to professional training programs. Immersive technologies have considerable potential to transform medical and radiation physics. They enhance student engagement, improve learning outcomes, and boost performance in practical skills. Nevertheless, future research should focus on standardizing methodologies, expanding participant demographics, and exploring long-term impacts on skill retention and clinical practice. This review provides a valuable resource for guiding future research and implementing innovative educational strategies in the dynamic fields of medical physics and radiation physics.

Magnetar Central Engine Powering the Energetic GRB 210610B?

The bright GRB 210610B was discovered simultaneously by Fermi and Swift missions at redshift 1.13. We utilized broadband Fermi-GBM observations to perform a detailed prompt emission spectral analysis and to understand the radiation physics of the burst. Our analysis displayed that the low energy spectral index (αpt) exceeds boundaries expected from the typical synchrotron emission spectrum (-1.5,-0.67), suggesting additional emission signature. We added an additional thermal model with the typical Band or CPL function and found that CPL + BB function is better fitting to the data, suggesting a hybrid jet composition for the burst. Further, we found that the beaming corrected energy (Eγ,θj = 1.06 × 1051 erg) of the burst is less than the total energy budget of the magnetar. Additionally, the X-ray afterglow light curve of this burst exhibits achromatic plateaus, adding another layer of complexity to the explosion’s behavior. Interestingly, we noted that the X-ray energy release during the plateau phase (EX,iso = 1.94 × 1051 erg) is also less than the total energy budget of the magnetar. Our results indicate the possibility that a magnetar could be the central engine for this burst.

Open Letter to the Health Physics Society Membership.

Open Letter to the Health Physics Society Membership.

Short-term urban resilience estimation after a hypothetical nuclear event

<abstract> <p>In the event of a hypothetical tactical nuclear device being detonated in a densely populated urban area, the first responders must be well-prepared to make immediate decisions with limited information. To aid in this preparation, a computer simulation using the HotSpot Health Physics code was conducted to model the detonation of a tactical nuclear device in an international airport and its surroundings, considering different yields ranging from 1 to 10 kilotons. The simulation was conservative and applied to a time window of 4 days in the initial phase of the response to the event. The simulation findings allow for assessing the immediate effects of the electromagnetic pulse (EMP) and the radioactive contamination plumes on an inhabited area. This assessment includes data on the size of impacted zones, compromise of critical local infrastructure, radiological risk to potentially affected populations, and estimation of urban resilience and its temporal dynamics. This information helps raise levels of protection and optimize available resources.</p> </abstract>

Glossary of Terms and Concepts in Medical Radiation Physics. Terminology Used in Dosimetry and Treatment Planning of Brachytherapy

Medical radiation physics supports medical diagnostic and treatment process based on the use of ionizing radiation in radiation therapy, nuclear medicine, radiation diagnostics and radiation safety of patients and personnel. However, the successful implementation of this process requires close interaction of specialists in all the above areas. The basis of such interaction is the unification of the terminology and concepts used at various stages of the diagnostic and treatment process. The article presents a glossary on dosimetry and treatment planning of brachytherapy which contains the most commonly used terms in this field and explanations for each of them. The glossary is intended for use both in professional education, including postgraduate education, and for medical physicists and radiation oncologists working in radiological medical organizations

Glossary of Terms and Concepts in Medical Radiation Physics. Terminology Used in Quality Assurance of External Radiation Therapy

Medical radiation physics supports medical diagnostic and treatment process based on the use of ionizing radiation in radiation therapy, nuclear medicine, radiation diagnostics and radiation safety of patients and personnel. However, the successful implementation of this process requires close interaction of specialists in all the above areas. The basis of such interaction is the unification of the terminology and concepts used at various stages of the diagnostic and treatment process. The article presents a glossary on quality assurance of external radiation therapy which contains the most commonly used terms in this field and explanations for each of them. The glossary is intended for use both in professional education, including postgraduate education, and for medical physicists and radiation oncologists working in radiological medical organizations.

Kinetic simulations and gamma-ray signatures of Klein–Nishina relativistic magnetic reconnection

ABSTRACT Black hole and neutron star environments often comprise collisionless plasmas immersed in strong magnetic fields and intense baths of low-frequency radiation. In such conditions, relativistic magnetic reconnection can tap the magnetic field energy, accelerating high-energy particles that rapidly cool by inverse Compton (IC) scattering the dense photon background. At the highest particle energies reached in bright gamma-ray sources, IC scattering can stray into the Klein–Nishina regime. Here, the Comptonized photons exceed pair-production threshold with the radiation background and may thus return their energy to the reconnecting plasma as fresh electron–positron pairs. To reliably characterize observable signatures of such Klein–Nishina reconnection, in this work, we present first-principles particle-in-cell simulations of pair-plasma relativistic reconnection coupled to Klein–Nishina and pair-production physics. The simulations show substantial differences between the observable signatures of Klein–Nishina reconnection and reconnection coupled only to low-energy Thomson IC cooling (without pair production). The latter regime exhibits strong harder-when-brighter behaviour; the former involves a stable spectral shape independent of overall brightness. This spectral stability is reminiscent of flat-spectrum radio quasar (FSRQ) GeV high states, furnishing evidence that Klein–Nishina radiative physics operates in FSRQs. The simulated Klein–Nishina reconnection pair yield spans from low to order-unity and follows an exponential scaling law in a single governing parameter. Pushing this parameter beyond its range studied here might give way to a copious pair-creation regime. Besides FSRQs, we discuss potential applications to accreting black hole X-ray binaries, the M87* magnetosphere, and gamma-ray binaries.

New Insight into the Effects of Gaseous CO2 on Spherically Symmetric Droplet Flames

This study investigated the effect of CO2 on the burning behavior and radiative properties of a single ethanol droplet flame in microgravity. Measurements of the droplet burning rate, the flame size and temperature, and the radiative emissions were performed, under microgravity conditions for ethanol droplets burning in N2 and CO2 environments, using the 1.5 s drop tower facilities at the Korea Maritime and Ocean University (KMOU). The non-monotonic sooting behaviors (caused by the elevated O2 concentrations) were found to have a significant influence on radiative heat losses in N2 environments, resulting in non-linear droplet burning behaviors with O2 concentrations. Due to the unique nature of CO2 in microgravity, which absorbs radiative energy from the flame and raises the temperatures of the surrounding gases, the CO2 environments suppressed the radiative heat losses from the flame, regardless of the non-monotonic sooting behavior observed at the higher O2 concentrations. These experimental findings highlight the complicated physics of CO2 gas radiation in microgravity, which has not been quantitatively explored.

Preface

It is a matter of great pleasure for the organizers to bring out the Conference proceedings of the 6th National Conference on Advanced Materials and Radiation Physics (AMRP-2023) in Journal of Physics: Conference Series. The 6th National Conference on Advanced Materials and Radiation Physics (AMRP-2023) was held during May 18-19, 2023 through HYBRID Mode at Sant Longowal Institute of Engineering and Technology, Longowal, Punjab (INDIA). The AMRP-2023 conference is an important event that brings academics and researchers from all over India to share their professional experiences, expand their professional knowledge and receive updates on the latest advances in the field of advanced materials and radiation Physics.Materials science is an interdisciplinary field which deals with the discovery and design of new materials involving the study of materials through the materials paradigm (synthesis, structure, properties and performance). The subject covers a broad spectrum of materials science research including functional materials, synthesis and processing, theoretical analyses, characterization and properties of materials. Emphasis is also placed on the interdisciplinary nature of materials science and issues at the forefront of the field, such as energy and environmental issues, as well as medical and bioengineering applications are also discussed.The Radiation Physics is highly multidisciplinary in nature and is now the backbone of the nuclear medical diagnostics. The radiation physics research covers many areas of radiation imaging techniques, fundamental studies of semiconductor radiation detectors, detector materials, radiation interaction with matter and medical physics which aims to improve knowledge and methods in the field of radiation physics and radiation dosimetry, in order to develop new radiation measurement instruments and methods for applications in research, industry and medicine.In this conference more than 150 researchers from reputed universities/institutes have shown interest in hybrid mode participation. The conference included one key note address, four plenary talks, six invited talks, and presentation of more than 130 contributed papers via online & offline mode on different aspects of the conference theme. We extend our sincere gratitude to all the authors who submitted their papers to the AMRP conference. We also like to express our great appreciation to the Keynote, plenary and invited speakers.We are thankful to Institute administration for extending all support and motivation to organize this conference. On behalf of the Conference Organizing Committee, we would like to thank the referees for their efficient and thoughtful actions. We are grateful to the members of the Organising Committee for their efforts in making and shaping the program for AMRP 2023. Particularly, we acknowledge the publishing support from the members of Journal of Physics: Conference Series. We hope that the future AMRP will be as successful and stimulating, as indicated with the contributions presented in this volume.Organising Committee AMRP-2023List of Organising Committee is available in this Pdf.

2023 MILITARY HEALTH PHYSICS SECTION CIVILIAN SUPERIOR SERVICE AWARD: Presented to JULIE A. CLEMENTS by the Health Physics Society July 2023.

2023 MILITARY HEALTH PHYSICS SECTION CIVILIAN SUPERIOR SERVICE AWARD: Presented to JULIE A. CLEMENTS by the Health Physics Society July 2023.