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Medical Physics Aug 2022Proton imaging makes use of high-energy, low-intensity proton beams that fully traverse the patient and has been suggested to reduce range uncertainty in proton therapy....
BACKGROUND
Proton imaging makes use of high-energy, low-intensity proton beams that fully traverse the patient and has been suggested to reduce range uncertainty in proton therapy. Upright patient positioning with proton imaging is being considered for a fixed beam room of a new proton therapy facility currently under construction. Considering that the yield and energy spectrum of secondary radiation from high-energy proton beams is proton beam energy dependent, an assessment of radiation shielding at the energies required for proton imaging should be performed prior to use. Furthermore, NCRP 144 recommends that pion production be considered for proton energies greater than 300 MeV, which are not typically utilized for proton therapy but may be required for proton imaging.
PURPOSE
The purpose of this work was to determine whether proton treatment and imaging with an upright patient positioning system on a fixed beamline were acceptable from a radiation shielding perspective. This is the first report on radiation shielding assessment of proton imaging applications and includes consideration of pion production at the proton beam energy of 330 MeV.
METHODS
The Geant4 Monte Carlo toolkit was used for the radiation shielding assessment. The calculations consisted of the generation of secondary particle phase-space files by simulating the passage of high-energy proton beams in two target materials, and subsequent simulation of the secondary particles in the proton therapy facility geometry. Particle fluence was converted to operational and protection radiation safety quantities with a custom python script for assessment of instantaneous and annual doses, respectively.
RESULTS
The total yields of pions from a 330-MeV proton beam were many orders of magnitude less than that of neutrons and photons. Three-dimensional maps of ambient dose rate for a 330-MeV proton beam showed doses arising from secondary neutrons and photons far exceed those arising from pion production. Incorporating representative annual workloads into the calculation demonstrated that proton imaging doses outside the shielded area were negligible compared to those arising from proton therapy.
CONCLUSIONS
Pion production has a negligible impact on the radiation shielding of proton imaging at 330 MeV relative to neutron and photon production. Radiation shielding designed for proton therapy is adequate for high-energy proton imaging applications.
Topics: Humans; Monte Carlo Method; Neutrons; Proton Therapy; Protons; Radiation Dosage; Radiation Protection; Radiometry
PubMed: 35611603
DOI: 10.1002/mp.15727 -
Journal of the American College of... Feb 2023US physicians in multiple specialties who order or conduct radiological procedures lack formal radiation science education and thus sometimes order procedures of limited... (Review)
Review
US physicians in multiple specialties who order or conduct radiological procedures lack formal radiation science education and thus sometimes order procedures of limited benefit or fail to order what is necessary. To this end, a multidisciplinary expert group proposed an introductory broad-based radiation science educational program for US medical schools. Suggested preclinical elements of the curriculum include foundational education on ionizing and nonionizing radiation (eg, definitions, dose metrics, and risk measures) and short- and long-term radiation-related health effects as well as introduction to radiology, radiation therapy, and radiation protection concepts. Recommended clinical elements of the curriculum would impart knowledge and practical experience in radiology, fluoroscopically guided procedures, nuclear medicine, radiation oncology, and identification of patient subgroups requiring special considerations when selecting specific ionizing or nonionizing diagnostic or therapeutic radiation procedures. Critical components of the clinical program would also include educational material and direct experience with patient-centered communication on benefits of, risks of, and shared decision making about ionizing and nonionizing radiation procedures and on health effects and safety requirements for environmental and occupational exposure to ionizing and nonionizing radiation. Overarching is the introduction to evidence-based guidelines for procedures that maximize clinical benefit while limiting unnecessary risk. The content would be further developed, directed, and integrated within the curriculum by local faculties and would address multiple standard elements of the Liaison Committee on Medical Education and Core Entrustable Professional Activities for Entering Residency of the Association of American Medical Colleges.
Topics: Humans; Schools, Medical; Multimedia; Radiology; Curriculum; Radiation Protection
PubMed: 36130692
DOI: 10.1016/j.jacr.2022.08.010 -
Igaku Butsuri : Nihon Igaku Butsuri... 2022Boron neutron capture therapy (BNCT) is a radiation therapy that uses charged particles produced by a nuclear reaction between thermal neutrons and B. A high-intensity...
Boron neutron capture therapy (BNCT) is a radiation therapy that uses charged particles produced by a nuclear reaction between thermal neutrons and B. A high-intensity neutron source is required to perform BNCT, and it is important to understand the behavior of neutrons. Since BNCT using accelerators has been approved as a medical device, the number of treatment facilities is expected to increase in the future. This article describes the basic knowledge required to understand BNCT in clinical practice, including neutron generation and material interactions, as well as radiation protection considerations specific to BNCT.
Topics: Boron Neutron Capture Therapy; Neutrons; Radiation Protection
PubMed: 36184424
DOI: 10.11323/jjmp.42.3_143 -
Journal of Radiological Protection :... Mar 2018The use of radiological activity in the operating room (OR) and a regulatory decrease of the eye lens dose warrant an assessment of how medical staff are protected from...
The use of radiological activity in the operating room (OR) and a regulatory decrease of the eye lens dose warrant an assessment of how medical staff are protected from radiation. This study aims to evaluate practices and knowledge in radiation protection (RP) for OR doctors before and after training. A descriptive study of surgeons and anesthetists in a French public hospital center was conducted in 2016. An ad hoc questionnaire concerning occupational practices and knowledge about RP was distributed before and one month after RP training. Among 103 doctors attending the training, 90 answered the questionnaire before the training. Results showed a lack of knowledge and good practice in RP. Most of the participants (86.7%) had never been trained in RP and recognized insufficient knowledge. Most of them (92.2%) wore a lead apron, 50.0% a thyroid-shield, 5.6% lead glasses, 53.3% a passive dosimeter and 17.8% an electronic dosimeter. None of them benefitted from collective protective equipment such as a ceiling suspended screen. The questionnaire following the training was completed by only 35 doctors. A comparison before and after training results showed an improvement in knowledge (scores of correct responses: 5.5/16 before and 9.5/16 after training) but not in RP good practices (scores of correct responses: 3.2/7 before and 3.3/7 after training). One training session appears to be insufficient to improve the application of the safety rules when x-rays are used. Communication needs to be improved regarding RP among anesthetists and surgeons, such as training renewal, workstation analysis in OR related to x-ray use and occupational medical follow-up. Otherwise, radiological risks in OR need to be given better consideration, such as radio-induced cataract risk. It is necessary to encourage the use of dosimeters and protective equipment and to strengthen access to lead glasses and collective protective equipment, such as ceiling suspended screens. All these recommendations ensure the received dose is reduced to as low as is reasonably achievable.
Topics: Adult; Anesthetists; Female; Health Knowledge, Attitudes, Practice; Humans; Male; Middle Aged; Operating Rooms; Radiation Dosage; Radiation Dosimeters; Radiation Protection; Surgeons; Surveys and Questionnaires
PubMed: 29182150
DOI: 10.1088/1361-6498/aa9dbd -
Journal of Environmental Radioactivity Jul 2016This paper reports the output of a consensus symposium organized by the International Union of Radioecology in November 2015. The symposium gathered an academically...
Addressing ecological effects of radiation on populations and ecosystems to improve protection of the environment against radiation: Agreed statements from a Consensus Symposium.
This paper reports the output of a consensus symposium organized by the International Union of Radioecology in November 2015. The symposium gathered an academically diverse group of 30 scientists to consider the still debated ecological impact of radiation on populations and ecosystems. Stimulated by the Chernobyl and Fukushima disasters' accidental contamination of the environment, there is increasing interest in developing environmental radiation protection frameworks. Scientific research conducted in a variety of laboratory and field settings has improved our knowledge of the effects of ionizing radiation on the environment. However, the results from such studies sometimes appear contradictory and there is disagreement about the implications for risk assessment. The Symposium discussions therefore focused on issues that might lead to different interpretations of the results, such as laboratory versus field approaches, organism versus population and ecosystemic inference strategies, dose estimation approaches and their significance under chronic exposure conditions. The participating scientists, from across the spectrum of disciplines and research areas, extending also beyond the traditional radioecology community, successfully developed a constructive spirit directed at understanding discrepancies. From the discussions, the group has derived seven consensus statements related to environmental protection against radiation, which are supplemented with some recommendations. Each of these statements is contextualized and discussed in view of contributing to the orientation and integration of future research, the results of which should yield better consensus on the ecological impact of radiation and consolidate suitable approaches for efficient radiological protection of the environment.
Topics: Ecosystem; Humans; Radiation Protection; Radiation, Ionizing; Research; Terminology as Topic
PubMed: 27058410
DOI: 10.1016/j.jenvrad.2016.03.021 -
Journal of Translational Medicine Mar 2022Medical applications of ionising radiation and associated radiation protection research often encounter long delays and inconsistent implementation when translated into...
BACKGROUND
Medical applications of ionising radiation and associated radiation protection research often encounter long delays and inconsistent implementation when translated into clinical practice. A coordinated effort is needed to analyse the research needs for innovation transfer in radiation-based high-quality healthcare across Europe which can inform the development of an innovation transfer framework tailored for equitable implementation of radiation research at scale.
METHODS
Between March and September 2021 a Delphi methodology was employed to gain consensus on key translational challenges from a range of professional stakeholders. A total of three Delphi rounds were conducted using a series of electronic surveys comprised of open-ended and closed-type questions. The surveys were disseminated via the EURAMED Rocc-n-Roll consortium network and prominent medical societies in the field. Approximately 350 professionals were invited to participate. Participants' level of agreement with each generated statement was captured using a 6-point Likert scale. Consensus was defined as median ≥ 4 with ≥ 60% of responses in the upper tertile of the scale. Additionally, the stability of responses across rounds was assessed.
RESULTS
In the first Delphi round a multidisciplinary panel of 20 generated 127 unique statements. The second and third Delphi rounds recruited a broader sample of 130 individuals to rate the extent to which they agreed with each statement as a key translational challenge. A total of 60 consensus statements resulted from the iterative Delphi process of which 55 demonstrated good stability. Ten statements were identified as high priority challenges with ≥ 80% of statement ratings either 'Agree' or 'Strongly Agree'.
CONCLUSION
A lack of interoperability between systems, insufficient resources, unsatisfactory education and training, and the need for greater public awareness surrounding the benefits, risks, and applications of ionising radiation were identified as principal translational challenges. These findings will help to inform a tailored innovation transfer framework for medical radiation research.
Topics: Consensus; Delphi Technique; Humans; Radiation Protection; Radiation, Ionizing; Surveys and Questionnaires
PubMed: 35303930
DOI: 10.1186/s12967-022-03344-4 -
Journal of Nuclear Medicine : Official... Apr 2015Radionuclide myocardial perfusion imaging (MPI) plays a vital role in the evaluation and management of patients with coronary artery disease. However, because of a steep... (Review)
Review
Radionuclide myocardial perfusion imaging (MPI) plays a vital role in the evaluation and management of patients with coronary artery disease. However, because of a steep growth in MPI in the mid 2000s, concerns about inappropriate use of MPI and imaging-related radiation exposure increased. In response, the professional societies developed appropriate-use criteria for MPI. Simultaneously, novel technology, image-reconstruction software for traditional scanners, and dedicated cardiac scanners emerged and facilitated the performance of MPI with low-dose and ultra-low-dose radiotracers. This paper provides a practical approach to performing low-radiation-dose MPI using traditional and novel technologies.
Topics: Coronary Angiography; Coronary Artery Disease; Heart; Humans; Image Processing, Computer-Assisted; Myocardial Perfusion Imaging; Patient Selection; Quality Control; Radiation Dosage; Radiation Protection; Radioisotopes; Software; Tomography, Emission-Computed, Single-Photon
PubMed: 25766891
DOI: 10.2967/jnumed.112.115097 -
Radiation and Environmental Biophysics Nov 2022A key activity of MELODI is to organise annual European meetings where scientific results and future directions and strategies of relevant research are discussed. The...
A key activity of MELODI is to organise annual European meetings where scientific results and future directions and strategies of relevant research are discussed. The annual meetings, previously organised solely under the auspices of MELODI are, since 2016, jointly organised by the European platforms and referred to as European Radiation Protection Weeks (ERPW). In addition to ERPW meetings, MELODI organises and finances annual workshops dedicated to specific topics. Outputs and recommendations from the meetings are published as review articles. The 2020 workshop focussed on one of the cross cutting topics: the effects of spatial and temporal variation in dose delivery on disease risk. The current issue of REBS includes five review articles from the workshop on the effects of spatial and temporal variation in dose delivery and this editorial is a short summary of their content.
Topics: Radiation Dosage; Radiation Protection
PubMed: 36280614
DOI: 10.1007/s00411-022-01002-3 -
Reviews on Environmental Health Sep 2023In March 2020, ICNIRP (the International Commission for Non-Ionizing Radiation Protection) published a set of guidelines for limiting exposure to electromagnetic fields... (Review)
Review
In March 2020, ICNIRP (the International Commission for Non-Ionizing Radiation Protection) published a set of guidelines for limiting exposure to electromagnetic fields (100 kHz to 300 GHz). ICNIRP claims this publication's view on EMF and health, a view usually termed "the thermal-only paradigm", is consistent with current scientific understanding. We investigated the literature referenced in ICNIRP 2020 to assess if the variation in authors and research groups behind it meets the fundamental requirement of constituting a broad scientific base and thus a view consistent with current scientific understanding, a requirement that such an important set of guidelines is expected to satisfy. To assess if this requirement has been met, we investigated the span of authors and research groups of the referenced literature of the ICNIRP 2020 Guidelines and annexes. Our analysis shows that ICNIRP 2020 itself, and in practice all its referenced supporting literature stem from a network of co-authors with just 17 researchers at its core, most of them affiliated with ICNIRP and/or the IEEE, and some of them being ICNIRP 2020 authors themselves. Moreover, literature reviews presented by ICNIRP 2020 as being from independent committees, are in fact products of this same informal network of collaborating authors, all committees having ICNIRP 2020 authors as members. This shows that the ICNIRP 2020 Guidelines fail to meet fundamental scientific quality requirements and are therefore not suited as the basis on which to set RF EMF exposure limits for the protection of human health. With its thermal-only view, ICNIRP contrasts with the majority of research findings, and would therefore need a particularly solid scientific foundation. Our analysis demonstrates the contrary to be the case. Hence, the ICNIRP 2020 Guidelines cannot offer a basis for good governance.
Topics: Humans; Radiation Protection; Radio Waves; Authorship; Electromagnetic Fields
PubMed: 35751553
DOI: 10.1515/reveh-2022-0037 -
Journal of Radiation Research Mar 2023Catheterization for structural heart disease (SHD) requires fluoroscopic guidance, which exposes health care professionals to radiation exposure risk. Nevertheless,...
Catheterization for structural heart disease (SHD) requires fluoroscopic guidance, which exposes health care professionals to radiation exposure risk. Nevertheless, existing freestanding radiation shields for anesthesiologists are typically simple, uncomfortable rectangles. Therefore, we devised a new perforated radiation shield that allows anesthesiologists and echocardiographers to access a patient through its apertures during SHD catheterization. No report of the relevant literature has described the degree to which the anesthesiologist's radiation dose can be reduced by installing radiation shields. For estimating whole-body doses to anesthesiologists and air dose distributions in the operating room, we used a Monte Carlo system for a rapid dose-estimation system used with interventional radiology. The simulations were performed under four conditions: no radiation shield, large apertures, small apertures and without apertures. With small apertures, the doses to the lens, waist and neck surfaces were found to be comparable to those of a protective plate without an aperture, indicating that our new radiation shield copes with radiation protection and work efficiency. To simulate the air-absorbed dose distribution, results indicated that a fan-shaped area of the dose rate decrease was generated in the area behind the shield, as seen from the tube sphere. For the aperture, radiation was found to wrap around the backside of the shield, even at a height that did not match the aperture height. The data presented herein are expected to be of interest to all anesthesiologists who might be involved in SHD catheterization. The data are also expected to enhance their understanding of radiation exposure protection.
Topics: Humans; Anesthesiologists; Monte Carlo Method; Radiation Protection; Radiation Exposure; Phantoms, Imaging; Radiation Dosage
PubMed: 36702614
DOI: 10.1093/jrr/rrac106