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Zhou F, Chen X, Liu H, Feng X, Ma T, Zhang Z. Characteristics of radioactive aerosols during the pre-decommission phase of the experimental shielding reactor. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:135120. [PMID: 38976960 DOI: 10.1016/j.jhazmat.2024.135120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 06/28/2024] [Accepted: 07/04/2024] [Indexed: 07/10/2024]
Abstract
The decommissioning of nuclear reactors is a global concern, in part because of the generation of radioactive aerosols that can lead to internal radiation exposure. At present, radioactive aerosols generated during nuclear decommissioning have not been actively studied, and data collected from the actual decommissioning are limited. This paper presents a study of radioactive aerosols generated during the pre-decommission phase of an experimental shielding reactor. Among all the on-site operations, cutting resulted in the highest levels of radioactivity. Plasma arc cutting, in particular, had a maximum gross α and β radioactivity over 0.10 and 0.14 Bq/m3, respectively. Assumed AMAD (activity median aerodynamic diameter) values are employed to assess the impact of particle size on the internal exposure dose resulting from the inhalation of 137Cs aerosols. This assessment is based on the Human Respiratory Tract Model of International Commission on Radiological Protection. When cutting stainless steel by plasma arc, the internal exposure dose caused by 137Cs aerosols with an AMAD of 0.1 µm is estimated to be nearly four times as that of aerosols with an AMAD of 10 µm. Results show that the internal exposure dose is highly dependent on the AMAD, implying the importance of measuring size-related parameters of radioactive aerosols in the future nuclear decommissioning. This study has revealed some characteristics of radioactive aerosols released in decommissioning operations, which can serve as a valuable reference for controlling and removing aerosols during the decommissioning of nuclear facilities.
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Affiliation(s)
- Fei Zhou
- Environmental Technology Division, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Xiaotong Chen
- Environmental Technology Division, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Haisheng Liu
- Division of Radiation Protection, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Xinchun Feng
- Division of Radiation Protection, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Tao Ma
- Reactor Operation Division, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Zhenzhong Zhang
- Environmental Technology Division, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China.
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2
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Chai W, Kong Y, Escalona MB, Hu C, Balajee AS, Huang Y. Evaluation of Low-dose Radiation-induced DNA Damage and Repair in 3D Printed Human Cellular Constructs. HEALTH PHYSICS 2023; Publish Ahead of Print:00004032-990000000-00091. [PMID: 37294952 DOI: 10.1097/hp.0000000000001709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
ABSTRACT DNA double-strand breaks (DSBs) induced by ionizing radiation (IR) are considered to be the most critical lesion that when unrepaired or misrepaired leads to genomic instability or cell death depending on the radiation exposure dose. The potential health risks associated with exposures of low-dose radiation are of concern since they are being increasingly used in diverse medical and non-medical applications. Here, we have used a novel human tissue-like 3-dimensional bioprint to evaluate low-dose radiation-induced DNA damage response. For the generation of 3-dimensional tissue-like constructs, human hTERT immortalized foreskin fibroblast BJ1 cells were extrusion printed and further enzymatically gelled in a gellan microgel-based support bath. Low-dose radiation-induced DSBs and repair were analyzed in the tissue-like bioprints by indirect immunofluorescence using a well-known DSB surrogate marker, 53BP1, at different post-irradiation times (0.5 h, 6 h, and 24 h) after treatment with various doses of γ rays (50 mGy, 100 mGy, and 200 mGy). The 53BP1 foci showed a dose dependent induction in the tissue bioprints after 30 min of radiation exposure and subsequently declined at 6 h and 24 h in a dose-dependent manner. The residual 53BP1 foci number observed at 24 h post-irradiation time for the γ-ray doses of 50 mGy, 100 mGy, and 200 mGy was not statistically different from mock treated bioprints illustrative of an efficient DNA repair response at these low-dose exposures. Similar results were obtained for yet another DSB surrogate marker, γ-H2AX (phosphorylated form of histone H2A variant) in the human tissue-like constructs. Although we have primarily used foreskin fibroblasts, our bioprinting approach-mimicking a human tissue-like microenvironment-can be extended to different organ-specific cell types for evaluating the radio-response at low-dose and dose-rates of IR.
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Affiliation(s)
- Wenxuan Chai
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611
| | - Yunfan Kong
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611
| | - Maria B Escalona
- Cytogenetic Biodosimetry Laboratory, Radiation Emergency Assistance Center/Training Site, Oak Ridge Associated Universities, 1299 Bethel Valley Road, Oak Ridge, TN 37830
| | - Chunshan Hu
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611
| | - Adayabalam S Balajee
- Cytogenetic Biodosimetry Laboratory, Radiation Emergency Assistance Center/Training Site, Oak Ridge Associated Universities, 1299 Bethel Valley Road, Oak Ridge, TN 37830
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3
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Shelly E, Waldron MG, Field E, Moore N, Young R, Scally A, England A, Maher M, McEntee MF. Cumulative Radiation Dose from Medical Imaging in Children with Congenital Heart Disease: A Systematic Review. CHILDREN (BASEL, SWITZERLAND) 2023; 10:children10040645. [PMID: 37189893 DOI: 10.3390/children10040645] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 03/18/2023] [Accepted: 03/27/2023] [Indexed: 05/17/2023]
Abstract
Children with congenital heart disease are exposed to repeated medical imaging throughout their lifetime. Although the imaging contributes to their care and treatment, exposure to ionising radiation is known to increase one's lifetime attributable risk of malignancy. A systematic search of multiple databases was performed. Inclusion and exclusion criteria were applied to all relevant papers and seven were deemed acceptable for quality assessment and risk of bias assessment. The cumulative effective dose (CED) varied widely across the patient cohorts, ranging from 0.96 mSv to 53.5 mSv. However, it was evident across many of the included studies that a significant number of patients were exposed to a CED >20 mSv, the current annual occupational exposure limit. Many factors affected the dose which patients received, including age and clinical demographics. The imaging modality which contributed the most radiation dose to patients was cardiology interventional procedures. Paediatric patients with congenital heart disease are at an increased risk of receiving an elevated cumulative radiation dose across their lifetime. Further research should focus on identifying risk factors for receiving higher radiation doses, keeping track of doses, and dose optimisation where possible.
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Affiliation(s)
- Emer Shelly
- Discipline of Medical Imaging & Radiation Therapy, University College Cork, T12AK54 Cork, Ireland
| | - Michael G Waldron
- Department of Radiology, Cork University Hospital, T12 DC4A Cork, Ireland
| | - Erica Field
- Discipline of Medical Imaging & Radiation Therapy, University College Cork, T12AK54 Cork, Ireland
| | - Niamh Moore
- Discipline of Medical Imaging & Radiation Therapy, University College Cork, T12AK54 Cork, Ireland
| | - Rena Young
- Discipline of Medical Imaging & Radiation Therapy, University College Cork, T12AK54 Cork, Ireland
| | - Andy Scally
- Discipline of Medical Imaging & Radiation Therapy, University College Cork, T12AK54 Cork, Ireland
| | - Andrew England
- Discipline of Medical Imaging & Radiation Therapy, University College Cork, T12AK54 Cork, Ireland
| | - Michael Maher
- Department of Radiology, Cork University Hospital, T12 DC4A Cork, Ireland
- Department of Medicine, University College Cork, T12 AK54 Cork, Ireland
| | - Mark F McEntee
- Discipline of Medical Imaging & Radiation Therapy, University College Cork, T12AK54 Cork, Ireland
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Pavletić B, Runzheimer K, Siems K, Koch S, Cortesão M, Ramos-Nascimento A, Moeller R. Spaceflight Virology: What Do We Know about Viral Threats in the Spaceflight Environment? ASTROBIOLOGY 2022; 22:210-224. [PMID: 34981957 PMCID: PMC8861927 DOI: 10.1089/ast.2021.0009] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Viruses constitute a significant part of the human microbiome, so wherever humans go, viruses are brought with them, even on space missions. In this mini review, we focus on the International Space Station (ISS) as the only current human habitat in space that has a diverse range of viral genera that infect microorganisms from bacteria to eukaryotes. Thus, we have reviewed the literature on the physical conditions of space habitats that have an impact on both virus transmissibility and interaction with their host, which include UV radiation, ionizing radiation, humidity, and microgravity. Also, we briefly comment on the practices used on space missions that reduce virus spread, that is, use of antimicrobial surfaces, spacecraft sterilization practices, and air filtration. Finally, we turn our attention to the health threats that viruses pose to space travel. Overall, even though efforts are taken to ensure safe conditions during human space travel, for example, preflight quarantines of astronauts, we reflect on the potential risks humans might be exposed to and how those risks might be aggravated in extraterrestrial habitats.
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Affiliation(s)
- Bruno Pavletić
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Aerospace Microbiology Research Group, Linder Hoehe, Cologne (Köln), Germany
| | - Katharina Runzheimer
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Aerospace Microbiology Research Group, Linder Hoehe, Cologne (Köln), Germany
| | - Katharina Siems
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Aerospace Microbiology Research Group, Linder Hoehe, Cologne (Köln), Germany
| | - Stella Koch
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Aerospace Microbiology Research Group, Linder Hoehe, Cologne (Köln), Germany
| | - Marta Cortesão
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Aerospace Microbiology Research Group, Linder Hoehe, Cologne (Köln), Germany
| | - Ana Ramos-Nascimento
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Aerospace Microbiology Research Group, Linder Hoehe, Cologne (Köln), Germany
| | - Ralf Moeller
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Aerospace Microbiology Research Group, Linder Hoehe, Cologne (Köln), Germany
- Address correspondence to: Ralf Moeller, German Aerospace Center (DLR), Institute of Aerospace Medicine, Radiation Biology Department, Aerospace Microbiology, Linder Hoehe, Building 24, Room 104, D-51147 Köln, Germany
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5
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Arnesdotter E, Rogiers V, Vanhaecke T, Vinken M. An overview of current practices for regulatory risk assessment with lessons learnt from cosmetics in the European Union. Crit Rev Toxicol 2021; 51:395-417. [PMID: 34352182 DOI: 10.1080/10408444.2021.1931027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Risk assessments of various types of chemical compounds are carried out in the European Union (EU) foremost to comply with legislation and to support regulatory decision-making with respect to their safety. Historically, risk assessment has relied heavily on animal experiments. However, the EU is committed to reduce animal experimentation and has implemented several legislative changes, which have triggered a paradigm shift towards human-relevant animal-free testing in the field of toxicology, in particular for risk assessment. For some specific endpoints, such as skin corrosion and irritation, validated alternatives are available whilst for other endpoints, including repeated dose systemic toxicity, the use of animal data is still central to meet the information requirements stipulated in the different legislations. The present review aims to provide an overview of established and more recently introduced methods for hazard assessment and risk characterisation for human health, in particular in the context of the EU Cosmetics Regulation (EC No 1223/2009) as well as the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Regulation (EC 1907/2006).
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Affiliation(s)
- Emma Arnesdotter
- Department of Pharmaceutical and Pharmacological Sciences, Research Group of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Vera Rogiers
- Department of Pharmaceutical and Pharmacological Sciences, Research Group of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Tamara Vanhaecke
- Department of Pharmaceutical and Pharmacological Sciences, Research Group of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Mathieu Vinken
- Department of Pharmaceutical and Pharmacological Sciences, Research Group of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels, Belgium
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6
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Talaat K, Xi J, Baldez P, Hecht A. Radiation Dosimetry of Inhaled Radioactive Aerosols: CFPD and MCNP Transport Simulations of Radionuclides in the Lung. Sci Rep 2019; 9:17450. [PMID: 31768010 PMCID: PMC6877642 DOI: 10.1038/s41598-019-54040-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 11/08/2019] [Indexed: 11/18/2022] Open
Abstract
Despite extensive efforts in studying radioactive aerosols, including the transmission of radionuclides in different chemical matrices throughout the body, the internal organ-specific radiation dose due to inhaled radioactive aerosols has largely relied on experimental deposition data and simplified human phantoms. Computational fluid-particle dynamics (CFPD) has proven to be a reliable tool in characterizing aerosol transport in the upper airways, while Monte Carlo based radiation codes allow accurate simulation of radiation transport. The objective of this study is to numerically assess the radiation dosimetry due to particles decaying in the respiratory tract from environmental radioactive exposures by coupling CFPD with Monte Carlo N-Particle code, version 6 (MCNP6). A physiologically realistic mouth-lung model extending to the bifurcation generation G9 was used to simulate airflow and particle transport within the respiratory tract. Polydisperse aerosols with different distributions were considered, and deposition distribution of the inhaled aerosols on the internal airway walls was quantified. The deposition mapping of radioactive aerosols was then registered to the respiratory tract of an image-based whole-body adult male model (VIP-Man) to simulate radiation transport and energy deposition. Computer codes were developed for geometry visualization, spatial normalization, and source card definition in MCNP6. Spatial distributions of internal radiation dosimetry were compared for different radionuclides (131I, 134,137Cs, 90Sr-90Y, 103Ru and 239,240Pu) in terms of the radiation fluence, energy deposition density, and dose per decay.
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Affiliation(s)
- Khaled Talaat
- Department of Nuclear Engineering, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Jinxiang Xi
- Department of Mechanical and Biomedical Engineering, California Baptist University, Riverside, CA, 92504, USA. .,Department of Biomedical Engineering, University of Massachusetts, Lowell, MA, 01854, USA.
| | - Phoenix Baldez
- Department of Nuclear Engineering, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Adam Hecht
- Department of Nuclear Engineering, University of New Mexico, Albuquerque, NM, 87131, USA
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7
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Abstract
The hormesis concept demonstrates that in contrast to the toxic effect of high doses of materials, irradiation, etc., low doses of them are beneficial and, in addition, help to eliminate (prevent) the deleterious effect of high doses given after it. By this effect, it is an important factor of (human) evolution protecting man from harmful impacts, similarly to the role of immunity. However, immunity is also continuously influenced by hormetic effects of environmental [chemical (pollutions), physical (background irradiations and heat), etc.] and medical (drugs and therapeutic irradiations) and food interactions. In contrast to earlier beliefs, the no-threshold irradiation dogma is not valid in low-dose domains and here the hormesis concept is valid. Low-dose therapeutic irradiation, as well as background irradiations (by radon spas or moderately far from the epicenter of atomic bomb or nuclear facilities), is rather beneficial than destructive and the fear from them seems to be unreasonable from immunological point of view. Practically, all immune parameters are beneficially influenced by all forms of low-dose radiations.
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Affiliation(s)
- György Csaba
- 1 Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, Hungary
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8
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Obodovskiy I. Radon. Miners of Uranium Copies and World Population. RADIATION 2019. [DOI: 10.1016/b978-0-444-63979-0.00047-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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9
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Rogalla P, Paravasthu M, Farrell C, Kandel S. Helical CT with variable target noise levels for dose reduction in chest, abdomen and pelvis CT. Eur Radiol 2018; 28:3922-3928. [DOI: 10.1007/s00330-018-5315-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 12/31/2017] [Accepted: 01/05/2018] [Indexed: 01/16/2023]
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10
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Mascalchi M, Sali L. Lung cancer screening with low dose CT and radiation harm-from prediction models to cancer incidence data. ANNALS OF TRANSLATIONAL MEDICINE 2017; 5:360. [PMID: 28936454 DOI: 10.21037/atm.2017.06.41] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Mario Mascalchi
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Lapo Sali
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
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11
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Koc U, Tan S, Ertem AG, Gumus M, Ozbek B, Erel O. Evaluation of thiol-disulphide homeostasis in radiation workers. Int J Radiat Biol 2017; 93:705-710. [DOI: 10.1080/09553002.2017.1304668] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Ural Koc
- Department of Radiology, Erzincan University Mengucek Gazi Training and Research Hospital, Erzincan, Turkey
| | - Sinan Tan
- Department of Radiology, Kırıkkale University, Kırıkkale, Turkey
| | - Ahmet Goktug Ertem
- Section of Cardiology, Ankara Yuksek Ihtisas Training and Research Hospital, Ankara, Turkey
| | - Mehmet Gumus
- Department of Radiology, Yıldırım Beyazıt University, Ankara, Turkey
| | - Betul Ozbek
- Section of Biochemistry, Ankara Ataturk Training and Research Hospital, Ankara, Turkey
| | - Ozcan Erel
- Department of Biochemistry, Yıldırım Beyazıt University, Ankara, Turkey
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Prasad KN, Cole WC, Hasse GM. Health Risks of Low Dose Ionizing Radiation in Humans: A Review. Exp Biol Med (Maywood) 2016; 229:378-82. [PMID: 15096649 DOI: 10.1177/153537020422900505] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Radiobiologists have been struggling to estimate the health risks from low doses of radiation in humans for decades. Health risks involve not only neoplastic diseases but also somatic mutations that may contribute to other illnesses (including birth defects and ocular maladies) and heritable mutations that may increase the risk of diseases in future generations. Low dose radiation-induced cancer in humans depends on several variables, and most of these variables are not possible to correct for in any epidemiologic study. Some of the confounding factors include (i) interaction of radiation with other physical (UV light), chemical, and biological mutagens and carcinogens in a synergistic manner; (ii) variation in repair mechanisms that depend on dose; (iii) variation in sensitivity of bystander cells to subsequent radiation exposure that depends on whether they have been pre- or postirradiated; and (iv) variation in adaptive response that depends on radiation doses and protective substances (antioxidants). In our opinion, both the linear no-threshold-response and the threshold-response models might not be suitable in predicting cancer risk at low radiation doses in a quantitative sense. Low doses of ionizing radiation should not be considered insignificant for risks of somatic and heritable, mutations and neoplastic and nonneoplastic diseases in humans.
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Affiliation(s)
- Kedar N Prasad
- Center for Vitamins and Cancer Research, School of Medicine, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
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13
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CaSO4:Dy,Mn: A new and highly sensitive thermoluminescence phosphor for versatile dosimetry. Radiat Phys Chem Oxf Engl 1993 2016. [DOI: 10.1016/j.radphyschem.2015.10.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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14
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Baldwin J, Grantham V. Radiation Hormesis: Historical and Current Perspectives. J Nucl Med Technol 2015; 43:242-6. [PMID: 26584616 DOI: 10.2967/jnmt.115.166074] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 10/02/2015] [Indexed: 11/16/2022] Open
Abstract
The purpose of this article is to provide the reader with a better understanding of radiation hormesis, the investigational research that supports or does not support the theory, and the relationship between the theory and current radiation safety guidelines and practices. The concept of radiation hormesis is known to nuclear medicine technologists, but understanding its complexities and the historical development of the theory may bring about a better understanding of radiation safety and regulations.
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Affiliation(s)
- Jonathan Baldwin
- Department of Medical Imaging and Radiation Sciences, College of Allied Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Vesper Grantham
- Department of Medical Imaging and Radiation Sciences, College of Allied Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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15
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Kostich M, Länge R. Ecotoxicology, Environmental Risk Assessment and Potential Impact on Human Health. PHARMACEUTICALS IN THE ENVIRONMENT 2015. [DOI: 10.1039/9781782622345-00180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This chapter examines potential risks posed by active pharmaceutical ingredients (APIs) present in the aquatic environment to humans and aquatic life. We begin by describing the mechanisms by which pharmaceuticals enter the vertebrate body, produce effects and leave the body. Then we describe theoretical and practical issues limiting the certainty which can be expected from risk estimates. This is followed by a description of particular considerations applicable to evaluation of human risks, along with a summary of methods and conclusions from some important studies examining those risks. A similar discussion of theoretical issues and selected data relevant for estimating risks to aquatic life is then presented. We finish by discussing potential contributions of antibiotics present in the environment to the development and spread of antibiotic resistance. We conclude that there are too few data to definitively address every concern, particularly risks to aquatic life and contributions to development of antibiotic resistance. On the other hand, available data suggest risks to humans are very low for all active pharmaceutical ingredients (APIs) and risks to aquatic life are very low for most APIs. Although aquatic risks cannot be as confidently ruled out for a few APIs, potential risks are probably limited to particularly contaminated regions in close vicinity to concentrated pollution sources, such as wastewater treatment plant outfalls.
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Madrigano RR, Abrão KC, Puchnick A, Regacini R. Evaluation of non-radiologist physicians' knowledge on aspects related to ionizing radiation in imaging. Radiol Bras 2015; 47:210-6. [PMID: 25741087 PMCID: PMC4337119 DOI: 10.1590/0100-3984.2013.1840] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 02/06/2014] [Indexed: 01/21/2023] Open
Abstract
Objective To assess the non-radiologist physicians' knowledge on the use of ionizing
radiation in imaging. Materials and Methods Cross-sectional study utilizing an anonymous questionnaire responded by physicians
in clinical and surgical specialties, divided into two parts as follows: one
including questions about the physicians' characteristics, frequency of imaging
studies requests and participation in professional updating events, and another
part including multiple choice questions approaching general knowledge about
radiation, optimization principles and radioprotection. Results From a total of 309 questionnaires, 120 (38.8%) were responded, 50% by physicians
in surgical specialties and 50% in clinical specialties; respectively 45% and 2.5%
of physicians responded that magnetic resonance imaging and ultrasonography use
ionizing radiation. Overall, the average grade was higher for surgical specialists
with no significant difference, except for the question about exposure in pregnant
women (p = 0.047). Physicians who are professionally updated,
particularly those attending clinical meetings (p = 0.050) and
participating in teaching activities (p = 0.047), showed
statistically superior knowledge about ionizing radiation as compared with
others. Conclusion The non-radiologist physicians' knowledge is heterogeneous and in some points
needs to be improved. Multidisciplinary clinical meetings and teaching activities
are important ways to disseminate information on the subject.
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Affiliation(s)
| | - Karen Cristine Abrão
- Teacher and Assistant Academic Director, Escola de Medicina da Universidade Anhembi Morumbi, PhD, Department of Gynecology and Obstetrics, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP, Brazil
| | - Andrea Puchnick
- Professor, Coordinator for Support to Teaching and Research, Department of Imaging Diagnosis, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM-Unifesp), São Paulo, SP, Brazil
| | - Rodrigo Regacini
- Teacher of Morphology and Radiology and Imaging Diagnosis, School of Medicine - Universidade Anhembi Morumbi, MD, Pediatric Radiologist and Fellow Master degree, Department of Imaging Diagnosis, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM-Unifesp), São Paulo, SP, Brazil
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17
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Shah S, Desouches SL, Lowe LH, Kasraie N, Reading B. Implementation of a competency check-off in diagnostic fluoroscopy for radiology trainees: impact on reducing radiation for three common fluoroscopic exams in children. Pediatr Radiol 2015; 45:228-34. [PMID: 25056230 DOI: 10.1007/s00247-014-3108-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 06/03/2014] [Accepted: 06/22/2014] [Indexed: 11/30/2022]
Abstract
BACKGROUND Fluoroscopy is an important tool for diagnosis in the pediatric population, but it carries the risk of radiation exposure. Because radiology resident education and experience in the use of fluoroscopy equipment in children vary, we implemented an intervention to standardize fluoroscopy training. OBJECTIVE The purpose of this study is to determine the impact of implementing a fluoroscopy competency check-off for radiology resident trainees aimed at decreasing radiation exposure in three common pediatric fluoroscopic studies. MATERIALS AND METHODS A fluoroscopy competency check-off form was developed for radiology resident trainees performing pediatric procedures. Techniques used to limit radiation exposure for common pediatric radiologic studies were reviewed as part of the check-off process. Pediatric radiologists supervised each trainee until they demonstrated competence to independently perform three specified procedures. Radiation dose was recorded for the three procedures, upper GI (UGI), voiding cystourethrogram (VCUG) and oropharyngeal (OPM) exams, over 6 months preceding and 6 months following implementation of the competency check-off. The mean cumulative dose for each procedure was compared before and after implementation of competency check-off using a Kruskal-Wallis test. RESULTS During the 12-month study period doses from 909 fluoroscopic procedures were recorded. In the 6 months preceding competency check-off implementation, procedures were performed by 24 radiology resident trainees including 171 UGI, 176 VCUG and 171 OPM exams. In the 6 months following competency check-off, 23 trainees performed 114 UGI, 145 VCUG and 132 OPM exams. After competency check-off implementation, a statistically significant reduction in average radiation dose was found for all three studies (P < 0.001). Median cumulative doses (mGy) were decreased by 33%, 36% and 13% for UGIs, VCUGs and OPMs, respectively. CONCLUSION Implementation of a competency check-off for radiology resident trainees can reduce average radiation doses in pediatric patients undergoing three common fluoroscopic studies.
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Affiliation(s)
- Sweta Shah
- Department of Radiology, University of Missouri-Kansas City SOM, 4401 Wornall Road, Kansas City, MO, 64111, USA
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Mayo-Smith WW, Hara AK, Mahesh M, Sahani DV, Pavlicek W. How I Do It: Managing Radiation Dose in CT. Radiology 2014; 273:657-72. [PMID: 25420167 DOI: 10.1148/radiol.14132328] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- William W Mayo-Smith
- From the Department of Radiology, Warren Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI (W.W.M.); Department of Radiology, Mayo Clinic Arizona, Scottsdale, Ariz (A.K.H., W.P.); Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Md (M.M.); and Department of Abdominal Imaging/Intervention, Massachusetts General Hospital, Boston, Mass (D.V.S.)
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Maglinte DDT, Hale DS, Sandrasegaran K. Comparison between dynamic cystocolpoproctography and dynamic pelvic floor MRI: pros and cons: which is the "functional" examination for anorectal and pelvic floor dysfunction? ACTA ACUST UNITED AC 2014; 38:952-73. [PMID: 22446896 DOI: 10.1007/s00261-012-9870-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
"Functional" imaging of anorectal and pelvic floor dysfunction has assumed an important role in the diagnosis and management of these disorders. Although defecography has been widely practiced for decades to evaluate the dynamics of rectal emptying, debate concerning its clinical relevance, how it should be done and interpreted continues. Due to the recognition of the association of defecatory disorders with pelvic organ prolapse in women, the need to evaluate the pelvic floor as a unit has arisen. To meet this need, defecography has been extended to include not only evaluation of defecation disorders but also the rest of the pelvic floor by opacifying the small bowel, vagina, and the urinary bladder. The term "dynamic cystocolpoproctography" (DCP) has been appropriately applied to this examination. Rectal emptying performed with DCP provides the maximum stress to the pelvic floor resulting in complete levator ani relaxation. In addition to diagnosing defecatory disorders, this method of examination demonstrates maximum pelvic organ descent and provides organ-specific quantification of organ prolapse, information that is only inferred by means of physical examination. It has been found to be of clinical value in patients with defecation disorders and the diagnosis of associated prolapse in other compartments that are frequently unrecognized by history taking and the limitations of physical examination. Pelvic floor anatomy is complex and DCP does not show the anatomical details pelvic magnetic resonance imaging (MRI) provides. Technical advances allowing acquisition of dynamic rapid MRI sequences has been applied to pelvic floor imaging. Early reports have shown that pelvic MRI may be a useful tool in pre-operative planning of these disorders and may lead to a change in surgical therapy. Predictions of hypothetical increase cancer incidence and deaths in patients exposed to radiation, the emergence of pelvic floor MRI in addition to questions relating to the clinical significance of DCP findings have added to these controversies. This review analyses the pros and cons between DCP and dynamic pelvic floor MRI, addresses imaging and interpretive controversies, and their relevance to clinical management.
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Affiliation(s)
- Dean D T Maglinte
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indiana University Hospital, 550 N, University Boulevard, UH0279, Indianapolis, IN, 46202-5253, USA,
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Abstract
Scientific method is inherently self-correcting. When different hypotheses are proposed, their study would result in the rejection of the invalid ones. If the study of a competing hypothesis is prevented because of the faith in an unverified one, scientific progress is stalled. This has happened in the study of low dose radiation. Though radiation hormesis was hypothesized to reduce cancers in 1980, it could not be studied in humans because of the faith in the unverified linear no-threshold model hypothesis, likely resulting in over 15 million preventable cancer deaths worldwide during the past two decades, since evidence has accumulated supporting the validity of the phenomenon of radiation hormesis. Since our society has been guided by scientific advisory committees that ostensibly follow the scientific method, the long duration of such large casualties is indicative of systemic deficiencies in the infrastructure that has evolved in our society for the application of science. Some of these deficiencies have been identified in a few elements of the scientific infrastructure, and remedial steps suggested. Identifying and correcting such deficiencies may prevent similar tolls in the future.
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Kaur R, Kaur J, Mahajan J, Kumar R, Arora S. Oxidative stress--implications, source and its prevention. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:1599-1613. [PMID: 24170504 DOI: 10.1007/s11356-013-2251-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 10/15/2013] [Indexed: 06/02/2023]
Abstract
Oxidative stress has been a major predicament of present day living. It has been the product of imbalance between the processes involved in free radical generation and their neutralization by enzymatic and non-enzymatic defence mechanisms. The oxidative stress has been contributed by numerous factors including heavy metals, organic compound-rich industrial effluents, air pollutants and changing lifestyle pattern focussing mainly on alcohol consumption, dietary habits, sun exposure, nuclear emissions, etc. The most common outcome of oxidative stress is the increased damage of lipid, DNA and proteins that resulted in the development of different pathologies. Among these pathologies, cancer is the most devastating and linked to multiple mutations arising due to oxidative DNA and protein damage that ultimately affect the integrity of the genome. The chemopreventive agents particularly nutraceuticals are found to be effective in reducing cancer incidences as these components have immense antioxidative, antimutagenic and antiproliferative potentials and are an important part of our dietary components. These secondary metabolites, due to their unique chemical structure, facilitate cell-to-cell communication, repair DNA damage by the downregulation of transcription factors and inhibit the activity of protein kinases and cytochrome P450-dependent mixed function oxidases. These phytochemicals, therefore, are most appropriate in combating oxidative stress-related disorders due to their tendency to exert better protective effect without having any distinct side effect.
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Affiliation(s)
- Rajbir Kaur
- Department of Botany, Sri Guru Teg Bahadur Khalsa College, Sri Anandpur Sahib, Ropar, 140118, Punjab, India.
| | - Jasmit Kaur
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, 143005, Punjab, India
| | - Jyoti Mahajan
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, 143005, Punjab, India
| | - Rakesh Kumar
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, 143005, Punjab, India
| | - Saroj Arora
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, 143005, Punjab, India
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Optimization of computed tomography (CT) arthrography of hip for the visualization of cartilage: an in vitro study. Skeletal Radiol 2014; 43:169-78. [PMID: 24281772 DOI: 10.1007/s00256-013-1759-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Revised: 10/11/2013] [Accepted: 10/13/2013] [Indexed: 02/02/2023]
Abstract
OBJECTIVE We sought to optimize the kilovoltage, tube current, and the radiation dose of computed tomographic arthrography of the hip joint using in vitro methods. MATERIALS AND METHODS A phantom was prepared using a left femoral head harvested from a patient undergoing total hip arthroplasty and packed in a condom filled with iodinated contrast. The right hip joint of a cadaver was also injected with iodinated contrast. The phantom and the cadaver were scanned using different values of peak kilovoltage (kVp) and tube current (milliamp seconds, mAs). Three different regions of interest (ROI) were drawn in the cartilage, subchondral bone plate, and intraarticular contrast. The attenuation values, contrast/noise ratio (CNR), and effective dose were calculated. Two independent observers classified the quality of the contrast-cartilage interface and the cartilage-subchondral bone plate interface as (1) diagnostic quality or (2) nondiagnostic quality. RESULTS Contrast, cartilage, and subchondral bone plate attenuation values decreased at higher kVp. CNR increased with both kVp and mAs. The qualitative analysis showed that in both phantom and cadaver, at 120 kVp and 50 mAs, the contrast-cartilage and cartilage-subchondral bone plate interfaces were of diagnostic quality, with an effective dose decreased to 0.5 MSv. CONCLUSIONS The absolute effective dose is not directly related to the quality of images but to the specific combination of kVp and mAs used for image acquisition. The combination of 120 kVp and 50 mAs can be suggested to decrease the dose without adversely affect the visibility of cartilage and subchondral bone plate.
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Abstract
Computed tomography plays a central and increasingly important role in medical imaging. From the very beginning more than 30 years ago, computed tomography technology has continued to develop and provide a wide variety of applications for evaluation of disorders of virtually any organ system in both children and adults. The benefits are particularly evident with the newer, fast, high-resolution multidetector scanners. However, these benefits must be carefully weighed against the potential risks, which include a relatively high radiation dose. Current research efforts are directed at both further improvements in the diagnostic potential with computed tomography, as well as managing radiation dose.
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Affiliation(s)
- Donald P Frush
- Division of Pediatric Radiology, Duke University Medical Center, 1905 McGovern-Davison Children's Health Center, Box 3808, Department of Radiology, Durham, NC 27710, USA.
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Abdollahi H. World high background natural radiation areas and public life: letter to the editor. RADIAT MEAS 2013. [DOI: 10.1016/j.radmeas.2012.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Oliai C, Yang LX. Radioprotectants to reduce the risk of radiation-induced carcinogenesis. Int J Radiat Biol 2013; 90:203-13. [PMID: 24164532 DOI: 10.3109/09553002.2014.859762] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE Development of radioprotective agents has focused primarily on cytoprotection from relatively high doses of therapeutic radiation and nuclear disasters. Epidemiological studies and radiobiological models report the potential for stochastic effects from relatively low-dose radiation exposure. Diagnostic studies like computed tomography (CT) expose the patient to a small but significant amount of radiation, which has been reported to increase the risk for carcinogenesis. Young patients expected to undergo multiple CT studies may benefit from a protective agent given prior to CT. This review includes published data of agents that have been shown to protect against radiation-induced carcinogenesis. A discussion follows regarding the data that describes the extent of radiation exposure during CT, as well as technical modifications, which also reduce radiation exposure. RESULTS/CONCLUSIONS Most experiments have used in vivo animal models or in vitro cell lines. Ethical barriers prevent large-scale human studies, although, there are two prospective human studies from the Chernobyl nuclear accident. Collectively, all of these studies provide evidence of statistically significant reductions in radiation-induced carcinogenesis. Protection is achieved by several mechanisms, which include free radical scavenging, caloric restriction, non-steroidal anti-inflammatory agents, humoral factors, and an oxidative agent. Enhanced efficacy is achieved when targeting multiple mechanisms. The data presented provides the scientific foundation for future development of a radioprotectant that may reduce the risk of carcinogenesis from low-dose exposure when certain at-risk populations undergo diagnostic studies like CT.
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Affiliation(s)
- Caspian Oliai
- Department of Radiation Oncology, California Pacific Medical Center , San Francisco, CA , USA
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Fletcher JG, Kofler JM, Coburn JA, Bruining DH, McCollough CH. Perspective on radiation risk in CT imaging. ACTA ACUST UNITED AC 2013; 38:22-31. [PMID: 22836811 DOI: 10.1007/s00261-012-9933-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Awareness of and communication about issues related to radiation dose are beneficial for patients, clinicians, and radiology departments. Initiating and facilitating discussions of the net benefit of CT by enlisting comparisons to more familiar activities, or by conveying that the anticipated radiation dose to an exam is similar to or much less than annual background levels help resolve the concerns of many patients and providers. While radiation risk estimates at the low doses associated with CT contain considerable uncertainty, we choose to err on the side of safety by assuming a small risk exists, even though the risk at these dose levels may be zero. Thus, radiologists should individualize CT scans according to patient size and diagnostic task to ensure that maximum benefit and minimum risk is achieved. However, because the magnitude of net benefit is driven by the potential benefit of a positive exam, radiation dose should not be reduced if doing so may compromise making an accurate diagnosis. The benefits and risks of CT are also highly individualized, and require consideration of many factors by patients, clinicians, and radiologists. Radiologists can assist clinicians and patients with understanding many of these factors, including test performance, potential patient benefit, and estimates of potential risk.
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Affiliation(s)
- Joel G Fletcher
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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Negrin LL, Vécsei V. Is a magnetic-manual targeting device an appealing alternative for distal locking of tibial intramedullary nails? ARCHIVES OF TRAUMA RESEARCH 2013; 2:16-20. [PMID: 24396784 PMCID: PMC3876508 DOI: 10.5812/atr.10638] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 02/26/2013] [Accepted: 03/02/2013] [Indexed: 11/22/2022]
Abstract
Background In order to enable a radiation-free, accurate and simple positioning of distal locking screws, a combined magnetic and manual targeting system has been developed by Sanatmetal®. Where a low-frequency magnetic field is initially used to detect the position of the first drill hole and three more holes can be found with a mechanical template. Objectives Our cadaver study was performed to evaluate the accuracy and efficiency of this device. Materials and Methods In two runs, 30 probands (group 1: 10 students; group 2: 10 residents; group 3: 10 attendings), none of who being familiar with the device, tested the radiation-free system using 60 intact cadaver tibias. Each proband performed the surgical procedure twice in succession. Results Referring to the first attempts, 9.6, 7.2 and 7.1 minutes were the time periods required to insert the four distal screws and the relevant values for the second attempts were 8.6, 6.3 and 6.2 minutes; in both cases revealing a significant difference between group 1 and 2 and group 1 and 3. Furthermore, the mean values within each group indicated a significant decrease of the test duration. Out of the 240 drillings, only one failure (group 1) occurred, representing an accuracy of 99.58 %. Of the probands, 90 % rated the targeting device better than the free-hand technique and 77 % at least attested a high user-friendliness. Conclusions Due to our satisfactory test results, the brief training, the steep learning curve and the radiation-free technique the new device has to be considered an appealing alternative for distal locking.
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Affiliation(s)
- Lukas L. Negrin
- Department of Trauma Surgery, Medical University of Vienna, Vienna, Austria
- Corresponding author: Lukas L. Negrin, Department of Trauma Surgery, Medical University of Vienna, Vienna, Austria. Tel: +43-1404005901, Fax: +43-1404005939, E-mail:
| | - Vilmos Vécsei
- Department of Trauma Surgery, Medical University of Vienna, Vienna, Austria
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Lumsdaine W, Enninghorst N, Hardy BM, Balogh ZJ. Patterns of CT use and surgical intervention in upper limb periarticular fractures at a level-1 trauma centre. Injury 2013; 44:471-4. [PMID: 23123000 DOI: 10.1016/j.injury.2012.09.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/18/2012] [Accepted: 09/30/2012] [Indexed: 02/02/2023]
Abstract
OBJECTIVES The universal availability of CT scanners has led to lower thresholds for imaging despite significant financial costs and radiation exposure. We hypothesised that this recent trend has increased the use of CT for upper limb periarticular fractures and led to more frequent operative management. METHOD A 5-year retrospective study (01/07/2005-30/06/2010) was performed on all adult patients with upper extremity periarticular fractures (OTA: 11, 13, 21 and 23) admitted to a level-1 trauma centre. Patients were identified from the institution's prospectively maintained OTA classification database. RESULTS A total of 1734 upper extremity periarticular fractures were identified in 1651 patients. 65% (1132/1734) were operated on. 32% (557/1734) had CT imaging and 78% (431/557) of these had operative management. CT use for all fractures and ages showed no change (0.56%/year, p = 0.210, r(2) = 0.457). Operative intervention increased at a rate of 2.17%/year (p = 0.004, r(2) = 0.959). Within each fracture type, CT rates showed no change. Operative management of proximal humerus and distal radius fractures became more frequent (6.30%/year, p = 0.002, r(2) = 0.969 and 0.96%/year, p = 0.046, r(2) = 0.784 respectively). Fractures around the elbow showed no change. In patients younger than 55 years, only proximal humerus fractures had more frequent imaging (3.17%/year, p = 0.023, r(2) = 0.866). In patients over 55 the frequency of CT scanning did not increase, but they were more frequently operated on (4.09%/year, p = 0.012, r(2) = 0.907). In older patients the rate of surgical intervention increased in all but the distal humerus region, Proximal humerus (6.19%/year, p = 0.015, r(2) = 0.894), proximal forearm (4.57%/year, p = 0.007, r(2) = 0.931) and distal radius (2.70%/year, p = 0.002, r(2) = 0.871). CONCLUSION During the examined 5-year period no increases of in CT imaging frequency were observed. The significantly increased number of operations among older patients is unlikely to be driven by imaging frequency.
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Affiliation(s)
- William Lumsdaine
- Department of Traumatology, Division of Surgery, John Hunter Hospital and University of Newcastle, Newcastle, NSW 2310, Australia
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Beathard GA, Urbanes A, Litchfield T. Radiation Dose Associated with Dialysis Vascular Access Interventional Procedures in the Interventional Nephrology Facility. Semin Dial 2013; 26:503-10. [DOI: 10.1111/sdi.12071] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Chen H, Rogalski MM, Anker JN. Advances in functional X-ray imaging techniques and contrast agents. Phys Chem Chem Phys 2012; 14:13469-86. [PMID: 22962667 PMCID: PMC3569739 DOI: 10.1039/c2cp41858d] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
X-rays have been used for non-invasive high-resolution imaging of thick biological specimens since their discovery in 1895. They are widely used for structural imaging of bone, metal implants, and cavities in soft tissue. Recently, a number of new contrast methodologies have emerged which are expanding X-ray's biomedical applications to functional as well as structural imaging. These techniques are promising to dramatically improve our ability to study in situ biochemistry and disease pathology. In this review, we discuss how X-ray absorption, X-ray fluorescence, and X-ray excited optical luminescence can be used for physiological, elemental, and molecular imaging of vasculature, tumors, pharmaceutical distribution, and the surface of implants. Imaging of endogenous elements, exogenous labels, and analytes detected with optical indicators will be discussed.
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Affiliation(s)
- Hongyu Chen
- Department of Chemistry, Center for Optical Materials Science and Engineering Technology (COMSET), Clemson University, Clemson, SC 29634, USA
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Lee DY, Bowen BP, Nguyen DH, Parsa S, Huang Y, Mao JH, Northen TR. Low-dose ionizing radiation-induced blood plasma metabolic response in a diverse genetic mouse population. Radiat Res 2012; 178:551-5. [PMID: 23051006 DOI: 10.1667/rr2990.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Understanding the biological effects and biochemical mechanisms of low-dose ionizing radiation (LDIR) is important for setting exposure limits for the safe use of nuclear power and medical diagnostic procedures. Although several studies have highlighted the effects of ionizing radiation on metabolism, most studies have focused on uniform genetic mouse populations. Here, we report the metabolic response to LDIR (10 cGy X ray) on a genetically diverse mouse population (142 mice) generated from a cross of radiation-sensitive (BALB/c) and radiation-resistant (SPRET/EiJ) parental strains. GC-TOF profiling of plasma metabolites was used to compare exposed vs. sham animals. From this, 16 metabolites were significantly altered in the LDIR treated vs. sham group. Use of two significantly altered metabolites, thymine and 2-monostearin, was found to effectively segregate the two treatments. Multivariate statistical analysis was used to identify genetic polymorphisms correlated with metabolite abundance (e.g., amino acids, fatty acids, nucleotides and TCA cycle intermediates). Genetic analysis of metabolic phenotypes showed suggestive linkages for fatty acid and amino acid metabolism. However, metabolite abundance was found to be a function of low-dose ionizing radiation exposure, and not of the underlying genetic variation.
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Affiliation(s)
- Do Yup Lee
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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McBride JF, Wardrop RM, Paxton BE, Mandrekar J, Fletcher JG. Effect on examination ordering by physician attitude, common knowledge, and practice behavior regarding CT radiation exposure. Clin Imaging 2012; 36:455-461.e1. [DOI: 10.1016/j.clinimag.2012.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 11/18/2011] [Accepted: 01/04/2012] [Indexed: 12/01/2022]
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Meer AB, Basu PA, Baker LC, Atlas SW. Exposure to ionizing radiation and estimate of secondary cancers in the era of high-speed CT scanning: projections from the Medicare population. J Am Coll Radiol 2012; 9:245-50. [PMID: 22469374 DOI: 10.1016/j.jacr.2011.12.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Accepted: 12/05/2011] [Indexed: 01/03/2023]
Abstract
PURPOSE The aims of this study were to analyze the distribution and amount of ionizing radiation delivered by CT scans in the modern era of high-speed CT and to estimate cancer risk in the elderly, the patient group most frequently imaged using CT scanning. METHODS A retrospective cohort study was conducted using Medicare claims spanning 8 years (1998-2005) to assess CT use. The data were analyzed in two 4-year cohorts, 1998 to 2001 (n = 5,267,230) and 2002 to 2005 (n = 5,555,345). The number and types of CT scans each patient received over the 4-year periods were analyzed to determine the percentage of patients exposed to threshold radiation of 50 to 100 mSv (defined as low) and >100 mSv (defined as high). The National Research Council's Biological Effects of Ionizing Radiation VII models were used to estimate the number of radiation-induced cancers. RESULTS CT scans of the head were the most common examinations in both Medicare cohorts, but abdominal imaging delivered the greatest proportion (43% in the first cohort and 40% in the second cohort) of radiation. In the 1998 to 2001 cohort, 42% of Medicare patients underwent CT scans, with 2.2% and 0.5% receiving radiation doses in the low and high ranges, respectively. In the 2002 to 2005 cohort, 50% of Medicare patients received CT scans, with 4.2% and 1.2% receiving doses in the low and high ranges. In the two populations, 1,659 (0.03%) and 2,185 (0.04%) cancers related to ionizing radiation were estimated, respectively. CONCLUSIONS Although radiation doses have been increasing along with the increasing reliance on CT scans for diagnosis and therapy, using conservative estimates with worst-case scenario methodology, the authors found that the risk for secondary cancers is low in older adults, the group subjected to the most frequent CT scanning. Trends showing increasing use, however, underscore the importance of monitoring CT utilization and its consequences.
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Affiliation(s)
- Aabed B Meer
- Department of Radiology, Stanford University Medical Center, Stanford, California 94305, USA
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Abstract
The use of ionizing radiation for medical diagnostic tests and interventional procedures has grown substantially over the past 2 decades, and there is now considerable concern expressed in both the medical literature and the lay press of the harmful effects of radiation exposure. Although there is some controversy regarding whether this medical radiation is actually harmful, minimizing the dose to the patient is logical and a basic part of proper care. To do this, clinicians must have an understanding of the amount of radiation that is involved with each test. Physicians have a responsibility to keep the level of radiation exposure as low as reasonably achievable. A number of simple and common sense measures can help achieve this goal. Encouragingly, there are also numerous new technologies which can substantially lower radiation dose, especially in cardiovascular studies. This review will highlight various ways to reduce radiation in cardiovascular imaging.
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Abstract
The current radiation safety paradigm using the linear no-threshold (LNT) model is based on the premise that even the smallest amount of radiation may cause mutations increasing the risk of cancer. Autopsy studies have shown that the presence of cancer cells is not a decisive factor in the occurrence of clinical cancer. On the other hand, suppression of immune system more than doubles the cancer risk in organ transplant patients, indicating its key role in keeping occult cancers in check. Low dose radiation (LDR) elevates immune response, and so it may reduce rather than increase the risk of cancer. LNT model pays exclusive attention to DNA damage, which is not a decisive factor, and completely ignores immune system response, which is an important factor, and so is not scientifically justifiable. By not recognizing the importance of the immune system in cancer, and not exploring exercise intervention, the current paradigm may have missed an opportunity to reduce cancer deaths among atomic bomb survivors. Increased antioxidants from LDR may reduce aging-related non-cancer diseases since oxidative damage is implicated in these. A paradigm shift is warranted to reduce further casualties, reduce fear of LDR, and enable investigation of potential beneficial applications of LDR.
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Strauchler D, Freeman K, Miller TS. The Impact of Socioeconomic Status and Comorbid Medical Conditions on Ionizing Radiation Exposure From Diagnostic Medical Imaging in Adults. J Am Coll Radiol 2012; 9:58-63. [DOI: 10.1016/j.jacr.2011.07.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 07/11/2011] [Indexed: 10/14/2022]
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Abstract
Computerized tomography (CT) is an extremely powerful imaging modality, which provides extremely valuable information for the diagnosis, staging, and management of pediatric solid tumors. In recent years, the concern of potential risks associated with ionizing radiation from diagnostic imaging - especially from CT - has greatly increased. In children with cancer the radiation burden from CT studies can easily accumulate because of repeated studies for disease staging, assessment of response to therapy, and follow up. The purpose of this article is to review the role of CT and its imaging key points for diagnosis, staging and planning surgical excision of common extracranial pediatric tumors, according to protocol specific imaging guidelines. The issue of the radiation burden from CT in children with cancer, and criteria of good practice to reduce it, will also be discussed.
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Affiliation(s)
- Claudio Granata
- Department of Radiology, IRCCS Giannina Gaslini Hospital, Genoa, Italy.
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Tamm EP, Rong XJ, Cody DD, Ernst RD, Fitzgerald NE, Kundra V. Quality initiatives: CT radiation dose reduction: how to implement change without sacrificing diagnostic quality. Radiographics 2011; 31:1823-32. [PMID: 21969662 DOI: 10.1148/rg.317115027] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The risks and benefits of using computed tomography (CT) as opposed to another imaging modality to accomplish a particular clinical goal should be weighed carefully. To accurately assess radiation risks and keep radiation doses as low as reasonably achievable, radiologists must be knowledgeable about the doses delivered during various types of CT studies performed at their institutions. The authors of this article propose a process improvement approach that includes the estimation of effective radiation dose levels, formulation of dose reduction goals, modification of acquisition protocols, assessment of effects on image quality, and implementation of changes necessary to ensure quality. A first step toward developing informed radiation dose reduction goals is to become familiar with the radiation dose values and radiation-associated health risks reported in the literature. Next, to determine the baseline dose values for a CT study at a particular institution, dose data can be collected from the CT scanners, interpreted, tabulated, and graphed. CT protocols can be modified to reduce overall effective dose by using techniques such as automated exposure control and iterative reconstruction, as well as by decreasing the number of scanning phases, increasing the section thickness, and adjusting the peak voltage (kVp setting), tube current-time product (milliampere-seconds), and pitch. Last, PDSA (plan, do, study, act) cycles can be established to detect and minimize negative effects of dose reduction methods on image quality.
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Affiliation(s)
- Eric P Tamm
- Department of Diagnostic Imaging, University of Texas MD Anderson Cancer Center, Unit 1473, P.O. Box 301402, Houston, TX 77230-1402, USA.
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Fletcher JG, Fidler JL, Bruining DH, Huprich JE. New concepts in intestinal imaging for inflammatory bowel diseases. Gastroenterology 2011; 140:1795-806. [PMID: 21530746 DOI: 10.1053/j.gastro.2011.02.013] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 02/08/2011] [Accepted: 02/11/2011] [Indexed: 12/26/2022]
Abstract
In the last decade, multiple imaging technologies have been developed that improve visualization of the mucosal, mural, and perienteric inflammation associated with inflammatory bowel diseases. Whereas these technologies have traditionally been used to detect and stage suspected enteric inflammation, we review new, emerging roles in detecting clinically occult inflammation (in asymptomatic patients) and inflammatory complications, predicting response prior to therapy, assessing response after therapy, and enteric healing. We compare the relative performance of these technologies in detecting inflammation, focusing on their advantages and disadvantages and how they might complement each other. We also discuss their potential benefits for patients and clinical trials, reviewing technologic developments and areas of research that could provide important insights into the pathophysiology of inflammatory bowel diseases-related enteric inflammation.
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Affiliation(s)
- Joel G Fletcher
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
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Rhomberg LR, Goodman JE, Haber LT, Dourson M, Andersen ME, Klaunig JE, Meek B, Price PS, McClellan RO, Cohen SM. Linear low-dose extrapolation for noncancer heath effects is the exception, not the rule. Crit Rev Toxicol 2011; 41:1-19. [PMID: 21226629 PMCID: PMC3038594 DOI: 10.3109/10408444.2010.536524] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The nature of the exposure-response relationship has a profound influence on risk analyses. Several arguments have been proffered as to why all exposure-response relationships for both cancer and noncarcinogenic endpoints should be assumed to be linear at low doses. We focused on three arguments that have been put forth for noncarcinogens. First, the general "additivity-to-background" argument proposes that if an agent enhances an already existing disease-causing process, then even small exposures increase disease incidence in a linear manner. This only holds if it is related to a specific mode of action that has nonuniversal properties-properties that would not be expected for most noncancer effects. Second, the "heterogeneity in the population" argument states that variations in sensitivity among members of the target population tend to "flatten out and linearize" the exposure-response curve, but this actually only tends to broaden, not linearize, the dose-response relationship. Third, it has been argued that a review of epidemiological evidence shows linear or no-threshold effects at low exposures in humans, despite nonlinear exposure-response in the experimental dose range in animal testing for similar endpoints. It is more likely that this is attributable to exposure measurement error rather than a true nonthreshold association. Assuming that every chemical is toxic at high exposures and linear at low exposures does not comport to modern-day scientific knowledge of biology. There is no compelling evidence-based justification for a general low-exposure linearity; rather, case-specific mechanistic arguments are needed.
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Takai D, Todate A, Yanai T, Ichinohe K, Oghiso Y. Enhanced transplantability of a cell line from a murine ovary granulosa cell tumour in syngeneic B6C3F1mice continuously irradiated with low dose-rate gamma-rays. Int J Radiat Biol 2011; 87:729-35. [DOI: 10.3109/09553002.2010.545861] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Blankenbecler R. Radiation worker protection by exposure scheduling. Dose Response 2011; 9:465-70. [PMID: 22461756 DOI: 10.2203/dose-response.11-029.blankenbecler] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The discovery of the protective adaptive response of cells to a low dose of radiation suggests applications to radiation worker/first responder protection. Its use in cancer radiotherapy has been discussed in a separate publication. This paper describes simple changes in scheduling that can make use of these beneficial adaptive effects for protection. No increase in total exposure is necessary, only a simple change in the timing of radiation exposure. A low dose of radiation at a sufficient dose rate will trigger the adaptive response. This in turn will offer a considerable protection against the damage from a subsequent high dose. A simple scenario is discussed as well as a brief review of the experimental basis of the adaptive response.
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Abstract
Cardiac computed tomography (CT) dosimetry makes use of two radiation parameters: a volume CT dose index (CTDI) and a dose length product (DLP). The volume CTDI quantifies the intensity of the radiation used to perform CT examinations, whereas DLP quantifies the amount of radiation used. CTDI metrics can be converted into patient dose metrics by using dose/CTDI conversion factors. In cardiac CT imaging, these need to take into account the x-ray tube voltage, scan length, and scan region, as well as patient size. Organ doses to patients in cardiac CT can be converted into cancer risks when patient demographic factors are taken into account. A risk analysis of patients undergoing cardiac CT angiography at our institution showed that a majority (62%) were males, with a median age of approximately 60 years and a median weight of approximately 90 kg. The median DLP was approximately 1100 mGy cm, corresponding to an effective dose of approximately 29 mSv in normal-sized patients. The average patient lifetime risk for a radiation-induced cancer was estimated to be 0.12%, with 85% of it attributed to lung cancer. Patients with an age and weight at the 10th percentile, who also received a DLP at the 90th percentile, would have cancer risk estimates approximately double the average value. Radiation risks are required to determine whether examinations are indicated, defined as examinations in which individual patient benefit exceeds corresponding patient risk. Understanding radiation risks in cardiac CT encourages operators to use the least amount of radiation to achieve satisfactory diagnostic performance.
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Knowledge and Attitudes of Emergency Department Patients Regarding Radiation Risk of CT: Effects of Age, Sex, Race, Education, Insurance, Body Mass Index, Pain, and Seriousness of Illness. AJR Am J Roentgenol 2010; 195:1151-8. [DOI: 10.2214/ajr.09.3847] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abstract
In radiotherapy, a large radiation dose must be applied to both cancer and neighboring healthy cells. Recent experiments have shown that a low dose of ionizing radiation turns on certain protective mechanisms that allow a cell to better survive a subsequent high dose of radiation. This adaptive response can have important and positive consequences for radiotherapy. This paper describes a simple change in treatment procedures to make use of these beneficial effects. A low dose applied only to the healthy cells will probably produce some damage. However, it will also start the adaptive response which will yield increased protection when the large therapeutic dose is applied. The resultant immediate damage will be thereby reduced as well as the probability that the high dose therapy itself will induce a subsequent secondary cancer. After a brief historical review, the effects of a low radiation dose on a canine cancer cell line will be discussed as well as trials of the suggested pre-dose therapy on canine cancer patients undergoing standard radiation therapy.
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Affiliation(s)
- Richard Blankenbecler
- Professor emeritus, Stanford Linear Accelerator Center, Stanford University, Stanford CA; Adjunct Professor of Physics, Virginia Tech, Blacksburg VA; Adjunct Fellow, Nevada Cancer Institute, Las Vegas NV
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Utilization guidelines for reducing radiation exposure in the evaluation of aneurysmal subarachnoid hemorrhage: A practice quality improvement project. AJR Am J Roentgenol 2010; 195:176-80. [PMID: 20566813 DOI: 10.2214/ajr.09.3786] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to reduce the cumulative radiation exposure from CT of patients with aneurysmal subarachnoid hemorrhage. MATERIALS AND METHODS Baseline data on 30 patients with aneurysmal subarachnoid hemorrhage were collected retrospectively for all CT examinations of the head performed throughout the hospital course. Radiation exposure estimates were obtained by recording dose-length products for each examination. As a departmental practice quality improvement project, an imaging protocol was implemented that included utilization guidelines to reduce radiation exposure in CTA and CT perfusion examinations performed to detect vasospasm in patients with aneurysmal subarachnoid hemorrhage. Ten months after implementation of this protocol, data on 30 additional patients were analyzed. Means, medians, and SD estimates were compared for cumulative radiation exposure and absolute numbers of each examination. RESULTS Sixty patients were included in the study: 30 patients at baseline and 30 patients after implementation of the quality improvement plan. These patients underwent 435 CT examinations: 248 examinations at baseline and 187 examinations with the new protocol. With the new algorithm, the mean number of CT examinations per patient was 5.8 compared with 7.8 at baseline, representing a decrease of 25.6%. The number of CT perfusion examinations per patient decreased 32.1%. Overall, there was a 12.1% decrease in cumulative radiation exposure (p > 0.05). CONCLUSION With the structured imaging algorithm, the cumulative radiation exposure and number of CT examinations of the head decreased among patients with aneurysmal subarachnoid hemorrhage because utilization guidelines defined the appropriate imaging time points for detection of vasospasm. Application of these methods to other patient populations with high use of CT may reduce cumulative radiation exposure while the clinical benefits of imaging are maintained.
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Blecher CM. Alarm about computed tomography scans is unjustified. Med J Aust 2010; 192:723-4. [DOI: 10.5694/j.1326-5377.2010.tb03718.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 04/20/2010] [Indexed: 11/17/2022]
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Radiation-induced olfactory neuroblastoma: a new etiology is possible. Oral Maxillofac Surg 2010; 15:71-7. [PMID: 20512390 DOI: 10.1007/s10006-010-0234-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2010] [Accepted: 05/17/2010] [Indexed: 10/19/2022]
Abstract
PURPOSE Radiation-induced olfactory neuroblastoma (ONB) is an uncommon neoplasm that is generally associated with a poor prognosis. We describe a new case of olfactory neuroblastoma in a patient previously treated for astrocytoma with holocranial radiotherapy 9 years ago. MATERIALS AND METHODS We reviewed the medical records of four patients with radiation-induced olfactory neuroblastoma between 2001 and 2009. RESULTS This work supports the idea that ONB can be induced by radiation. CONCLUSIONS As radiotherapy is a standard treatment in other tumors, clinicians must be aware of the possibility of a second tumor induced by radiation.
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Abstract
The linear no-threshold (LNT) dose-effect relationship has been consistently used by most radiation epidemiologists to estimate cancer mortality risk. The large scattering of data by International Agency for Research on Cancer, IARC (Vrijheid et al. 2007; Therry-Chef et al. 2007; Cardis et al. 2007), interpreted in accordance with LNT, has been previously demonstrated (Fornalski and Dobrzyński 2009). Using conventional and Bayesian methods the present paper demonstrates that the standard mortality ratios (SMRs), lower in the IARC cohort of exposed nuclear workers than in the non exposed group, should be considered as a hormetic effect, rather than a healthy worker effect (HWE) as claimed by the IARC group.
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