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Sample records for cap-88 dose risk

  1. NESHAP Area-Specific Dose-Release Factors for Potential Onsite Member-of-the-Public Locations at SRS using CAP88-PC Version 4.0

    Energy Technology Data Exchange (ETDEWEB)

    Trimor, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-08-09

    The Environmental Protection Agency (EPA) requires the use of the computer model CAP88-PC to estimate the total effective doses (TED) for demonstrating compliance with 40 CFR 61, Subpart H (EPA 2006), the National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations. As such, CAP88 Version 4.0 was used to calculate the receptor dose due to routine atmospheric releases at the Savannah River Site (SRS). For estimation, NESHAP dose-release factors (DRFs) have been supplied to Environmental Compliance and Area Closure Projects (EC&ACP) for many years. DRFs represent the dose to a maximum receptor exposed to 1 Ci of a specified radionuclide being released into the atmosphere. They are periodically updated to include changes in the CAP88 version, input parameter values, site meteorology, and location of the maximally exposed individual (MEI). In this report, the DRFs were calculated for potential radionuclide atmospheric releases from 13 SRS release points. The three potential onsite MEI locations to be evaluated are B-Area, Three Rivers Landfill (TRL), and Savannah River Ecology Lab Conference Center (SRELCC) with TRL’s onsite workers considered as members-of-the-public, and the potential future constructions of dormitories at SRELCC and Barracks at B-Area. Each MEI location was evaluated at a specified compass sector with different area to receptor distances and was conducted for both ground-level and elevated release points. The analysis makes use of area-specific meteorological data (Viner 2014). The resulting DRFs are compared to the 2014 NESHAP offsite MEI DRFs for three operational areas; A-Area, H-Area, and COS for a release rate of 1 Ci of tritium oxide at 0 ft. elevation. CAP88 was executed again using the 2016 NESHAP MEI release rates for 0 and 61 m stack heights to determine the radionuclide dose at TRL from the center-of-site (COS).

  2. NESHAP Dose-Release Factor Isopleths for Five Source-to-Receptor Distances from the Center of Site and H-Area for all Compass Sectors at SRS using CAP88-PC Version 4.0

    Energy Technology Data Exchange (ETDEWEB)

    Trimor, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-08-09

    The Environmental Protection Agency (EPA) requires the use of the computer model CAP88-PC to estimate the total effective doses (TED) for demonstrating compliance with 40 CFR 61, Subpart H (EPA 2006), the National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations. As such, CAP88 Version 4.0 was used to calculate the receptor dose due to routine atmospheric releases at the Savannah River Site (SRS). For estimation, NESHAP dose-release factors (DRFs) have been supplied to Environmental Compliance and Area Closure Projects (EC&ACP) for many years. DRFs represent the dose to a maximum receptor exposed to 1 Ci of a specified radionuclide being released into the atmosphere. They are periodically updated to include changes in the CAP88 version, input parameter values, site meteorology, and location of the maximally exposed individual (MEI). This report presents the DRFs of tritium oxide released at two onsite locations, center-of-site (COS) and H-Area, at 0 ft. elevation to maximally exposed individuals (MEIs) located 1000, 3000, 6000, 9000, and 12000 meters from the release areas for 16 compass sectors. The analysis makes use of area-specific meteorological data (Viner 2014).

  3. The comparison of CAP88-PC version 2.0 versus CAP88-PC version 1.0

    International Nuclear Information System (INIS)

    Yakubovich, B.A.; Klee, K.O.; Palmer, C.R.; Spotts, P.B.

    1997-12-01

    40 CFR Part 61 (Subpart H of the NESHAP) requires DOE facilities to use approved sampling procedures, computer models, or other approved procedures when calculating Effective Dose Equivalent (EDE) values to members of the public. Currently version 1.0 of the approved computer model CAP88-PC is used to calculate EDE values. The DOE has upgraded the CAP88-PC software to version 2.0. This version provides simplified data entry, better printing characteristics, the use of a mouse, and other features. The DOE has developed and released version 2.0 for testing and comment. This new software is a WINDOWS based application that offers a new graphical user interface with new utilities for preparing and managing population and weather data, and several new decay chains. The program also allows the user to view results before printing. This document describes a test that confirmed CAP88-PC version 2.0 generates results comparable to the original version of the CAP88-PC program

  4. Assessment of radionuclide databases in CAP88 mainframe version 1.0 and Windows-based version 3.0.

    Science.gov (United States)

    LaBone, Elizabeth D; Farfán, Eduardo B; Lee, Patricia L; Jannik, G Timothy; Donnelly, Elizabeth H; Foley, Trevor Q

    2009-09-01

    In this study the radionuclide databases for two versions of the Clean Air Act Assessment Package-1988 (CAP88) computer model were assessed in detail. CAP88 estimates radiation dose and the risk of health effects to human populations from radionuclide emissions to air. This program is used by several U.S. Department of Energy (DOE) facilities to comply with National Emission Standards for Hazardous Air Pollutants regulations. CAP88 Mainframe, referred to as version 1.0 on the U.S. Environmental Protection Agency Web site (http://www.epa.gov/radiation/assessment/CAP88/), was the very first CAP88 version released in 1988. Some DOE facilities including the Savannah River Site still employ this version (1.0) while others use the more user-friendly personal computer Windows-based version 3.0 released in December 2007. Version 1.0 uses the program RADRISK based on International Commission on Radiological Protection Publication 30 as its radionuclide database. Version 3.0 uses half-life, dose, and risk factor values based on Federal Guidance Report 13. Differences in these values could cause different results for the same input exposure data (same scenario), depending on which version of CAP88 is used. Consequently, the differences between the two versions are being assessed in detail at Savannah River National Laboratory. The version 1.0 and 3.0 database files contain 496 and 838 radionuclides, respectively, and though one would expect the newer version to include all the 496 radionuclides, 35 radionuclides are listed in version 1.0 that are not included in version 3.0. The majority of these has either extremely short or long half-lives or is no longer in production; however, some of the short-lived radionuclides might produce progeny of great interest at DOE sites. In addition, 122 radionuclides were found to have different half-lives in the two versions, with 21 over 3 percent different and 12 over 10 percent different.

  5. Validation test for CAP88 predictions of tritium dispersion at Los Alamos National Laboratory.

    Science.gov (United States)

    Michelotti, Erika; Green, Andrew; Whicker, Jeffrey; Eisele, William; Fuehne, David; McNaughton, Michael

    2013-08-01

    Gaussian plume models, such as CAP88, are used regularly for estimating downwind concentrations from stack emissions. At many facilities, the U.S. Environmental Protection Agency (U.S. EPA) requires that CAP88 be used to demonstrate compliance with air quality regulations for public protection from emissions of radionuclides. Gaussian plume models have the advantage of being relatively simple and their use pragmatic; however, these models are based on simplifying assumptions and generally they are not capable of incorporating dynamic meteorological conditions or complex topography. These limitations encourage validation tests to understand the capabilities and limitations of the model for the specific application. Los Alamos National Laboratory (LANL) has complex topography but is required to use CAP88 for compliance with the Clean Air Act Subpart H. The purpose of this study was to test the accuracy of the CAP88 predictions against ambient air measurements using released tritium as a tracer. Stack emissions of tritium from two LANL stacks were measured and the dispersion modeled with CAP88 using local meteorology. Ambient air measurements of tritium were made at various distances and directions from the stacks. Model predictions and ambient air measurements were compared over the course of a full year's data. Comparative results were consistent with other studies and showed the CAP88 predictions of downwind tritium concentrations were on average about three times higher than those measured, and the accuracy of the model predictions were generally more consistent for annual averages than for bi-weekly data.

  6. Comparisons of CAP88PC version 2.0 default parameters to site specific inputs

    International Nuclear Information System (INIS)

    Lehto, M. A.; Courtney, J. C.; Charter, N.; Egan, T.

    2000-01-01

    The effects of varying the input for the CAP88PC Version 2.0 program on the total effective dose equivalents (TEDEs) were determined for hypothetical releases from the Hot Fuel Examination Facility (HFEF) located at the Argonne National Laboratory site on the Idaho National Engineering and Environmental Laboratory (INEEL). Values for site specific meteorological conditions and agricultural production parameters were determined for the 80 km radius surrounding the HFEF. Four nuclides, 3 H, 85 Kr, 129 I, and 137 Cs (with its short lived progeny, 137m Ba) were selected for this study; these are the radioactive materials most likely to be released from HFEF under normal or abnormal operating conditions. Use of site specific meteorological parameters of annual precipitation, average temperature, and the height of the inversion layer decreased the TEDE from 137 Cs- 137m Ba up to 36%; reductions for other nuclides were less than 3%. Use of the site specific agricultural parameters reduced TEDE values between 7% and 49%, depending on the nuclide. Reductions are associated with decreased committed effective dose equivalents (CEDEs) from the ingestion pathway. This is not surprising since the HFEF is located well within the INEEL exclusion area, and the surrounding area closest to the release point is a high desert with limited agricultural diversity. Livestock and milk production are important in some counties at distances greater than 30 km from the HFEF

  7. Low Dose Risk, Decisions, and Risk Communication

    International Nuclear Information System (INIS)

    Flynn, James

    2002-01-01

    The overall research objective was to establish new levels of information about how people, groups, and communities respond to low dose radiation exposure. This is basic research into the social psychology of individual, group, and community responses to radiation exposures. The results of this research are directed to improving risk communication and public participation in management of environmental problems resulting from low dose radiation

  8. Radiation. Doses, effect, risk

    International Nuclear Information System (INIS)

    Vapirev, E.; Todorov, P.

    1994-12-01

    This book outlines in a popular form the topic of ionizing radiation impacts on living organisms. It contains data gathered by ICRP for a period of 35 years. The essential dosimetry terms and units are presented. Natural and artificial sources of ionizing radiation are described. Possible biological radiation effects and diseases as a consequence of external and internal irradiation at normal and accidental conditions are considered. An assessment of genetic risk for human populations is presented and the concept of 'acceptable risk' is discussed

  9. LOW DOSE RISK, DECISIONS, and RISK COMMUNICATION

    International Nuclear Information System (INIS)

    Flynn, James

    2002-01-01

    The objective of this project is to conduct basic research on how people receive, evaluate, and form positions on scientific information and its relationship to low-dose radiation exposure. There are three major areas of study in our research program. First is the development of theories, frameworks and concepts essential to guiding data collection and analysis. The second area is a program of experimental studies on risk perception, evaluation of science information, and the structure of individual positions regarding low-dose exposures. Third is the community-level studies to examine and record how the social conditions, under which science communications take place, influence the development of attitudes and opinions about: low-dose exposures, the available management options, control of radiation risks, and preferences for program and policy goals

  10. Dose limits cause unacceptable risk

    International Nuclear Information System (INIS)

    Collier, Sylvia.

    1985-01-01

    This paper on radiation dose limits for workers and the public discusses the following: Medical Research Council report; safety standards; risk assessment; deaths from cancers; biological radiation effects; UK legislation; low-level radiation; public concern; UKAEA staff survey; Ionising Radiations Regulations; United Nations Scientific Committee on Effects of Atomic Radiation; US studies on work force in nuclear establishments; problems of extrapolation; Japanese data from Hiroshima and Nagasaki; International Commission on Radiological Protection recommendations; studies on uranium miners; UK Health and Safety Executive; UK National Radiological Protection Board. (U.K.)

  11. Concentration - dose - risk computer code

    International Nuclear Information System (INIS)

    Frujinoiu, C.; Preda, M.

    1997-01-01

    Generally, the society is less willing in promoting remedial actions in case of low level chronic exposure situations. Radon in dwellings and workplaces is a case connected to chronic exposure. Apart from radon, the solely source on which the international community agreed for setting action levels, there are other numerous sources technically modified by man that can generate chronic exposure. Even if the nuclear installations are the most relevant, we are surrounded by 'man-made radioactivity' such as: mining industry, coal-fired power plants and fertilizer industry. The operating of an installation even within 'normal limits' could generate chronic exposure due to accumulation of the pollutants after a definite time. This asymptotic proclivity to a constant level define a steady-state concentration that represents a characteristic of the source's presence in the environment. The paper presents a methodology and a code package that derives sequentially the steady-state concentration, doses, detriments, as well as the costs of the effects of installation operation in a given environment. (authors)

  12. Radiation doses and risks from internal emitters

    International Nuclear Information System (INIS)

    Harrison, John; Day, Philip

    2008-01-01

    This review updates material prepared for the UK Government Committee Examining Radiation Risks from Internal Emitters (CERRIE) and also refers to the new recommendations of the International Commission on Radiological Protection (ICRP) and other recent developments. Two conclusions from CERRIE were that ICRP should clarify and elaborate its advice on the use of its dose quantities, equivalent and effective dose, and that more attention should be paid to uncertainties in dose and risk estimates and their implications. The new ICRP recommendations provide explanations of the calculation and intended purpose of the protection quantities, but further advice on their use would be helpful. The new recommendations refer to the importance of understanding uncertainties in estimates of dose and risk, although methods for doing this are not suggested. Dose coefficients (Sv per Bq intake) for the inhalation or ingestion of radionuclides are published as reference values without uncertainty. The primary purpose of equivalent and effective dose is to enable the summation of doses from different radionuclides and from external sources for comparison with dose limits, constraints and reference levels that relate to stochastic risks of whole-body radiation exposure. Doses are calculated using defined biokinetic and dosimetric models, including reference anatomical data for the organs and tissues of the human body. Radiation weighting factors are used to adjust for the different effectiveness of different radiation types, per unit absorbed dose (Gy), in causing stochastic effects at low doses and dose rates. Tissue weighting factors are used to take account of the contribution of individual organs and tissues to overall detriment from cancer and hereditary effects, providing a simple set of rounded values chosen on the basis of age- and sex-averaged values of relative detriment. While the definition of absorbed dose has the scientific rigour required of a basic physical quantity

  13. Patient dose and risk in mammography

    International Nuclear Information System (INIS)

    Law, J.

    1991-01-01

    Patient dose in mammography is estimated by two methods compared and giving agreement. A mean tissue dose of about 1 mGy per film is found for a breast of 4.5 cm compressed thickness. Variables affecting dose are then considered quantitatively, including compressed breast thickness, tube potential, grids, magnification and beam collimation. The variables having the greatest effect are breast thickness and magnification. The dose estimates are combined with existing data on breast cancer induction to predict the risk of carcinogenesis in a breast screening programme. For example, in a screening centre performing 15 000 examinations per year, only one induced cancer is predicted in about 7 years of screening under average UK conditions of age and breast thickness. (author)

  14. New risk estimates at low doses

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1992-01-01

    The age of molecular radiation epidemiology may be at hand. The techniques are available to establish with the degree of precision required to determine whether agent-specific mutations can be identified consistently. A concerted effort to examine radiation-induced changes in as many relevant genes as possible appears to be justified. Cancers in those exposed to low doses of ionizing radiation should be chosen for the investigation. Parallel studies of radiation-induced cancers in experimental animals would not only complement the human studies, but perhaps reveal approaches to extrapolation of risk estimates across species. A caveat should be added to this optimistic view of what molecular studies might contribute to the knotty problem of risk estimates at low doses. The suggestions are made by one with no expertise in the field of molecular biology

  15. Low-Dose Risk, Decisions, and Risk Communication

    International Nuclear Information System (INIS)

    Flynn, James; Slovic, Paul

    2001-01-01

    To conduct basic research on how people receive, evaluate, and form positions on scientific information and its relationship to low-dose radiation exposure. There are three major areas of study in our research program. First is the development of theories, frameworks and concepts essential to guiding data collection and analysis. The second area is a program of experimental studies on risk perception, evaluation of science information, and the structure of individual positions regarding low dose exposures. This involves the study of existing knowledge and the evaluation of science information presented within a variety of formats, as educational information, news media stories, and alternative communication methods (personal contact, small group interaction, email and internet, etc.). Third is the community-level studies to examine and record how the social conditions, under which science communications take place, influence the development of attitudes and opinions about: low- dose exposures, the available management options, control of radiation risks, and preferences for program and policy goals

  16. Volume dose of organs at risk in the irradiated volume

    International Nuclear Information System (INIS)

    Hishikawa, Yoshio; Tanaka, Shinichi; Miura, Takashi

    1984-01-01

    Absorbed dose of organs at risk in the 50% irradiated volume needs to be carefully monitored because there is high risk of radiation injury. This paper reports on the histogram of threedimensional volume dose of organs at risk, which is obtained by computer calculation of CT scans. In order to obtain this histogram, CT is first performed in the irradiation field. The dose in each pixel is then examined by the computer as to each slice. After the pixels of all slices in the organ at risk of the irradiated field are classified according to the doses, the number of pixels in the same dose class is counted. The result is expressed in a histogram. The histogram can show the differences of influence to organs at risk given by various radiation treatment techniques. Total volume dose of organs at risk after radiotherapy can also be obtained by integration of each dose of different treatment techniques. (author)

  17. Risk of cancer subsequent to low-dose radiation

    International Nuclear Information System (INIS)

    Warren, S.

    1980-01-01

    The author puts low dose irradiation risks in perspective using average background radiation doses for standards. He assailed irresponsible media coverage during the height of public interest in the Three-Mile Island Reactor incident

  18. Evaluation of effective dose and excess lifetime cancer risk from ...

    African Journals Online (AJOL)

    Evaluation of effective dose and excess lifetime cancer risk from indoor and outdoor gamma dose rate of university of Port Harcourt Teaching Hospital, Rivers State. ... Therefore, the management of University of Port Harcourt teaching hospital ...

  19. Excipient Usage Technical Risk Assessment for Generic Solid Dose Products

    Directory of Open Access Journals (Sweden)

    Ajay Babu Pazhayattil

    2017-09-01

    Full Text Available This paper proposes an assessment methodology for solid dose generic small molecule drug products. It addresses the ‘usage of the excipient’ portion of the trinomial by utilizing the systematic approach of Risk Identification, Risk Analysis and Risk Evaluation as per ICH Q9 Quality Risk Management outlined for developing risk control strategies. The assessment and maintenance of excipient risk profile is essential to minimize any potential risk associated to excipients impacting patients.

  20. Radiation dose and cancer risk to children undergoing skull radiography

    International Nuclear Information System (INIS)

    Mazonakis, Michael; Damilakis, John; Raissaki, Maria; Gourtsoyiannis, Nicholas

    2004-01-01

    Background: Limited data exist in the literature concerning the patient-effective dose from paediatric skull radiography. No information has been provided regarding organ doses, patient dose during PA skull projection, risk of cancer induction and dose to comforters, i.e. individuals supporting children during exposure. Objective: To estimate patient-effective dose, organ doses, lifetime cancer mortality risk to children and radiation dose to comforters associated with skull radiography. Materials and methods: Data were collected from 136 paediatric examinations, including AP, PA and lateral skull radiographs. Entrance-surface dose (ESD) and dose to comforters were measured using thermoluminescent dosimeters. Patients were divided into the following age groups: 0.5-2, 3-7, 8-12 and 13-18 years. The patient-effective dose and corresponding organ doses were calculated using data from the NRPB and Monte Carlo techniques. The risk for fatal cancer induction was assessed using appropriate risk coefficients. Results: For AP, PA and lateral skull radiography, effective dose ranges were 8.8-25.4, 8.2-27.3 and 8.4-22.7 μSv respectively, depending upon the age of the child. For each skull projection, the organs receiving doses above 10 μGy are presented. The number of fatal cancers was found to be less than or equal to 2 per 1 million children undergoing a skull radiograph. The mean radiation dose absorbed by the hands of comforters was 13.4 μGy. Conclusions: The current study provides detailed tabular and graphical data on ESD, effective dose, organ doses and lifetime cancer mortality risk to children associated with AP, PA and lateral skull projections at all patient ages. (orig.)

  1. Relationship between dose and risk, and assessment of carcinogenic risks associated with low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Tubiana, M.; Aurengo, A.

    2005-01-01

    This report raises doubts on the validity of using LNT (linear no-threshold) relationship for evaluating the carcinogenic risk of low doses (< 100 mSv) and even more for very low doses (< 10 mSv). The LNT concept can be a useful pragmatic tool for assessing rules in radioprotection for doses above 10 mSv; however since it is not based on biological concepts of our current knowledge, it should not be used without precaution for assessing by extrapolation the risks associated with low and even more so, with very low doses (< 10 mSv), especially for benefit-risk assessments imposed on radiologists by the European directive 97-43. The biological mechanisms are different for doses lower than a few dozen mSv and for higher doses. The eventual risks in the dose range of radiological examinations (0.1 to 5 mSv, up to 20 mSv for some examinations) must be estimated taking into account radiobiological and experimental data. An empirical relationship which has been just validated for doses higher than 200 mSv may lead to an overestimation of risks (associated with doses one hundred fold lower), and this overestimation could discourage patients from undergoing useful examinations and introduce a bias in radioprotection measures against very low doses (< 10 mSv). Decision makers confronted with problems of radioactive waste or risk of contamination, should re-examine the methodology used for the evaluation of risks associated with very low doses and with doses delivered at a very low dose rate. This report confirms the inappropriateness of the collective dose concept to evaluate population irradiation risks

  2. Estimation of radiation risks at low dose

    International Nuclear Information System (INIS)

    1990-04-01

    The report presents a review of the effects caused by radiation in low doses, or at low dose rates. For the inheritable (or ''genetic''), as well as for the cancer producing effects of radiation, present evidence is consistent with: (a) a non-linear relationship between the frequency of at least some forms of these effects, with comparing frequencies caused by doses many times those received annually from natural sources, with those caused by lower doses; (b) a probably linear relationship, however, between dose and frequency of effects for dose rates in the region of that received from natural sources, or at several times this rate; (c) no evidence to indicate the existence of a threshold dose below which such effects are not produced, and a strong inference from the mode of action of radiation on cells at low dose rates that no such thresholds are likely to apply to the detrimental, cancer-producing or inheritable, effects resulting from unrepaired damage to single cells. 19 refs

  3. We can do better than effective dose for estimating or comparing low-dose radiation risks

    International Nuclear Information System (INIS)

    Brenner, D.J.

    2012-01-01

    The effective dose concept was designed to compare the generic risks of exposure to different radiation fields. More commonly these days, it is used to estimate or compare radiation-induced cancer risks. For various reasons, effective dose represents flawed science: for instance, the tissue-specific weighting factors used to calculate effective dose are a subjective mix of different endpoints; and the marked and differing age and gender dependencies for different health detriment endpoints are not taken into account. This paper suggests that effective dose could be replaced with a new quantity, ‘effective risk’, which, like effective dose, is a weighted sum of equivalent doses to different tissues. Unlike effective dose, where the tissue-dependent weighting factors are a set of generic, subjective committee-defined numbers, the weighting factors for effective risk are simply evaluated tissue-specific lifetime cancer risks per unit equivalent dose. Effective risk, which has the potential to be age and gender specific if desired, would perform the same comparative role as effective dose, be just as easy to estimate, be less prone to misuse, be more directly understandable, and would be based on solid science. An added major advantage is that it gives the users some feel for the actual numerical values of the radiation risks they are trying to control.

  4. Nonparametric estimation of benchmark doses in environmental risk assessment

    Science.gov (United States)

    Piegorsch, Walter W.; Xiong, Hui; Bhattacharya, Rabi N.; Lin, Lizhen

    2013-01-01

    Summary An important statistical objective in environmental risk analysis is estimation of minimum exposure levels, called benchmark doses (BMDs), that induce a pre-specified benchmark response in a dose-response experiment. In such settings, representations of the risk are traditionally based on a parametric dose-response model. It is a well-known concern, however, that if the chosen parametric form is misspecified, inaccurate and possibly unsafe low-dose inferences can result. We apply a nonparametric approach for calculating benchmark doses, based on an isotonic regression method for dose-response estimation with quantal-response data (Bhattacharya and Kong, 2007). We determine the large-sample properties of the estimator, develop bootstrap-based confidence limits on the BMDs, and explore the confidence limits’ small-sample properties via a short simulation study. An example from cancer risk assessment illustrates the calculations. PMID:23914133

  5. Effective dose and cancer risk in PET/CT exams

    International Nuclear Information System (INIS)

    Pinto, Gabriella M.; Sa, Lidia Vasconcellos de

    2013-01-01

    Due to the use of radiopharmaceutical positron-emitting in PET exam and realization of tomography by x-ray transmission in CT examination, an increase of dose with hybrid PET/CT technology is expected. However, differences of doses have been reported in many countries for the same type of procedure. It is expected that the dose is an influent parameter to standardize the protocols of PET/CT. This study aimed to estimate the effective doses and absorbed in 65 patients submitted to oncological Protocol in a nuclear medicine clinic in Rio de Janeiro, considering the risk of induction of cancer from the scan. The CT exam-related doses were estimated with a simulator of PMMA and simulated on the lmPACT resistance, which for program effective dose, were considered the weight factors of the lCRP 103. The PET exam doses were estimated by multiplying the activity administered to the patient with the ICRP dose 80 factors. The radiological risk for cancer incidence were estimated according to the ICRP 103. The results showed that the effective dose from CT exam is responsible for 70% of the effective total in a PET/CT scan. values of effective dose for the PET/CT exam reached average values of up to 25 mSv leading to a risk of 2, 57 x 10 -4 . Considering that in staging of oncological diseases at least four tests are performed annually, the total risk comes to 1,03x 10 -3

  6. Dose dependence on stochastic radiobiological effect in radiation risk estimation

    International Nuclear Information System (INIS)

    Komochkov, M.M.

    1999-01-01

    The analysis of the results in dose -- effect relationship observation has been carried out on the cell and organism levels, with the aim to obtain more precise data on the risk coefficients at low doses. The results are represented by two contrasting groups of dose dependence on effect: a downwards concave and a J-shaped curve. Both types of dependence are described by the equation solutions of an assumed unified protective mechanism, which comprises two components: constitutive and adaptive or inducible ones. The latest data analysis of the downwards concave dependence curves shows a considerable underestimation of radiation risk in all types of cancer, except leukemia, for a number of critical groups in a population, at low doses comparing to the ICRP recommendations. With the dose increase, the decrease of the effect value per dose unit is observed. It may be possibly related to the switching of the activity of the adaptive protective mechanism, with some threshold dose values being exceeded

  7. The gamma knife: Dose and risk evaluation

    International Nuclear Information System (INIS)

    Jones, E.D.; Alesso, H.P.; Banks, W.W.; Rathbun, P.A.

    1992-01-01

    This paper outlines a risk analysis approach designed to identify and assess most likely failure modes and high-risk, human initiated actions for nuclear medical devices. This approach is being developed under the auspices of the US Nuclear Regulatory Commission, Office of Nuclear Material Safety and Safeguards. The methodology is initiated intended to assess risk associated with the use of the Leksell Gamma Unit (LGU) or gamma knife, a gamma stereotactic radiosurgical device

  8. Knowledge of medical imaging radiation dose and risk among doctors

    International Nuclear Information System (INIS)

    Brown, Nicholas; Jones, Lee

    2013-01-01

    The growth of computed tomography (CT) and nuclear medicine (NM) scans has revolutionised healthcare but also greatly increased population radiation doses. Overuse of diagnostic radiation is becoming a feature of medical practice, leading to possible unnecessary radiation exposures and lifetime-risks of developing cancer. Doctors across all medical specialties and experience levels were surveyed to determine their knowledge of radiation doses and potential risks associated with some diagnostic imaging. A survey relating to knowledge and understanding of medical imaging radiation was distributed to doctors at 14 major Queensland public hospitals, as well as fellows and trainees in radiology, emergency medicine and general practice. From 608 valid responses, only 17.3% correctly estimated the radiation dose from CT scans and almost 1 in 10 incorrectly believed that CT radiation is not associated with any increased lifetime risk of developing cancer. There is a strong inverse relationship between a clinician's experience and their knowledge of CT radiation dose and risks, even among radiologists. More than a third (35.7%) of doctors incorrectly believed that typical NM imaging either does not use ionising radiation or emits doses equal to or less than a standard chest radiograph. Knowledge of CT and NM radiation doses is poor across all specialties, and there is a significant inverse relationship between experience and awareness of CT dose and risk. Despite having a poor understanding of these concepts, most doctors claim to consider them prior to requesting scans and when discussing potential risks with patients.

  9. Radiation Dose Risk and Diagnostic Benefit in Imaging Investigations

    OpenAIRE

    Dobrescu, Lidia; Rădulescu, Gheorghe-Cristian

    2015-01-01

    The paper presents many facets of medical imaging investigations radiological risks. The total volume of prescribed medical investigations proves a serious lack in monitoring and tracking of the cumulative radiation doses in many health services. Modern radiological investigations equipment is continuously reducing the total dose of radiation due to improved technologies, so a decrease in per caput dose can be noticed, but the increasing number of investigations has determined a net increase ...

  10. Radiation risk factors and dose limits

    International Nuclear Information System (INIS)

    Barendsen, G.W.

    1979-01-01

    The contents of the ICRP publications 9 (1965) and 26 (1977) are outlined and the research conducted during these years considered. Expressions are derived for the frequency for induction of cancer from the most common irradiations - X rays, gamma rays and electrons. The dose limits advised by the ICRP are discussed and the first two fundamental principles are presented - that no one should be subjected to radiation without useful cause and that in those cases where irradiation is thought necessary, the medical, scientific, social and economic advantages need to be carefully considered with respect to the possible disadvantages. (C.F.)

  11. Multidisciplinary European Low Dose Initiative (MELODI). Strategic research agenda for low dose radiation risk research

    Energy Technology Data Exchange (ETDEWEB)

    Kreuzer, M. [Federal Office for Radiation Protection, BfS, Department of Radiation Protection and Health, Neuherberg (Germany); Auvinen, A. [University of Tampere, Tampere (Finland); STUK, Helsinki (Finland); Cardis, E. [ISGlobal, Barcelona Institute for Global Health, Barcelona (Spain); Durante, M. [Institute for Fundamental Physics and Applications, TIFPA, Trento (Italy); Harms-Ringdahl, M. [Stockholm University, Centre for Radiation Protection Research, Stockholm (Sweden); Jourdain, J.R. [Institute for Radiological Protection and Nuclear Safety, IRSN, Fontenay-aux-roses (France); Madas, B.G. [MTA Centre for Energy Research, Environmental Physics Department, Budapest (Hungary); Ottolenghi, A. [University of Pavia, Physics Department, Pavia (Italy); Pazzaglia, S. [Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Rome (Italy); Prise, K.M. [Queens University Belfast, Belfast (United Kingdom); Quintens, R. [Belgian Nuclear Research Centre, SCK-CEN, Mol (Belgium); Sabatier, L. [French Atomic Energy Commission, CEA, Paris (France); Bouffler, S. [Public Health England, PHE, Chilton (United Kingdom)

    2018-03-15

    MELODI (Multidisciplinary European Low Dose Initiative) is a European radiation protection research platform with focus on research on health risks after exposure to low-dose ionising radiation. It was founded in 2010 and currently includes 44 members from 18 countries. A major activity of MELODI is the continuous development of a long-term European Strategic Research Agenda (SRA) on low-dose risk for radiation protection. The SRA is intended to identify priorities for national and European radiation protection research programs as a basis for the preparation of competitive calls at the European level. Among those key priorities is the improvement of health risk estimates for exposures close to the dose limits for workers and to reference levels for the population in emergency situations. Another activity of MELODI is to ensure the availability of European key infrastructures for research activities, and the long-term maintenance of competences in radiation research via an integrated European approach for training and education. The MELODI SRA identifies three key research topics in low dose or low dose-rate radiation risk research: (1) dose and dose rate dependence of cancer risk, (2) radiation-induced non-cancer effects and (3) individual radiation sensitivity. The research required to improve the evidence base for each of the three key topics relates to three research lines: (1) research to improve understanding of the mechanisms contributing to radiogenic diseases, (2) epidemiological research to improve health risk evaluation of radiation exposure and (3) research to address the effects and risks associated with internal exposures, differing radiation qualities and inhomogeneous exposures. The full SRA and associated documents can be downloaded from the MELODI website (http://www.melodi-online.eu/sra.html). (orig.)

  12. Risk equivalent of exposure versus dose of radiation

    International Nuclear Information System (INIS)

    Bond, V.P.

    1986-01-01

    This report describes a risk analysis study of low-dose irradiation and the resulting biological effects on a cell. The author describes fundamental differences between the effects of high-level exposure (HLE) and low-level exposure (LLE). He stresses that the concept of absorbed dose to an organ is not a dose but a level of effect produced by a particular number of particles. He discusses the confusion between a linear-proportional representation of dose limits and a threshold-curvilinear representation, suggesting that a LLE is a composite of both systems

  13. Patient Doses and Risk Evaluation in Bone Mineral Densitometry

    International Nuclear Information System (INIS)

    Angelucci, M.; Borio, R.; Chiocchini, S.; Degli Esposti, P.; Dipilato, A.C.; Policani, G.

    1999-01-01

    The aim of this work was to evaluate the equipment dose to the organs and tissues and the effective dose of patients undergoing the most frequent examinations carried out in bone mineral densitometry (BMD): lumbar spine and femur. Experimental measurements of absorbed doses on a Rando phantom, allow comparison of the performances of three different photon emitter facilities. The comparison of the entrance and exit doses measured on a Rando phantom and on 50 female non-obese patients show that entrance doses on Rando can be used as 'diagnostic reference levels' for patients. A quantitative estimate of the stochastic risk due to BMD procedures was made: the results obtained show that the stochastic risk is very low and that the BMD is, at present, the most confirmed procedure for osteoporosis diagnosis and management. (author)

  14. Risks to health from radiation at low dose rates

    International Nuclear Information System (INIS)

    Gentner, N.E.; Osborne, R.V.

    1997-01-01

    Our focus is on whether, using a balance-of-evidence approach, it is possible to say that at a low enough dose, or at a sufficiently low dose rate, radiation risk reduces to zero in a population. We conclude that insufficient evidence exists at present to support such a conclusion. In part this reflects statistical limitations at low doses, and in part (although mechanisms unquestionably exist to protect us against much of the damage induced by ionizing radiation) the biological heterogeneity of human populations, which means these mechanisms do not act in all members of the population at all times. If it is going to be possible to demonstrate that low doses are less dangerous than we presently assume, the evidence, paradoxically, will likely come from studies of higher dose and dose rate scenarios than are encountered occupationally. (author)

  15. Cancer risk of low dose/low dose rate radiation: a meta-analysis of cancer data of mammals exposed to low doses of radiation

    International Nuclear Information System (INIS)

    Ogata, Hiromitsu; Magae, Junji

    2008-01-01

    Full text: Linear No Threshold (LNT) model is a basic theory for radioprotection, but the adaptability of this hypothesis to biological responses at low doses or at low dose rates is not sufficiently investigated. Simultaneous consideration of the cumulative dose and the dose rate is necessary for evaluating the risk of long-term exposure to ionizing radiation at low dose. This study intends to examine several numerical relationships between doses and dose rates in biological responses to gamma radiation. Collected datasets on the relationship between dose and the incidence of cancer in mammals exposed to low doses of radiation were analysed using meta-regression models and modified exponential (MOE) model, which we previously published, that predicts irradiation time-dependent biological response at low dose rate ionizing radiation. Minimum doses of observable risk and effective doses with a variety of dose rates were calculated using parameters estimated by fitting meta-regression models to the data and compared them with other statistical models that find values corresponding to 'threshold limits'. By fitting a weighted regression model (fixed-effects meta-regression model) to the data on risk of all cancers, it was found that the log relative risk [log(RR)] increased as the total exposure dose increased. The intersection of this regression line with the x-axis denotes the minimum dose of observable risk. These estimated minimum doses and effective doses increased with decrease of dose rate. The goodness of fits of MOE-model depended on cancer types, but the total cancer risk is reduced when dose rates are very low. The results suggest that dose response curve for cancer risk is remarkably affected by dose rate and that dose rate effect changes as a function of dose rate. For scientific discussion on the low dose exposure risk and its uncertainty, the term 'threshold' should be statistically defined, and dose rate effects should be included in the risk

  16. Hiroshima and Nagasaki: New doses, risks, and their implications

    International Nuclear Information System (INIS)

    Schull, W.J.; Shimizu, Y.; Kato, H.

    1990-01-01

    This presentation summarizes the recent re-evaluations of the dose and risk of cancer among survivors of the atomic bombing of Hiroshima and Nagasaki. It addresses briefly their limitations, and describes some of their implications for the lifetime projection of the risk of a fatal cancer following exposure to ionizing radiation

  17. Collective effective dose equivalent, population doses and risk estimates from occupational exposures in Japan

    International Nuclear Information System (INIS)

    Maruyama, Takashi; Nishizawa, Kanae; Kumamoto, Yoshikazu; Iwai, Kazuo; Mase, Naomichi.

    1993-01-01

    Collective dose equivalent and population dose from occupational exposures in Japan, 1988 were estimated on the basis of a nationwide survey. The survey was conducted on annual collective dose equivalents by sex, age group and type of radiation work for about 0.21 million workers except for the workers in nuclear power stations. The data on the workers in nuclear power stations were obtained from the official report of the Japan Nuclear Safety Commission. The total number of workers including nuclear power stations was estimated to be about 0.26 million. Radiation works were subdivided as follows: medical works including dental; non-atomic energy industry; research and education; atomic energy industry and nuclear power station. For the determination of effective dose equivalent and population dose, organ or tissue doses were measured with a phantom experiment. The resultant doses were compared with the doses previously calculated using a chord length technique and with data from ICRP publications. The annual collective effective dose equivalent were estimated to be about 21.94 person·Sv for medical workers, 7.73 person·Sv for industrial workers, 0.75 person·Sv for research and educational workers, 2.48 person·Sv for atomic energy industry and 84.4 person ·Sv for workers in nuclear power station. The population doses were calculated to be about 1.07 Sv for genetically significant dose, 0.89 Sv for leukemia significant dose and 0.42 Sv for malignant significant dose. The population risks were estimated using these population doses. (author)

  18. On possible risks of low-dose irradiation

    International Nuclear Information System (INIS)

    Hug, O.; Gesellschaft fuer Strahlen- und Umweltforschung m.b.H., Neuherberg/Muenchen

    1974-01-01

    The survey on more recent experimental and epidemiological data and newer concepts for a realistic estimation of the radiation risk leads to the conclusion that for radiation late damages and possibly also for genetic damages with a chronical radiation exposure in the order of magnitude of the natural radiation exposure and probably also in the order of magnitude of the maximum permissible radiation dose, the risk is very probably lower than is to be expected based on the findings after relatively high doses and dose rates. A few less direct comparative studies have detected a time factor of 3 to 5. Considering the analysis of the RBW demely ionizing radiation which at high doses is not greater than 3, increases with decreasing dose and according to biophysical considerations, can possibly reach a value of 30, an effectiveness reduced by a factor of 10 of small doses and dose rates of loosely ionizing radiation would be even to be expected. All radiobiological knowledge on the effect of ionizing radiation allows one to expect that even smallest radiation doses can cause cellular damages due to the linear irreversable components of the radiation effect and probably that these damages can even be the starting point of a malignant tumour. Regarding this cancer-initiating effect however, the effectiveness of loosely ionizing radiation per rad in the region of natural radiation exposure lie considerably below that existing at high doses and dose rates. Whether however this initial carcinogenic effect of very small doses is at all noticeable during the average life duration in an increase of the spontaneous age-specific tumour rate is questionable if the assumption is confirmed that with decreasing dose, the time manifestation of the radiation induced tumours is delayed. (orig./LH) [de

  19. Knowledge of medical imaging radiation dose and risk among doctors.

    Science.gov (United States)

    Brown, Nicholas; Jones, Lee

    2013-02-01

    The growth of computed tomography (CT) and nuclear medicine (NM) scans has revolutionised healthcare but also greatly increased population radiation doses. Overuse of diagnostic radiation is becoming a feature of medical practice, leading to possible unnecessary radiation exposures and lifetime-risks of developing cancer. Doctors across all medical specialties and experience levels were surveyed to determine their knowledge of radiation doses and potential risks associated with some diagnostic imaging. A survey relating to knowledge and understanding of medical imaging radiation was distributed to doctors at 14 major Queensland public hospitals, as well as fellows and trainees in radiology, emergency medicine and general practice. From 608 valid responses, only 17.3% correctly estimated the radiation dose from CT scans and almost 1 in 10 incorrectly believed that CT radiation is not associated with any increased lifetime risk of developing cancer. There is a strong inverse relationship between a clinician's experience and their knowledge of CT radiation dose and risks, even among radiologists. More than a third (35.7%) of doctors incorrectly believed that typical NM imaging either does not use ionising radiation or emits doses equal to or less than a standard chest radiograph. Knowledge of CT and NM radiation doses is poor across all specialties, and there is a significant inverse relationship between experience and awareness of CT dose and risk. Despite having a poor understanding of these concepts, most doctors claim to consider them prior to requesting scans and when discussing potential risks with patients. © 2012 The Authors. Journal of Medical Imaging and Radiation Oncology © 2012 The Royal Australian and New Zealand College of Radiologists.

  20. Radiation Dose-Response Relationships and Risk Assessment

    International Nuclear Information System (INIS)

    Strom, Daniel J.

    2005-01-01

    The notion of a dose-response relationship was probably invented shortly after the discovery of poisons, the invention of alcoholic beverages, and the bringing of fire into a confined space in the forgotten depths of ancient prehistory. The amount of poison or medicine ingested can easily be observed to affect the behavior, health, or sickness outcome. Threshold effects, such as death, could be easily understood for intoxicants, medicine, and poisons. As Paracelsus (1493-1541), the 'father' of modern toxicology said, 'It is the dose that makes the poison.' Perhaps less obvious is the fact that implicit in such dose-response relationships is also the notion of dose rate. Usually, the dose is administered fairly acutely, in a single injection, pill, or swallow; a few puffs on a pipe; or a meal of eating or drinking. The same amount of intoxicants, medicine, or poisons administered over a week or month might have little or no observable effect. Thus, before the discovery of ionizing radiation in the late 19th century, toxicology ('the science of poisons') and pharmacology had deeply ingrained notions of dose-response relationships. This chapter demonstrates that the notion of a dose-response relationship for ionizing radiation is hopelessly simplistic from a scientific standpoint. While useful from a policy or regulatory standpoint, dose-response relationships cannot possibly convey enough information to describe the problem from a quantitative view of radiation biology, nor can they address societal values. Three sections of this chapter address the concepts, observations, and theories that contribute to the scientific input to the practice of managing risks from exposure to ionizing radiation. The presentation begins with irradiation regimes, followed by responses to high and low doses of ionizing radiation, and a discussion of how all of this can inform radiation risk management. The knowledge that is really needed for prediction of individual risk is presented

  1. Correlation between effective dose and radiological risk: general concepts

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Paulo Roberto; Yoshimura, Elisabeth Mateus; Nersissian, Denise Yanikian; Melo, Camila Souza, E-mail: pcosta@if.usp.br [Universidade de Sao Paulo (IF/USP), Sao Paulo, SP (Brazil). Instituto de Fisica

    2016-05-15

    The present review aims to offer an educational approach related to the limitations in the use of the effective dose magnitude as a tool for the quantification of doses resulting from diagnostic applications of ionizing radiation. We present a critical analysis of the quantities accepted and currently used for dosimetric evaluation in diagnostic imaging procedures, based on studies published in the literature. It is highlighted the use of these quantities to evaluate the risk attributed to the procedure and to calculate the effective dose, as well as to determine its correct use and interpretation. (author)

  2. A comparison of dose versus risk at environmental restoration sites

    International Nuclear Information System (INIS)

    Holm-Hansen, T.; Pastor, R.S.

    1996-01-01

    This paper compares current US Environmental Protection Agency methods for completing risk assessments at radionuclide-contaminated sites with the International Council for Radiation Protection dose-based method. The two methods produce inconsistent results that could complicate cleanup decisions. Important issues include uncertainties associated with the use of carcinogenic slope factors and methods to account for institutional controls and decay of the source term for decision-making purposes. Overall, risk management at sites contaminated with radionuclides should be driven by a dose-based approach through adoption of the proposed 15 millirem cleanup standard found in Title 40 Code of Federal Regulations, Part 191

  3. Dermatologic radiotherapy and thyroid cancer. Dose measurements and risk quantification

    International Nuclear Information System (INIS)

    Goldschmidt, H.; Gorson, R.O.; Lassen, M.

    1983-01-01

    Thyroid doses for various dermatologic radiation techniques were measured with thermoluminescent dosimeters and ionization rate meters in an Alderson-Rando anthropomorphic phantom. The effects of changes in radiation quality and of the use or nonuse of treatment cones and thyroid shields were evaluated in detail. The results indicate that the potential risk of radiogenic thyroid cancer is very small when proper radiation protection measures are used. The probability of radiogenic thyroid cancer developing and the potential mortality risk were assessed quantitatively for each measurement. The quantification of radiation risks allows comparisons with risks of other therapeutic modalities and the common hazards of daily life

  4. Dose-stress synergism in cancer risk assessment

    International Nuclear Information System (INIS)

    Pop-Jordanova, N.; Pop-Jordanov, J.

    2001-01-01

    Our hypothesis is that the relatively low risk of cancer or leukaemia from depleted uranium, as predicted by the World Health Organization and the International Atomic Energy Agency, is a result of neglecting the synergism between physico-chemical agents and psychological stress agents (here shortly denoted as dose-stress synergism). We use the modified risk assessment model that comprises a psycho-somatic extension, originally developed by us for assessing the risks of energy sources. Our preliminary meta-analysis of animal and human studies on cancers confirmed the existence of stress effects, including the amplifying synergism. Consequently, the psychological stress can increase the probability of even small toxic chemical or ionizing radiation exposure to produce malignancy. Such dose-stress synergism might influence the health risks among military personnel and the residents in the highly stressful environment in the Balkans. Further investigation is needed to estimate the order of magnitude of these combined effects in particular circumstances. (Original)

  5. Review of European research trends of low dose radiation risk

    International Nuclear Information System (INIS)

    Iwasaki, Toshiyasu; Yoshida, Kazuo

    2010-01-01

    Large research projects on low dose radiation effects in Europe and US over the past decade have provided limited scientific knowledge which could underpin the validation of radiation protection systems. Recently in Europe, there have been repeated discussions and dialogues to improve the situation, and as the consequence, the circumstances surrounding low dose radiation risks are changing. In 2009, Multidisciplinary European Low Dose Initiative (MELODI) was established as a trans-national organization capable of ensuring appropriate governance of research in the pursuit of a long term shared vision, and Low Dose Research towards Multidisciplinary Integration (DoReMi) network was launched in 2010 to achieve fairly short term results in order to prove the validity of the MELODI approach. It is expected to be very effective and powerful activities to facilitate the reduction of uncertainties in the understanding of low dose risks, but the regulatory requests rushing the reinforcement of radiological protection regulations based on the precautional principles are more increasing. To develop reasonable radiological protection systems based on scientific evidences, we need to accelerate to collect scientific evidences which could directly underpin more appropriate radiation protection systems even in Japan. For the purpose, we Japan need to develop from an independent standpoint and share as a multidisciplinary vision a long term and holistic research strategy which enables to enhance Japanese advantages such as low dose rate facilities and animal facilities, as soon as possible. (author)

  6. Risks and radiation doses due to residential radon in Germany

    International Nuclear Information System (INIS)

    Beck, T.R.

    2017-01-01

    The population-averaged risk rate and the annual average effective dose due to residential radon in Germany were calculated. The calculations were based on an epidemiological approach taking into account the age- and gender-specific lung cancer incidence rates for the German population and the excess relative risk of 0.16 per 100 Bq.m"-"3 for residential radon. In addition, the risk estimates adjusted for the smoking habits were determined. The population-averaged risk rate for the whole population was estimated with 4.1.10"-"5 y"-"1 (95% confidence interval (CI) 1.4.10"-"5 - 7.6.10"-"5 y"-"1). Residential radon causes a detriment per year of 3.3.10"-"5 y"-"1 (95% CI 1.1.10"-"5 - 6.0.10"-"5 y"-"1), which corresponds to an annual average effective dose of 0.6 mSv (95% CI 0.2-1.1 mSv). Annually, ∼3400 lung cancer incidences are attributed to residential radon. The results from the epidemiological approach exercised in this study are considerably lower than the effective dose, which would be obtained from the dose conversion coefficient calculated using biokinetic and dosimetric models. (author)

  7. Equivalent dose, effective dose and risk assessment from cephalometric radiography to critical organs

    International Nuclear Information System (INIS)

    Kang, Seong Sook; Cho, Bon Hae; Kim, Hyun Ja

    1995-01-01

    In head and neck region, the critical organ and tissue doses were determined, and the risks were estimated from lateral, posteroanterial and basilar cephalometric radiography. For each cephalometric radiography, 31 TLDs were placed in selected sites (18 internal and 13 external sites) in a tissue-equivalent phantom and exposed, then read-out in the TLD reader. The following results were obtained; 1. From lateral cephalometric radiography, the highest effective dose recorded was that delivered to the salivary gland (3.6 μSv) and the next highest dose was that received by the bone marrow (3 μSv). 2. From posteroanterial cephalometric radiography, the highest effective dose recorded was that delivered to the salivary gland (2 μSv) and the next highest dose was that received by the bone marrow (1.8 μSv). 3. From basilar cephalometric radiography, the highest effective dose recorded was that delivered to the thyroid gland (31.4 μSv) and the next highest dose was that received by the salivary gland (13.3 μSv). 4. The probabilities of stochastic effect from lateral, posteroanterial and basilar cephalometric radiography were 0.72 X 10 -6 , 0.49 X 10 -6 and 3.51 X 10 -6 , respectively.

  8. Revision of risk estimates and implications for dose limits

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1989-01-01

    It has been apparent for some time that our estimates of the risks associated with exposure to ionizing radiation must be increased above those values reported by UNSCEAR in 1977 an dused by ICRP to form their present recommendations. NRPB foresaw some of these changes and introduced interim advice within the UK to restrict exposures of wordkers and members of the public to levels below the existing limits. Since that advice was given, UNSCEAR has produced a 1988 report reviewing human data to provide new estimates of risks associated with exposure at high doses and high doserates. These risk figures are up to 4 times higher than when UNSCEAR reported in 1977. In this paper, the reasons for the changes in the estimates of risk will be described and the current NRPB guidelines for risk factors for protection purposes will be presented. The implications of these new risk factors for the setting of dose limits will then be discussed. (Author). 10 refs.; 2 tabs

  9. The stochastic risks of radioactive radiation - risk assessment, risk proportions, dose limits

    International Nuclear Information System (INIS)

    Lindackers, K.H.

    1990-01-01

    The latest data on the delayed injury to the a-bomb survivors of Hiroshima and Nagasaki reveal that the effects of radiation are more severe than was estimated in the past. However, the application of these data to small dose rate radiation exposure over longer periods of time leads to an overestimation of the actual risk. The future supersonic aviation schemes for altitudes within 20,000 m should include early personnel check-ups for assessment of the required protective measures. (orig./DG) [de

  10. On the genetic risk after high dose radioiodine therapy with regard to the gonadal dose

    International Nuclear Information System (INIS)

    Ehrenheim, C.; Hauswirth, C.; Fitschen, J.; Martin, E.; Oetting, G.; Hundeshagen, H.

    1997-01-01

    Aim: The genetic risk for the offspring of patients treated with high doses of radioiodine was to be assessed with special regard to the gonadal dose caused by diagnostic and therapeutic procedures. Methods: 41 young females (aged between 19 and 39 years) and four young males (aged 26 to 36 years) treated with radioiodine because of a thyroid carcinoma were interviewed by use of a questionnaire. The course of pregnancy and birth history could be documented as well as the congenital and developmental conditions of 56 children. Results: The amount of radioactivity applied for therapy and whole body scans ranged over 4,144 and 35,15 GBq I-131; the individual gonadal dose was calculated based on the MIRD model and ranged over 0,2 and 2,2 Sv (0,51 Sv at a mean). The period of time between the last radioiodine application and confinement was at least 9 months, not exceeding 14 years. As to the course of pregnancy and birth two early abortions, one extrauterine gravidity and one premature birth due to an insufficiency of the placenta were stated. In one case a chromosomal translocation 7/14 occured as a genetic defect which lead to an interruption. The children's development was unconspicuous except of two cases of neurodermatitis as well as multiple allergies and an early closure of the anterior fontanelle in one child each. Conclusion: Although the genetic risk is supposed to increase with the gonadal dose achieved (doubling dose 1 Sv) and the increased risk of any congenital anomaly was calculated as about 13% at a mean in our patients, the rate of genetic determined diseases was not elevated (1,8% or 1/57). Thus, no increase of genetic defects or congenital malformations was reported in a total of 408 children described in the literature and in our group. (orig.) [de

  11. Determination of dose equivalent and risk in thorium cycle

    International Nuclear Information System (INIS)

    Ney, C.L.V.N.

    1988-01-01

    In these report are presented the calculations of dose equivalent and risk, utilizing the dosimetric model described in publication 30 of the International Comission on Radiological Protection. This information was obtained by the workers of the thorium cycle, employed at the Praia and Santo Amaro Facilities, by assessing the quantity and concentration of thorium in the air. The samples and the number of measurements were established through design of experiments techniques, and the results were evaluated with the aid of variance analysis. The estimater of dose equivalent for internal and external radiation exposure and risk associated were compared with the maximum recommended limits. The results indicate the existence of operation areas whose values were above those limits, requiring so an improvement in the procedures and services in order to meet the requirements of the radiological protetion. (author) [pt

  12. Risks, radiation dose and image quality of mammography

    International Nuclear Information System (INIS)

    Menges, V.

    1979-01-01

    For some time to come, early detection of breast cancer will remain the only way to improve the therapeutical success. Mammography is an absolutely indispensible way to take advantage of this opportunity. Today, mammography is undoubtedly the most reliable method of examination for an early detection of breast cancer. Only mammography can detect carcinomas smaller than the critical tumour size of 1cm. If carried out properly and with present dose levels, it involves hardly any radiation risk. (orig.) [de

  13. Current estimates of radiation risks and implications for dose limits

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1989-01-01

    The publication of the 1988 report of UNSCEAR represents a major step forward in that there is an international consensus on the estimation of risk from exposure to ionising radiation. The estimates of fatal cancers in the UNSCEAR report are up to 4 times the values in the 1977 review. This paper will describe the reasons for the increase, the remaining uncertainties and the implications for dose limits in occupational and public exposure. (author)

  14. Cancer risk from low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Auvinen, A.

    1997-06-01

    The aim of the study was to estimate cancer risk from small doses of ionizing radiation from various sources, including both external and internal exposure. The types of radiation included alpha, gamma, and neutron radiation. A nationwide follow-up study covering the years up to 1992 revealed no significant association between fallout from the Chernobyl accident and incidence of childhood leukemia. An excess of eight cases or more per year could be excluded. However, some indication of an increase was evident in the most heavily affected areas. Furthermore, the risk estimates were in accordance with those reported from Hiroshima and Nagasaki, although the confidence intervals were wide. (282 refs.)

  15. Cancer risk from low doses of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Auvinen, A

    1997-06-01

    The aim of the study was to estimate cancer risk from small doses of ionizing radiation from various sources, including both external and internal exposure. The types of radiation included alpha, gamma, and neutron radiation. A nationwide follow-up study covering the years up to 1992 revealed no significant association between fallout from the Chernobyl accident and incidence of childhood leukemia. An excess of eight cases or more per year could be excluded. However, some indication of an increase was evident in the most heavily affected areas. Furthermore, the risk estimates were in accordance with those reported from Hiroshima and Nagasaki, although the confidence intervals were wide. (282 refs.).

  16. Total Risk Management for Low Dose Radiation Exposures

    International Nuclear Information System (INIS)

    Simic, Z.; Mikulicic, V.; Sterc, D.

    2012-01-01

    Our civilization is witnessing about century of nuclear age mixed with enormous promises and cataclysmic threats. Nuclear energy seems to encapsulate both potential for pure good and evil or at least we humans are able to perceive that. These images are continuously with us and they are both helping and distracting from making best of nuclear potentials for civilization. Today with nuclear use significantly present and with huge potential to further improve our life with energy and medical use it is of enormous importance to try to have calmed, rational, and objective view on potential risks and certain benefits. Because all use of nuclear energy proved that their immediate risks are negligible (i.e., Three Mile Island and Fukushima) or much smaller than from the other alternatives (i.e., Chernobyl) it seems that the most important issue is the amount of risk from the long term effects to people from exposure to small doses of radiation. A similar issue is present in the increased use of modern computational tomography and other radiation sources use in medicine for examination and therapy. Finally, extreme natural exposures are third such potential risk sources. Definition of low doses varies depending on the way of delivery (i.e., single, multiple or continuous exposures), and for this paper usual dose of 100 mSv is selected as yearly upper amount. There are three very different scientifically supported views on the potential risks from the low doses exposure. The most conservative theory is that all radiation is harmful, and even small increments from background levels (i.e., 2-3 mSv) present additional risk. This view is called linear no threshold theory (LNT) and it is accepted as a regulatory conservative simple approach which guarantees safety. Risk is derived from the extrapolation of the measured effects of high levels of radiation. Opposite theory to LNT is hormesis which assumes that in fact small doses of radiation are helpful and they are improving our

  17. Epistemological problems in assessing cancer risks at low radiation doses

    International Nuclear Information System (INIS)

    Walinder, G.

    1987-01-01

    Historically, biology has not been subjected to any epistemological analysis as has been the case with mathematics and physics. Our knowledge of the effects in biological systems of various stimuli proves to be dualistic in a complementary (although not mutually exclusive) way, which bears resemblance to the knowledge of phenomena in quantum physics. The dualistic limbs of biological knowledge are the action of stimuli and the response of the exposed, biological system. With regard to radiogenic cancer, this corresponds to the action of the ionizations and the response of the exposed mammal to that action, respectively. The following conclusions can be drawn from the present analysis: Predictions as to radiogenic cancer seem often if not always to have neglected the response variability (variations in radiosensitivity) in individuals or among individuals in populations, i.e. the predictions have been based exclusively on radiation doses and exposure conditions. The exposed individual or population, however, must be considered an open statistical system, i.e. a system in which predictions as to the effect of an agent are only conditionally possible. The knowledge is inverse to the size of the dose or concentration of the active agent. On epistemological grounds, we can not gain knowledge about the carcinogenic capacity of very low (non-dominant) radiation doses. Based on the same principle, we can not predict cancer risks at very low (non-dominant) radiation doses merely on the basis of models, or otherwise interpolated or extrapolated high-dose effects, observed under special exposure conditions

  18. Risk and dose assessment methods in gamma knife QA

    International Nuclear Information System (INIS)

    Banks, W.W.; Jones, E.D.; Rathbun, P.

    1992-10-01

    Traditional methods used in assessing risk in nuclear power plants may be inappropriate to use in assessing medical radiation risks. The typical philosophy used in assessing nuclear reactor risks is machine dominated with only secondary attention paid to the human component, and only after critical machine failure events have been identified. In assessing the risk of a misadministrative radiation dose to patients, the primary source of failures seems to stem overwhelmingly, from the actions of people and only secondarily from machine mode failures. In essence, certain medical misadministrations are dominated by human events not machine failures. Radiological medical devices such as the Leksell Gamma Knife are very simple in design, have few moving parts, and are relatively free from the risks of wear when compared with a nuclear power plant. Since there are major technical differences between a gamma knife and a nuclear power plant, one must select a particular risk assessment method which is sensitive to these system differences and tailored to the unique medical aspects of the phenomena under study. These differences also generate major shifts in the philosophy and assumptions which drive the risk assessment (Machine-centered vs Person-centered) method. We were prompted by these basic differences to develop a person-centered approach to risk assessment which would reflect these basic philosophical and technological differences, have the necessary resolution in its metrics, and be highly reliable (repeatable). The risk approach chosen by the Livermore investigative team has been called the ''Relative Risk Profile Method'' and has been described in detail by Banks and Paramore, (1983)

  19. CANCER RISKS ATTRIBUTABLE TO LOW DOSES OF IONIZING RADIATION - ASSESSING WHAT WE REALLY KNOW?

    Science.gov (United States)

    Cancer Risks Attributable to Low Doses of Ionizing Radiation - What Do We Really Know?AbstractHigh doses of ionizing radiation clearly produce deleterious consequences in humans including, but not exclusively, cancer induction. At very low radiation doses the situatio...

  20. Dose and risk evaluation in digital mammography using computer modeling

    International Nuclear Information System (INIS)

    Correa, Samanda Cristine Arruda; Souza, Edmilson Monteiro de; Silva, Humberto de Oliveira; Silva, Ademir Xavier da; Lopes, Ricardo Tadeu; Magalhaes, Sarah Braga

    2010-01-01

    Digital mammography has been introduced in several countries in the last years. The new technology requires new optimising methods considering for instance the increased possibility of changing the absorbed dose, mainly in modern mammographic systems that allow the operator to choose the beam quality by varying the tube voltage, and filter and target materials. In this work, the Monte Carlo code MCNPX is used in order to investigate how the average glandular dose vary with tube voltage (23-32 kV) and anode-filter combination (Mo-Mo,Mo-Rh and Rh-Rh) in digital mammographic examinations. Furthermore, the risk of breast cancer incidence attributable to mammography exams was estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The results show that the risk of breast cancer incidence in women younger than 30 years of age tends to decrease significantly using Rh-Rh anode-filter combination and higher tube voltage. For women older than 50 years of age the variation of tube voltage, and anode-filter combination did not influence the risk values considerably. (author)

  1. Dose and risk evaluation in digital mammography using computer modeling

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Samanda Cristine Arruda; Souza, Edmilson Monteiro de, E-mail: scorrea@nuclear.ufrj.b, E-mail: emonteiro@nuclear.ufrj.b [Centro Universitario Estadual da Zona Oeste (CCMAT/UEZO), Rio de Janeiro, RJ (Brazil); Silva, Humberto de Oliveira, E-mail: hbetorj@gmail.co [Universidade Federal do Rio de Janeiro IF/UFRJ, RJ (Brazil). Inst. de Fisica; Silva, Ademir Xavier da; Lopes, Ricardo Tadeu; Magalhaes, Sarah Braga, E-mail: ademir@nuclear.ufrj.b, E-mail: ricardo@lin.ufrj.b, E-mail: smagalhaes@nuclear.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear

    2010-07-01

    Digital mammography has been introduced in several countries in the last years. The new technology requires new optimising methods considering for instance the increased possibility of changing the absorbed dose, mainly in modern mammographic systems that allow the operator to choose the beam quality by varying the tube voltage, and filter and target materials. In this work, the Monte Carlo code MCNPX is used in order to investigate how the average glandular dose vary with tube voltage (23-32 kV) and anode-filter combination (Mo-Mo,Mo-Rh and Rh-Rh) in digital mammographic examinations. Furthermore, the risk of breast cancer incidence attributable to mammography exams was estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The results show that the risk of breast cancer incidence in women younger than 30 years of age tends to decrease significantly using Rh-Rh anode-filter combination and higher tube voltage. For women older than 50 years of age the variation of tube voltage, and anode-filter combination did not influence the risk values considerably. (author)

  2. Low Dose Radiation Cancer Risks: Epidemiological and Toxicological Models

    Energy Technology Data Exchange (ETDEWEB)

    David G. Hoel, PhD

    2012-04-19

    The basic purpose of this one year research grant was to extend the two stage clonal expansion model (TSCE) of carcinogenesis to exposures other than the usual single acute exposure. The two-stage clonal expansion model of carcinogenesis incorporates the biological process of carcinogenesis, which involves two mutations and the clonal proliferation of the intermediate cells, in a stochastic, mathematical way. The current TSCE model serves a general purpose of acute exposure models but requires numerical computation of both the survival and hazard functions. The primary objective of this research project was to develop the analytical expressions for the survival function and the hazard function of the occurrence of the first cancer cell for acute, continuous and multiple exposure cases within the framework of the piece-wise constant parameter two-stage clonal expansion model of carcinogenesis. For acute exposure and multiple exposures of acute series, it is either only allowed to have the first mutation rate vary with the dose, or to have all the parameters be dose dependent; for multiple exposures of continuous exposures, all the parameters are allowed to vary with the dose. With these analytical functions, it becomes easy to evaluate the risks of cancer and allows one to deal with the various exposure patterns in cancer risk assessment. A second objective was to apply the TSCE model with varing continuous exposures from the cancer studies of inhaled plutonium in beagle dogs. Using step functions to estimate the retention functions of the pulmonary exposure of plutonium the multiple exposure versions of the TSCE model was to be used to estimate the beagle dog lung cancer risks. The mathematical equations of the multiple exposure versions of the TSCE model were developed. A draft manuscript which is attached provides the results of this mathematical work. The application work using the beagle dog data from plutonium exposure has not been completed due to the fact

  3. Radiation dose and risk in gastrointestinal roentgendiagnostic of the child

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, H; Loehr, H; Wallbaum, F [Hamburg Univ. (Germany, F.R.). Abt. fuer Roentgendiagnostik

    1978-11-01

    In gastrointestinal roentgendiagnostic of the child the exposure of the skin and the testis depends on body height and body weight. The dose grows with the age. The squaredose product (Rcm/sup 2/) and the energy absorbed by the body(integraldose, rdkg)increases comparably. On the other hand the quotient integraldosis/body weight is similar for the different age-groups. The radiation risk (the probability to die as consequence of a roentgenray induced disease) is approximately 1:100,000 to 1:10,000,000.

  4. Re-distribution of brachytherapy dose using a differential dose prescription adapted to risk of local failure in low-risk prostate cancer patients

    DEFF Research Database (Denmark)

    Rylander, Susanne; Polders, Daniel; Steggerda, Marcel J

    2015-01-01

    BACKGROUND AND PURPOSE: We investigated the application of a differential target- and dose prescription concept for low-dose-rate prostate brachytherapy (LDR-BT), involving a re-distribution of dose according to risk of local failure and treatment-related morbidity. MATERIAL AND METHODS: Our study......- and dose prescription concept of prescribing a lower dose to the whole gland and an escalated dose to the GTV using LDR-BT seed planning was technically feasible and resulted in a significant dose-reduction to urethra and bladder neck....

  5. Patient absorbed dose and radiation risk in nuclear medicine

    International Nuclear Information System (INIS)

    Hetherington, E.; Cochrane, P.

    1992-01-01

    Since the introduction of technetium-99m labelled radiopharmaceuticals used as imaging agents in the nuclear medicine departments of Australian hospitals, patients have voiced concern about the effect of having radioactive materials injected into their bodies. The danger of X-ray exposure is widely known and well accepted, as is exposure to ultrasound, computed tomography scans and other imaging techniques. However, radioactivity is an unknown, and fear of the unknown can occasionally lead to patients refusing to undergo a nuclear medicine procedure. The authors emphasised that the radiation dose to a patient from a typical procedure would depend on the patient's medical history and treatment; the average dose being approximately 50 times the exposure received from the natural environmental background radiation. Furthermore, over an extended period the body can repair most minor damage caused by radiation, just as the body can repair the damage caused by sunburn resulting from too much exposure to sunlight. The risk of genetic effects as a result of a medical radiation dose is than very small

  6. Risk at Low Doses: Scientific knowledge, uncertainties and management

    International Nuclear Information System (INIS)

    Giusssani, A.; Ballarini, F.; Ottolenghi, A.

    2002-01-01

    Most of the applications of ionizing radiation in the medical field, for the exposed workers as well as the majority of patients undergoing diagnostic examinations, can be seen as low situations. Epidemiological information is however available for dose and dose rates higher than the values typical of most medical situation. Main source of information is the Life Span Study (LSS) of Japanese. A-bomb survivors, supplemented by studies of selected groups of exposed workers (uranium miners, radium painters) or radiotherapy patients with a detailed follow-up history. All of these group studies, however, suffer from one or more of the following limitations: - lack of adequate dosimetry - lack of a reliable control group for the necessary comparison - influence of concomitant factors (not always easy to find out) - influence of social conditions. In addition exposed study populations are different than the population of patients for which the risk estimates are needed in the medical situation. Recent studies aimed to evaluate the available data on the cohorts of the inhabitants of the Techa river settlements as well as of the workers of the Mayak nuclear facilities may provide in the future useful information on large populations chronically exposed to relatively low doses. (Author)

  7. Lung cancer risk at low doses of alpha particles

    International Nuclear Information System (INIS)

    Hofmann, W.; Katz, R.; Zhang, C.X.

    1986-01-01

    A survey of inhabitant exposures arising from the inhalation of 222 Rn and 220 Rn progeny, and lung cancer mortality has been carried out in two adjacent areas in Guangdong Province, People's Republic of China, designated as the high background and the control area. Annual exposure rates are 0.38 working level months (WLM) per year in the high background, and 0.16 WLM/yr in the control area. In 14 yr of continuous study, from 1970 to 1983, age-adjusted mortality rates were found to be 2.7 per 10(5) living persons of all ages in the high background area, and 2.9 per 10(5) living persons in the control area. From this data, we conclude that we are unable to determine excess lung cancers over the normal fluctuations below a cumulative exposure of 15 WLM. This conclusion is supported by lung cancer mortality data from Austrian and Finnish high-background areas. A theoretical analysis of epidemiological data on human lung cancer incidence from inhaled 2 ]2'' 2 Rn and 220 Rn progeny, which takes into account cell killing as competitive with malignant transformation, leads to the evaluation of a risk factor which is either a linear-exponential or a quadratic-exponential function of the alpha-particle dose. Animal lung cancer data and theoretical considerations can be supplied to support either hypothesis. Thus we conclude that at our current stage of knowledge both the linear-exponential and the quadratic-exponential extrapolation to low doses seem to be equally acceptable for Rn-induced lung cancer risk, possibly suggesting a linear-quadratic transformation function with an exponential cell-killing term, or the influence of risk-modifying factors such as repair or proliferation stimuli

  8. Toxicity risk of non-target organs at risk receiving low-dose radiation: case report

    International Nuclear Information System (INIS)

    Shueng, Pei-Wei; Lin, Shih-Chiang; Chang, Hou-Tai; Chong, Ngot-Swan; Chen, Yu-Jen; Wang, Li-Ying; Hsieh, Yen-Ping; Hsieh, Chen-Hsi

    2009-01-01

    The spine is the most common site for bone metastases. Radiation therapy is a common treatment for palliation of pain and for prevention or treatment of spinal cord compression. Helical tomotherapy (HT), a new image-guided intensity modulated radiotherapy (IMRT), delivers highly conformal dose distributions and provides an impressive ability to spare adjacent organs at risk, thus increasing the local control of spinal column metastases and decreasing the potential risk of critical organs under treatment. However, there are a lot of non-target organs at risk (OARs) occupied by low dose with underestimate in this modern rotational IMRT treatment. Herein, we report a case of a pathologic compression fracture of the T9 vertebra in a 55-year-old patient with cholangiocarcinoma. The patient underwent HT at a dose of 30 Gy/10 fractions delivered to T8-T10 for symptom relief. Two weeks after the radiotherapy had been completed, the first course of chemotherapy comprising gemcitabine, fluorouracil, and leucovorin was administered. After two weeks of chemotherapy, however, the patient developed progressive dyspnea. A computed tomography scan of the chest revealed an interstitial pattern with traction bronchiectasis, diffuse ground-glass opacities, and cystic change with fibrosis. Acute radiation pneumonitis was diagnosed. Oncologists should be alert to the potential risk of radiation toxicities caused by low dose off-targets and abscopal effects even with highly conformal radiotherapy

  9. Risk of low-doses in radiodiagnosis; Risque des faibles doses en radiodiagnostic. Mythes, reglementation et rationalite

    Energy Technology Data Exchange (ETDEWEB)

    Cordoliani, Y.S.; Sarrazin, J.L.; Le Frian, G.; Soulie, D.; Leveque, C. [Hopital d`Instruction des Armees du Val-de-Grace, 75 - Paris (France)

    1997-12-31

    The effect of low doses of X-rays is inferred from the indubitable effects of high doses in human carcinogenesis, Genetic and teratogenic effects are mainly inferred from animal experimentation because clinical surveys of irradiated pregnant women have failed to demonstrate such consequences in the children, except for mental retardation after Japanese atomic bombing. Since no evidence of carcinogenic effect has been produced by epidemiological studies for doses lower than 500 mSv. the estimation of the risk due to low doses has been extrapolated from the linear relation between dose and cancers at high doses. Such an extrapolation gives a maximal risk which is falsely used as a probability of cancer. The actual risk lies between zero and this maximal number, and many epidemiologic surveys in people receiving doses much higher than the mean level of background irradiation failed to demonstrate higher rate of cancer. The explanation of this fact, which is supported by the most recent biological data, is the efficacy of the DNA repair system at low level of exposure to ionizing radiations. We expose the principles of regulation of radioprotection for workers, and give estimations of the doses delivered to the patients and the personnel by diagnostic investigations, by comparing these doses with those of natural irradiation. Practical aspect for conventional and computed radiology are exposed for patients and workers. (authors)

  10. Cardiovascular risks associated with low dose ionizing particle radiation.

    Directory of Open Access Journals (Sweden)

    Xinhua Yan

    Full Text Available Previous epidemiologic data demonstrate that cardiovascular (CV morbidity and mortality may occur decades after ionizing radiation exposure. With increased use of proton and carbon ion radiotherapy and concerns about space radiation exposures to astronauts on future long-duration exploration-type missions, the long-term effects and risks of low-dose charged particle irradiation on the CV system must be better appreciated. Here we report on the long-term effects of whole-body proton ((1H; 0.5 Gy, 1 GeV and iron ion ((56Fe; 0.15 Gy, 1GeV/nucleon irradiation with and without an acute myocardial ischemia (AMI event in mice. We show that cardiac function of proton-irradiated mice initially improves at 1 month but declines by 10 months post-irradiation. In AMI-induced mice, prior proton irradiation improved cardiac function restoration and enhanced cardiac remodeling. This was associated with increased pro-survival gene expression in cardiac tissues. In contrast, cardiac function was significantly declined in (56Fe ion-irradiated mice at 1 and 3 months but recovered at 10 months. In addition, (56Fe ion-irradiation led to poorer cardiac function and more adverse remodeling in AMI-induced mice, and was associated with decreased angiogenesis and pro-survival factors in cardiac tissues at any time point examined up to 10 months. This is the first study reporting CV effects following low dose proton and iron ion irradiation during normal aging and post-AMI. Understanding the biological effects of charged particle radiation qualities on the CV system is necessary both for the mitigation of space exploration CV risks and for understanding of long-term CV effects following charged particle radiotherapy.

  11. Risk of solid cancer in low dose-rate radiation epidemiological studies and the dose-rate effectiveness factor.

    Science.gov (United States)

    Shore, Roy; Walsh, Linda; Azizova, Tamara; Rühm, Werner

    2017-10-01

    Estimated radiation risks used for radiation protection purposes have been based primarily on the Life Span Study (LSS) of atomic bomb survivors who received brief exposures at high dose rates, many with high doses. Information is needed regarding radiation risks from low dose-rate (LDR) exposures to low linear-energy-transfer (low-LET) radiation. We conducted a meta-analysis of LDR epidemiologic studies that provide dose-response estimates of total solid cancer risk in adulthood in comparison to corresponding LSS risks, in order to estimate a dose rate effectiveness factor (DREF). We identified 22 LDR studies with dose-response risk estimates for solid cancer after minimizing information overlap. For each study, a parallel risk estimate was derived from the LSS risk model using matching values for sex, mean ages at first exposure and attained age, targeted cancer types, and accounting for type of dosimetric assessment. For each LDR study, a ratio of the excess relative risk per Gy (ERR Gy -1 ) to the matching LSS ERR risk estimate (LDR/LSS) was calculated, and a meta-analysis of the risk ratios was conducted. The reciprocal of the resultant risk ratio provided an estimate of the DREF. The meta-analysis showed a LDR/LSS risk ratio of 0.36 (95% confidence interval [CI] 0.14, 0.57) for the 19 studies of solid cancer mortality and 0.33 (95% CI 0.13, 0.54) when three cohorts with only incidence data also were added, implying a DREF with values around 3, but statistically compatible with 2. However, the analyses were highly dominated by the Mayak worker study. When the Mayak study was excluded the LDR/LSS risk ratios increased: 1.12 (95% CI 0.40, 1.84) for mortality and 0.54 (95% CI 0.09, 0.99) for mortality + incidence, implying a lower DREF in the range of 1-2. Meta-analyses that included only cohorts in which the mean dose was LDR data provide direct evidence regarding risk from exposures at low dose rates as an important complement to the LSS risk estimates used

  12. Risk equivalent of exposure versus dose of radiation

    International Nuclear Information System (INIS)

    Bond, V.P.

    1986-01-01

    Radiation is perhaps unique among all agents of interest in the Health Sciences in that it alone is both a therapeutic agent for the control of cancer and an essentially ubiquitous environmental agent with a potential for increasing the cancer rate in human populations. Therapy of tumors is accomplished with the high-level exposure (HLE) to radiation in order to effect control or a cure. Thus, it conforms to the concepts and approaches of pharmacology, toxicology, and therapeutic medicine. Only one function, that which relates the object-oriented and nonstochastic independent variable organ dose to its effect on a cancer or an organ, is needed to estimate the probability, P 2 , of a quantal response. Only P 2 is needed because P 1 , that the cancer slated for such treatment will receive some amount of the agent and be affected to some degree, is effectively unity. The health problem involving low-level exposure (LLE) to radiation, in contrast, is not at all analogous to those of pharmacology, toxicology, and medicine. Rather, it presents a public health problem in that it is a health population, albeit of cells, that is exposed in a radiation field composed of moving radiation particles with some attendant low-order carcinogenic or mutagenic risk. Thus, the concepts, quantities, and terminology applied to low-level radiation must be modified from their present orientation toward pharmacology, toxicology, medicine, and dose to conform to those of public health and accident statistics, in which both P 1 and P 2 for the exposed cells must be estimated

  13. Application and inspiration of risk control in dose control in Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Yu Shaoqing; Chen Yan; Chai Jianshe; Zhang Chunming

    2013-01-01

    The article introduced the basic concept of risk and risk control methods. Using the risk control methods, we analyzed and evaluated the actions to control dose of public and occupational radiation exposure in the Fukushima Dai-ichi nuclear power plant accident, especially found out the weak points of these actions, and finally discussed the application of the risk control methods in dose management during nuclear accidents. (authors)

  14. An overview of measuring and modelling dose and risk from ionising radiation for medical exposures

    International Nuclear Information System (INIS)

    Tootell, Andrew; Szczepura, Katy; Hogg, Peter

    2014-01-01

    Purpose: This paper gives an overview of the methods that are used to calculate dose and risk from exposure to ionizing radiation as a support to other papers in this special issue. Background: The optimization of radiation dose is a legal requirement in medical exposures. This review paper aims to provide the reader with knowledge of dose by providing definitions and concepts of absorbed, effective and equivalent dose. Criticisms of the use of effective dose to infer the risk of an exposure to an individual will be discussed and an alternative approach considering the lifetime risks of cancer incidence will be considered. Prior to any dose or risk calculation, data concerning the dose absorbed by the patient needs to be collected. This paper will describe and discuss the main concepts and methods that can be utilised by a researcher in dose assessments. Concepts behind figures generated by imaging equipment such as dose-area-product, computed tomography dose index, dose length product and their use in effective dose calculations will be discussed. Processes, advantages and disadvantages in the simulation of exposures using the Monte Carlo method and direct measurement using digital dosimeters or thermoluminescent dosimeters will be considered. Beyond this special issue, it is proposed that this paper could serve as a teaching or CPD tool for personnel working or studying medical imaging

  15. A method to adjust radiation dose-response relationships for clinical risk factors

    DEFF Research Database (Denmark)

    Appelt, Ane Lindegaard; Vogelius, Ivan R

    2012-01-01

    Several clinical risk factors for radiation induced toxicity have been identified in the literature. Here, we present a method to quantify the effect of clinical risk factors on radiation dose-response curves and apply the method to adjust the dose-response for radiation pneumonitis for patients...

  16. Patient-specific radiation dose and cancer risk for pediatric chest CT.

    Science.gov (United States)

    Li, Xiang; Samei, Ehsan; Segars, W Paul; Sturgeon, Gregory M; Colsher, James G; Frush, Donald P

    2011-06-01

    To estimate patient-specific radiation dose and cancer risk for pediatric chest computed tomography (CT) and to evaluate factors affecting dose and risk, including patient size, patient age, and scanning parameters. The institutional review board approved this study and waived informed consent. This study was HIPAA compliant. The study included 30 patients (0-16 years old), for whom full-body computer models were recently created from clinical CT data. A validated Monte Carlo program was used to estimate organ dose from eight chest protocols, representing clinically relevant combinations of bow tie filter, collimation, pitch, and tube potential. Organ dose was used to calculate effective dose and risk index (an index of total cancer incidence risk). The dose and risk estimates before and after normalization by volume-weighted CT dose index (CTDI(vol)) or dose-length product (DLP) were correlated with patient size and age. The effect of each scanning parameter was studied. Organ dose normalized by tube current-time product or CTDI(vol) decreased exponentially with increasing average chest diameter. Effective dose normalized by tube current-time product or DLP decreased exponentially with increasing chest diameter. Chest diameter was a stronger predictor of dose than weight and total scan length. Risk index normalized by tube current-time product or DLP decreased exponentially with both chest diameter and age. When normalized by DLP, effective dose and risk index were independent of collimation, pitch, and tube potential (chest CT protocols. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101900/-/DC1. RSNA, 2011

  17. Imaging dose in breast radiotherapy: does breast size affect the dose to the organs at risk and the risk of secondary cancer to the contralateral breast?

    International Nuclear Information System (INIS)

    Batumalai, Vikneswary; Quinn, Alexandra; Jameson, Michael; Delaney, Geoff; Holloway, Lois

    2015-01-01

    Correct target positioning is crucial for accurate dose delivery in breast radiotherapy resulting in utilisation of daily imaging. However, the radiation dose from daily imaging is associated with increased probability of secondary induced cancer. The aim of this study was to quantify doses associated with three imaging modalities and investigate the correlation of dose and varying breast size in breast radiotherapy. Planning computed tomography (CT) data sets of 30 breast cancer patients were utilised to simulate the dose received by various organs from a megavoltage computed tomography (MV-CT), megavoltage electronic portal image (MV-EPI) and megavoltage cone-beam computed tomography (MV-CBCT). The mean dose to organs adjacent to the target volume (contralateral breast, lungs, spinal cord and heart) were analysed. Pearson correlation analysis was performed to determine the relationship between imaging dose and primary breast volume and the lifetime attributable risk (LAR) of induced secondary cancer was calculated for the contralateral breast. The highest contralateral breast mean dose was from the MV-CBCT (1.79 Gy), followed by MV-EPI (0.22 Gy) and MV-CT (0.11 Gy). A similar trend was found for all organs at risk (OAR) analysed. The primary breast volume inversely correlated with the contralateral breast dose for all three imaging modalities. As the primary breast volume increases, the likelihood of a patient developing a radiation-induced secondary cancer to the contralateral breast decreases. MV-CBCT showed a stronger relationship between breast size and LAR of developing a radiation-induced contralateral breast cancer in comparison with the MV-CT and MV-EPI. For breast patients, imaging dose to OAR depends on imaging modality and treated breast size. When considering the use of imaging during breast radiotherapy, the patient's breast size and contralateral breast dose should be taken into account

  18. The risk of low doses of ionising radiation and the linear no threshold relationship debate

    International Nuclear Information System (INIS)

    Tubiana, M.; Masse, R.; Vathaire, F. de; Averbeck, D.; Aurengo, A.

    2007-01-01

    The ICRP and the B.E.I.R. VII reports recommend a linear no threshold (L.N.T.) relationship for the estimation of cancer excess risk induced by ionising radiations (IR), but the 2005 report of Medicine and Science French Academies concludes that it leads to overestimate of risk for low and very low doses. The bases of L.N.T. are challenged by recent biological and animal experimental studies which show that the defence against IR involves the cell microenvironment and the immunologic system. The defence mechanisms against low doses are different and comparatively more effective than for high doses. Cell death is predominant against low doses. DNA repairing is activated against high doses, in order to preserve tissue functions. These mechanisms provide for multicellular organisms an effective and low cost defence system. The differences between low and high doses defence mechanisms are obvious for alpha emitters which show several greys threshold effects. These differences result in an impairment of epidemiological studies which, for statistical power purpose, amalgamate high and low doses exposure data, since it would imply that cancer IR induction and defence mechanisms are similar in both cases. Low IR dose risk estimates should rely on specific epidemiological studies restricted to low dose exposures and taking precisely into account potential confounding factors. The preliminary synthesis of cohort studies for which low dose data (< 100 mSv) were available show no significant risk excess, neither for solid cancer nor for leukemias. (authors)

  19. Radiation dose and second cancer risk in patients treated for cancer of the cervix

    International Nuclear Information System (INIS)

    Boice, J.D. Jr.; Engholm, G.; Kleinerman, R.A.

    1988-01-01

    The risk of cancer associated with a broad range of organ doses was estimated in an international study of women with cervical cancer. Among 150,000 patients reported to one of 19 population-based cancer registries or treated in any of 20 oncology clinics, 4188 women with second cancers and 6880 matched controls were selected for detailed study. Radiation doses for selected organs were reconstructed for each patient on the basis of her original radiotherapy records. Very high doses, on the order of several hundred gray, were found to increase the risk of cancers of the bladder [relative risk (RR) = 4.0], rectum (RR = 1.8), vagina (RR = 2.7), and possibly bone (RR = 1.3), uterine corpus (RR = 1.3), cecum (RR = 1.5), and non-Hodgkin's lymphoma (RR = 2.5). For all female genital cancers taken together, a sharp dose-response gradient was observed, reaching fivefold for doses more than 150 Gy. Several gray increased the risk of stomach cancer (RR = 2.1) and leukemia (RR = 2.0). Although cancer of the pancreas was elevated, there was no evidence of a dose-dependent risk. Cancer of the kidney was significantly increased among 15-year survivors. A nonsignificant twofold risk of radiogenic thyroid cancer was observed following an average dose of only 0.11 Gy. Breast cancer was not increased overall, despite an average dose of 0.31 Gy and 953 cases available for evaluation (RR = 0.9); there was, however, a weak suggestion of a dose response among women whose ovaries had been surgically removed. Doses greater than 6 Gy to the ovaries reduced breast cancer risk by 44%. A significant deficit of ovarian cancer was observed within 5 years of radiotherapy; in contrast, a dose response was suggested among 10-year survivors

  20. Equivalent dose, effective dose and risk assessment from panoramic radiography to the critical organs of head and neck region

    International Nuclear Information System (INIS)

    Cho, Bong Hae; Nah, Kyung Soo; Lee, Ae Ryeon

    1995-01-01

    The purpose of this study was to evaluate the equivalent and effective dose, and estimate radiation risk to the critical organs of head and neck region from the use of adult and child mode in panoramic radiography. The results were as follows. 1. The salivary glands showed the highest equivalent and effective dose in adult and child mode. The equivalent and effective dose in adult mode were 837 μSv and 20.93 μSv, those in child mode were 462 μSv and 11.54 μSv, respectively. 2. Total effective doses to the critical head and neck organs were estimated 34.2l μSv in adult mode, 20.14 μSv in child mode. From these data, the probabilities of stochastic effect from adult and child mode were 2.50xl0 -6 and 1.47x10 -6 3. The other remainder showed the greatest risk of fatal cancer. The risk estimate were 4.5 and 2.7 fatal malignancies in adult and child mode from million examinations. The bone marrow and thyroid gland showed about 0.1 fatal cancer in adult. and child mode from these examinations.

  1. Risk of radiation-induced cancer at low doses and low dose rates for radiation protection purposes

    International Nuclear Information System (INIS)

    1995-01-01

    The aim of this report is to provide an updated, comprehensive review of the data available for assessing the risk of radiation-induced cancer for radiation protection purposes. Particular emphasis is placed on assessing risks at low doses and low dose rates. The review brings together the results of epidemiological investigations and fundamental studies on the molecular and cellular mechanisms involved in radiation damage. Additionally, this information is supplemented by studies with experimental animals which provide further guidance on the form of the dose-response relationship for cancer induction, as well as on the effect of dose rate on the tumour yield. The emphasis of the report is on cancer induction resulting from exposure to radiations with a low linear energy transfer (LET). The work was performed under contract for the Institut de Protection et de Surete Nucleaire, Fontenay-aux-Roses, Paris, France, whose agreement to publish is gratefully ackowledged. It extends the advice on radiation risks given in Documents of the NRPB, 4 No. 4 (1993). (Author)

  2. Study on the evaluation of radiation doses in dental radiography. Doses and risks due to dental full mouth examination

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, K [Kanagawa Dental Coll., Yokosuka (Japan)

    1980-09-01

    Radiation doses and possible biological risks due to dental full mouth examination (adult: 10-film technique, child: 6-film technique) were evaluated based on preliminary experiments and statistical surveillance of patients' records. Dosimetrical studies were performed by using head and neck phantoms and a dental x-ray tube. Radiation doses were measured by x-ray films and thermoluminescence dosimeters. For the obtained doses of skin, eyes, thyroid gland and bone marrow, the biological risk of leukemia and thyroid cancer was discussed on the statistical basis of patients at Kanagawa Dental College Hospital. The major findings were as follows: The total number of patients who recieved full mouth x-ray examination at Kanagawa Dental College Hospital in 1978 was 1,099. The number of male patients was 382 (3,804 films) and that of female patients was 717 (7,138 films). In both sexes, the number of patients was the greatest in the group of 8 - 14 years of age. The collective doses of bone marrow due to full mouth 10-film examination performed at Kanagawa Dental College Hospital in 1978 were approximately 6.0 rad, which could induce leukemia with a probability of 1/8,000. The collective doses of thyroid gland were approximately 13 rad, which could induce lethal thyroid cancer with a probability of 1/15,000. The radiation dose due to the dental radiography for examination at Kanagawa Dental College Hospital was proved to be apparently below the level that could actually induce radiation injuries. But the collective radiation doses due to dental examination in Japan as a whole were approximately 8,000 times greater than that in Kanagawa Dental College Hospital.

  3. Estimation of outdoor and indoor effective dose and excess lifetime cancer risk from Gamma dose rates in Gonabad, Iran

    Energy Technology Data Exchange (ETDEWEB)

    Jafaria, R.; Zarghania, H.; Mohammadia, A., E-mail: rvzreza@gmail.com [Paramedical faculty, Birjand University of Medical Sciences, Birjand (Iran, Islamic Republic of)

    2017-07-01

    Background gamma irradiation in the indoor and outdoor environments is a major concern in the world. The study area was Gonabad city. Three stations and buildings for background radiation measurement of outdoor and indoor were randomly selected and the Geiger-Muller detector (X5C plus) was used. All dose rates on display of survey meter were recorded and mean of all data in each station and buildings was computed and taken as measured dose rate of that particular station. The average dose rates of background radiation were 84.2 nSv/h for outdoor and 108.6 nSv/h for indoor, maximum and minimum dose rates were 88.9 nSv/h and 77.7 nSv/h for outdoor measurements and 125.4 nSv/h and 94.1 nSv/h for indoor measurements, respectively. Results show that the annual effective dose is 0.64 mSv, which compare to global level of the annual effective dose 0.48 mSv is high. Estimated excess lifetime cancer risk was 2.24×10{sup -3} , indicated that it is large compared to the world average value of 0.25×10{sup -3}. (author)

  4. Low-dose aspirin and risk of intracranial bleeds

    DEFF Research Database (Denmark)

    Cea Soriano, Lucía; Gaist, David; Soriano-Gabarró, Montse

    2017-01-01

    cohort of nonusers of low-dose aspirin at baseline were followed (maximum 14 years, median 5.4 years) to identify incident cases of ICB, with validation by manual review of patient records or linkage to hospitalization data. Using 10,000 frequency-matched controls, adjusted rate ratios (RRs) with 95...

  5. Using spatial information about recurrence risk for robust optimization of dose-painting prescription functions

    International Nuclear Information System (INIS)

    Bender, Edward T.

    2012-01-01

    Purpose: To develop a robust method for deriving dose-painting prescription functions using spatial information about the risk for disease recurrence. Methods: Spatial distributions of radiobiological model parameters are derived from distributions of recurrence risk after uniform irradiation. These model parameters are then used to derive optimal dose-painting prescription functions given a constant mean biologically effective dose. Results: An estimate for the optimal dose distribution can be derived based on spatial information about recurrence risk. Dose painting based on imaging markers that are moderately or poorly correlated with recurrence risk are predicted to potentially result in inferior disease control when compared the same mean biologically effective dose delivered uniformly. A robust optimization approach may partially mitigate this issue. Conclusions: The methods described here can be used to derive an estimate for a robust, patient-specific prescription function for use in dose painting. Two approximate scaling relationships were observed: First, the optimal choice for the maximum dose differential when using either a linear or two-compartment prescription function is proportional to R, where R is the Pearson correlation coefficient between a given imaging marker and recurrence risk after uniform irradiation. Second, the predicted maximum possible gain in tumor control probability for any robust optimization technique is nearly proportional to the square of R.

  6. Cancer incidence after retinoblastoma - Radiation dose and sarcoma risk

    NARCIS (Netherlands)

    Wong, FL; Boice, JD; Abramson, DH; Tarone, RE; Kleinerman, RA; Stovall, M; Goldman, MB; Seddon, JM; Tarbell, N; Fraumeni, JF; Li, FP

    1997-01-01

    Context.-There is a substantial risk of a second cancer for persons with hereditary retinoblastoma, which is enhanced by radiotherapy. Objective.-To examine long-term risk of new primary cancers in survivors of childhood retinoblastoma and quantify the role of radiotherapy in sarcoma development.

  7. Radiation dose to testes and risk of infertility from radiotherapy for rectal cancer.

    Science.gov (United States)

    Mazonakis, Michalis; Damilakis, John; Varveris, Haris; Gourtsouiannis, Nicholas

    2006-03-01

    This study aims to provide the means for testicular dose estimation from radiotherapy for rectal cancer. Rectal irradiation was simulated on a humanoid phantom using a 6 MV photon beam. The effect of field size, distance from irradiated area, wedge introduction into lateral beams, tissue thickness along the beam axis and use of gonad shields on the testicular dose was examined. Testicular dose was measured in five patients undergoing radiotherapy for rectal carcinoma. For a 4500 cGy tumour dose, testicular dose was 32-216 cGy depending upon the field dimensions and the distance from the field isocenter. The presence of wedges increased the testicular dose by a factor up to 2.2. The increase of irradiated tissue thickness increased the gonadal dose up to 40% whereas the use of the appropriate gonad shield reduced the dose by >66%. A simple method was developed to estimate testicular dose. The mean difference between the in vivo gonadal doses and the doses calculated using the proposed method was 5.8%. Testicular dose can exceed the value of 100 cGy, which permits a complete recovery of spermatogenesis. The presented data can be used to estimate the gonadal dose and the associated risk of infertility attributable to rectal irradiation.

  8. Application of probabilistic quantitative ecological risk assessment to radiological dose

    International Nuclear Information System (INIS)

    Twining, J.; Ferris, J.; Copplestone, D.; Zinger, I.

    2004-01-01

    Probabilistic ERA is becoming more accepted and applied in evaluations of environmental impacts worldwide. In a previous paper we have shown that the process can be applied in practice to routine effluent releases from a nuclear facility. However, there are practical issues that need to be addressed prior to its regulatory application for criteria setting or for site-specific ERA. Among these issues are a) appropriate data selection for both exposure and dose-response input, because there is a need to carefully characterise and filter the available dose-response data for its ecological relevance, b) A coherent approach is required to the choice of exposure scenarios, and c) there are various questions associated with treatment of exposure to mixed nuclides. In this paper we will evaluate and discuss aspects of these issues, using an illustrative case study approach. (author)

  9. Improvement of quantification of somatic radiation risks at low doses

    International Nuclear Information System (INIS)

    Jacobi, W.; Paretzke, H.G.; Henrichs, K.; Hettig, H.; Jacob, P.; Merkle, W.; Messerer, P.; Schindel, F.

    1985-10-01

    In this research contract several selected topics of basic relevancy for assessment models of radiological consequences of hypothetical reactor accidents have been considered. The investigations focussed on the following areas: 1) Age dependent dose conversion factors for members of the public and their variability for radioisotopes of iodine, strontium, and caesium, - improvement of the accuracy of dose calculations for external gamma irradiation from cloud- and ground-shine; 2) analysis of data and models relevant for the assessment of exposure-time-effect relationships for lethal somatic late effects of lung and breast cancer and of leukemia; 3) analysis of various health status indices (e.g. ''loss of healthy life span'') with respect to their usefulness in addition to incidence, mortality, etc. for the evaluation of the magnitude of a health detriment due to a previous radiation exposure. (orig./HP) [de

  10. Second International MELODI Workshop on Low Dose Risk Research - Slides of the presentations

    International Nuclear Information System (INIS)

    Repussard, J.; Weiss, W.; Quintana Trias, O.; Rosario Perez, M. del; Andersen, M.; Rudiger Trott, K.; Ottolenghi, A.; Smyth, V.; Graw, J.; Little, M.P.; Yonai, S.; Barcellos-Hoff, M.H.; Bouffler, S.; Chevillard, S.; Jeggo, P.; Sabatier, L.; Baatout, S.; Niwa, O.; Oesch, F.; Atkinson, M.; Averbeck, D.; Lloyd, D.; O'Neill, P.

    2011-01-01

    The MELODI (Multidisciplinary European Low Dose Initiative) mission is to impulse low dose risk research in Europe through a strategic research agenda (SRA) and road-map of priorities. The last presentation is dedicated to the SRA and its preference research programs. The other presentations deal principally with the low-dose exposure in medical uses of ionizing radiations, radiosensitivity, radiation-induced cataracts, or epidemiology and radiobiology of cardiovascular disease. This document is composed of the slides of the presentations

  11. Thyroid Radiation Dose and Other Risk Factors of Thyroid Carcinoma Following Childhood Cancer.

    Science.gov (United States)

    de Vathaire, Florent; Haddy, Nadia; Allodji, Rodrigue S; Hawkins, Mike; Guibout, Catherine; El-Fayech, Chiraz; Teinturier, Cécile; Oberlin, Odile; Pacquement, Hélène; Diop, Fara; Kalhouche, Amar; Benadjaoud, Mohamedamine; Winter, David; Jackson, Angela; Bezin Mai-Quynh, Giao; Benabdennebi, Aymen; Llanas, Damien; Veres, Cristina; Munzer, Martine; Nguyen, Tan Dat; Bondiau, Pierre-Yves; Berchery, Delphine; Laprie, Anne; Deutsch, Eric; Lefkopoulos, Dimitri; Schlumberger, Martin; Diallo, Ibrahima; Rubino, Carole

    2015-11-01

    Thyroid carcinoma is a frequent complication of childhood cancer radiotherapy. The dose response to thyroid radiation dose is now well established, but the potential modifier effect of other factors requires additional investigation. This study aimed to investigate the role of potential modifiers of the dose response. We followed a cohort of 4338 5-year survivors of solid childhood cancer treated before 1986 over an average of 27 years. The dose received by the thyroid gland and some other anatomical sites during radiotherapy was estimated after reconstruction of the actual conditions in which irradiation was delivered. Fifty-five patients developed thyroid carcinoma. The risk of thyroid carcinoma increased with a radiation dose to the thyroid of up to two tenths of Gy, then leveled off for higher doses. When taking into account the thyroid radiation dose, a surgical or radiological splenectomy (>20 Gy to the spleen) increased thyroid cancer risk (relative risk [RR] = 2.3; 95% confidence interval [CI], 1.3-4.0), high radiation doses (>5 Gy) to pituitary gland lowered this risk (RR = 0.2; 95% CI, 0.1-0.6). Patients who received nitrosourea chemotherapy had a 6.6-fold (95% CI, 2.5-15.7) higher risk than those who did not. The excess RR per Gy of radiation to the thyroid was 4.7 (95% CI, 1.7-22.6). It was 7.6 (95% CI, 1.6-33.3) if body mass index at time of interview was equal or higher than 25 kg/m(2), and 4.1 (95% CI, 0.9-17.7) if not (P for interaction = .1). Predicting thyroid cancer risk following childhood cancer radiation therapy probably requires the assessment of more than just the radiation dose to the thyroid. Chemotherapy, splenectomy, radiation dose to pituitary gland, and obesity also play a role.

  12. Low dose diagnostic radiation does not increase cancer risk in cancer prone mice

    Energy Technology Data Exchange (ETDEWEB)

    Boreham, D., E-mail: dboreham@nosm.ca [Northern Ontario School of Medicine, ON (Canada); Phan, N., E-mail: nghiphan13@yahoo.com [Univ. of Ottawa, Ottawa, ON (Canada); Lemon, J., E-mail: lemonja@mcmaster.ca [McMaster Univ., Hamilton, ON (Canada)

    2014-07-01

    The increased exposure of patients to low dose diagnostic ionizing radiation has created concern that these procedures will result in greater risk of carcinogenesis. However, there is substantial evidence that shows in many cases that low dose exposure has the opposite effect. We have investigated whether CT scans can modify mechanisms associated with carcinogenesis in cancer-prone mice. Cancer was induced in Trp53+/- mice with an acute high dose whole-body 4 Gy γ-radiation exposure. Four weeks following the cancer-inducing dose, weekly whole-body CT scans (10 mGy/scan, 75 kVp X-rays) were given for ten consecutive weeks adding an additional radiation burden of 0.1 Gy. Short-term biological responses and subsequent lifetime cancer risk were investigated. Five days following the last CT scan, there were no detectable differences in the spontaneous levels of DNA damage in blood cells (reticulocytes). In fact, CT scanned mice had significantly lower constitutive levels of oxidative DNA damage and cell death (apoptosis), compared to non-CT scanned mice. This shows that multiple low dose radiation exposures modified the radio response and indicates protective processes were induced in mice. In mice treated with the multiple CT scans following the high cancer-inducing 4 Gy dose, tumour latency was increased, significantly prolonging lifespan. We conclude that repeated CT scans can reduce the cancer risk of a prior high-dose radiation exposure, and delay the progression of specific types of radiation-induced cancers in Trp53+/-mice. This research shows for the first time that low dose exposure long after cancer initiation events alter risk and reduce cancer morbidity. Cancer induction following low doses does not follow a linear non-threshold model of risk and this model should not be used to extrapolate risk to humans following low dose exposure to ionizing radiation. (author)

  13. Estimates of radiation doses and cancer risk from food intake in Korea

    International Nuclear Information System (INIS)

    Moon, Eun Kyeong; Lee, Won Jin; Ha, Wi Ho; Seo, Song Won; Jin, Young Woo; Jeong, Kyu Hwan; Yoon, Hae Jung; Kim, Hyoung Soo; Hwang, Myung Sil; Choi, Hoon

    2016-01-01

    After the Fukushima Daiichi nuclear power plant accident, a widespread public concern for radiation exposure through the contamination of domestic or imported food has continued worldwide. Because the internal exposure from contaminated food is an important consideration for human health effect, some studies for estimating radiation doses and cancer risk from the Fukushima nuclear accident have been conducted in several countries (1). The aims of the study is to estimate internal radiation dose and lifetime risks of cancer from food ingestion in Korean population. Our findings suggest no discernible increase n radiation doses or excess fatal cancer risk from food ingestion at this stage in Korea, and provide scientific evidence of the risk communication with general public associated with low-dose radiation exposure.

  14. Estimates of radiation doses and cancer risk from food intake in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Eun Kyeong; Lee, Won Jin [Korea University, Seoul (Korea, Republic of); Ha, Wi Ho; Seo, Song Won; Jin, Young Woo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Jeong, Kyu Hwan [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Yoon, Hae Jung; Kim, Hyoung Soo; Hwang, Myung Sil [Ministry of Food and Drug Safety, Cheongju (Korea, Republic of); Choi, Hoon [Wonkwang University, Iksan (Korea, Republic of)

    2016-04-15

    After the Fukushima Daiichi nuclear power plant accident, a widespread public concern for radiation exposure through the contamination of domestic or imported food has continued worldwide. Because the internal exposure from contaminated food is an important consideration for human health effect, some studies for estimating radiation doses and cancer risk from the Fukushima nuclear accident have been conducted in several countries (1). The aims of the study is to estimate internal radiation dose and lifetime risks of cancer from food ingestion in Korean population. Our findings suggest no discernible increase n radiation doses or excess fatal cancer risk from food ingestion at this stage in Korea, and provide scientific evidence of the risk communication with general public associated with low-dose radiation exposure.

  15. Risks Associated with High-Dose Lactobacillus rhamnosus in an Escherichia coli Model of Piglet Diarrhoea

    DEFF Research Database (Denmark)

    Li, Xiao-Qiong; Zhu, Yao-Hong; Zhang, Hong-Fu

    2012-01-01

    might be more effective than a high dose at ameliorating diarrhoea. There is a risk that high-dose L. rhamnosus pretreatment may negate the preventative effects, thus decreasing the prophylactic benefits against potential enteric pathogens. Our data suggest a safe threshold for preventative use...

  16. Patient doses and radiation risks in film-screen mammography in Finland

    International Nuclear Information System (INIS)

    Servomaa, A.; Parviainen, T.; Komppa, T.

    1995-01-01

    Screen-film mamography is the most sensitive method for the early detection of breast cancer. Breast doses in mamography should be measured for several reasons, especially for the evaluation of patient risk in a screening programme, but also for the assessment and comparison of imaging techniques and equipment performance. In this study, the factors affecting patient doses were assessed by making performance and patient dose measurements; about 50 mammographic units used for screening were included in the study. The lifetime risk as a function of age at exposure was calculated using the average glandular dose, the relative risk model shown in the BEIR V report, and the breast cancer mortality in Finland. The mean surface dose of a 4.5 cm thick phantom was 6.3 mGy, and the mean glandular dose 1.0 mGy. Analysis of the surface dose with respect to film optical density, relative speed of film processing, sensitivity of image receptors, and antiscatter grid showed that the mean surface dose could be decreased by more than 50%. For the screened age group of 50 to 59 years, the risk of exposure-induced death (REID) of breast cancer is about 1.4 x 10 -6 mSv -1 , and the average loss of life expectancy due to the radiation-induced breast cancer deaths (LLE/REID) is about 9.5 years. (Author)

  17. Dose-response relationships and risk estimates for the induction of cancer due to low doses of low-LET radiation

    International Nuclear Information System (INIS)

    Elaguppillai, V.

    1981-01-01

    Risk estimates for radiation-induced cancer at low doses can be obtained only by extrapolation from the known effects at high doses and high dose rates, using a suitable dose-response model. The applicability of three different models, linear, sublinear and supralinear, are discussed in this paper. Several experimental studies tend to favour a sublinear dose-response model (linear-quadratic model) for low-LET radiation. However, human epidemiological studies do not exclude any of the dose-response relationships. The risk estimates based on linear and linear quadratic dose-response models are compared and it is concluded that, for low-LET radiation, the linear dose-response model would probably over-estimate the actual risk of cancer by a factor of two or more. (author)

  18. Radiation dose, reproductive history, and breast cancer risk among Japanese A-bomb survivors

    International Nuclear Information System (INIS)

    Land, C.E.

    1992-01-01

    Excess risk of female breast cancer is among the most comprehensively documented late effects of exposure to substantial doses of ionizing radiation, based on studies of medically irradiated populations and the survivors of the A-bombings of Hiroshima and Nagasaki. This study looks at the interaction of dose with epidemiological factors like age at first full-term pregnancy and family history of breast cancer, most closely associated with risk in epidemiological studies of non-irradiatied populations. 1 fig., 2 tabs

  19. Risk of a second malignant neoplasm after cancer in childhood treated with radiotherapy: correlation with the integral dose

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, F.; Rubino, C.; Guerin, S.; de Vathaire, F. [National Institute of Public Health and Medical Research (INSERM) Unit 605, Institut Gustave-Roussy, Villejuif (France); Diallo, I.; Samand, A. [National Institute of Public Health and Medical Research (INSERM) Unit 605, Institut Gustave-Roussy, Villejuif, (France); Medical Physics and Radiotherapy Departments, Institut Gustave-Roussy, Villejuif (France); Hawkins, M. [Centre for Childhood Cancer Survivor Studies, University of Birmingham, Birmingham (United Kingdom); Oberlin, O. [Paediatrics Department, Institut Gustave-Roussy, Villejuif (France); Lefkopoulos, D. [Medical Physics and Radiotherapy Departments, Institut Gustave-Roussy, Villejuif (France)

    2006-07-01

    In the cohort, among patients who had received radiotherapy, only those who had received the highest integral dose had a higher risk. Among the other patients, including 80% of the variability of the integral dose, no increased risk was evidenced. Thus, the integral dose in the study cannot be considered as a good predictor of later risk. (N.C.)

  20. Risk of a second malignant neoplasm after cancer in childhood treated with radiotherapy: correlation with the integral dose

    International Nuclear Information System (INIS)

    Nguyen, F.; Rubino, C.; Guerin, S.; de Vathaire, F.; Diallo, I.; Samand, A.; Hawkins, M.; Oberlin, O.; Lefkopoulos, D.

    2006-01-01

    In the cohort, among patients who had received radiotherapy, only those who had received the highest integral dose had a higher risk. Among the other patients, including 80% of the variability of the integral dose, no increased risk was evidenced. Thus, the integral dose in the study cannot be considered as a good predictor of later risk. (N.C.)

  1. Comfrey: assessing the low-dose health risk.

    Science.gov (United States)

    Abbott, P J

    The regular use of comfrey as part of the diet or for medicinal purposes may be a potential health risk as a result of the presence of naturally-occurring pyrrolizidine alkaloids. The majority of these alkaloids are hepatotoxic in both animals and humans, and some have been shown to induce tumours in experimental animals. In this article, the toxic properties of pyrrolizidine alkaloids are reviewed briefly, with particular reference to their presence in comfrey. The acute and long-term health risks at the normally-low levels of comfrey consumption are evaluated and discussed. On the basis of the data that are available currently, the small but significant long-term risk that is associated with the consumption of comfrey justifies the need to limit its intake. This is being achieved by controls under various state Poisons Acts, but also requires further education on the potential dangers of naturally-occurring chemicals of plant origin.

  2. Radiation dose and cancer risk among pediatric patients undergoing interventional neuroradiology procedures

    International Nuclear Information System (INIS)

    Thierry-Chef, Isabelle; Simon, Steven L.; Miller, Donald L.

    2006-01-01

    During interventional neuroradiology procedures, patients can be exposed to moderate to high levels of radiation. Special considerations are required to protect children, who are generally more sensitive to the short- and long-term detrimental effects of radiation exposure. Estimates of dose to the skin of children from certain interventional procedures have been published elsewhere, but we are not aware of data on dose to the brain or on the long-term risk of cancer from brain radiation. Our goals were to estimate radiation doses to the brain in 50 pediatric patients who had undergone cerebral embolization and to assess their lifetime risks of developing radiation-related brain cancer. Entrance-peak skin dose and various assumptions on conditions of exposure were used as input for dosimetric calculations to estimate the spatial pattern of dose within the brain and the average dose to the whole brain for each child. The average dose and the age of the child at time of exposure were used to estimate the lifetime risk of developing radiation-related brain cancer. Among the 50 patients, average radiation doses to the brain were estimated to vary from 100 mGy to 1,300 mGy if exposed to non-collimated fields and from 20 mGy to 160 mGy for collimated, moving fields. The lifetime risk of developing brain cancer was estimated to be increased by 2% to 80% as a result of the exposure. Given the very small lifetime background risk of brain tumor, the excess number of cases will be small even though the relative increase might be as high as 80%. ALARA principles of collimation and dose optimization are the most effective means to minimize the risk of future radiation-related cancer. (orig.)

  3. Use of doubling doses for the estimation of genetic risks

    International Nuclear Information System (INIS)

    Searle, A.G.

    1977-01-01

    Doubling dose estimates derived from radiation experiments in mice are proving of great value for the assessment of genetic hazards to man from extra radiation exposure because they allow the latest information on mutation frequencies and the incidence of genetic disease in man to be used in the assessment process. The similarity in spectra of 'spontaneous' and induced mutations increases coincidence in the validity of this approach. Data on rates of induction of dominant and recessive mutations, translocations and X-chromosome loss are used to derive doubling doses for chronic exposures to both low and high-LET radiations. Values for γ and X-rays, derived from both male and female germ-cells, fall inside a fairly small range and it is felt that the use of an overall figure of 100 rads is justifiable for protection purposes. Values for neutrons and α-particles, obtained from male germ-cells, varied according to neutron energy etc. but clustered around a value of 5 rads for fission neutrons

  4. [Radon risk in healthcare facilities: environmental monitoring and effective dose].

    Science.gov (United States)

    Cammarota, B; Cascone, Maria Teresa; De Paola, L; Schillirò, F; Del Prete, U

    2009-01-01

    Radon, the second cause of lung cancer after smoking (WHO- IARC), is a natural, radioactive gas, which originates from the soil and pollutes indoor air, especially in closed or underground spaces. The purpose of this study was to determine the concentration of radon gas, its effective dose, and the measurement of microclimatic degrees C; U.R. % and air velocity in non-academic intensive care units of public hospitals in the Naples area. The annual average concentrations of radon gas were detected with EIC type ionization electret chambers, type LLT with exposure over four 3-month periods. The concentrations varied for all health facilities between 186 and 1191 Bq/m3. Overall, the effective dose of exposure to radon gas of 3mSv/a recommended by Italian legislation was never exceeded. The concentration of radon gas showed a decreasing trend starting from the areas below ground level to those on higher floors; such concentrations were also influenced by natural and artificial ventilation of the rooms, building materials used for walls, and by the state of maintenance and improvements of the building (insulation of floors and walls). The data obtained confirmed the increased concentration of radionuclides in the yellow tuff of volcanic origin in the Campania Region and the resulting rate of release of radon gas, whereas the reinforced concrete structure (a hospital located on the hillside), which had the lowest values, proved to provide good insulation against penetration and accumulation of radon gas.

  5. Implications of effects ''adaptive response'', ''low-dose hypersensitivity'' und ''bystander effect'' for cancer risk at low doses and low dose rates

    International Nuclear Information System (INIS)

    Jacob, P

    2006-01-01

    A model for carcinogenesis (the TSCE model) was applied in order to examine the effects of ''Low-dose hypersensitivity (LDH)'' and the ''Bystander effect (BE)'' on the derivation of radiation related cancer mortality risks. LDH has been discovered to occur in the inactivation of cells after acute exposure to low LET radiation. A corresponding version of the TSCE model was applied to the mortality data on the Abomb survivors from Hiroshima and Nagasaki. The BE has been mainly observed in cells after exposure to high LET radiation. A Version of the TSCE model which included the BE was applied to the data on lung cancer mortality from the workers at the Mayak nuclear facilities who were exposed to Plutonium. In general an equally good description of the A-bomb survivor mortality data (for all solid, stomach and lung tumours) was found for the TSCE model and the (conventional) empirical models but fewer parameters were necessary for the TSCE model. The TSCE model which included the effects of radiation induced cell killing resulted in non-linear dose response curves with excess relative risks after exposure at young ages that were generally lower than in the models without cell killing. The main results from TSCE models which included cell killing described by either conventional survival curves or LDH were very similar. A sub multiplicative effect from the interaction of smoking and exposure to plutonium was found to result from the analysis of the Mayak lung cancer mortality data. All models examined resulted in the predominant number of Mayak lung cancer deaths being ascribed to smoking. The interaction between smoking and plutonium exposures was found to be the second largest effect. The TSCE model resulted in lower estimates for the lung cancer excess relative risk per unit plutonium dose than the empirical risk model, but this difference was not found to be statistically significant. The excess relative risk dose responses were linear in the empirical model and

  6. Geographical distribution of radiation risk unaccountable by direct exposure dose in hiroshima A-bomb victims

    International Nuclear Information System (INIS)

    Tonda, Tetsuji; Satoh, Kenichi; Ohani, Keiko

    2012-01-01

    Death risks due to solid cancer were estimated from region to region where the A-bomb survivors had been actually exposed, to visualize the risk distribution on the map, which resulting in risk regional difference that had been unaccountable by direct exposure dose estimation. Analysis was performed with 3 hazard models of the previous one, + direct exposed dose as a confounding factor and, further, + spatial distance from the explosion point. Subjects were 37,382 A-bomb survivors at Jan. 1, 1970 with known positional coordinate at explosion, followed until Dec. 31, 2009, whose endpoint was set by 4,371 deaths due to cancer except leukemia, cancers of thyroid and breast. Confounding factors in the previous hazard model were sex, age at the exposure, dose and shielding. With the previous model, risk distribution was observed in a concentric circular region around the hypocenter and in an additional west to northwestern suburbs. The latter risk distribution was also seen with the second model in the same region, where dose decreased with -7 powers of the distance. When adjusted with -3 powers of the distance with the third model, the actual risk distribution was found best fitted, indicating the presence of distance-dependent risk. It was suggested that the region exposed to additional dose possibly derived from fallout had been the actual black rainfall area as those regions agreed with each other. (T.T.)

  7. Low-dose total skin electron beam therapy for cutaneous lymphoma : Minimal risk of acute toxicities.

    Science.gov (United States)

    Kroeger, Kai; Elsayad, Khaled; Moustakis, Christos; Haverkamp, Uwe; Eich, Hans Theodor

    2017-12-01

    Low-dose total skin electron beam therapy (TSEBT) is attracting increased interest for the effective palliative treatment of primary cutaneous T‑cell lymphoma (pCTCL). In this study, we compared toxicity profiles following various radiation doses. We reviewed the records of 60 patients who underwent TSEBT for pCTCL between 2000 and 2016 at the University Hospital of Munster. The treatment characteristics of the radiotherapy (RT) regimens and adverse events (AEs) were then analyzed and compared. In total, 67 courses of TSEBT were administered to 60 patients. Of these patients, 34 (51%) received a standard dose with a median surface dose of 30 Gy and 33 patients (49%) received a low dose with the median surface dose of 12 Gy (7 salvage low-dose TSEBT courses were administered to 5 patients). After a median follow-up of 15 months, the overall AE rate was 100%, including 38 patients (57%) with grade 2 and 7 (10%) with grade 3 AEs. Patients treated with low-dose TSEBT had significantly fewer grade 2 AEs than those with conventional dose regimens (33 vs. 79%, P dose regimen compared to those with the conventional dose regimens (6 vs. 15%, P = 0.78). Multiple/salvage low-dose TSEBT courses were not associated with an increased risk of acute AEs. Low-dose TSEBT regimens are associated with significantly fewer grade 2 acute toxicities compared with conventional doses of TSEBT. Repeated/Salvage low-dose TSEBT, however, appears to be tolerable and can even be applied safely in patients with cutaneous relapses.

  8. ANDROS: A code for Assessment of Nuclide Doses and Risks with Option Selection

    International Nuclear Information System (INIS)

    Begovich, C.L.; Sjoreen, A.L.; Ohr, S.Y.; Chester, R.O.

    1986-11-01

    ANDROS (Assessment of Nuclide Doses and Risks with Option Selection) is a computer code written to compute doses and health effects from atmospheric releases of radionuclides. ANDROS has been designed as an integral part of the CRRIS (Computerized Radiological Risk Investigation System). ANDROS reads air concentrations and environmental concentrations of radionuclides to produce tables of specified doses and health effects to selected organs via selected pathways (e.g., ingestion or air immersion). The calculation may be done for an individual at a specific location or for the population of the whole assessment grid. The user may request tables of specific effects for every assessment grid location. Along with the radionuclide concentrations, the code requires radionuclide decay data, dose and risk factors, and location-specific data, all of which are available within the CRRIS. This document is a user manual for ANDROS and presents the methodology used in this code

  9. Modified Exponential (MOE) Models: statistical Models for Risk Estimation of Low dose Rate Radiation

    International Nuclear Information System (INIS)

    Ogata, H.; Furukawa, C.; Kawakami, Y.; Magae, J.

    2004-01-01

    Simultaneous inclusion of dose and dose-rate is required to evaluate the risk of long term irradiation at low dose-rates, since biological responses to radiation are complex processes that depend both on irradiation time and total dose. Consequently, it is necessary to consider a model including cumulative dose,dose-rate and irradiation time to estimate quantitative dose-response relationship on the biological response to radiation. In this study, we measured micronucleus formation and (3H) thymidine uptake in U2OS, human osteosarcoma cell line, as indicators of biological response to gamma radiation. Cells were exposed to gamma ray in irradiation room bearing 50,000 Ci 60Co. After irradiation, they were cultured for 24h in the presence of cytochalasin B to block cytokinesis, and cytoplasm and nucleus were stained with DAPI and propidium iodide. The number of binuclear cells bearing a micronucleus was counted under a florescence microscope. For proliferation inhibition, cells were cultured for 48 h after the irradiation and (3h) thymidine was pulsed for 4h before harvesting. We statistically analyzed the data for quantitative evaluation of radiation risk at low dose/dose-rate. (Author)

  10. Low-dose extrapolation of radiation health risks: some implications of uncertainty for radiation protection at low doses.

    Science.gov (United States)

    Land, Charles E

    2009-11-01

    Ionizing radiation is a known and well-quantified human cancer risk factor, based on a remarkably consistent body of information from epidemiological studies of exposed populations. Typical examples of risk estimation include use of Japanese atomic bomb survivor data to estimate future risk from radiation-related cancer among American patients receiving multiple computed tomography scans, persons affected by radioactive fallout, or persons whose livelihoods involve some radiation exposure, such as x-ray technicians, interventional radiologists, or shipyard workers. Our estimates of radiation-related risk are uncertain, reflecting statistical variation and our imperfect understanding of crucial assumptions that must be made if we are to apply existing epidemiological data to particular situations. Fortunately, that uncertainty is also highly quantifiable, and can be presented concisely and transparently. Radiation protection is ultimately a political process that involves consent by stakeholders, a diverse group that includes people who might be expected to be risk-averse and concerned with plausible upper limits on risk (how bad could it be?), cost-averse and concerned with lower limits on risk (can you prove there is a nontrivial risk at current dose levels?), or combining both points of view. How radiation-related risk is viewed by individuals and population subgroups also depends very much on perception of related benefit, which might be (for example) medical, economic, altruistic, or nonexistent. The following presentation follows the lead of National Council on Radiation Protection and Measurements (NCRP) Commentary 14, NCRP Report 126, and later documents in treating radiation protection from the viewpoint of quantitative uncertainty analysis.

  11. QUANTITATION OF MOLECULAR ENDPOINTS FOR THE DOSE-RESPONSE COMPONENT OF CANCER RISK ASSESSMENT

    Science.gov (United States)

    Cancer risk assessment involves the steps of hazard identification, dose-response assessment, exposure assessment and risk characterization. The rapid advances in the use of molecular biology approaches has had an impact on all four components, but the greatest overall current...

  12. Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

    Science.gov (United States)

    Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

    2006-01-01

    Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low-dose

  13. Effective doses and standardised risk factors from paediatric diagnostic medical radiation exposures: Information for radiation risk communication

    International Nuclear Information System (INIS)

    Bibbo, Giovanni

    2018-01-01

    In the paediatric medical radiation setting, there is no consistency on the radiation risk information conveyed to the consumer (patient/carer). Each communicator may convey different information about the level of risk for the same radiation procedure, leaving the consumer confused and frustrated. There is a need to standardise risks resulting from medical radiation exposures. In this study, paediatric radiographic, fluoroscopic, CT and nuclear medicine examination data have been analysed to provide (i) effective doses and radiation induced cancer risk factors from common radiological and nuclear medicine diagnostic procedures in standardised formats, (II) awareness of the difficulties that may be encountered in communicating risks to the layperson, and (iii) an overview of the deleterious effects of ionising radiation so that the risk communicator can convey with confidence the risks resulting from medical radiation exposures. Paediatric patient dose data from general radiographic, computed tomography, fluoroscopic and nuclear medicine databases have been analysed in age groups 0 to <5 years, 5 to <10 years, 10 to <15 years and 15 to <18 years to determine standardised risk factors. Mean, minimum and maximum effective doses and the corresponding mean lifetime risks for general radiographic, fluoroscopic, CT and nuclear medicine examinations for different age groups have been calculated. For all examinations, the mean lifetime cancer induction risk is provided in three formats: statistical, fraction and category. Standardised risk factors for different radiological and nuclear medicine examinations and an overview of the deleterious effects of ionising radiation and the difficulties encountered in communicating the risks should facilitate risk communication to the patient/carer.

  14. Estimation of breast dose and cancer risk in chest and abdomen CT procedures

    International Nuclear Information System (INIS)

    Eltahir, Suha Abubaker Ali

    2013-05-01

    The use of CT in medical diagnosis delivers radiation doses to patents that are higher than those from other radiological procedures. Lack of optimized protocols be an additional source of increased dose in developing countries. The aims of this study are first, to measure patient doses during CT chest and abdomen procedures, second, to estimate the radiation dose to the breast, and third to quantify the radiation risks during the procedures. Patient doses from two common CT examinations were obtained from four hospitals in Khartoum.The patient doses were estimated using measurement of CT dose indexes (CTDI), exposure-related parameters, and the IMPACT spreadsheet based on NRPB conversion factors. A large variation of mean organ doses among hospitals was observed for similar CT examinations. These variations largely originated from different CT scanning protocols used in different hospitals and scanner type. The largest range was found for CT of the chest, for which the dose varied from 2.3 to 47 (average 24.7) mSv and for abdomen CT, it was 1.6 to 18.8 (average 10.2) mSv. Radiation dose to the breast ranged from 1.6 to 32.9 mSv for the chest and 1.1 to 13.2 mSv for the abdomen. The radiation risk per procedure was high. The obtained values were mostly higher than the values of organ doses reported from the other studies. It was concluded that current clinical chest and abdomen protocols result in variable radiation doses to the breast. The magnitude of exposure may have implications for imaging strategies.(Author)

  15. Post-operative high dose rate brachytherapy in patients with low to intermediate risk endometrial cancer

    International Nuclear Information System (INIS)

    Pearcey, R.G.; Petereit, D.G.

    2000-01-01

    This paper investigates the outcome using different dose/fractionation schedules in high dose rate (HDR) post-operative vaginal vault radiotherapy in patients with low to intermediate risk endometrial cancer. The world literature was reviewed and thirteen series were analyzed representing 1800 cases. A total of 12 vaginal vault recurrences were identified representing an overall vaginal control rate of 99.3%. A wide range of dose fractionation schedules and techniques have been reported. In order to analyze a dose response relationship for tumor control and complications, the biologically effective doses to the tumor and late responding tissues were calculated using the linear quadratic model. A threshold was identified for complications, but not vaginal control. While dose fractionation schedules that delivered a biologically effective dose to the late responding tissues in excess of 100 Gy 3 (LQED = 60 Gy) predicted for late complications, dose fractionation schedules that delivered a modest dose to the vaginal surface (50 Gy 10 or LQED = 30 Gy) appeared tumoricidal with vaginal control rates of at least 98%. By using convenient, modest dose fractionation schedules, HDR vaginal vault - brachytherapy yields very high local control and extremely low morbidity rates. (author)

  16. Patient-specific radiation dose and cancer risk estimation in CT: Part II. Application to patients

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Toncheva, Greta; Yoshizumi, Terry T.; Frush, Donald P. [Medical Physics Graduate Program, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Medical Physics Graduate Program, Department of Physics, and Department of Biomedical Engineering, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Biomedical Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Duke Radiation Dosimetry Laboratory, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Duke Radiation Dosimetry Laboratory, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Division of Pediatric Radiology, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2011-01-15

    Purpose: Current methods for estimating and reporting radiation dose from CT examinations are largely patient-generic; the body size and hence dose variation from patient to patient is not reflected. Furthermore, the current protocol designs rely on dose as a surrogate for the risk of cancer incidence, neglecting the strong dependence of risk on age and gender. The purpose of this study was to develop a method for estimating patient-specific radiation dose and cancer risk from CT examinations. Methods: The study included two patients (a 5-week-old female patient and a 12-year-old male patient), who underwent 64-slice CT examinations (LightSpeed VCT, GE Healthcare) of the chest, abdomen, and pelvis at our institution in 2006. For each patient, a nonuniform rational B-spine (NURBS) based full-body computer model was created based on the patient's clinical CT data. Large organs and structures inside the image volume were individually segmented and modeled. Other organs were created by transforming an existing adult male or female full-body computer model (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. A Monte Carlo program previously developed and validated for dose simulation on the LightSpeed VCT scanner was used to estimate patient-specific organ dose, from which effective dose and risks of cancer incidence were derived. Patient-specific organ dose and effective dose were compared with patient-generic CT dose quantities in current clinical use: the volume-weighted CT dose index (CTDI{sub vol}) and the effective dose derived from the dose-length product (DLP). Results: The effective dose for the CT examination of the newborn patient (5.7 mSv) was higher but comparable to that for the CT examination of the teenager patient (4.9 mSv) due to the size-based clinical CT protocols at our institution, which employ lower scan techniques for smaller

  17. Acute Radiation Risk and BRYNTRN Organ Dose Projection Graphical User Interface

    Science.gov (United States)

    Cucinotta, Francis A.; Hu, Shaowen; Nounu, Hateni N.; Kim, Myung-Hee

    2011-01-01

    The integration of human space applications risk projection models of organ dose and acute radiation risk has been a key problem. NASA has developed an organ dose projection model using the BRYNTRN with SUM DOSE computer codes, and a probabilistic model of Acute Radiation Risk (ARR). The codes BRYNTRN and SUM DOSE are a Baryon transport code and an output data processing code, respectively. The risk projection models of organ doses and ARR take the output from BRYNTRN as an input to their calculations. With a graphical user interface (GUI) to handle input and output for BRYNTRN, the response models can be connected easily and correctly to BRYNTRN. A GUI for the ARR and BRYNTRN Organ Dose (ARRBOD) projection code provides seamless integration of input and output manipulations, which are required for operations of the ARRBOD modules. The ARRBOD GUI is intended for mission planners, radiation shield designers, space operations in the mission operations directorate (MOD), and space biophysics researchers. BRYNTRN code operation requires extensive input preparation. Only a graphical user interface (GUI) can handle input and output for BRYNTRN to the response models easily and correctly. The purpose of the GUI development for ARRBOD is to provide seamless integration of input and output manipulations for the operations of projection modules (BRYNTRN, SLMDOSE, and the ARR probabilistic response model) in assessing the acute risk and the organ doses of significant Solar Particle Events (SPEs). The assessment of astronauts radiation risk from SPE is in support of mission design and operational planning to manage radiation risks in future space missions. The ARRBOD GUI can identify the proper shielding solutions using the gender-specific organ dose assessments in order to avoid ARR symptoms, and to stay within the current NASA short-term dose limits. The quantified evaluation of ARR severities based on any given shielding configuration and a specified EVA or other mission

  18. Noninvasive non Doses Method for Risk Stratification of Breast Diseases

    Directory of Open Access Journals (Sweden)

    I. A. Apollonova

    2014-01-01

    Full Text Available The article concerns a relevant issue that is a development of noninvasive method for screening diagnostics and risk stratification of breast diseases. The developed method and its embodiment use both the analysis of onco-epidemiologic tests and the iridoglyphical research.Widely used onco-epidemiologic tests only reflect the patient’s subjective perception of her own life history and sickness. Therefore to confirm the revealed factors, modern objective and safe methods are necessary.Iridoglyphical research may be considered as one of those methods, since it allows us to reveal changes in iris’ zones in real time. As these zones are functionally linked with intern organs and systems, in this case mammary glands, changes of iris’ zones may be used to assess risk groups for mammary gland disorders.The article presents results of research conducted using a prototype of the hardwaresoftware complex to provide screening diagnostics and risk stratification of mammary gland disorders.Research has been conducted using verified materials, provided by the Biomedical Engineering Faculty and the Scientific Biometry Research and Development Centre of Bauman Moscow State Technical University, the City of Moscow’s GUZ Clinical and Diagnostic Centre N°4 of the Western Administrative District and the First Mammology (Breast Care Centre of the Russian Federation’s Ministry of Health and Social Development.The information, obtained as a result of onco-epidemiological tests and iridoglyphical research, was used to develop a procedure of quantitative diagnostics aimed to assess mammary gland cancer risk groups. The procedure is based on Bayes conditional probability.The task of quantitative diagnostics may be formally divided into the differential assessment of three states. The first, D1, is the norm, which corresponds to the population group with a lack of risk factors or changes of the mammary glands. The second, D2, is the population group

  19. Entyvio lengthen dose-interval study: lengthening vedolizumab dose interval and the risk of clinical relapse in inflammatory bowel disease.

    Science.gov (United States)

    Chan, Webber; Lynch, Nicole; Bampton, Peter; Chang, Jeff; Chung, Alvin; Florin, Timothy; Hetzel, David J; Jakobovits, Simon; Moore, Gregory; Pavli, Paul; Radford-Smith, Graham; Thin, Lena; Baraty, Brandon; Haifer, Craig; Yau, Yunki; Leong, Rupert W L

    2018-07-01

    Vedolizumab (VDZ), an α4β7 anti-integrin antibody, is efficacious in the induction and maintenance of remission in ulcerative colitis (UC) and Crohn's disease (CD). In the GEMINI long-term safety study, enrolled patients received 4-weekly VDZ. Upon completion, patients were switched to 8-weekly VDZ in Australia. The clinical success rate of treatment de-escalation for patients in remission on VDZ has not been described previously. To determine the proportion of patients who relapsed after switching from 4 to 8-weekly VDZ, the mean time to relapse, and the recapture rate when switching back to 8-weekly dosing. This was a retrospective, observational, multicenter study of patients previously recruited into GEMINI long-term safety in Australia. Data on the demographics and biochemical findings were collected. There were 34 patients [23 men, mean age 49.1 (±13.1) years] and their mean disease duration was 17.6 (±8.5) years. The mean 4-weekly VDZ infusion duration was 286.5 (±48.8) weeks. A total of five (15%) patients relapsed on dose-interval increase (4/17 UC, 1/17 CD) at a median duration from dose interval lengthening to flare of 14 weeks (interquartile range=6-25). Eighty percent (4/5) of patients re-entered remission following dose-interval decrease back to 4-weekly. No clinical predictors of relapse could be determined because of the small cohort size. The risk of patients relapsing when switching from 4 to 8-weekly VDZ ∼15% and is similar between CD and UC. Dose-interval decrease recaptures 80% of patients who relapsed. Therapeutic drug monitoring of VDZ may be of clinical relevance.

  20. Thyroid doses and risk to paediatric patients undergoing neck CT examinations

    Energy Technology Data Exchange (ETDEWEB)

    Spampinato, Maria Vittoria; Tipnis, Sameer; Huda, Walter [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Tavernier, Joshua [Medical University of South Carolina, College of Medicine, Charleston, SC (United States)

    2015-07-15

    To estimate thyroid doses and cancer risk for paediatric patients undergoing neck computed tomography (CT). We used average CTDI{sub vol} (mGy) values from 75 paediatric neck CT examinations to estimate thyroid dose in a mathematical anthropomorphic phantom (ImPACT Patient CT Dosimetry Calculator). Patient dose was estimated by modelling the neck as mass equivalent water cylinder. A patient size correction factor was obtained using published relative dose data as a function of water cylinder size. Additional correction factors included scan length and radiation intensity variation secondary to tube-current modulation. The mean water cylinder diameter that modelled the neck was 14 ± 3.5 cm. The mathematical anthropomorphic phantom has a 16.5-cm neck, and for a constant CT exposure, would have thyroid doses that are 13-17 % lower than the average paediatric patient. CTDI{sub vol} was independent of age and sex. The average thyroid doses were 31 ± 18 mGy (males) and 34 ± 15 mGy (females). Thyroid cancer incidence risk was highest for infant females (0.2 %), lowest for teenage males (0.01 %). Estimated absorbed thyroid doses in paediatric neck CT did not significantly vary with age and gender. However, the corresponding thyroid cancer risk is determined by gender and age. (orig.)

  1. Cancer risk at low doses of ionizing radiation. Artificial neural networks inference from atomic bomb survivors

    International Nuclear Information System (INIS)

    Sasaki, Masao S.; Tachibana, Akira; Takeda, Shunichi

    2014-01-01

    Cancer risk at low doses of ionizing radiation remains poorly defined because of ambiguity in the quantitative link to doses below 0.2 Sv in atomic bomb survivors in Hiroshima and Nagasaki arising from limitations in the statistical power and information available on overall radiation dose. To deal with these difficulties, a novel nonparametric statistics based on the ‘integrate-and-fire’ algorithm of artificial neural networks was developed and tested in cancer databases established by the Radiation Effects Research Foundation. The analysis revealed unique features at low doses that could not be accounted for by nominal exposure dose, including (1) the presence of a threshold that varied with organ, gender and age at exposure, and (2) a small but significant bumping increase in cancer risk at low doses in Nagasaki that probably reflects internal exposure to 239 Pu. The threshold was distinct from the canonical definition of zero effect in that it was manifested as negative excess relative risk, or suppression of background cancer rates. Such a unique tissue response at low doses of radiation exposure has been implicated in the context of the molecular basis of radiation–environment interplay in favor of recently emerging experimental evidence on DNA double-strand break repair pathway choice and its epigenetic memory by histone marking. (author)

  2. Why we need new approaches to low-dose risk modeling

    International Nuclear Information System (INIS)

    Alvarez, J.L.; Seiler, F.A.

    1996-01-01

    The linear no-threshold model for radiation effects was introduced as a conservative model for the design of radiation protection programs. The model has persisted not only as the basis for such programs, but has come to be treated as a dogma and is often confused with scientific fact. In this examination a number of serious problems with the linear no-threshold model of radiation carcinogenesis were demonstrated, many of them invalidating the hypothesis. It was shown that the relative risk formalism did not approach 1 as the dose approaches zero. When morality ratios were used instead, the data in the region below 0.3 Sv were systematically below the predictions of the linear model. It was also shown that the data above 0.3 Sv were of little use in formulating a model at low doses. In addition, these data are valid only for doses accumulated at high dose rates, and there is no scientific justification for using the model in low-dose, low-dose-rate extrapolations for purposes of radiation protection. Further examination of model fits to the Japanese survivor data were attempted. Several such models were fit to the data including an unconstrained linear, linear-square root, and Weibull, all of which fit the data better than the relative risk, linear no-threshold model. These fits were used to demonstrate that the linear model systematically over estimates the risk at low doses in the Japanese survivor data set. It is recommended here that an unbiased re-analysis of the data be undertaken and the results used to construct a new model, based on all pertinent data. This model could then form the basis for managing radiation risks in the appropriate regions of dose and dose rate

  3. Systematic review on physician's knowledge about radiation doses and radiation risks of computed tomography

    International Nuclear Information System (INIS)

    Krille, Lucian; Hammer, Gael P.; Merzenich, Hiltrud; Zeeb, Hajo

    2010-01-01

    Background: The frequent use of computed tomography is a major cause of the increasing medical radiation exposure of the general population. Consequently, dose reduction and radiation protection is a topic of scientific and public concern. Aim: We evaluated the available literature on physicians' knowledge regarding radiation dosages and risks due to computed tomography. Methods: A systematic review in accordance with the Cochrane and PRISMA statements was performed using eight databases. 3091 references were found. Only primary studies assessing physicians' knowledge about computed tomography were included. Results: 14 relevant articles were identified, all focussing on dose estimations for CT. Overall, the surveys showed moderate to low knowledge among physicians concerning radiation doses and the involved health risks. However, the surveys varied considerably in conduct and quality. For some countries, more than one survey was available. There was no general trend in knowledge in any country except a slight improvement of knowledge on health risks and radiation doses in two consecutive local German surveys. Conclusions: Knowledge gaps concerning radiation doses and associated health risks among physicians are evident from published research. However, knowledge on radiation doses cannot be interpreted as reliable indicator for good medical practice.

  4. Foetal Radiation Dose and Risk from Diagnostic Radiology Procedures: A Multinational Study

    International Nuclear Information System (INIS)

    Osei, Ernest K.; Darko, Johnson

    2012-01-01

    In diagnostic radiology examinations there is a benefit that the patient derives from the resulting diagnosis. Given that so many examinations are performed each year, it is inevitable that there will be occasions when an examination(s) may be inadvertently performed on pregnant patients or occasionally it may become clinically necessary to perform an examination(s) on a pregnant patient. In all these circumstances it is necessary to request an estimation of the foetal dose and risk. We initiated a study to investigate fetal doses from different countries. Exposure techniques on 367 foetuses from 414 examinations were collected and investigated. The FetDoseV4 program was used for all dose and risk estimations. The radiation doses received by the 367 foetuses ranges: <0.001–21.9 mGy depending on examination and technique. The associated probability of induced hereditary effect ranges: <1 in 200000000 (5 × 10 −9 ) to 1 in 10000 (1 × 10 −4 ) and the risk of childhood cancer ranges <1 in 12500000 (8 × 10 −8 ) to 1 in 500 (2 × 10 −3 ). The data indicates that foetal doses from properly conducted diagnostic radiology examinations will not result in any deterministic effect and a negligible risk of causing radiation induced hereditary effect in the descendants of the unborn child

  5. Testicular dose and associated risk from inverted-Y field irradiation in patients with Hodgkin's disease.

    Science.gov (United States)

    Mazonakis, Michalis; Kokona, Georgiana; Damilakis, John; Varveris, Haris; Gourtsoyiannis, Nicholas

    This study aims to estimate testicular dose and the associated risks for infertility and hereditary effects from inverted-Y field irradiation Radiotherapy was simulated on a humanoid phantom using a 6 MV photon beam. Testicular dose was measured for various field sizes and tissue thicknesses along beam axis using an ionization chamber. Gonadal dose was reduced by placing lead cups around the testes supplemented by a field edge block. For a tumor dose of 40 Gy, testicular dose was 0.56-6.52 Gy depending upon the field size and the distance from the inferior field edge. The corresponding dose to shielded testes was 0.12-1.96 Gy. The increase of tissue thickness in reased the testicular dose up to 40%. An excess risk of hereditary disorders of (7-391) per 10000 births was calculated. The treatment parameters, the presence of gonad shield and the somatometric characteristics determine whether testicular dose can exceed 1 Gy which allows a complete recovery of spermatogenesis.

  6. Tensit - a simulation tool for migration, risk and dose calculations

    International Nuclear Information System (INIS)

    Jones, J.; Kautsky, U.; Vahlund, C.F.

    2004-01-01

    During the next years the Swedish Nuclear Fuel and Waste Management Co (SKB) performs site investigations for a future repository of spent nuclear fuel. The repository will be situated in crystalline rock at a depth of approximately 500 m. Novel methods based on systems and landscape ecology are developed to understand the interacting mechanisms and finally, to model radionuclide migration in the biosphere using site specific data. These models and methods are later used as part of the overall safety assessment for the repository where also migration in the near field and in the bedrock is considered. In the present paper, a newly developed probabilistic simulation package, TENSIT, is presented. The package is based on pre-existing codes (Matlab, Simulink and the probabilistic engine-at-risk) and is capable of performing radionuclide migration calculations both for the repository and the biosphere. Hence, a platform independent, transparent (well documented and intuitive on a model scale), thoroughly supported, efficient and user friendly (graphical interface for the modeler) code can be developed at a fairly low cost. Comparisons with other codes used for compartment based biosphere modelling and the PSACOIN Level 1B exercise shows on a good agreement on the application scale. Moreover, by basing the package on continuously maintained, pre-existing codes, potential risks associated with a less spread software may be avoided. In addition to the compartment based models based on transfer factors, TENSIT is also able to handle the more complex ecosystem models (based on flow of carbon and nutrients) either separately or in combination with the compartment models. Within the project, biosphere migration calculations have been performed using TENSIT for a watershed in the Forsmark area (one of the studied sites). In this simulation, data from the ongoing site investigation program has been used to define the based model. (author)

  7. Computation of thyroid doses and carcinogenic radiation risks to patients undergoing neck CT examinations

    International Nuclear Information System (INIS)

    Huda, W.; Spampinato, M. V.; Tipnis, S. V.; Magill, D.

    2013-01-01

    The aim of the study was to investigate how differences in patient anatomy and CT technical factors in neck CT impact on thyroid doses and the corresponding carcinogenic risks. The CTDI vol and dose-length product used in 11 consecutive neck CT studies, as well as data on automatic exposure control (AEC) tube current variation(s) from the image DICOM header, were recorded. For each CT image that included the thyroid, the mass equivalent water cylinder was estimated based on the patient cross-sectional area and average relative attenuation coefficient (Hounsfield unit, HU). Patient thyroid doses were estimated by accounting for radiation intensity at the location of the patient's thyroid, patient size and the scan length. Thyroid doses were used to estimate thyroid cancer risks as a function of patient demographics using risk factors in BEIR VII. The length of the thyroid glands ranged from 21 to 54 mm with an average length of 42±12 mm. Water cylinder diameters corresponding to the central slice through the patient thyroid ranged from 18 to 32 cm with a mean of 25±5 cm. The average CTDI vol (32-cm phantom) used to perform these scans was 26±6 mGy, but the use of an AEC increased the tube current by an average of 44 % at the thyroid mid-point. Thyroid doses ranged from 29 to 80 mGy, with an average of 55±19 mGy. A 20-y-old female receiving the highest thyroid dose of 80 mGy would have a thyroid cancer risk of nearly 0.1 %, but radiation risks decreased very rapidly with increasing patient age. The key factors that affect thyroid doses in neck CT examinations are the radiation intensity at the thyroid location and the size of the patient. The corresponding patient thyroid cancer risk is markedly influenced by patient sex and age. (authors)

  8. Automation of PCXMC and ImPACT for NASA Astronaut Medical Imaging Dose and Risk Tracking

    Science.gov (United States)

    Bahadori, Amir; Picco, Charles; Flores-McLaughlin, John; Shavers, Mark; Semones, Edward

    2011-01-01

    To automate astronaut organ and effective dose calculations from occupational X-ray and computed tomography (CT) examinations incorporating PCXMC and ImPACT tools and to estimate the associated lifetime cancer risk per the National Council on Radiation Protection & Measurements (NCRP) using MATLAB(R). Methods: NASA follows guidance from the NCRP on its operational radiation safety program for astronauts. NCRP Report 142 recommends that astronauts be informed of the cancer risks from reported exposures to ionizing radiation from medical imaging. MATLAB(R) code was written to retrieve exam parameters for medical imaging procedures from a NASA database, calculate associated dose and risk, and return results to the database, using the Microsoft .NET Framework. This code interfaces with the PCXMC executable and emulates the ImPACT Excel spreadsheet to calculate organ doses from X-rays and CTs, respectively, eliminating the need to utilize the PCXMC graphical user interface (except for a few special cases) and the ImPACT spreadsheet. Results: Using MATLAB(R) code to interface with PCXMC and replicate ImPACT dose calculation allowed for rapid evaluation of multiple medical imaging exams. The user inputs the exam parameter data into the database and runs the code. Based on the imaging modality and input parameters, the organ doses are calculated. Output files are created for record, and organ doses, effective dose, and cancer risks associated with each exam are written to the database. Annual and post-flight exposure reports, which are used by the flight surgeon to brief the astronaut, are generated from the database. Conclusions: Automating PCXMC and ImPACT for evaluation of NASA astronaut medical imaging radiation procedures allowed for a traceable and rapid method for tracking projected cancer risks associated with over 12,000 exposures. This code will be used to evaluate future medical radiation exposures, and can easily be modified to accommodate changes to the risk

  9. Pediatric radiation dose and risk from bone density measurements using a GE Lunar Prodigy scanner.

    Science.gov (United States)

    Damilakis, J; Solomou, G; Manios, G E; Karantanas, A

    2013-07-01

    Effective radiation doses associated with bone mineral density examinations performed on children using a GE Lunar Prodigy fan-beam dual-energy X-ray absorptiometry (DXA) scanner were found to be comparable to doses from pencil-beam DXA devices, i.e., lower than 1 μSv. Cancer risks associated with acquisitions obtained in this study are negligible. No data were found in the literature on radiation doses and potential risks following pediatric DXA performed on GE Lunar DXA scanners. This study aimed to estimate effective doses and associated cancer risks involved in pediatric examinations performed on a GE Lunar Prodigy scanner. Four physical anthropomorphic phantoms representing newborn, 1-, 5-, and 10-year-old patients were employed to simulate DXA exposures. All acquisitions were carried out using the Prodigy scanner. Dose measurements were performed for spine and dual femur using the phantoms simulating the 5- and 10-year-old child. Moreover, doses associated with whole-body examinations were measured for the four phantoms used in the current study. The gender-average effective dose for spine and hip examinations were 0.65 and 0.36 μSv, respectively, for the phantom representing the 5-year-old child and 0.93 and 0.205 μSv, respectively, for the phantom representing the 10-year-old child. Effective doses for whole-body examinations were 0.25, 0.22, 0.19, and 0.15 μSv for the neonate, 1-, 5-, and 10-year old child, respectively. The estimated lifetime cancer risks were negligible, i.e., 0.02-0.25 per million, depending on the sex, age, and type of DXA examination. A formula is presented for the estimation of effective dose from examinations performed on GE Lunar Prodigy scanners installed in other institutions. The effective doses and potential cancer risks associated with pediatric DXA examinations performed on a GE Lunar Prodigy fan-beam scanner were found to be comparable to doses and risks reported from pencil-beam DXA devices.

  10. Conceptus radiation dose and risk from chest screen-film radiography

    International Nuclear Information System (INIS)

    Damilakis, John; Perisinakis, Kostas; Dimovasili, Evangelia; Prassopoulos, Panos; Gourtsoyiannis, Nicholas; Varveris, Haralambos

    2003-01-01

    The objectives of the present study were to (a) estimate the conceptus radiation dose and risks for pregnant women undergoing posteroanterior and anteroposterior (AP) chest radiographs, (b) study the conceptus dose as a function of chest thickness of the patient undergoing chest radiograph, and (c) investigate the possibility of a conceptus to receive a dose of more than 10 mGy, the level above which specific measurements of conceptus doses may be necessary. Thermoluminescent dosimeters were used for dose measurements in anthropomorphic phantoms simulating pregnancy at the three trimesters of gestation. The effect of chest thickness on conceptus dose and risk was studied by adding slabs of lucite on the anterior and posterior surface of the phantom chest. The conceptus risk for radiation-induced childhood fatal cancer and hereditary effects was calculated based on appropriate risk factors. The average AP chest dimension (d a ) was estimated for 51 women of childbearing age from chest CT examinations. The value of d a was estimated to be 22.3 cm (17.4-27.2 cm). The calculated maximum conceptus dose was 107 x 10 -3 mGy for AP chest radiographs performed during the third trimester of pregnancy with maternal chest thickness of 27.2 cm. This calculation was based on dose data obtained from measurements in the phantoms and d a estimated from the patient group. The corresponding average excess of childhood cancer was 10.7 per million patients. The risk for hereditary effects was 1.1 per million births. Radiation dose for a conceptus increases exponentially as chest thickness increases. The conceptus dose at the third trimester is higher than that of the second and first trimesters. The results of the current study suggest that chest radiographs carried out in women at any time during gestation will result in a negligible increase in risk of radiation-induced harmful effects to the unborn child. After a properly performed maternal chest X-ray, there is no need for

  11. Conceptus radiation dose and risk from chest screen-film radiography.

    Science.gov (United States)

    Damilakis, John; Perisinakis, Kostas; Prassopoulos, Panos; Dimovasili, Evangelia; Varveris, Haralambos; Gourtsoyiannis, Nicholas

    2003-02-01

    The objectives of the present study were to (a) estimate the conceptus radiation dose and risks for pregnant women undergoing posteroanterior and anteroposterior (AP) chest radiographs, (b) study the conceptus dose as a function of chest thickness of the patient undergoing chest radiograph, and (c) investigate the possibility of a conceptus to receive a dose of more than 10 mGy, the level above which specific measurements of conceptus doses may be necessary. Thermoluminescent dosimeters were used for dose measurements in anthropomorphic phantoms simulating pregnancy at the three trimesters of gestation. The effect of chest thickness on conceptus dose and risk was studied by adding slabs of lucite on the anterior and posterior surface of the phantom chest. The conceptus risk for radiation-induced childhood fatal cancer and hereditary effects was calculated based on appropriate risk factors. The average AP chest dimension (d(a)) was estimated for 51 women of childbearing age from chest CT examinations. The value of d(a) was estimated to be 22.3 cm (17.4-27.2 cm). The calculated maximum conceptus dose was 107 x 10(-3) mGy for AP chest radiographs performed during the third trimester of pregnancy with maternal chest thickness of 27.2 cm. This calculation was based on dose data obtained from measurements in the phantoms and d(a) estimated from the patient group. The corresponding average excess of childhood cancer was 10.7 per million patients. The risk for hereditary effects was 1.1 per million births. Radiation dose for a conceptus increases exponentially as chest thickness increases. The conceptus dose at the third trimester is higher than that of the second and first trimesters. The results of the current study suggest that chest radiographs carried out in women at any time during gestation will result in a negligible increase in risk of radiation-induced harmful effects to the unborn child. After a properly performed maternal chest X-ray, there is no need for

  12. Conceptus radiation dose and risk from chest screen-film radiography

    Energy Technology Data Exchange (ETDEWEB)

    Damilakis, John; Perisinakis, Kostas; Dimovasili, Evangelia [Department of Medical Physics, University of Crete, Faculty of Medicine, P.O. Box 1393, 714 09 Iraklion, Crete (Greece); Prassopoulos, Panos; Gourtsoyiannis, Nicholas [Department of Radiology, University of Crete, Faculty of Medicine, P.O. Box 1393, 714 09 Iraklion, Crete (Greece); Varveris, Haralambos [Department of Radiotherapy, University of Crete, Faculty of Medicine, P.O. Box 1393, 714 09 Iraklion, Crete (Greece)

    2003-02-01

    The objectives of the present study were to (a) estimate the conceptus radiation dose and risks for pregnant women undergoing posteroanterior and anteroposterior (AP) chest radiographs, (b) study the conceptus dose as a function of chest thickness of the patient undergoing chest radiograph, and (c) investigate the possibility of a conceptus to receive a dose of more than 10 mGy, the level above which specific measurements of conceptus doses may be necessary. Thermoluminescent dosimeters were used for dose measurements in anthropomorphic phantoms simulating pregnancy at the three trimesters of gestation. The effect of chest thickness on conceptus dose and risk was studied by adding slabs of lucite on the anterior and posterior surface of the phantom chest. The conceptus risk for radiation-induced childhood fatal cancer and hereditary effects was calculated based on appropriate risk factors. The average AP chest dimension (d{sub a}) was estimated for 51 women of childbearing age from chest CT examinations. The value of d{sub a} was estimated to be 22.3 cm (17.4-27.2 cm). The calculated maximum conceptus dose was 107 x 10{sup -3} mGy for AP chest radiographs performed during the third trimester of pregnancy with maternal chest thickness of 27.2 cm. This calculation was based on dose data obtained from measurements in the phantoms and d{sub a} estimated from the patient group. The corresponding average excess of childhood cancer was 10.7 per million patients. The risk for hereditary effects was 1.1 per million births. Radiation dose for a conceptus increases exponentially as chest thickness increases. The conceptus dose at the third trimester is higher than that of the second and first trimesters. The results of the current study suggest that chest radiographs carried out in women at any time during gestation will result in a negligible increase in risk of radiation-induced harmful effects to the unborn child. After a properly performed maternal chest X-ray, there is

  13. Low-dose aspirin or other nonsteroidal anti-inflammatory drug use and prostate cancer risk

    DEFF Research Database (Denmark)

    Skriver, Charlotte; Dehlendorff, Christian; Borre, Michael

    2016-01-01

    PURPOSE: Increasing evidence suggests that aspirin use may protect against prostate cancer. In a nationwide case-control study, using Danish high-quality registry data, we evaluated the association between the use of low-dose aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs......) and the risk of prostate cancer. METHODS: We identified 35,600 patients (cases) with histologically verified prostate cancer during 2000-2012. Cases were matched to 177,992 population controls on age and residence by risk-set sampling. Aspirin and nonaspirin NSAID exposure was defined by type, estimated dose......, duration, and consistency of use. We used conditional logistic regression to estimate odds ratios (ORs), with 95 % confidence intervals (CIs), for prostate cancer associated with low-dose aspirin (75-150 mg) or nonaspirin NSAID use, adjusted for potential confounders. RESULTS: Use of low-dose aspirin...

  14. Average annual doses, lifetime doses and associated risk of cancer death for radiation workers in various fuel fabrication facilities in India

    International Nuclear Information System (INIS)

    Iyer, P.S.; Dhond, R.V.

    1980-01-01

    Lifetime doses based on average annual doses are estimated for radiation workers in various fuel fabrication facilities in India. For such cumulative doses, the risk of radiation-induced cancer death is computed. The methodology for arriving at these estimates and the assumptions made are discussed. Based on personnel monitoring records from 1966 to 1978, the average annual dose equivalent for radiation workers is estimated as 0.9 mSv (90 mrem), and the maximum risk of cancer death associated with this occupational dose as 1.35x10 -5 a -1 , as compared with the risk of death due to natural causes of 7x10 -4 a -1 and the risk of death due to background radiation alone of 1.5x10 -5 a -1 . (author)

  15. Radiation dose assessments to support evaluations of radiological control levels for recycling or reuse of materials and equipment

    International Nuclear Information System (INIS)

    Hill, R.L.; Aaberg, R.L.; Baker, D.A.; Kennedy, W.E. Jr.

    1995-07-01

    Pacific Northwest Laboratory is providing Environmental Protection Support and Assistance to the USDOE, Office of Environmental Guidance. Air, Water, and Radiation Division. As part of this effort, PNL is collecting data and conducting technical evaluations to support DOE analyses of the feasibility of developing radiological control levels for recycling or reuse of metals, concrete, or equipment containing residual radioactive contamination from DOE operations. The radiological control levels will be risk-based, as developed through a radiation exposure scenario and pathway analysis. The analysis will include evaluation of relevant radionuclides, potential mechanisms of exposure, and both health and non-health-related impacts. The main objective of this report is to develop a methodology for establishing radiological control levels for recycle or reuse. This report provides the results of the radiation exposure scenario and pathway analyses for 42 key radionuclides generated during DOE operations that may be contained in metals or equipment considered for either recycling or reuse. The scenarios and information developed by the IAEA. Application of Exemption Principles to the Recycle and Reuse of Materials from Nuclear Facilities, are used as the initial basis for this study. The analyses were performed for both selected worker populations at metal smelters and for the public downwind of a smelter facility. Doses to the public downwind were estimated using the US (EPA) CAP88-PC computer code with generic data on atmospheric dispersion and population density. Potential non-health-related effects of residual activity on electronics and on film were also analyzed

  16. Radiation dose assessments to support evaluations of radiological control levels for recycling or reuse of materials and equipment

    Energy Technology Data Exchange (ETDEWEB)

    Hill, R.L.; Aaberg, R.L.; Baker, D.A.; Kennedy, W.E. Jr.

    1995-07-01

    Pacific Northwest Laboratory is providing Environmental Protection Support and Assistance to the USDOE, Office of Environmental Guidance. Air, Water, and Radiation Division. As part of this effort, PNL is collecting data and conducting technical evaluations to support DOE analyses of the feasibility of developing radiological control levels for recycling or reuse of metals, concrete, or equipment containing residual radioactive contamination from DOE operations. The radiological control levels will be risk-based, as developed through a radiation exposure scenario and pathway analysis. The analysis will include evaluation of relevant radionuclides, potential mechanisms of exposure, and both health and non-health-related impacts. The main objective of this report is to develop a methodology for establishing radiological control levels for recycle or reuse. This report provides the results of the radiation exposure scenario and pathway analyses for 42 key radionuclides generated during DOE operations that may be contained in metals or equipment considered for either recycling or reuse. The scenarios and information developed by the IAEA. Application of Exemption Principles to the Recycle and Reuse of Materials from Nuclear Facilities, are used as the initial basis for this study. The analyses were performed for both selected worker populations at metal smelters and for the public downwind of a smelter facility. Doses to the public downwind were estimated using the US (EPA) CAP88-PC computer code with generic data on atmospheric dispersion and population density. Potential non-health-related effects of residual activity on electronics and on film were also analyzed.

  17. No-threshold dose-response curves for nongenotoxic chemicals: Findings and applications for risk assessment

    International Nuclear Information System (INIS)

    Sheehan, Daniel M.

    2006-01-01

    We tested the hypothesis that no threshold exists when estradiol acts through the same mechanism as an active endogenous estrogen. A Michaelis-Menten (MM) equation accounting for response saturation, background effects, and endogenous estrogen level fit a turtle sex-reversal data set with no threshold and estimated the endogenous dose. Additionally, 31 diverse literature dose-response data sets were analyzed by adding a term for nonhormonal background; good fits were obtained but endogenous dose estimations were not significant due to low resolving power. No thresholds were observed. Data sets were plotted using a normalized MM equation; all 178 data points were accommodated on a single graph. Response rates from ∼1% to >95% were well fit. The findings contradict the threshold assumption and low-dose safety. Calculating risk and assuming additivity of effects from multiple chemicals acting through the same mechanism rather than assuming a safe dose for nonthresholded curves is appropriate

  18. Low-dose aspirin use and the risk of ovarian cancer in Denmark

    DEFF Research Database (Denmark)

    Baandrup, Lone; Kjaer, S K; Olsen, J H

    2015-01-01

    BACKGROUND: A comprehensive body of evidence has shown that aspirin has cancer-preventive effects, particularly against gastrointestinal cancer, but its effects on the risk of ovarian cancer are less well established. This nationwide case-control study examined the association between low......-dose aspirin and the risk of ovarian cancer. PATIENTS AND METHODS: We identified all patients in the Danish Cancer Registry aged 30-84 years old with a histologically verified first diagnosis of epithelial ovarian cancer during 2000-2011. Each patient was sex- and age-matched to 15 population controls using...... risk-set sampling. Prescription use, comorbidity, reproductive history, and demographic characteristics data were obtained from nationwide registries. The use of low-dose (75-150 mg) aspirin was defined according to the dose as well as the duration and consistency of use. Conditional logistic...

  19. Three-dimensional dose-response models of risk for radiation injury carcinogenesis

    International Nuclear Information System (INIS)

    Raabe, O.G.

    1988-01-01

    The use of computer graphics in conjunction with three-dimensional models of dose-response relationships for chronic exposure to ionizing radiation dramaticly clarifies the separate and interactive roles of competing risks. The three dimensions are average dose rate, exposure time, and risk. As an example, the functionally injurious and carcinogenic responses after systemic uptake of Ra-226 by beagles, mice and people with consequent alpha particle irradiation of the bone are represented by three-dimensional dose-rate/time/response surfaces that demonstrate the contributions with the passage of time of the competing deleterious responses. These relationships are further evaluated by mathematical stripping with three-dimensional illustrations that graphically show the resultant separate contribution of each effect. Radiation bone injury predominates at high dose rates and bone cancer at intermediate dose rates. Low dose rates result in spontaneous deaths from natural aging, yielding a type of practical threshold for bone cancer induction. Risk assessment is benefited by the insights that become apparent with these three-dimensional models. The improved conceptualization afforded by them contributes to planning and evaluating epidemiological analyses and experimental studies

  20. Radiation exposure to examiners and patients during therapeutic ERCP: Dose optimisation and risk estimation

    International Nuclear Information System (INIS)

    Sulieman, A.; Kappas, K.; Theodorou, K.; Paroutoglou, G.; Kapatenakis, A.; Kapsoritakis, A.; Potamianos, S.; Vlychou, M.; Fezoulidis, I.

    2008-01-01

    Aim: This study intended to optimise the radiation dose during therapeutic ERCP, and to estimate the risk for examiners and patients, to compare the doses based on available data obtained by other researchers and reference levels recommended by international organizations, and to evaluate the technique applied in order to reduce patient and examiners doses. Materials and Methods: 153 patients were studied in two Gastroenterology Departments, (group A, 111; group B, 42). Thermoluminescent dosimeters (TLD) were used to measure the staff and patients entrance surface dose (ESD) at different body sites. Results: The mean ESD, exit and thyroid surface dose per procedure was estimated to be 68.75 mGy, 3.45 mGy and 0.67 mGy, respectively. The mean patient effective dose was 3.44 mSv, and the cancer risk per procedure was estimated to be 190 x10 -6 . The effective dose for the first, second and third examiner was 0.4 μSv, 0.2 μSv and 5.0 μSv, respectively. Conclusion: The patient dose can be optimized by the presence of two experienced examiners and reduction of radiographic images. The examiners should use a wrap around lead apron since the highest dose originating from the X-ray tube, is incident on their side and back. The current formulae, which exist, underestimate the effective dose to the examiners, when they are applied for ERCP procedures. For both patients and examiners, our results were up to 60% lower compared to the lowest values found in previous studies. (authors)

  1. Bleeding Risk with Long-Term Low-Dose Aspirin: A Systematic Review of Observational Studies

    Science.gov (United States)

    García Rodríguez, Luis A.; Martín-Pérez, Mar; Hennekens, Charles H.; Rothwell, Peter M.; Lanas, Angel

    2016-01-01

    Background Low-dose aspirin has proven effectiveness in secondary and primary prevention of cardiovascular events, but is also associated with an increased risk of major bleeding events. For primary prevention, this absolute risk must be carefully weighed against the benefits of aspirin; such assessments are currently limited by a lack of data from general populations. Methods Systematic searches of Medline and Embase were conducted to identify observational studies published between 1946 and 4 March 2015 that reported the risks of gastrointestinal (GI) bleeding or intracranial hemorrhage (ICH) with long-term, low-dose aspirin (75–325 mg/day). Pooled estimates of the relative risk (RR) for bleeding events with aspirin versus non-use were calculated using random-effects models, based on reported estimates of RR (including odds ratios, hazard ratios, incidence rate ratios and standardized incidence ratios) in 39 articles. Findings The incidence of GI bleeding with low-dose aspirin was 0.48–3.64 cases per 1000 person-years, and the overall pooled estimate of the RR with low-dose aspirin was 1.4 (95% confidence interval [CI]: 1.2–1.7). For upper and lower GI bleeding, the RRs with low-dose aspirin were 2.3 (2.0–2.6) and 1.8 (1.1–3.0), respectively. Neither aspirin dose nor duration of use had consistent effects on RRs for upper GI bleeding. The estimated RR for ICH with low-dose aspirin was 1.4 (1.2–1.7) overall. Aspirin was associated with increased bleeding risks when combined with non-steroidal anti-inflammatory drugs, clopidogrel and selective serotonin reuptake inhibitors compared with monotherapy. By contrast, concomitant use of proton pump inhibitors decreased upper GI bleeding risks relative to aspirin monotherapy. Conclusions The risks of major bleeding with low-dose aspirin in real-world settings are of a similar magnitude to those reported in randomized trials. These data will help inform clinical judgements regarding the use of low-dose aspirin

  2. High-Dose Citalopram and Escitalopram and the Risk of Out-of-Hospital Death.

    Science.gov (United States)

    Ray, Wayne A; Chung, Cecilia P; Murray, Katherine T; Hall, Kathi; Stein, C Michael

    2017-02-01

    Studies demonstrating that higher doses of citalopram (> 40 mg) and escitalopram (> 20 mg) prolong the corrected QT interval prompted regulatory agency warnings, which are controversial, given the absence of confirmatory clinical outcome studies. We compared the risk of potential arrhythmia-related deaths for high doses of these selective serotonin reuptake inhibitors (SSRIs) to that for equivalent doses of fluoxetine, paroxetine, and sertraline. The Tennessee Medicaid retrospective cohort study included 54,220 persons 30-74 years of age without cancer or other life-threatening illness who were prescribed high-dose SSRIs from 1998 through 2011. The mean age was 47 years, and 76% were female. Demographic characteristics and comorbidity for individual SSRIs were comparable. Because arrhythmia-related deaths are typically sudden and occur outside the hospital, we analyzed out-of-hospital sudden unexpected death as well as sudden cardiac deaths, a more specific indicator of proarrhythmic effects. The adjusted risk of sudden unexpected death for citalopram did not differ significantly from that for the other SSRIs. The respective hazard ratios (HRs) for citalopram versus escitalopram, fluoxetine, paroxetine, and sertraline were 0.84 (95% CI, 0.40-1.75), 1.24 (95% CI, 0.75-2.05), 0.75 (95% CI, 0.45-1.24), and 1.53 (95% CI, 0.91-2.55). There were no significant differences for sudden cardiac death or all study deaths, nor were there significant differences among high-risk patients (≥ 60 years of age, upper quartile baseline cardiovascular risk). Escitalopram users had no significantly increased risk for any study end point. We found no evidence that risk of sudden unexpected death, sudden cardiac death, or total mortality for high-dose citalopram and escitalopram differed significantly from that for comparable doses of fluoxetine, paroxetine, and sertraline. © Copyright 2016 Physicians Postgraduate Press, Inc.

  3. Three-dimensional dose-response models of competing risks and natural life span

    International Nuclear Information System (INIS)

    Raabe, O.G.

    1987-01-01

    Three-dimensional dose-rate/time/response surfaces for chronic exposure to carcinogens, toxicants, and ionizing radiation dramatically clarify the separate and interactive roles of competing risks. The three dimensions are average dose rate, exposure time, and risk. An illustration with computer graphics shows the contributions with the passage of time of the competing risks of death from radiation pneumonitis/fibrosis, lung cancer, and natural aging consequent to the inhalation of plutonium-239 dioxide by beagles. These relationships are further evaluated by mathematical stripping with three-dimensional illustrations that graphically show the resultant separate contribution of each fatal effect. Radiation pneumonitis predominates at high dose rates and lung cancer at intermediate dose rates. Low dose rates result in spontaneous deaths from natural aging, yielding a type of practical threshold for lung cancer induction. Risk assessment is benefited by the insights that become apparent with these three-dimensional models. The improved conceptualization afforded by them contributes to the planning and evaluation of epidemiological analyses and experimental studies involving chronic exposure to toxicants

  4. The role of uncertainty analysis in dose reconstruction and risk assessment

    International Nuclear Information System (INIS)

    Hoffman, F.O.; Simon, S.L.; Thiessen. K.M.

    1996-01-01

    Dose reconstruction and risk assessment rely heavily on the use of mathematical models to extrapolate information beyond the realm of direct observation. Because models are merely approximations of real systems, their predictions are inherently uncertain. As a result, full disclosure of uncertainty in dose and risk estimates is essential to achieve scientific credibility and to build public trust. The need for formal analysis of uncertainty in model predictions was presented during the nineteenth annual meeting of the NCRP. At that time, quantitative uncertainty analysis was considered a relatively new and difficult subject practiced by only a few investigators. Today, uncertainty analysis has become synonymous with the assessment process itself. When an uncertainty analysis is used iteratively within the assessment process, it can guide experimental research to refine dose and risk estimates, deferring potentially high cost or high consequence decisions until uncertainty is either acceptable or irreducible. Uncertainty analysis is now mandated for all ongoing dose reconstruction projects within the United States, a fact that distinguishes dose reconstruction from other types of exposure and risk assessments. 64 refs., 6 figs., 1 tab

  5. Radiation dose and radiation risk to foetuses and newborns during X-ray examinations

    Energy Technology Data Exchange (ETDEWEB)

    Kettunen, A. [Oulu Univ. (Finland)

    2004-05-01

    The purpose of this study is to determine the way in which the demands set by degree 423/2000 by the Ministry of Social Affairs and Health are fulfilled with respect to the most radiosensitive groups, the foetus and the child, by estimating the radiation dose and radiation risk to the foetus from x-ray examinations of an expectant mother's pelvic region, finding out the practice involved in preventing doses to embryos and foetuses and assessing dose practices in cases where an embryo or foetus is or shall be exposed, and by estimating radiation dose and risk due to the radiation received by a new-born being treated in a paediatric intensive care unit. No statistics are available in Finland to indicate how many x-ray examinations of the pelvic region and lower abdomen are made to pregnant patients or to show the dose and risk to the foetus due these examinations. In order to find out the practices in radiological departments concerning the pelvic x-ray examination of fertile woman and the number of foetuses exposed, a questionnaire was sent to all radiation safety officers responsible for the safe use of radiation (n = 290). A total of 173 questionnaires were returned. This study recorded the technique and Dose-Area Product of 118 chest examinations of newborns in paediatric intensive care units. Entrance surface doses and effective doses were calculated separately to each newborn. Based on the patient records, the number of all x-ray examinations during the study was calculated and the effective doses were estimated retrospectively to each child. The radiation risk was estimated both for the foetuses and for the newborns. According to this study, it is rare in Finland to expose a pregnant woman to radiation. On the other hand, with the exception of pelvimetry examinations, there are no compiled statistics concerning the number of pelvic x-ray examinations of a pregnant woman. There was no common practice on how to exclude the possibility of pregnancy. The dose

  6. Radiation dose and radiation risk to foetuses and newborns during X-ray examinations

    International Nuclear Information System (INIS)

    Kettunen, A.

    2004-05-01

    The purpose of this study is to determine the way in which the demands set by degree 423/2000 by the Ministry of Social Affairs and Health are fulfilled with respect to the most radiosensitive groups, the foetus and the child, by estimating the radiation dose and radiation risk to the foetus from x-ray examinations of an expectant mother's pelvic region, finding out the practice involved in preventing doses to embryos and foetuses and assessing dose practices in cases where an embryo or foetus is or shall be exposed, and by estimating radiation dose and risk due to the radiation received by a new-born being treated in a paediatric intensive care unit. No statistics are available in Finland to indicate how many x-ray examinations of the pelvic region and lower abdomen are made to pregnant patients or to show the dose and risk to the foetus due these examinations. In order to find out the practices in radiological departments concerning the pelvic x-ray examination of fertile woman and the number of foetuses exposed, a questionnaire was sent to all radiation safety officers responsible for the safe use of radiation (n = 290). A total of 173 questionnaires were returned. This study recorded the technique and Dose-Area Product of 118 chest examinations of newborns in paediatric intensive care units. Entrance surface doses and effective doses were calculated separately to each newborn. Based on the patient records, the number of all x-ray examinations during the study was calculated and the effective doses were estimated retrospectively to each child. The radiation risk was estimated both for the foetuses and for the newborns. According to this study, it is rare in Finland to expose a pregnant woman to radiation. On the other hand, with the exception of pelvimetry examinations, there are no compiled statistics concerning the number of pelvic x-ray examinations of a pregnant woman. There was no common practice on how to exclude the possibility of pregnancy. The dose to a

  7. Radiation dose and cancer risk estimates in helical CT for pulmonary tuberculosis infections

    Directory of Open Access Journals (Sweden)

    Adeleye Bamise

    2017-12-01

    Full Text Available The preference for computed tomography (CT for the clinical assessment of pulmonary tuberculosis (PTB infections has increased the concern about the potential risk of cancer in exposed patients. In this study, we investigated the correlation between cancer risk and radiation doses from different CT scanners, assuming an equivalent scan protocol. Radiation doses from three 16-slice units were estimated using the CT-Expo dosimetry software version 2.4 and standard CT scan protocol for patients with suspected PTB infections. The lifetime risk of cancer for each scanner was determined using the methodology outlined in the BEIR VII report. Organ doses were significantly different (P < 0.05 between the scanners. The calculated effective dose for scanner H2 is 34% and 37% higher than scanners H3 and H1 respectively. A high and statistically significant correlation was observed between estimated lifetime cancer risk for both male (r2 = 0.943, P < 0.05 and female patients (r2 = 0.989, P < 0.05. The risk variation between the scanners was slightly higher than 2% for all ages but was much smaller for specific ages for male and female patients (0.2% and 0.7%, respectively. These variations provide an indication that the use of a scanner optimizing protocol is imperative.

  8. Estimating doses and risks associated with decontamination and decommissioning activities using the CRRIS

    International Nuclear Information System (INIS)

    Miller, C.W.; Sjoreen, A.L.; Cotter, S.J.

    1986-01-01

    The Computerized Radiological Risk Investigation System (CRRIS) is applicable to determining doses and risks from a variety of decontamination and decommissioning activities. For example, concentrations in air from resuspended radionuclides initially deposited on the ground surface and the concentrations of deposited radionuclides in various soil layers can be obtained. The CRRIS will estimate exposure to radon and its progeny in terms of working-level months, and will compute the resulting health risks. The CRRIS consists of seven integrated computer codes that stand alone or are run as a system to calculate environmental transport, doses, and risks. PRIMUS output provides other CRRIS codes the capability to handle radionuclide decay chains. ANEMOS and RETADD-II calculate atmospheric dispersion and deposition for local and regional distances, respectively. Multiple ANEMOS runs for sources within a small area are combined on a master grid by SUMIT. MLSOIL is used to estimate effective ground surface concentrations for dose computations. TERRA calculates food chain transport, and ANDROS calculates individual or population exposures, doses, and risks. Applications of the CRRIS to decontamination problems are discussed. 16 refs., 1 fig

  9. Assessing doses of radiotherapy with the risk of developing cancer in the head and neck

    International Nuclear Information System (INIS)

    Yu, Cheng-Ching; Hsu, Fang-Yuh; Yu, Wan-Hsuan; Liu, Mu-Tai; Huang, Sheng-Shien

    2011-01-01

    Radiation is known to be a major cause of cancer in normal tissue. After treatment with radiotherapy, for young patients or the patients can survive for a long time, the radiation-induced cancer risk is noteworthy. This research investigated the dose delivered by the treatment of intensity modulated radiation therapy (IMRT) for head and neck cancer, such as NPC and oral cancer, and assessed the risk of developing radiation-induced secondary cancer in non-targeted normal tissues. A Rando phantom was used to simulate a patient with NPC or oral cancer, and thermoluminescent dosimeter (TLD) chips were placed inside the phantom to estimate the doses delivered by IMRT. In summary, the risks to patients with NPC was somewhat higher than for those with oral cancer, because the region of the PTV was lower, requiring larger field sizes be used for cases of NPC. The smaller the field size used, the less the risk was of developing secondary cancer. In addition, the higher the value of MU used, the higher the dose delivered to normal tissues was. The risk of radiation-induced secondary cancer was proportional to the delivered dose.

  10. Radiation dose and cancer risk estimates in helical CT for pulmonary tuberculosis infections

    Science.gov (United States)

    Adeleye, Bamise; Chetty, Naven

    2017-12-01

    The preference for computed tomography (CT) for the clinical assessment of pulmonary tuberculosis (PTB) infections has increased the concern about the potential risk of cancer in exposed patients. In this study, we investigated the correlation between cancer risk and radiation doses from different CT scanners, assuming an equivalent scan protocol. Radiation doses from three 16-slice units were estimated using the CT-Expo dosimetry software version 2.4 and standard CT scan protocol for patients with suspected PTB infections. The lifetime risk of cancer for each scanner was determined using the methodology outlined in the BEIR VII report. Organ doses were significantly different (P < 0.05) between the scanners. The calculated effective dose for scanner H2 is 34% and 37% higher than scanners H3 and H1 respectively. A high and statistically significant correlation was observed between estimated lifetime cancer risk for both male (r2 = 0.943, P < 0.05) and female patients (r2 = 0.989, P < 0.05). The risk variation between the scanners was slightly higher than 2% for all ages but was much smaller for specific ages for male and female patients (0.2% and 0.7%, respectively). These variations provide an indication that the use of a scanner optimizing protocol is imperative.

  11. Radiation therapy for stage IIA and IIB testicular seminoma: peripheral dose calculations and risk assessments

    Science.gov (United States)

    Mazonakis, Michalis; Berris, Theocharris; Lyraraki, Efrossyni; Damilakis, John

    2015-03-01

    This study was conducted to calculate the peripheral dose to critical structures and assess the radiation risks from modern radiotherapy for stage IIA/IIB testicular seminoma. A Monte Carlo code was used for treatment simulation on a computational phantom representing an average adult. The initial treatment phase involved anteroposterior and posteroanaterior modified dog-leg fields exposing para-aortic and ipsilateral iliac lymph nodes followed by a cone-down phase for nodal mass irradiation. Peripheral doses were calculated using different modified dog-leg field dimensions and an extended conventional dog-leg portal. The risk models of the BEIR-VII report and ICRP-103 were combined with dosimetric calculations to estimate the probability of developing stochastic effects. Radiotherapy for stage IIA seminoma with a target dose of 30 Gy resulted in a range of 23.0-603.7 mGy to non-targeted peripheral tissues and organs. The corresponding range for treatment of stage IIB disease to a cumulative dose of 36 Gy was 24.2-633.9 mGy. A dose variation of less than 13% was found by altering the field dimensions. Radiotherapy with the conventional instead of the modern modified dog-leg field increased the peripheral dose up to 8.2 times. The calculated heart doses of 589.0-632.9 mGy may increase the risk for developing cardiovascular diseases whereas the testicular dose of more than 231.9 mGy may lead to a temporary infertility. The probability of birth abnormalities in the offspring of cancer survivors was below 0.13% which is much lower than the spontaneous mutation rate. Abdominoplevic irradiation may increase the lifetime intrinsic risk for the induction of secondary malignancies by 0.6-3.9% depending upon the site of interest, patient’s age and tumor dose. Radiotherapy for stage IIA/IIB seminoma with restricted fields and low doses is associated with an increased morbidity. These data may allow the definition of a risk-adapted follow-up scheme for long

  12. Hormesis: from marginalization to mainstream A case for hormesis as the default dose-response model in risk assessment

    International Nuclear Information System (INIS)

    Calabrese, Edward J.

    2004-01-01

    The paper provides an account of how the hormetic dose response has emerged in recent years as a serious dose-response model in toxicology and risk assessment after decades of extreme marginalization. In addition to providing the toxicological basis of this dose-response revival, the paper reexamines the concept of a default dose model in toxicology and risk assessment and makes the argument that the hormetic model satisfies criteria (e.g., generalizability, frequency, application to risk assessment endpoints, false positive/negative potential, requirements for hazard assessment, reliability of estimating risks, capacity for validation of risk estimates, public health implications of risk estimates) for such a default model better than its chief competitors, the threshold and linear at low dose models. The selection of the hormetic model as the default model in risk assessment for noncarcinogens and specifically for carcinogens would have a profound impact on the practice of risk assessment and its societal implications

  13. Burden of upper gastrointestinal symptoms in patients receiving low-dose acetylsalicylic acid for cardiovascular risk management

    DEFF Research Database (Denmark)

    Bytzer, Peter; Pratt, Stephen; Elkin, Eric

    2013-01-01

    Continuous low-dose acetylsalicylic acid (aspirin; ASA) is a mainstay of cardiovascular (CV) risk management. It is well established, however, that troublesome upper gastrointestinal (GI) symptoms are commonly experienced among low-dose ASA users.......Continuous low-dose acetylsalicylic acid (aspirin; ASA) is a mainstay of cardiovascular (CV) risk management. It is well established, however, that troublesome upper gastrointestinal (GI) symptoms are commonly experienced among low-dose ASA users....

  14. Genetic radiation risks: a neglected topic in the low dose debate

    Directory of Open Access Journals (Sweden)

    Inge Schmitz-Feuerhake

    2016-01-01

    Full Text Available Objectives To investigate the accuracy and scientific validity of the current very low risk factor for hereditary diseases in humans following exposures to ionizing radiation adopted by the United Nations Scientific Committee on the Effects of Atomic Radiation and the International Commission on Radiological Protection. The value is based on experiments on mice due to reportedly absent effects in the Japanese atomic bomb (Abomb survivors. Methods To review the published evidence for heritable effects after ionising radiation exposures particularly, but not restricted to, populations exposed to contamination from the Chernobyl accident and from atmospheric nuclear test fallout. To make a compilation of findings about early deaths, congenital malformations, Down’s syndrome, cancer and other genetic effects observed in humans after the exposure of the parents. To also examine more closely the evidence from the Japanese A-bomb epidemiology and discuss its scientific validity. Results Nearly all types of hereditary defects were found at doses as low as one to 10 mSv. We discuss the clash between the current risk model and these observations on the basis of biological mechanism and assumptions about linear relationships between dose and effect in neonatal and foetal epidemiology. The evidence supports a dose response relationship which is non-linear and is either biphasic or supralinear (hogs-back and largely either saturates or falls above 10 mSv. Conclusions We conclude that the current risk model for heritable effects of radiation is unsafe. The dose response relationship is non-linear with the greatest effects at the lowest doses. Using Chernobyl data we derive an excess relative risk for all malformations of 1.0 per 10 mSv cumulative dose. The safety of the Japanese A-bomb epidemiology is argued to be both scientifically and philosophically questionable owing to errors in the choice of control groups, omission of internal exposure effects and

  15. Overview of Graphical User Interface for ARRBOD (Acute Radiation Risk and BRYNTRN Organ Dose Projection)

    Science.gov (United States)

    Kim, Myung-Hee Y.; Hu, Shaowen; Nounu, Hatem N.; Cucinotta, Francis A.

    2010-01-01

    Solar particle events (SPEs) pose the risk of acute radiation sickness (ARS) to astronauts, because organ doses from large SPEs may reach critical levels during extra vehicular activities (EVAs) or lightly shielded spacecraft. NASA has developed an organ dose projection model of Baryon transport code (BRYNTRN) with an output data processing module of SUMDOSE, and a probabilistic model of acute radiation risk (ARR). BRYNTRN code operation requires extensive input preparation, and the risk projection models of organ doses and ARR take the output from BRYNTRN as an input to their calculations. With a graphical user interface (GUI) to handle input and output for BRYNTRN, these response models can be connected easily and correctly to BRYNTRN in a user friendly way. The GUI for the Acute Radiation Risk and BRYNTRN Organ Dose (ARRBOD) projection code provides seamless integration of input and output manipulations required for operations of the ARRBOD modules: BRYNTRN, SUMDOSE, and the ARR probabilistic response model. The ARRBOD GUI is intended for mission planners, radiation shield designers, space operations in the mission operations directorate (MOD), and space biophysics researchers. Assessment of astronauts organ doses and ARS from the exposure to historically large SPEs is in support of mission design and operation planning to avoid ARS and stay within the current NASA short-term dose limits. The ARRBOD GUI will serve as a proof-of-concept for future integration of other risk projection models for human space applications. We present an overview of the ARRBOD GUI product, which is a new self-contained product, for the major components of the overall system, subsystem interconnections, and external interfaces.

  16. Mechanisms of Enhanced Cell Killing at Low Doses: Implications for Radiation Risk

    International Nuclear Information System (INIS)

    Johnston, Peter J.; Wilson, George D.

    2003-01-01

    We have shown that cell lethality actually measured after exposure to low-doses of low-LET radiation, is markedly enhanced relative to the cell lethality previously expected by extrapolation of the high-dose cell-killing response. Net cancer risk is a balance between cell transformation and cell kill and such enhanced lethality may more than compensate for transformation at low radiation doses over a least the first 10 cGy of low-LET exposure. This would lead to a non-linear, threshold, dose-risk relationship. Therefore our data imply the possibility that the adverse effects of small radiation doses (<10 cGy) could be overestimated in specific cases. It is now important to research the mechanisms underlying the phenomenon of low-dose hypersensitivity to cell killing, in order to determine whether this can be generalized to safely allow an increase in radiation exposure limits. This would have major cost-reduction implications for the whole EM program

  17. Concomitant Imaging Dose and Cancer Risk in Image Guided Thoracic Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yibao; Wu, Hao [Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Radiotherapy, Peking University Cancer Hospital & Institute, Beijing (China); Chen, Zhe [Department of Therapeutic Radiology, Yale University, New Haven, Connecticut (United States); Knisely, Jonathan P.S. [Department of Radiation Medicine, Hofstra North Shore-LIJ School of Medicine, Hempstead, New York (United States); Nath, Ravinder [Department of Therapeutic Radiology, Yale University, New Haven, Connecticut (United States); Feng, Zhongsu [Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Radiotherapy, Peking University Cancer Hospital & Institute, Beijing (China); Bao, Shanglian [Beijing Key Laboratory of Medical Physics and Engineering, Peking University, Beijing (China); Deng, Jun, E-mail: jun.deng@yale.edu [Department of Therapeutic Radiology, Yale University, New Haven, Connecticut (United States)

    2015-11-01

    Purpose: Kilovoltage cone beam computed tomography (CT) (kVCBCT) imaging guidance improves the accuracy of radiation therapy but imposes an extra radiation dose to cancer patients. This study aimed to investigate concomitant imaging dose and associated cancer risk in image guided thoracic radiation therapy. Methods and Materials: The planning CT images and structure sets of 72 patients were converted to CT phantoms whose chest circumferences (C{sub chest}) were calculated retrospectively. A low-dose thorax protocol on a Varian kVCBCT scanner was simulated by a validated Monte Carlo code. Computed doses to organs and cardiac substructures (for 5 selected patients of various dimensions) were regressed as empirical functions of C{sub chest}, and associated cancer risk was calculated using the published models. The exposures to nonthoracic organs in children were also investigated. Results: The structural mean doses decreased monotonically with increasing C{sub chest}. For all 72 patients, the median doses to the heart, spinal cord, breasts, lungs, and involved chest were 1.68, 1.33, 1.64, 1.62, and 1.58 cGy/scan, respectively. Nonthoracic organs in children received 0.6 to 2.8 cGy/scan if they were directly irradiated. The mean doses to the descending aorta (1.43 ± 0.68 cGy), left atrium (1.55 ± 0.75 cGy), left ventricle (1.68 ± 0.81 cGy), and right ventricle (1.85 ± 0.84 cGy) were significantly different (P<.05) from the heart mean dose (1.73 ± 0.82 cGy). The blade shielding alleviated the exposure to nonthoracic organs in children by an order of magnitude. Conclusions: As functions of patient size, a series of models for personalized estimation of kVCBCT doses to thoracic organs and cardiac substructures have been proposed. Pediatric patients received much higher doses than did the adults, and some nonthoracic organs could be irradiated unexpectedly by the default scanning protocol. Increased cancer risks and disease adverse events in the

  18. Task-based measures of image quality and their relation to radiation dose and patient risk

    International Nuclear Information System (INIS)

    Barrett, Harrison H; Kupinski, Matthew A; Myers, Kyle J; Hoeschen, Christoph; Little, Mark P

    2015-01-01

    The theory of task-based assessment of image quality is reviewed in the context of imaging with ionizing radiation, and objective figures of merit (FOMs) for image quality are summarized. The variation of the FOMs with the task, the observer and especially with the mean number of photons recorded in the image is discussed. Then various standard methods for specifying radiation dose are reviewed and related to the mean number of photons in the image and hence to image quality. Current knowledge of the relation between local radiation dose and the risk of various adverse effects is summarized, and some graphical depictions of the tradeoffs between image quality and risk are introduced. Then various dose-reduction strategies are discussed in terms of their effect on task-based measures of image quality. (topical review)

  19. Low-dose aspirin and risk of intracranial bleeds: An observational study in UK general practice.

    Science.gov (United States)

    Cea Soriano, Lucía; Gaist, David; Soriano-Gabarró, Montse; Bromley, Susan; García Rodríguez, Luis A

    2017-11-28

    To quantify the risk of intracranial bleeds (ICBs) associated with new use of prophylactic low-dose aspirin using a population-based primary care database in the United Kingdom. A cohort of new users of low-dose aspirin (75-300 mg; n = 199,079) aged 40-84 years and a 1:1 matched cohort of nonusers of low-dose aspirin at baseline were followed (maximum 14 years, median 5.4 years) to identify incident cases of ICB, with validation by manual review of patient records or linkage to hospitalization data. Using 10,000 frequency-matched controls, adjusted rate ratios (RRs) with 95% confidence intervals (CIs) were calculated for current low-dose aspirin use (0-7 days before the index date [ICB date for cases, random date for controls]); reference group was never used. There were 1,611 cases of ICB (n = 743 for intracerebral hemorrhage [ICH], n = 483 for subdural hematoma [SDH], and n = 385 for subarachnoid hemorrhage [SAH]). RRs (95% CI) were 0.98 (0.84-1.13) for all ICB, 0.98 (0.80-1.20) for ICH, 1.23 (0.95-1.59) for SDH, and 0.77 (0.58-1.01) for SAH. No duration of use or dose-response association was apparent. RRs (95% CI) for ≥1 year of low-dose aspirin use were 0.90 (0.72-1.13) for ICH, 1.20 (0.91-1.57) for SDH, and 0.69 (0.50-0.94) for SAH. Low-dose aspirin is not associated with an increased risk of any type of ICB and is associated with a significantly decreased risk of SAH when used for ≥1 year. © 2017 American Academy of Neurology.

  20. Radiation dose and cancer risk from pediatric CT examinations on 64-slice CT: A phantom study

    International Nuclear Information System (INIS)

    Feng Shiting; Law, Martin Wai-Ming; Huang Bingsheng; Ng, Sherry; Li Ziping; Meng Quanfei; Khong, Pek-Lan

    2010-01-01

    Objective: To measure the radiation dose from CT scans in an anthropomorphic phantom using a 64-slice MDCT, and to estimate the associated cancer risk. Materials and methods: Organ doses were measured with a 5-year-old phantom and thermoluminescent dosimeters. Four protocols; head CT, thorax CT, abdomen CT and pelvis CT were studied. Cancer risks, in the form of lifetime attributable risk (LAR) of cancer incidence, were estimated by linear extrapolation using the organ radiation doses and the LAR data. Results: The effective doses for head, thorax, abdomen and pelvis CT, were 0.7 mSv, 3.5 mSv, 3.0 mSv, 1.3 mSv respectively. The organs with the highest dose were; for head CT, salivary gland (22.33 mGy); for thorax CT, breast (7.89 mGy); for abdomen CT, colon (6.62 mGy); for pelvis CT, bladder (4.28 mGy). The corresponding LARs for boys and girls were 0.015-0.053% and 0.034-0.155% respectively. The organs with highest LARs were; for head CT, thyroid gland (0.003% for boys, 0.015% for girls); for thorax CT, lung for boys (0.014%) and breast for girls (0.069%); for abdomen CT, colon for boys (0.017%) and lung for girls (0.016%); for pelvis CT, bladder for both boys and girls (0.008%). Conclusion: The effective doses from these common pediatric CT examinations ranged from 0.7 mSv to 3.5 mSv and the associated lifetime cancer risks were found to be up to 0.16%, with some organs of higher radiosensitivity including breast, thyroid gland, colon and lungs.

  1. Risk Factors and Dose-Effect Relationship for Mandibular Osteoradionecrosis in Oral and Oropharyngeal Cancer Patients

    International Nuclear Information System (INIS)

    Lee, Ik Jae; Koom, Woong Sub; Lee, Chang Geol; Kim, Yong Bae; Yoo, Sei Whan; Keum, Ki Chang; Kim, Gwi Eon; Choi, Eun Chang; Cha, In Ho

    2009-01-01

    Purpose: To analyze risk factors and the dose-effect relationship for osteoradionecrosis (ORN) of the mandible after radiotherapy of oral and oropharyngeal cancers. Materials and Methods: One-hundred ninety-eight patients with oral (45%) and oropharyngeal cancer (55%) who had received external radiotherapy between 1990 and 2000 were retrospectively reviewed. All patients had a dental evaluation before radiotherapy. The median radiation dose was 60 Gy (range, 16-75 Gy), and the median biologically effective dose for late effects (BED late ) in bone was 114 Gy 2 (range, 30-167 Gy 2 ). Results: The frequency of ORN was 13 patients (6.6%). Among patients with mandibular surgery, eight had ORN at the surgical site. Among patients without mandibular surgery, five patients had ORN on the molar area of the mandible. The median time to ORN was 22 months (range, 1-69 months). Univariate analysis revealed that mandibular surgery and Co-60 were significant risk factors for ORN (p = 0.01 and 0.04, respectively). In multivariate analysis, mandibular surgery was the most important factor (p = 0.001). High radiation doses over BED 102.6 Gy 2 (conventional dose of 54 Gy at 1.8 Gy/fraction) were also a significant factor for ORN (p = 0.008) and showed a positive dose-effect relationship in logistic regression (p = 0.04) for patients who had undergone mandibular surgery. Conclusions: Mandibular surgery was the most significant risk factor for ORN of mandible in oral and oropharyngeal cancers patients. A BED of 102.6 Gy 2 or higher to the mandible also significantly increases the risk of ORN.

  2. Information from the National Institute of Radiation Protection about radiation doses and radiation risks at x-ray screening

    International Nuclear Information System (INIS)

    1975-05-01

    This report gives a specification of data concerning radiation doses and risks at x-ray investigations of lungs. The dose estimations are principally based on measurements performed in 1974 by the National Institute of Radiation Protection. The radiation doses at x-ray screening are of that magnitude that the risk for acute radiation injuries is non-existent. At these low doses it has not either been able to prove that the radiation gives long-range effects as changes in the genes or cancer of late appearance. At considerable higher doses, more than tens of thousands of millirads, a risk of cancer appearance at a small part of all irradiated persons has been proved, based on the assumption that the cancer risk is proportional to the radiation dose. Cancer can thus occure at low radiation doses too. Because of the mass radiography in Sweden 1974 about twenty cases of cancer may appear in the future. (M.S.)

  3. Study of dose and relative risk of occupationally exposed individuals in interventional procedures

    International Nuclear Information System (INIS)

    Silveira Filho, Jose A.M.; Reis, Charlene O.; Taniguti, Lana T.; Pacifico, Leonardo C.; SaintYves, Thalis L.A.; Mecca, Fernando A.

    2012-01-01

    This paper estimates the occupational effective dose and the relative risk of leukemia and cancers of the digestive tract mortality through dose study of the most radiosensitive anatomical regions (lens, thyroid, chest and gonads) of the professionals involved in interventional gonad procedures. It was considered a cumulative exposure time of 10,000 hours, which is the occupational exposure time of an IOE in throughout his professional life. It was also considered that they always use Personal Protective Equipment (PPE). Mathematical models derived from epidemiological data contained in the BEIR V and in the IAEA’s TECDOC 870 are used to estimate the relative risk. The results show a significant increase in mortality risk for these types of cancer for individuals occupationally exposed to three different distances from the x-ray beam, and reinforces that radiation protection measures are essential. (author)

  4. Minimising the risk: reducing breast tissue dose in an adolescent female

    International Nuclear Information System (INIS)

    Thompson, Ann; Toe, Aimee; Ungureanu, Elena; Wolf, M.; Wirth, Andrew

    2005-01-01

    Breast cancer is amongst the leading radiation-associated, second malignancies that develop in patients after treatment for Hodgkin's disease. This risk is affected by two main factors: 1. The age of the patient at the time of radiotherapy; and 2. The dose received by the breast tissue The adolescent female thus faces an exceptionally high risk, as breast tissue at this age is undergoing rapid developmental growth and small doses of radiation exposure could be carcinogenic. This case report of a fifteen-year-old girl who received radiotherapy for Hodgkin's disease demonstrates how radiation therapists worked together with the radiation oncologists and medical physicists to provide an optimal treatment plan for a high-risk patient. Copyright (2005) Australian Institute of Radiography

  5. Effect of Radiotherapy Volume and Dose on Secondary Cancer Risk in Stage I Testicular Seminoma

    International Nuclear Information System (INIS)

    Zwahlen, Daniel R.; Martin, Jarad M.; Millar, Jeremy L.; Schneider, Uwe

    2008-01-01

    Purpose: To estimate and compare the secondary cancer risk (SCR) due to para-aortic (PA), dogleg field (DLF), or extensive field (EF) radiotherapy (RT) at different dose levels for Stage I testicular seminoma. Methods and Materials: The organ equivalent dose concept with a linear, plateau, and linear-exponential dose-response model was applied to the dose distributions to estimate the SCR. The dose distributions were calculated in a voxel-based anthropomorphic phantom. Three different three-dimensional plans were computed: PA, DLF, and EF. The plans were calculated with 6-MV photons and two opposed fields, using 20 Gy in 10 fractions. Results: The estimated cumulative SCR for a 75-year-old patient treated with PA-RT at age 35 was 23.3% (linear model), 20.9% (plateau model), and 20.8% (linear-exponential model) compared with 19.8% for the general population. Dependent on the model, PA-RT compared with DLF-RT reduced the SCR by 48-63% or 64-69% when normalized to EF-RT. For PA-RT, the linear dose-response model predicted a decrease of 45% in the SCR, using 20 Gy instead of 30 Gy; the linear-exponential dose-response model predicted no change in SCR. Conclusion: Our model suggested that the SCR after PA-RT for Stage I testicular seminoma is reduced by approximately one-half to two-thirds compared with DLF-RT, independent of the dose-response model. The SCR is expected to be equal or lower with 20 Gy than with 30 Gy. In the absence of mature patient data, the organ equivalent dose concept offers the best potential method of estimating the SCR when discussing treatment options with patients

  6. Long term results of a prospective dose escalation phase-II trial: Interstitial pulsed-dose-rate brachytherapy as boost for intermediate- and high-risk prostate cancer

    International Nuclear Information System (INIS)

    Lettmaier, Sebastian; Lotter, Michael; Kreppner, Stephan; Strnad, Annedore; Fietkau, Rainer; Strnad, Vratislav

    2012-01-01

    Purpose: We reviewed our seven year single institution experience with pulsed dose rate brachytherapy dose escalation study in patients with intermediate and high risk prostate cancer. Materials and methods: We treated a total of 130 patients for intermediate and high risk prostate cancer at our institution between 2000 and 2007 using PDR-brachytherapy as a boost after conformal external beam radiation therapy to 50.4 Gy. The majority of patients had T2 disease (T1c 6%, T2 75%, T3 19%). Seventy three patients had intermediate-risk and 53 patients had high-risk disease according to the D’Amico classification. The dose of the brachytherapy boost was escalated from 25 to 35 Gy – 33 pts. received 25 Gy (total dose 75 Gy), 63 pts. 30 Gy (total dose 80 Gy) and 34 pts. 35 Gy, (total dose 85 Gy) given in one session (dose per pulse was 0.60 Gy or 0.70 Gy/h, 24 h per day, night and day, with a time interval of 1 h between two pulses). PSA-recurrence-free survival according to Kaplan–Meier using the Phoenix definition of biochemical failure was calculated and also late toxicities according to Common Toxicity Criteria scale were assessed. Results: At the time of analysis with a median follow-up of 60 months biochemical control was achieved by 88% of patients – only 16/130 patients (12.3%) developed a biochemical relapse. Biochemical relapse free survival calculated according to Kaplan–Meier for all patients at 5 years was 85.6% (83.9% for intermediate-risk patients and 84.2% for high-risk patients) and at 9 years’ follow up it was 79.0%. Analysing biochemical relapse free survival separately for different boost dose levels, at 5 years it was 97% for the 35 Gy boost dose and 82% for the 25 and 30 Gy dose levels. The side effects of therapy were negligible: There were 18 cases (15%) of grade 1/2 rectal proctitis, one case (0.8%) of grade 3 proctitis, 18 cases (15%) of grade 1/2 cystitis, and no cases (0%) with dysuria grade 3. No patient had a bulbourethral

  7. Radioactivity Risk Assessment of Radon and Gamma Dose at One Uranium Tailings Pond in China

    Science.gov (United States)

    Lou, Yalong; Liu, Yong; Peng, Guowen; Zhao, Guodong; Zhang, Yan; Yang, Zhu

    2018-01-01

    A year-long monitoring of gamma radiation effective dose rate and radon concentration had been done in the reservoir area of one uranium tailings pond in Hunan province (The monitoring area included indoor and outdoor area of residential buildings and workshops, tailings dam slope). Afterwards, the annual effective radiation dose of the people in that radiation environment had been calculated based on the results of monitoring, as well as a radiation risk assessment. According to the assessment, gamma radiation effective dose rate and radon concentration in the monitoring area were low, and the annual effective radiation dose was far below the international standard (30mSv), which showed that the radiation would not put the people’s health at risk. However, the annual effective radiation dose of gamma was far above that of radon in the area of uranium tailings pond; therefore, it’s advisable to take quarantine measures in in the area of uranium tailings pond to keep the surrounding residents away from unnecessary ionizing radiation.

  8. Concord Grape Juice Polyphenols and Cardiovascular Risk Factors: Dose-Response Relationships

    Science.gov (United States)

    Blumberg, Jeffrey B.; Vita, Joseph A.; Chen, C. -Y. Oliver

    2015-01-01

    Pure fruit juices provide nutritional value with evidence suggesting some of their benefits on biomarkers of cardiovascular disease risk may be derived from their constituent polyphenols, particularly flavonoids. However, few data from clinical trials are available on the dose-response relationship of fruit juice flavonoids to these outcomes. Utilizing the results of clinical trials testing single doses, we have analyzed data from studies of 100% Concord grape juice by placing its flavonoid content in the context of results from randomized clinical trials of other polyphenol-rich foods and beverages describing the same outcomes but covering a broader range of intake. We selected established biomarkers determined by similar methods for measuring flow-mediated vasodilation (FMD), blood pressure, platelet aggregation, and the resistance of low density lipoprotein cholesterol (LDL) to oxidation. Despite differences among the clinical trials in the treatment, subjects, and duration, correlations were observed between the dose and FMD. Inverse dose-response relationships, albeit with lower correlation coefficients, were also noted for the other outcomes. These results suggest a clear relationship between consumption of even modest serving sizes of Concord grape juice, flavonoid intake, and effects on risk factors for cardiovascular disease. This approach to dose-response relationships may prove useful for testing other individual foods and beverages. PMID:26633488

  9. Estimation of effective dose and lifetime attributable risk from multiple head CT scans in ventriculoperitoneal shunted children

    International Nuclear Information System (INIS)

    Aw-Zoretic, J.; Seth, D.; Katzman, G.; Sammet, S.

    2014-01-01

    Purpose: The purpose of this review is to determine the averaged effective dose and lifetime attributable risk factor from multiple head computed tomography (CT) dose data on children with ventriculoperitoneal shunts (VPS). Method and materials: A total of 422 paediatric head CT exams were found between October 2008 and January 2011 and retrospectively reviewed. The CT dose data was weighted with the latest IRCP 103 conversion factor to obtain the effective dose per study and the averaged effective dose was calculated. Estimates of the lifetime attributable risk were also calculated from the averaged effective dose using a conversion factor from the latest BEIR VII report. Results: Our study found the highest effective doses in neonates and the lowest effective doses were observed in the 10–18 years age group. We estimated a 0.007% potential increase risk in neonates and 0.001% potential increased risk in teenagers over the base risk. Conclusion: Multiple head CTs in children equates to a slight potential increase risk in lifetime attributable risk over the baseline risk for cancer, slightly higher in neonates relative to teenagers. The potential risks versus clinical benefit must be assessed

  10. Dose-to-dose variations with single packages of counterfeit medicines and adulterated dietary supplements as a potential source of false negatives and inaccurate health risk assessments.

    Science.gov (United States)

    Venhuis, B J; Zwaagstra, M E; Keizers, P H J; de Kaste, D

    2014-02-01

    In this report, we show three examples of how the variability in dose units in single packages of counterfeit medicines and adulterated dietary supplements may contribute to a false negative screening result and inaccurate health risk assessments. We describe a counterfeit Viagra 100mg blister pack and a box of an instant coffee both containing dose units with and without an active pharmaceutical ingredient (API). We also describe a purportedly herbal slimming product with capsules that mutually differed in API and impurities. The adulterated dietary supplements contained sibutramine, benzyl-sibutramine, N-desmethyl-sibutramine (DMS), N,N-didesmethyl-sibutramine (DDMS) and several other related impurities. Counterfeit medicines and adulterated dietary supplements are a health risk because their quality is unreliable. Health risks are even greater when such unreliability extends to fundamental differences between dose units in one package. Because dose-to-dose variability for these products is unpredictable, the confidence interval of a sample size is unknown. Consequently, the analyses of a selection of dose units may not be representative for the package. In the worst case, counterfeit or unauthorised medicines are not recognised as such or a health risk is not identified. In order to reduce erroneous results particular care should be taken when analysing a composite of dose units, when finding no API in a dietary supplement and when finding conformity in a suspect counterfeit medicine. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. A long-term risk-benefit analysis of low-dose aspirin in primary prevention.

    Science.gov (United States)

    Wu, I-Chen; Hsieh, Hui-Min; Yu, Fang-Jung; Wu, Meng-Chieh; Wu, Tzung-Shiun; Wu, Ming-Tsang

    2016-02-01

    The long-term risk-benefit effect of occasional and regular use of low-dose aspirin (≤ 100 mg per day) in primary prevention of vascular diseases and cancers was calculated. One representative database of 1 000 000 participants from Taiwan's National Health Insurance scheme in 1997-2000 was used. The potential study subjects were those aged 30-95 years, were found not to have been prescribed aspirin before 1 January 2000, but to have first been prescribed low-dose aspirin (≤ 100 mg per day) after that date and were followed up to 31 December 2009. Participants prescribed low-dose aspirin risk. A total of 1720 pairs were analysed. During the study period, haemorrhage and ischaemia occurred in 25 (1·45%) and 67 participants (3·90%) in occasional users and 69 (4·01%) and 100 participants (5·81%) in regular users, whereas cancer occurred in 32 participants (1·86%) in occasional users and 26 participants (1·51%) in regular users. The crude and adjusted net clinical risks of low-dose aspirin use between the two frequency of users (≥ 80% vs. prevention against major vascular diseases and cancer. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.

  12. Analysis of dose and risk associated with the use of backscatter vans

    International Nuclear Information System (INIS)

    Correa, Samanda C.A.; Aquino, Josilto O.; Silva, Ademir X.

    2011-01-01

    In recent years, imaging technology using radiation has been gaining in importance for the screening of persons for security reasons and in order to detect contraband. And currently, new X-ray detection technologies have been introduced such as the Backscatter Van. The Backscatter Van is used in port and border security, force protection, urban surveillance, and other critical security applications in order to seize drugs, explosives, and more. The system is mobile, affordable and the faster, more effective, and less expensive than any mobile screening solution in the marketplace. However, although the application of this equipment in the national security area is indeed relevant, its use has caused a great deal of controversy, especially with regard to the doses absorbed and to the cancer induction risk associated with these exposures. The aim of this study is to use the Monte Carlo MCNPX code and the male adult voxel (MAX) and female adult voxel (FAX) phantoms, to evaluate the absorbed dose, effective dose and cancer induction risk values associated with the exposures of individuals submitted to Backscatter Van. The effective dose values were calculated as recommended by the new ICRP 103 and the cancer induction risk values were estimated through the BEIR VII document. (author)

  13. Analysis of dose and risk associated with the use of backscatter vans

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Samanda C.A.; Aquino, Josilto O., E-mail: scorrea@cnen.gov.b, E-mail: josilto@cnen.gov.b [Comissao Nacional de Energia Nuclear (DIAPI/CGMI/CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao Geral de Instalacoes Medicas e Industriais. Div. de Aplicacoes Industriais; Souza, Edmilson M., E-mail: emonteiro@nuclear.ufrj.b [Centro Universitario Estadual da Zona Oeste (CAPI/UEZO), Rio de Janeiro, RJ (Brazil); Silva, Ademir X., E-mail: ademir@con.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2011-07-01

    In recent years, imaging technology using radiation has been gaining in importance for the screening of persons for security reasons and in order to detect contraband. And currently, new X-ray detection technologies have been introduced such as the Backscatter Van. The Backscatter Van is used in port and border security, force protection, urban surveillance, and other critical security applications in order to seize drugs, explosives, and more. The system is mobile, affordable and the faster, more effective, and less expensive than any mobile screening solution in the marketplace. However, although the application of this equipment in the national security area is indeed relevant, its use has caused a great deal of controversy, especially with regard to the doses absorbed and to the cancer induction risk associated with these exposures. The aim of this study is to use the Monte Carlo MCNPX code and the male adult voxel (MAX) and female adult voxel (FAX) phantoms, to evaluate the absorbed dose, effective dose and cancer induction risk values associated with the exposures of individuals submitted to Backscatter Van. The effective dose values were calculated as recommended by the new ICRP 103 and the cancer induction risk values were estimated through the BEIR VII document. (author)

  14. Low dose radiation and ALARA: the potential risks to patients and staff from alpha-therapy

    International Nuclear Information System (INIS)

    Priest, N.D.

    2014-01-01

    This year a new drug containing radium-223, an alpha-emitting radionuclide, was approved for use by the US Food and Drug Administration for the palliative treatment of advanced prostate cancer metastases. Other drugs containing short-lived alpha-emitters are on clinical trial in Europe. Commonly, these employ a radionuclide attached to an antibody that specifically targets tumor cells to produce a highly localized radio-therapeutic dose to the tumor. However, normal tissues within the body will also be irradiated, albeit sometimes at low dose, and the question arises as to whether this presents a significant additional risk to the patient. Similarly, medical staff that handle these radionuclides could receive intakes of the radionuclides. What is the risk to staff? To assess the risk resulting from small tissue alpha-doses the toxicological, both human and animal, database was re-examined. The results of 20 epidemiological and toxicological studies with alpha-emitting radionuclides were analysed. In all cases a polynomial function provided a better fit to the data than a linear, no thresholds function. Also, in 19 cases a threshold dose below which no cancer is seen was indicated. The position of this threshold varied according to cancer type, but was typically in the range 0.1 to 1.0Gy of tissue dose - with a mean of 0.5Gy. It is concluded that alpha-radiation induced tumorogenesis is a threshold response and that as long as tissue doses are kept below these thresholds no additional cancers would be seen in either patients receiving alpha-therapy or in staff exposed to 'spilt' radionuclide. The presence of thresholds questions the appropriateness of current ALARA practices that are mostly used to drive occupational alpha-radiation exposures to as close to zero as possible. (author)

  15. Low dose radiation and ALARA: the potential risks to patients and staff from alpha-therapy

    Energy Technology Data Exchange (ETDEWEB)

    Priest, N.D. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

    2014-07-01

    This year a new drug containing radium-223, an alpha-emitting radionuclide, was approved for use by the US Food and Drug Administration for the palliative treatment of advanced prostate cancer metastases. Other drugs containing short-lived alpha-emitters are on clinical trial in Europe. Commonly, these employ a radionuclide attached to an antibody that specifically targets tumor cells to produce a highly localized radio-therapeutic dose to the tumor. However, normal tissues within the body will also be irradiated, albeit sometimes at low dose, and the question arises as to whether this presents a significant additional risk to the patient. Similarly, medical staff that handle these radionuclides could receive intakes of the radionuclides. What is the risk to staff? To assess the risk resulting from small tissue alpha-doses the toxicological, both human and animal, database was re-examined. The results of 20 epidemiological and toxicological studies with alpha-emitting radionuclides were analysed. In all cases a polynomial function provided a better fit to the data than a linear, no thresholds function. Also, in 19 cases a threshold dose below which no cancer is seen was indicated. The position of this threshold varied according to cancer type, but was typically in the range 0.1 to 1.0Gy of tissue dose - with a mean of 0.5Gy. It is concluded that alpha-radiation induced tumorogenesis is a threshold response and that as long as tissue doses are kept below these thresholds no additional cancers would be seen in either patients receiving alpha-therapy or in staff exposed to 'spilt' radionuclide. The presence of thresholds questions the appropriateness of current ALARA practices that are mostly used to drive occupational alpha-radiation exposures to as close to zero as possible. (author)

  16. Dose related risk and effect assessment model (DREAM) -- A more realistic approach to risk assessment of offshore discharges

    International Nuclear Information System (INIS)

    Johnsen, S.; Furuholt, E.

    1995-01-01

    Risk assessment of discharges from offshore oil and gas production to the marine environment features determination of potential environmental concentration (PEC) levels and no observed effect concentration (NOEC) levels. The PEC values are normally based on dilution of chemical components in the actual discharge source in the recipient, while the NOEC values are determined by applying a safety factor to acute toxic effects from laboratory tests. The DREAM concept focuses on realistic exposure doses as function of contact time and dilution, rather than fixed exposure concentrations of chemicals in long time exposure regimes. In its present state, the DREAM model is based on a number of assumptions with respect to the link between real life exposure doses and effects observed in laboratory tests. A research project has recently been initiated to develop the concept further, with special focus on chronic effects of different chemical compounds on the marine ecosystem. One of the questions that will be addressed is the link between exposure time, dose, concentration and effect. Validation of the safety factors applied for transforming acute toxic data into NOEC values will also be included. The DREAM model has been used by Statoil for risk assessment of discharges from new and existing offshore oil and gas production fields, and has been found to give a much more realistic results than conventional risk assessment tools. The presentation outlines the background for the DREAM approach, describes the model in its present state, discusses further developments and applications, and shows a number of examples on the performance of DREAM

  17. Metformin decreases lung cancer risk in diabetic patients in a dose-dependent manner.

    Science.gov (United States)

    Tsai, Ming-Ju; Yang, Chih-Jen; Kung, Ya-Ting; Sheu, Chau-Chyun; Shen, Yu-Ting; Chang, Pi-Yu; Huang, Ming-Shyan; Chiu, Herng-Chia

    2014-11-01

    Higher risk of lung cancer has been noted in patients with type 2 diabetes mellitus (DM). Some observational studies have shown a reduced risk of lung cancer in DM patients taking metformin, but a dose-response relationship has never been reported. The aim of this study is to exam the association between the dose of metformin and the incidence of lung cancer in a Chinese population. The dataset used for this nationwide population-based study is a cohort of 1 million subjects randomly sampled from individuals enrolled in the Taiwan National Health Insurance system. We enrolled all subjects with newly diagnosed type 2 DM between 1997 and 2007. Subjects with a diagnosis of neoplasm before DM diagnosis, those using metformin before DM diagnosis, those with polycystic ovary syndrome, and those with a DM diagnosis before their 15 years of age were excluded. The demographic data and duration, cumulative dose and intensity of metformin use were compared between patients developing lung cancer and those without lung cancer. Totally, 47,356 subjects were identified. After adjusting for age, gender, and modified Charlson Comorbidity Index score, the utilization of metformin was an independent protecting factor, and the risk of developing lung cancer decreased progressively with either the higher cumulative dose or the higher intensity of metformin use. This study revealed that the use of metformin decreased the risk of lung cancer in a dose-dependent manner in patients with type 2 DM. The chemo-preventive effect of metformin deserves further study. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Low Birth Weight, Cumulative Obesity Dose, and the Risk of Incident Type 2 Diabetes

    OpenAIRE

    Feng, Cindy; Osgood, Nathaniel D.; Dyck, Roland F.

    2018-01-01

    Background. Obesity history may provide a better understanding of the contribution of obesity to T2DM risk. Methods. 17,634 participants from the 1958 National Child Development Study were followed from birth to 50 years. Cumulative obesity dose, a measure of obesity history, was calculated by subtracting the upper cut-off of the normal BMI from the actual BMI at each follow-up and summing the areas under the obesity dose curve. Hazard ratios (HRs) for diabetes were calculated using Cox regre...

  19. The risk equivalent of an exposure to-, versus a dose of radiation

    International Nuclear Information System (INIS)

    Bond, V.P.

    1986-01-01

    The long-term potential carcinogenic effects of low-level exposure (LLE) are addressed. The principal point discussed is linear, no-threshold dose-response curve. That the linear no-threshold, or proportional relationship is widely used is seen in the way in which the values for cancer risk coefficients are expressed - in terms of new cases, per million persons exposed, per year, per unit exposure or dose. This implies that the underlying relationship is proportional, i.e., ''linear, without threshold''. 12 refs., 9 figs., 1 tab

  20. Lifetime radiation risks from low-dose rate radionuclides in beagles

    International Nuclear Information System (INIS)

    Goldman, M.; Rosenblatt, L.S.

    1985-01-01

    One of the largest, long-term (25-yr) animal studies on the effects of low-dose internal irradiation is almost completed. Some 335 beagles were given continuous exposure to graded 90 Sr [low linear energy transfer (LET)] in their diets (D-dogs) through adulthood. A second group (R-dogs) was given fractionated doses of 225 Ra (high LET) as young adults. A third group of 44 was given a single injection of 90 Sr as adults (S-dogs) to compare single to continuous dosages. All dogs were followed through their lifetimes. Only one of the 848 dogs is still alive. The animals were whole-body counted over their entire life span and were examined frequently for assessment of medical status. There were no acute radiation lethalities. Analyses of the large data base from these dogs have begun and preliminary indications are that 90 Sr, which was tested over a 1500-fold skeletal dose rate range, does not cause significant life shortening at average accumulation skeletal doses of ∼2500 rads (25 Gy) and that a curvilinear dose response curve for life shortening was seen at higher accumulation doses. The data will be discussed in terms of modern epidemiological concepts and quantifications will be related to certain parameters of human risk from acute or chronic radiation exposures

  1. Risk ratios for use in establishing dose limits for occupational exposure to radiation

    International Nuclear Information System (INIS)

    Metcalf, P.E.; Winkler, B.C.

    1980-01-01

    Dose limits for occupational exposure to radiation may be established by comparing the associated mortality risk with apparently accepted levels of industrial mortality risk due to conventional hazards. Average levels of industrial mortality risk rates are frequently quoted and used in such comparisons. However, within particular occupations or industries certain groups of workers will be exposed to higher levels of risk than the average, again an apparently accepted situation. A study has been made of the ratios of maximum to average industrial mortality risk currently experienced in some South African industries. Such a ratio may be used to assess the acceptability of maximum individual-to-average exposures in particular groups of exposed individuals. (author)

  2. Effective dose and cancer risk in PET/CT exams; Dose efetiva e risco de cancer em exames de PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Gabriella M.; Sa, Lidia Vasconcellos de, E-mail: montezano@ird.gov.br, E-mail: Iidia@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    Due to the use of radiopharmaceutical positron-emitting in PET exam and realization of tomography by x-ray transmission in CT examination, an increase of dose with hybrid PET/CT technology is expected. However, differences of doses have been reported in many countries for the same type of procedure. It is expected that the dose is an influent parameter to standardize the protocols of PET/CT. This study aimed to estimate the effective doses and absorbed in 65 patients submitted to oncological Protocol in a nuclear medicine clinic in Rio de Janeiro, considering the risk of induction of cancer from the scan. The CT exam-related doses were estimated with a simulator of PMMA and simulated on the lmPACT resistance, which for program effective dose, were considered the weight factors of the lCRP 103. The PET exam doses were estimated by multiplying the activity administered to the patient with the ICRP dose 80 factors. The radiological risk for cancer incidence were estimated according to the ICRP 103. The results showed that the effective dose from CT exam is responsible for 70% of the effective total in a PET/CT scan. values of effective dose for the PET/CT exam reached average values of up to 25 mSv leading to a risk of 2, 57 x 10{sup -4}. Considering that in staging of oncological diseases at least four tests are performed annually, the total risk comes to 1,03x 10{sup -3}.

  3. Dose to the Developing Dentition During Therapeutic Irradiation: Organ at Risk Determination and Clinical Implications

    International Nuclear Information System (INIS)

    Thompson, Reid F.; Schneider, Ralf A.; Albertini, Francesca; Lomax, Antony J.; Ares, Carmen; Goitein, Gudrun; Hug, Eugen B.

    2013-01-01

    Purpose: Irradiation of pediatric facial structures can cause severe impairment of permanent teeth later in life. We therefore focused on primary and permanent teeth as organs at risk, investigating the ability to identify individual teeth in children and infants and to correlate dose distributions with subsequent dental toxicity. Methods and Materials: We retrospectively reviewed 14 pediatric patients who received a maximum dose >20 Gy(relative biological effectiveness, RBE) to 1 or more primary or permanent teeth between 2003 and 2009. The patients (aged 1-16 years) received spot-scanning proton therapy with 46 to 66 Gy(RBE) in 23 to 33 daily fractions for a variety of tumors, including rhabdomyosarcoma (n=10), sarcoma (n=2), teratoma (n=1), and carcinoma (n=1). Individual teeth were contoured on axial slices from planning computed tomography (CT) scans. Dose-volume histogram data were retrospectively obtained from total calculated delivered treatments. Dental follow-up information was obtained from external care providers. Results: All primary teeth and permanent incisors, canines, premolars, and first and second molars were identifiable on CT scans in all patients as early as 1 year of age. Dose-volume histogram analysis showed wide dose variability, with a median 37 Gy(RBE) per tooth dose range across all individuals, and a median 50 Gy(RBE) intraindividual dose range across all teeth. Dental follow-up revealed absence of significant toxicity in 7 of 10 patients but severe localized toxicity in teeth receiving >20 Gy(RBE) among 3 patients who were all treated at <4 years of age. Conclusions: CT-based assessment of dose distribution to individual teeth is feasible, although delayed calcification may complicate tooth identification in the youngest patients. Patterns of dental dose exposure vary markedly within and among patients, corresponding to rapid dose falloff with protons. Severe localized dental toxicity was observed in a few patients receiving the

  4. Dose and risk evaluation to the thyroid gland in intra-oral dental radiology

    International Nuclear Information System (INIS)

    Souza, Edmilson M.; Lima, Marco A.F.; Kelecom, Alphonse; Correa, Samanda C.A.; Silva, Ademir X.; Brito, Alan

    2008-01-01

    Intra-oral technique is one of the most frequently used procedures of dental radiology, allowing the detection of a variety of dental anomalies such as caries, dental trauma and periodontal lesions, while exposing patients to relatively low doses of radiation. However, although the adverse effects of doses generated by dental radiology are essentially stochastic, a number of epidemiological studies have provided evidence of an increased risk of thyroid tumors for dental radiography. Many studies have measured doses of radiation for dental radiography, but only a few have estimated thyroid dose. Furthermore, most of the studies on dose evaluation in dental radiology are based on standardized calculation phantoms, which neglect the variance of the patient size or even sex. The purpose of this study is to use the Monte Carlo code MCNPX and the FAX (Female Adult voXel) and MAX (Male Adult voXel) phantoms to investigate how absorbed doses to the thyroid gland in intraoral dental examinations vary in female and male patients. The lifetime cancer incidence attributable to dental examinations were estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The phantoms study proved a useful trial for detecting the radiation dose to the thyroid gland and conclusively supported that the anatomy may be regarded as an influencing factor in radiation dose received during dental examination. Finally, the results have also confirmed that the association of the MCNPX code and the MAX and FAX phantoms is very useful in dosimetric studies on radiographic examinations of female and male patients. (author)

  5. Development of Graphical User Interface for ARRBOD (Acute Radiation Risk and BRYNTRN Organ Dose Projection)

    Science.gov (United States)

    Kim, Myung-Hee; Hu, Shaowen; Nounu, Hatem N.; Cucinotta, Francis A.

    2010-01-01

    The space radiation environment, particularly solar particle events (SPEs), poses the risk of acute radiation sickness (ARS) to humans; and organ doses from SPE exposure may reach critical levels during extra vehicular activities (EVAs) or within lightly shielded spacecraft. NASA has developed an organ dose projection model using the BRYNTRN with SUMDOSE computer codes, and a probabilistic model of Acute Radiation Risk (ARR). The codes BRYNTRN and SUMDOSE, written in FORTRAN, are a Baryon transport code and an output data processing code, respectively. The ARR code is written in C. The risk projection models of organ doses and ARR take the output from BRYNTRN as an input to their calculations. BRYNTRN code operation requires extensive input preparation. With a graphical user interface (GUI) to handle input and output for BRYNTRN, the response models can be connected easily and correctly to BRYNTRN in friendly way. A GUI for the Acute Radiation Risk and BRYNTRN Organ Dose (ARRBOD) projection code provides seamless integration of input and output manipulations, which are required for operations of the ARRBOD modules: BRYNTRN, SUMDOSE, and the ARR probabilistic response model. The ARRBOD GUI is intended for mission planners, radiation shield designers, space operations in the mission operations directorate (MOD), and space biophysics researchers. The ARRBOD GUI will serve as a proof-of-concept example for future integration of other human space applications risk projection models. The current version of the ARRBOD GUI is a new self-contained product and will have follow-on versions, as options are added: 1) human geometries of MAX/FAX in addition to CAM/CAF; 2) shielding distributions for spacecraft, Mars surface and atmosphere; 3) various space environmental and biophysical models; and 4) other response models to be connected to the BRYNTRN. The major components of the overall system, the subsystem interconnections, and external interfaces are described in this

  6. Radiation doses and risks to neonates undergoing common radiographic examinations in the neonatal intensive care unit

    International Nuclear Information System (INIS)

    McParland, B.J.; Lee, R.

    1996-01-01

    Neonates in the-Neonatal Intensive Care Unit (NICU) can receive large numbers of radiographs owing to the clinical conditions they may present. More neonatal radiation dosimetry data are required for three fundamental reasons: (1.) to aid in the establishment of reference dose levels for interinstitutional comparisons; (2.) to improve childhood cancer risk estimates following neonatal exposure; and (3.) to indicate appropriate directions for dose reduction. This paper describes an investigation of two different NICU radiological techniques with significantly different neonate doses. While patient-matched images taken with both techniques were assessed in a blind review, this component of the study is beyond the scope of this paper and is not discussed here. (author)

  7. Intensity-Modulated Radiotherapy for Craniospinal Irradiation: Target Volume Considerations, Dose Constraints, and Competing Risks

    International Nuclear Information System (INIS)

    Parker, William; Filion, Edith; Roberge, David; Freeman, Carolyn R.

    2007-01-01

    Purpose: To report the results of an analysis of dose received to tissues and organs outside the target volume, in the setting of spinal axis irradiation for the treatment of medulloblastoma, using three treatment techniques. Methods and Materials: Treatment plans (total dose, 23.4 Gy) for a standard two-dimensional (2D) technique, a three-dimensional (3D) technique using a 3D imaging-based target volume, and an intensity-modulated radiotherapy (IMRT) technique, were compared for 3 patients in terms of dose-volume statistics for target coverage, as well as organ at risk (OAR) and overall tissue sparing. Results: Planning target volume coverage and dose homogeneity was superior for the IMRT plans for V 95% (IMRT, 100%; 3D, 96%; 2D, 98%) and V 107% (IMRT, 3%; 3D, 38%; 2D, 37%). In terms of OAR sparing, the IMRT plan was better for all organs and whole-body contour when comparing V 10Gy , V 15Gy , and V 20Gy . The 3D plan was superior for V 5Gy and below. For the heart and liver in particular, the IMRT plans provided considerable sparing in terms of V 10Gy and above. In terms of the integral dose, the IMRT plans were superior for liver (IMRT, 21.9 J; 3D, 28.6 J; 2D, 38.6 J) and heart (IMRT, 9 J; 3D, 14.1J; 2D, 19.4 J), the 3D plan for the body contour (IMRT, 349 J; 3D, 337 J; 2D, 555 J). Conclusions: Intensity-modulated radiotherapy is a valid treatment option for spinal axis irradiation. We have shown that IMRT results in sparing of organs at risk without a significant increase in integral dose

  8. Impact of imaging approach on radiation dose and associated cancer risk in children undergoing cardiac catheterization.

    Science.gov (United States)

    Hill, Kevin D; Wang, Chu; Einstein, Andrew J; Januzis, Natalie; Nguyen, Giao; Li, Jennifer S; Fleming, Gregory A; Yoshizumi, Terry K

    2017-04-01

    To quantify the impact of image optimization on absorbed radiation dose and associated risk in children undergoing cardiac catheterization. Various imaging and fluoroscopy system technical parameters including camera magnification, source-to-image distance, collimation, antiscatter grids, beam quality, and pulse rates, all affect radiation dose but have not been well studied in younger children. We used anthropomorphic phantoms (ages: newborn and 5 years old) to measure surface radiation exposure from various imaging approaches and estimated absorbed organ doses and effective doses (ED) using Monte Carlo simulations. Models developed in the National Academies' Biological Effects of Ionizing Radiation VII report were used to compare an imaging protocol optimized for dose reduction versus suboptimal imaging (+20 cm source-to-image-distance, +1 magnification setting, no collimation) on lifetime attributable risk (LAR) of cancer. For the newborn and 5-year-old phantoms, respectively ED changes were as follows: +157% and +232% for an increase from 6-inch to 10-inch camera magnification; +61% and +59% for a 20 cm increase in source-to-image-distance; -42% and -48% with addition of 1-inch periphery collimation; -31% and -46% with removal of the antiscatter grid. Compared with an optimized protocol, suboptimal imaging increased ED by 2.75-fold (newborn) and fourfold (5 years old). Estimated cancer LAR from 30-min of posteroanterior fluoroscopy using optimized versus suboptimal imaging, respectively was 0.42% versus 1.23% (newborn female), 0.20% versus 0.53% (newborn male), 0.47% versus 1.70% (5-year-old female) and 0.16% versus 0.69% (5-year-old male). Radiation-related risks to children undergoing cardiac catheterization can be substantial but are markedly reduced with an optimized imaging approach. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Cumulative effective dose and cancer risk for pediatric population in repetitive full spine follow-up imaging: How micro dose is the EOS microdose protocol?

    Science.gov (United States)

    Law, Martin; Ma, Wang-Kei; Lau, Damian; Cheung, Kenneth; Ip, Janice; Yip, Lawrance; Lam, Wendy

    2018-04-01

    To evaluate and to obtain analytic formulation for the calculation of the effective dose and associated cancer risk using the EOS microdose protocol for scoliotic pediatric patients undergoing full spine imaging at different age of exposure; to demonstrate the microdose protocol capable of delivering lesser radiation dose and hence of further reducing cancer risk induction when compared with the EOS low dose protocol; to obtain cumulative effective dose and cancer risk for both genders scoliotic pediatrics of US and Hong Kong population using the microdose protocol. Organ absorbed doses of full spine exposed scoliotic pediatric patients have been simulated with the use of EOS microdose protocol imaging parameters input to the Monte Carlo software PCXMC. Gender and age specific effective dose has been calculated with the simulated organ absorbed dose using the ICRP-103 approach. The associated radiation induced cancer risk, expressed as lifetime attributable risk (LAR), has been estimated according to the method introduced in the Biological Effects of Ionizing Radiation VII report. Values of LAR have been estimated for scoliotic patients exposed repetitively during their follow up period at different age for US and Hong Kong population. The effective doses of full spine imaging with simultaneous posteroanterior and lateral projection for patients exposed at the age between 5 and 18 years using the EOS microdose protocol have been calculated within the range of 2.54-14.75 μSv. The corresponding LAR for US and Hong Kong population was ranged between 0.04 × 10 -6 and 0.84 × 10 -6 . Cumulative effective dose and cancer risk during follow-up period can be estimated using the results and are of information to patients and their parents. With the use of computer simulation and analytic formulation, we obtained the cumulative effective dose and cancer risk at any age of exposure for pediatric patients of US and Hong Kong population undergoing repetitive

  10. [Doses to organs at risk in conformational radiotherapy and stereotaxic irradiation: The heart].

    Science.gov (United States)

    Vandendorpe, B; Servagi Vernat, S; Ramiandrisoa, F; Bazire, L; Kirova, Y M

    2017-10-01

    Radiation therapy of breast cancer, Hodgkin lymphoma, lung cancer and others thoracic irradiations induce an ionizing radiation dose to the heart. Irradiation of the heart, associated with patient cardiovascular risk and cancer treatment-induced cardiotoxicity, increase cardiovascular mortality. The long survival after breast or Hodgkin lymphoma irradiation requires watching carefully late treatment toxicity. The over-risk of cardiac events is related to the dose received by the heart and the irradiated cardiac volume. The limitation of cardiac irradiation should be a priority in the planning of thoracic irradiations. Practices have to be modified, using modern techniques to approach of the primary objective of radiotherapy which is to optimize the dose to the target volume, sparing healthy tissues, in this case the heart. We have reviewed the literature on cardiac toxicity induced by conformational tridimensional radiation therapy, intensity-modulated radiation therapy or stereotactic body radiation therapy, in order to evaluate the possibilities to limit cardiotoxicity. Finally, we summarise the recommendations on dose constraints to the heart and coronary arteries. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  11. Analysis of the risk factors for exposure of the lung to low irradiation doses

    International Nuclear Information System (INIS)

    Hogeweg, B.

    1986-02-01

    In this report a description is presented of the risk factors for induction of lungtumours. The contribution of natural radioactivity from uranium and thorium to the lungs is mainly caused by inhalation of alpha-emitting radon and thorium daughter products. Apart from exposure by inhalation the lungs are also exposed to external radiation. For internal as well as external exposure a value of 10 -3 lungcancers per Sv lung dose equivalence is found to be acceptable for the riskfactor. (Auth.)

  12. Low doses of ionizing radiation and risk of cardiovascular disease: A review of epidemiological studies

    International Nuclear Information System (INIS)

    Metz-Flamant, C.; Bonaventure, A.; Tirmarche, M.; Laurier, D.; Bernier, M.O.; Milliat, F.

    2009-01-01

    Background While cardiovascular risks associated with high level of ionizing radiation are well-established, long-term effects of low and medium levels of exposure, between 0 and 5 gray (Gy), on the cardiovascular system are debated. Methods Available literature was reviewed considering various populations, such as survivors of atomic bombs, nuclear workers, Chernobyl liquidators, radiologists and radiological technologists and patients exposed for medical reasons. Results A significant increased risk of cardiovascular diseases associated with low doses of ionizing radiation was observed in 13 studies among the 27 analyzed. The ischemic heart diseases risk was detailed in 16 studies and seven of them showed a significant increase. The cerebrovascular risk was significantly increased in five studies among the 12 considered. Conclusion Some epidemiological and experimental data are clearly in favour of an increased cardiovascular risk associated with exposure to low doses. However, given the multi-factorial origin of cardiovascular diseases and the lack of a clear pathophysiologic mechanism, epidemiological results have to be carefully interpreted. Further research should be conducted in this area. (authors)

  13. Dose and risk assessment approach for the Fernald CERCLA D ampersand D Project

    International Nuclear Information System (INIS)

    Throckmorton, J.D.; Clark, T.R.; Waligora, S.J. Jr.; Haaker, R.F.

    1994-01-01

    At the Fernald Environmental Management Project (FEMP) the uranium processing facilities used from the 1952 through 1989 are near or beyond their intended design life. These current conditions present an increasing probability for future releases of hazardous substances to the environment. To support a decision by the U.S. Department of Energy (DOE) and the Environmental Protection Agency (EPA) to remediate the buildings, a dose and risk assessment was performed to determine the extent of exposure that would be associated with the controlled decontamination and dismantlement (D ampersand D) of the Fernald facilities. A conceptual risk assessment model was developed, with exposure mechanisms and associated pathways for each potential receptor. The three receptor groups were defined as: the remediation workers, other on-site workers (those not performing D ampersand D), and off-site residents. For use in the conceptual model, an airborne source term was developed through process knowledge, other historical information and data, and air sample data from within the facilities. Individual and collective doses and risks were developed for each receptor and for each population group. The risk assessment demonstrated that all exposures resulting from the action would be within the acceptable DOE administrative control level of 2.0 rem per year for occupational workers and the acceptable EPA risk range from 10 -6 to 10 -4 for the general public

  14. Quantifying the dose-response of walking in reducing coronary heart disease risk: meta-analysis.

    Science.gov (United States)

    Zheng, Henry; Orsini, Nicola; Amin, Janaki; Wolk, Alicja; Nguyen, Van Thi Thuy; Ehrlich, Fred

    2009-01-01

    The evidence for the efficacy of walking in reducing the risk of and preventing coronary heart disease (CHD) is not completely understood. This meta-analysis aimed to quantify the dose-response relationship between walking and CHD risk reduction for both men and women in the general population. Studies on walking and CHD primary prevention between 1954 and 2007 were identified through Medline, SportDiscus and the Cochrane Database of Systematic Reviews. Random-effect meta-regression models were used to pool the relative risks from individual studies. A total of 11 prospective cohort studies and one randomized control trial study met the inclusion criteria, with 295,177 participants free of CHD at baseline and 7,094 cases at follow-up. The meta-analysis indicated that an increment of approximately 30 min of normal walking a day for 5 days a week was associated with 19% CHD risk reduction (95% CI = 14-23%; P-heterogeneity = 0.56; I (2) = 0%). We found no evidence of heterogeneity between subgroups of studies defined by gender (P = 0.67); age of the study population (P = 0.52); or follow-up duration (P = 0.77). The meta-analysis showed that the risk for developing CHD decreases as walking dose increases. Walking should be prescribed as an evidence-based effective exercise modality for CHD prevention in the general population.

  15. A method to dynamically balance intensity modulated radiotherapy dose between organs-at-risk

    International Nuclear Information System (INIS)

    Das, Shiva K.

    2009-01-01

    The IMRT treatment planning process typically follows a path that is based on the manner in which the planner interactively adjusts the target and organ-at-risk (OAR) constraints and priorities. The time-intensive nature of this process restricts the planner from fully understanding the dose trade-off between structures, making it unlikely that the resulting plan fully exploits the extent to which dose can be redistributed between anatomical structures. Multiobjective Pareto optimization has been used in the past to enable the planner to more thoroughly explore alternatives in dose trade-off by combining pre-generated Pareto optimal solutions in real time, thereby potentially tailoring a plan more exactly to requirements. However, generating the Pareto optimal solutions can be nonintuitive and computationally time intensive. The author presents an intuitive and fast non-Pareto approach for generating optimization sequences (prior to planning), which can then be rapidly combined by the planner in real time to yield a satisfactory plan. Each optimization sequence incrementally reduces dose to one OAR at a time, starting from the optimization solution where dose to all OARs are reduced with equal priority, until user-specified target coverage limits are violated. The sequences are computationally efficient to generate, since the optimization at each position along a sequence is initiated from the end result of the previous position in the sequence. The pre-generated optimization sequences require no user interaction. In real time, a planner can more or less instantaneously visualize a treatment plan by combining the dose distributions corresponding to user-selected positions along each of the optimization sequences (target coverage is intrinsically maintained in the combination). Interactively varying the selected positions along each of the sequences enables the planner to rapidly understand the nature of dose trade-off between structures and, thereby, arrive at a

  16. The current state of knowledge on the use of the benchmark dose concept in risk assessment.

    Science.gov (United States)

    Sand, Salomon; Victorin, Katarina; Filipsson, Agneta Falk

    2008-05-01

    This review deals with the current state of knowledge on the use of the benchmark dose (BMD) concept in health risk assessment of chemicals. The BMD method is an alternative to the traditional no-observed-adverse-effect level (NOAEL) and has been presented as a methodological improvement in the field of risk assessment. The BMD method has mostly been employed in the USA but is presently given higher attention also in Europe. The review presents a number of arguments in favor of the BMD, relative to the NOAEL. In addition, it gives a detailed overview of the several procedures that have been suggested and applied for BMD analysis, for quantal as well as continuous data. For quantal data the BMD is generally defined as corresponding to an additional or extra risk of 5% or 10%. For continuous endpoints it is suggested that the BMD is defined as corresponding to a percentage change in response relative to background or relative to the dynamic range of response. Under such definitions, a 5% or 10% change can be considered as default. Besides how to define the BMD and its lower bound, the BMDL, the question of how to select the dose-response model to be used in the BMD and BMDL determination is highlighted. Issues of study design and comparison of dose-response curves and BMDs are also covered. Copyright (c) 2007 John Wiley & Sons, Ltd.

  17. Estimation of pneumonitis risk in three-dimensional treatment planning using dose-volume histogram analysis

    International Nuclear Information System (INIS)

    Oetzel, Dieter; Schraube, Peter; Hensley, Frank; Sroka-Perez, Gabriele; Menke, Markus; Flentje, Michael

    1995-01-01

    Purpose: Investigations to study correlations between the estimations of biophysical models in three dimensional (3D) treatment planning and clinical observations are scarce. The development of clinically symptomatic pneumonitis in the radiotherapy of thoracic malignomas was chosen to test the predictive power of Lyman's normal tissue complication probability (NTCP) model for the assessment of side effects for nonuniform irradiation. Methods and Materials: In a retrospective analysis individual computed-tomography-based 3D dose distributions of a random sample of (46(20)) patients with lung/esophageal cancer were reconstructed. All patients received tumor doses between 50 and 60 Gy in a conventional treatment schedule. Biological isoeffective dose-volume histograms (DVHs) were used for the calculation of complication probabilities after applying Lyman's and Kutcher's DVH-reduction algorithm. Lung dose statistics were performed for single lung (involved ipsilateral and contralateral) and for the lung as a paired organ. Results: In the lung cancer group, about 20% of the patients (9 out of 46) developed pneumonitis 3-12 (median 7.5) weeks after completion of radiotherapy. For the majority of these lung cancer patients, the involved ipsilateral lung received a much higher dose than the contralateral lung, and the pneumonitis patients had on average a higher lung exposure with a doubling of the predicted complication risk (38% vs. 20%). The lower lung exposure for the esophagus patients resulted in a mean lung dose of 13.2 Gy (lung cancer: 20.5 Gy) averaged over all patients in correlation with an almost zero complication risk and only one observed case of pneumonitis (1 out of 20). To compare the pneumonitis risk estimations with observed complication rates, the patients were ranked into bins of mean ipsilateral lung dose. Particularly, in the bins with the highest patient numbers, a good correlation was achieved. Agreement was not reached for the lung functioning as

  18. Low-dose total skin electron beam therapy for cutaneous lymphoma. Minimal risk of acute toxicities

    Energy Technology Data Exchange (ETDEWEB)

    Kroeger, Kai; Elsayad, Khaled; Moustakis, Christos; Haverkamp, Uwe; Eich, Hans Theodor [University Hospital of Muenster, Department of Radiation Oncology, Muenster (Germany)

    2017-12-15

    Low-dose total skin electron beam therapy (TSEBT) is attracting increased interest for the effective palliative treatment of primary cutaneous T-cell lymphoma (pCTCL). In this study, we compared toxicity profiles following various radiation doses. We reviewed the records of 60 patients who underwent TSEBT for pCTCL between 2000 and 2016 at the University Hospital of Munster. The treatment characteristics of the radiotherapy (RT) regimens and adverse events (AEs) were then analyzed and compared. In total, 67 courses of TSEBT were administered to 60 patients. Of these patients, 34 (51%) received a standard dose with a median surface dose of 30 Gy and 33 patients (49%) received a low dose with the median surface dose of 12 Gy (7 salvage low-dose TSEBT courses were administered to 5 patients). After a median follow-up of 15 months, the overall AE rate was 100%, including 38 patients (57%) with grade 2 and 7 (10%) with grade 3 AEs. Patients treated with low-dose TSEBT had significantly fewer grade 2 AEs than those with conventional dose regimens (33 vs. 79%, P < 0.001). A lower grade 3 AE rate was also observed in patients who had received the low-dose regimen compared to those with the conventional dose regimens (6 vs. 15%, P = 0.78). Multiple/salvage low-dose TSEBT courses were not associated with an increased risk of acute AEs. Low-dose TSEBT regimens are associated with significantly fewer grade 2 acute toxicities compared with conventional doses of TSEBT. Repeated/Salvage low-dose TSEBT, however, appears to be tolerable and can even be applied safely in patients with cutaneous relapses. (orig.) [German] Eine niedrigdosierte Ganzhautelektronenbestrahlung (TSEBT) wird vermehrt zur effektiven palliativen Behandlung von Patienten mit primaer kutanen T-Zell-Lymphomen (pCTCL) eingesetzt. In dieser Studie vergleichen wir die Toxizitaetsprofile verschiedener Dosiskonzepte. Untersucht wurden 60 zwischen 2000 und 2016 am Universitaetsklinikum Muenster mittels TSEBT

  19. Estimation of organ doses and risk of cancer associated with CT examination

    International Nuclear Information System (INIS)

    Ahmed, Nagla Nooraldaim

    2017-11-01

    The purpose of this study to estimate the organ closes and risk of cancer associated with CT examinations in Khartoum state, where the study conducted in three hospitals; Alzytouna , royal scan and Royal Care. From April to November 2017, and the data collected from 120 patients, 40 patents from each hospital undergoing CT brain and abdomen examinations. The data were entered to CT - Expo version 2.4 software for calculation the effective dose and organ dose and by Xray risk web site for calculate the risk factor associated with CT examinations. Results have shown the values of effective dose that found 9.73 mSv for all patients and for female and male 9.9 mSv respectively. The effective dose from Brain examinations in three hospitals Alzytouna Royal scan and Royal Care was 16.9 mSv, 3.7 mSv, 3.8 mSv respectively, and from abdomen examinations was 4.2 mSv, 7.6 mSv, 22.2 mSv respectively. Comparing te effective dose from the hospitals, for Ct. Brain in Alzytouna hospital was higher than other hospitals; and for CT Abdomen in Royal Care hospital was higher than other hospitals, but still under the risk levels according to the ICRP report. For organ doses results, the most organs exposed from CT. brain was brain, salivary gland, thyroid gland, Bone marrow, Bone surface, Extra thoracic tissue, Eye lens and oral mucosa received ( 70,2, 66.4,15.04, 10.9, 24.9, 14.8,89.5,65.07) mSv respectively. The most organs exposed from CT. Abdomen were liver, stomach, low, Large intestine, Bladder, Bone surface, upper , Large intestine, spleen, kidney, small intestine and prostate received (16.53, 12.8, 33.43, 41.01,20.5, 38.4, 14.7, 28.9, 37.5,30.5 ) mSv respectively. This study found that te ability of cancer induced i the female was higher from the male; dut to body component of the female. (Author)

  20. High-dose anti-histamine use and risk factors in children with urticaria.

    Science.gov (United States)

    Uysal, Pınar; Avcil, Sibelnur; Erge, Duygu

    2016-12-01

    The drugs of choice in the treatment of urticaria in children are H1-antihistamines. The aim of the study was to evaluate children with urticaria and define risk factors for requirement of high-dose H1-antihistamines in children with urticaria. The medical data of children who were diagnosed as having urticaria admitted to our outpatient clinic between January 2014 and January 2016 were searched. The medical histories, concomitant atopic diseases, parental atopy histories, medications, treatment responses, blood eosinophil and basophil counts, and serum total IgE levels were recorded. In addition, the urticaria activity score for seven days, autoimmune antibody tests, and skin prick test results were evaluated in children with chronic urticaria. The numbers of the children with acute and chronic urticaria were 138 and 92, respectively. The age of the children with chronic urticaria was higher than that of those with acute urticaria (p0.05). There was a negative correlation between blood eosinophil count and the UAS7 score in children with chronic urticaria (r=-0.276, p=0.011). Chronic urticaria and requirement of high dose H1-antihistamines were significant in children aged ≥10 years (p<0.001, p=0.015). High UAS7 score (OR: 1.09; CI 95%: [1.03-1.15]) and basopenia (OR: 6.77; CI 95%: [2.01-22.75]) were associated with the requirement of high-dose H1-AH in children with chronic urticaria. The requirement of high-dose H1-antihistamines was higher with children's increasing age. Disease severity and basopenia were risk factors for the requirement of high-dose H1-antihistamines.

  1. Doses and risk estimates to the human conceptus due to internal prenatal exposure to radioactive caesium

    International Nuclear Information System (INIS)

    Kalef-Ezra, J.A.

    1997-01-01

    The 1986 nuclear reactor accident at Chernobyl resulted in widespread internal contamination by radioactive caesium. The aim of the present study was to estimate the doses to embryos/fetus in Greece attributed to maternal 134 Cs and 137 Cs intake and the consequent health risks to their offspring. In pregnant women the concentration of total-body caesium (TBCs) was lower than in age-matched non-pregnant women measured during the same month. A detailed study of intake and retention in the members of one family carried out during the three years that followed the accident indicated that the biological half-time of caesium in the women decreased by a factor of two shortly after conception. Then at partus, there was an increase in the biological half-time, reaching a value similar to that before conception. The total-body potassium concentration was constant over the entire period. Doses to the embryo/fetus due to maternal intake was estimated to be about 150 μGy maximally in those conceived between November 1986 and March 1987. When conception took place later, the prenatal dose followed an exponential reduction with a half-time of about 170 d. These prenatal doses do not exceed the doses from either the natural internal potassium, or from the usual external background sources. The risks attributed to maternal 134 Cs and 137 Cs intake were considerably lower than levels that would justify consideration of termination of a pregnancy. In the absence of these data however, 2500 otherwise wanted pregnancies in Greece were terminated following the Chernobyl accident. (author)

  2. "The Dose Makes the Poison": Informing Consumers About the Scientific Risk Assessment of Food Additives.

    Science.gov (United States)

    Bearth, Angela; Cousin, Marie-Eve; Siegrist, Michael

    2016-01-01

    Intensive risk assessment is required before the approval of food additives. During this process, based on the toxicological principle of "the dose makes the poison,ˮ maximum usage doses are assessed. However, most consumers are not aware of these efforts to ensure the safety of food additives and are therefore sceptical, even though food additives bring certain benefits to consumers. This study investigated the effect of a short video, which explains the scientific risk assessment and regulation of food additives, on consumers' perceptions and acceptance of food additives. The primary goal of this study was to inform consumers and enable them to construct their own risk-benefit assessment and make informed decisions about food additives. The secondary goal was to investigate whether people have different perceptions of food additives of artificial (i.e., aspartame) or natural origin (i.e., steviolglycoside). To attain these research goals, an online experiment was conducted on 185 Swiss consumers. Participants were randomly assigned to either the experimental group, which was shown a video about the scientific risk assessment of food additives, or the control group, which was shown a video about a topic irrelevant to the study. After watching the video, the respondents knew significantly more, expressed more positive thoughts and feelings, had less risk perception, and more acceptance than prior to watching the video. Thus, it appears that informing consumers about complex food safety topics, such as the scientific risk assessment of food additives, is possible, and using a carefully developed information video is a successful strategy for informing consumers. © 2015 Society for Risk Analysis.

  3. Radiation Dose and Subsequent Risk for Stomach Cancer in Long-term Survivors of Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kleinerman, Ruth A., E-mail: kleinerr@mail.nih.gov [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Rockville, Maryland (United States); Smith, Susan A. [Department of Radiation Physics, University of Texas M D Anderson Cancer Center, Houston, Texas (United States); Holowaty, Eric [Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario (Canada); Hall, Per [Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm (Sweden); Pukkala, Eero [Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Helsinki (Finland); Vaalavirta, Leila [Department of Oncology, Helsinki University Central Hospital, Helsinki (Finland); Stovall, Marilyn; Weathers, Rita [Department of Radiation Physics, University of Texas M D Anderson Cancer Center, Houston, Texas (United States); Gilbert, Ethel [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Rockville, Maryland (United States); Aleman, Berthe M.P. [Department of Radiotherapy, The Netherlands Cancer Institute, Amsterdam (Netherlands); Kaijser, Magnus [Clinical Epidemiology Unit, Department of Medicine, Karolinska Institute, Stockholm (Sweden); Andersson, Michael [Department of Oncology, Copenhagen University Hospital, Copenhagen (Denmark); Storm, Hans [Cancer Prevention and Documentation, Danish Cancer Society, Copenhagen (Denmark); Joensuu, Heikki [Department of Oncology, Helsinki University Central Hospital, Helsinki (Finland); Lynch, Charles F. [Department of Epidemiology, University of Iowa, Iowa City, Iowa (United States); and others

    2013-08-01

    Purpose: To assess the dose–response relationship for stomach cancer after radiation therapy for cervical cancer. Methods and Materials: We conducted a nested, matched case–control study of 201 cases and 378 controls among 53,547 5-year survivors of cervical cancer diagnosed from 1943 to 1995, from 5 international, population-based cancer registries. We estimated individual radiation doses to the site of the stomach cancer for all cases and to corresponding sites for the matched controls (overall mean stomach tumor dose, 2.56 Gy, range 0.03-46.1 and after parallel opposed pelvic fields, 1.63 Gy, range 0.12-6.3). Results: More than 90% of women received radiation therapy, mostly with external beam therapy in combination with brachytherapy. Stomach cancer risk was nonsignificantly increased (odds ratio 1.27-2.28) for women receiving between 0.5 and 4.9 Gy to the stomach cancer site and significantly increased at doses ≥5 Gy (odds ratio 4.20, 95% confidence interval 1.41-13.4, P{sub trend}=.047) compared with nonirradiated women. A highly significant radiation dose–response relationship was evident when analyses were restricted to the 131 cases (251 controls) whose stomach cancer was located in the middle and lower portions of the stomach (P{sub trend}=.003), whereas there was no indication of increasing risk with increasing dose for 30 cases (57 controls) whose cancer was located in the upper stomach (P{sub trend}=.23). Conclusions: Our findings show for the first time a significant linear dose–response relationship for risk of stomach cancer in long-term survivors of cervical cancer.

  4. Radiation Dose and Subsequent Risk for Stomach Cancer in Long-term Survivors of Cervical Cancer

    International Nuclear Information System (INIS)

    Kleinerman, Ruth A.; Smith, Susan A.; Holowaty, Eric; Hall, Per; Pukkala, Eero; Vaalavirta, Leila; Stovall, Marilyn; Weathers, Rita; Gilbert, Ethel; Aleman, Berthe M.P.; Kaijser, Magnus; Andersson, Michael; Storm, Hans; Joensuu, Heikki; Lynch, Charles F.

    2013-01-01

    Purpose: To assess the dose–response relationship for stomach cancer after radiation therapy for cervical cancer. Methods and Materials: We conducted a nested, matched case–control study of 201 cases and 378 controls among 53,547 5-year survivors of cervical cancer diagnosed from 1943 to 1995, from 5 international, population-based cancer registries. We estimated individual radiation doses to the site of the stomach cancer for all cases and to corresponding sites for the matched controls (overall mean stomach tumor dose, 2.56 Gy, range 0.03-46.1 and after parallel opposed pelvic fields, 1.63 Gy, range 0.12-6.3). Results: More than 90% of women received radiation therapy, mostly with external beam therapy in combination with brachytherapy. Stomach cancer risk was nonsignificantly increased (odds ratio 1.27-2.28) for women receiving between 0.5 and 4.9 Gy to the stomach cancer site and significantly increased at doses ≥5 Gy (odds ratio 4.20, 95% confidence interval 1.41-13.4, P trend =.047) compared with nonirradiated women. A highly significant radiation dose–response relationship was evident when analyses were restricted to the 131 cases (251 controls) whose stomach cancer was located in the middle and lower portions of the stomach (P trend =.003), whereas there was no indication of increasing risk with increasing dose for 30 cases (57 controls) whose cancer was located in the upper stomach (P trend =.23). Conclusions: Our findings show for the first time a significant linear dose–response relationship for risk of stomach cancer in long-term survivors of cervical cancer

  5. Physicians' knowledge about radiation dose and possible risks of common medical tests: a survey in Iran

    International Nuclear Information System (INIS)

    Zakeri, Farideh; Mianji, Fereidoun; Shakeri, Mahsa; Rajabpour, Mohammad Reza; Farshidpour, Mohammad Reza

    2016-01-01

    Recent data suggest that knowledge of radiation exposures among physicians is inadequate. This study, therefore, aimed to evaluate their knowledge of the radiation doses their patients received and awareness of associated biological risks of radiation exposure. A questionnaire in multiple-choice format consisted of four sections with a total of 10 questions based on the literature review. A total of 136 questionnaires were returned from 69 general practitioners and 67 physicians in various specialties from 10 different hospitals in the capital city of Tehran, Iran. Fifty-four percent of general practitioners and twenty-five percent of specialties declared that they are not aware of biological risks of radiation exposure. Fifty-six percent of physicians did not know the correct definition of absorbed dose. Only 33% of physicians knew the dose exposure of a chest X-ray and only 31% knew the approximate doses of various procedures relative to a chest X-ray. Forty-seven percent of physicians incorrectly distinguished the stochastic effects of radiation from the deterministic effects, and thirty-eight of physicians did not know the organs of the body that are most sensitive to ionizing radiation. Only 23.5% of physicians were aware of the one in 2000 risk of induction of fatal carcinoma from computed tomography of the abdomen. Seventy-nine percent of physicians incorrectly underestimated the contribution of nuclear and radiological tests in exposure of an average person. The mean score of the specialties trended toward being more accurate than general practitioners (4.18 ± 1.28 vs. 3.89 ± 1.46, respectively, from a potential accurate total score of 9), but these differences were not statistically significant. Among specialists, orthopedics had the highest scores. The present study demonstrated the limited knowledge of radiation exposures among general practitioners and specialists and a need to improve their knowledge by means of targeted training and re

  6. Dose conformity of gamma knife radiosurgery and risk factors for complications

    International Nuclear Information System (INIS)

    Nakamura, Jean L.; Verhey, Lynn J.; Smith, Vernon; Petti, Paula L.; Lamborn, Kathleen R.; Larson, David A.; Wara, William M.; McDermott, Michael W.; Sneed, Penny K.

    2001-01-01

    Purpose: To quantitatively evaluate dose conformity achieved using Gamma Knife radiosurgery, compare results with those reported in the literature, and evaluate risk factors for complications. Methods and Materials: All lesions treated at our institution with Gamma Knife radiosurgery from May 1993 (when volume criteria were routinely recorded) through December 1998 were reviewed. Lesions were excluded from analysis for reasons listed below. Conformity index (the ratio of prescription volume to target volume) was calculated for all evaluable lesions and for lesions comparable to those reported in the literature on conformity of linac radiosurgery. Univariate Cox regression models were used to test for associations between treatment parameters and toxicity. Results: Of 1612 targets treated in 874 patients, 274 were excluded, most commonly for unavailability of individual prescription volume data because two or more lesions were included within the same dose matrix (176 lesions), intentional partial coverage for staged treatment of large arteriovenous malformations (AVMs) (33 lesions), and missing target volume data (26 lesions). The median conformity indices were 1.67 for all 1338 evaluable lesions and 1.40-1.43 for lesions comparable to two linac radiosurgery series that reported conformity indices of 1.8 and 2.7, respectively. Among all 651 patients evaluable for complications, there were one Grade 5, eight Grade 4, and 27 Grade 3 complications. Increased risk of toxicity was associated with larger target volume, maximum lesion diameter, prescription volume, or volume of nontarget tissue within the prescription volume. Conclusions: Gamma Knife radiosurgery achieves much more conformal dose distributions than those reported for conventional linac radiosurgery and somewhat more conformal dose distributions than sophisticated linac radiosurgery techniques. Larger target, nontarget, or prescription volumes are associated with increased risk of toxicity

  7. Rat skin carcinogenesis as a basis for estimating risks at low doses and dose rates of various types of radiation

    International Nuclear Information System (INIS)

    Burns, F.J.; Vanderlaan, M.; Strickland, P.; Albert, R.E.

    1976-01-01

    The recovery rate, age dependence and latent period for tumor induction in rat skin were measured for single and split doses of radiation, and the data were analyzed in terms of a general model in an attempt to estimate the expected tumor response for various types of radiation given at low dose rates for long periods of time. The dorsal skin of male rats was exposed to electrons, x rays, or protons in either single or split doses for several doses and the tumor responses were compared during 80 weeks of observation. A two stage model incorporating a reversible or recoverable mode was developed and various parameters in the model, including recovery rate, dose-response coefficients, and indices of age sensitivity, were evaluated experimentally. The measured parameters were then utilized to calculate expected tumor responses for exposure periods extending for duration of life. The calculations indicated that low dose rates could be markedly ( 1 / 100 to 1 / 1000 ) less effective in producing tumors than the same dose given in a short or acute exposure, although the magnitude of the reduction in effectiveness declines as the dose declines

  8. Organ doses, effective doses, and risk indices in adult CT: Comparison of four types of reference phantoms across different examination protocols

    International Nuclear Information System (INIS)

    Zhang Yakun; Li Xiang; Paul Segars, W.; Samei, Ehsan

    2012-01-01

    Purpose: Radiation exposure from computed tomography (CT) to the public has increased the concern among radiation protection professionals. Being able to accurately assess the radiation dose patients receive during CT procedures is a crucial step in the management of CT dose. Currently, various computational anthropomorphic phantoms are used to assess radiation dose by different research groups. It is desirable to better understand how the dose results are affected by different choices of phantoms. In this study, the authors assessed the uncertainties in CT dose and risk estimation associated with different types of computational phantoms for a selected group of representative CT protocols. Methods: Routinely used CT examinations were categorized into ten body and three neurological examination categories. Organ doses, effective doses, risk indices, and conversion coefficients to effective dose and risk index (k and q factors, respectively) were estimated for these examinations for a clinical CT system (LightSpeed VCT, GE Healthcare). Four methods were used, each employing a different type of reference phantoms. The first and second methods employed a Monte Carlo program previously developed and validated in our laboratory. In the first method, the reference male and female extended cardiac-torso (XCAT) phantoms were used, which were initially created from the Visible Human data and later adjusted to match organ masses defined in ICRP publication 89. In the second method, the reference male and female phantoms described in ICRP publication 110 were used, which were initially developed from tomographic data of two patients and later modified to match ICRP 89 organ masses. The third method employed a commercial dosimetry spreadsheet (ImPACT group, London, England) with its own hermaphrodite stylized phantom. In the fourth method, another widely used dosimetry spreadsheet (CT-Expo, Medizinische Hochschule, Hannover, Germany) was employed together with its associated

  9. Organ doses, effective doses, and risk indices in adult CT: Comparison of four types of reference phantoms across different examination protocols

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yakun; Li Xiang; Paul Segars, W.; Samei, Ehsan [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States) and Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University, Durham, North Carolina 27705 (United States) and Departments of Physics, Biomedical Engineering, and Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States)

    2012-06-15

    Purpose: Radiation exposure from computed tomography (CT) to the public has increased the concern among radiation protection professionals. Being able to accurately assess the radiation dose patients receive during CT procedures is a crucial step in the management of CT dose. Currently, various computational anthropomorphic phantoms are used to assess radiation dose by different research groups. It is desirable to better understand how the dose results are affected by different choices of phantoms. In this study, the authors assessed the uncertainties in CT dose and risk estimation associated with different types of computational phantoms for a selected group of representative CT protocols. Methods: Routinely used CT examinations were categorized into ten body and three neurological examination categories. Organ doses, effective doses, risk indices, and conversion coefficients to effective dose and risk index (k and q factors, respectively) were estimated for these examinations for a clinical CT system (LightSpeed VCT, GE Healthcare). Four methods were used, each employing a different type of reference phantoms. The first and second methods employed a Monte Carlo program previously developed and validated in our laboratory. In the first method, the reference male and female extended cardiac-torso (XCAT) phantoms were used, which were initially created from the Visible Human data and later adjusted to match organ masses defined in ICRP publication 89. In the second method, the reference male and female phantoms described in ICRP publication 110 were used, which were initially developed from tomographic data of two patients and later modified to match ICRP 89 organ masses. The third method employed a commercial dosimetry spreadsheet (ImPACT group, London, England) with its own hermaphrodite stylized phantom. In the fourth method, another widely used dosimetry spreadsheet (CT-Expo, Medizinische Hochschule, Hannover, Germany) was employed together with its associated

  10. Dose-stochastic radiobiological effect relationship in model of two reactions and estimation of radiation risk

    International Nuclear Information System (INIS)

    Komochkov, M.M.

    1997-01-01

    The model of dose-stochastic effect relationship for biological systems capable of self-defence under danger factor effect is developed. A defence system is realized in two forms of organism reaction, which determine innate μ n and adaptive μ a radiosensitivities. The significances of μ n are determined by host (inner) factors; and the significances of μ a , by external factors. The possibilities of adaptive reaction are determined by the coefficient of capabilities of the defence system. The formulas of the dose-effect relationship are the solutions of differential equations of assumed process in the defence system of organism. The model and formulas have been checked both at cell and at human levels. Based on the model and personal monitoring data, the estimation of radiation risk at the Joint Institute for Nuclear Research is done

  11. The risk of childhood cancer from low doses of ionizing radiation received in utero

    International Nuclear Information System (INIS)

    Wakeford, R.; Doll, R.; Bithell, J.F.

    1997-01-01

    Radiological protection is based upon the assumption that any additional exposure to ionising radiation leads to an increased risk of stochastic adverse health effects. The validity of this assumption is supported by the epidemiological association between childhood cancer and X-ray exposure of the fetus in utero for diagnostic purposes. Evidence for a direct causal interpretation of this association is compelling: the association has high statistical significance, it is consistent across many case-control studies carried out worldwide, and an appropriate dose-response relationship is indicated. Evidence against bias and confounding as alternative explanations is strong. Nonetheless, objections to causality have been raised. Four grounds for controversy are examined in detail, with the conclusion that they do not provide persuasive evidence against a cause and effect relationship. We conclude that acute doses of the order of 10 mGy received by the fetus in utero cause a subsequent increase in the risk of cancer in childhood, and that, in these circumstances, the excess absolute risk coefficient for childhood cancer incidence is 6-12% per Gy. (author)

  12. Contamination and cancers: low-dose risks and standards of radioprotection

    International Nuclear Information System (INIS)

    Vignes, S.

    1980-01-01

    Irradiation of the population due to the running of nuclear power stations represents less than 1% of the natural radioactivity today, and should amount to 3% at most by the year 2 000. The main effects of ionizing radiations are reviewed and their undetectability below 100 rems is underlined. Thus the evaluation of low-dose risks can only be speculative and the cautions hypothesis adopted is that of a linear relationship between dose and effect, together with the absence of threshold. According to calculations the worker, supposedly exposed to 500 mrem a year between ages 18 and 65, would run a 22.2% instead of the normal 22% risk of dying of cancer. As for the population, the risk would increase by only 1 per 10 000 in the year 2 000. This means that no other mutagenic and carcinogenic agent is as well regulated as radioactive pollution and efforts directed at a better control of harmful chemicals, for instance, are only taking an example from the ruling on radioprotection [fr

  13. Dose-Volume Analysis of Radiation Nephropathy in Children: Preliminary Report of the Risk Consortium

    International Nuclear Information System (INIS)

    Boelling, Tobias; Ernst, Iris; Pape, Hildegard; Martini, Carmen; Ruebe, Christian; Timmermann, Beate; Fischedick, Karin; Kortmann, Rolf-Dieter; Willich, Normann

    2011-01-01

    Purpose: To characterize kidney function in children and adolescents who had undergone radiation treatment that included parts of the kidney. Methods and Materials: Patients receiving radiotherapy during childhood or adolescence were prospectively registered in Germany's Registry for the Evaluation of Side Effects after Radiation in Childhood and Adolescence (RiSK). Detailed information was recorded regarding radiation doses at the organs at risk since 2001 all over Germany. Toxicity evaluation was performed according to standardized Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria. Results: Up to May 2009, 1086 patients from 62 centers were recruited, including 126 patients (median age, 10.2 years) who underwent radiotherapy to parts of the kidneys. Maximal late toxicity (median follow-up 28.5 months in 74 patients) was characterized as Grade 0 (n = 65), 1 (n = 7) or 2 (n = 2). All patients with late effects had received potentially nephrotoxic chemotherapy. A statistically significant difference between patients with and without Grade 1 toxicity, revealing higher exposed kidney volumes in patients with toxicity, was seen for the kidney volume exposed to 20 Gy (V20; p = 0.031) and 30 Gy (V30; p = 0.003). Conclusions: Preliminary data indicate that radiation-induced kidney function impairment is rare in current pediatric multimodal treatment approaches. In the future, RiSK will be able to provide further detailed data regarding dose-volume effect relationships of radiation-associated side effects in pediatric oncology patients.

  14. Information about radiation dose and risks in connection with radiological examinations: what patients would like to know

    International Nuclear Information System (INIS)

    Ukkola, Leila; Oikarinen, Heljae; Haapea, Marianne; Tervonen, Osmo; Henner, Anja; Honkanen, Hilkka

    2016-01-01

    To find out patients' wishes for the content and sources of the information concerning radiological procedures. A questionnaire providing quantitative and qualitative data was prepared. It comprised general information, dose and risks of radiation, and source of information. Two tables demonstrating different options to indicate the dose or risks were also provided. Patients could give one or many votes. Altogether, 147 patients (18-85 years) were interviewed after different radiological examinations using these devices. 95 % (139/147) of the patients wished for dose and risk information. Symbols (78/182 votes) and verbal scale (56/182) were preferred to reveal the dose, while verbal (83/164) and numerical scale (55/164) on the risk of fatal cancer were preferred to indicate the risks. Wishes concerning the course, options and purpose of the examination were also expressed. Prescriber (3.9 on a scale 1-5), information letter (3.8) and radiographer (3.3) were the preferred sources. Patients aged 66-85 years were reluctant to choose electronic channels. Apart from general information, patients wish for dose and risk information in connection with radiological examinations. The majority preferred symbols to indicate dose and verbal scales to indicate risks, and the preferred source of information was the prescriber or information letter. (orig.)

  15. Dose-response relationship analysis for cancer and circulatory system disease mortality risks among uranium miners

    International Nuclear Information System (INIS)

    Drubay, Damien

    2015-01-01

    The relation between lung cancer risk and radon exposure has been clearly established, especially from the studies on uranium miner cohorts. But the association between radon exposure and extrapulmonary cancers and non-cancer diseases remains not well known. Moreover, the health risks associated with the other mining-related ionizing radiation exposures are still under consideration. The aim of this thesis is to contribute to the estimation of the radio-induced health risks at low-doses through the analysis of the kidney cancer and Circulatory System Disease (CSD) mortality risks among uranium miners. Kidney cancer mortality risk analyses were performed from the French cohort of uranium miners (n=5086; follow-up period: 1946-2007), the post-55 cohort (n=3,377; follow-up period: 1957-2007) and the German cohort of the Wismut (n=58,986; follow-up period: 1946-2003) which included 24, 11 and 174 deaths from kidney cancer, respectively. The exposures to radon and its short-lived progeny (expressed in Working Level Month WLM), to uranium ore dust (kBqh.m -3 ) and to external gamma rays (mSv) were estimated for each miners and the equivalent kidney dose was calculated. The dose-response relation was refined considering two responses: the instantaneous risk of kidney cancer mortality (corresponding to the classical analysis, Cause specific Hazard Ratio (CSHR) estimated with the Cox model) and its occurrence probability during the followup (Sub-distribution Hazard Ratio (SHR) estimated with the Fine and Gray model). An excess of kidney cancer mortality was observed only in the French cohort (SMR = 1.62 CI95%[1.04; 2.41]). In the Wismut cohort, a decrease of the kidney cancer mortality was observed (0.89 [0.78; 0.99]). For these three cohorts, the occupational radiological exposures (or the equivalent kidney dose) were significantly associated neither with the risk of kidney cancer mortality (e.g. CSHRWismut-radon/100 WLM=1.023 [0.993; 1.053]), nor with its occurrence

  16. The Increase in Animal Mortality Risk following Exposure to Sparsely Ionizing Radiation Is Not Linear Quadratic with Dose

    OpenAIRE

    Haley, Benjamin M.; Paunesku, Tatjana; Grdina, David J.; Woloschak, Gayle E.

    2015-01-01

    Introduction The US government regulates allowable radiation exposures relying, in large part, on the seventh report from the committee to estimate the Biological Effect of Ionizing Radiation (BEIR VII), which estimated that most contemporary exposures- protracted or low-dose, carry 1.5 fold less risk of carcinogenesis and mortality per Gy than acute exposures of atomic bomb survivors. This correction is known as the dose and dose rate effectiveness factor for the life span study of atomic bo...

  17. The use of the effective dose equivalent, Hsub(E), as a risk parameter in computed tomography

    International Nuclear Information System (INIS)

    Huda, W.; Sandison, G.A.

    1986-01-01

    This note employs the concept of the effective dose equivalent, Hsub(E) to overcome the problems of comparing the non-uniform radiation doses encountered in CT examinations with the whole-body dose-equivalent limits imposed for non-medical exposures for members of the public (5 mSv/year), or with the risks from familiar everyday activities such as smoking cigarettes or driving cars. (U.K.)

  18. Low Dose Radiation Cancer Risks: Epidemiological and Toxicological Models. Final Technical Report

    International Nuclear Information System (INIS)

    Hoel, David G.

    2012-01-01

    The basic purpose of this one year research grant was to extend the two stage clonal expansion model (TSCE) of carcinogenesis to exposures other than the usual single acute exposure. The two-stage clonal expansion model of carcinogenesis incorporates the biological process of carcinogenesis, which involves two mutations and the clonal proliferation of the intermediate cells, in a stochastic, mathematical way. The current TSCE model serves a general purpose of acute exposure models but requires numerical computation of both the survival and hazard functions. The primary objective of this research project was to develop the analytical expressions for the survival function and the hazard function of the occurrence of the first cancer cell for acute, continuous and multiple exposure cases within the framework of the piece-wise constant parameter two-stage clonal expansion model of carcinogenesis. For acute exposure and multiple exposures of acute series, it is either only allowed to have the first mutation rate vary with the dose, or to have all the parameters be dose dependent; for multiple exposures of continuous exposures, all the parameters are allowed to vary with the dose. With these analytical functions, it becomes easy to evaluate the risks of cancer and allows one to deal with the various exposure patterns in cancer risk assessment. A second objective was to apply the TSCE model with varing continuous exposures from the cancer studies of inhaled plutonium in beagle dogs. Using step functions to estimate the retention functions of the pulmonary exposure of plutonium the multiple exposure versions of the TSCE model was to be used to estimate the beagle dog lung cancer risks. The mathematical equations of the multiple exposure versions of the TSCE model were developed. A draft manuscript which is attached provides the results of this mathematical work. The application work using the beagle dog data from plutonium exposure has not been completed due to the fact

  19. Risks of circulatory diseases among Mayak PA workers with radiation doses estimated using the improved Mayak Worker Dosimetry System 2008

    Energy Technology Data Exchange (ETDEWEB)

    Moseeva, Maria B.; Azizova, Tamara V.; Grigoryeva, Evgenia S. [Southern Urals Biophysics Institute (SUBI), Ozyorsk, Chelyabinsk Region (Russian Federation); Haylock, Richard [Public Health of England, London (United Kingdom)

    2014-05-15

    The new Mayak Worker Dosimetry System 2008 (MWDS-2008) was published in 2013 and supersedes the Doses-2005 dosimetry system for Mayak Production Association (PA) workers. It provides revised external and internal dose estimates based on the updated occupational history data. Using MWDS-2008, a cohort of 18,856 workers first employed at one of the main Mayak PA plants during 1948-1972 and followed up to 2005 was identified. Incidence and mortality risks from ischemic heart disease (IHD) (International Classification of Diseases (ICD)-9 codes 410-414) and from cerebrovascular diseases (CVD) (ICD-9 codes 430-438) were examined in this cohort and compared with previously published risk estimates in the same cohort based on the Doses-2005 dosimetry system. Significant associations were observed between doses from external gamma-rays and IHD and CVD incidence and also between internal doses from alpha-radiation and IHD mortality and CVD incidence. The estimates of excess relative risk (ERR)/Gy were consistent with those estimates from the previous studies based on Doses-2005 system apart from the relationship between CVD incidence and internal liver dose where the ERR/Gy based on MWDS-2008 was just over three times higher than the corresponding estimate based on Doses-2005 system. Adjustment for smoking status did not show any effect on the estimates of risk from internal alpha-particle exposure. (orig.)

  20. U.S.Department of energy low dose radiation research program: potential impact on Human health risk from Chornobyl

    International Nuclear Information System (INIS)

    Brooks, A.

    2002-01-01

    Radiation risks from low levels of radiation exposure, cannot be predicted with epidemiological studies alone. Combining advances in technology with those in cell and molecular biology make it possible to detect biological changes after low doses and dose-rates of radiation exposure, such as Chornobyl. Understanding the role of these biological changes in cancer risk may or may not impact radiation protection standards. However, they will help ensure that the standards are both adequate and appropriate

  1. Youth suicide attempts and the dose-response relationship to parental risk factors: a population-based study

    DEFF Research Database (Denmark)

    Christiansen, E; Goldney, R D; Beautrai, A L

    2011-01-01

    BACKGROUND: There is a lack of specific knowledge about the dose-response effect of multiple parental risk factors for suicide attempts among children and adolescents. The aim of this study was to determine the dose-response effect of multiple parental risk factors on an offspring's risk for suic......BACKGROUND: There is a lack of specific knowledge about the dose-response effect of multiple parental risk factors for suicide attempts among children and adolescents. The aim of this study was to determine the dose-response effect of multiple parental risk factors on an offspring's risk...... for suicide attempt.MethodWe designed a population-based two-generation nested case-control study and used Danish register data. A population of 403 431 individuals born between 1983 and 1989 was sampled. Among these, 3465 (0.8%) were registered as having had a suicide attempt. Twenty controls were matched...... to each case and a link to the offspring's biological parents was established. RESULTS: There was a dose-response relationship between the number of exposures and the risk of suicide attempts, with the increased risk seeming to be a multiplicative effect. Parental suicide, suicide attempt, psychiatric...

  2. Risk and benefit associated with radiation dose in breast screening programmes - an update

    International Nuclear Information System (INIS)

    Law, J.

    1995-01-01

    This paper discusses and attempts to estimate the very small numbers of women attending the UK Breast Screening Programme for whom the risk of cancer induction may exceed the probability of cancer detection. It updates a previous paper on the same topic. Variations in breast dose between individuals, due to differences in breast size and in numbers of views and films taken, are considered and revised. New data on cancer induction and its variation with age at exposure have been employed. The overall effect of these changes is generally to improve the balance of benefit against risk compared with the previous paper referred to, the very few exceptions being categories where the numbers of women in question remain of the order of one in a million. The implications for certain alternative screening schedules and for some current trials are also discussed, the conclusions being again reasonably reassuring. (author)

  3. Low dose irradiation and risk of leukaemia: A case-control study

    International Nuclear Information System (INIS)

    Chobanova, N.; Bayrakova, A.

    1997-01-01

    The effect of low dose irradiation (medical X-ray diagnostic) on the developing of leukaemias in adults is investigated. The influence of non-radiation agents (occupational exposure to chemical carcinogens, past viral infections, family aggregations) to leukaemias are considered also. During this retrospective study 228 patients have been examined with the following diagnosis: acute myeloid leukaemia, chronic myelogenous leukaemias, myelodisplastic syndrome and non-Hodgkin lymphoma (diagnosed between 1991-1993). Each case has been matched with two controls. Statistically significant increase has been found in the risk of developing leukaemias after X-ray diagnostic irradiation (OR = 1.98, 95% CI = 1.14 ./. 3.46). Exposure to chemical agents is also associated with significant increase in the risk (OR = 1.98, 95% CI = 1.25 ./. 2.86). (author)

  4. Evaluation of Low- Versus High-dose Valganciclovir for Prevention of Cytomegalovirus Disease in High-risk Renal Transplant Recipients.

    Science.gov (United States)

    Gabardi, Steven; Asipenko, Natalya; Fleming, James; Lor, Kevin; McDevitt-Potter, Lisa; Mohammed, Anisa; Rogers, Christin; Tichy, Eric M; Weng, Renee; Lee, Ruth-Ann

    2015-07-01

    Despite proven efficacy of prolonged cytomegalovirus (CMV) prophylaxis using valganciclovir 900 mg/day, some centers use 450 mg/day due to reported success and cost savings. This multicenter, retrospective study compared the efficacy and safety of 6 months of low-dose versus high-dose valganciclovir prophylaxis in high-risk, donor-positive/recipient-negative, renal transplant recipients (RTR). Two hundred thirty-seven high-risk RTR (low-dose group = valganciclovir 450 mg/day [n = 130]; high-dose group = valganciclovir 900 mg/day [n = s7]) were evaluated for 1-year CMV disease prevalence. Breakthrough CMV, resistant CMV, biopsy-proven acute rejection (BPAR), graft loss, opportunistic infections (OI), new-onset diabetes after transplantation (NODAT), premature valganciclovir discontinuation, renal function and myelosuppression were also assessed. Patient demographics and transplant characteristics were comparable. Induction and maintenance immunosuppression were similar, except for more early steroid withdrawal in the high-dose group. Similar proportions of patients developed CMV disease (14.6% vs 24.3%; P = 0.068); however, controlling CMV risk factor differences through multivariate logistic regression revealed significantly lower CMV disease in the low-dose group (P = 0.02; odds ratio, 0.432, 95% confidence interval, 0.211-0.887). Breakthrough and resistant CMV occurred at similar frequencies. There was no difference in renal function or rates of biopsy-proven acute rejection, graft loss, opportunistic infections, or new-onset diabetes after transplantation. The high-dose group had significantly lower mean white blood cell counts at months 5 and 6; however, premature valganciclovir discontinuation rates were similar. Low-dose and high-dose valganciclovir regimens provide similar efficacy in preventing CMV disease in high-risk RTR, with a reduced incidence of leukopenia associated with the low-dose regimen and no difference in resistant CMV. Low-dose valganciclovir

  5. Study of dose and relative risk of occupationally exposed individuals in interventional procedures; Estudo de dose e risco relativo de individuos ocupacionalmente expostos em procedimentos intervencionistas

    Energy Technology Data Exchange (ETDEWEB)

    Silveira Filho, Jose A.M.; Reis, Charlene O.; Taniguti, Lana T.; Pacifico, Leonardo C.; SaintYves, Thalis L.A.; Mecca, Fernando A., E-mail: ze_augustomsf@hotmail.com [Instituto Nacional do Cancer (INCA), Rio de Janeiro, RJ (Brazil). Setor de Fisica Medica

    2012-12-15

    This paper estimates the occupational effective dose and the relative risk of leukemia and cancers of the digestive tract mortality through dose study of the most radiosensitive anatomical regions (lens, thyroid, chest and gonads) of the professionals involved in interventional gonad procedures. It was considered a cumulative exposure time of 10,000 hours, which is the occupational exposure time of an IOE in throughout his professional life. It was also considered that they always use Personal Protective Equipment (PPE). Mathematical models derived from epidemiological data contained in the BEIR V and in the IAEA’s TECDOC 870 are used to estimate the relative risk. The results show a significant increase in mortality risk for these types of cancer for individuals occupationally exposed to three different distances from the x-ray beam, and reinforces that radiation protection measures are essential. (author)

  6. Organ dose and risk assessment in paediatric radiography using the PCXMC 2.0

    Science.gov (United States)

    Ladia, A.; Messaris, G.; Delis, H.; Panayiotakis, G.

    2015-09-01

    Abdominal and chest radiographs are the most common examinations in paediatric radiology. X-ray examination of children attracts particular interest, mainly due to the increased risk for the expression of delayed radiogenic cancers as they have many years of expected life remaining. This study aims to calculate the organ dose and estimate the radiation Risk of Exposure Induced cancer Death (REID) to paediatric patients, using the PCXMC 2.0 Monte Carlo code.Patient data and exposure parameters were recorded during examinations of 240 patients, separated in four age groups undergoing chest or abdomen examinations.The organs received the highest dose in all patient groups were liver, lungs, stomach, thyroid, pancreas, breast, spleen in chest radiographs and liver, lungs, colon, stomach and ovaries, uterus (for girls) and prostate (for boys) in abdomen radiographs. The effective dosefor the chest was 0.49×10-2- 1.07×10-2 mSv, while for the abdomen 1.85×10-2- 3.02×10-2 mSv. The mean REID value was 1.254×10-5 for the abdomen and 0.645×10-5 for the chest.

  7. Dose and risk assessment of norm Contaminated waste released from trench disposal facility

    International Nuclear Information System (INIS)

    Abdel Geleel, M.; Ramadan, A.B.; Tawfik, A.A.

    2005-01-01

    Oil and gas extraction and processing operations accumulate naturally occurring radioactive material (NORM) at concentrations above normal in by-product waste streams. The petroleum industry adopted methods for managing of NORM that are more restrictive than past practices and are likely to provide greater isolation of the radioactivity. Trench was used as a disposal facility for NORM contaminated wastes at one site of the petroleum industry in Egypt. The aim of this work is to calculate the risk and dose assessment received from trench disposal facility directly and after closure (1000 year). RESRAD computer code was used. The results indicated that the total effective dose (TED) received after direct closure of trench disposal facility was 7.7E-4 mSv/y while after 1000 years, it will he 3.4E-4. The health cancer risk after direct closure was 3.3E-8 while after 1000 years post closure it was 6E-8. Results of this assessment will help examine policy issues concerning different options and regulation of NORM contaminated waste generated by petroleum industry

  8. Optimal use of β-blockers in high-risk hypertension: A guide to dosing equivalence

    Directory of Open Access Journals (Sweden)

    Janet B McGill

    2010-05-01

    Full Text Available Janet B McGillDepartment of Medicine, Washington University School of Medicine, St. Louis, Missouri, USAAbstract: Hypertension is the number one diagnosis made by primary care physicians, placing them in a unique position to prescribe the antihypertensive agent best suited to the individual patient. In individuals with diabetes mellitus, blood pressure (BP levels > 130/80 mmHg confer an even higher risk for cardiovascular and renal disease, and these patients will benefit from aggressive antihypertensive treatment using a combination of agents. β‑blockers are playing an increasingly important role in the management of hypertension in high-risk patients. β‑blockers are a heterogeneous class of agents, and this review presents the differences between β‑blockers and provides evidence-based protocols to assist in understanding dose equivalence in the selection of an optimal regimen in patients with complex needs. The clinical benefits provided by β‑blockers are only effective if patients adhere to medication treatment long term. β‑blockers with proven efficacy, once-daily dosing, and lower side effect profiles may become instrumental in the treatment of hypertensive diabetic and nondiabetic patients.Keywords: antihypertensive, blood pressure, atenolol, carvedilol, labetalol, metoprolol, nebivolol

  9. Organ dose and risk assessment in paediatric radiography using the PCXMC 2.0

    International Nuclear Information System (INIS)

    Ladia, A; Messaris, G; Delis, H; Panayiotakis, G

    2015-01-01

    Abdominal and chest radiographs are the most common examinations in paediatric radiology. X-ray examination of children attracts particular interest, mainly due to the increased risk for the expression of delayed radiogenic cancers as they have many years of expected life remaining. This study aims to calculate the organ dose and estimate the radiation Risk of Exposure Induced cancer Death (REID) to paediatric patients, using the PCXMC 2.0 Monte Carlo code.Patient data and exposure parameters were recorded during examinations of 240 patients, separated in four age groups undergoing chest or abdomen examinations.The organs received the highest dose in all patient groups were liver, lungs, stomach, thyroid, pancreas, breast, spleen in chest radiographs and liver, lungs, colon, stomach and ovaries, uterus (for girls) and prostate (for boys) in abdomen radiographs. The effective dosefor the chest was 0.49×10 -2 - 1.07×10 -2 mSv, while for the abdomen 1.85×10 -2 - 3.02×10 -2 mSv. The mean REID value was 1.254×10 -5 for the abdomen and 0.645×10 -5 for the chest. (paper)

  10. Can we avoid high levels of dose escalation for high-risk prostate cancer in the setting of androgen deprivation?

    Science.gov (United States)

    Shakespeare, Thomas P; Wilcox, Shea W; Aherne, Noel J

    2016-01-01

    Both dose-escalated external beam radiotherapy (DE-EBRT) and androgen deprivation therapy (ADT) improve outcomes in patients with high-risk prostate cancer. However, there is little evidence specifically evaluating DE-EBRT for patients with high-risk prostate cancer receiving ADT, particularly for EBRT doses >74 Gy. We aimed to determine whether DE-EBRT >74 Gy improves outcomes for patients with high-risk prostate cancer receiving long-term ADT. Patients with high-risk prostate cancer were treated on an institutional protocol prescribing 3-6 months neoadjuvant ADT and DE-EBRT, followed by 2 years of adjuvant ADT. Between 2006 and 2012, EBRT doses were escalated from 74 Gy to 76 Gy and then to 78 Gy. We interrogated our electronic medical record to identify these patients and analyzed our results by comparing dose levels. In all, 479 patients were treated with a 68-month median follow-up. The 5-year biochemical disease-free survivals for the 74 Gy, 76 Gy, and 78 Gy groups were 87.8%, 86.9%, and 91.6%, respectively. The metastasis-free survivals were 95.5%, 94.5%, and 93.9%, respectively, and the prostate cancer-specific survivals were 100%, 94.4%, and 98.1%, respectively. Dose escalation had no impact on any outcome in either univariate or multivariate analysis. There was no benefit of DE-EBRT >74 Gy in our cohort of high-risk prostate patients treated with long-term ADT. As dose escalation has higher risks of radiotherapy-induced toxicity, it may be feasible to omit dose escalation beyond 74 Gy in this group of patients. Randomized studies evaluating dose escalation for high-risk patients receiving ADT should be considered.

  11. Dose and induction to cancer risk evaluation associated to use of X ray body scanners by transmission at airports

    International Nuclear Information System (INIS)

    Correa, Samanda Cristine Arruda; Aquino, Josilto Oliveira de; Souza, Edmilson Monteiro de; Silva, Ademir Xavier da

    2011-01-01

    This paper uses the Monte Carlo MCNPX and the phantoms in male voxel and female voxel to evaluate the absorbed doses effective doses and the induction risk and the mortality due to cancer associated to exposures of individual submitted to X ray body scanners by transmission at various projections. The values of effective dose were calculated according to the recommended by the new ICRP 103 and the values of induction risks and mortality due to cancer were estimated through the document BEIR VII. (author)

  12. The European initiative on low-dose risk research: from the HLEG to MELODI

    International Nuclear Information System (INIS)

    Belli, Mauro; Tabocchini, Maria Antonella; Jourdain, Jean-Rene; Repussard, Jacques; Salomaa, Sisko

    2015-01-01

    The importance of low-dose risk research for radiation protection is now widely recognised. The European Commission (EC) and five European Union (EU) Member States involved in the Euratom Programme set up in 2008 a 'High Level and Expert Group on European Low Dose Risk Research' (HLEG) aimed at identifying research needs and proposing a better integration of European efforts in the field. The HLEG revised the research challenges and proposed a European research strategy based on a 'Multidisciplinary European Low Dose Initiative' (MELODI). In April 2009, five national organisations, with the support of the EC, created the initial core of MELODI (http://www.melodi-online.eu) with a view to integrate the EU institutions with significant programmes in the field, while being open to other scientific organisations and stakeholders, and to develop an agreed strategic research agenda (SRA) and roadmap. Since then, open workshops have been organised yearly, exploring ideas for SRA implementation. As of October 2014, 31 institutions have been included as members of MELODI. HLEG recommendations and MELODI SRA have become important reference points in the radiation protection part of the Euratom Research Programme. MELODI has established close interactions through Memorandum of Understanding with other European platforms involved in radiation protection (Alliance, NERIS and EURADOS) and, together with EURADOS, with the relevant medical European Associations. The role of Joint Programming in priority setting, foreseen in the forthcoming EU Horizon 2020, calls for keeping MELODI an open, inclusive and transparent initiative, able to avoid redundancies and possible conflicts of interest, while promoting common initiatives in radiation protection research. An important issue is the establishment of a proper methodology for managing these initiatives, and this includes the set-up of an independent MELODI Scientific Committee recently extended to Alliance, NERIS

  13. The European initiative on low-dose risk research: from the HLEG to MELODI.

    Science.gov (United States)

    Belli, Mauro; Tabocchini, Maria Antonella; Jourdain, Jean-René; Salomaa, Sisko; Repussard, Jacques

    2015-09-01

    The importance of low-dose risk research for radiation protection is now widely recognised. The European Commission (EC) and five European Union (EU) Member States involved in the Euratom Programme set up in 2008 a 'High Level and Expert Group on European Low Dose Risk Research' (HLEG) aimed at identifying research needs and proposing a better integration of European efforts in the field. The HLEG revised the research challenges and proposed a European research strategy based on a 'Multidisciplinary European LOw Dose Initiative' (MELODI). In April 2009, five national organisations, with the support of the EC, created the initial core of MELODI (http://www.melodi-online.eu) with a view to integrate the EU institutions with significant programmes in the field, while being open to other scientific organisations and stakeholders, and to develop an agreed strategic research agenda (SRA) and roadmap. Since then, open workshops have been organised yearly, exploring ideas for SRA implementation. As of October 2014, 31 institutions have been included as members of MELODI. HLEG recommendations and MELODI SRA have become important reference points in the radiation protection part of the Euratom Research Programme. MELODI has established close interactions through Memorandum of Understanding with other European platforms involved in radiation protection (Alliance, NERIS and EURADOS) and, together with EURADOS, with the relevant medical European Associations. The role of Joint Programming in priority setting, foreseen in the forthcoming EU Horizon 2020, calls for keeping MELODI an open, inclusive and transparent initiative, able to avoid redundancies and possible conflicts of interest, while promoting common initiatives in radiation protection research. An important issue is the establishment of a proper methodology for managing these initiatives, and this includes the set-up of an independent MELODI Scientific Committee recently extended to Alliance, NERIS and EURADOS, with

  14. Applicability of the tissue stem cell turnover concept on the validity of cumulative dose based radiation risk evaluation

    International Nuclear Information System (INIS)

    Otsuka, Kensuke; Hamada, Nobuyuki; Iwasaki, Toshiyasu; Yoshida, Kazuo

    2011-01-01

    The radiation protection system adopts the linear no-threshold model to achieve proper radiation protection for considering cancer risks resulting from radiation exposure. This model uses cumulative dose to a tissue for risk evaluation in which cumulative dose is related to the amount of DNA damage and consequential induction of gene mutation. In this concept, gene mutation accumulates in tissue stem cells, the putative target of carcinogenesis, with total dose given to the tissue. Unlike high-dose-rate exposure, epidemiological studies in high radiation background areas, such as Kerala in India, revealed that cancer risks is not elevated by the dose to the inhabitants, suggesting that there exists some mechanisms to eliminate the damage/mutation in the exposed tissue under extremely low-dose-rate exposure situations. In this report, the dynamics of tissue stem cell turnover is evaluated as a possible mechanism under extremely low-dose-rate exposure situations. To this end, we reviewed recent literatures studying tissue stem cell turnover, and found that great advances in stem cell research have made it possible to trace a fate of stem cells in tissues. Furthermore, turnover of tissue stem cells is found to occur after irradiation, due to competition of stem cells within tissues. This raises a possibility that radiation effects may not accumulate in a tissue depending on the dose-rate and duration of exposure period. (author)

  15. The carcinogenic risk of high dose total body irradiation in non-human primates

    International Nuclear Information System (INIS)

    Broerse, J.J.; Bartstra, R.W.; Bekkum, D.W. van; Hage, M.H. van der; Zurcher, C.; Zwieten, M.J. van; Hollander, C.F.

    2000-01-01

    High dose total body irradiation (TBI) in combination with chemotherapy, followed by rescue with bone marrow transplantation (BMT), is increasingly used for the treatment of haematological malignancies. With the increasing success of this treatment and its current introduction for treating refractory autoimmune diseases the risk of radiation carcinogenesis is of growing concern. Studies on turnout induction in non-human primates are of relevance in this context since the response of this species to radiation does not differ much from that in man. Since the early sixties, studies have been performed on acute effects in Rhesus monkeys and the protective action of bone marrow transplantation after irradiation with X-rays (average total body dose 6.8 Gy) and fission neutrons (average dose 3.4 Gy). Of those monkeys, which were irradiated and reconstituted with autologous bone marrow, 20 animals in the X-irradiated group and nine animals in the neutron group survived more than 3 years. A group of 21 non-irradiated Rhesus monkeys of a comparable age distribution served as controls. All animals were regularly screened for the occurrence of neoplasms. Complete necropsies were performed after natural death or euthanasia. At post-irradiation intervals of 4-21 years an appreciable number of tumours was observed. In the neutron irradiated group eight out of nine animals died with one or more malignant tumours. In the X-irradiated group this fraction was 10 out of 20. The tumours in the control group, in seven out of the 21 animals, appeared at much older a-e compared with those in the irradiated cohorts. The histogenesis of the tumours was diverse with a preponderance of renal carcinoma, sarcomas among which osteosarcormas, and malignant glomus tumours in the irradiated groups. When corrected for competing risks, the carcinogenic risk of TBI in the Rhesus monkeys is similar to that derived from the studies of the Japanese atomic bomb survivors. The increase of the risk by a

  16. Evaluation of organ dose and estimation of risk due to the abdominal region radiography in Indian adults

    International Nuclear Information System (INIS)

    Kumaresan, M.; Chaubey, Ajay; Kantharia, Surita; Karira, V.; Kumar, Rajesh; Biju, K.; Rao, B.S.

    2006-01-01

    Organ dose, risk of carcinogenesis and genetic effect due to the abdominal region radiography in Indian adult with the help of Monte-Carlo MCNP code by measuring the entrance skin dose by LiF: Mg, Cu, P TL phosphor and the risk coefficients provided by ICRP 60 were estimated. The entrance skin dose for abdominal region radiography was ranges from 2.75 mSv to 18.88 mSv while average entrance skin dose was 8.3 mSv. The bladder, testes and ovary are the important organ those are getting higher dose. The maximum dose for testes, ovary and bladder is 5.37 mSv, 1.45 mSv and 4.74 mSv respectively. The frequency of occurrence of fatal cancers and serious genetic disorders as a consequence of abdominal region radiography ranges from 0.1 to 38.8 risk/10 6 of fatal cancer. Although the estimated risks are small but cannot be neglected. It is important to avoid unnecessary repetitions and also to carry out proper quality assurance tests on the equipment and in the long run it will help reduce the risks and maximize the benefits of radiodiagnosis. These studies may lead to setting up of national reference levels for the diagnostic procedures India. (author)

  17. TU-C-18A-01: Models of Risk From Low-Dose Radiation Exposures: What Does the Evidence Say?

    International Nuclear Information System (INIS)

    Bushberg, J; Boreham, D; Ulsh, B

    2014-01-01

    At dose levels of (approximately) 500 mSv or more, increased cancer incidence and mortality have been clearly demonstrated. However, at the low doses of radiation used in medical imaging, the relationship between dose and cancer risk is not well established. As such, assumptions about the shape of the dose-response curve are made. These assumptions, or risk models, are used to estimate potential long term effects. Common models include 1) the linear non-threshold (LNT) model, 2) threshold models with either a linear or curvilinear dose response above the threshold, and 3) a hormetic model, where the risk is initially decreased below background levels before increasing. The choice of model used when making radiation risk or protection calculations and decisions can have significant implications on public policy and health care decisions. However, the ongoing debate about which risk model best describes the dose-response relationship at low doses of radiation makes informed decision making difficult. This symposium will review the two fundamental approaches to determining the risk associated with low doses of ionizing radiation, namely radiation epidemiology and radiation biology. The strengths and limitations of each approach will be reviewed, the results of recent studies presented, and the appropriateness of different risk models for various real world scenarios discussed. Examples of well-designed and poorly-designed studies will be provided to assist medical physicists in 1) critically evaluating publications in the field and 2) communicating accurate information to medical professionals, patients, and members of the general public. Equipped with the best information that radiation epidemiology and radiation biology can currently provide, and an understanding of the limitations of such information, individuals and organizations will be able to make more informed decisions regarding questions such as 1) how much shielding to install at medical facilities, 2) at

  18. TU-C-18A-01: Models of Risk From Low-Dose Radiation Exposures: What Does the Evidence Say?

    Energy Technology Data Exchange (ETDEWEB)

    Bushberg, J [UC Davis Medical Center, Sacramento, CA (United States); Boreham, D [McMaster University, Ontario, CA (Canada); Ulsh, B

    2014-06-15

    At dose levels of (approximately) 500 mSv or more, increased cancer incidence and mortality have been clearly demonstrated. However, at the low doses of radiation used in medical imaging, the relationship between dose and cancer risk is not well established. As such, assumptions about the shape of the dose-response curve are made. These assumptions, or risk models, are used to estimate potential long term effects. Common models include 1) the linear non-threshold (LNT) model, 2) threshold models with either a linear or curvilinear dose response above the threshold, and 3) a hormetic model, where the risk is initially decreased below background levels before increasing. The choice of model used when making radiation risk or protection calculations and decisions can have significant implications on public policy and health care decisions. However, the ongoing debate about which risk model best describes the dose-response relationship at low doses of radiation makes informed decision making difficult. This symposium will review the two fundamental approaches to determining the risk associated with low doses of ionizing radiation, namely radiation epidemiology and radiation biology. The strengths and limitations of each approach will be reviewed, the results of recent studies presented, and the appropriateness of different risk models for various real world scenarios discussed. Examples of well-designed and poorly-designed studies will be provided to assist medical physicists in 1) critically evaluating publications in the field and 2) communicating accurate information to medical professionals, patients, and members of the general public. Equipped with the best information that radiation epidemiology and radiation biology can currently provide, and an understanding of the limitations of such information, individuals and organizations will be able to make more informed decisions regarding questions such as 1) how much shielding to install at medical facilities, 2) at

  19. Radiation Risk Associated with Low Doses of Ionizing Radiation: Irrational Fear or Real Danger

    International Nuclear Information System (INIS)

    Reshetin, V.

    2007-01-01

    The established worldwide practice of protecting people from radiation based on the assessments of radiation risk received in the researches carried out earlier costs hundreds of billions of dollars a year to implement. In the opinion of the well-known experts, the maintenance of the existing radiation protection regulations or moreover acceptance of more tough regulations can influence the development of nuclear power engineering. The accepted practice of assessment of human health risk from radiation may also significantly affect our perception of threats of radiation terrorism. In this work, the critical analysis of publications on the assessment of the effects of small doses of radiation on human health is carried out. In our analysis, we especially emphasize the data on cancer mortality among survivors of the atomic bombing of Hiroshima and Nagasaki who received instantaneous radiation doses of less than 200 mSv including the data on leukemia and solid cancer, as well as epidemiological studies in the regions of India and China with high level of natural radiation. Since the investigations of radiation risk is a base for formulating modern radiation protection regulations, their reliability and validity are of great importance. As follows from the analysis, the subsequent, during three decades, toughening of radiation protection regulations has already led to exceedingly prohibitive standards and impractical recommendations the science-based validity of which can cause serious doubts. Now, a number of world-wide known scientists and authoritative international organizations call for revision of these standards and of the radiation safety concept itself. (author)

  20. SU-E-I-54: Effective Dose and Radiation Cancer Risks for Scoliosis Patients Undergoing Full Spine Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259, Wen-Hwa 1st Road., Kwei-Shan, Taoyuan 333, Taiwan (China); Hwang, Y [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan (China); Tsai, H [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259, Wen-Hwa 1st Road., Kwei-Shan, Taoyuan 333, Taiwan (China); Medical Physics Research Center, Institute for Radiological Research, Chang Gung University / Chang Gung Memorial Hospital, Linkou, Taoyuan 33302, Taiwan (China); Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan (China)

    2015-06-15

    Purpose: Scoliotic patients underwent a lot of radiologic examinations during the control and treatment periods. This study used the PCXMC program to calculate the effective dose of the patients and assess the radiation cancer risks. Methods: Seventy five scoliotic patients were examined using CR or DR systems during the control and treatment periods in Chang Gung Memorial Hospital. The technical factors were recorded for each patient during his/her control and treatment period. The entrance surface dose was measured using thermoluminence dosimeters and derived from technical factors and irradiated geometry. The effective dose of patients and relative radiation cancer risks were calculated by the PCXMC program. All required information regarding patient age and sex, the x-ray spectra, and the tube voltage and current were registered. The radiation risk were estimated using the model developed by the BEIR VII committee (2006). Results: The effective doses of full spine radiography with anteroposterior and lateral projections were 0.626 mSv for patients using DR systems, and 0.483mSv for patients using CR systems, respectively. The dose using DR system was 29.6% higher than those using CR system. The maximum organ dose was observed in the breast for both projections in all the systems. The risk of exposure—induced cancer death (REID) of patients for DR and CR systems were 0.009% and 0.007%, respectively. Conclusion: The risk estimates were regarded with healthy skepticism, placed more emphasis on the magnitude of the risk. The effective doses estimated in this study could be served as a reference for radiologists and technologists and demonstrate the necessity to optimize patient protection for full spine radiography though the effective doses are not at the level to induce deterministic effects and not significant in the stochastic effect. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1D0421)

  1. Critical dose and toxicity index of organs at risk in radiotherapy: Analyzing the calculated effects of modified dose fractionation in non–small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pedicini, Piernicola, E-mail: ppiern@libero.it [Service of Medical Physics, I.R.C.C.S. Regional Cancer Hospital C.R.O.B, Rionero in Vulture (Italy); Strigari, Lidia [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome (Italy); Benassi, Marcello [Service of Medical Physics, Scientific Institute of Tumours of Romagna I.R.S.T., Meldola (Italy); Caivano, Rocchina [Service of Medical Physics, I.R.C.C.S. Regional Cancer Hospital C.R.O.B, Rionero in Vulture (Italy); Fiorentino, Alba [U.O. of Radiotherapy, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy); Nappi, Antonio [U.O. of Nuclear Medicine, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy); Salvatore, Marco [U.O. of Nuclear Medicine, I.R.C.C.S. SDN Foundation, Naples (Italy); Storto, Giovanni [U.O. of Nuclear Medicine, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy)

    2014-04-01

    To increase the efficacy of radiotherapy for non–small cell lung cancer (NSCLC), many schemes of dose fractionation were assessed by a new “toxicity index” (I), which allows one to choose the fractionation schedules that produce less toxic treatments. Thirty-two patients affected by non resectable NSCLC were treated by standard 3-dimensional conformal radiotherapy (3DCRT) with a strategy of limited treated volume. Computed tomography datasets were employed to re plan by simultaneous integrated boost intensity-modulated radiotherapy (IMRT). The dose distributions from plans were used to test various schemes of dose fractionation, in 3DCRT as well as in IMRT, by transforming the dose-volume histogram (DVH) into a biological equivalent DVH (BDVH) and by varying the overall treatment time. The BDVHs were obtained through the toxicity index, which was defined for each of the organs at risk (OAR) by a linear quadratic model keeping an equivalent radiobiological effect on the target volume. The less toxic fractionation consisted in a severe/moderate hyper fractionation for the volume including the primary tumor and lymph nodes, followed by a hypofractionation for the reduced volume of the primary tumor. The 3DCRT and IMRT resulted, respectively, in 4.7% and 4.3% of dose sparing for the spinal cord, without significant changes for the combined-lungs toxicity (p < 0.001). Schedules with reduced overall treatment time (accelerated fractionations) led to a 12.5% dose sparing for the spinal cord (7.5% in IMRT), 8.3% dose sparing for V{sub 20} in the combined lungs (5.5% in IMRT), and also significant dose sparing for all the other OARs (p < 0.001). The toxicity index allows to choose fractionation schedules with reduced toxicity for all the OARs and equivalent radiobiological effect for the tumor in 3DCRT, as well as in IMRT, treatments of NSCLC.

  2. Dose-dependent risk of malformations with antiepileptic drugs: an analysis of data from the EURAP epilepsy and pregnancy registry

    DEFF Research Database (Denmark)

    Tomson, Torbjörn; Battino, Dina; Bonizzoni, Erminio

    2011-01-01

    Prenatal exposure to antiepileptic drugs is associated with a greater risk of major congenital malformations, but there is inadequate information on the comparative teratogenicity of individual antiepileptic drugs and the association with dose. We aimed to establish the risks of major congenital ...

  3. Parity and pancreatic cancer risk: a dose-response meta-analysis of epidemiologic studies.

    Directory of Open Access Journals (Sweden)

    Hong-Bo Guan

    Full Text Available BACKGROUND: Previous epidemiologic studies have reported inconsistent results between parity and pancreatic cancer (PC risk. To our knowledge, a comprehensive and quantitative assessment of this association has not been conducted. METHODS: Relevant published studies of parity and PC were identified using MEDLINE (PubMed and Web of Science databases until November 2013. Two authors (H-BG and LW independently assessed eligibility and extracted data. Eleven prospective and 11 case-control studies reported relative risk (RR estimates and 95% confidence intervals (CIs of PC associated with parity. Fixed- and random-effects models were used to estimate the summary RR depending on the heterogeneity of effects. RESULTS: The summary RR for PC comparing the highest versus lowest parity was 0.86 (95% CI: 0.73-1.02; Q = 50.49, P<0.001, I2 = 58.4%. Significant inverse associations were also observed in the studies that adjusted for cigarette smoking (RR = 0.81; 95% CI: 0.68-0.98, Type 2 diabetes mellitus (RR = 0.83; 95% CI: 0.75-0.93, and those that included all confounders or important risk factors (RR = 0.85; 95% CI: 0.76-0.96. Additionally, in the dose-response analysis, the summary RR for per one live birth was 0.97 (95% CI: 0.94-1.01; Q = 62.83, P<0.001, I2 = 69.8%, which also indicated a borderline statistically significant inverse effect of parity on PC risk. No evidence of publication bias and significant heterogeneity between subgroups were detected by meta-regression analyses. CONCLUSION: In summary, these findings suggest that higher parity is associated with a decreased risk of PC. Future large consortia or pooled studies are warranted to fully adjust for potential confounders to confirm this association.

  4. Doses to organs at cerebral risks: optimization by robotized stereotaxic radiotherapy and automatic segmentation atlas versus three dimensional conformal radiotherapy

    International Nuclear Information System (INIS)

    Bondiau, P.Y.; Thariat, J.; Benezery, K.; Herault, J.; Dalmasso, C.; Marcie, S.; Malandain, G.

    2007-01-01

    The stereotaxic radiotherapy robotized by 'Cyberknife fourth generation' allows a dosimetric optimization with a high conformity index on the tumor and radiation doses limited on organs at risk. A cerebral automatic anatomic segmentation atlas of organs at risk are used in routine in three dimensions. This study evaluated the superiority of the stereotaxic radiotherapy in comparison with the three dimensional conformal radiotherapy on the preservation of organs at risk in regard of the delivered dose to tumors justifying an accelerated hypo fractionation and a dose escalation. This automatic segmentation atlas should allow to establish correlations between anatomy and cerebral dosimetry; This atlas allows to underline the dosimetry optimization by stereotaxic radiotherapy robotized for organs at risk. (N.C.)

  5. Dose-response characteristics of low- and intermediate-risk prostate cancer treated with external beam radiotherapy

    International Nuclear Information System (INIS)

    Cheung, Rex; Tucker, Susan L.; Lee, Andrew K.; Crevoisier, Renaud de; Dong Lei; Kamat, Ashish; Pisters, Louis; Kuban, Deborah

    2005-01-01

    Purpose: In this era of dose escalation, the benefit of higher radiation doses for low-risk prostate cancer remains controversial. For intermediate-risk patients, the data suggest a benefit from higher doses. However, the quantitative characterization of the benefit for these patients is scarce. We investigated the radiation dose-response relation of tumor control probability in low-risk and intermediate-risk prostate cancer patients treated with radiotherapy alone. We also investigated the differences in the dose-response characteristics using the American Society for Therapeutic Radiology and Oncology (ASTRO) definition vs. an alternative biochemical failure definition. Methods and materials: This study included 235 low-risk and 387 intermediate-risk prostate cancer patients treated with external beam radiotherapy without hormonal treatment between 1987 and 1998. The low-risk patients had 1992 American Joint Committee on Cancer Stage T2a or less disease as determined by digital rectal examination, prostate-specific antigen (PSA) levels of ≤10 ng/mL, and biopsy Gleason scores of ≤6. The intermediate-risk patients had one or more of the following: Stage T2b-c, PSA level of ≤20 ng/mL but >10 ng/mL, and/or Gleason score of 7, without any of the following high-risk features: Stage T3 or greater, PSA >20 ng/mL, or Gleason score ≥8. The logistic models were fitted to the data at varying points after treatment, and the dose-response parameters were estimated. We used two biochemical failure definitions. The ASTRO PSA failure was defined as three consecutive PSA rises, with the time to failure backdated to the mid-point between the nadir and the first rise. The second biochemical failure definition used was a PSA rise of ≥2 ng/mL above the current PSA nadir (CN + 2). The failure date was defined as the time at which the event occurred. Local, nodal, and distant relapses and the use of salvage hormonal therapy were also failures. Results: On the basis of the

  6. Low-Dose-Rate Brachytherapy Versus Cryotherapy in Low- and Intermediate-Risk Prostate Cancer

    International Nuclear Information System (INIS)

    Gestaut, Matthew M.; Cai, Wendi; Vyas, Shilpa; Patel, Belur J.; Hasan, Salman A.; MunozMaldonado, Yolanda; Deb, Niloyjyoti; Swanson, Gregory

    2017-01-01

    Purpose: Cryotherapy and brachytherapy are definitive local treatment options for low- to intermediate-risk prostate cancer. There are both prospective and retrospective data for brachytherapy, but the use of cryotherapy has been limited primarily to single-institution retrospective studies. Currently, no published evidence has compared low-dose-rate brachytherapy versus cryotherapy. Methods and Materials: Institutional review board approval was obtained to conduct a retrospective chart review of consecutive patients treated at our institution from 1990 to 2012. For inclusion, patients must have received a prostate cancer diagnosis and have been considered to have low- to intermediate-risk disease according to the National Comprehensive Cancer Network criteria. All patients received brachytherapy or cryotherapy treatment. Disease specifics and failure details were collected for all patients. Failure was defined as prostate-specific antigen nadir +2 ng/mL. Results: A total of 359 patients were analyzed. The groups comprised 50 low-risk cryotherapy (LRC), 92 intermediate-risk cryotherapy (IRC), 133 low-risk brachytherapy (LRB), and 84 intermediate-risk brachytherapy (IRB) patients. The median prostate-specific antigen follow-up periods were 85.6 months (LRC), 59.2 months (IRC), 74.9 months (LRB), and 59.8 months (IRB). The 5-year biochemical progression–free survival (bPFS) rate was 57.9% in the cryotherapy group versus 89.6% in the brachytherapy group (P<.0001). The 5-year bPFS rate was 70.0% (LRC), 51.4% (IRC), 89.4% (LRB), and 89.7% (IRB). The bPFS rate was significantly different between brachytherapy and cryotherapy for low- and intermediate-risk groups (P<.05). The mean nadir temperature reached for cryotherapy patients was −35°C (range, −96°C to −6°C). Cryotherapy used a median of 2 freeze-thaw cycles (range, 2-4 freeze-thaw cycles). Conclusions: Results from this study suggest that cryotherapy is inferior to brachytherapy for patients with

  7. Low-Dose-Rate Brachytherapy Versus Cryotherapy in Low- and Intermediate-Risk Prostate Cancer.

    Science.gov (United States)

    Gestaut, Matthew M; Cai, Wendi; Vyas, Shilpa; Patel, Belur J; Hasan, Salman A; MunozMaldonado, Yolanda; Deb, Niloyjyoti; Swanson, Gregory

    2017-05-01

    Cryotherapy and brachytherapy are definitive local treatment options for low- to intermediate-risk prostate cancer. There are both prospective and retrospective data for brachytherapy, but the use of cryotherapy has been limited primarily to single-institution retrospective studies. Currently, no published evidence has compared low-dose-rate brachytherapy versus cryotherapy. Institutional review board approval was obtained to conduct a retrospective chart review of consecutive patients treated at our institution from 1990 to 2012. For inclusion, patients must have received a prostate cancer diagnosis and have been considered to have low- to intermediate-risk disease according to the National Comprehensive Cancer Network criteria. All patients received brachytherapy or cryotherapy treatment. Disease specifics and failure details were collected for all patients. Failure was defined as prostate-specific antigen nadir +2 ng/mL. A total of 359 patients were analyzed. The groups comprised 50 low-risk cryotherapy (LRC), 92 intermediate-risk cryotherapy (IRC), 133 low-risk brachytherapy (LRB), and 84 intermediate-risk brachytherapy (IRB) patients. The median prostate-specific antigen follow-up periods were 85.6 months (LRC), 59.2 months (IRC), 74.9 months (LRB), and 59.8 months (IRB). The 5-year biochemical progression-free survival (bPFS) rate was 57.9% in the cryotherapy group versus 89.6% in the brachytherapy group (Pcryotherapy for low- and intermediate-risk groups (Pcryotherapy patients was -35°C (range, -96°C to -6°C). Cryotherapy used a median of 2 freeze-thaw cycles (range, 2-4 freeze-thaw cycles). Results from this study suggest that cryotherapy is inferior to brachytherapy for patients with low- to intermediate-risk prostate cancer. Patient selection criteria for consideration of cryotherapy and brachytherapy are similar in terms of anesthesia candidacy. Therefore, cryotherapy would not be recommended as a first-line local therapy for this particular

  8. Low-Dose-Rate Brachytherapy Versus Cryotherapy in Low- and Intermediate-Risk Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Gestaut, Matthew M., E-mail: Matthew.Gestaut@BSWHealth.org [Department of Radiation Oncology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States); Cai, Wendi [Department of Biostatistics, Baylor Scott and White Health, Temple, Texas (United States); Vyas, Shilpa [Department of Radiation Oncology, Swedish Cancer Institute, Seattle, Washington (United States); Patel, Belur J. [Department of Urology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States); Hasan, Salman A. [Department of Radiation Oncology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States); MunozMaldonado, Yolanda [Department of Biostatistics, Baylor Scott and White Health, Temple, Texas (United States); Deb, Niloyjyoti; Swanson, Gregory [Department of Radiation Oncology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States)

    2017-05-01

    Purpose: Cryotherapy and brachytherapy are definitive local treatment options for low- to intermediate-risk prostate cancer. There are both prospective and retrospective data for brachytherapy, but the use of cryotherapy has been limited primarily to single-institution retrospective studies. Currently, no published evidence has compared low-dose-rate brachytherapy versus cryotherapy. Methods and Materials: Institutional review board approval was obtained to conduct a retrospective chart review of consecutive patients treated at our institution from 1990 to 2012. For inclusion, patients must have received a prostate cancer diagnosis and have been considered to have low- to intermediate-risk disease according to the National Comprehensive Cancer Network criteria. All patients received brachytherapy or cryotherapy treatment. Disease specifics and failure details were collected for all patients. Failure was defined as prostate-specific antigen nadir +2 ng/mL. Results: A total of 359 patients were analyzed. The groups comprised 50 low-risk cryotherapy (LRC), 92 intermediate-risk cryotherapy (IRC), 133 low-risk brachytherapy (LRB), and 84 intermediate-risk brachytherapy (IRB) patients. The median prostate-specific antigen follow-up periods were 85.6 months (LRC), 59.2 months (IRC), 74.9 months (LRB), and 59.8 months (IRB). The 5-year biochemical progression–free survival (bPFS) rate was 57.9% in the cryotherapy group versus 89.6% in the brachytherapy group (P<.0001). The 5-year bPFS rate was 70.0% (LRC), 51.4% (IRC), 89.4% (LRB), and 89.7% (IRB). The bPFS rate was significantly different between brachytherapy and cryotherapy for low- and intermediate-risk groups (P<.05). The mean nadir temperature reached for cryotherapy patients was −35°C (range, −96°C to −6°C). Cryotherapy used a median of 2 freeze-thaw cycles (range, 2-4 freeze-thaw cycles). Conclusions: Results from this study suggest that cryotherapy is inferior to brachytherapy for patients with

  9. Dose - response relationship between noise exposure and the risk of occupational injury

    Directory of Open Access Journals (Sweden)

    Jin-Ha Yoon

    2015-01-01

    Full Text Available Many workers worldwide experience fatality and disability caused by occupational injuries. This study examined the relationship between noise exposure and occupational injuries at factories in Korea. A total of 1790 factories located in northern Gyeonggi Province, Korea was evaluated. The time-weighted average levels of dust and noise exposure were taken from Workplace Exposure Assessment data. Apart occupational injuries, sports events, traffic accidents, and other accidents occurring outside workplaces were excluded. The incidences of occupational injury in each factory were calculated by data from the Korea Workers′ Compensation and Welfare Services. Workplaces were classified according to the incidence of any occupational injuries (incident or nonincident workplaces, respectively. Workplace dust exposure was classified as 90 dB. Workplaces with high noise exposure were significantly associated with being incident workplaces, whereas workplaces with high dust exposure were not. The odds ratios (95% confidence intervals derived from a logistic regression model were 1.68 (1.27-2.24 and 3.42 (2.26-5.17 at 80-89 dB and ≥90 dB versus <80 dB. These associations remained significant when in a separate analysis according to high or low dust exposure level. Noise exposure increases the risk of occupational injury in the workplace. Furthermore, the risk of occupational injury increases with noise exposure level in a dose-response relationship. Therefore, strategies for reducing noise exposure level are required to decrease the risk of occupational injury.

  10. Can we avoid high levels of dose escalation for high-risk prostate cancer in the setting of androgen deprivation?

    Directory of Open Access Journals (Sweden)

    Shakespeare TP

    2016-05-01

    Full Text Available Thomas P Shakespeare,1,2 Shea W Wilcox,1 Noel J Aherne1,2 1Department of Radiation Oncology, North Coast Cancer Institute, 2Rural Clinical School, Faculty of Medicine, University of New South Wales, Coffs Harbour, NSW, Australia Aim: Both dose-escalated external beam radiotherapy (DE-EBRT and androgen deprivation therapy (ADT improve outcomes in patients with high-risk prostate cancer. However, there is little evidence specifically evaluating DE-EBRT for patients with high-risk prostate cancer receiving ADT, particularly for EBRT doses >74 Gy. We aimed to determine whether DE-EBRT >74 Gy improves outcomes for patients with high-risk prostate cancer receiving long-term ADT. Patients and methods: Patients with high-risk prostate cancer were treated on an institutional protocol prescribing 3–6 months neoadjuvant ADT and DE-EBRT, followed by 2 years of adjuvant ADT. Between 2006 and 2012, EBRT doses were escalated from 74 Gy to 76 Gy and then to 78 Gy. We interrogated our electronic medical record to identify these patients and analyzed our results by comparing dose levels. Results: In all, 479 patients were treated with a 68-month median follow-up. The 5-year biochemical disease-free survivals for the 74 Gy, 76 Gy, and 78 Gy groups were 87.8%, 86.9%, and 91.6%, respectively. The metastasis-free survivals were 95.5%, 94.5%, and 93.9%, respectively, and the prostate cancer-specific survivals were 100%, 94.4%, and 98.1%, respectively. Dose escalation had no impact on any outcome in either univariate or multivariate analysis. Conclusion: There was no benefit of DE-EBRT >74 Gy in our cohort of high-risk prostate patients treated with long-term ADT. As dose escalation has higher risks of radiotherapy-induced toxicity, it may be feasible to omit dose escalation beyond 74 Gy in this group of patients. Randomized studies evaluating dose escalation for high-risk patients receiving ADT should be considered. Keywords: radiotherapy, IMRT, dose

  11. Estimation of population dose and risk to holding assistants from veterinary X-ray examination in Japan

    International Nuclear Information System (INIS)

    Hashizume, Tadashi; Suganuma, Tunenori; Shida, Takuo

    1989-01-01

    For the estimation of the population doses and risks of stochastic effects to assistants who hold animals during veterinary X-ray examination, a random survey of hospitals and clinics was carried out concerning age distribution of such assistants by groups of facilities. The average organ and tissue dose per examination was evaluated from the experimental data using mean technical factors such as X-ray tube voltage, tube current and field size based on the results of a nationwide survey. The population doses to the assistants were calculated to be about 14 nSv per person per year for the genetically significant dose, 3.5 nSv per person per year for per caput mean marrow dose, 3.3 nSv for the leukemia significant dose and 4.5 nSv for the malignant significant dose, respectively. The total risk of stochastic effects to the Japanese population from holding assistants was estimated using population data and it was estimated to be less than one person per year, but the cancer risks to a number of the assistants were estimated to be more than 4 x 10 -5 . (author)

  12. Estimation of breast doses and breast cancer risk associated with repeated fluoroscopic chest examinations of women with tuberculosis

    International Nuclear Information System (INIS)

    Boice, J.D. Jr.; Rosenstein, M.; Trout, E.D.

    1978-01-01

    A methodology is presented to estimate cumulative breast dose and breast cancer risk for women exposed to repeated fluoroscopic chest examinations during air collapse therapy for pulmonary tuberculosis. Medical record abstraction, physician interview, patient contact, machine exposure measurements, and absorbed dose computations were combined to estimate average breast doses for 1047 Massachusetts women who were treated between 1930 and 1954. The methodology presented considers breast size and composition, patient orientation, x-ray field size and location, beam quality, type of examination, machine exposure rate, and exposure time during fluoroscopic examinations. The best estimate for the risk of radiation-induced cancer for the women living longer than 10 years after initial fluoroscopic exposure is 6.2 excess breast cancers per million woman-year-rad with 90% confidence limits of 2.8 and 10.7 cancers/10 6 WY-rad. When breast cancer risk is considered as a function of absorbed dose in the breast, instead of as a function of the number of fluoroscopic examinations, a linear dose--response relationship over the range of estimated doses is consistent with the data. However, because of the uncertainty due to small-sample variability and because of the wide range of assumptions regarding certain fluoroscopy conditions, other dose--response relationships are compatible with the data

  13. Randomized phase 2 study of low-dose decitabine vs low-dose azacitidine in lower-risk MDS and MDS/MPN.

    Science.gov (United States)

    Jabbour, Elias; Short, Nicholas J; Montalban-Bravo, Guillermo; Huang, Xuelin; Bueso-Ramos, Carlos; Qiao, Wei; Yang, Hui; Zhao, Chong; Kadia, Tapan; Borthakur, Gautam; Pemmaraju, Naveen; Sasaki, Koji; Estrov, Zeev; Cortes, Jorge; Ravandi, Farhad; Alvarado, Yesid; Komrokji, Rami; Sekeres, Mikkael A; Steensma, David P; DeZern, Amy; Roboz, Gail; Kantarjian, Hagop; Garcia-Manero, Guillermo

    2017-09-28

    Hypomethylating agents (HMAs) improve survival in patients with higher-risk myelodysplastic syndromes (MDS) but are less well-studied in lower-risk disease. We compared the safety and efficacy of low-dose decitabine vs low-dose azacitidine in this group of patients. Adults with low- or intermediate 1-risk MDS or MDS/myeloproliferative neoplasm (MPN), including chronic myelomonocytic leukemia, according to the International Prognostic Scoring System, were randomly assigned using a Bayesian adaptive design to receive either azacitidine 75 mg/m 2 intravenously/subcutaneously daily or decitabine 20 mg/m 2 intravenously daily for 3 consecutive days on a 28-day cycle. The primary outcome was overall response rate (ORR). Between November 2012 and February 2016, 113 patients were treated: 40 (35%) with azacitidine and 73 (65%) with decitabine. The median age was 70 years; 81% of patients were intermediate 1-risk patients. The median number of cycles received was 9. The ORRs were 70% and 49% ( P = .03) for patients treated with decitabine and azacitidine, respectively. Thirty-two percent of patients treated with decitabine became transfusion independent compared with 16% of patients treated with azacitidine ( P = .2). Cytogenetic response rates were 61% and 25% ( P = .02), respectively. With a median follow-up of 20 months, the overall median event-free survival was 18 months: 20 and 13 months for patients treated with decitabine and azacitidine, respectively ( P = .1). Treatment was well tolerated, with a 6-week mortality rate of 0%. The use of low-dose HMAs is safe and effective in patients with lower-risk MDS and MDS/MPN. Their effect on the natural history of lower-risk disease needs to be further studied. This trial was registered at clinicaltrials.gov (identifier NCT01720225). © 2017 by The American Society of Hematology.

  14. What do recent epidemiological studies tell us about the risk of cancer from radiation doses typical of diagnostic radiography?

    International Nuclear Information System (INIS)

    Harbron, R.W.

    2016-01-01

    The last five years have seen unprecedented efforts to gain further understanding of the cancer risks following exposure to radiation doses below 100 mGy. Research has focused on occupationally exposed groups, populations exposed to elevated background radiation levels and children undergoing computed tomography scans. This review summarises the main findings of these studies and discusses the implications for diagnostic radiography. On balance, recent studies strengthen the association between radiation exposure at diagnostic dose levels and the risk of developing cancer at low doses. Although subject to considerable uncertainties, the risks to patients and staff from exposure to X-rays at diagnostic dose levels appear to be small, but non-zero. Despite the improved statistical power of recent studies, a number of shortcomings are apparent. These include dosimetric uncertainties and the potential confounding effects of cancer pre-disposing conditions and pre-existing tumours. - Highlights: • The risk of cancer from radiation doses below around 100 mGy is uncertain. • A number of new studies have been published with reasonably high statistical power. • These studies strengthen the association between X-rays and cancer at low doses. • Large uncertainties remain, however.

  15. Patient- and cohort-specific dose and risk estimation for abdominopelvic CT: a study based on 100 patients

    Science.gov (United States)

    Tian, Xiaoyu; Li, Xiang; Segars, W. Paul; Frush, Donald P.; Samei, Ehsan

    2012-03-01

    The purpose of this work was twofold: (a) to estimate patient- and cohort-specific radiation dose and cancer risk index for abdominopelvic computer tomography (CT) scans; (b) to evaluate the effects of patient anatomical characteristics (size, age, and gender) and CT scanner model on dose and risk conversion coefficients. The study included 100 patient models (42 pediatric models, 58 adult models) and multi-detector array CT scanners from two commercial manufacturers (LightSpeed VCT, GE Healthcare; SOMATOM Definition Flash, Siemens Healthcare). A previously-validated Monte Carlo program was used to simulate organ dose for each patient model and each scanner, from which DLP-normalized-effective dose (k factor) and DLP-normalized-risk index values (q factor) were derived. The k factor showed exponential decrease with increasing patient size. For a given gender, q factor showed exponential decrease with both increasing patient size and patient age. The discrepancies in k and q factors across scanners were on average 8% and 15%, respectively. This study demonstrates the feasibility of estimating patient-specific organ dose and cohort-specific effective dose and risk index in abdominopelvic CT requiring only the knowledge of patient size, gender, and age.

  16. Whole-body CT for lymphoma staging: Feasibility of halving radiation dose and risk by iterative image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M., E-mail: mathias.meyer@medma.uni-heidelberg.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Klein, S.A., E-mail: stefan.klein@umm.de [Department of Hematology and Oncology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Brix, G., E-mail: gbrix@bfs.de [Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany); Fink, C., E-mail: Christian.Fink@medma.uni-heidelberg.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Pilz, L., E-mail: lothar.pilz@medma.uni-heidelberg.de [Department of Biostatistics, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Jafarov, H., E-mail: Hashim.Jafarov@umm.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Hofmann, W.K., E-mail: w.k.hofmann@umm.de [Department of Hematology and Oncology, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Schoenberg, S.O., E-mail: Stefan.Schoenberg@umm.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); and others

    2014-02-15

    Objectives: Patients with lymphoma are at higher-risk of secondary malignancies mainly due to effects of cancer therapy as well as frequent radiological surveillance. We thus aimed to investigate the objective and subjective image quality as well as radiation exposure and risk of full-dose standard (FDS), full-dose iterative (FDI), and half-dose iterative (HDI) image reconstruction in patients with lymphoma. Material and methods: In 100 lymphoma patients, contrast-enhanced whole-body staging was performed on a dual-source CT. To acquire full-dose and half-dose CT data simultaneously, the total current-time product was equally distributed on both tubes operating at 120 kV. HDI reconstructions were calculated by using only data from one tube. Quantitative image quality was assessed by measuring image noise in different tissues of the neck, thorax, and abdomen. Overall diagnostic image quality was assessed using a 5-point Likert scale. Radiation doses and risks were estimated for a male and female reference person. Results: For all anatomical regions apart from the lungs image noise was significantly lower and the overall subjective image quality significantly better when using FDI and HDI instead of FDS reconstruction (p < 0.05). For the half-dose protocol, the risk to develop a radiation-induced cancer was estimated to be less than 0.11/0.19% for an adult male/female. Conclusions: Image quality of FDI and more importantly of HDI is superior to FDS reconstruction, thus enabling to halve radiation dose and risk to lymphoma patients.

  17. Staggering the dose of sugammadex lowers risks for severe emergence cough: a randomized control trial.

    Science.gov (United States)

    P S, Loh; Miskan, M M; Y Z, Chin; Zaki, R A

    2017-10-11

    Cough on emergence has been reported as a common adverse reaction with sugammadex reversal. We investigated if staggering the dose of sugammadex will reduce emergence cough in a single-center, randomized, double-blinded study. A hundred and twenty ASA 1-3 adults were randomly reversed with 1 mg/kg sugammadex prior to extubation followed by another 1 mg/kg immediately after extubation (staggered group), single dose of 2 mg/kg sugammadex (single bolus group) or neostigmine 0.02 mg/kg with glycopyrrolate (neostigmine group). We found 70% of patients (n = 28) reversed with single boluses of sugammadex had Grade 3 emergence cough compared to 12.5% (n = 5) in the staggered sugammadex group and 17.5% (n = 7) in the neostigmine group (p sugammadex group (n = 14, 35%, p = 0.005). On the other hand, staggering sugammadex lowered risks of developing severe cough (RR 0.2, p sugammadex group and control given neostigmine. In terms of timing, there was no delay in time taken from discontinuing anesthetic agents to reversal and extubation if sugammadex was staggered (emergence time 6.0 ± 3.2 s, p = 0.625 and reversal time 6.5 ± 3.5, p = 0.809). Staggering the dose of sugammadex for reversal will effectively decrease common emergence and early postoperative complications. ANZCTR Number ACTRN12616000116426 . Retrospectively registered on 2nd February 2016.

  18. Teratogenic radiation effects: Phenomena, dose-response relationships and risk levels

    International Nuclear Information System (INIS)

    Konermann, G.

    1991-01-01

    The report in hand informs about a study performed within the framework of the research project 'Animal experiments with albino mice for establishing a model for the detection and assessment of radiation-induced, developmental risks in man due to low-dose irradiation'. The subjects investigated in this study are: (1) Dose-response relationships for postnatal developmental disturbances of the brain as a result of prenatal X-ray treatment. (2) Biokinetics, distribution patterns and effects of inorganically and organically bonded radioiodine (I-125) during the phase of development of the brain. For investigation of the first-mentioned subject, computerized microphotograph analysis was applied for detecting and assessing disturbances of the alignment of axons, as well as deviations from normal cross-sectional data of the Cortex layer, and cerebral commissures as final locations of neurogenetic damage. With all parameters studied, the slope of the relevant curves was found to decrease as a function of age of the fetus at the time of exposure. In addition, time factor effects were investigated. For the parameter cross-sectional area of the Cortex, a clear decrease of effect was found, but for all other parameters, reactions were ambiguous. The study into the second subject was done with cell cultures, showing that the I-125 bonded to the cell nucleus has a much stronger radiotoxic effect than I-125 bonded to the cytoplasma. This difference in effect was studied in mice after incorporation of equal doses administered by way of (I-125)-sodium iodide or (I-125)-iododesoxyuridine. Long-term effects on Cortex cross-sectional areas, cerebral commissures or the texture of axons were quantified by microphotograph analysis. Acute cell death and initial disturbances of the neuronal cell growth were evident after incorporation of (I-125)-IdUR, but not detectable after administration of (I-125)-NaI. (orig./MG) [de

  19. Dose evaluation and risk estimation for secondary cancer in contralateral breast and a study of correlation between thorax shape and dose to organs at risk following tangentially breast irradiation during deep inspiration breath-hold and free breathing

    International Nuclear Information System (INIS)

    Johansen, Safora; Vikstroem, Johan; Blihovde Hjelstuen, Mari Helene; Mjaaland, Ingvil; Dybvik, Kjell Ivar; Olsen, Dag Rune

    2011-01-01

    Purpose: To assess the impact of using breathing adapted radiotherapy on contralateral breast (CB) dose, to relate the thorax shape with the dose to the organs at risk (OARs) and to predict the risk for induced malignancies in CB using linear and non-linear models, following tangential irradiation of breast. Material and methods. Sixteen patients with stage I-II breast cancer treatment planned with tangential fields using deep inspiration breath hold (DIBH) and free breathing (FB) techniques were included in this analysis. The dose results mainly based on DVH analysis were compared. Four parameters were defined to describe thoracic shape. Excess relative risk (ERR) for cancer induction in CB, employing linear and non-linear models was calculated. Results. Average CB volumes exposed to a dose of 1 Gy is 1.3 times higher in DIBH plans than in FB plans. No significant difference in average V3Gy and V5Gy for DIBH and FB plans is observed. The average mean CB dose for DIBH and FB plans is 0.33 and 0.28 Gy, respectively. No correlation between thorax shape parameters and mean OARs dose is observed. The estimated average mean ERR with linear model is lower in FB plans (0.12) than for the DIBH plans (0.14). The estimated ERR with non-linear model is 0.14 for DIBH plans and 0.15 for FB plans. Conclusion. No significant difference in CB dose between DIBH and FB plans is observed. The four thorax shape parameters defined in this study can not be related to the dose at OARs using DIBH and FB radiation techniques. The ERR estimates for secondary CB cancer are nearly the same for FB and DIBH planning when using a linear and non-linear risk prediction models

  20. Non-targeted effects of ionising radiation—Implications for low dose risk

    DEFF Research Database (Denmark)

    Kadhim, Munira; Salomaa, Sisko; Wright, Eric

    2013-01-01

    and adaptive responses are powered by fundamental, but not clearly understood systems that maintain tissue homeostasis. Despite excellent research in this field by various groups, there are still gaps in our understanding of the likely mechanisms associated with non-DNA targeted effects, particularly......Non-DNA targeted effects of ionising radiation, which include genomic instability, and a variety of bystander effects including abscopal effects and bystander mediated adaptive response, have raised concerns about the magnitude of low-dose radiation risk. Genomic instability, bystander effects....... Furthermore, it is still not known what the initial target and early interactions in cells are that give rise to non-targeted responses in neighbouring or descendant cells. This paper provides a commentary on the current state of the field as a result of the non-targeted effects of ionising radiation (NOTE...

  1. The ICRP opinion of the calculation of doses and risks associated with exposures to tritium

    International Nuclear Information System (INIS)

    Paquetla, F.; Harrison, J.

    2009-01-01

    As the management of exposures to tritium, just like for other radionuclides, relies on the effective dose calculation, it also requires the application of coefficients to take the variety of radiations and the sensitivity of the different irradiated tissues into account. The authors discuss the determination and the use of the weighting factor (Wr) which reflects the relative biological effectiveness (RBE) of different types of radiation. They outline that some researchers asked for a review of this factor, and that the RBE is related to several parameters. All this and other issues entail uncertainties. The authors then give the opinion of the ICRP on this issue and notably for the assessment of the individual risk of cancer after exposure to tritium

  2. The Radiobiological Basis for Improvements in Radiotherapy and Low Dose Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hei, Tom K. [Columbia Univ., New York, NY (United States)

    2009-12-09

    This conference grant was proposed to organize and host an international conference at Columbia University in New York to critically assess the cellular and molecular signaling events and tissue response following radiation damage. The conference would also serve as a venue to play tribute to the more than forty years contributions made by Professor Eric J. Hall to the radiation biology field. The goals of the meeting were to examine tumor hypoxia and sensitizer development; recent advances made in clinical radiotherapy; addressed several low dose phenomena, including genomic instability and bystander effects that are important in radiation risk assessment. Study and Results: The symposium was held on October 13th and 14th, 2008 at the Alfred Lerner Hall in the Morningside campus of Columbia University. The symposium, entitled “From Beans to Genes: A Forty Year Odyssey in Radiation Biology” was attended by more than 120 faculty, scientists, clinicians, fellows and students. The symposium, spanned over a day and a half, covered four scientific themes. These included tumor hypoxia and radiosensitizers; low dose radiation response; radiation biology in the practice of radiotherapy, and radiation hazard in space and genetic predisposition to cancer. The program of the symposium is as follow:

  3. Molecular alterations in childhood thyroid cancer after Chernobyl accident and low-dose radiation risk

    International Nuclear Information System (INIS)

    Suzuki, Keiji; Mitsutake, Norisato; Yamashita, Shunichi

    2012-01-01

    The linear no-threshold (LNT) model of radiation carcinogenesis has been used for evaluating the risk from radiation exposure. While the epidemiological studies have supported the LNT model at doses above 100 mGy, more uncertainties are still existed in the LNT model at low doses below 100 mGy. Thus, it is urged to clarify the molecular mechanisms underlying radiation carcinogenesis. After the Chernobyl accident in 1986, significant amount of childhood thyroid cancer has emerged in the children living in the contaminated area. As the incidence of sporadic childhood thyroid cancer is very low, it is quite evident that those cancer cases have been induced by radiation exposure caused mainly by the intake of contaminated foods, such as milk. Because genetic alterations in childhood thyroid cancers have extensively been studied, it should provide a unique chance to understand the molecular mechanisms of radiation carcinogenesis. In a current review, molecular signatures obtained from the molecular studies of childhood thyroid cancer after Chernobyl accident have been overviewed, and new roles of radiation exposure in thyroid carcinogenesis will be discussed. (author)

  4. Radon Sources and Associated Risk in terms of Exposure and Dose

    Directory of Open Access Journals (Sweden)

    Efstratios Gregory Vogiannis

    2015-01-01

    Full Text Available Radon concern the international scientific community from early 20th century. Initially as radium emanation, almost the second half of the century as severe harmful to human health. Initial brilliant period of use as medicine, followed by a period of intense concern for its health effects. Primary target groups surveyed were miners early in Europe later in U.S. There is now compelling evidence that radon and its progeny can cause lung cancer. Human activities may create or modify pathways increasing indoor radon concentration compared to outdoor background. These pathways can be controlled by preventive and corrective actions. Indoor Radon and its short-lived progeny attached on aerosol particles or free compose an air mixture that carry a significant energy amount (PAEC. Exposure on PAEC and dose delivered reviewed in detail. Special attention was paid to the case of water workers because lack of adequate data. Radon risk assessment and current legislation regulates dose from radon and its progeny, also were reviewed.

  5. High biologically effective dose radiation therapy using brachytherapy in combination with external beam radiotherapy for high-risk prostate cancer

    Directory of Open Access Journals (Sweden)

    Keisei Okamoto

    2017-02-01

    Full Text Available Purpose : To evaluate the outcomes of high-risk prostate cancer patients treated with biologically effective dose (BED ≥ 220 Gy of high-dose radiotherapy, using low-dose-rate (LDR brachytherapy in combination with external beam radiotherapy (EBRT and short-term androgen deprivation therapy (ADT. Material and methods : From 2005 to 2013, a total of 143 patients with high-risk prostate cancer were treated by radiotherapy of BED ≥ 220 Gy with a combination of LDR brachytherapy, EBRT, and androgen deprivation therapy (ADT. The high-risk patients in the present study included both high-risk and very high-risk prostate cancer. The number of high-risk features were: 60 patients with 1 high-risk factor (42%, 61 patients with 2 high-risk factors (43%, and 22 patients with 3 high-risk factors (15% including five N1 disease. External beam radiotherapy fields included prostate and seminal vesicles only or whole pelvis depending on the extension of the disease. Biochemical failure was defined by the Phoenix definition. Results : Six patients developed biochemical failure, thus providing a 5-year actual biochemical failure-free survival (BFFS rate of 95.2%. Biochemical failure was observed exclusively in cases with distant metastasis in the present study. All six patients with biochemical relapse had clinical failure due to bone metastasis, thus yielding a 5-year freedom from clinical failure (FFCF rate of 93.0%. None of the cases with N1 disease experienced biochemical failure. We observed four deaths, including one death from prostate cancer, therefore yielding a cause-specific survival (CSS rate of 97.2%, and an overall survival (OS rate of 95.5%. Conclusions : High-dose (BED ≥ 220 Gy radiotherapy by LDR in combination with EBRT has shown an excellent outcome on BFFS in high-risk and very high-risk cancer, although causal relationship between BED and BFFS remain to be explained further.

  6. Low Radiation Dose and Low Cell Dose Increase the Risk of Graft Rejection in a Canine Hematopoietic Stem Cell Transplantation Model.

    Science.gov (United States)

    Lange, Sandra; Steder, Anne; Glass, Änne; Killian, Doreen; Wittmann, Susanne; Machka, Christoph; Werner, Juliane; Schäfer, Stephanie; Roolf, Catrin; Junghanss, Christian

    2016-04-01

    The canine hematopoietic stem cell transplantation (HSCT) model has become accepted in recent decades as a good preclinical model for the development of new transplantation strategies. Information on factors associated with outcome after allogeneic HSCT are a prerequisite for designing new risk-adapted transplantation protocols. Here we report a retrospective analysis aimed at identifying risk factors for allograft rejection in the canine HSCT model. A total of 75 dog leukocyte antigen-identical sibling HSCTs were performed since 2003 on 10 different protocols. Conditioning consisted of total body irradiation at 1.0 Gy (n = 20), 2.0 Gy (n = 40), or 4.5 Gy (n = 15). Bone marrow was infused either intravenously (n = 54) or intraosseously (n = 21). Cyclosporin A alone or different combinations of cyclosporine A, mycophenolate mofetil, and everolimus were used for immunosuppression. A median cell dose of 3.5 (range, 1.0 to 11.8) total nucleated cells (TNCs)/kg was infused. Cox analyses were used to assess the influence of age, weight, radiation dose, donor/recipient sex, type of immunosuppression, and cell dose (TNCs, CD34(+) cells) on allograft rejection. Initial engraftment occurred in all dogs. Forty-two dogs (56%) experienced graft rejection at median of 11 weeks (range, 6 to 56 weeks) after HSCT. Univariate analyses revealed radiation dose, type of immunosuppression, TNC dose, recipient weight, and recipient age as factors influencing long-term engraftment. In multivariate analysis, low radiation dose (P rejection. Peripheral blood mononuclear cell chimerism ≥30% (P = .008) and granulocyte chimerism ≥70% (P = .023) at 4 weeks after HSCT were independent predictors of stable engraftment. In summary, these data indicate that even in low-dose total body irradiation-based regimens, the irradiation dose is important for engraftment. The level of blood chimerism at 4 weeks post-HSCT was predictive of long-term engraftment in the canine HSCT

  7. High Dose Atorvastatin Associated with Increased Risk of Significant Hepatotoxicity in Comparison to Simvastatin in UK GPRD Cohort.

    Directory of Open Access Journals (Sweden)

    Alan T Clarke

    Full Text Available Occasional risk of serious liver dysfunction and autoimmune hepatitis during atorvastatin therapy has been reported. We compared the risk of hepatotoxicity in atorvastatin relative to simvastatin treatment.The UK GPRD identified patients with a first prescription for simvastatin [164,407] or atorvastatin [76,411] between 1997 and 2006, but with no prior record of liver disease, alcohol-related diagnosis, or liver dysfunction. Incident liver dysfunction in the following six months was identified by biochemical value and compared between statin groups by Cox regression model adjusting for age, sex, year treatment started, dose, alcohol consumption, smoking, body mass index and comorbid conditions.Moderate to severe hepatotoxicity [bilirubin >60μmol/L, AST or ALT >200U/L or alkaline phosphatase >1200U/L] developed in 71 patients on atorvastatin versus 101 on simvastatin. Adjusted hazard ratio [AHR] for all atorvastatin relative to simvastatin was 1.9 [95% confidence interval 1.4-2.6]. High dose was classified as 40-80mg daily and low dose 10-20mg daily. Hepatotoxicity occurred in 0.44% of 4075 patients on high dose atorvastatin [HDA], 0.07% of 72,336 on low dose atorvastatin [LDA], 0.09% of 44,675 on high dose simvastatin [HDS] and 0.05% of 119,732 on low dose simvastatin [LDS]. AHRs compared to LDS were 7.3 [4.2-12.7] for HDA, 1.4 [0.9-2.0] for LDA and 1.5 [1.0-2.2] for HDS.The risk of hepatotoxicity was increased in the first six months of atorvastatin compared to simvastatin treatment, with the greatest difference between high dose atorvastatin and low dose simvastatin. The numbers of events in the analyses were small.

  8. High Dose Atorvastatin Associated with Increased Risk of Significant Hepatotoxicity in Comparison to Simvastatin in UK GPRD Cohort

    Science.gov (United States)

    Clarke, Alan T.; Johnson, Paul C. D.; Hall, Gillian C.; Ford, Ian; Mills, Peter R.

    2016-01-01

    Background & Aims Occasional risk of serious liver dysfunction and autoimmune hepatitis during atorvastatin therapy has been reported. We compared the risk of hepatotoxicity in atorvastatin relative to simvastatin treatment. Methods The UK GPRD identified patients with a first prescription for simvastatin [164,407] or atorvastatin [76,411] between 1997 and 2006, but with no prior record of liver disease, alcohol-related diagnosis, or liver dysfunction. Incident liver dysfunction in the following six months was identified by biochemical value and compared between statin groups by Cox regression model adjusting for age, sex, year treatment started, dose, alcohol consumption, smoking, body mass index and comorbid conditions. Results Moderate to severe hepatotoxicity [bilirubin >60μmol/L, AST or ALT >200U/L or alkaline phosphatase >1200U/L] developed in 71 patients on atorvastatin versus 101 on simvastatin. Adjusted hazard ratio [AHR] for all atorvastatin relative to simvastatin was 1.9 [95% confidence interval 1.4–2.6]. High dose was classified as 40–80mg daily and low dose 10–20mg daily. Hepatotoxicity occurred in 0.44% of 4075 patients on high dose atorvastatin [HDA], 0.07% of 72,336 on low dose atorvastatin [LDA], 0.09% of 44,675 on high dose simvastatin [HDS] and 0.05% of 119,732 on low dose simvastatin [LDS]. AHRs compared to LDS were 7.3 [4.2–12.7] for HDA, 1.4 [0.9–2.0] for LDA and 1.5 [1.0–2.2] for HDS. Conclusions The risk of hepatotoxicity was increased in the first six months of atorvastatin compared to simvastatin treatment, with the greatest difference between high dose atorvastatin and low dose simvastatin. The numbers of events in the analyses were small. PMID:26983033

  9. Cancer and non-cancer risk at low doses of radiation: biological basis of radiation-environment interplay

    International Nuclear Information System (INIS)

    Sasaki, Masao S.

    2013-01-01

    Cancer and non-cancer risk at low doses of ionizing radiation remains poorly defined due to ambiguity at low doses caused by limitations in statistical power and information available on interplay with environment. To deal with these problems, a novel non-parametric statistics was developed based on artificial neural networks theorem and applied to cancer and non-cancer risk in A-bomb survivors. The analysis revealed several unique features at low doses that could not be accounted for by nominal radiation dose alone. They include (1) threshold that varies with organ, gender and age, including cardiovascular diseases, (2) prevalence of infectious diseases, and (3) suppression of pathogenesis of HTLV1. The threshold is unique as it is manifested as negative excess relative risk, a reduction of spontaneous rate at low doses. The response is consistent with currently emerging laboratory data on DNA double-strand break (DSB) repair pathway choice and its sustainability as epigenetic memory in accordance with histone code theory. In response to DSB, of radiation or DNA replication arrest origin, distinct and competitively operating repair pathways are instigated. Activation by low doses of restitution-directed canonical non-homologous end-joining (C-NHEJ) suppresses both error-prone alternative end-joining (Alt-NHEJ) and homologous recombination (HR). The latter two present major pathways to mutagenesis at stalled replication folk associated with endogenous and exogenous genotoxin such as tobacco smoke metabolites and AID-associated somatic hypermutation and class switch recombination in Ig gene. Suppression of these error-prone pathways by low doses of low LET radiation is consistent with the reduction of cancer occurrence by environmental genotoxin, immunodiversity and stable integration of retrovirus DNA, providing a significant modulator of dose linearity at low doses. Whole picture may bring about a new landscape of cancer and non-cancer molecular epidemiology which

  10. A methodology for estimating potential doses and risks from recycling U.S. Department of Energy radioactive scrap metals

    International Nuclear Information System (INIS)

    MacKinney, J.A.

    1995-01-01

    The U.S. Environmental Protection Agency (EPA) is considering writing regulations for the controlled use of materials originating from radioactively contaminated zones which may be recyclable. These materials include metals, such as steel (carbon and stainless), nickel, copper, aluminum and lead, from the decommissioning of federal, and non-federal facilities. To develop criteria for the release of such materials, a risk analysis of all potential exposure pathways should be conducted. These pathways include direct exposure to the recycled material by the public and workers, both individual and collective, as well as numerous other potential exposure pathways in the life of the material. EPA has developed a risk assessment methodology for estimating doses and risks associated with recycling radioactive scrap metals. This methodology was applied to metal belonging to the U.S. Department of Energy. This paper will discuss the draft EPA risk assessment methodology as a tool for estimating doses and risks from recycling. (author)

  11. Out-of-field organ doses and associated radiogenic risks from para-aortic radiotherapy for testicular seminoma

    Energy Technology Data Exchange (ETDEWEB)

    Mazonakis, Michalis, E-mail: mazonak@med.uoc.gr; Berris, Theocharis; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P. O. Box 2208, 71003 Iraklion, Crete (Greece); Varveris, Charalambos; Lyraraki, Efrossyni [Department of Radiotherapy and Oncology, University Hospital of Iraklion, 71110 Iraklion, Crete (Greece)

    2014-05-15

    Purpose: The aims of this study were to (a) calculate the radiation dose to out-of-field organs from radiotherapy for stage I testicular seminoma and (b) estimate the associated radiogenic risks. Methods: Monte Carlo methodology was employed to model radiation therapy with typical anteroposterior and posteroanterior para-aortic fields on an anthropomorphic phantom simulating an average adult. The radiation dose received by all main and remaining organs that defined by the ICRP publication 103 and excluded from the treatment volume was calculated. The effect of field dimensions on each organ dose was determined. Additional therapy simulations were generated by introducing shielding blocks to protect the kidneys from primary radiation. The gonadal dose was employed to assess the risk of heritable effects for irradiated male patients of reproductive potential. The lifetime attributable risks (LAR) of radiotherapy-induced cancer were estimated using gender- and organ-specific risk coefficients for patient ages of 20, 30, 40, and 50 years old. The risk values were compared with the respective nominal risks. Results: Para-aortic irradiation to 20 Gy resulted in out-of-field organ doses of 5.0–538.6 mGy. Blocked field treatment led to a dose change up to 28%. The mean organ dose variation by increasing or decreasing the applied field dimensions was 18.7% ± 3.9% and 20.8% ± 4.5%, respectively. The out-of-field photon doses increased the lifetime intrinsic risk of developing thyroid, lung, bladder, prostate, and esophageal cancer by (0.1–1.4)%, (0.4–1.1)%, (2.5–5.4)%, (0.2–0.4)%, and (6.4–9.2)%, respectively, depending upon the patient age at exposure and the field size employed. A low risk for heritable effects of less than 0.029% was found compared with the natural incidence of these defects. Conclusions: Testicular cancer survivors are subjected to an increased risk for the induction of bladder and esophageal cancer following para-aortic radiotherapy. The

  12. Utility of repeated praziquantel dosing in the treatment of schistosomiasis in high-risk communities in Africa: a systematic review.

    Directory of Open Access Journals (Sweden)

    Charles H King

    2011-09-01

    Full Text Available Controversy persists about the optimal approach to drug-based control of schistosomiasis in high-risk communities. In a systematic review of published studies, we examined evidence for incremental benefits from repeated praziquantel dosing, given 2 to 8 weeks after an initial dose, in Schistosoma-endemic areas of Africa.We performed systematic searches of electronic databases PubMed and EMBASE for relevant data using search terms 'schistosomiasis', 'dosing' and 'praziquantel' and hand searches of personal collections and bibliographies of recovered articles. In 10 reports meeting study criteria, improvements in parasitological treatment outcomes after two doses of praziquantel were greater for S. mansoni infection than for S. haematobium infection. Observed cure rates (positive to negative conversion in egg detection assays were, for S. mansoni, 69-91% cure after two doses vs. 42-79% after one dose and, for S. haematobium, 46-99% cure after two doses vs. 37-93% after a single dose. Treatment benefits in terms of reduction in intensity (mean egg count were also different for the two species-for S. mansoni, the 2-dose regimen yielded an weighted average 89% reduction in standardized egg counts compared to a 83% reduction after one dose; for S. haematobium, two doses gave a 93% reduction compared to a 94% reduction with a single dose. Cost-effectiveness analysis was performed based on Markov life path modeling.Although schedules for repeated treatment with praziquantel require greater inputs in terms of direct costs and community participation, there are incremental benefits to this approach at an estimated cost of $153 (S. mansoni-$211 (S. haematobium per additional lifetime QALY gained by double treatment in school-based programs. More rapid reduction of infection-related disease may improve program adherence, and if, as an externality of the program, transmission can be reduced through more effective coverage, significant additional benefits are

  13. Dose — response relationship between noise exposure and the risk of occupational injury

    Science.gov (United States)

    Yoon, Jin-Ha; Hong, Jeong-Suk; Roh, Jaehoon; Kim, Chi-Nyon; Won, Jong-Uk

    2015-01-01

    Many workers worldwide experience fatality and disability caused by occupational injuries. This study examined the relationship between noise exposure and occupational injuries at factories in Korea. A total of 1790 factories located in northern Gyeonggi Province, Korea was evaluated. The time-weighted average levels of dust and noise exposure were taken from Workplace Exposure Assessment data. Apart occupational injuries, sports events, traffic accidents, and other accidents occurring outside workplaces were excluded. The incidences of occupational injury in each factory were calculated by data from the Korea Workers’ Compensation and Welfare Services. Workplaces were classified according to the incidence of any occupational injuries (incident or nonincident workplaces, respectively). Workplace dust exposure was classified as 90 dB. Workplaces with high noise exposure were significantly associated with being incident workplaces, whereas workplaces with high dust exposure were not. The odds ratios (95% confidence intervals) derived from a logistic regression model were 1.68 (1.27-2.24) and 3.42 (2.26-5.17) at 80-89 dB and ≥90 dB versus occupational injury in the workplace. Furthermore, the risk of occupational injury increases with noise exposure level in a dose-response relationship. Therefore, strategies for reducing noise exposure level are required to decrease the risk of occupational injury. PMID:25599757

  14. Dose and risk assessment for intrusion into mixed waste disposal sites

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Aaberg, R.L.

    1991-10-01

    Sites previously used for disposal of radioactive and hazardous chemical materials have resulted in situations that pose a potential threat to humans from inadvertent intrusion. An example generic scenario analysis was developed to demonstrate the evaluation of potential exposure to either cleanup workers or members of the public who intrude into buried waste containing both radioactive and hazardous chemical contaminants. The example scenarios consist of a collection of exposure routes (or pathways) with specific modeling assumptions for well-drilling and for excavation to construct buildings. These scenarios are used to describe conceptually some potential patterns of activity by non-protected human beings during intrusion into mixed-waste disposal sites. The dose from exposure to radioactive materials is calculated using the GENII software system and converted to risk by using factors from ICRP Publication 60. The hazard assessment for nonradioactive materials is performed using recent guidelines from the US Environmental Protection Agency (EPA). The example results are in the form of cancer risk for carcinogens and radiation exposure

  15. An overview of the report: Correlation between carcinogenic potency and the maximum tolerated dose: Implications for risk assessment

    International Nuclear Information System (INIS)

    Krewski, D.; Gaylor, D.W.; Soms, A.P.; Szyszkowicz, M.

    1993-01-01

    Current practice in carcinogen bioassay calls for exposure of experimental animals at doses up to and including the maximum tolerated dose (MTD). Such studies have been used to compute measures of carcinogenic potency such as the TD 50 as well as unit risk factors such as q 1 for predicting low-dose risks. Recent studies have indicated that these measures of carcinogenic potency are highly correlated with the MTD. Carcinogenic potency has also been shown to be correlated with indicators of mutagenicity and toxicity. Correlation of the MTDs for rats and mice implies a corresponding correlation in TD 50 values for these two species. The implications of these results for cancer risk assessment are examined in light of the large variation in potency among chemicals known to induce tumors in rodents. 119 refs., 2 figs., 4 tabs

  16. Dose to the contralateral breast from radiotherapy and risk of second primary breast cancer in the WECARE study

    DEFF Research Database (Denmark)

    Stovall, M.; Smith, S.A.; Langholz, B.M.

    2008-01-01

    PURPOSE: To quantify the risk of second primary breast cancer in the contralateral breast (CB) after radiotherapy (RT) for first breast cancer. METHODS AND MATERIALS: The study population included participants in the Women's Environmental, Cancer, and Radiation Epidemiology study: 708 cases (women...... calculated using multivariable-adjusted conditional logistic regression models. RESULTS: Across all patients, the mean radiation dose to the specific quadrant of the CB tumor was 1.1 Gy. Women 1.0 Gy of absorbed dose to the specific quadrant of the CB had a 2.5-fold greater...... risk for CB cancer than unexposed women (RR = 2.5, 95% CI 1.4-4.5). No excess risk was observed in women >40 years of age. Women 5 years had a RR of 3.0 (95% CI 1.1-8.1), and the dose response was significant (excess RR per Gy of 1.0, 95% CI 0...

  17. Estimation of effective collective doses to population of Balti city with health risk assessment by means of medical radiodiagnostic irradiation

    International Nuclear Information System (INIS)

    Chislari, V.

    2009-01-01

    In this work the equivalent of effective collective dose, average annual of radio diagnostic researches in medicine for one habitant Belti city during 2006-2008 and a tendency was exposed to multiplying a dose due to multiplying the number of radiological researches was calculated. As compared to indexes for Republic of Moldova annual equivalent of effective dose is increased in 3 times. A potential risk of a medical radiation makes in 2006 - 7 cases of cancer, in 2007 - 8 cases and in 2009 - 9 cases. (author)

  18. Conformal irradiation of the prostate: estimating long-term rectal bleeding risk using dose-volume histograms

    International Nuclear Information System (INIS)

    Hartford, Alan C.; Niemierko, Andrzej; Adams, Judith A.; Urie, Marcia M.; Shipley, William U.

    1996-01-01

    Purpose: Dose-volume histograms (DVHs) may be very useful tools for estimating probability of normal tissue complications (NTCP), but there is not yet an agreed upon method for their analysis. This study introduces a statistical method of aggregating and analyzing primary data from DVHs and associated outcomes. It explores the dose-volume relationship for NTCP of the rectum, using long-term data on rectal wall bleeding following prostatic irradiation. Methods and Materials: Previously published data were reviewed and updated on 41 patients with Stages T3 and T4 prostatic carcinoma treated with photons followed by perineal proton boost, including dose-volume histograms (DVHs) of each patient's anterior rectal wall and data on the occurrence of postirradiation rectal bleeding (minimum FU > 4 years). Logistic regression was used to test whether some individual combination of dose and volume irradiated might best separate the DVHs into categories of high or low risk for rectal bleeding. Further analysis explored whether a group of such dose-volume combinations might be superior in predicting complication risk. These results were compared with results of the 'critical volume model', a mathematical model based on assumptions of underlying radiobiological interactions. Results: Ten of the 128 tested dose-volume combinations proved to be 'statistically significant combinations' (SSCs) distinguishing between bleeders (14 out of 41) and nonbleeders (27 out of 41), ranging contiguously between 60 CGE (Cobalt Gray Equivalent) to 70% of the anterior rectal wall and 75 CGE to 30%. Calculated odds ratios for each SSC were not significantly different across the individual SSCs; however, analysis combining SSCs allowed segregation of DVHs into three risk groups: low, moderate, and high. Estimates of probabilities of normal tissue complications (NTCPs) based on these risk groups correlated strongly with observed data (p = 0.003) and with biomathematical model-generated NTCPs

  19. Proton Radiotherapy for High-Risk Pediatric Neuroblastoma: Early Outcomes and Dose Comparison

    Energy Technology Data Exchange (ETDEWEB)

    Hattangadi, Jona A. [Harvard Radiation Oncology Program, Boston, MA (United States); Rombi, Barbara [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Provincial Agency for Proton Therapy, Trento (Italy); Yock, Torunn I.; Broussard, George [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Friedmann, Alison M.; Huang, Mary [Department of Pediatric Hematology-Oncology, Massachusetts General Hospital, Boston, MA (United States); Chen, Yen-Lin E.; Lu, Hsiao-Ming; Kooy, Hanne [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); MacDonald, Shannon M., E-mail: smacdonald@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States)

    2012-07-01

    Purpose: To report the early outcomes for children with high-risk neuroblastoma treated with proton radiotherapy (RT) and to compare the dose distributions for intensity-modulated photon RT (IMRT), three-dimensional conformal proton RT (3D-CPT), and intensity-modulated proton RT to the postoperative tumor bed. Methods and Materials: All patients with high-risk (International Neuroblastoma Staging System Stage III or IV) neuroblastoma treated between 2005 and 2010 at our institution were included. All patients received induction chemotherapy, surgical resection of residual disease, high-dose chemotherapy with stem cell rescue, and adjuvant 3D-CPT to the primary tumor sites. The patients were followed with clinical examinations, imaging, and laboratory testing every 6 months to monitor disease control and side effects. IMRT, 3D-CPT, and intensity-modulated proton RT plans were generated and compared for a representative case of adjuvant RT to the primary tumor bed followed by a boost. Results: Nine patients were treated with 3D-CPT. The median age at diagnosis was 2 years (range 10 months to 4 years), and all patients had Stage IV disease. All patients had unfavorable histologic characteristics (poorly differentiated histologic features in 8, N-Myc amplification in 6, and 1p/11q chromosomal abnormalities in 4). The median tumor size at diagnosis was 11.4 cm (range 7-16) in maximal dimension. At a median follow-up of 38 months (range 11-70), there were no local failures. Four patients developed distant failure, and, of these, two died of disease. Acute side effects included Grade 1 skin erythema in 5 patients and Grade 2 anorexia in 2 patients. Although comparable target coverage was achieved with all three modalities, proton therapy achieved substantial normal tissue sparing compared with IMRT. Intensity-modulated proton RT allowed additional sparing of the kidneys, lungs, and heart. Conclusions: Preliminary outcomes reveal excellent local control with proton therapy

  20. Light at the end of the tunnel. Chances for the investigation of nonlinear dose-risk relationships

    International Nuclear Information System (INIS)

    Harder, D.

    2008-01-01

    The present contribution aims at illustrating the chances to gain a new comprehension of dose-risk relationships by investigating radiation actions in the promotion and progression phases of carcinogenesis. The mechanisms of the accumulation of somatic mutations and of the immunosurveillance of neoplastic cell clones are clearly consistent with nonlinear dose-risk relationships. Furthermore, a reminder is given of the possibility, existing in the neighbourhood of Chernobyl, of investigating the evolutionary adaption of organisms to chronic low-level radiation exposure. (orig.)

  1. Risk of Developing Second Cancer From Neutron Dose in Proton Therapy as Function of Field Characteristics, Organ, and Patient Age

    International Nuclear Information System (INIS)

    Zacharatou Jarlskog, Christina; Paganetti, Harald

    2008-01-01

    Purpose: To estimate the risk of a second malignancy after treatment of a primary brain cancer using passive scattered proton beam therapy. The focus was on the cancer risk caused by neutrons outside the treatment volume and the dependency on the patient's age. Methods and Materials: Organ-specific neutron-equivalent doses previously calculated for eight different proton therapy brain fields were considered. Organ-specific models were applied to assess the risk of developing solid cancers and leukemia. Results: The main contributors (>80%) to the neutron-induced risk are neutrons generated in the treatment head. Treatment volume can influence the risk by up to a factor of ∼2. Young patients are subject to significantly greater risks than are adult patients because of the geometric differences and age dependency of the risk models. Breast cancer should be the main concern for females. For males, the risks of lung cancer, leukemia, and thyroid cancer were significant for pediatric patients. In contrast, leukemia was the leading risk for an adult. Most lifetime risks were <1% (70-Gy treatment). The only exceptions were breast, thyroid, and lung cancer for females. For female thyroid cancer, the treatment risk can exceed the baseline risk. Conclusion: The risk of developing a second malignancy from neutrons from proton beam therapy of a brain lesion is small (i.e., presumably outweighed by the therapeutic benefit) but not negligible (i.e., potentially greater than the baseline risk). The patient's age at treatment plays a major role

  2. Risk assessment of occupational radiation dose at the teletherapy facility of the Korle-Bu Teaching Hospital, Ghana

    International Nuclear Information System (INIS)

    Gollo, Selasie Richie Valens Kweku

    2016-07-01

    The National centre for Radiotherapy and Nuclear Medicine at the Korle-bu Teaching Hospital in Ghana uses a Theratron Equinox 100 Cobalt-60 teletherapy machine that was commissioned in 2014 with a source activity of 370.4TBq. The prime objective of this research was to estimate the risk and probability of cancer induction to workers and also to evaluate the level of radiation safety at the facility. Data was collected by means of TLDs and personal dose records available between the periods February 2010 and April 2016. The results from 2010-2016 were used to compute the mean annual dose, mean annual collective dose as well as risk assessments using the ICRP 1990 and 2007 recommendations. Ambient dose rate measurements were also done using a Thermo electron survey meter. The Results showed that mean effective dose recorded from TLDs used in this research ranged from 0.08mSv-0.36mSv whiles dose records from 2010-2016 showed mean annual effective doses ranged between 0.23mSv-0.65mSv. Mean annual collective dose was 0.09 mSv. Annual cancer risk estimates also showed that workers probability of developing cancers had a mean value of 2.37 x 10"-"2±7.75 x 10"-"3 whiles risk of passing hereditary traits to offspring born after exposure showed a mean value 3.96 x 10"-"3± 1.29 x 10"-"3 according to the ICRP 1990 recommendations and ICRP 2007 showed that possibility of cancer induction to workers showed a mean value of 2.03 x 10"-"2±1.61 x 10"-"3. Mean annual dose rates did not exceed 14.8mSv/a,5mSv/a and 0.74mSv/a for the treatment room, control console room and the controlled area respectively. This shows that workers at the facility are not likely to exceed the recommended dose limit within a year while working at the facility. Ambient dose rates did not exceed 7.39μSv/hr, 2.80μSv/hr and 0.37μSv/hr for the treatment room, control console room and the controlled area respectively. These values obtained are below the recommended limit of 20μSv/hr. (au)

  3. Radioactive contamination in the Arctic--sources, dose assessment and potential risks

    International Nuclear Information System (INIS)

    Strand, P.; Howard, B.J.; Aarkrog, A.; Balonov, M.; Tsaturov, Y.; Bewers, J.M.; Salo, A.; Sickel, M.; Bergman, R.; Rissanen, K.

    2002-01-01

    Arctic residents, whose diets comprise a large proportion of traditional terrestrial and freshwater foodstuffs, have received the highest radiation exposures to artificial radionuclides in the Arctic. Doses to members of both the average population and selected indigenous population groups in the Arctic depend on the rates of consumption of locally-derived terrestrial and freshwater foodstuffs, including reindeer/caribou meat, freshwater fish, goat cheese, berries, mushrooms and lamb. The vulnerability of arctic populations, especially indigenous peoples, to radiocaesium deposition is much greater than for temperate populations due to the importance of terrestrial, semi-natural exposure pathways where there is high radiocaesium transfer and a long ecological half-life for this radionuclide. In contrast, arctic residents with diets largely comprising marine foodstuffs have received comparatively low radiation exposures because of the lower levels of contamination of marine organisms. Using arctic-specific information, the predicted collective dose is five times higher than that estimated by UNSCEAR for temperate areas. The greatest threats to human health and the environment posed by human and industrial activities in the Arctic are associated with the potential for accidents in the civilian and military nuclear sectors. Of most concern are the consequences of potential accidents in nuclear power plant reactors, during the handling and storage of nuclear weapons, in the decommissioning of nuclear submarines and in the disposal of spent nuclear fuel from vessels. It is important to foster a close association between risk assessment and practical programmes for the purposes of improving monitoring, formulating response strategies and implementing action plans

  4. Risk management or mind control? Possible messages in the report by the working group on the risk management of low-dose exposures

    International Nuclear Information System (INIS)

    Onai, Takayuki; Shirabe, Masashi

    2012-01-01

    Fukushima accident discharged a large amount of radioactive materials to the air and brought about a long-term low-dose radiation exposure risk in contaminated area. In December 2011 the government working group (WG) on the risk management of low-dose radiation exposure issued the report on subjects: (1) health effects from annual radiation exposure of 20 mSv, (2) special consideration necessary for children and pregnant women and (3) proper way communicating citizens on radioactive materials and radiation doses in relation to health risks from low-dose radiation exposure. This article recommended making radiation protection strategies based on discussions among experts, government and citizens in consideration of “uncertainty” of scientific knowledge, and it criticized the WG's report mainly in the following respects. 1) The report mixed evacuation order level and ICRP's reference level in its discussion on “20 mSv”. 2) It was over-optimistic and frequently misleading on health risks of low-dose radiation. For example, it sometimes discussed the risks employing data and knowledge against recommendations of international authorities like UNSCEAR and ICRP. 3) It regarded Fukushima residents’ anxieties and stresses to be controlled as the only source of health risks. This attitude offered a counterpoint to UNSCEAR's deliberate attitude to “radiophobia”. 4) Against the spirit of ICRP Publ.111, only experts of WG made decisions about radiation protection in the absence of stakeholders. As its result, 5) risk communication recommended in the report was not interactive, in fact, based on “deficit model” of science communication. (author)

  5. Risk of Low Dose/Low Dose Rate Ionizing Radiation to Humans Symposium Annual Meeting of the Environmental Mutagen Society: Agenda and Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Veigl, Martina L. [Environmental Mutagen Society (EMS), Reston, VA (United States); Case Western Reserve Univ., Cleveland, OH (United States). Case Comprehensive Cancer Center; Morgan, William F. [Univ. of Maryland, College Park, MD (United States); Schwartz, Jeffrey L. [Univ. of Washington, Seattle, WA (United States)

    2009-11-11

    The low dose symposium thoughtfully addressed controversy of risk from low dose radiation exposure, hormesis and radon therapy. The stem cell symposium cogently considered the role of DNA damage and repair in hematopoietic stem cells underlying aging and malignancy and provocatively presented evidence that stem cells may have distinct morphologies and replicative properties, as well as special roles in cancer initiation. In the epigenetics symposium, studies illustrated the long range interaction of epigenetic mechanisms, the roles of CTCF and BORIS in region/specific regulation of epigenetic processes, the impact of DNA damage on epigenetic processes as well as links between epigenetic mechanisms and early nutrition and bystander effects. This report shows the agenda and abstracts for this symposium.

  6. Radiation dose and subsequent risk for stomach cancer in long-term survivors of cervical cancer

    DEFF Research Database (Denmark)

    Kleinerman, Ruth A; Smith, Susan A; Holowaty, Eric

    2013-01-01

    To assess the dose-response relationship for stomach cancer after radiation therapy for cervical cancer.......To assess the dose-response relationship for stomach cancer after radiation therapy for cervical cancer....

  7. Determination of doses and cancer risk to patients undergoing digital x-ray examinations at the Tamale Teaching Hospital

    International Nuclear Information System (INIS)

    Aweligiba, S.A.

    2015-07-01

    Entrance surface and effective doses as well as cancer risk to patients for three common radiological examinations were estimated at the radiology department of the Tamale Teaching Hospital. The quality control assessment indicated that the digital x-ray equipment used, performed self-consistently in line with acceptable performance criteria. The study included eighty-two (82) adult patients undergoing three x-ray imaging modalities; Chest, Abdomen and Pelvis Examinations. From the study the mean entrance dose to abdomen and pelvis were found to be 0.6 ± 0.2 mGy whiles that of chest was found to be 0.2 ± 0.1 mGy. These were found to be lower than results of studies carried out elsewhere. The effective dose to patient was computed using PCXMC 2.0 software. The results shows an average effective dose of 0.036 mSv, 0.084 mSv and 0.067 mSv for chest, abdomen and pelvis examinations respectively. The risk of radiation induced cancer as a result to entrance surface dose was found to be 5.68 x 10-5 %, 1.58 x 10-4 % and 1.49 x 10-4 % for Chest, Abdomen and Pelvis examinations respectively. The third quartile values of the entrance surface dose were found to be lower than recommended diagnostic reference levels published by NRPB, UK and the IAEA for the examinations under study. (author)

  8. Reference computations of public dose and cancer risk from airborne releases of plutonium. Nuclear safety technical report

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, V.L.

    1993-12-23

    This report presents results of computations of doses and the associated health risks of postulated accidental atmospheric releases from the Rocky Flats Plant (RFP) of one gram of weapons-grade plutonium in a form that is respirable. These computations are intended to be reference computations that can be used to evaluate a variety of accident scenarios by scaling the dose and health risk results presented here according to the amount of plutonium postulated to be released, instead of repeating the computations for each scenario. The MACCS2 code has been used as the basis of these computations. The basis and capabilities of MACCS2 are summarized, the parameters used in the evaluations are discussed, and results are presented for the doses and health risks to the public, both the Maximum Offsite Individual (a maximally exposed individual at or beyond the plant boundaries) and the population within 50 miles of RFP. A number of different weather scenarios are evaluated, including constant weather conditions and observed weather for 1990, 1991, and 1992. The isotopic mix of weapons-grade plutonium will change as it ages, the {sup 241}Pu decaying into {sup 241}Am. The {sup 241}Am reaches a peak concentration after about 72 years. The doses to the bone surface, liver, and whole body will increase slightly but the dose to the lungs will decrease slightly. The overall cancer risk will show almost no change over this period. This change in cancer risk is much smaller than the year-to-year variations in cancer risk due to weather. Finally, x/Q values are also presented for other applications, such as for hazardous chemical releases. These include the x/Q values for the MOI, for a collocated worker at 100 meters downwind of an accident site, and the x/Q value integrated over the population out to 50 miles.

  9. Is Androgen Deprivation Therapy Necessary in All Intermediate-Risk Prostate Cancer Patients Treated in the Dose Escalation Era?

    International Nuclear Information System (INIS)

    Castle, Katherine O.; Hoffman, Karen E.; Levy, Lawrence B.; Lee, Andrew K.; Choi, Seungtaek; Nguyen, Quynh N.; Frank, Steven J.; Pugh, Thomas J.; McGuire, Sean E.; Kuban, Deborah A.

    2013-01-01

    Purpose: The benefit of adding androgen deprivation therapy (ADT) to dose-escalated radiation therapy (RT) for men with intermediate-risk prostate cancer is unclear; therefore, we assessed the impact of adding ADT to dose-escalated RT on freedom from failure (FFF). Methods: Three groups of men treated with intensity modulated RT or 3-dimensional conformal RT (75.6-78 Gy) from 1993-2008 for prostate cancer were categorized as (1) 326 intermediate-risk patients treated with RT alone, (2) 218 intermediate-risk patients treated with RT and ≤6 months of ADT, and (3) 274 low-risk patients treated with definitive RT. Median follow-up was 58 months. Recursive partitioning analysis based on FFF using Gleason score (GS), T stage, and pretreatment PSA concentration was applied to the intermediate-risk patients treated with RT alone. The Kaplan-Meier method was used to estimate 5-year FFF. Results: Based on recursive partitioning analysis, intermediate-risk patients treated with RT alone were divided into 3 prognostic groups: (1) 188 favorable patients: GS 6, ≤T2b or GS 3+4, ≤T1c; (2) 71 marginal patients: GS 3+4, T2a-b; and (3) 68 unfavorable patients: GS 4+3 or T2c disease. Hazard ratios (HR) for recurrence in each group were 1.0, 2.1, and 4.6, respectively. When intermediate-risk patients treated with RT alone were compared to intermediate-risk patients treated with RT and ADT, the greatest benefit from ADT was seen for the unfavorable intermediate-risk patients (FFF, 74% vs 94%, respectively; P=.005). Favorable intermediate-risk patients had no significant benefit from the addition of ADT to RT (FFF, 94% vs 95%, respectively; P=.85), and FFF for favorable intermediate-risk patients treated with RT alone approached that of low-risk patients treated with RT alone (98%). Conclusions: Patients with favorable intermediate-risk prostate cancer did not benefit from the addition of ADT to dose-escalated RT, and their FFF was nearly as good as patients with low-risk disease

  10. Dynamics of rectal balloon implant shrinkage in prostate VMAT. Influence on anorectal dose and late rectal complication risk

    International Nuclear Information System (INIS)

    Vanneste, Ben G.L.; Wijk, Y. van; Lutgens, L.C.; Limbergen, E.J. van; Lambin, P.; Lin, E.N. van; Beek, K. van de; Hoffmann, A.L.

    2018-01-01

    To assess the effect of a shrinking rectal balloon implant (RBI) on the anorectal dose and complication risk during the course of moderately hypofractionated prostate radiotherapy. In 15 patients with localized prostate cancer, an RBI was implanted. A weekly kilovolt cone-beam computed tomography (CBCT) scan was acquired to measure the dynamics of RBI volume and prostate-rectum separation. The absolute anorectal volume encompassed by the 2 Gy equieffective 75 Gy isodose (V 75Gy ) was recalculated as well as the mean anorectal dose. The increase in estimated risk of grade 2-3 late rectal bleeding (LRB) between the start and end of treatment was predicted using nomograms. The observed acute and late toxicities were evaluated. A significant shrinkage of RBI volumes was observed, with an average volume of 70.4% of baseline at the end of the treatment. Although the prostate-rectum separation significantly decreased over time, it remained at least 1 cm. No significant increase in V 75Gy of the anorectum was observed, except in one patient whose RBI had completely deflated in the third week of treatment. No correlation between mean anorectal dose and balloon deflation was found. The increase in predicted LRB risk was not significant, except in the one patient whose RBI completely deflated. The observed toxicities confirmed these findings. Despite significant decrease in RBI volume the high-dose rectal volume and the predicted LRB risk were unaffected due to a persistent spacing between the prostate and the anterior rectal wall. (orig.) [de

  11. Lung dose and lung cancer risk by inhalation of radon daughters

    International Nuclear Information System (INIS)

    Jacobi, W.

    1983-01-01

    The inhalation of short-lived radon daughters constitutes the most important occupational radiation exposure in mines, particularly in uranium mines. Among some groups of miners exposed in the past to relatively high radon levels, an excess lung cancer incidence has been observed. In addition to this occupational hazard, the observed radon levels in domestic houses indicate that the inhalation of short-lived radon daughters seems to be the most important component of the radiation exposure of the population from natural sources. For the quantification and judgment of the radiological impact by inhalation of radon daughters in mines as well as in houses, it is necessary to estimate the relationships between the inhaled activity or potential alpha (α) energy of these radionuclides, the dose to target tissues in the lung, and the possible associated lung cancer (LC) risk. It is the purpose of this paper to give a condensed review of our present knowledge in this field and to indicate the main gaps and uncertainties where future research seems necessary

  12. Long-term biological effects induced by ionizing radiation--implications for dose mediated risk.

    Science.gov (United States)

    Miron, S D; Astărăstoae, V

    2014-01-01

    Ionizing radiations are considered to be risk agents that are responsible for the effects on interaction with living matter. The occurring biological effects are due to various factors such as: dose, type of radiation, exposure time, type of biological tissue, health condition and the age of the person exposed. The mechanisms involved in the direct modifications of nuclear DNA and mitochondrial DNA are reviewed. Classical target theory of energy deposition in the nucleus that causes DNA damages, in particular DNA double-strand breaks and that explanation of the biological consequences of ionizing radiation exposure is a paradigm in radiobiology. Recent experimental evidences have demonstrated the existence of a molecular mechanism that explains the non-targeted effects of ionizing radiation exposure. Among these novel data, genomic instability and a variety of bystander effects are discussed here. Those bystander effects of ionizing radiation are fulfilled by cellular communication systems that give rise to non-targeted effects in the neighboring non irradiated cells. This paper provides also a commentary on the synergistic effects induced by the co-exposures to ionizing radiation and various physical agents such as electromagnetic fields and the co-exposures to ionizing radiation and chemical environmental contaminants such as metals. The biological effects of multiple stressors on genomic instability and bystander effects are also discussed. Moreover, a brief presentation of the methods used to characterize cyto- and genotoxic damages is offered.

  13. Symptomatic acquired zinc deficiency in at-risk premature infants: high dose preventive supplementation is necessary.

    Science.gov (United States)

    Barbarot, Sébastien; Chantier, Emilie; Kuster, Alice; Hello, Muriel; Roze, Jean-Christophe; Blouin, Eric; Stalder, Jean-François

    2010-01-01

    Zinc is a cofactor for several enzymes involved in many metabolisms. Zinc deficiency induces various disorders such as acrodermatitis enteropathica, either inherited or acquired. We report three cases of premature infants (24-31 wks gestational age) with low birthweight (650 to 940 g) and enteropathy, two of whom presented with necrotizing enterocolitis. All infants were fed by total parenteral nutrition. At a chronological age ranging from 73 to 80 days, all infants developed a periorificial dermatitis. Before the onset of the first signs, they had received zinc supplementation ranging from 146% to 195% of the recommended dose (400 microg/kg/day). Increased zinc supplementation over a course of 6-18 days induced a complete resolution of symptoms in all cases. No abnormality in the neurologic examination and no recurrence were observed at the end of the zinc treatment. Low birthweight premature infants with enteropathy on total parenteral nutrition are at risk of developing zinc deficiency. The usual recommended zinc supplementation is probably insufficient for those infants. A delay in the diagnosis of zinc deficiency may lead to severe complications.

  14. Radiation absorbed dose and expected risk in head and neck tissues after thyroid radioiodine therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, A [National Center for Nuclear and Radiation Control, AEA., Cairo (Egypt); Farag, H I [National Cancer instiute, Cairo University, Cairo (Egypt); Saleh, A [Al-hussien Hospital, Al-Azhar University, Cairo (Egypt)

    1997-12-31

    Measurement of absorbed dose in head and neck phantom after applying I-131 therapeutic dose for the treatment of thyroid malignancies was conducted. The measurement were carried out at several sites of phantom using TL dosimeters. The absorbed doses were also measured on the skin of four patients during their administration of I-131 therapeutic doses 1.332 GBq (36 mci) I-131. The measurements were taken over 69 hours exposure at different sites of phantom. The same measurements were carried out on the four patients. At five sites of the patients head and neck, the absorbed dose were measured and compared with that measured on the phantom. The values measured are discussed in the light of the published individual absorbed doses in the organs by ICRP tables. High absorbed doses were absorbed in the different sites of the head and neck during the I-131 therapy (0.14-9.68 mGy/mCi). 3 figs., 2 tabs.

  15. SU-E-J-10: Imaging Dose and Cancer Risk in Image-Guided Radiotherapy of Cancers

    International Nuclear Information System (INIS)

    Zhou, L; Bai, S; Zhang, Y; Deng, J

    2015-01-01

    Purpose: To systematically evaluate imaging doses and cancer risks to organs-at-risk as a Result of cumulative doses from various radiological imaging procedures in image-guided radiotherapy (IGRT) in a large cohort of cancer patients. Methods: With IRB approval, imaging procedures (computed tomography, kilo-voltage portal imaging, megavoltage portal imaging and kilo-voltage cone-beam computed tomography) of 4832 cancer patients treated during 4.5 years were collected with their gender, age and circumference. Correlations between patient’s circumference and Monte Carlo simulated-organ dose were applied to estimate organ doses while the cancer risks were reported as 1+ERR using BEIR VII models. Results: 80 cGy or more doses were deposited to brain, lungs and RBM in 273 patients (maximum 136, 278 and 267 cGy, respectively), due largely to repetitive imaging procedures and non-personalized imaging settings. Regardless of gender, relative cancer risk estimates for brain, lungs, and RBM were 3.4 (n = 55), 2.6 (n = 49), 1.8 (n = 25) for age group of 0–19; 1.2 (n = 87), 1.4 (n = 98), 1.3 (n = 51) for age group of 20–39; 1.0 (n = 457), 1.1 (n = 880), 1.8 (n=360) for age group of 40–59; 1.0 (n = 646), 1.1 (n = 1400), 2.3 (n = 716) for age group of 60–79 and 1.0 (n = 108),1.1 (n = 305),1.6 (n = 147) for age group of 80–99. Conclusion: The cumulative imaging doses and associated cancer risks from multi-imaging procedures were patient-specific and site-dependent, with up to 2.7 Gy imaging dose deposited to critical structures in some pediatric patients. The associated cancer risks in brain and lungs for children of age 0 to 19 were 2–3 times larger than those for adults. This study indicated a pressing need for personalized imaging protocol to maximize its clinical benefits while reducing associated cancer risks. Sichuan University Scholarship

  16. What physicians think about the need for informed consent for communicating the risk of cancer from low-dose radiation

    International Nuclear Information System (INIS)

    Karsli, Tijen; Kalra, Mannudeep K.; Self, Julie L.; Rosenfeld, Jason Anders; Butler, Susan; Simoneaux, Stephen

    2009-01-01

    The National Institute of Environmental Health Sciences, a subsidiary of the Food and Drug Administration, has declared that X-ray radiation at low doses is a human carcinogen. The purpose of our study was to determine if informed consent should be obtained for communicating the risk of radiation-induced cancer from radiation-based imaging. Institutional review board approval was obtained for the prospective survey of 456 physicians affiliated with three tertiary hospitals by means of a written questionnaire. Physicians were asked to state their subspecialty, number of years in practice, frequency of referral for CT scanning, level of awareness about the risk of radiation-induced cancer associated with CT, knowledge of whether such information is provided to patients undergoing CT, and opinions about the need for obtaining informed consent as well as who should provide information about the radiation-induced cancer risk to patients. Physicians were also asked to specify their preference among different formats of informed consent for communicating the potential risk of radiation-induced cancer. Statistical analyses were performed using the chi-squared test. Most physicians stated that informed consent should be obtained from patients undergoing radiation-based imaging (71.3%, 325/456) and the radiology department should provide information about the risk of radiation-induced cancer to these patients (54.6%, 249/456). The informed consent format that most physicians agreed with included modifications to the National Institute of Environmental Health Services report on cancer risk from low-dose radiation (20.2%, 92/456) or included information on the risk of cancer from background radiation compared to that from low-dose radiation (39.5%, 180/456). Most physicians do not know if patients are informed about cancer risk from radiation-based imaging in their institutions. However, they believe that informed consent for communicating the risk of radiation-induced cancer

  17. Radiation dose dependent risk of liver cancer mortality in the German uranium miners cohort 1946–2003

    International Nuclear Information System (INIS)

    Dufey, F; Walsh, L; Sogl, M; Tschense, A; Schnelzer, M; Kreuzer, M

    2013-01-01

    An increased risk of mortality from primary liver cancers among uranium miners has been observed in various studies. An analysis of the data from a German uranium miner cohort (the ‘Wismut cohort’) was used to assess the relationship with ionising radiation. To that end the absorbed organ dose due to high and low linear energy transfer radiation was calculated for 58 987 miners with complete information on radiation exposure from a detailed job–exposure matrix. 159 deaths from liver cancer were observed in the follow-up period from 1946 to 2003. Relative risk models with either linear or categorical dependence on high and low linear energy transfer radiation liver doses were fitted by Poisson regression, stratified on age and calendar year. The linear trend of excess relative risk in a model with both low and high linear transfer radiation is −0.8 (95% confidence interval (CI): −3.7, 2.1) Gy −1 and 48.3 (95% CI: −32.0, 128.6) Gy −1 for low and high linear energy transfer radiation, respectively, and thus not statistically significant for either dose. The increase of excess relative risk with equivalent liver dose is 0.57 (95% CI: −0.69, 1.82) Sv −1 . Adjustment for arsenic only had a negligible effect on the radiation risk. In conclusion, there is only weak evidence for an increase of liver cancer mortality with increasing radiation dose in the German uranium miners cohort considered. However, both a lack of statistical power and potential misclassification of primary liver cancer are issues. (paper)

  18. CALDoseX-a software tool for the assessment of organ and tissue absorbed doses, effective dose and cancer risks in diagnostic radiology

    International Nuclear Information System (INIS)

    Kramer, R; Khoury, H J; Vieira, J W

    2008-01-01

    CALDose X is a software tool that provides the possibility of calculating incident air kerma (INAK) and entrance surface air kerma (ESAK), two important quantities used in x-ray diagnosis, based on the output of the x-ray equipment. Additionally, the software uses conversion coefficients (CCs) to assess the absorbed dose to organs and tissues of the human body, the effective dose as well as the patient's cancer risk for radiographic examinations. The CCs, ratios between organ or tissue absorbed doses and measurable quantities, have been calculated with the FAX06 and the MAX06 phantoms for 34 projections of 10 commonly performed x-ray examinations, for 40 combinations of tube potential and filtration ranging from 50 to 120 kVcp and from 2.0 to 5.0 mm aluminum, respectively, for various field positions, for 29 selected organs and tissues and simultaneously for the measurable quantities, INAK, ESAK and kerma area product (KAP). Based on the x-ray irradiation parameters defined by the user, CALDose X shows images of the phantom together with the position of the x-ray beam. By using true to nature voxel phantoms, CALDose X improves earlier software tools, which were mostly based on mathematical MIRD5-type phantoms, by using a less representative human anatomy.

  19. Job related mortality risks of Hanford workers and their relation to cancer effects of measured doses of external radiation

    International Nuclear Information System (INIS)

    Kneale, G.W.; Mancuso, T.F.; Stewart, A.M.

    1984-01-01

    A continuation of the series by Mancuso, Stewart, and Kneale (MSK) on studies of cancer risks for radiation workers at Hanford is presented. It concentrates on the statistical problems posed by the need to estimate and control for job related mortality risks when there are several changes of occupation and no certainty about how different occupations are related to two socioeconomic factors which have strong health associations-namely, education and income. The final conclusion is that for tissues which are sensitive to cancer induced by radiation there is a risk of cancer for Hanford exposures whose dose response is curvilinear with long latency and increasing effect with increasing exposure age. (author)

  20. Dose to the Contralateral Breast From Radiotherapy and Risk of Second Primary Breast Cancer in the WECARE Study

    International Nuclear Information System (INIS)

    Stovall, Marilyn; Smith, Susan A.; Langholz, Bryan M.; Boice, John D.; Shore, Roy E.; Andersson, Michael; Buchholz, Thomas A.; Capanu, Marinela; Bernstein, Leslie; Lynch, Charles F.; Malone, Kathleen E.; Anton-Culver, Hoda; Haile, Robert W.; Rosenstein, Barry S.

    2008-01-01

    Purpose: To quantify the risk of second primary breast cancer in the contralateral breast (CB) after radiotherapy (RT) for first breast cancer. Methods and Materials: The study population included participants in the Women's Environmental, Cancer, and Radiation Epidemiology study: 708 cases (women with asynchronous bilateral breast cancer) and 1399 controls (women with unilateral breast cancer) counter-matched on radiation treatment. Participants were 1.0 Gy of absorbed dose to the specific quadrant of the CB had a 2.5-fold greater risk for CB cancer than unexposed women (RR = 2.5, 95% CI 1.4-4.5). No excess risk was observed in women >40 years of age. Women 5 years had a RR of 3.0 (95% CI 1.1-8.1), and the dose response was significant (excess RR per Gy of 1.0, 95% CI 0.1-3.0). Conclusions: Women 1.0 Gy to the CB had an elevated, long-term risk of developing a second primary CB cancer. The risk is inversely related to age at exposure and is dose dependent

  1. Radiation-Induced Noncancer Risks in Interventional Cardiology: Optimisation of Procedures and Staff and Patient Dose Reduction

    Science.gov (United States)

    Khairuddin Md Yusof, Ahmad

    2013-01-01

    Concerns about ionizing radiation during interventional cardiology have been increased in recent years as a result of rapid growth in interventional procedure volumes and the high radiation doses associated with some procedures. Noncancer radiation risks to cardiologists and medical staff in terms of radiation-induced cataracts and skin injuries for patients appear clear potential consequences of interventional cardiology procedures, while radiation-induced potential risk of developing cardiovascular effects remains less clear. This paper provides an overview of the evidence-based reviews of concerns about noncancer risks of radiation exposure in interventional cardiology. Strategies commonly undertaken to reduce radiation doses to both medical staff and patients during interventional cardiology procedures are discussed; optimisation of interventional cardiology procedures is highlighted. PMID:24027768

  2. Natural radiation dose due to 210Po and associated risk to certain fishes of Kudankulam Waters, Gulf of Mannar

    International Nuclear Information System (INIS)

    Praveen Pole, R.P.; Godwin Wesley, S.; Vijayakumar, B.

    2014-01-01

    With increasing emphasis on environmental protection, concern has switched over from the earlier target human being to non-human species regarding possible radiation risk. Alpha-emitter 210 Po (t 1/2 = 138.4 d) is the most important radionuclide, considering it as a potential natural source of internal radiation dose to marine organisms. Fishes are known to accumulate 210 Po to a large extent through food chains and certain marine fishes are potential bioindicators as they bioaccumulate the target radionuclide from surrounding waters. Hence it is imperative to assess the level of 210 Po and the radiological risk (risk quotient) due to the radiation dose received by different fish species collected from the coastal areas around the nuclear installation at Kudankulam

  3. Risk assessment from heterogeneous energy deposition in tissue, the problem of effects from low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Feinendegen, L.E.; Booz, J.

    1992-01-01

    Low doses of ionizing radiation from external or internal sources cause heterogeneous distribution of energy deposition events in the exposed biological system. With the cell being the individual element of the tissue system, the fraction of cells hit, the dose received by the hit, and the biological response of the cell to the dose received eventually determine the effect in tissue. The hit cell may experience detriment, such as change in its DNA leading to a malignant transformation, or it may derive benefit in terms of an adaptive response such as a temporary improvement of DNA repair or temporary prevention of effects from intracellular radicals through enhanced radical detoxification. These responses are protective also to toxic substances that are generated during normal metabolism. Within a multicellular system the probability of detriment must be weighed against the probability of benefit through adaptive responses with protection against various toxic agents including those produced by normal metabolism. Because irradiation can principally induce both, detriment and adaptive responses, one type of affected cells may not be simply summed up at the expense of cells with other types of effects, in assessing risk to tissue. An inventory of various types of effects in the blood-forming system of mammals, even with large ranges of uncertainty, uncovers the possibility of benefit to the system from exposure to low doses of low-LET radiation. This experimental approach may complement epidemiological data on individuals exposed to low doses of ionizing radiation and may lead to a more rational appraisal of risk

  4. Dose-response meta-analysis on coffee, tea and caffeine consumption with risk of Parkinson's disease.

    Science.gov (United States)

    Qi, Hui; Li, Shixue

    2014-04-01

    A dose-response meta-analysis was carried out between Parkinson's disease (PD) risk, and coffee, tea and caffeine consumption. A comprehensive search was carried out to identify eligible studies. The fixed or random effect model was used based on heterogeneity test. The dose-response relationship was assessed by restricted cubic spline. A total of 13 articles involving 901 764 participants for coffee, eight articles involving 344 895 participants for tea and seven articles involving 492 724 participants for caffeine were included. A non-linear relationship was found between coffee consumption and PD risk overall, and the strength of protection reached the maximum at approximately 3 cups/day (smoking-adjusted relative risk: 0.72, 95% confidence interval 0.65-0.81). A linear relationship was found between tea and caffeine consumption, and PD risk overall, and the smoking-adjusted risk of PD decreased by 26% and 17% for every two cups/day and 200 mg/day increments, respectively. The association of coffee and tea consumption with PD risk was stronger for men than that for women, and the association of caffeine consumption with PD risk was stronger for ever users of hormones than that for never users of hormones among postmenopausal women. The aforementioned associations were weaker for USA relative to Europe or Asia. A linear dose-relationship for decreased PD risk with tea and caffeine consumption was found, whereas the strength of protection reached a maximum at approximately 3 cups/day for coffee consumption overall. Further studies are required to confirm the findings. © 2013 Japan Geriatrics Society.

  5. Job-related mortality risks of Hanford workers and their relation to cancer effects of measured doses of external radiation

    International Nuclear Information System (INIS)

    Kneale, G.W.; Mancuso, T.F.; Stewart, A.M.

    1983-01-01

    If we exclude all persons who were classified as clerical workers we find that over 40% of the Hanford workers had either professional or technical qualifications (professional workers). The ratio of professional to manual workers was equally high for safe and dangerous occupations but during the period 1944-77 professional workers who were doing the most dangerous work had too many deaths by comparison with other persons with similar qualifications, and manual workers doing equally dangerous work had too few deaths by comparison with other manual workers. In practice, this means that in any analysis of dose-related cancer risks of Hanford workers it is essential to control for job-related mortality risks as well as all the usual factors such as sex, dates of birth and hire and duration of employment. The results of including all these factors in a cohort analysis of Hanford data by the method of regression models in life tables are described and also the reasons why it was concluded that the risk per unit dose is increased at low dose levels (i.e. the dose-response curve is curvilinear downwards). (author)

  6. Radiology Residents' Awareness about Ionizing Radiation Doses in Imaging Studies and Their Cancer Risk during Radiological Examinations

    Energy Technology Data Exchange (ETDEWEB)

    Goekce, Senem Divrik [I. Ikad Community Health Center, Health Directorate, Samsun (Turkmenistan); Gekce, Erkan [Samsun Maternity and Women' s Disease and Pediatrics Hospital, Samsun (Turkmenistan); Coskun, Melek [Faculty of Medicine, Ondokuz May' s University, Samsun (Turkmenistan)

    2012-03-15

    Imaging methods that use ionizing radiation have been more frequent in various medical fields with advances in imaging technology. The aim of our study was to make residents be aware of the radiation dose they are subjected to when they conduct radiological imaging methods, and of cancer risk. A total of 364 residents participated in this descriptive study which was conducted during the period between October, 2008 and January, 2009. The questionnaires were completed under strict control on a one-to-one basis from each department. A X{sup 2}-test was used for the evaluation of data obtained. Only 7% of residents correctly answered to the question about the ionizing radiation dose of a posteroanterior (PA) chest X-ray. The question asking about the equivalent number of PA chest X-rays to the ionizing dose of a brain CT was answered correctly by 24% of residents; the same question regarding abdominal CT was answered correctly by 16% of residents, thorax CT by 16%, thyroid scintigraphy by 15%, intravenous pyelography by 9%, and lumbar spine radiography by 2%. The risk of developing a cancer throughout lifetime by a brain and abdominal CT were 33% and 28%, respectively. Radiologic residents should have updated knowledge about radiation dose content and attendant cancer risks of various radiological imaging methods during both basic medical training period and following practice period.

  7. Evaluation of doses and risks from different decontamination and decommissioning strategies using the PRESTO-II methodology

    International Nuclear Information System (INIS)

    Fields, D.E.

    1986-01-01

    The PRESTO-II methodology may be applied to evaluate doses and health risks from a variety of decontamination and decommissioning activities. This methodology has been implemented in the form of a computer code that has been applied to several sites, and that has been extensively documented. Radionuclide inventories are specified as separate contamination sources either present on the ground surface, covered by non-radioactive soils but lying above the water table, suspended in the atmosphere, or dissolved in surface waters. Hydrologic transport mechanisms considered in the PRESTO-II methodology include chemical exchange, ponding and overflow, surface water transport, groundwater transport, and pumping contaminated groundwater from wells. Varied scenarios of water usage are treated. Atmospheric inputs are based on both resuspension factor and resuspension rate approaches, with inhalation and immersion doses based on a Gaussian plume transport calculation. Site activities that are considered include land clearing, farming, and residing on the site. Exposure and dose calculations are derived from the US Nuclear Regulatory Commission Reg. Guide 1.109 approach, while risk calculations use a life-table approach developed for the US Environmental Protection Agency (EPA). Internal dose conversion factors are taken from ICRP 26 and 30, while risk conversion factors are values suggested by EPA. 19 refs., 2 figs., 1 tab

  8. Radiology Residents' Awareness about Ionizing Radiation Doses in Imaging Studies and Their Cancer Risk during Radiological Examinations

    Science.gov (United States)

    Divrik Gökçe, Senem; Coşkun, Melek

    2012-01-01

    Objective Imaging methods that use ionizing radiation have been more frequent in various medical fields with advances in imaging technology. The aim of our study was to make residents be aware of the radiation dose they are subjected to when they conduct radiological imaging methods, and of cancer risk. Materials and Methods A total of 364 residents participated in this descriptive study which was conducted during the period between October, 2008 and January, 2009. The questionnaires were completed under strict control on a one-to-one basis from each department. A χ2-test was used for the evaluation of data obtained. Results Only 7% of residents correctly answered to the question about the ionizing radiation dose of a posteroanterior (PA) chest X-ray. The question asking about the equivalent number of PA chest X-rays to the ionizing dose of a brain CT was answered correctly by 24% of residents; the same question regarding abdominal CT was answered correctly by 16% of residents, thorax CT by 16%, thyroid scintigraphy by 15%, intravenous pyelography by 9%, and lumbar spine radiography by 2%. The risk of developing a cancer throughout lifetime by a brain and abdominal CT were 33% and 28%, respectively. Conclusion Radiologic residents should have updated knowledge about radiation dose content and attendant cancer risks of various radiological imaging methods during both basic medical training period and following practice period. PMID:22438688

  9. Radiology Residents' Awareness about Ionizing Radiation Doses in Imaging Studies and Their Cancer Risk during Radiological Examinations

    International Nuclear Information System (INIS)

    Goekce, Senem Divrik; Gekce, Erkan; Coskun, Melek

    2012-01-01

    Imaging methods that use ionizing radiation have been more frequent in various medical fields with advances in imaging technology. The aim of our study was to make residents be aware of the radiation dose they are subjected to when they conduct radiological imaging methods, and of cancer risk. A total of 364 residents participated in this descriptive study which was conducted during the period between October, 2008 and January, 2009. The questionnaires were completed under strict control on a one-to-one basis from each department. A X 2 -test was used for the evaluation of data obtained. Only 7% of residents correctly answered to the question about the ionizing radiation dose of a posteroanterior (PA) chest X-ray. The question asking about the equivalent number of PA chest X-rays to the ionizing dose of a brain CT was answered correctly by 24% of residents; the same question regarding abdominal CT was answered correctly by 16% of residents, thorax CT by 16%, thyroid scintigraphy by 15%, intravenous pyelography by 9%, and lumbar spine radiography by 2%. The risk of developing a cancer throughout lifetime by a brain and abdominal CT were 33% and 28%, respectively. Radiologic residents should have updated knowledge about radiation dose content and attendant cancer risks of various radiological imaging methods during both basic medical training period and following practice period.

  10. Radiation induced bystander effects: mechanisms and implication for low dose radiation risk assessment

    International Nuclear Information System (INIS)

    Hei, T.L.; Randers-Pehrson, G.; Zhou, H.

    2003-01-01

    Using a precision microbeam to target an exact fraction of cells in a population and irradiated their nuclei with exactly one alpha particle each, we found that the frequencies of induced mutations and chromosomal changes in populations where some known fractions of nuclei were hit are consistent with non-hit cells contributing significantly to the response. In fact, irradiation of 10% of a mammalian cell population with a single alpha particle per cell results in a mutant yield similar to that observed when all of the cells in the population are irradiated. Although the bystander observations have been well established, the underlying mechanism(s) remain largely unknown. There are indications that multiple pathways are involved in the bystander phenomenon and different cell types respond differently to the bystander signaling. In confluent monolayers, there is evident that gap junctional communication is crucial in mediating the bystander effect whereas reactive oxygen and reactive nitrogen species have been implicated as the mediating molecules in sub-confluent cultures. Although p53 is not necessary for the expression of bystander effect, there is evident that repair deficient cells may express a higher bystander response. Using cDNA microarrays, a number of cellular signaling genes have been shown to be differentially expressed among bystander cells. The functional roles of these genes in the bystander effect will be discussed. The bystander observations imply that the relevant target for various radiobiological endpoints is larger than an individual cell and suggest a need to reconsider the validity of the linear extrapolation in making risk estimate for low dose radiation exposure. (Work supported by NIH grants CA 49062 and CA-RR11623)

  11. Stereotactic body radiation therapy for low- and low-intermediate risk prostate cancer: Is there a dose effect?

    Directory of Open Access Journals (Sweden)

    Alan Jay Katz

    2011-12-01

    Full Text Available This study examines the efficacy and toxicity of two stereotactic body radiation therapy (SBRT dose regimens for treatment of early prostate cancer. Forty-one patients treated with 35 Gy were matched with 41 patients treated with 36.25 Gy. Both patient groups received SBRT in 5 fractions over 5 consecutive days using the CyberKnife. Each group had 37 low-risk patients and 4 intermediate-risk patients. No statistically significant differences were present for age, prostate volume, PSA, Gleason score, stage, or risk between the groups. The dose was prescribed to the 83-87% isodose line to cover the prostate and a 5-mm margin all around, except 3 mm posteriorly. The overall median follow-up is 51 months (range, 45-58 months with a median 54 months and 48 months follow-up for the 35-Gy and 36.25-Gy dose groups, respectively. One biochemical failure occurred in each group yielding a 97.5% freedom from biochemical failure. The PSA response has been favorable for all patients with a mean PSA of 0.1 ng/ml at 4-years. Overall toxicity has been mild with 5% late grade 2 rectal toxicity in both dose groups. Late grade 1 urinary toxicity was equivalent between groups; grade 2 urinary toxicity was 5% (2/41 patients and 10% (4/41 patients in the 35-Gy and 36.25-Gy dose groups (p = 0.6969, respectively. Overall, the highly favorable PSA response, limited biochemical failures, limited toxicity, and limited impact on quality of life in these low- to low-intermediate-risk patients are supportive of excellent long-term results for CyberKnife delivered SBRT.

  12. Low-Dose Aspirin Reduces Breast Cancer Risk in Women with Diabetes: A Nationwide Retrospective Cohort Study in Taiwan.

    Science.gov (United States)

    Yang, Yi-Sun; Kornelius, Edy; Chiou, Jeng-Yuan; Lai, Yung-Rung; Lo, Shih-Chang; Peng, Chiung-Huei; Huang, Chien-Ning

    2017-12-01

    Low-dose aspirin is commonly used for preventing cardiovascular disease in people with diabetes, but its association with cancer remains controversial. This study used a nationwide population-based reimbursement database to investigate the relationship between low-dose aspirin use and breast cancer incidence in women with diabetes. This retrospective cohort study was conducted using data retrieved from the National Health Insurance Research Database in Taiwan from January 1, 1998 to December 31, 2011. Women diagnosed as having diabetes with low-dose aspirin use (75-165 mg daily) were identified as the study population, whereas those without low-dose aspirin use were selected as the comparison group. We analyzed 148,739 patients with diabetes. Their mean age (standard deviation) was 63.3 (12.8) years. A total of 27,378 patients were taking aspirin. Overall, the use of aspirin in patients with diabetes reduced the risk of breast cancer by 18% (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.71-0.94) after adjustment for potential confounders, namely age and comorbidities. Specifically, a cumulative dose of aspirin exceeding 88,900 mg was observed to reduce the risk of breast cancer by 47% (HR, 0.53, 95% CI, 0.43-0.67); however, low (aspirin did not reduce the risk of breast cancer. Our findings suggest that a cumulative aspirin dosage of more than 88,900 mg daily was associated with a reduced risk of breast cancer in women with diabetes. However, additional studies are necessary to confirm these findings.

  13. A snapshot of patients' awareness of radiation dose and risks associated with medical imaging examinations at an Australian radiology clinic.

    Science.gov (United States)

    Singh, N; Mohacsy, A; Connell, D A; Schneider, M E

    2017-05-01

    Cumulative radiation exposure is linked to increasing the lifetime attributable risk of cancer. To avoid unnecessary radiation exposure and facilitate shared decision making, patients should be aware of these issues. This paper examines patients' awareness of radiation dose and risks associated with medical imaging examinations. Consecutive patients attending a private radiology clinic over a nine week period in 2014 in Metropolitan Melbourne were surveyed while waiting to undergo an imaging examination. Patients who were under 18 years of age, did not speak English and/or were referred for interventional imaging procedures were excluded from participation. Survey questions addressed patients' awareness of radiation dose associated with various imaging modalities' and patients' experience and preferences regarding communication of information about radiation. Data was analysed using SPSS (Ver 20.1). A total of 242 surveys were completed. Most participants were male (143/239, 59.8%) and aged between 33 and 52 years (109/242, 45%). Over half of participants were not concerned about radiation from medical imaging (130/238, 54.6%). Only a third of participants (80/234, 34.2%) correctly reported that CT has a higher radiation dose than X-ray. Very few participants correctly identified mammography, DEXA, PET and PET/CT as radiation emitting examinations. The majority of participants (202/236, 85.6%) indicated that they were not informed about radiation dose and risks by their referring doctor in advance. This paper provides information relevant to a single private radiology clinic in Australia. Nevertheless, our results have shown that patients presenting for medical imaging have little awareness of radiation dose and risks associated with these examinations and received little information by their referring physicians or staff at the radiology clinic. Copyright © 2016 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

  14. Risk group dependence of dose-response for biopsy outcome after three-dimensional conformal radiation therapy of prostate cancer

    International Nuclear Information System (INIS)

    Levegruen, Sabine; Jackson, Andrew; Zelefsky, Michael J.; Venkatraman, Ennapadam S.; Skwarchuk, Mark W.; Schlegel, Wolfgang; Fuks, Zvi; Leibel, Steven A.; Ling, C. Clifton

    2002-01-01

    Background and purpose: We fit phenomenological tumor control probability (TCP) models to biopsy outcome after three-dimensional conformal radiation therapy (3D-CRT) of prostate cancer patients to quantify the local dose-response of prostate cancer. Materials and methods: We analyzed the outcome after photon beam 3D-CRT of 103 patients with stage T1c-T3 prostate cancer treated at Memorial Sloan-Kettering Cancer Center (MSKCC) (prescribed target doses between 64.8 and 81 Gy) who had a prostate biopsy performed ≥2.5 years after end of treatment. A univariate logistic regression model based on D mean (mean dose in the planning target volume of each patient) was fit to the whole data set and separately to subgroups characterized by low and high values of tumor-related prognostic factors T-stage ( 6), and pre-treatment prostate-specific antigen (PSA) (≤10 ng/ml vs. >10 ng/ml). In addition, we evaluated five different classifications of the patients into three risk groups, based on all possible combinations of two or three prognostic factors, and fit bivariate logistic regression models with D mean and the risk group category to all patients. Dose-response curves were characterized by TCD 50 , the dose to control 50% of the tumors, and γ 50 , the normalized slope of the dose-response curve at TCD 50 . Results: D mean correlates significantly with biopsy outcome in all patient subgroups and larger values of TCD 50 are observed for patients with unfavorable compared to favorable prognostic factors. For example, TCD 50 for high T-stage patients is 7 Gy higher than for low T-stage patients. For all evaluated risk group definitions, D mean and the risk group category are independent predictors of biopsy outcome in bivariate analysis. The fit values of TCD 50 show a clear separation of 9-10.6 Gy between low and high risk patients. The corresponding dose-response curves are steeper (γ 50 =3.4-5.2) than those obtained when all patients are analyzed together (γ 50 =2

  15. Physics must join with biology in better assessing risk from low-dose irradiation

    International Nuclear Information System (INIS)

    Feinendegen, L. E.; Neumann, R. D.

    2005-01-01

    This review summarises the complex response of mammalian cells and tissues to low doses of ionising radiation. This thesis encompasses induction of DNA damage, and adaptive protection against both renewed damage and against propagation of damage from the basic level of biological organisation to the clinical expression of detriment. The induction of DNA damage at low radiation doses apparently is proportional to absorbed dose at the physical/chemical level. However, any propagation of such damage to higher levels of biological organisation inherently follows a sigmoid function. Moreover, low-dose-induced inhibition of damage propagation is not linear, but instead follows a dose-effect function typical for adaptive protection, after an initial rapid rise it disappears at doses higher than ∼0.1-0.2 Gy to cells. The particular biological response duality at low radiation doses precludes the validity of the linear-no-threshold hypothesis in the attempt to relate absorbed dose to cancer. In fact, theory and observation support not only a lower cancer incidence than expected from the linear-no-threshold hypothesis, but also a reduction of spontaneously occurring cancer, a hormetic response, in the healthy individual. (authors)

  16. Health risk assessment of doses to patients\\' eyes from dental X-ray ...

    African Journals Online (AJOL)

    The skin entry dose to patients\\' eyes during dental x-ray examination was carried out on one hundred and ten patients comprising infants and adult of both sexes. The dose measurements was performed at Alpha dental centre, Ibadan, using Lithium fluoride thermoluminiscent dosimeters (TLD). The results of the study ...

  17. Low-Dose Aspirin Discontinuation and Risk of Cardiovascular Events: A Swedish Nationwide, Population-Based Cohort Study.

    Science.gov (United States)

    Sundström, Johan; Hedberg, Jakob; Thuresson, Marcus; Aarskog, Pernilla; Johannesen, Kasper Munk; Oldgren, Jonas

    2017-09-26

    There are increasing concerns about risks associated with aspirin discontinuation in the absence of major surgery or bleeding. We investigated whether long-term low-dose aspirin discontinuation and treatment gaps increase the risk of cardiovascular events. We performed a cohort study of 601 527 users of low-dose aspirin for primary or secondary prevention in the Swedish prescription register between 2005 and 2009 who were >40 years of age, were free from previous cancer, and had ≥80% adherence during the first observed year of treatment. Cardiovascular events were identified with the Swedish inpatient and cause-of-death registers. The first 3 months after a major bleeding or surgical procedure were excluded from the time at risk. During a median of 3.0 years of follow-up, 62 690 cardiovascular events occurred. Patients who discontinued aspirin had a higher rate of cardiovascular events than those who continued (multivariable-adjusted hazard ratio, 1.37; 95% confidence interval, 1.34-1.41), corresponding to an additional cardiovascular event observed per year in 1 of every 74 patients who discontinue aspirin. The risk increased shortly after discontinuation and did not appear to diminish over time. In long-term users, discontinuation of low-dose aspirin in the absence of major surgery or bleeding was associated with a >30% increased risk of cardiovascular events. Adherence to low-dose aspirin treatment in the absence of major surgery or bleeding is likely an important treatment goal. © 2017 American Heart Association, Inc.

  18. Risk of a Second Kidney Carcinoma Following Childhood Cancer: Role of Chemotherapy and Radiation Dose to Kidneys.

    Science.gov (United States)

    de Vathaire, Florent; Scwhartz, Boris; El-Fayech, Chiraz; Allodji, Rodrigue Sètchéou; Escudier, Bernard; Hawkins, Mike; Diallo, Ibrahima; Haddy, Nadia

    2015-11-01

    Kidney carcinoma is a rare second malignancy following childhood cancer. We sought to quantify risk and assess risk factors for kidney carcinoma following treatment for childhood cancer. We evaluated a cohort of 4,350 patients who were 5-year cancer survivors and had been treated for cancer as children in France and the United Kingdom. Patients were treated between 1943 and 1985, and were followed for an average of 27 years. Radiation dose to the kidneys during treatment was estimated with dedicated software, regardless of the site of childhood cancer. Kidney carcinoma developed in 13 patients. The cumulative incidence of kidney carcinoma was 0.62% (95% CI 0.27%-1.45%) at 40 years after diagnosis, which was 13.3-fold higher (95% CI 7.1-22.3) than in the general population. The absolute excess risk strongly increased with longer duration of followup (p kidney carcinoma was 5.7-fold higher (95% CI 1.4-14.7) if radiotherapy was not performed or less than 1 Gy had been absorbed by the kidney but 66.3-fold higher (95% CI 23.8-142.5) if the radiation dose to the kidneys was 10 to 19 Gy and 14.5-fold higher (95% CI 0.8-63.9) for larger radiation doses to the kidney. Treatment with chemotherapy increased the risk of kidney carcinoma (RR 5.1, 95% CI 1.1-22.7) but we were unable to identify a specific drug or drug category responsible for this effect. Moderate radiation dose to the kidneys during childhood cancer treatment increases the risk of a second kidney carcinoma. This incidence will be further increased when childhood cancer survivors reach old age. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  19. A meta-analysis on dose-response relationship between night shift work and the risk of breast cancer.

    Science.gov (United States)

    Wang, F; Yeung, K L; Chan, W C; Kwok, C C H; Leung, S L; Wu, C; Chan, E Y Y; Yu, I T S; Yang, X R; Tse, L A

    2013-11-01

    This study aimed to conduct a systematic review to sum up evidence of the associations between different aspects of night shift work and female breast cancer using a dose-response meta-analysis approach. We systematicly searched all cohort and case-control studies published in English on MEDLINE, Embase, PSYCInfo, APC Journal Club and Global Health, from January 1971 to May 2013. We extracted effect measures (relative risk, RR; odd ratio, OR; or hazard ratio, HR) from individual studies to generate pooled results using meta-analysis approaches. A log-linear dose-response regression model was used to evaluate the relationship between various indicators of exposure to night shift work and breast cancer risk. Downs and Black scale was applied to assess the methodological quality of included studies. Ten studies were included in the meta-analysis. A pooled adjusted relative risk for the association between 'ever exposed to night shift work' and breast cancer was 1.19 [95% confidence interval (CI) 1.05-1.35]. Further meta-analyses on dose-response relationship showed that every 5-year increase of exposure to night shift work would correspondingly enhance the risk of breast cancer of the female by 3% (pooled RR = 1.03, 95% CI 1.01-1.05; Pheterogeneity night shifts would result in a 13% (RR = 1.13, 95% CI 1.07-1.21; Pheterogeneity = 0.06) increase in breast cancer risk. This systematic review updated the evidence that a positive dose-response relationship is likely to present for breast cancer with increasing years of employment and cumulative shifts involved in the work.

  20. Risk of venous thromboembolism from use of oral contraceptives containing different progestogens and oestrogen doses: Danish cohort study, 2001-9

    DEFF Research Database (Denmark)

    Lidegaard, Øjvind; Nielsen, Lars Hougaard; Skovlund, Charlotte Wessel

    2011-01-01

    To assess the risk of venous thromboembolism from use of combined oral contraceptives according to progestogen type and oestrogen dose.......To assess the risk of venous thromboembolism from use of combined oral contraceptives according to progestogen type and oestrogen dose....

  1. Low-dose CT screening in an Asian population with diverse risk for lung cancer: A retrospective cohort study

    International Nuclear Information System (INIS)

    Yi, Chin A.; Lee, Kyung Soo; Shin, Myung-Hee; Cho, Yun Yung; Choi, Yoon-Ho; Kwon, O. Jung; Shin, Kyung Eun

    2015-01-01

    To evaluate the performance of low-dose CT (LDCT) screening for lung cancer (LCA) detection in an Asian population with diverse risks for LCA. LCA screening was performed in 12,427 symptomless Asian subjects using either LDCT (5,771) or chest radiography (CXR) (6,656) in a non-trial setting. Subjects were divided into high-risk and non-high-risk groups. Data were collected on the number of patients with screening-detected LCAs and their survival in order to compare outcomes between LDCT and CXR screening with the stratification of risks considering age, sex and smoking status. In the non-high-risk group, a significant difference was observed for the detection of lung cancer (adjusted OR, 5.07; 95 % CI, 2.72-9.45) and survival (adjusted HR of LCA survival between LDCT vs. CXR group, 0.08; 95 % CI, 0.01-0.62). No difference in detection or survival of LCA was noticed in the high-risk group. LCAs in the non-high-risk group were predominantly adenocarcinomas (96 %), and more likely to be part-solid or non-solid compared with those in the high-risk group (p = 0.023). In the non-high-risk group, LDCT helps detect more LCAs and offers better survival than CXR screening, due to better detection of part solid or non-solid lung adenocarcinomas. (orig.)

  2. Low-dose CT screening in an Asian population with diverse risk for lung cancer: A retrospective cohort study

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Chin A. [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Lee, Kyung Soo [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Shin, Myung-Hee; Cho, Yun Yung [Sungkyunkwan University School of Medicine, Department of Social and Preventive Medicine, Seoul (Korea, Republic of); Choi, Yoon-Ho [Sungkyunkwan University School of Medicine, Center for Health Promotion, Seoul (Korea, Republic of); Kwon, O. Jung [Sungkyunkwan University School of Medicine, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Seoul (Korea, Republic of); Shin, Kyung Eun [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Kyung Hee University Hospital, Department of Diagnostic Radiology, Seoul (Korea, Republic of)

    2015-08-15

    To evaluate the performance of low-dose CT (LDCT) screening for lung cancer (LCA) detection in an Asian population with diverse risks for LCA. LCA screening was performed in 12,427 symptomless Asian subjects using either LDCT (5,771) or chest radiography (CXR) (6,656) in a non-trial setting. Subjects were divided into high-risk and non-high-risk groups. Data were collected on the number of patients with screening-detected LCAs and their survival in order to compare outcomes between LDCT and CXR screening with the stratification of risks considering age, sex and smoking status. In the non-high-risk group, a significant difference was observed for the detection of lung cancer (adjusted OR, 5.07; 95 % CI, 2.72-9.45) and survival (adjusted HR of LCA survival between LDCT vs. CXR group, 0.08; 95 % CI, 0.01-0.62). No difference in detection or survival of LCA was noticed in the high-risk group. LCAs in the non-high-risk group were predominantly adenocarcinomas (96 %), and more likely to be part-solid or non-solid compared with those in the high-risk group (p = 0.023). In the non-high-risk group, LDCT helps detect more LCAs and offers better survival than CXR screening, due to better detection of part solid or non-solid lung adenocarcinomas. (orig.)

  3. [Low-dose aspirin in patients with diabete melitus: risks and benefits regarding macro and microvascular complications].

    Science.gov (United States)

    Camargo, Eduardo G; Gross, Jorge Luiz; Weinert, Letícia S; Lavinsky, Joel; Silveiro, Sandra P

    2007-04-01

    Aspirin is recommended as cardiovascular disease prevention in patients with diabetes mellitus. Due to the increased risk of bleeding and because of the hypothesis that there could be a worsening of microvascular complications related to aspirin, there has been observed an important underutilization of the drug. However, it is now known that aspirin is not associated with a deleterious effect on diabetic retinopathy and there is evidence indicating that it also does not affect renal function with usual doses (150 mg/d). On the other hand, higher doses may prove necessary, since recent data suggest that diabetic patients present the so called "aspirin resistance". The mechanisms of this resistance are not yet fully understood, being probably related to an abnormal intrinsic platelet activity. The employment of alternative antiplatelet strategies or the administration of higher aspirin doses (150-300 mg/d) should be better evaluated regarding effective cardiovascular disease prevention in diabetes as well as the possible effects on microvascular complications.

  4. Estimation of frequency, population doses and stochastic risks in brachytherapy in Japan, 1983

    International Nuclear Information System (INIS)

    Maruyama, Takashi; Kumamoto, Yoshikazu; Noda, Yutaka; Nishizawa, Kanae; Furuya, Yoshiro; Iwai, Kazuo.

    1988-01-01

    Based on the replies to a questionnaire distributed throughout Japan in 1983, genetically significant dose (GSD), per Caput mean bone marrow dose (CMD), leukemogenically significant dose (LSD), malignantly significant dose (MSD), and per Caput effective dose equivalent (EDE) from using small sealed radiation sources for radiotherapy were estimated. Annual frequencies of brachytherapy were estimated to be 2.6 x 10 3 for men and 36.3 x 10 3 for women, with a total of 38.9 x 10 3 . The annual frequencies of using afterloading technique were 0.3 x 10 3 for men and 18.8 x 10 3 for women, with a total of 19.1 x 10 3 . The annual population doses per person were 7.9 nGy for GSD, 118 μGy for CMD, 19.3 μGy for LSD, 172 μGy for MSD, and 428 μGy for EDE. The annual collective effective dose equivalent was estimated to be 5.13 x 10 4 man Sv. (Namekawa, K.)

  5. Soy food intake and risk of gastric cancer: A dose-response meta-analysis of prospective studies.

    Science.gov (United States)

    Weng, Ke-Gui; Yuan, Ya-Ling

    2017-08-01

    Epidemiological studies were inconsistent on the association between soy food intake and risk of gastric cancer (GC). This study aimed to determine the role of soy food intake in the development of GC.A systematic search was conducted in PubMed and Web of Science to identify all relevant studies. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were pooled using a random-effects model, and the dose-response relationship between soy food intake and GC risk was also assessed.Thirteen prospective studies were identified with a total of 517,106 participants and 5800 cases. Among 11 types of soy food, high intake of total soy food (the highest vs the lowest category: RR: 0.78, 95% CI: 0.62-0.98) and nonfermented soy food (RR: 0.63, 95% CI: 0.50-0.79) were inversely associated with GC risk, while high intake of miso soup was associated with the risk in male (RR: 1.17, 95% CI: 1.02-1.36). In dose-response meta-analysis, total soy food intake (0-150 g/day) showed no significant association with GC risk, while high intake of nonfermented soy food was inversely related, especially an intake of more than 100 g/day. In male, miso soup intake (1-5 cups/day) was significantly associated with GC risk.High intake of nonfermented soy food might reduce the risk of GC, while miso soup intake might increase the risk in male.

  6. Radiation-Induced Rib Fractures After Hypofractionated Stereotactic Body Radiation Therapy: Risk Factors and Dose-Volume Relationship

    Energy Technology Data Exchange (ETDEWEB)

    Asai, Kaori [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Shioyama, Yoshiyuki, E-mail: shioyama@radiol.med.kyushu-u.ac.jp [Department of Heavy Particle Therapy and Radiation Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Nakamura, Katsumasa; Sasaki, Tomonari; Ohga, Saiji; Nonoshita, Takeshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Yoshitake, Tadamasa [Department of Heavy Particle Therapy and Radiation Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Ohnishi, Kayoko [Department of Radiology, National Center for Global Health and Medicine, Tokyo (Japan); Terashima, Kotaro; Matsumoto, Keiji [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Hirata, Hideki [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Honda, Hiroshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)

    2012-11-01

    Purpose: The purpose of this study was to clarify the incidence, the clinical risk factors, and the dose-volume relationship of radiation-induced rib fracture (RIRF) after hypofractionated stereotactic body radiation therapy (SBRT). Methods and Materials: One hundred sixteen patients treated with SBRT for primary or metastatic lung cancer at our institution, with at least 6 months of follow-up and no previous overlapping radiation exposure, were included in this study. To determine the clinical risk factors associated with RIRF, correlations between the incidence of RIRF and the variables, including age, sex, diagnosis, gross tumor volume diameter, rib-tumor distance, and use of steroid administration, were analyzed. Dose-volume histogram analysis was also conducted. Regarding the maximum dose, V10, V20, V30, and V40 of the rib, and the incidences of RIRF were compared between the two groups divided by the cutoff value determined by the receiver operating characteristic curves. Results: One hundred sixteen patients and 374 ribs met the inclusion criteria. Among the 116 patients, 28 patients (46 ribs) experienced RIRF. The estimated incidence of rib fracture was 37.7% at 3 years. Limited distance from the rib to the tumor (<2.0 cm) was the only significant risk factor for RIRF (p = 0.0001). Among the dosimetric parameters used for receiver operating characteristic analysis, the maximum dose showed the highest area under the curve. The 3-year estimated risk of RIRF and the determined cutoff value were 45.8% vs. 1.4% (maximum dose, {>=}42.4 Gy or less), 51.6% vs. 2.0% (V40, {>=}0.29 cm{sup 3} or less), 45.8% vs. 2.2% (V30, {>=}1.35 cm{sup 3} or less), 42.0% vs. 8.5% (V20, {>=}3.62 cm{sup 3} or less), or 25.9% vs. 10.5% (V10, {>=}5.03 cm{sup 3} or less). Conclusions: The incidence of RIRF after hypofractionated SBRT is relatively high. The maximum dose and high-dose volume are strongly correlated with RIRF.

  7. Radioablation of liver malignancies with interstitial high-dose-rate brachytherapy. Complications and risk factors

    Energy Technology Data Exchange (ETDEWEB)

    Mohnike, Konrad; Wolf, Steffen; Damm, Robert; Seidensticker, Max; Seidensticker, Ricarda; Fischbach, Frank; Pech, Maciej; Ricke, Jens [Otto-von-Guericke-Universitaet, Klinik fuer Radiologie und Nuklearmedizin, Universitaetsklinikum Magdeburg A.oe.R., Magdeburg (Germany); Peters, Nils; Hass, Peter; Gademann, Guenther [Otto-von-Guericke-Universitaet, Klinik fuer Strahlentherapie, Universitaetsklinikum Magdeburg A.oe.R., Magdeburg (Germany)

    2016-05-15

    To evaluate complications and identify risk factors for adverse events in patients undergoing high-dose-rate interstitial brachytherapy (iBT). Data from 192 patients treated in 343 CT- or MRI-guided interventions from 2006-2009 at our institution were analyzed. In 41 %, the largest tumor treated was ≥ 5 cm, 6 % of the patients had tumors ≥ 10 cm. Prior to iBT, 60 % of the patients had chemotherapy, 22 % liver resection, 19 % thermoablation or transarterial chemoembolization (TACE). Safety was the primary endpoint; survival data were obtained as the secondary endpoints. During follow-up, MRI or CT imaging was performed and clinical and laboratory parameters were obtained. The rate of major complications was below 5 %. Five major bleedings (1.5 %) occurred. The frequency of severe bleeding was significantly higher in patients with advanced liver cirrhosis. One patient developed signs of a nonclassic radiation-induced liver disease. In 3 patients, symptomatic gastrointestinal (GI) ulcers were detected. A dose exposure to the GI wall above 14 Gy/ml was a reliable threshold to predict ulcer formation. A combination of C-reactive protein ≥ 165 mg/l and/or leukocyte count ≥ 12.7 Gpt/l on the second day after the intervention predicted infection (sensitivity 90.0 %; specificity 92.8 %.) Two patients (0.6 %) died within 30 days. Median overall survival after the first liver treatment was 20.1 months for all patients and the local recurrence-free surviving proportion was 89 % after 12 months. Image-guided iBT yields a low rate of major complications and is effective. (orig.) [German] Evaluierung der Komplikationsrate und Identifizierung von Risikofaktoren fuer Komplikationen und Nebenwirkungen bei Patienten mit Lebermalignomen, die mit der hochdosierten interstitiellen Brachytherapie (iBT) behandelt wurden. Von 2006 bis 2009 wurden 192 Patienten in 343 CT- oder MRT-gefuehrten Interventionen behandelt und deren Daten ausgewertet. Der groesste behandelte Tumor war in

  8. Influence of Comorbidity on the Risk of Mortality in Men With Unfavorable-Risk Prostate Cancer Undergoing High-Dose Radiation Therapy Alone

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, Mai Anh, E-mail: mahuynh@lroc.harvard.edu [Harvard Radiation Oncology Program, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Chen, Ming-Hui; Wu, Jing [Department of Statistics, University of Connecticut, Storrs, Connecticut (United States); Braccioforte, Michelle H.; Moran, Brian J. [Prostate Cancer Foundation of Chicago, Westmont, Illinois (United States); D' Amico, Anthony V. [Department of Radiation Oncology, Brigham and Women' s Hospital–Dana-Farber Cancer Institute, Boston, Massachusetts (United States)

    2016-07-15

    Purpose: To explore whether a subgroup of men with unfavorable-risk prostate cancer (PC) exists in whom high-dose radiation therapy (RT) alone is sufficient to avoid excess PC death due to competing risk from cardiometabolic comorbidity. Methods and Materials: This was a cohort study of 7399 men in whom comorbidity (including congestive heart failure, diabetes mellitus, or myocardial infarction) was assessed and recorded with T1-3NxM0 PC treated with brachytherapy with or without neoadjuvant RT, October 1997 to May 2013 at a single providing institution. Cox and competing risks regression analyses were used to assess whether men with unfavorable–intermediate/high-risk versus favorable–intermediate/low-risk PC were at increased risk of PC-specific, all-cause, or other-cause mortality (PCSM, ACM, OCM), adjusting for number of comorbidities, age at and year of brachytherapy, RT use, and an RT treatment propensity score. Results: After a median follow-up of 7.7 years, 935 men died: 80 of PC and 855 of other causes. Among men with no comorbidity, PCSM risk (adjusted hazard ratio [AHR] 2.74 [95% confidence interval (CI) 1.49-5.06], P=.001) and ACM risk (AHR 1.30 [95% CI 1.07-1.58], P=.007) were significantly increased in men with unfavorable–intermediate/high-risk PC versus favorable–intermediate/low-risk PC, with no difference in OCM (P=.07). Although PCSM risk was increased in men with 1 comorbidity (AHR 2.87 [95% CI 1.11-7.40], P=.029), ACM risk was not (AHR 1.03 [95% CI 0.78-1.36], P=.84). Neither PCSM risk (AHR 4.39 [95% CI 0.37-51.98], P=.24) or ACM risk (AHR 1.43 [95% CI 0.83-2.45], P=.20) was increased in men with 2 comorbidities. Conclusions: To minimize death from PC, high-dose RT alone may be sufficient treatment in men with 2 or more cardiometabolic comorbidities and unfavorable–intermediate- and high-risk PC.

  9. Assessing the Risk of Birth Defects Associated with Exposure to Fixed-Dose Combined Antituberculous Agents during Pregnancy in Rats

    Directory of Open Access Journals (Sweden)

    O. Awodele

    2012-01-01

    Full Text Available Due to the risks of disease progression and transmission to the newborn, treatment of tuberculosis is often pursued during pregnancy and fixed-dose combined antituberculous agents have been found to be beneficial. Unfortunately, there is paucity of data on the safety of the fixed-dose combined antituberculous drugs during pregnancy. This study intends to assess the teratogenic effect of fixed-dose combined antituberculous drugs on the organogenesis stage of fetal development and also investigate the possible roles of vitamin C in modulating the teratogenic effects of these agents on the fetus using animal model. Pregnant rats were divided into 3 groups with 12 animals per group: group 1 received distilled water (10 mL/kg orally; group 2 received 51.4 mg/kg/day of fixed-dose combined antituberculous agents orally; group 3 received 51.4 mg/kg/day of fixed-dose combined antituberculous agents plus vitamin C (10 mg/kg/day orally. Six rats in each group were randomly selected and sacrificed on day 20 by cervical dislocation prior to day 21 of gestation, and the foetuses were harvested through abdominal incision for physical examination. Blood samples were collected from the 1st filial rats of the remaining six animals for biochemical and hematological examination. The liver, kidney, heart, and brain of all the sacrificed animals were used for histopathological examination. There were significant (≤0.05 low birth weights of the foetuses of the animals that were treated with fixed-dose combined antituberculous agents. The haematological parameters also revealed a reduction in the platelets counts and neutrophiles at the first filial generation. Significant (≤0.05 elevations in the levels of aspartate aminotransferase (AST and alkaline phosphatase (ALP in the foetuses of the animals treated with fixed-dose combined antituberculous agents were also observed. However, the combination of vitamin C with fixed-dose combined antituberculous agents

  10. Occupational exposure to radon for underground tourist routes in Poland: Doses to lung and the risk of developing lung cancer

    Directory of Open Access Journals (Sweden)

    Katarzyna Walczak

    2017-10-01

    Full Text Available Objectives: Radon concentrations for 31 Polish underground tourist routes were analyzed. The equivalent dose to the lung, the effective dose and the relative risk were calculated for employees of the analyzed routes on the grounds of information on radon concentrations, work time, etc. Material and Methods: The relative risk for lung cancers was calculated using the Biological Effects of Ionizing Radiation (BEIR VI Committee model. Equivalent doses to the lungs of workers were determined using the coefficients calculated by the Kendall and Smith. The conversion coefficient proposed by the International Atomic Energy Agency (IAEA in the report No. 33 was used for estimating the effective doses. Results: In 13 routes, the effective dose was found to be above 1 mSv/year, and in 3 routes, it exceeded 6 mSv/year. For 5 routes, the equivalent dose to lungs was higher than 100 mSv/year, and in 1 case it was as high as 490 mSv/year. In 22.6% of underground workplaces the risk of developing lung cancer among employees was about 2 times higher than that for the general population, and for 1 tourist route it was about 5 times higher. The geometric mean of the relative risk of lung cancer for all workers of underground tourist routes was 1.73 (95% confidence interval (CI: 1.6–1.87. Routes were divided into: caves, mines, post-military underground constructions and urban underground constructions. Conclusions: The difference between levels of the relative risk of developing lung cancer for all types of underground tourist routes was not found to be significant. If we include the professional group of the employees of underground tourist routes into the group of occupational exposure, the number of persons who are included in the Category A due to occupational exposure may increase by about 3/4. The professional group of the employees of underground tourist routes should be monitored for their exposure to radon. Int J Occup Med Environ Health 2017;30(5:687

  11. Occupational exposure to radon for underground tourist routes in Poland: Doses to lung and the risk of developing lung cancer.

    Science.gov (United States)

    Walczak, Katarzyna; Olszewski, Jerzy; Politański, Piotr; Zmyślony, Marek

    2017-07-14

    Radon concentrations for 31 Polish underground tourist routes were analyzed. The equivalent dose to the lung, the effective dose and the relative risk were calculated for employees of the analyzed routes on the grounds of information on radon concentrations, work time, etc. The relative risk for lung cancers was calculated using the Biological Effects of Ionizing Radiation (BEIR) VI Committee model. Equivalent doses to the lungs of workers were determined using the coefficients calculated by the Kendall and Smith. The conversion coefficient proposed by the International Atomic Energy Agency (IAEA) in the report No. 33 was used for estimating the effective doses. In 13 routes, the effective dose was found to be above 1 mSv/year, and in 3 routes, it exceeded 6 mSv/year. For 5 routes, the equivalent dose to lungs was higher than 100 mSv/year, and in 1 case it was as high as 490 mSv/year. In 22.6% of underground workplaces the risk of developing lung cancer among employees was about 2 times higher than that for the general population, and for 1 tourist route it was about 5 times higher. The geometric mean of the relative risk of lung cancer for all workers of underground tourist routes was 1.73 (95% confidence interval (CI): 1.6-1.87). Routes were divided into: caves, mines, post-military underground constructions and urban underground constructions. The difference between levels of the relative risk of developing lung cancer for all types of underground tourist routes was not found to be significant. If we include the professional group of the employees of underground tourist routes into the group of occupational exposure, the number of persons who are included in the Category A due to occupational exposure may increase by about 3/4. The professional group of the employees of underground tourist routes should be monitored for their exposure to radon. Int J Occup Med Environ Health 2017;30(5):687-694. This work is available in Open Access model and licensed under a CC

  12. Bright-light intervention induces a dose-dependent increase in striatal response to risk in healthy volunteers

    DEFF Research Database (Denmark)

    Macoveanu, Julian; Fisher, Patrick M; Madsen, Martin K

    2016-01-01

    Bright-light interventions have successfully been used to reduce depression symptoms in patients with seasonal affective disorder, a depressive disorder most frequently occurring during seasons with reduced daylight availability. Yet, little is known about how light exposure impacts human brain...... function, for instance on risk taking, a process affected in depressive disorders. Here we examined the modulatory effects of bright-light exposure on brain activity during a risk-taking task. Thirty-two healthy male volunteers living in the greater Copenhagen area received 3weeks of bright......-light intervention during the winter season. Adopting a double-blinded dose-response design, bright-light was applied for 30minutes continuously every morning. The individual dose varied between 100 and 11.000lx. Whole-brain functional MRI was performed before and after bright-light intervention to probe how...

  13. External exposure dose of car mechanics during the maintenance of the cars from the risk cautionary area

    International Nuclear Information System (INIS)

    Kawakami, Hiroto; Yamada, Norikazu; Sasaki, Satoru; Kawasaki, Satoru

    2011-12-01

    At the request of the Local Nuclear Emergency Response Headquarters, JNES has estimated the effective external exposure dose of car mechanics during the maintenance of the cars from the risk cautionary area. JNES investigated the contamination of the cars from the risk cautionary area and of the average cars at Fukushima city cooperated by the Japan Automobile Dealers Association. Data of screed cars by the Local Nuclear Emergency Response Headquarters is also considered in. Effective external exposure dose of car mechanics treating the cars screened with the emergency situation screening level is estimated to be less than 1 mSv/y under the conservative conditions. This result shows that particular health concern isn't necessary for them. (author)

  14. Role of prostate dose escalation in patients with greater than 15% risk of pelvic lymph node involvement

    International Nuclear Information System (INIS)

    Jacob, Rojymon; Hanlon, Alexandra L.; Horwitz, Eric M.; Movsas, Benjamin; Uzzo, Robert G.; Pollack, Alan

    2005-01-01

    Purpose: To determine whether the radiation dose is a determinant of clinical outcome in patients with a lymph node risk of >15% treated using whole pelvic (WP), partial pelvic (PP), or prostate only (PO) fields. Methods and materials: A total of 420 patients with prostate cancer treated with three-dimensional conformal radiotherapy with or without short-term androgen deprivation (STAD) between June 1989 and July 2000 were included in this study. Patients had an initial pretreatment prostate-specific antigen level of 15% in the patient population studied. These data suggest that the primary tumor takes precedence over lymph node coverage or the use of STAD. Doses >70 Gy are of paramount importance in such intermediate- and high-risk patients

  15. Association between tea consumption and risk of cognitive disorders: A dose-response meta-analysis of observational studies.

    Science.gov (United States)

    Liu, Xueying; Du, Xiaoyuan; Han, Guanying; Gao, Wenyuan

    2017-06-27

    The epidemiological evidence for a dose-response relationship between tea consumption and risk of cognitive disorders is sparse. The aim of the study was to summarize the evidence for the association of tea consumption with risk of cognitive disorders and assess the dose-response relationship. We searched electronic databases of Pubmed, Embase, and Cochrane Library (from 1965 to Jan 19, 2017) for eligible studies that published in the international journals. A random-effects model was used to pool the most adjusted odds ratios (ORs) and the corresponding 95% confidence intervals (CIs). Seventeen studies involving 48,435 participants were included in our study. The meta-analysis showed that a higher tea consumption was associated with a significant reduction in the risk of cognitive disorders (OR=0.73, 95% CI: 0.65-0.82). When considering the specific types of tea consumption, the significantly inverse association is only found in green tea consumption (OR=0.64, 95% CI: 0.53-0.77) but not in black/oolong tea consumption (OR=0.75, 95% CI: 0.55-1.01). Dose-response meta-analysis indicated that tea consumption is linearly associated with a reduced risk of cognitive disorders. An increment of 100 ml/day, 300 ml/day, and 500 ml/day of tea consumption was associated with a 6% (OR=0.94, 95% CI: 0.92-0.96), 19% (OR=0.81, 95% CI: 0.74-0.88), and 29% (OR=0.71, 95% CI: 0.62-0.82) lower risk of cognitive disorders. Tea consumption is inversely and linearly related to the risk of cognitive disorders. More studies are needed to further confirm our findings.

  16. Radiation dose and long term risk of cardiac pathology following radiotherapy and anthracyclin for a childhood cancer

    International Nuclear Information System (INIS)

    Guldner, Laurence; Haddy, Nadia; Pein, Francois; Diallo, Ibrahima; Shamsaldin, Akthar; Dahan, Michel; Lebidois, Jerome; Merlet, Pascal; Villain, Elisabeth; Sidi, Daniel; Sakiroglu, Olivia; Hartmann, Olivier; Leftakopoulos, Dimitri; Vathaire, Florent de

    2006-01-01

    Purpose: To determine the cardiac status in children 15 years (yrs) or more after a solid tumour treatment. Patients and Methods: Of the 447 patients, 229 were fully studied and 218 were not. The following cardiac evaluation was proposed to all the 447 consecutive patients: (1) cardiac Doppler US by one of two expert cardiologists; (2) cardiac rhythm and conduction abnormalities including 24-h holter ECG; (3) 131 I-mIBG myocardial scintigraphy; (4) serum brain natriuretic peptide levels at rest; (5) an exercise test with VO 2 max measurement. The radiation dose delivered to 7 points in the heart was estimated for all patients who had received radiotherapy. Results: Cardiac disorder was diagnosed in 89 evaluated patients (39%) including 24 heart failures and 65 other asymptomatic cardiac diseases. When adjusting on potential confounders, cardiac disorder and cardiac failure risks were respectively linear (ERR at 1 Gy: 26%) and linear-quadratic (ERR at 1 Gy: 19%) functions of the average radiation dose received to the heart. No interaction between cumulative dose of adriamycin and average radiation dose was evidenced for cardiac disorders, but the ERR/Gy of cardiac failure was higher for patients receiving less than 350 mg/m 2 of Adriamycin. Conclusion: Long term heart pathologies are probably one of the major iatrogenic risks encored by patients who survived a childhood cancer. This study strongly emphasizes the need to limit the heart irradiation during radiotherapy, particularly, for patients who also received or were susceptible to later received adriamycin

  17. Use of BEIR V and UNSCEAR 1988 in radiation risk assessment: Lifetime total cancer mortality risk estimates at low doses and low dose rates for low-LET radiation

    International Nuclear Information System (INIS)

    1992-12-01

    In November 1986, the Department of Defense (DoD) asked the Committee on Interagency Radiation Research and Policy Coordination (CIRRPC) to develop a coordinated Federal position on risk assessment for low levels of ionizing radiation. Since Federal risk assessment activities are based primarily on the scientific data and analyses in authoritative review documents prepared by groups like the National Academy of Sciences' Committee on the Biological Effects of Ionizing Radiation (BEIR), the National Council on Radiation Protection and Measurements (NCRP) and the United Nations' Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), DoD proposed that the CIRRPC Science Panel undertake the task of providing coordinated interagency positions on the use of information in the reports of such groups. The practice has been for individual Federal agencies to interpret and decide independently how to use the information provided in such reports. As a result of its deliberations, the Subpanel recommends two nominal risk estimates for lifetime total cancer mortality following whole-body exposure to low levels of low-LET ionizing radiation, one for the general population and one for the working-age population (see Section II). The recommended risk estimates reflect the general agreement of information in BEIR V and UNSCEAR 1988 for total cancer mortality. The Subpanel's risk estimates and associated statements are intended to meet the needs of the Federal agencies for: (a) values that are current; (b) values that are relevant to the low-dose and low dose-rate ionizing radiation exposures principally encountered in carrying out Federal responsibilities; (c) a statement of the change in the estimates of lifetime total cancer mortality relative to estimates in previous authoritative review documents; and (d) a practical statement on the scientific uncertainty associated with applying the lifetime total cancer mortality values at very low doses

  18. Baseline assessment of doses and risk due to natural radionuclides in edible biota of Domiasiat, Meghalaya, India

    International Nuclear Information System (INIS)

    Kumar, N.; Chaturvedi, S.S.; Jha, S.K.

    2011-01-01

    Radiation dose-risk assessment was carried out for cereal species Brassica compestris var. dichotoma, Oryza sativa var. Shalum1, Zea mays, Lactuca indica, Cumunis sativum, and Clocasia esculanta due to naturally available radionuclides 40 K, 238 U and 232 Th in Domiasiat area. The activity in biota and corresponding soil was measured by precipitation method using NaI(TI) detector. Transfer factor (TF) was for Oryza spp. (1.00E-01- 40 K, 8.76E-05- 232 Th, and 9.11E-05- 238 U), for Brassica spp. (5.39E-01- 40 K, 8.17E-04- 232 Th and 2.96E-04- 238 U) and for Zea spp. (3.41E-01- 40 K, 5.84E-05- 232 Th, 8.87E-05- 238 U) etc., respectively. A detailed physio-morphological study of the biota and extensive investigation of ecosystem was carried out for assessment. The data was modeled using FASSET for dose estimation and obtained total dose was 1.58E-04 μGy h -1 in Oryza spp., 2.87E-04 μGy h -1 Brassica spp. and 6.90E-03 μGy h -1 in Zea spp. etc. The dose was compared with the UNSCEAR dataset for screening level dose for biota. Zea spp. was more susceptible for the chronic radiation exposure. (author)

  19. The Increase in Animal Mortality Risk following Exposure to Sparsely Ionizing Radiation Is Not Linear Quadratic with Dose.

    Directory of Open Access Journals (Sweden)

    Benjamin M Haley

    Full Text Available The US government regulates allowable radiation exposures relying, in large part, on the seventh report from the committee to estimate the Biological Effect of Ionizing Radiation (BEIR VII, which estimated that most contemporary exposures- protracted or low-dose, carry 1.5 fold less risk of carcinogenesis and mortality per Gy than acute exposures of atomic bomb survivors. This correction is known as the dose and dose rate effectiveness factor for the life span study of atomic bomb survivors (DDREFLSS. It was calculated by applying a linear-quadratic dose response model to data from Japanese atomic bomb survivors and a limited number of animal studies.We argue that the linear-quadratic model does not provide appropriate support to estimate the risk of contemporary exposures. In this work, we re-estimated DDREFLSS using 15 animal studies that were not included in BEIR VII's original analysis. Acute exposure data led to a DDREFLSS estimate from 0.9 to 3.0. By contrast, data that included both acute and protracted exposures led to a DDREFLSS estimate from 4.8 to infinity. These two estimates are significantly different, violating the assumptions of the linear-quadratic model, which predicts that DDREFLSS values calculated in either way should be the same.Therefore, we propose that future estimates of the risk of protracted exposures should be based on direct comparisons of data from acute and protracted exposures, rather than from extrapolations from a linear-quadratic model. The risk of low dose exposures may be extrapolated from these protracted estimates, though we encourage ongoing debate as to whether this is the most valid approach. We also encourage efforts to enlarge the datasets used to estimate the risk of protracted exposures by including both human and animal data, carcinogenesis outcomes, a wider range of exposures, and by making more radiobiology data publicly accessible. We believe that these steps will contribute to better estimates

  20. Assessment of patient dose and radiogenic risks during endoscopic retrograde cholangiopancreatography

    Energy Technology Data Exchange (ETDEWEB)

    Sulieman, A.; Elzaki, M. [Sudan University of Science and Technology, College of Medical Radiologic Science, P. O. Box 1908, Khartoum 11111 (Sudan); Alkhorayef, M.; Babikir, E. [King Saud University, College of Applied Sciences, Radiological Sciences Department, P. O. Box 10219, Riyadh 11433 (Saudi Arabia); Abuzaid, M. [University of Sharjah, College of Health Sciences, Medical Diagnostic Imaging Department, Sharjah (United Arab Emirates); Dalton, A.; Bradley, D., E-mail: Abdelmoneim_a@yahoo.com [University of Surrey, Centre for Nuclear and Radiation Physics, Department of Physics, GU2-7XH, Guildford, Surrey (United Kingdom)

    2015-10-15

    Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive technique that has been used for over 30 years in the diagnosis and management of pancreaticobiliary disorders. The objectives of this study were to evaluate the patient entrance surface air kerma doses (ESAK) and estimate the organ and effective doses during ERCP in three hospitals in Khartoum. A total of 55 patients were examined in three hospitals in Khartoum state, Sudan. Calibrated thermoluminescence dosimeters (TLD)-Gr-200-A)) were used to measure patients ESAK. The overall mean of ESAK for all ERCP procedures was 42.4 mGy. The mean patient ESAK in Fedail, Soba and Ibn sena centers were 26.7 mGy, 26.0 mGy, 72.4 mGy, respectively. The effective doses in three centers were 1.6, 1.56 and 2.67 mSv in that order and the overall mean effective dose was 2.01 mSv. Patient radiation doses vary widely among the different hospitals. Patient ESAK is low compared to previous studies in the light of the current practice. Patient dose was decreased significantly in the last two decades. (Author)

  1. Assessment of patient dose and radiogenic risks during endoscopic retrograde cholangiopancreatography

    International Nuclear Information System (INIS)

    Sulieman, A.; Elzaki, M.; Alkhorayef, M.; Babikir, E.; Abuzaid, M.; Dalton, A.; Bradley, D.

    2015-10-01

    Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive technique that has been used for over 30 years in the diagnosis and management of pancreaticobiliary disorders. The objectives of this study were to evaluate the patient entrance surface air kerma doses (ESAK) and estimate the organ and effective doses during ERCP in three hospitals in Khartoum. A total of 55 patients were examined in three hospitals in Khartoum state, Sudan. Calibrated thermoluminescence dosimeters (TLD)-Gr-200-A)) were used to measure patients ESAK. The overall mean of ESAK for all ERCP procedures was 42.4 mGy. The mean patient ESAK in Fedail, Soba and Ibn sena centers were 26.7 mGy, 26.0 mGy, 72.4 mGy, respectively. The effective doses in three centers were 1.6, 1.56 and 2.67 mSv in that order and the overall mean effective dose was 2.01 mSv. Patient radiation doses vary widely among the different hospitals. Patient ESAK is low compared to previous studies in the light of the current practice. Patient dose was decreased significantly in the last two decades. (Author)

  2. Use of low-dose aspirin and non-aspirin nonsteroidal anti-inflammatory drugs and risk of glioma

    DEFF Research Database (Denmark)

    Gaist, David; García-Rodríguez, L A; Sørensen, H T

    2013-01-01

    Background:Few studies have examined the association between use of aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) and risk of glioma and the results have been equivocal. We therefore investigated the influence of NSAID use on glioma risk in a nationwide setting.Methods:We used...... exposure to low-dose aspirin or non-aspirin (NA) NSAIDs into ever use or long-term use, defined as continuous use for 5 years. Conditional logistic regression was used to compute odds ratios (ORs), with 95% confidence intervals (CIs), for glioma associated with NSAID use, adjusted for potential...... confounders.Results:A total of 2688 glioma cases and 18 848 population controls were included in the study. Ever use of low-dose aspirin (OR=0.90; 95% CI: 0.77-1.04) or NA-NSAIDs (OR=1.05; 95% CI: 0.96-1.14) was not associated with glioma risk. Compared with never use, long-term use of low-dose aspirin...

  3. Worry and risk perception of breast cancer in a prevention trial of low dose tamoxifen in midlife postmenopausal hormone users.

    Science.gov (United States)

    Rondanina, Gabriella; Puntoni, Matteo; Guerrieri-Gonzaga, Aliana; Marra, Domenico; Bonanni, Bernardo; DeCensi, Andrea

    2017-08-01

    There is increasing interest in combining postmenopausal hormone therapy (HT) and SERMs in midlife women. We previously showed that refusal to participate in a prevention trial of low dose tamoxifen in HT users was associated with higher worry about breast cancer. Given this counterintuitive finding, we studied which factors influenced worry and risk perception of breast cancer. We assessed the relationships of breast cancer worry and risk perception with age, age at menopause, Gail risk, education, adherence to mammographic screening, BMI, smoking, physical activity, alcohol use, anxiety and depression in 457 midlife HT users who were eligible to participate in the trial. Women with menopause 52 years (OR = 5.0, 95% CI, 1.2-21.1). Worry was also associated with high absolute risk perception and former smoking. Factors associated with higher risk perception were age>60 years, at-risk life style, worry about breast cancer and depression. The inverse association between early menopause and worry about breast cancer is in contrast with the known protective effect of early menopause on breast cancer risk and seems to reflect a feeling of aging and disease vulnerability. Our findings indicate that worry about cancer has an affective construct which is independent of breast cancer biology but is engaged in health decision making. Increasing breast cancer risk awareness in subjects high in worry without a plan of emotional coping may therefore be counterproductive because of avoidant attitudes. Copyright © 2017. Published by Elsevier Ltd.

  4. Human Health Risk Assessment: A case study application of principles in dose response assessment

    Science.gov (United States)

    This case study application workshop will build on fundamental concepts and techniques in risk assessment presented and archived at previous TRAC meeting workshops. Practical examples from publicly available, peer reviewed risk assessments will be used as teaching aids. Course ...

  5. Projected Second Tumor Risk and Dose to Neurocognitive Structures After Proton Versus Photon Radiotherapy for Benign Meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Arvold, Nils D. [Harvard Radiation Oncology Program, Harvard Medical School, Boston, MA (United States); Niemierko, Andrzej; Broussard, George P.; Adams, Judith; Fullerton, Barbara; Loeffler, Jay S. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Shih, Helen A., E-mail: hshih@partners.org [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States)

    2012-07-15

    Purpose: To calculated projected second tumor rates and dose to organs at risk (OAR) in patients with benign intracranial meningioma (BM), according to dosimetric comparisons between proton radiotherapy (PRT) and photon radiotherapy (XRT) treatment plans. Methods and Materials: Ten patients with BM treated at Massachusetts General Hospital during 2006-2010 with PRT were replanned with XRT (intensity-modulated or three-dimensional conformal radiotherapy), optimizing dose to the tumor while sparing OAR. Total dose was 54 Gy in 1.8 Gy per fraction for all plans. We calculated equivalent uniform doses, normal tissue complication probabilities, and whole brain-based estimates of excess risk of radiation-associated intracranial second tumors. Results: Excess risk of second tumors was significantly lower among PRT compared with XRT plans (1.3 vs. 2.8 per 10,000 patients per year, p < 0.002). Mean equivalent uniform doses were lower among PRT plans for the whole brain (19.0 vs. 22.8 Gy, p < 0.0001), brainstem (23.8 vs. 35.2 Gy, p = 0.004), hippocampi (left, 13.5 vs. 25.6 Gy, p < 0.0001; right, 7.6 vs. 21.8 Gy, p = 0.001), temporal lobes (left, 25.8 vs. 34.6 Gy, p = 0.007; right, 25.8 vs. 32.9 Gy, p = 0.008), pituitary gland (29.2 vs. 37.0 Gy, p = 0.047), optic nerves (left, 28.5 vs. 33.8 Gy, p = 0.04; right, 25.1 vs. 31.1 Gy, p = 0.07), and cochleas (left, 12.2 vs. 15.8 Gy, p = 0.39; right,1.5 vs. 8.8 Gy, p = 0.01). Mean normal tissue complication probability was <1% for all structures and not significantly different between PRT and XRT plans. Conclusions: Compared with XRT, PRT for BM decreases the risk of RT-associated second tumors by half and delivers significantly lower doses to neurocognitive and critical structures of vision and hearing.

  6. Projected Second Tumor Risk and Dose to Neurocognitive Structures After Proton Versus Photon Radiotherapy for Benign Meningioma

    International Nuclear Information System (INIS)

    Arvold, Nils D.; Niemierko, Andrzej; Broussard, George P.; Adams, Judith; Fullerton, Barbara; Loeffler, Jay S.; Shih, Helen A.

    2012-01-01

    Purpose: To calculated projected second tumor rates and dose to organs at risk (OAR) in patients with benign intracranial meningioma (BM), according to dosimetric comparisons between proton radiotherapy (PRT) and photon radiotherapy (XRT) treatment plans. Methods and Materials: Ten patients with BM treated at Massachusetts General Hospital during 2006–2010 with PRT were replanned with XRT (intensity-modulated or three-dimensional conformal radiotherapy), optimizing dose to the tumor while sparing OAR. Total dose was 54 Gy in 1.8 Gy per fraction for all plans. We calculated equivalent uniform doses, normal tissue complication probabilities, and whole brain–based estimates of excess risk of radiation-associated intracranial second tumors. Results: Excess risk of second tumors was significantly lower among PRT compared with XRT plans (1.3 vs. 2.8 per 10,000 patients per year, p < 0.002). Mean equivalent uniform doses were lower among PRT plans for the whole brain (19.0 vs. 22.8 Gy, p < 0.0001), brainstem (23.8 vs. 35.2 Gy, p = 0.004), hippocampi (left, 13.5 vs. 25.6 Gy, p < 0.0001; right, 7.6 vs. 21.8 Gy, p = 0.001), temporal lobes (left, 25.8 vs. 34.6 Gy, p = 0.007; right, 25.8 vs. 32.9 Gy, p = 0.008), pituitary gland (29.2 vs. 37.0 Gy, p = 0.047), optic nerves (left, 28.5 vs. 33.8 Gy, p = 0.04; right, 25.1 vs. 31.1 Gy, p = 0.07), and cochleas (left, 12.2 vs. 15.8 Gy, p = 0.39; right,1.5 vs. 8.8 Gy, p = 0.01). Mean normal tissue complication probability was <1% for all structures and not significantly different between PRT and XRT plans. Conclusions: Compared with XRT, PRT for BM decreases the risk of RT-associated second tumors by half and delivers significantly lower doses to neurocognitive and critical structures of vision and hearing.

  7. Radiation doses and risks to neonates undergoing radiographic examinations in intensive care units in Tunisia

    Directory of Open Access Journals (Sweden)

    Abir Bouaoun

    2015-12-01

    Full Text Available Purpose: To assess the radiation doses to neonates from diagnostic radiography in order to derive the local diagnostic reference levels (LDRLs for optimisation purposes.Methods: This study was carried out in the neonatal intensive care units (NICU of  two hospitals in Tunis. 134 babies, with weights ranging from 635 g to 6680 g, performed chest-abdomen X-ray examinations. Neonates were categorized into groups of birth weight. For each X-ray examination, patient data and exposure parameters were recorded. Dose area product (DAP was measured and entrance surface dose (ESD was estimated. Effective dose was calculated from the Monte Carlo simulation software PCXMC.Results: DAP values increased with neonatal weight and demonstrated a wide variation (5.0 - 43.0 mGy.cm2, mean 23.4 mGy.cm2 for patient weight from 600 g to 4000 g. A wide variation was also observed for ESD (14 - 93 μGy, mean 55.2 μGy. The LDRLs expressed in term of DAP were estimated to be 17.6 mGy.cm2 and 29.1 mGy.cm2 for the first and the second NICU, respectively. In terms of effective dose, the average value was about 31.6 μSv per single radiological examination. The results show the necessity to use a standardized protocol with high voltage technique combined to lower current time product (mAs values and an adapted collimation which could lead to further reductions in the neonatal doses. Conclusion: This study presents the LDRLs and the effective doses for neonates in two NICUs and demonstrates the necessity to optimize patient protection for this category of patient.

  8. Doses of low level ionizing radiation; a misunderstood risk, however unavoidable

    International Nuclear Information System (INIS)

    Nicolli, D.

    1988-01-01

    The treatment given by international organizations and associations to the problems of radiation exposures, and the recommendations and norms for calculating risks of low level radiation are analysed. It is shown that there are not zero risks for nuclear energy, and emphasis is given to the risks of natural radiation from environment. (M.C.K.) [pt

  9. Infradiaphragmatic irradiation and high procarbazine doses increase colorectal cancer risk in Hodgkin lymphoma survivors

    NARCIS (Netherlands)

    van Eggermond, Anna M.; Schaapveld, Michael; Janus, Cécile Pm; de Boer, Jan Paul; Krol, Augustinus Dg; Zijlstra, Josée M.; van der Maazen, Richard Wm; Kremer, Leontien C.; van Leerdam, Monique E.; Louwman, Marieke Wj; Visser, Otto; de Bruin, Marie L.; Aleman, Berthe Mp; van Leeuwen, Flora E.

    2017-01-01

    Hodgkin lymphoma (HL) survivors are at increased risk of second malignancies, but few studies have assessed colorectal cancer (CRC) risk after HL treatment. We assessed long-term, subsite-specific CRC risk associated with specific radiation fields and chemotherapy regimens. In a Dutch cohort of 3121

  10. Infradiaphragmatic irradiation and high procarbazine doses increase colorectal cancer risk in Hodgkin lymphoma survivors

    NARCIS (Netherlands)

    Eggermond, A.M. van; Schaapveld, M.; Janus, C.P.; Boer, J.P. de; Krol, A.D.; Zijlstra, J.M.; Maazen, R.W.M. van der; Kremer, L.C.; Leerdam, M.E. van; Louwman, M.W.; Visser, O; Bruin, M.L. De; Aleman, B.M.; Leeuwen, F.E. van

    2017-01-01

    BACKGROUND: Hodgkin lymphoma (HL) survivors are at increased risk of second malignancies, but few studies have assessed colorectal cancer (CRC) risk after HL treatment. We assessed long-term, subsite-specific CRC risk associated with specific radiation fields and chemotherapy regimens. METHODS: In a

  11. Lifetime attributable risk as an alternative to effective dose to describe the risk of cancer for patients in diagnostic and therapeutic nuclear medicine

    Science.gov (United States)

    Andersson, Martin; Eckerman, Keith; Mattsson, Sören

    2017-12-01

    The aim of this study is to implement lifetime attributable risk (LAR) predictions of cancer for patients of various age and gender, undergoing diagnostic investigations or treatments in nuclear medicine and to compare the outcome with a population risk estimate using effective dose and the International Commission on Radiological Protection risk coefficients. The radiation induced risk of cancer occurrence (incidence) or death from four nuclear medicine procedures are estimated for both male and female between 0 and 120 years. Estimations of cancer risk are performed using recommended administered activities for two diagnostic (18F-FDG and 99mTc-phosphonate complex) and two therapeutic (131I-iodide and 223Ra-dichloride) radiopharmaceuticals to illustrate the use of cancer risk estimations in nuclear medicine. For 18F-FDG, the cancer incidence for a male of 5, 25, 50 and 75 years at exposure is 0.0021, 0.0010, 0.0008 and 0.0003, respectively. For 99mTc phosphonates complex the corresponding values are 0.000 59, 0.000 34, 0.000 27 and 0.000 13, respectively. For an 131I-iodide treatment with 3.7 GBq and 1% uptake 24 h after administration, the cancer incidence for a male of 25, 50 and 75 years at exposure is 0.041, 0.029 and 0.012, respectively. For 223Ra-dichloride with an administration of 21.9 MBq the cancer incidence for a male of 25, 50 and 75 years is 0.31, 0.21 and 0.09, respectively. The LAR estimations are more suitable in health care situations involving individual patients or specific groups of patients than the health detriment based on effective dose, which represents a population average. The detriment consideration in effective dose adjusts the cancer incidence for suffering of non-lethal cancers while LAR predicts morbidity (incidence) or mortality (cancer). The advantages of these LARs are that they are gender and age specific, allowing risk estimations for specific patients or subgroups thus better representing individuals in health care

  12. Exposure to low-dose radiation and the risk of breast cancer among women with a familial or genetic predisposition: a meta-analysis

    International Nuclear Information System (INIS)

    Jansen-van der Weide, Marijke C.; Greuter, Marcel J.W.; Pijnappel, Ruud M.; Jansen, Liesbeth; Oosterwijk, Jan C.; Bock, Geertruida H. de

    2010-01-01

    Women with familial or genetic aggregation of breast cancer are offered screening outside the population screening programme. However, the possible benefit of mammography screening could be reduced due to the risk of radiation-induced tumours. A systematic search was conducted addressing the question of how low-dose radiation exposure affects breast cancer risk among high-risk women. A systematic search was conducted for articles addressing breast cancer, mammography screening, radiation and high-risk women. Effects of low-dose radiation on breast cancer risk were presented in terms of pooled odds ratios (OR). Of 127 articles found, 7 were selected for the meta-analysis. Pooled OR revealed an increased risk of breast cancer among high-risk women due to low-dose radiation exposure (OR = 1.3, 95% CI: 0.9- 1.8). Exposure before age 20 (OR = 2.0, 95% CI: 1.3-3.1) or a mean of ≥5 exposures (OR = 1.8, 95% CI: 1.1-3.0) was significantly associated with a higher radiation-induced breast cancer risk. Low-dose radiation increases breast cancer risk among high-risk women. When using low-dose radiation among high-risk women, a careful approach is needed, by means of reducing repeated exposure, avoidance of exposure at a younger age and using non-ionising screening techniques. (orig.)

  13. Negligible risk of inducing resistance in Mycobacterium tuberculosis with single-dose rifampicin as post-exposure prophylaxis for leprosy.

    Science.gov (United States)

    Mieras, Liesbeth; Anthony, Richard; van Brakel, Wim; Bratschi, Martin W; van den Broek, Jacques; Cambau, Emmanuelle; Cavaliero, Arielle; Kasang, Christa; Perera, Geethal; Reichman, Lee; Richardus, Jan Hendrik; Saunderson, Paul; Steinmann, Peter; Yew, Wing Wai

    2016-06-08

    Post-exposure prophylaxis (PEP) for leprosy is administered as one single dose of rifampicin (SDR) to the contacts of newly diagnosed leprosy patients. SDR reduces the risk of developing leprosy among contacts by around 60 % in the first 2-3 years after receiving SDR. In countries where SDR is currently being implemented under routine programme conditions in defined areas, questions were raised by health authorities and professional bodies about the possible risk of inducing rifampicin resistance among the M. tuberculosis strains circulating in these areas. This issue has not been addressed in scientific literature to date. To produce an authoritative consensus statement about the risk that SDR would induce rifampicin-resistant tuberculosis, a meeting was convened with tuberculosis (TB) and leprosy experts. The experts carefully reviewed and discussed the available evidence regarding the mechanisms and risk factors for the development of (multi) drug-resistance in M. tuberculosis with a view to the special situation of the use of SDR as PEP for leprosy. They concluded that SDR given to contacts of leprosy patients, in the absence of symptoms of active TB, poses a negligible risk of generating resistance in M. tuberculosis in individuals and at the population level. Thus, the benefits of SDR prophylaxis in reducing the risk of developing leprosy in contacts of new leprosy patients far outweigh the risks of generating drug resistance in M. tuberculosis.

  14. Assessing local patients' knowledge and awareness of radiation dose and risks associated with medical imaging: a questionnaire study

    International Nuclear Information System (INIS)

    Sin, Ho-kwan; Wong, Chun-Sing; Huang, Bingsheng; Yiu, Ka-ling; Wong, Wai-lam; Chu, Yin Ching Tiffany

    2013-01-01

    To assess the awareness of radiation dose and associated risks caused by radiological procedures among local patients. All subjects were recruited by randomly sampling the patients receiving radiological examinations. These subjects were stratified on age, sex and education. The questionnaire was in Chinese and consisted of 28 questions mostly in multiple choice/true-or-false format, divided into three sections examining demographic data, radiation knowledge/awareness and expectations. A total of 173 questionnaires were returned (83 females and 84 females; mean age of 53). Of these, 32.6% had attended college, 32.6% had completed matriculation and 24.4% secondary school. Most subjects underwent CT (75), MRI (70) and PET-CT (18). Education significantly affected the radiation knowledge (P=0.013). 60.7% and 32.7% were not aware of the radiation-free nature of MRI and USG, respectively. Respectively, 45.4% and 43.5% were of the misconception that Barium enema and Barium swallow studies do not involve radiation. Moreover, 77.6% and 87.9% were aware of the radiation-laden nature of CT and plain X-rays, respectively. Furthermore, 34% and 50%, respectively, think that they are not exposed to radiation at home and on a plane. Regarding the fatal cancer risk from CT, 17.8% chose the correct answer and 62% underestimated the risk. 32.2% correctly estimated the equivalent dose of CT in terms of number of conventional X-rays and 43.2% underestimated the dose. Most (98.2%) were told of the indication, and 42.7% were told the associated radiation dose. Patient radiation awareness is unsatisfactory. There is need to increase patient radiation awareness, and to provide them with the necessary information.

  15. Long-term high-dose oral morphine in phantom limb pain with no addiction risk

    Directory of Open Access Journals (Sweden)

    Vinod Kumar

    2015-01-01

    Full Text Available Chronic phantom limb pain (PLP is a type of neuropathic pain, which is located in the missing/amputated limb. Phantom pain is difficult to treat as the exact basis of pain mechanism is still unknown. Various methods of treatment for PLP have been described, including pharmacological (NSAIDs, opioids, antiepileptic, antidepressants and non-pharmacological (TENS, sympathectomy, deep brain stimulation and motor cortex stimulation. Opioids are used for the treatment of neuropathic pain and dose of opioid is determined based on its effect and thus there is no defined ceiling dose for opioids. We report a case where a patient receiving high-dose oral morphine for chronic cancer pain did not demonstrate signs of addiction.

  16. Public education on the health effects of low dose radiation. Why the government underestimated the risks?

    International Nuclear Information System (INIS)

    Sakiyama, Hisako

    2012-01-01

    Here the education on the health effects of radiation, which has not been taken up in the report of the National Diet of Japan Fukushima Nuclear Accident Independent Investigation Commission (NAIIC), is mentioned: The atomic power policy for the education on the health effects of radiation, the correspondence of the Ministry of Education, Culture, Sports, Science and Technology after the Fukushima accident, the side readers on the radiation, Is there the clear evidence on the correlation of dose rate under 100 mSv to diseases?, the ploblem of dose and dose-rate effectiveness factor, the fluctuation range of the death rate 0.5% from cancer, the influence and assistance of the electric enterprise union to ICRP members, etc. (M.H.)

  17. Reference computations of public dose and cancer risk from airborne releases of uranium and Class W plutonium

    International Nuclear Information System (INIS)

    Peterson, V.L.

    1995-01-01

    This report presents ''reference'' computations that can be used by safety analysts in the evaluations of the consequences of postulated atmospheric releases of radionuclides from the Rocky Flats Environmental Technology Site. These computations deal specifically with doses and health risks to the public. The radionuclides considered are Class W Plutonium, all classes of Enriched Uranium, and all classes of Depleted Uranium. (The other class of plutonium, Y, was treated in an earlier report.) In each case, one gram of the respirable material is assumed to be released at ground leveL both with and without fire. The resulting doses and health risks can be scaled to whatever amount of release is appropriate for a postulated accident being investigated. The report begins with a summary of the organ-specific stochastic risk factors appropriate for alpha radiation, which poses the main health risk of plutonium and uranium. This is followed by a summary of the atmospheric dispersion factors for unfavorable and typical weather conditions for the calculation of consequences to both the Maximum Offsite Individual and the general population within 80 km (50 miles) of the site

  18. A meta-analysis including dose-response relationship between night shift work and the risk of colorectal cancer.

    Science.gov (United States)

    Wang, Xiao; Ji, Alin; Zhu, Yi; Liang, Zhen; Wu, Jian; Li, Shiqi; Meng, Shuai; Zheng, Xiangyi; Xie, Liping

    2015-09-22

    A meta-analysis was conducted to quantitatively evaluate the correlation between night shift work and the risk of colorectal cancer. We searched for publications up to March 2015 using PubMed, Web of Science, Cochrane Library, EMBASE and the Chinese National Knowledge Infrastructure databases, and the references of the retrieved articles and relevant reviews were also checked. OR and 95% CI were used to assess the degree of the correlation between night shift work and risk of colorectal cancer via fixed- or random-effect models. A dose-response meta-analysis was performed as well. The pooled OR estimates of the included studies illustrated that night shift work was correlated with an increased risk of colorectal cancer (OR = 1.318, 95% CI 1.121-1.551). No evidence of publication bias was detected. In the dose-response analysis, the rate of colorectal cancer increased by 11% for every 5 years increased in night shift work (OR = 1.11, 95% CI 1.03-1.20). In conclusion, this meta-analysis indicated that night shift work was associated with an increased risk of colorectal cancer. Further researches should be conducted to confirm our findings and clarify the potential biological mechanisms.

  19. Radiation Dose Assesment And Risk Estimation During Extracorporeal Shock Wave Lithotripsy

    International Nuclear Information System (INIS)

    Sulieman, A.; Ibrahim, A.A.; Osman, H.; Yousef, M.

    2011-01-01

    Extracorporeal shockwave lithotripsy (ESWL) is considered the gold standard for calculi fragmentation. The aims of this study are to measure the entrance surface dose (ESD) using thermo-luminescence dosimeter (TLDs) and to estimate the probability of carcinogenesis during ESWL procedure. The study was carried out at two centers (Group A, 50 patients) and (Group B, 25 patients). The mean ESD and effective doses were 36 mGy and 34 mSv. The results show that the probability of carcinogenesis is a tiny value 100 per million patients) but the main biological effect is occurring due to the accumulative impact of radiation.

  20. Measurement of mean cardiac dose for various breast irradiation techniques and corresponding risk of major cardiovascular event.

    Directory of Open Access Journals (Sweden)

    Tomas Rodrigo Merino Lara

    2014-10-01

    Full Text Available After breast conserving surgery, early stage breast cancer patients are currently treated with a wide range of radiation techniques including whole breast irradiation (WBI, accelerated partial breast irradiation (APBI using high dose rate (HDR brachytherapy, or 3D conformal radiotherapy (3D-CRT. This study compares the mean heart’s doses for a left breast irradiated with different breast techniques.An anthropomorphic Rando phantom was modified with gelatin-based breast of different sizes and tumors located medially or laterally. The breasts were treated with WBI, 3D-CRT or HDR APBI. The heart’s mean doses were measured with Gafchromic films and controlled with optically stimulated luminescent dosimeters (OSLDs. Following the model reported by Darby (16, major cardiac were estimated assuming a linear risk increase with the mean dose to the heart of 7.4% per gray.Whole breast irradiation lead to the highest mean heart dose (2.99 Gy compared to 3D-CRT APBI, (0.51 Gy, multicatheter (1.58 Gy and balloon HDR (2.17 Gy for a medially located tumor. This translated into long-term coronary event increases of 22%, 3.8%, 11.7%, and 16% respectively. The sensitivity analysis showed that the tumor location had almost no effect on the mean heart dose for 3D-CRT APBI and a minimal impact for HDR APBI. For WBI large breast size and set-up errors lead to sharp increases of the mean heart dose. Its value reached 10.79 Gy for women with large breast and a set-up error of 1.5 cm. Such a high value could increase the risk of having long-term coronary events by 80%.Comparison among different irradiation techniques demonstrates that 3D-CRT APBI appears the safest one with less probability of having cardiovascular events in the future. A sensitivity analysis showed that WBI is the most challenging technique for patients with large breasts or when significant set-up errors are anticipated. In those cases additional heart shielding techniques are required.

  1. Risk- and cost-benefit analyses of breast screening programs derived from absorbed dose measurements in the Netherlands

    International Nuclear Information System (INIS)

    Zuur, C.; Broerse, J.J.

    1985-01-01

    Risk- and cost benefit analyses for breast screening programs are being performed, employing the risk-factors for induction of breast cancer from six extensive follow-up studies. For women of the age group above 35 years and for a risk period of 30 years after a 10-year latency period, a factor of extra cases of 20 x 10 -6 mGy -1 can be estimated. Measurements are being performed in Dutch hospitals to determine the mean absorbed tissue dose. These doses vary from 0.6 to 4.4 mGy per radiography. For a dose of 1 mGy per radiograph and yearly screening of women between 35 and 75 years, the risk of radiogenic breast cancer is about 1% of the natural incidence (85,000 per 10 6 women) in this group. A recommended frequency of screening has to be based on medical, social and financial considerations. The gain in woman years and in completely cured women is being estimated for screening with intervals of 12 instead of 24 months. The medical and social benefit is 1,520 years life-time and 69 more cases completely cured per 1,000 breast cancer patients. The financial profit of a completely cured instead of an ultimately fatal cancer can be roughly estimated at 55,000 guilders. In addition the costs per gained woman-year are about 5,000 guilders. In consequence, the extra costs of annual additional rounds of mammographic screening are balanced by the benefit. (Auth.)

  2. Radiation quality and effective dose equivalent of alpha particles from radon decay products indoors: uncertainties in risk estimation

    Energy Technology Data Exchange (ETDEWEB)

    Al-Affan, I.A. (Velindre Hospital, Whitchurch, Cardiff (United Kingdom))

    1994-01-01

    In order to make a better estimate of cancer risk due to radon the radiation quality of alpha particles emitted from the element and its daughters has been re-assessed. In particular, uncertainties in all components involved in the calculations of the effective dose E, have been investigated. This has been done in the light of the recent draft report of the ICRU on quantities and units for use in radiation protection (Allisy et al (1991) ICRU NEWS 2). On the assumption of an indoor radon concentration of 30 Bq.m[sup -3], microdose spectra have been calculated for alpha particles hitting lung cells at different depths. Then the mean quality factor Q-bar in the lung, dose equivalent H[sub T] to the lung and the effective dose have been calculated. A comparison between lung cancer risk from radon and that arising from diagnostic X rays to the chest is made. A suggestion to make the lung weighting factor w[sub T] a function of the fraction of lung cells hit is discussed. (Author).

  3. Effect of low dose of A-bomb radiation on risk of death

    International Nuclear Information System (INIS)

    Mine, Mariko; Okumura, Yutaka; Kondo, Hisayoshi; Mori, Hiroyuki

    1992-01-01

    Among about 100,000 A-bomb survivors registered at Nagasaki University School of Medicine, 290 male subjects exposed to 50-149 cGy showed significantly lower mortality from non-cancer death than age-matched unexposed males. This was deduced from the fitting of a U-shaped dose-response relationship. (author)

  4. Radiobiological research at its best. Does a low radiation dose involve risks?

    International Nuclear Information System (INIS)

    Baatout, S.; Jacquet, P.; Derradji, H.

    2011-01-01

    Radiotherapy, radiation protection, nuclear medicine, etc.: there is a growing interest in radio(bio)logy in the health care sector. The number of medical treatments with ionising radiation per year will increase even more. It is therefore increasingly important to closely monitor the possible harmful effects of low radiation doses.

  5. Professional exposure of medical workers: radiation levels, radiation risk and personal dose monitoring

    International Nuclear Information System (INIS)

    Bai Guang

    2005-01-01

    The application of radiation in the field of medicine is the most active area. Due to the rapid and strong development of intervention radiology at present near 20 years, particularly, the medical workers become a popularize group which most rapid increasing and also receiving the must high of professional exposure dose. Because, inter alias, radiation protection management nag training have not fully follow up, the aware of radioactive protection and appropriate approach have tot fully meet the development and need, the professional exposure dose received by medical workers, especially those being engaged in intervention radiology, are more higher, as well as have not yet fully receiving the complete personal dose monitoring, the medical workers become the population group which should be paid the most attention to. The writer would advice in this paper that all medical workers who being received a professional radiation exposure should pay more attention to the safety and healthy they by is strengthening radiation protection and receiving complete personal dose monitoring. (authors)

  6. Association between dietary vitamin C intake and risk of esophageal cancer: A dose-response meta-analysis.

    Science.gov (United States)

    Bo, Yacong; Lu, Yan; Zhao, Yan; Zhao, Erjiang; Yuan, Ling; Lu, Weiquan; Cui, Lingling; Lu, Quanjun

    2016-04-15

    While several epidemiological studies have investigated the association between vitamin C and risk of esophageal cancer, the results remain inconsistent. In the present study, a meta-analysis was conducted to assess the impact of dietary vitamin C intake on esophageal cancer risk. Online databases were searched up to March 29, 2015, for studies on the association between dietary vitamin C intake and esophageal cancer risk. Pooled risk ratios (RRs) or odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Dose-response analyses were performed using the method of restricted cubic splines with four knots at percentiles of 5, 35, 65 and 95% of the distribution. Publication bias was estimated using Egger's tests and funnel plots. In all, 15 articles were included in this meta-analysis, including 20 studies, containing 7063 controls and 3955 cases of esophageal cancer. By comparing the highest vs. the lowest categories of vitamin C intake, we found that vitamin C was inversely associated with the risk of esophageal cancer [overall OR = 0.58, 95% CI = 0.49-0.68, I(2) = 56%]. A linear dose-response relationship was found. With an increase in dietary vitamin C intake of 50 mg/day, the risk of esophageal cancer statistically decreased by 13% (OR = 0.87, 95% CI = 0.80-0.93, p(linearity) = 0.0002). In conclusion, our analysis suggested that the higher intake of dietary vitamin C might have a protective effect against esophageal cancer. © 2015 UICC.

  7. Dairy products consumption and risk of type 2 diabetes: systematic review and dose-response meta-analysis.

    Directory of Open Access Journals (Sweden)

    Dengfeng Gao

    Full Text Available BACKGROUND: The consumption of dairy products may influence the risk of type 2 diabetes mellitus (T2DM, but inconsistent findings have been reported. Moreover, large variation in the types of dairy intake has not yet been fully explored. METHODS AND RESULTS: We conducted a systematic review and meta-analysis to clarify the dose-response association of dairy products intake and T2DM risk. We searched PubMed, EMBASE and Scopus for studies of dairy products intake and T2DM risk published up to the end of October 2012. Random-effects models were used to estimate summary relative risk (RR statistics. Dose-response relations were evaluated using data from different dairy products in each study. We included 14 articles of cohort studies that reported RR estimates and 95% confidence intervals (95% CIs of T2DM with dairy products intake. We found an inverse linear association of consumption of total dairy products (13 studies, low-fat dairy products (8 studies, cheese (7 studies and yogurt (7 studies and risk of T2DM. The pooled RRs were 0.94 (95% CI 0.91-0.97 and 0.88 (0.84-0.93 for 200 g/day total and low-fat dairy consumption, respectively. The pooled RRs were 0.80 (0.69-0.93 and 0.91 (0.82-1.00 for 30 g/d cheese and 50 g/d yogurt consumption, respectively. We also found a nonlinear association of total and low-fat dairy intake and T2DM risk, and the inverse association appeared to be strongest within 200 g/d intake. CONCLUSION: A modest increase in daily intake of dairy products such as low fat dairy, cheese and yogurt may contribute to the prevention of T2DM, which needs confirmation in randomized controlled trials.

  8. Pregnancy after high therapeutic doses of iodine-131 in differentiated thyroid cancer: potential risks and recommendations

    International Nuclear Information System (INIS)

    Casara, D.; Rubello, D.; Saladini, G.; Piotto, A.; Pelizzo, M.R.; Girelli, M.E.; Busnardo, B.

    1993-01-01

    Seventy female patients who had been treated with high doses of iodine-131 for differented thyroid cancer (DTC) and who had a subsequent pregnancy were evaluated. The global 131 I dose ranged from 1.85 to 16.55 GBq (mean±SD=4.39±25.20 GBq). Age at first therapy ranged from 15 to 36 years (mean±SD=24.3±5.0 years) and the interval from 131 I therapy to pregnancy varied from 2 to 10 years (mean±SD=5.3±2.8 years). The estimated radiation dose to the gonads ranged from 10 to 63 cGy (mean±SD=24.0±13.5 cGy). All patients were treated with L-thyroxine at doses capable of suppressing thyroid-stimulating hormone. Seventy-three children were followed-up and seven pregnancies are still in progress. One child was affected by Fallot's trilogy and three had a low birth weight though with subsequent regular growth; the others were healthy with subsequent regular growth. No newborn with clinical or biochemical thyroid dysfunctions was found. Two spontaneous abortions during the second month of pregnancy were recorded. One of two patients in question subsequently had two healthy children. On the basis of these data, previous administration of high 131 I doses does not appear to be a valid reason for dissuading young female DTC patients from considering pregnancy. However, patients should be advised to avoid pregnancy after 131 I administration for a period sufficient to ensure complete elimination of the radionuclide and to permit confirmation of complete disease remission, i.e. at least 1 year in our opinion. (orig.)

  9. SU-F-T-452: Influence of Dose Calculation Algorithm and Heterogeneity Correction On Risk Categorization of Patients with Cardiac Implanted Electronic Devices Undergoing Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Iwai, P; Lins, L Nadler [AC Camargo Cancer Center, Sao Paulo (Brazil)

    2016-06-15

    Purpose: There is a lack of studies with significant cohort data about patients using pacemaker (PM), implanted cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT) device undergoing radiotherapy. There is no literature comparing the cumulative doses delivered to those cardiac implanted electronic devices (CIED) calculated by different algorithms neither studies comparing doses with heterogeneity correction or not. The aim of this study was to evaluate the influence of the algorithms Pencil Beam Convolution (PBC), Analytical Anisotropic Algorithm (AAA) and Acuros XB (AXB) as well as heterogeneity correction on risk categorization of patients. Methods: A retrospective analysis of 19 3DCRT or IMRT plans of 17 patients was conducted, calculating the dose delivered to CIED using three different calculation algorithms. Doses were evaluated with and without heterogeneity correction for comparison. Risk categorization of the patients was based on their CIED dependency and cumulative dose in the devices. Results: Total estimated doses at CIED calculated by AAA or AXB were higher than those calculated by PBC in 56% of the cases. In average, the doses at CIED calculated by AAA and AXB were higher than those calculated by PBC (29% and 4% higher, respectively). The maximum difference of doses calculated by each algorithm was about 1 Gy, either using heterogeneity correction or not. Values of maximum dose calculated with heterogeneity correction showed that dose at CIED was at least equal or higher in 84% of the cases with PBC, 77% with AAA and 67% with AXB than dose obtained with no heterogeneity correction. Conclusion: The dose calculation algorithm and heterogeneity correction did not change the risk categorization. Since higher estimated doses delivered to CIED do not compromise treatment precautions to be taken, it’s recommend that the most sophisticated algorithm available should be used to predict dose at the CIED using heterogeneity correction.

  10. SU-F-T-452: Influence of Dose Calculation Algorithm and Heterogeneity Correction On Risk Categorization of Patients with Cardiac Implanted Electronic Devices Undergoing Radiotherapy

    International Nuclear Information System (INIS)

    Iwai, P; Lins, L Nadler

    2016-01-01

    Purpose: There is a lack of studies with significant cohort data about patients using pacemaker (PM), implanted cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT) device undergoing radiotherapy. There is no literature comparing the cumulative doses delivered to those cardiac implanted electronic devices (CIED) calculated by different algorithms neither studies comparing doses with heterogeneity correction or not. The aim of this study was to evaluate the influence of the algorithms Pencil Beam Convolution (PBC), Analytical Anisotropic Algorithm (AAA) and Acuros XB (AXB) as well as heterogeneity correction on risk categorization of patients. Methods: A retrospective analysis of 19 3DCRT or IMRT plans of 17 patients was conducted, calculating the dose delivered to CIED using three different calculation algorithms. Doses were evaluated with and without heterogeneity correction for comparison. Risk categorization of the patients was based on their CIED dependency and cumulative dose in the devices. Results: Total estimated doses at CIED calculated by AAA or AXB were higher than those calculated by PBC in 56% of the cases. In average, the doses at CIED calculated by AAA and AXB were higher than those calculated by PBC (29% and 4% higher, respectively). The maximum difference of doses calculated by each algorithm was about 1 Gy, either using heterogeneity correction or not. Values of maximum dose calculated with heterogeneity correction showed that dose at CIED was at least equal or higher in 84% of the cases with PBC, 77% with AAA and 67% with AXB than dose obtained with no heterogeneity correction. Conclusion: The dose calculation algorithm and heterogeneity correction did not change the risk categorization. Since higher estimated doses delivered to CIED do not compromise treatment precautions to be taken, it’s recommend that the most sophisticated algorithm available should be used to predict dose at the CIED using heterogeneity correction.

  11. Risk assessment of intake of foods and soil, and air radiation dose after Fukushima Daiichi nuclear disaster

    International Nuclear Information System (INIS)

    Fujinaga, Aiichiro; Yoneda, Minoru; Ikegami, Maiko

    2012-01-01

    Risk assessment of soil contaminated with radionuclides, due to the accident of Fukushima nuclear power plant after the earthquake on March 11, 2011, was carried out by considering consumption of the contaminated food. The exposure routes were set as food intake, ingestion and inhalation of soil particles, and external radiation from the ground. As a result, exposures by ingestion, and inhalation of soil particles were negligible, and exposure by food intake and external exposure from the ground were comparatively large. This study shows air dose by the accident should be under 0.2 μSv/hour in order to control the radiation dose with consumption of food under 1 μSv/year. (author)

  12. Perception of low dose radiation risks among radiation researchers in Korea.

    Science.gov (United States)

    Seong, Ki Moon; Kwon, TaeWoo; Seo, Songwon; Lee, Dalnim; Park, Sunhoo; Jin, Young Woo; Lee, Seung-Sook

    2017-01-01

    Expert's risk evaluation of radiation exposure strongly influences the public's risk perception. Experts can inform laypersons of significant radiation information including health knowledge based on experimental data. However, some experts' radiation risk perception is often based on non-conclusive scientific evidence (i.e., radiation levels below 100 millisievert), which is currently under debate. Examining perception levels among experts is important for communication with the public since these individual's opinions have often exacerbated the public's confusion. We conducted a survey of Korean radiation researchers to investigate their perceptions of the risks associated with radiation exposure below 100 millisievert. A linear regression analysis revealed that having ≥ 11 years' research experience was a critical factor associated with radiation risk perception, which was inversely correlated with each other. Increased opportunities to understand radiation effects at perception of radiation exposure. In addition, radiation researchers conceived that more scientific evidence reducing the uncertainty for radiation effects perception of radiation exposure.

  13. Dose limits

    International Nuclear Information System (INIS)

    Fitoussi, L.

    1987-12-01

    The dose limit is defined to be the level of harmfulness which must not be exceeded, so that an activity can be exercised in a regular manner without running a risk unacceptable to man and the society. The paper examines the effects of radiation categorised into stochastic and non-stochastic. Dose limits for workers and the public are discussed

  14. Low- and high-dose radioiodine therapy for low-/intermediate-risk differentiated thyroid cancer. A preliminary clinical trial

    International Nuclear Information System (INIS)

    Qu Yuan; Huang Rui; Li Lin

    2017-01-01

    To compare the ablation results, therapeutic responses and adverse reactions between a low dose (1.1 GBq) or high dose (3.7 GBq) of 131 I in low-/intermediate-risk differentiated thyroid cancer (DTC) patients. The factors influencing the ablation result and therapeutic response were also analyzed. The researchers used a random number table to randomly assign the enrolled patients to the low-dose group or high-dose group at a 1:1 ratio, and assessment of ablation result, therapeutic response, and adverse reactions evaluated 6 ± 3 months after therapy. A total of 140 patients were enrolled in the study through October 2014-June 2015. Until February 2016, 132 patients completed the trial. 99 patients were re-examined under thyroid-stimulating hormone (TSH) stimulation 3-9 months after 131 I therapy. For the low-dose and high-dose groups, the success rates of ablation were 52.7% (29/55) and 59.1% (26/44), respectively. The ablation results did not differ significantly between the two groups (P = 0.548). One hundred and thirty two patients were re-examined 2-9 months after 131 I therapy. The low-dose group had an excellent response rate of ∼80% (53/66), an indeterminate response rate of ∼ 20% (13/66), and no cases with a biochemical incomplete response. The high-dose group had an excellent response rate of ∼85% (36/66), an indeterminate response rate of ∼11% (7/66), and a biochemical incomplete response rate of ∼4% (3/66). No significant differences in the therapeutic response were observed between the two groups (P = 0.087). Patients in stage N1b had a significantly lower success rate of ablation than those in stage N0 (P = 0.000). The success rate of ablation increased significantly with lower thyroglobulin (Tg) levels (P = 0.000). A pre-treatment Tg level was significantly associated with a higher excellent response rate (P = 0.002). Pre-treatment-stimulated Tg of 0.47 and 3.09 μg/L were identified as cut-off values for predicting the ablation result and

  15. DoReMi workshop on multidisciplinary approaches to evaluating cancer risks associated with low-dose internal contamination

    International Nuclear Information System (INIS)

    Laurier, D.; Guseva Canu, I.; Bertho, J.M.; Blanchardon, E.; Rage, E.; Baatout, S.; Bouffler, S.; Cardis, E.; Gomolka, M.; Kreuzer, M.; Hall, J.; Kesminiene, A.

    2012-01-01

    A workshop dedicated to cancer risks associated with low-dose internal contamination was organised in March 2011, in Paris, in the framework of the DoReMi (Low Dose Research towards Multidisciplinary Integration) European Network of Excellence. The aim was to identify the best epidemiological studies that provide an opportunity to develop a multidisciplinary approach to improve the evaluation of the cancer risk associated with internal contamination. This workshop provided an opportunity for in-depth discussions between researchers working in different fields including (but not limited to) epidemiology, dosimetry, biology and toxicology. Discussions confirmed the importance of research on the health effects of internal contamination. Several existing epidemiological studies provide a real possibility to improve the quantification of cancer risk associated with internal emitters. Areas for future multidisciplinary collaborations were identified, that should allow feasibility studies to be carried out in the near future. The goal of this paper is to present an overview of the presentations and discussions that took place during this workshop. (authors)

  16. High-Dose-Rate Brachytherapy Alone for Localized Prostate Cancer in Patients at Moderate or High Risk of Biochemical Recurrence

    Energy Technology Data Exchange (ETDEWEB)

    Hoskin, Peter [Cancer Centre, Mount Vernon Hospital, Northwood, Middlesex (United Kingdom); Rojas, Ana, E-mail: arc03@btconnect.com [Cancer Centre, Mount Vernon Hospital, Northwood, Middlesex (United Kingdom); Lowe, Gerry; Bryant, Linda; Ostler, Peter; Hughes, Rob; Milner, Jessica; Cladd, Helen [Cancer Centre, Mount Vernon Hospital, Northwood, Middlesex (United Kingdom)

    2012-03-15

    Purpose: To evaluate genitourinary (GU) and gastrointestinal (GI) morbidity and biochemical control of disease in patients with localized prostate adenocarcinoma treated with escalating doses per fraction of high-dose rate brachytherapy alone. Methods and Materials: A total of 197 patients were treated with 34 Gy in four fractions, 36 Gy in four fractions, 31.5 Gy in three fractions, or 26 Gy in two fractions. Median follow-up times were 60, 54, 36, and 6 months, respectively. Results: Incidence of early Grade {>=} 3 GU morbidity was 3% to 7%, and Grade 4 was 0% to 4%. During the first 12 weeks, the highest mean International Prostate Symptom Score (IPSS) value was 14, and between 6 months and 5 years it was 8. Grade 3 or 4 early GI morbidity was not observed. The 3-year actuarial rate of Grade 3 GU was 3% to 16%, and was 3% to 7% for strictures requiring surgery (4-year rate). An incidence of 1% Grade 3 GI events was seen at 3 years. Late Grade 4 GU or GI events were not observed. At 3 years, 99% of patients with intermediate-risk and 91% with high-risk disease were free of biochemical relapse (log-rank p = 0.02). Conclusions: There was no significant difference in urinary and rectal morbidity between schedules. Biochemical control of disease in patients with intermediate and high risk of relapse was good.

  17. Perception of low dose radiation risks among radiation researchers in Korea

    Science.gov (United States)

    Seo, Songwon; Lee, Dalnim; Park, Sunhoo; Jin, Young Woo; Lee, Seung-Sook

    2017-01-01

    Expert’s risk evaluation of radiation exposure strongly influences the public’s risk perception. Experts can inform laypersons of significant radiation information including health knowledge based on experimental data. However, some experts’ radiation risk perception is often based on non-conclusive scientific evidence (i.e., radiation levels below 100 millisievert), which is currently under debate. Examining perception levels among experts is important for communication with the public since these individual’s opinions have often exacerbated the public’s confusion. We conducted a survey of Korean radiation researchers to investigate their perceptions of the risks associated with radiation exposure below 100 millisievert. A linear regression analysis revealed that having ≥ 11 years’ research experience was a critical factor associated with radiation risk perception, which was inversely correlated with each other. Increased opportunities to understand radiation effects at risk perception of radiation exposure. In addition, radiation researchers conceived that more scientific evidence reducing the uncertainty for radiation effects risk perception of radiation exposure. PMID:28166286

  18. Phase I Trial of Pelvic Nodal Dose Escalation With Hypofractionated IMRT for High-Risk Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Adkison, Jarrod B.; McHaffie, Derek R.; Bentzen, Soren M.; Patel, Rakesh R.; Khuntia, Deepak [Department of Human Oncology, University of Wisconsin Carbone Cancer Center, School of Medicine and Public Health, Madison, WI (United States); Petereit, Daniel G. [Department of Radiation Oncology, John T. Vucurevich Regional Cancer Care Institute, Rapid City Regional Hospital, Rapid City, SD (United States); Hong, Theodore S.; Tome, Wolfgang [Department of Human Oncology, University of Wisconsin Carbone Cancer Center, School of Medicine and Public Health, Madison, WI (United States); Ritter, Mark A., E-mail: ritter@humonc.wisc.edu [Department of Human Oncology, University of Wisconsin Carbone Cancer Center, School of Medicine and Public Health, Madison, WI (United States)

    2012-01-01

    Purpose: Toxicity concerns have limited pelvic nodal prescriptions to doses that may be suboptimal for controlling microscopic disease. In a prospective trial, we tested whether image-guided intensity-modulated radiation therapy (IMRT) can safely deliver escalated nodal doses while treating the prostate with hypofractionated radiotherapy in 5 Vulgar-Fraction-One-Half weeks. Methods and Materials: Pelvic nodal and prostatic image-guided IMRT was delivered to 53 National Comprehensive Cancer Network (NCCN) high-risk patients to a nodal dose of 56 Gy in 2-Gy fractions with concomitant treatment of the prostate to 70 Gy in 28 fractions of 2.5 Gy, and 50 of 53 patients received androgen deprivation for a median duration of 12 months. Results: The median follow-up time was 25.4 months (range, 4.2-57.2). No early Grade 3 Radiation Therapy Oncology Group or Common Terminology Criteria for Adverse Events v.3.0 genitourinary (GU) or gastrointestinal (GI) toxicities were seen. The cumulative actuarial incidence of Grade 2 early GU toxicity (primarily alpha blocker initiation) was 38%. The rate was 32% for Grade 2 early GI toxicity. None of the dose-volume descriptors correlated with GU toxicity, and only the volume of bowel receiving {>=}30 Gy correlated with early GI toxicity (p = 0.029). Maximum late Grades 1, 2, and 3 GU toxicities were seen in 30%, 25%, and 2% of patients, respectively. Maximum late Grades 1 and 2 GI toxicities were seen in 30% and 8% (rectal bleeding requiring cautery) of patients, respectively. The estimated 3-year biochemical control (nadir + 2) was 81.2 {+-} 6.6%. No patient manifested pelvic nodal failure, whereas 2 experienced paraaortic nodal failure outside the field. The six other clinical failures were distant only. Conclusions: Pelvic IMRT nodal dose escalation to 56 Gy was delivered concurrently with 70 Gy of hypofractionated prostate radiotherapy in a convenient, resource-efficient, and well-tolerated 28-fraction schedule. Pelvic nodal dose

  19. Methods for Estimation of Radiation Risk in Epidemiological Studies Accounting for Classical and Berkson Errors in Doses

    KAUST Repository

    Kukush, Alexander

    2011-01-16

    With a binary response Y, the dose-response model under consideration is logistic in flavor with pr(Y=1 | D) = R (1+R)(-1), R = λ(0) + EAR D, where λ(0) is the baseline incidence rate and EAR is the excess absolute risk per gray. The calculated thyroid dose of a person i is expressed as Dimes=fiQi(mes)/Mi(mes). Here, Qi(mes) is the measured content of radioiodine in the thyroid gland of person i at time t(mes), Mi(mes) is the estimate of the thyroid mass, and f(i) is the normalizing multiplier. The Q(i) and M(i) are measured with multiplicative errors Vi(Q) and ViM, so that Qi(mes)=Qi(tr)Vi(Q) (this is classical measurement error model) and Mi(tr)=Mi(mes)Vi(M) (this is Berkson measurement error model). Here, Qi(tr) is the true content of radioactivity in the thyroid gland, and Mi(tr) is the true value of the thyroid mass. The error in f(i) is much smaller than the errors in ( Qi(mes), Mi(mes)) and ignored in the analysis. By means of Parametric Full Maximum Likelihood and Regression Calibration (under the assumption that the data set of true doses has lognormal distribution), Nonparametric Full Maximum Likelihood, Nonparametric Regression Calibration, and by properly tuned SIMEX method we study the influence of measurement errors in thyroid dose on the estimates of λ(0) and EAR. The simulation study is presented based on a real sample from the epidemiological studies. The doses were reconstructed in the framework of the Ukrainian-American project on the investigation of Post-Chernobyl thyroid cancers in Ukraine, and the underlying subpolulation was artificially enlarged in order to increase the statistical power. The true risk parameters were given by the values to earlier epidemiological studies, and then the binary response was simulated according to the dose-response model.

  20. Methods for estimation of radiation risk in epidemiological studies accounting for classical and Berkson errors in doses.

    Science.gov (United States)

    Kukush, Alexander; Shklyar, Sergiy; Masiuk, Sergii; Likhtarov, Illya; Kovgan, Lina; Carroll, Raymond J; Bouville, Andre

    2011-02-16

    With a binary response Y, the dose-response model under consideration is logistic in flavor with pr(Y=1 | D) = R (1+R)(-1), R = λ(0) + EAR D, where λ(0) is the baseline incidence rate and EAR is the excess absolute risk per gray. The calculated thyroid dose of a person i is expressed as Dimes=fiQi(mes)/Mi(mes). Here, Qi(mes) is the measured content of radioiodine in the thyroid gland of person i at time t(mes), Mi(mes) is the estimate of the thyroid mass, and f(i) is the normalizing multiplier. The Q(i) and M(i) are measured with multiplicative errors Vi(Q) and ViM, so that Qi(mes)=Qi(tr)Vi(Q) (this is classical measurement error model) and Mi(tr)=Mi(mes)Vi(M) (this is Berkson measurement error model). Here, Qi(tr) is the true content of radioactivity in the thyroid gland, and Mi(tr) is the true value of the thyroid mass. The error in f(i) is much smaller than the errors in ( Qi(mes), Mi(mes)) and ignored in the analysis. By means of Parametric Full Maximum Likelihood and Regression Calibration (under the assumption that the data set of true doses has lognormal distribution), Nonparametric Full Maximum Likelihood, Nonparametric Regression Calibration, and by properly tuned SIMEX method we study the influence of measurement errors in thyroid dose on the estimates of λ(0) and EAR. The simulation study is presented based on a real sample from the epidemiological studies. The doses were reconstructed in the framework of the Ukrainian-American project on the investigation of Post-Chernobyl thyroid cancers in Ukraine, and the underlying subpolulation was artificially enlarged in order to increase the statistical power. The true risk parameters were given by the values to earlier epidemiological studies, and then the binary response was simulated according to the dose-response model.

  1. Reduction of the estimated radiation dose and associated patient risk with prospective ECG-gated 256-slice CT coronary angiography

    International Nuclear Information System (INIS)

    Efstathopoulos, E P; Kelekis, N L; Pantos, I; Brountzos, E; Argentos, S; Grebac, J; Ziaka, D; Seimenis, I; Katritsis, D G

    2009-01-01

    Computed tomography (CT) coronary angiography has been widely used since the introduction of 64-slice scanners and dual-source CT technology, but high radiation doses have been reported. Prospective ECG-gating using a 'step-and-shoot' axial scanning protocol has been shown to reduce radiation exposure effectively while maintaining diagnostic accuracy. 256-slice scanners with 80 mm detector coverage have been currently introduced into practice, but their impact on radiation exposure has not been adequately studied. The aim of this study was to assess radiation doses associated with CT coronary angiography using a 256-slice CT scanner. Radiation doses were estimated for 25 patients scanned with either prospective or retrospective ECG-gating. Image quality was assessed objectively in terms of mean CT attenuation at selected regions of interest on axial coronary images and subjectively by coronary segment quality scoring. It was found that radiation doses associated with prospective ECG-gating were significantly lower than retrospective ECG-gating (3.2 ± 0.6 mSv versus 13.4 ± 2.7 mSv). Consequently, the radiogenic fatal cancer risk for the patient is much lower with prospective gating (0.0176% versus 0.0737%). No statistically significant differences in image quality were observed between the two scanning protocols for both objective and subjective quality assessments. Therefore, prospective ECG-gating using a 'step-and-shoot' protocol that covers the cardiac anatomy in two axial acquisitions effectively reduces radiation doses in 256-slice CT coronary angiography without compromising image quality.

  2. Radiotherapy and risk of implantable cardioverter-defibrillator malfunctions: experimental data from direct exposure at increasing doses.

    Science.gov (United States)

    Zecchin, Massimo; Artico, Jessica; Morea, Gaetano; Severgnini, Mara; Bianco, Elisabetta; De Luca, Antonio; Fantasia, Anna Zorzin; Salvatore, Luca; Milan, Vittorino; Lucarelli, Matteo; Dissegna, Roberta; Cannatà, Antonio; Sinagra, Gianfranco

    2018-04-01

    During radiotherapy, in patients with implantable cardioverter-defibrillators (ICDs) malfunctions are considered more likely if doses more than 2 Gy reach the ICD site; however, most malfunctions occur with high-energy (>10 MV) radiations, and the risk is less defined using 6-MV linear accelerators. The purpose of the study is to experimentally evaluate the occurrence of malfunctions in ICDs radiated with a 6-MV linear accelerator at increasing photon doses. Thirty-two ICDs from all manufacturers (31 explanted and one demo) were evaluated; all devices with a sufficient battery charge underwent multiple radiations with a 6-MV photon beam reaching a cumulative dose at ICD site of 0.5, 1, 2, 3, 5 and 10 Gy and interrogated after every session. All antitachycardia therapies were left enabled; two ICDs were connected to a rhythm simulator (one simulating a complete atrioventricular block without ventricular activity) and visually monitored by external ECG and the ICD programmer during radiation. Thirteen ICDs were excluded before radiation because of battery depletion; after radiation up to the cumulative dose at the cardiac implantable electronic device site of 10 Gy, in the remaining 19 devices, programmation and battery charge remained unchanged and no switch to safety mode was observed; oversensing, pacing inhibition or inappropriate antitachycardia therapy were neither recorded nor visually observed during radiation. With a low-energy accelerator, neither malfunctions nor electromagnetic interferences were detected radiating the ICDs at doses usually reaching the ICD pocket during radiotherapy sessions. In this context, magnet application to avoid oversensing and inappropriate therapy seems, therefore, useless.

  3. Radiotherapy after high-dose chemotherapy and peripheral blood stem cell support in high-risk breast cancer

    International Nuclear Information System (INIS)

    Hoeller, Ulrike; Heide, Juergen; Kroeger, Nicolaus; Krueger, William; Jaenicke, Fritz; Alberti, Winfried

    2002-01-01

    Purpose: To assess the toxicity and efficacy of radiotherapy with respect to locoregional control after adjuvant high-dose chemotherapy for patients with breast cancer. At first, radiotherapy was withheld because of toxicity concerns, but it was introduced in 1995 because of reported high locoregional relapse rates. Methods and Materials: Between 1992 and 1998, 40 patients with Stage II-III high-risk breast cancer received adjuvant high-dose chemotherapy consisting of thiotepa, mitoxantrone, and cyclophosphamide and peripheral blood stem cell support after four cycles of induction chemotherapy. The chest wall or breast, as well as the supraclavicular nodes, were irradiated with electrons and photons to a median dose of 50.4 Gy in 20 patients. Six additional patients received only supraclavicular irradiation to a median dose of 50.4 Gy. Acute toxicity was scored clinically. Pulmonary function tests were performed in 14 irradiated patients before high-dose chemotherapy and 1.1-4.4 years (median 1.6) after irradiation. The median follow-up time of living patients was 33 vs. 67 months in irradiated (n=26) and nonirradiated (n=14) patients, respectively. Results: G2 and G3 hematologic toxicity occurred in 1 patient each. No clinical pneumonitis or clinical impairment of lung function was observed. After 1-2 years, the lung function tests showed only minor changes in 4 patients. The 3-year locoregional control rate was 92% in the irradiated patients vs. 58% in the nonirradiated patients (p=0.049, actuarial analysis). Conclusion: In this series, adjuvant radiotherapy after adjuvant chemotherapy for breast cancer appeared well tolerated, with improved local regional control and without significant side effects. Longer follow-up and more patient accrual, as well as Phase III trials, are necessary for confirmation

  4. Summary of literature review of risk communication: Hanford Environmental Dose Reconstruction Project

    International Nuclear Information System (INIS)

    Byram, S.J.

    1991-05-01

    The Hanford Environmental Dose Reconstruction (HEDR) Project will estimate radiation exposures people may have received from radioactive materials released during past operations at the Department of Energy's Hanford Site near Richland, Washington. The project is being conducted by Pacific Northwest Laboratory (PNL) under the direction of an independent Technical Steering Panel (TSP). The Centers for Disease Control (CDC) will use HEDR dose estimates in studies to investigate a potential link between thyroid disease and historical Hanford emissions. The HEDR Project was initiated to address public concerns about the possible health impacts from past releases of radioactive materials from Hanford. The TSP recognized early in the project that special mechanisms would be required to communicate effectively to the many different concerned audiences. To identify and develop these mechanisms, the TSP issued Directive 89-7 to PNL in May 1989. The TSP directed PNL to examine methods to communicate the causes and effects of uncertainties in the dose estimates. A literature review was conducted as the first activity in response to the TSP's directive. This report presents the results of the literature review. The objective of the literature review was to identify ''key principles'' that could be applied to develop communications strategies for the project. 26 refs., 6 figs

  5. Paediatrician awareness of radiation dose and inherent risks in chest imaging studies--a questionnaire study.

    Science.gov (United States)

    Heyer, Christoph M; Hansmann, Jan; Peters, Sören A; Lemburg, Stefan P

    2010-11-01

    To assess paediatricians' knowledge regarding radiation exposure of chest imaging. German paediatricians were surveyed using a questionnaire. Participants were asked to estimate effective dose (ED) of radiographs (CR) and computed tomography (CT). Further questions included dose-saving of paediatric CT-protocols, ALARA principle, and awareness of the link between radiation and cancer development. Length and type of occupation and amount of ordered procedures were evaluated. 137 paediatricians participated with 59% and 39% correctly estimating ED of an adult (0.01-0.1mSv) and newborn CR (0.01-0.1mSv), respectively. ED of an adult chest CT (1-10mSv) was underestimated by 28%, whereas ED of cardiac CT (10-100mSv) was underestimated by 54%. 35% of participants correctly estimated ED of a chest CT in an infant (10-100mSv) which was underestimated by 56%. Neither length nor type of occupation showed significant impact on dose estimations. 14% of paediatricians stated that MRI causes radiation, whereas 4% correctly estimated the potential of paediatric CT-protocols. 15% were familiar with the ALARA principle and 26% were aware of a publication concerning radiation and malignancy. Paediatricians demonstrated an increased level of awareness compared to previous surveys. However, estimation of ED of CT remained difficult. Increased information transfer and education seem pressing in the light of increasing radiological examinations. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  6. Clinical implementation of dose-volume histogram predictions for organs-at-risk in IMRT planning

    International Nuclear Information System (INIS)

    Moore, K L; Appenzoller, L M; Tan, J; Michalski, J M; Thorstad, W L; Mutic, S

    2014-01-01

    True quality control (QC) of the planning process requires quantitative assessments of treatment plan quality itself, and QC in IMRT has been stymied by intra-patient anatomical variability and inherently complex three-dimensional dose distributions. In this work we describe the development of an automated system to reduce clinical IMRT planning variability and improve plan quality using mathematical models that predict achievable OAR DVHs based on individual patient anatomy. These models rely on the correlation of expected dose to the minimum distance from a voxel to the PTV surface, whereby a three-parameter probability distribution function (PDF) was used to model iso-distance OAR subvolume dose distributions. DVH models were obtained by fitting the evolution of the PDF with distance. Initial validation on clinical cohorts of 40 prostate and 24 head-and-neck plans demonstrated highly accurate model-based predictions for achievable DVHs in rectum, bladder, and parotid glands. By quantifying the integrated difference between candidate DVHs and predicted DVHs, the models correctly identified plans with under-spared OARs, validated by replanning all cases and correlating any realized improvements against the predicted gains. Clinical implementation of these predictive models was demonstrated in the PINNACLE treatment planning system by use of existing margin expansion utilities and the scripting functionality inherent to the system. To maintain independence from specific planning software, a system was developed in MATLAB to directly process DICOM-RT data. Both model training and patient-specific analyses were demonstrated with significant computational accelerations from parallelization.

  7. [Doses to organs at risk in conformational and stereotactic body radiation therapy: Liver].

    Science.gov (United States)

    Debbi, K; Janoray, G; Scher, N; Deutsch, É; Mornex, F

    2017-10-01

    The liver is an essential organ that ensures many vital functions such as metabolism of bilirubin, glucose, lipids, synthesis of coagulation factors, destruction of many toxins, etc. The hepatic parenchyma can be irradiated during the management of digestive tumors, right basithoracic, esophagus, abdomen in toto or TBI. In addition, radiotherapy of the hepatic area, which is mainly stereotactic, now occupies a central place in the management of primary or secondary hepatic tumors. Irradiation of the whole liver, or part of it, may be complicated by radiation-induced hepatitis. It is therefore necessary to respect strict dosimetric constraints both in stereotactic and in conformational irradiation in order to limit the undesired irradiation of the hepatic parenchyma which may vary according to the treatment techniques, the basic hepatic function or the lesion size. The liver is an organ with a parallel architecture, so the average tolerable dose in the whole liver should be considered rather than the maximum tolerable dose at one point. The purpose of this article is to propose a development of dose recommendations during conformation or stereotactic radiotherapy of the liver. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  8. Individualized toxicity-titrated 6-mercaptopurine increments during high-dose methotrexate consolidation treatment of lower risk childhood acute lymphoblastic leukemia

    DEFF Research Database (Denmark)

    Frandsen, Thomas Leth; Abrahamsson, Jonas; Lausen, Birgitte Frederiksen

    2011-01-01

    This study explored the feasibility and toxicity of individualized toxicity-titrated 6-mercaptopurine (6MP) dose increments during post-remission treatment with High-dose methotrexate (HDM) (5000 mg/m2, ×3) in 38 patients with Childhood (ALL). Patients were increased in steps of 25 mg 6MP/m2 per...... the remaining patients (P = 0·03). This study shows individualized toxicity-titrated 6MP dosing during consolidation is feasible without increased risk of toxicity....

  9. Risk of Injection-Site Abscess among Infants Receiving a Preservative-Free, Two-Dose Vial Formulation of Pneumococcal Conjugate Vaccine in Kenya

    Science.gov (United States)

    Burton, Deron C.; Bigogo, Godfrey M.; Audi, Allan O.; Williamson, John; Munge, Kenneth; Wafula, Jackline; Ouma, Dominic; Khagayi, Sammy; Mugoya, Isaac; Mburu, James; Muema, Shadrack; Bauni, Evasius; Bwanaali, Tahreni; Feikin, Daniel R.; Ochieng, Peter M.; Mogeni, Ondari D.; Otieno, George A.; Olack, Beatrice; Kamau, Tatu; Van Dyke, Melissa K.; Chen, Robert; Farrington, Paddy; Montgomery, Joel M.; Breiman, Robert F.; Scott, J. Anthony G.; Laserson, Kayla F.

    2015-01-01

    There is a theoretical risk of adverse events following immunization with a preservative-free, 2-dose vial formulation of 10-valent-pneumococcal conjugate vaccine (PCV10). We set out to measure this risk. Four population-based surveillance sites in Kenya (total annual birth cohort of 11,500 infants) were used to conduct a 2-year post-introduction vaccine safety study of PCV10. Injection-site abscesses occurring within 7 days following vaccine administration were clinically diagnosed in all study sites (passive facility-based surveillance) and, also, detected by caregiver-reported symptoms of swelling plus discharge in two sites (active household-based surveillance). Abscess risk was expressed as the number of abscesses per 100,000 injections and was compared for the second vs first vial dose of PCV10 and for PCV10 vs pentavalent vaccine (comparator). A total of 58,288 PCV10 injections were recorded, including 24,054 and 19,702 identified as first and second vial doses, respectively (14,532 unknown vial dose). The risk ratio for abscess following injection with the second (41 per 100,000) vs first (33 per 100,000) vial dose of PCV10 was 1.22 (95% confidence interval [CI] 0.37–4.06). The comparator vaccine was changed from a 2-dose to 10-dose presentation midway through the study. The matched odds ratios for abscess following PCV10 were 1.00 (95% CI 0.12–8.56) and 0.27 (95% CI 0.14–0.54) when compared to the 2-dose and 10-dose pentavalent vaccine presentations, respectively. In Kenya immunization with PCV10 was not associated with an increased risk of injection site abscess, providing confidence that the vaccine may be safely used in Africa. The relatively higher risk of abscess following the 10-dose presentation of pentavalent vaccine merits further study. PMID:26509274

  10. High dose rate brachytherapy for carcinoma of the cervix: risk factors for late rectal complications

    International Nuclear Information System (INIS)

    Uno, Takashi; Itami, Jun; Aruga, Moriyo; Kotaka, Kikuo; Fujimoto, Hajime; Minoura, Shigeki

    1996-01-01

    Purpose/Objective: To determine the incidence of late rectal complications in patients treated with high dose rate brachytherapy for FIGO stage IIB, IIIB carcinoma of the uterine cervix, and to evaluate the treatment factors associated with an increased probability of treatment complications. Materials and Methods: Records of 100 patients with FIGO IIB or IIIB cervical carcinoma treated with definitive irradiation using high dose rate intracavitary brachytherapy (HDR-ICR) between 1977 and 1994 were retrospectively reviewed. For each HDR-ICR session, 6 Gy isodose volume was reconstructed three dimensionally and the following three parameters were determined to represent this isodose volume, length (L); maximum longitudinal distance of 6 Gy isodose area in an oblique frontal plane containing the intrauterine applicator, width (W); maximum width of 6 Gy isodose area in the same plane, height (H); maximum dimension of 6 Gy isodose area perpendicular to the intrauterine applicator determined in the oblique sagittal plane. Point P/Q (2 cm ventral/dorsal from the proximal retention point of the intrauterine source) and point R/S (2 cm ventral/dorsal from the midpoint of the ovoid sources) were also defined retrospectively and HDR-ICR dose at these points were calculated. Statistical analyses were performed to determine the treatment factors predictive of late rectal complications. Results: The 5-year cumulative cause-specific disease-free survival rate was 50% for all, 74% for Stage IIB, and 38% for Stage IIIB, with a significant difference between two FIGO Stages (p=0.0004). Of patients treated for both stages, 30% and 36% had experienced moderate to severe (Grade 2-4) complications at 3 and 5 years, respectively. Average H value (p=0.013) and cumulative point S dose by HDR-ICR (p=0.020) were significantly correlated with the incidence of late rectal complications (Student's t-test), whereas these factors did not significantly affect the probability of pelvic control. No

  11. Low-dose dexamethasone during arthroplasty: What do we know about the risks?

    NARCIS (Netherlands)

    Wegener, Jessica T.; Kraal, Tim; Stevens, Markus F.; Hollmann, Markus W.; Kerkhoffs, Gino M. M. J.; Haverkamp, Daniël

    2016-01-01

    Dexamethasone is commonly applied during arthroplasty to control post-operative nausea and vomiting (PONV). However, conflicting views of orthopaedic surgeons and anaesthesiologists regarding the use of dexamethasone raise questions about risks of impaired wound healing and surgical site infections

  12. Infradiaphragmatic irradiation and high procarbazine doses increase colorectal cancer risk in Hodgkin lymphoma survivors

    DEFF Research Database (Denmark)

    van Eggermond, Anna M; Schaapveld, Michael; Janus, Cécile Pm

    2017-01-01

    incidence ratios (SIR) was 2.4-fold increased (95% confidence interval (95%CI) 1.8-3.2), leading to 5.7 excess cases per 10 000 patient-years. Risk was still increased 30 years after HL treatment (SIR: 2.8; 95%CI: 1.6-4.6). The highest (SIR: 6.5, 95%CI: 3.3-11.3) was seen for transverse colon cancer (15......BACKGROUND: Hodgkin lymphoma (HL) survivors are at increased risk of second malignancies, but few studies have assessed colorectal cancer (CRC) risk after HL treatment. We assessed long-term, subsite-specific CRC risk associated with specific radiation fields and chemotherapy regimens. METHODS...... a hazard ratio of 6.8 (95%CI: 3.0-15.6) compared with patients receiving neither treatment, which is significantly higher than an additive joint effect (Padditivity=0.004). CONCLUSIONS: Colorectal cancer surveillance should be considered for HL survivors who received Infradiaphragmatic radiotherapy...

  13. Mutation frequencies in male mice and the estimation of genetic hazards of radiation in men: (specific-locus mutations/dose-rate effect/doubling dose/risk estimation)

    International Nuclear Information System (INIS)

    Russell, W.L.; Kelly, E.M.

    1982-01-01

    Estimation of the genetic hazards of ionizing radiation in men is based largely on the frequency of transmitted specific-locus mutations induced in mouse spermatogonial stem cells at low radiation dose rates. The publication of new data on this subject has permitted a fresh review of all the information available. The data continue to show no discrepancy from the interpretation that, although mutation frequency decreases markedly as dose rate is decreased from 90 to 0.8 R/min (1 R = 2.6 X 10 -4 coulombs/kg) there seems to be no further change below 0.8 R/min over the range from that dose rate to 0.0007 R/min. Simple mathematical models are used to compute: (a) a maximum likelihood estimate of the induced mutation frequency at the low dose rates, and (b) a maximum likelihood estimate of the ratio of this to the mutation frequency at high dose rates in the range of 72 to 90 R/min. In the application of these results to the estimation of genetic hazards of radiation in man, the former value can be used to calculate a doubling dose - i.e., the dose of radiation that induces a mutation frequency equal to the spontaneous frequency. The doubling dose based on the low-dose-rate data compiled here is 110 R. The ratio of the mutation frequency at low dose rate to that at high dose rate is useful when it becomes necessary to extrapolate from experimental determinations, or from human data, at high dose rates to the expected risk at low dose rates. The ratio derived from the present analysis is 0.33

  14. A comparison of mantle versus involved-field radiotherapy for Hodgkin's lymphoma: reduction in normal tissue dose and second cancer risk

    International Nuclear Information System (INIS)

    Koh, Eng-Siew; Paul, Narinder; Hodgson, David C; Tran, Tu Huan; Heydarian, Mostafa; Sachs, Rainer K; Tsang, Richard W; Brenner, David J; Pintilie, Melania; Xu, Tony; Chung, June

    2007-01-01

    Hodgkin's lymphoma (HL) survivors who undergo radiotherapy experience increased risks of second cancers (SC) and cardiac sequelae. To reduce such risks, extended-field radiotherapy (RT) for HL has largely been replaced by involved field radiotherapy (IFRT). While it has generally been assumed that IFRT will reduce SC risks, there are few data that quantify the reduction in dose to normal tissues associated with modern RT practice for patients with mediastinal HL, and no estimates of the expected reduction in SC risk. Organ-specific dose-volume histograms (DVH) were generated for 41 patients receiving 35 Gy mantle RT, 35 Gy IFRT, or 20 Gy IFRT, and integrated organ mean doses were compared for the three protocols. Organ-specific SC risk estimates were estimated using a dosimetric risk-modeling approach, analyzing DVH data with quantitative, mechanistic models of radiation-induced cancer. Dose reductions resulted in corresponding reductions in predicted excess relative risks (ERR) for SC induction. Moving from 35 Gy mantle RT to 35 Gy IFRT reduces predicted ERR for female breast and lung cancer by approximately 65%, and for male lung cancer by approximately 35%; moving from 35 Gy IFRT to 20 Gy IFRT reduces predicted ERRs approximately 40% more. The median reduction in integral dose to the whole heart with the transition to 35 Gy IFRT was 35%, with a smaller (2%) reduction in dose to proximal coronary arteries. There was no significant reduction in thyroid dose. The significant decreases estimated for radiation-induced SC risks associated with modern IFRT provide strong support for the use of IFRT to reduce the late effects of treatment. The approach employed here can provide new insight into the risks associated with contemporary IFRT for HL, and may facilitate the counseling of patients regarding the risks associated with this treatment

  15. New use of low-dose aspirin and risk of colorectal cancer by stage at diagnosis: a nested case-control study in UK general practice.

    Science.gov (United States)

    García Rodríguez, Luis A; Soriano-Gabarró, Montse; Bromley, Susan; Lanas, Angel; Cea Soriano, Lucía

    2017-09-07

    Evidence from clinical trial populations suggests low-dose aspirin reduces the risk of colorectal cancer (CRC). Part of this reduction in risk might be due to protection against metastatic disease. We investigated the risk of CRC among new-users of low-dose aspirin (75-300 mg), including risk by stage at diagnosis. Using The Health Improvement Network, we conducted a cohort study with nested case-control analysis. Two cohorts (N = 170,336 each) aged 40-89 years from 2000 to 2009 and free of cancer were identified: i) new-users of low-dose aspirin, ii) non-users of low-dose aspirin, at start of follow-up, matched by age, sex and previous primary care practitioner visits. Patients were followed for up to 12 years to identify incident CRC. 10,000 frequency-matched controls were selected by incidence density sampling where the odds ratio is an unbiased estimator of the incidence rate ratio (RR). RRs with 95% confidence intervals were calculated. Low-dose aspirin use was classified 'as-treated' independent from baseline exposure status to account for changes in exposure during follow-up. Current users of low-dose aspirin (use on the index date or in the previous 90 days) had a significantly reduced risk of CRC, RR 0.66 (95% CI 0.60-0.74). The reduction in risk was apparent across all age groups, and was unrelated to dose, indication, gender, CRC location or case-fatality status. Reduced risks occurred throughout treatment duration and with all low-dose aspirin doses. RRs by aspirin indication were 0.71 (0·63-0·79) and 0.60 (0.53-0.68) for primary and secondary cardiovascular protection, respectively. Among cases with staging information (n = 1421), RRs for current use of low-dose aspirin were 0.94 (0.66-1.33) for Dukes Stage A CRC, 0.54 (0.42-0.68) for Dukes B, 0.71 (0.56-0.91) for Dukes C, and 0.60 (0.48-0.74) for Dukes D. After 5 years' therapy, the RR for Dukes Stage A CRC was 0.53 (0.24-1.19). Patients starting low-dose aspirin therapy have a reduced

  16. Delayed Dosing of Oral Rotavirus Vaccine Demonstrates Decreased Risk of Rotavirus Gastroenteritis Associated With Serum Zinc: A Randomized Controlled Trial.

    Science.gov (United States)

    Colgate, E Ross; Haque, Rashidul; Dickson, Dorothy M; Carmolli, Marya P; Mychaleckyj, Josyf C; Nayak, Uma; Qadri, Firdausi; Alam, Masud; Walsh, Mary Claire; Diehl, Sean A; Zaman, K; Petri, William A; Kirkpatrick, Beth D

    2016-09-01

    Rotavirus is the world's leading cause of childhood diarrheal death. Despite successes, oral rotavirus vaccines are less effective in developing countries. In an urban slum of Dhaka, we performed active diarrhea surveillance to evaluate monovalent G1P[8] rotavirus vaccine (RV1) efficacy and understand variables contributing to risk of rotavirus diarrhea (RVD). We performed a randomized controlled trial of monovalent oral rotavirus vaccine (RV1). Seven hundred healthy infants received RV1 or no RV1 (1:1) using delayed dosing (10 and 17 weeks) and were followed for 1 year. Intensive diarrhea surveillance was performed. The primary outcome was ≥1 episode of RVD. Nutritional, socioeconomic, and immunologic factors were assessed by logistic regression best-subsets analysis for association with risk of RVD and interactions with vaccine arm. Incidence of all RVD was 38.3 cases per 100 person-years. Per-protocol RV1 efficacy was 73.5% (95% confidence interval [CI], 45.8%-87.0%) against severe RVD and 51% (95% CI, 33.8%-63.7%) against all RVD. Serum zinc level (odds ratio [OR], 0.77; P = .002) and lack of rotavirus immunoglobulin A (IgA) seroconversion (OR, 1.95; P = .018) were associated with risk of RVD, independent of vaccination status. Water treatment and exclusive breastfeeding were of borderline significance. Factors not associated with RVD included height for age at 10 weeks, vitamin D, retinol binding protein, maternal education, household income, and sex. In an urban slum with high incidence of RVD, the efficacy of RV1 against severe RVD was higher than anticipated in the setting of delayed dosing. Lower serum zinc level and lack of IgA seroconversion were associated with increased risk of RVD independent of vaccination. NCT01375647. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  17. Dose reconstruction for birds species exposed to ionizing radiations highlights risk for species reproducing in the Fukushima Prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Adam-Guillermin, C.; Beaugelin-Seiller, K.; Sternalski, A.; Bonzom, J.M.; Garnier-Laplace, J. [Institut de Radioprotection et de Surete Nucleaire - IRSN (France); Brown, J.E. [Norwegian Radiation Protection Authority - NRPA (Norway); Giraudeau, M. [Arizona state university (United States)

    2014-07-01

    The damaged Fukushima Daiichi nuclear power station (FDNPS) in Japan following the earthquake in March 2011 led to a massive release of radioactive isotopes into the environment. The atmospheric releases have created a footprint of radioactive contamination in the terrestrial ecosystems around the site, with a hot spot area that extends up to 80-km northwest. Despite some data are available on medium and biota contamination, there is still a lack of knowledge on possible ecological consequences due to the complexity of the exposure situation. Few papers were published using data observed in situ, reporting a reduction of bird and invertebrate abundance (Moeller et al., 2012, 2013) and morphological effects in butterflies (Hiyama et al., 2012). But as for any contaminant, the biological effects are dependent on the dose received, and an accurate dose estimation is needed to be able to correctly predict ecological risk. An early study has published preliminary radiological dose reconstruction from Fukushima wildlife signaling potential ecological consequences, but without using any quantitative data relating to biological samples (Garnier-Laplace et al., 2011). In this general framework, the work presented here aims at refining the first assessment conducted to evaluate possible consequences of the FDNPS radioactive releases, focusing on some bird species, studied in Fukushima but also in Chernobyl. Public data available on bird and soil contamination were used to check the bird contamination model used, showing that radioactive contamination predictions were within the range of variation of measured data. This model was then applied to estimate doses in bird species living in the Fukushima prefecture and known to reproduce during the period just after the nuclear power plant accident, based on ecological maps established for Japan. The influence of life stages and species ecological characteristics was taken into account on the dose estimates. The heterogeneity of

  18. High-dose thalidomide increases the risk of peripheral neuropathy in the treatment of ankylosing spondylitis

    Directory of Open Access Journals (Sweden)

    Hong-xia Xue

    2015-01-01

    Full Text Available Thalidomide is an effective drug for the treatment of ankylosing spondylitis but might induce peripheral neuropathy. This major adverse reaction has attracted much concern. The current study aimed to observe the incidence of thalidomide-induced peripheral neuropathy among ankylosing spondylitis patients for 1 year after treatment. In this study, 207 ankylosing spondylitis cases received thalidomide treatment, while 116 ankylosing spondylitis cases received other treatments. Results showed that the incidence of thalidomide-induced peripheral neuropathy in the thalidomide group was higher than that in the non-thalidomide group. There was no significant difference in the incidence of neuropathy between the < 6 months medication and ≥ 6 months medication groups. There were no differences in the mean age, gender, or daily dose between the two groups. The incidence of peripheral neuropathy among patients receiving 25, 50, 75, or 100 mg thalidomide per day was 4.6%, 8.5%, 17.1%, 21.7%, respectively. The incidence was significantly different between the groups receiving 25 mg and 100 mg thalidomide. In conclusion, thalidomide can induce peripheral neuropathy within 1 year after treatment of ankylosing spondylitis; however, age and gender have no obvious impact on the incidence of peripheral neuropathy. The incidence of peripheral neuropathy is associated with increasing daily doses of thalidomide.

  19. Dose-to-risk conversion factors for low-level tritium exposures

    International Nuclear Information System (INIS)

    Straume, T.

    1992-01-01

    During the past decade, a large number of radiobiological studies have become available for tritium-many of them focusing on the relative biological effectiveness (RBE) of tritium beta rays. These and previous studies indicate that tritium in body water produces the same spectrum of radiogenic effects, e.g., cancer, genetic effects, developmental abnormalities, and reproductive effects, observed following whole-body exposure to penetrating radiations such as gamma rays and x rays. The only significant difference in biological response between tritium beta-rays and the other common low linear-energy transfer (LET) radiations, such as gamma rays and x rays, appears to be the greater biological effectiveness of tritium beta rays. For example, tritium in the oxide form (HTO) is about 2 to 3 times more effective at low doses or low dose rates than gamma rays from 137 Cs or 60 CO (Straume, 1991). When tritium is bound to organic molecules, RBE values may be somewhat larger than those for HTO. It is now clear from the wealth of tritium data available that RBEs for tritium beta rays are higher than the quality factor of unity generally used in radiation protection

  20. The Cancer of the Prostate Risk Assessment (CAPRA) score predicts biochemical recurrence in intermediate-risk prostate cancer treated with external beam radiotherapy (EBRT) dose escalation or low-dose rate (LDR) brachytherapy.

    Science.gov (United States)

    Krishnan, Vimal; Delouya, Guila; Bahary, Jean-Paul; Larrivée, Sandra; Taussky, Daniel

    2014-12-01

    To study the prognostic value of the University of California, San Francisco Cancer of the Prostate Risk Assessment (CAPRA) score to predict biochemical failure (bF) after various doses of external beam radiotherapy (EBRT) and/or permanent seed low-dose rate (LDR) prostate brachytherapy (PB). We retrospectively analysed 345 patients with intermediate-risk prostate cancer, with PSA levels of 10-20 ng/mL and/or Gleason 7 including 244 EBRT patients (70.2-79.2 Gy) and 101 patients treated with LDR PB. The minimum follow-up was 3 years. No patient received primary androgen-deprivation therapy. bF was defined according to the Phoenix definition. Cox regression analysis was used to estimate the differences between CAPRA groups. The overall bF rate was 13% (45/345). The CAPRA score, as a continuous variable, was statistically significant in multivariate analysis for predicting bF (hazard ratio [HR] 1.37, 95% confidence interval [CI] 1.10-1.72, P = 0.006). There was a trend for a lower bF rate in patients treated with LDR PB when compared with those treated by EBRT ≤ 74 Gy (HR 0.234, 95% CI 0.05-1.03, P = 0.055) in multivariate analysis. In the subgroup of patients with a CAPRA score of 3-5, CAPRA remained predictive of bF as a continuous variable (HR 1.51, 95% CI 1.01-2.27, P = 0.047) in multivariate analysis. The CAPRA score is useful for predicting biochemical recurrence in patients treated for intermediate-risk prostate cancer with EBRT or LDR PB. It could help in treatment decisions. © 2013 The Authors. BJU International © 2013 BJU International.

  1. On the risk to low doses (<100 mSv) of ionizing radiation during medical imaging procedures - IOMP policy statement

    International Nuclear Information System (INIS)

    Pradhan, A.S.

    2013-01-01

    The science committee of International Organization for Medical Physics (IOMP) developed a policy statement on the predictions of radiation-induced cancers and cancer deaths in patients exposed to low doses (<100 mSv) of ionizing radiation during medical imaging; this statement has been approved by the IOMP council. In order to attract the attention of medical physicists, an editorial (1) titled 'Risk of Medical Imaging' that includes the said statement has recently been published in Medical Physics journal of American Association of Physicists in Medicine (AAPM). As stated, IOMP represents 80 national and 6 regional medical physics organizations and 18,000 medical physicists worldwide. The IOMP affiliated bodies/organizations in different countries (such as Association of Medical Physicists of India, AMPI) have been encouraged to reproduce the IOMP statement in their journals/newsletters for the benefit of larger community of medical physicists. The IOMP statement is reproduced below (readers may also go through the supportive literature listed in references). It is hoped that this policy statement will have some deterrent influence on the continued propagation of unproven risk related to medical imaging procedures conducted with small doses.

  2. Mechanism-based risk assessment strategy for drug-induced cholestasis using the transcriptional benchmark dose derived by toxicogenomics.

    Science.gov (United States)

    Kawamoto, Taisuke; Ito, Yuichi; Morita, Osamu; Honda, Hiroshi

    2017-01-01

    Cholestasis is one of the major causes of drug-induced liver injury (DILI), which can result in withdrawal of approved drugs from the market. Early identification of cholestatic drugs is difficult due to the complex mechanisms involved. In order to develop a strategy for mechanism-based risk assessment of cholestatic drugs, we analyzed gene expression data obtained from the livers of rats that had been orally administered with 12 known cholestatic compounds repeatedly for 28 days at three dose levels. Qualitative analyses were performed using two statistical approaches (hierarchical clustering and principle component analysis), in addition to pathway analysis. The transcriptional benchmark dose (tBMD) and tBMD 95% lower limit (tBMDL) were used for quantitative analyses, which revealed three compound sub-groups that produced different types of differential gene expression; these groups of genes were mainly involved in inflammation, cholesterol biosynthesis, and oxidative stress. Furthermore, the tBMDL values for each test compound were in good agreement with the relevant no observed adverse effect level. These results indicate that our novel strategy for drug safety evaluation using mechanism-based classification and tBMDL would facilitate the application of toxicogenomics for risk assessment of cholestatic DILI.

  3. Application of non-dose/risk indicators for confidence-building in the H12 safety assessment

    International Nuclear Information System (INIS)

    Miyahara, K.; Makino, H.; Takasu, A.; Naito, M.; Umeke, H.; Wakasugi, K.; Ishiguro, K.

    2002-01-01

    In the H12 study, non-dose/risk safety indicators have also been considered with a view to increasing confidence in the safety assessment. The H12 safety assessment considers system evolution for a range of scenarios; not only normal groundwater scenarios but also isolation failure scenarios due to unlikely natural disruptive events. The calculated nuclide concentrations and fluxes in the surface environment for the reference groundwater scenario were compared with measurements of naturally occurring nuclides. This comparison indicated that the concentration and fluxes of radionuclides released from the repository would be several orders of magnitude lower than those of natural radionuclides. There may exist cases, such as some natural disruptive events, where the likelihood of occurrence is extremely low and the 'Reference Biosphere' approach is difficult to be applied for biosphere modelling. The use of qualitative assessment to allow comparison with naturally occurring nuclides based on observations of natural systems may play a role in supporting the robustness of the system concept. These examples suggest that relevant application of these non-dose/risk indicators supports a more robust case. An advantage to applying such indicators is that both technical and non-technical audiences can judge the relative, long-term impact of a deep geological repository. (author)

  4. No difference in dose distribution in organs at risk in postmastectomy radiotherapy with or without breast implant reconstruction

    International Nuclear Information System (INIS)

    Liljegren, Annelie; Unukovych, Dmytro; Gagliardi, Giovanna; Bjöhle, Judith; Wickman, Marie; Johansson, Hemming; Sandelin, Kerstin

    2014-01-01

    The aim of this study was to quantify the variation in doses to organs at risk (ipsilateral lung and heart) and the clinical target volume (CTV) in the presence of breast implants. In this retrospective cohort study, patients were identified through the National Breast Cancer Register. Consecutive breast cancer patients undergoing mastectomy between 2009 and 2011 and completing a full course of postmastectomy radiotherapy (PMRT) were eligible. All included patients (n = 818) were identified in the ARIA© oncology information system and further stratified for immediate breast reconstruction (IBR+, n = 162) and no immediate breast reconstruction (IBR-, n = 656). Dose statistics for ipsilateral lung, heart and CTV were retrieved from the system. Radiation plans for patients with chest wall (CW) only (n = 242) and CW plus lymph nodes (n = 576) irradiation were studied separately. The outcome variables were dichotomized as follows: lung, V 20Gy ≤ 30% vs. V 20Gy > 30%; heart, D mean ≤ 5 Gy vs. D mean > 5 Gy; CTV, V 95% ≥ median vs. V 95% < median. In the univariate and multivariate regression models no correlation between potential confounders (i.e. breast reconstruction, side of PMRT, CW index) and the outcome variables was found. Multivariate analysis of CW plus lymph nodes radiation plans, for example, showed no association of breast reconstruction with dosimetric outcomes in neither lung nor heart- lung V 20Gy (odds ratio [OR]: 0.6, 95%CI, 0.4 to 1.0, p = 0.07) or heart D mean (OR: 1.2, 95%CI, 0.5 to 3.1, p = 0.72), respectively. CTV was statistically significantly larger in the IBR+ group (i.e. included breast implant), but no correlation between the implant type and dosimetric characteristics of the organs at risk was revealed. In the current study, the presence of breast implants during postmastectomy radiotherapy was not associated with increased doses to ipsilateral lung and heart, but CTV definition and its dosimetric characteristics urge further

  5. Reduction of Dose Delivered to Organs at Risk in Prostate Cancer Patients via Image-Guided Radiation Therapy

    International Nuclear Information System (INIS)

    Pawlowski, Jason M.; Yang, Eddy S.; Malcolm, Arnold W.; Coffey, Charles W.; Ding, George X.

    2010-01-01

    Purpose: To determine whether image guidance can improve the dose delivered to target organs and organs at risk (OARs) for prostate cancer patients treated with intensity-modulated radiotherapy (IMRT). Methods and Materials: Eight prostate cancer patients were treated with IMRT to 76 Gy at 2 Gy per fraction. Daily target localization was performed via alignment of three intraprostatic fiducials and weekly kV-cone beam computed tomography (CBCT) scans. The prostate and OARs were manually contoured on each CBCT by a single physician. Daily patient setup shifts were obtained by comparing alignment of skin tattoos with the treatment position based on fiducials. Treatment fields were retrospectively applied to CBCT scans. The dose distributions were calculated using actual treatment plans (an 8-mm PTV margin everywhere except for 6-mm posteriorly) with and without image guidance shifts. Furthermore, the feasibility of margin reduction was evaluated by reducing planning margins to 4 mm everywhere except for 3 mm posteriorly. Results: For the eight treatment plans on the 56 CBCT scans, the average doses to 98% of the prostate (D98) were 102% (range, 99-104%) and 99% (range, 45-104%) with and without image guidance, respectively. Using margin reduction, the average D98s were 100% (range, 84-104%) and 92% (range, 40-104%) with and without image guidance, respectively. Conclusions: Currently, margins used in IMRT plans are adequate to deliver a dose to the prostate with conventional patient positioning using skin tattoos or bony anatomy. The use of image guidance may facilitate significant reduction of planning margins. Future studies to assess the efficacy of decreasing margins and improvement of treatment-related toxicities are warranted.

  6. Potential of a Pharmacogenetic-Guided Algorithm to Predict Optimal Warfarin Dosing in a High-Risk Hispanic Patient

    Directory of Open Access Journals (Sweden)

    Dagmar F. Hernandez-Suarez MD

    2016-12-01

    Full Text Available Deep abdominal vein thrombosis is extremely rare among thrombotic events secondary to the use of contraceptives. A case to illustrate the clinical utility of ethno-specific pharmacogenetic testing in warfarin management of a Hispanic patient is reported. A 37-year-old Hispanic Puerto Rican, non-gravid female with past medical history of abnormal uterine bleeding on hormonal contraceptive therapy was evaluated for abdominal pain. Physical exam was remarkable for unspecific diffuse abdominal tenderness, and general initial laboratory results—including coagulation parameters—were unremarkable. A contrast-enhanced computed tomography showed a massive thrombosis of the main portal, splenic, and superior mesenteric veins. On admission the patient was started on oral anticoagulation therapy with warfarin at 5 mg/day and low-molecular-weight heparin. The prediction of an effective warfarin dose of 7.5 mg/day, estimated by using a recently developed pharmacogenetic-guided algorithm for Caribbean Hispanics, coincided with the actual patient’s warfarin dose to reach the international normalized ratio target. We speculate that the slow rise in patient’s international normalized ratio observed on the initiation of warfarin therapy, the resulting high risk for thromboembolic events, and the required warfarin dose of 7.5 mg/day are attributable in some part to the presence of the NQO1 *2 (g.559C>T, p.P187S polymorphism, which seems to be significantly associated with resistance to warfarin in Hispanics. By adding genotyping results of this novel variant, the predictive model can inform clinicians better about the optimal warfarin dose in Caribbean Hispanics. The results highlight the potential for pharmacogenetic testing of warfarin to improve patient care.

  7. The risk of chronic myeloid leukemia: Can the dose-response curve be U-shaped?

    Czech Academy of Sciences Publication Activity Database

    Radivoyevitch, T.; Kozubek, Stanislav; Sachs, R. K.

    2002-01-01

    Roč. 157, č. 1 (2002), s. 106-109 ISSN 0033-7587 R&D Projects: GA ČR GA202/01/0197; GA ČR GA301/01/0186; GA AV ČR IBS5004010 Keywords : radiation risk * chronic myeloid leukemia * chromosome translocation Subject RIV: BO - Biophysics Impact factor: 2.768, year: 2002

  8. Impact of delineation uncertainties on dose to organs at risk in CT-guided intracavitary brachytherapy.

    LENUS (Irish Health Repository)

    Duane, Frances K

    2014-08-07

    This study quantifies the inter- and intraobserver variations in contouring the organs at risk (OARs) in CT-guided brachytherapy (BT) for the treatment of cervical carcinoma. The dosimetric consequences are reported in accordance with the current Gynecological Groupe Européen de Curiethérapie\\/European Society for Therapeutic Radiology and Oncology guidelines.

  9. Food Groups and Risk of Hypertension: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies.

    Science.gov (United States)

    Schwingshackl, Lukas; Schwedhelm, Carolina; Hoffmann, Georg; Knüppel, Sven; Iqbal, Khalid; Andriolo, Violetta; Bechthold, Angela; Schlesinger, Sabrina; Boeing, Heiner

    2017-11-01

    The aim of this systematic review and meta-analysis was to summarize the evidence on the relation of the intakes of 12 major food groups, including whole grains, refined grains, vegetables, fruits, nuts, legumes, eggs, dairy, fish, red meat, processed meat, and sugar-sweetened beverages (SSBs) with the risk of hypertension. PubMed, Scopus, and Web of Science were searched systematically until June 2017 for prospective studies having quantitatively investigated the above-mentioned foods. We conducted meta-analysis on the highest compared with the lowest intake categories and linear and nonlinear dose-response meta-analyses to analyze the association. Summary RRs and 95% CIs were estimated by using a random-effects model. Overall, 28 reports were included in the meta-analysis. An inverse association for the risk of hypertension was observed for 30 g whole grains/d (RR: 0.92; 95% CI: 0.87, 0.98), 100 g fruits/d (RR: 0.97; 95% CI: 0.96, 0.99), 28 g nuts/d (RR: 0.70; 95% CI: 0.45, 1.08), and 200 g dairy/d (RR: 0.95; 95% CI: 0.94, 0.97), whereas a positive association for 100 g red meat/d (RR: 1.14; 95% CI: 1.02, 1.28), 50 g processed meat/d (RR: 1.12; 95% CI: 1.00, 1.26), and 250 mL SSB/d (RR: 1.07; 95% CI: 1.04, 1.10) was seen in the linear dose-response meta-analysis. Indication for nonlinear relations of the intakes of whole grains, fruits, fish, and processed meats with the risk of hypertension was detected. In summary, this comprehensive dose-response meta-analysis of 28 reports identified optimal intakes of whole grains, fruits, nuts, legumes, dairy, red and processed meats, and SSBs related to the risk of hypertension. These findings need to be seen under the light of very-low to low quality of meta-evidence. However, the findings support the current dietary guidelines in the prevention of hypertension. © 2017 American Society for Nutrition.

  10. Causes of Mortality After Dose-Escalated Radiation Therapy and Androgen Deprivation for High-Risk Prostate Cancer

    International Nuclear Information System (INIS)

    Tendulkar, Rahul D.; Hunter, Grant K.; Reddy, Chandana A.; Stephans, Kevin L.; Ciezki, Jay P.; Abdel-Wahab, May; Stephenson, Andrew J.; Klein, Eric A.; Mahadevan, Arul; Kupelian, Patrick A.

    2013-01-01

    Purpose: Men with high-risk prostate cancer have other competing causes of mortality; however, current risk stratification schema do not account for comorbidities. We aim to identify the causes of death and factors predictive for mortality in this population. Methods and Materials: A total of 660 patients with high-risk prostate cancer were treated with definitive high-dose external beam radiation therapy (≥74 Gy) and androgen deprivation (AD) between 1996 and 2009 at a single institution. Cox proportional hazards regression analysis was conducted to determine factors predictive of survival. Results: The median radiation dose was 78 Gy, median duration of AD was 6 months, and median follow-up was 74 months. The 10-year overall survival (OS) was 60.6%. Prostate cancer was the leading single cause of death, with 10-year mortality of 14.1% (95% CI 10.7-17.6), compared with other cancers (8.4%, 95% CI 5.7-11.1), cardiovascular disease (7.3%, 95% CI 4.7-9.9), and all other causes (10.4%, 95% CI 7.2-13.6). On multivariate analysis, older age (HR 1.55, P=.002) and Charlson comorbidity index score (CS) ≥1 (HR 2.20, P<.0001) were significant factors predictive of OS, whereas Gleason score, T stage, prostate-specific antigen, duration of AD, radiation dose, smoking history, and body mass index were not. Men younger than 70 years of age with CS = 0 were more likely to die of prostate cancer than any other cause, whereas older men or those with CS ≥1 more commonly suffered non-prostate cancer death. The cumulative incidences of prostate cancer-specific mortality were similar regardless of age or comorbidities (P=.60). Conclusions: Men with high-risk prostate cancer are more likely to die of causes other than prostate cancer, except for the subgroup of men younger than 70 years of age without comorbidities. Only older age and presence of comorbidities significantly predicted for OS, whereas prostate cancer- and treatment-related factors did not

  11. Knowledge on radiation dose-rate for risk communication on nuclear power plants

    International Nuclear Information System (INIS)

    Sugiyama, Ken-ichiro

    2013-01-01

    The sense of anxiety on radiation after Fukushima Dai-ichi accident has not disappeared because of the nightmare scenario on radiation cultivated through the Cold War era starting at the atomic bomb dropping at Hiroshima and Nagasaki. In the present paper, from the viewpoint of establishing the social acceptance of nuclear power plants as well as new reasonable regulation, biological defense in depth (production of anti-oxidants, DNA repair, cell death/apoptosis, and immune defense mechanisms) found in a few decades are presented in comparison with the linear no-threshold (LNT) model for the induction of cancer in the range up to 100 mSv (as single or annual doses) applied for the present regulation. (author)

  12. High-dose I-131 MIBG treatment for young children with high-risk neuroblastoma, and its practical problem. From the experience of the youngest case in Japan

    International Nuclear Information System (INIS)

    Araki, Raita; Nishimura, Ryosei; Mase, Shintaro

    2012-01-01

    High-dose I-131 MIBG (metaiodobenzylguanidine) therapy combined with auto- or allo-hematopoietic stem cell transplantation is becoming a potential treatment for patients with high-risk neuroblastoma worldwide. However, only older children, who can perform personal care, had been given high-dose I-131 MIBG treatment to avoid the needless radiation exposure to caregivers and medical staff in Japan. In this case report, we have used the high dose MIBG therapy followed by autologous PBSCT (peripheral blood stem cell transplantation) for a 1-year-old boy with a newly diagnosed high-risk neuroblastoma with MYCN amplifications. The total radiation exposure to all parties involved was very limited, even in the youngest case in Japan, probably due to adequate preparations. This encouraging experience may remove the age limit for high-dose I-131 MIBG treatment for the patients with high-risk neuroblastoma in Japan. (author)

  13. Can we avoid dose escalation for intermediate-risk prostate cancer in the setting of short-course neoadjuvant androgen deprivation?

    Science.gov (United States)

    Shakespeare, Thomas P; Wilcox, Shea W; Aherne, Noel J

    2016-01-01

    Both dose-escalated external beam radiotherapy (DE-EBRT) and androgen deprivation therapy (ADT) improve the outcomes in patients with intermediate-risk prostate cancer. Despite this, there are only few reports evaluating DE-EBRT for patients with intermediate-risk prostate cancer receiving neoadjuvant ADT, and virtually no studies investigating dose escalation >74 Gy in this setting. We aimed to determine whether DE-EBRT >74 Gy improved the outcomes for patients with intermediate-risk prostate cancer who received neoadjuvant ADT. In our institution, patients with intermediate-risk prostate cancer were treated with neoadjuvant ADT and DE-EBRT, with doses sequentially increasing from 74 Gy to 76 Gy and then to 78 Gy between 2006 and 2012. We identified 435 patients treated with DE-EBRT and ADT, with a median follow-up of 70 months. For the 74 Gy, 76 Gy, and 78 Gy groups, five-year biochemical disease-free survival rates were 95.0%, 97.8%, and 95.3%, respectively; metastasis-free survival rates were 99.1%, 100.0%, and 98.6%, respectively; and prostate cancer-specific survival rate was 100% for all three dose levels. There was no significant benefit for dose escalation either on univariate or multivariate analysis for any outcome. There was no benefit for DE-EBRT >74 Gy in our cohort of intermediate-risk prostate cancer patients treated with neoadjuvant ADT. Given the higher risks of toxicity associated with dose escalation, it may be feasible to omit dose escalation in this group of patients. Randomized studies evaluating dose de-escalation should be considered.

  14. A tiered approach for integrating exposure and dosimetry with in vitro dose-response data in the modern risk assessment paradigm

    Science.gov (United States)

    High-throughput (HT) risk screening approaches apply in vitro dose-response data to estimate potential health risks that arise from exposure to chemicals. However, much uncertainty is inherent in relating bioactivities observed in an in vitro system to the perturbations of biolog...

  15. Health Risk Assessment for Uranium in Groundwater - An Integrated Case Study Based on Hydrogeological Characterization and Dose Calculation

    Science.gov (United States)

    Franklin, M. R.; Veiga, L. H.; Py, D. A., Jr.; Fernandes, H. M.

    2010-12-01

    The uranium mining and milling facilities of Caetité (URA) is the only active uranium production center in Brazil. Operations take place at a very sensitive semi-arid region in the country where water resources are very scarce. Therefore, any contamination of the existing water bodies may trigger critical consequences to local communities because their sustainability is closely related to the availability of the groundwater resources. Due to the existence of several uranium anomalies in the region, groundwater can present radionuclide concentrations above the world average. The radiological risk associated to the ingestion of these waters have been questioned by members of the local communities, NGO’s and even regulatory bodies that suspected that the observed levels of radionuclide concentrations (specially Unat) could be related to the uranium mining and milling operations. Regardless the origin of these concentrations the fear that undesired health effects were taking place (e.g. increase in cancer incidence) remain despite the fact that no evidence - based on epidemiological studies - is available. This paper intends to present the connections between the local hydrogeology and the radiological characterization of groundwater in the neighboring areas of the uranium production center to understand the implications to the human health risk due to the ingestion of groundwater. The risk assessment was performed, taking into account the radiological and the toxicological risks. Samples from 12 wells have been collected and determinations of Unat, Thnat, 226Ra, 228Ra and 210Pb were performed. The radiation-related risks were estimated for adults and children by the calculation of the annual effective doses. The potential non-carcinogenic effects due to the ingestion of uranium were evaluated by the estimation of the hazard index (HI). Monte Carlo simulations were used to calculate the uncertainty associated with these estimates, i.e. the 95% confidence interval

  16. Intake of fruit and vegetables and risk of bladder cancer: a dose-response meta-analysis of observational studies.

    Science.gov (United States)

    Yao, Baodong; Yan, Yujie; Ye, Xianwu; Fang, Hong; Xu, Huilin; Liu, Yinan; Li, Sheran; Zhao, Yanping

    2014-12-01

    Observational studies suggest an association between fruit and vegetables intake and risk of bladder cancer, but the results are controversial. We therefore summarized the evidence from observational studies in categorical, linear, and nonlinear, dose-response meta-analysis. Pertinent studies were identified by searching EMBASE and PubMed from their inception to August 2013. Thirty-one observational studies involving 12,610 cases and 1,121,649 participants were included. The combined rate ratio (RR, 95 % CI) of bladder cancer for the highest versus lowest intake was 0.83 (0.69-0.99) for total fruit and vegetables, 0.81 (0.70-0.93) for total vegetables, 0.77 (0.69-0.87) for total fruit, 0.84 (0.77-0.91) for cruciferous vegetables, 0.79 (0.68-0.91) for citrus fruits, and 0.74 (0.66-0.84) for yellow-orange vegetables. Subgroup analysis showed study design and gender as possible sources of heterogeneity. A nonlinear relationship was found of citrus fruits intake with risk of bladder cancer (P for nonlinearity = 0.018), and the RRs (95 % CI) of bladder cancer were 0.87 (0.78-0.96), 0.80 (0.67-0.94), 0.79 (0.66-0.94), 0.79 (0.65-0.96), and 0.79 (0.64-0.99) for 30, 60, 90, 120, and 150 g/day. A nonlinear relationship was also found of yellow-orange vegetable intake with risk of bladder cancer risk (P for nonlinearity = 0.033). Some evidence of publication bias was observed for fruit, citrus fruits, and yellow-orange vegetables. This meta-analysis supports the hypothesis that intakes of fruit and vegetables may reduce the risk of bladder cancer. Future well-designed studies are required to confirm this finding.

  17. WE-AB-209-08: Novel Beam-Specific Adaptive Margins for Reducing Organ-At-Risk Doses

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, H; Kamerling, CP; Ziegenhein, P; Nill, S; Oelfke, U [The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London (United Kingdom)

    2016-06-15

    Purpose: Current practice of using 3D margins in radiotherapy with high-energy photon beams provides larger-than-required target coverage. According to the photon depth-dose curve, target displacements in beam direction result in minute changes in dose delivered. We exploit this behavior by generating margins on a per-beam basis which simultaneously account for the relative distance of the target and adjacent organs-at-risk (OARs). Methods: For each beam, we consider only geometrical uncertainties of the target location perpendicular to beam direction. By weighting voxels based on its proximity to an OAR, we generate adaptive margins that yield similar overall target coverage probability and reduced OAR dose-burden, at the expense of increased target volume. Three IMRT plans, using 3D margins and 2D per-beam margins with and without adaptation, were generated for five prostate patients with a prescription dose Dpres of 78Gy in 2Gy fractions using identical optimisation constraints. Systematic uncertainties of 1.1, 1.1, 1.5mm in the LR, SI, and AP directions, respectively, and 0.9, 1.1, 1.0mm for the random uncertainties, were assumed. A verification tool was employed to simulate the effects of systematic and random errors using a population size of 50,000. The fraction of the population that satisfies or violates a given DVH constraint was used for comparison. Results: We observe similar target coverage across all plans, with at least 97.5% of the population meeting the D98%>95%Dpres constraint. When looking at the probability of the population receiving D5<70Gy for the rectum, we observed median absolute increases of 23.61% (range, 2.15%–27.85%) and 6.97% (range, 0.65%–17.76%) using per-beam margins with and without adaptation, respectively, relative to using 3D margins. Conclusion: We observed sufficient and similar target coverage using per-beam margins. By adapting each per-beam margin away from an OAR, we can further reduce OAR dose without significantly

  18. WE-AB-209-08: Novel Beam-Specific Adaptive Margins for Reducing Organ-At-Risk Doses

    International Nuclear Information System (INIS)

    Tsang, H; Kamerling, CP; Ziegenhein, P; Nill, S; Oelfke, U

    2016-01-01

    Purpose: Current practice of using 3D margins in radiotherapy with high-energy photon beams provides larger-than-required target coverage. According to the photon depth-dose curve, target displacements in beam direction result in minute changes in dose delivered. We exploit this behavior by generating margins on a per-beam basis which simultaneously account for the relative distance of the target and adjacent organs-at-risk (OARs). Methods: For each beam, we consider only geometrical uncertainties of the target location perpendicular to beam direction. By weighting voxels based on its proximity to an OAR, we generate adaptive margins that yield similar overall target coverage probability and reduced OAR dose-burden, at the expense of increased target volume. Three IMRT plans, using 3D margins and 2D per-beam margins with and without adaptation, were generated for five prostate patients with a prescription dose Dpres of 78Gy in 2Gy fractions using identical optimisation constraints. Systematic uncertainties of 1.1, 1.1, 1.5mm in the LR, SI, and AP directions, respectively, and 0.9, 1.1, 1.0mm for the random uncertainties, were assumed. A verification tool was employed to simulate the effects of systematic and random errors using a population size of 50,000. The fraction of the population that satisfies or violates a given DVH constraint was used for comparison. Results: We observe similar target coverage across all plans, with at least 97.5% of the population meeting the D98%>95%Dpres constraint. When looking at the probability of the population receiving D5<70Gy for the rectum, we observed median absolute increases of 23.61% (range, 2.15%–27.85%) and 6.97% (range, 0.65%–17.76%) using per-beam margins with and without adaptation, respectively, relative to using 3D margins. Conclusion: We observed sufficient and similar target coverage using per-beam margins. By adapting each per-beam margin away from an OAR, we can further reduce OAR dose without significantly

  19. High-dose thalidomide increases the risk of peripheral neuropathy in the treatment of ankylosing spondylitis.

    Science.gov (United States)

    Xue, Hong-Xia; Fu, Wen-Yi; Cui, Hua-Dong; Yang, Li-Li; Zhang, Ning; Zhao, Li-Juan

    2015-05-01

    Thalidomide is an effective drug for the treatment of ankylosing spondylitis but might induce peripheral neuropathy. This major adverse reaction has attracted much concern. The current study aimed to observe the incidence of thalidomide-induced peripheral neuropathy among ankylosing spondylitis patients for 1 year after treatment. In this study, 207 ankylosing spondylitis cases received thalidomide treatment, while 116 ankylosing spondylitis cases received other treatments. Results showed that the incidence of thalidomide-induced peripheral neuropathy in the thalidomide group was higher than that in the non-thalidomide group. There was no significant difference in the incidence of neuropathy between the peripheral neuropathy among patients receiving 25, 50, 75, or 100 mg thalidomide per day was 4.6%, 8.5%, 17.1%, 21.7%, respectively. The incidence was significantly different between the groups receiving 25 mg and 100 mg thalidomide. In conclusion, thalidomide can induce peripheral neuropathy within 1 year after treatment of ankylosing spondylitis; however, age and gender have no obvious impact on the incidence of peripheral neuropathy. The incidence of peripheral neuropathy is associated with increasing daily doses of thalidomide.

  20. Task 3 Report - PCBs in the Environment Near the Oak Ridge Reservation - A Reconstruction of Historical Doses and Health Risks

    Energy Technology Data Exchange (ETDEWEB)

    Price, Paul S; Widner, Thomas; Bonnevie, Nancy; Schmidt, Charlie; McCrodden-Hamblen, Jane; Vantaggio, Joanne; Gwinn, Patrick

    1999-07-01

    from non -cancer effects of PCBs. However, for Watts Bar, these risks were mainly due to sources of PCBs other than the ORR; the releases from the ORR appear to have placed an additional one to two percent of the total number of fish consumers potentially at risk. This percentage corresponds to approximately 1,000-2,000 fish consumers over the last 50 years. This report is one in a set of eight technical reports on the Oak Ridge Offsite Dose Reconstruction.

  1. Uranium in soil and gamma dose rate as proxies for the indoor radon risk: situation in Belgium

    International Nuclear Information System (INIS)

    Tondeur, F.; Cinelli, G.; Dehandschutter, B.

    2017-01-01

    Radon risk maps are usually based either on indoor radon data, or on measurements of soil gas radon and soil permeability. If these data are not available or not sufficient, it was suggested that other data could be used as an approximate substitute (a proxy) to the missing information, like the concentration of 238 U or 226 Ra in soils or the terrestrial gamma dose rate (TGDR). We examine here the correlation between airborne measurements of soil U and indoor radon, and between airborne U and TGDR, and their link with affected/unaffected areas. No clear correlation is found between airborne U and affected areas, as strongly affected areas are not characterised by a higher U level. Only the moderately affected area of Condroz can be connected to a higher U level, related to a few U anomalies. TGDR shows a rather good correlation with airborne U, but its relation with radon risk is less clear. Soil uranium and TGDR may help to screen out areas with very low U and very low TGDR, which have a low indoor radon risk, but they cannot be considered as good proxies for predicting radon-affected areas in Belgium. (authors)

  2. Is it beneficial to selectively boost high-risk tumor subvolumes? A comparison of selectively boosting high-risk tumor subvolumes versus homogeneous dose escalation of the entire tumor based on equivalent EUD plans

    International Nuclear Information System (INIS)

    Kim, Yusung; To me, Wolfgang A.

    2008-01-01

    Purpose. To quantify and compare expected local tumor control and expected normal tissue toxicities between selective boosting IMRT and homogeneous dose escalation IMRT for the case of prostate cancer. Methods. Four different selective boosting scenarios and three different high-risk tumor subvolume geometries were designed to compare selective boosting and homogeneous dose escalation IMRT plans delivering the same equivalent uniform dose (EUD) to the entire PTV. For each scenario, differences in tumor control probability between both boosting strategies were calculated for the high-risk tumor subvolume and remaining low-risk PTV, and were visualized using voxel based iso-TCP maps. Differences in expected rectal and bladder complications were quantified using radiobiological indices (generalized EUD (gEUD) and normal tissue complication probability (NTCP)) as well as %-volumes. Results. For all investigated scenarios and high-risk tumor subvolume geometries, selective boosting IMRT improves expected TCP compared to homogeneous dose escalation IMRT, especially when lack of control of the high-risk tumor subvolume could be the cause for tumor recurrence. Employing, selective boosting IMRT significant increases in expected TCP can be achieved for the high-risk tumor subvolumes. The three conventional selective boosting IMRT strategies, employing physical dose objectives, did not show significant improvement in rectal and bladder sparing as compared to their counterpart homogeneous dose escalation plans. However, risk-adaptive optimization, utilizing radiobiological objective functions, resulted in reduction in NTCP for the rectum when compared to its corresponding homogeneous dose escalation plan. Conclusions. Selective boosting is a more effective method than homogeneous dose escalation for achieving optimal treatment outcomes. Furthermore, risk-adaptive optimization increases the therapeutic ratio as compared to conventional selective boosting IMRT

  3. Pharmacogenetics-based warfarin dosing algorithm decreases time to stable anticoagulation and the risk of major hemorrhage: an updated meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Wang, Zhi-Quan; Zhang, Rui; Zhang, Peng-Pai; Liu, Xiao-Hong; Sun, Jian; Wang, Jun; Feng, Xiang-Fei; Lu, Qiu-Fen; Li, Yi-Gang

    2015-04-01

    Warfarin is yet the most widely used oral anticoagulant for thromboembolic diseases, despite the recently emerged novel anticoagulants. However, difficulty in maintaining stable dose within the therapeutic range and subsequent serious adverse effects markedly limited its use in clinical practice. Pharmacogenetics-based warfarin dosing algorithm is a recently emerged strategy to predict the initial and maintaining dose of warfarin. However, whether this algorithm is superior over conventional clinically guided dosing algorithm remains controversial. We made a comparison of pharmacogenetics-based versus clinically guided dosing algorithm by an updated meta-analysis. We searched OVID MEDLINE, EMBASE, and the Cochrane Library for relevant citations. The primary outcome was the percentage of time in therapeutic range. The secondary outcomes were time to stable therapeutic dose and the risks of adverse events including all-cause mortality, thromboembolic events, total bleedings, and major bleedings. Eleven randomized controlled trials with 2639 participants were included. Our pooled estimates indicated that pharmacogenetics-based dosing algorithm did not improve percentage of time in therapeutic range [weighted mean difference, 4.26; 95% confidence interval (CI), -0.50 to 9.01; P = 0.08], but it significantly shortened the time to stable therapeutic dose (weighted mean difference, -8.67; 95% CI, -11.86 to -5.49; P pharmacogenetics-based algorithm significantly reduced the risk of major bleedings (odds ratio, 0.48; 95% CI, 0.23 to 0.98; P = 0.04), but it did not reduce the risks of all-cause mortality, total bleedings, or thromboembolic events. Our results suggest that pharmacogenetics-based warfarin dosing algorithm significantly improves the efficiency of International Normalized Ratio correction and reduces the risk of major hemorrhage.

  4. A comparison of radiation doses and risks between spent fuel transport/storage and selected non-nuclear activities

    International Nuclear Information System (INIS)

    Pennington, C.W.

    2003-01-01

    Spent fuel transport and storage have achieved an exemplary safety record over four decades within both the United States (US) and the global community at large. This paper offers an assessment demonstrating the safety of spent fuel transport and storage packagings relative to currently accepted but unregulated non-nuclear activities and practices within society. Over the last quarter of a century, several spent fuel transport and storage packaging test programmes have produced data that allow calculation of potential releases and population doses resulting from a terrorist attack. The US Department of Energy (DOE) has used this information to develop projected worst-case, low probability population exposures as part of the Final Environmental Impact Statement (FEIS) for the Yucca Mountain repository. The paper discusses potential population exposures from these packagings based on analysis and testing under beyond-design-basis (BDB) events, including missile attacks, and then defines and defends an acceptance criterion for the bounding outcomes of these events, based upon current accepted activities within society that produce high radiation doses to the general public. These activities involve unregulated technologies and practices within society that yield population doses significantly exceeding those that would result from such hypothetical and highly improbable events as a terrorist missile attack on a spent fuel transport or storage packaging. In particular, technologically enhanced natural radiation (TENR) exposures from building materials, farming, and masonry construction are highlighted. Recent landmark work by the US National Academy of Sciences (NAS) and by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) are cited in support of this assessment, along with work from the US Environmental Protection Agency (EPA). From this compelling evidence, it is concluded that spent fuel transport and storage represent a low

  5. Dose-Escalated Hypofractionated Intensity-Modulated Radiotherapy in High-Risk Carcinoma of the Prostate: Outcome and Late Toxicity

    Directory of Open Access Journals (Sweden)

    David Thomson

    2012-01-01

    Results. Median followup was 84 months. Five-year overall survival (OS was 83% and biochemical progression-free survival (bPFS was 50% for 57 Gy. Five-year OS was 75% and bPFS 58% for 60 Gy. At 7 years, toxicity by RTOG criteria was acceptable with no grade 3 or above toxicity. Compared with baseline, there was no significant change in urinary symptoms at 2 or 7 years. Bowel symptoms were stable between 2 and 7 years. All patients continued to have significant sexual dysfunction. Conclusion. In high-risk prostate cancer, dose-escalated hypofractionated radiotherapy using IMRT results in encouraging outcomes and acceptable late toxicity.

  6. The use of safety indicators, complementary to dose and risk, in the assessment of radioactive waste disposal

    International Nuclear Information System (INIS)

    Gera, F.; Vovk, I.; Wingefors, S.

    1998-01-01

    The use of safety indicators, other than dose and risk, to complement the safety assessment of disposal systems for radioactive waste, is not a new idea. Several possible approaches have been proposed through the years, including a discussion in an IAEA document of 1994. The present paper reviews critically the various proposed indicators, identifies the most promising ones and suggests a possible approach for the assessment of their viability. In particular it suggests that a Coordinated Research Project should be organized with the main objectives of assembling, reviewing and generating the necessary scientific information on natural values, particularly fluxes and concentrations of pollutants, and on their impacts on public health and environmental quality. (author)

  7. Dynamics of rectal balloon implant shrinkage in prostate VMAT. Influence on anorectal dose and late rectal complication risk

    Energy Technology Data Exchange (ETDEWEB)

    Vanneste, Ben G.L.; Wijk, Y. van; Lutgens, L.C.; Limbergen, E.J. van; Lambin, P. [Maastricht University Medical Center+, Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Lin, E.N. van [Radiotherapy Bonn-Rhein-Sieg, Troisdorf (Germany); Beek, K. van de [Maastricht University Medical Center+, Department of Urology, Maastricht (Netherlands); Hoffmann, A.L. [Maastricht University Medical Center+, Department of Radiation Oncology (MAASTRO),