WorldWideScience

Sample records for brachytherapy human error

  1. Human error in remote Afterloading Brachytherapy

    International Nuclear Information System (INIS)

    Remote Afterloading Brachytherapy (RAB) is a medical process used in the treatment of cancer. RAB uses a computer-controlled device to remotely insert and remove radioactive sources close to a target (or tumor) in the body. Some RAB problems affecting the radiation dose to the patient have been reported and attributed to human error. To determine the root cause of human error in the RAB system, a human factors team visited 23 RAB treatment sites in the US. The team observed RAB treatment planning and delivery, interviewed RAB personnel, and performed walk-throughs, during which staff demonstrated the procedures and practices used in performing RAB tasks. Factors leading to human error in the RAB system were identified. The impact of those factors on the performance of RAB was then evaluated and prioritized in terms of safety significance. Finally, the project identified and evaluated alternative approaches for resolving the safety significant problems related to human error

  2. Human factors evaluation of remote afterloading brachytherapy: Human error and critical tasks in remote afterloading brachytherapy and approaches for improved system performance. Volume 1

    International Nuclear Information System (INIS)

    Remote Afterloading Brachytherapy (RAB) is a medical process used in the treatment of cancer. RAB uses a computer-controlled device to remotely insert and remove radioactive sources close to a target (or tumor) in the body. Some RAB problems affecting the radiation dose to the patient have been reported and attributed to human error. To determine the root cause of human error in the RAB system, a human factors team visited 23 RAB treatment sites in the US The team observed RAB treatment planning and delivery, interviewed RAB personnel, and performed walk-throughs, during which staff demonstrated the procedures and practices used in performing RAB tasks. Factors leading to human error in the RAB system were identified. The impact of those factors on the performance of RAB was then evaluated and prioritized in terms of safety significance. Finally, the project identified and evaluated alternative approaches for resolving the safety significant problems related to human error

  3. Human factors evaluation of remote afterloading brachytherapy: Human error and critical tasks in remote afterloading brachytherapy and approaches for improved system performance. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Callan, J.R.; Kelly, R.T.; Quinn, M.L. [Pacific Science and Engineering Group, San Diego, CA (United States)] [and others

    1995-05-01

    Remote Afterloading Brachytherapy (RAB) is a medical process used in the treatment of cancer. RAB uses a computer-controlled device to remotely insert and remove radioactive sources close to a target (or tumor) in the body. Some RAB problems affecting the radiation dose to the patient have been reported and attributed to human error. To determine the root cause of human error in the RAB system, a human factors team visited 23 RAB treatment sites in the US The team observed RAB treatment planning and delivery, interviewed RAB personnel, and performed walk-throughs, during which staff demonstrated the procedures and practices used in performing RAB tasks. Factors leading to human error in the RAB system were identified. The impact of those factors on the performance of RAB was then evaluated and prioritized in terms of safety significance. Finally, the project identified and evaluated alternative approaches for resolving the safety significant problems related to human error.

  4. Brachytherapy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Brachytherapy What is Brachytherapy and how is it used? ... will I feel during this procedure? What is brachytherapy and how is it used? Brachytherapy is a ...

  5. [Brachytherapy].

    Science.gov (United States)

    Itami, Jun

    2014-12-01

    Brachytherapy do require a minimal expansion of CTV to obtain PTV and it is called as ultimate high precision radiation therapy. In high-dose rate brachytherapy, applicators will be placed around or into the tumor and CT or MRI will be performed with the applicators in situ. With such image-guided brachytherapy (IGBT) 3-dimensional treatment planning becomes possible and DVH of the tumor and organs at risk can be obtained. It is now even possible to make forward planning satisfying dose constraints. Traditional subjective evaluation of brachytherapy can be improved to the objective one by IGBT. Brachytherapy of the prostate cancer, cervical cancer, and breast cancer with IGBT technique was described. PMID:25596048

  6. A theory of human error

    Science.gov (United States)

    Mcruer, D. T.; Clement, W. F.; Allen, R. W.

    1980-01-01

    Human error, a significant contributing factor in a very high proportion of civil transport, general aviation, and rotorcraft accidents is investigated. Correction of the sources of human error requires that one attempt to reconstruct underlying and contributing causes of error from the circumstantial causes cited in official investigative reports. A validated analytical theory of the input-output behavior of human operators involving manual control, communication, supervisory, and monitoring tasks which are relevant to aviation operations is presented. This theory of behavior, both appropriate and inappropriate, provides an insightful basis for investigating, classifying, and quantifying the needed cause-effect relationships governing propagation of human error.

  7. Human Error: A Concept Analysis

    Science.gov (United States)

    Hansen, Frederick D.

    2007-01-01

    Human error is the subject of research in almost every industry and profession of our times. This term is part of our daily language and intuitively understood by most people however, it would be premature to assume that everyone's understanding of human error s the same. For example, human error is used to describe the outcome or consequence of human action, the causal factor of an accident, deliberate violations,a nd the actual action taken by a human being. As a result, researchers rarely agree on the either a specific definition or how to prevent human error. The purpose of this article is to explore the specific concept of human error using Concept Analysis as described by Walker and Avant (1995). The concept of human error is examined as currently used in the literature of a variety of industries and professions. Defining attributes and examples of model, borderline, and contrary cases are described. The antecedents and consequences of human error are also discussed and a definition of human error is offered.

  8. Human errors and safety culture

    International Nuclear Information System (INIS)

    The purpose of this paper is to focus attention on an apparent paradox: human errors can be a valuable source of safety experience if properly treated. From a punitive management and a climate of fear in reporting human errors toward a safety culture there is a long way but it is the right direction. (Author)

  9. A theory of human error

    Science.gov (United States)

    Mcruer, D. T.; Clement, W. F.; Allen, R. W.

    1981-01-01

    Human errors tend to be treated in terms of clinical and anecdotal descriptions, from which remedial measures are difficult to derive. Correction of the sources of human error requires an attempt to reconstruct underlying and contributing causes of error from the circumstantial causes cited in official investigative reports. A comprehensive analytical theory of the cause-effect relationships governing propagation of human error is indispensable to a reconstruction of the underlying and contributing causes. A validated analytical theory of the input-output behavior of human operators involving manual control, communication, supervisory, and monitoring tasks which are relevant to aviation, maritime, automotive, and process control operations is highlighted. This theory of behavior, both appropriate and inappropriate, provides an insightful basis for investigating, classifying, and quantifying the needed cause-effect relationships governing propagation of human error.

  10. Human Error and Organizational Management

    Directory of Open Access Journals (Sweden)

    Alecxandrina DEACONU

    2009-01-01

    Full Text Available The concern for performance is a topic that raises interest in the businessenvironment but also in other areas that – even if they seem distant from thisworld – are aware of, interested in or conditioned by the economy development.As individual performance is very much influenced by the human resource, wechose to analyze in this paper the mechanisms that generate – consciously or not–human error nowadays.Moreover, the extremely tense Romanian context,where failure is rather a rule than an exception, made us investigate thephenomenon of generating a human error and the ways to diminish its effects.

  11. Adaptive error detection for HDR/PDR brachytherapy: Guidance for decision making during real-time in vivo point dosimetry

    DEFF Research Database (Denmark)

    Kertzscher Schwencke, Gustavo Adolfo Vladimir; Andersen, Claus E.; Tanderup, Kari

    2014-01-01

    Purpose:This study presents an adaptive error detection algorithm (AEDA) for real-timein vivo point dosimetry during high dose rate (HDR) or pulsed dose rate (PDR) brachytherapy (BT) where the error identification, in contrast to existing approaches, does not depend on an a priori reconstruction of...... identify all false errors represented by mispositioned dosimeters contrary to an error detection algorithm relying on the original reconstruction. Conclusions:The study demonstrates that the AEDA error identification during HDR/PDR BT relies on a stable dosimeter position rather than on an accurate...... dosimeter reconstruction, and the AEDA’s capacity to distinguish between true and false error scenarios. The study further shows that the AEDA can offer guidance in decision making in the event of potential errors detected with real-time in vivo point dosimetry....

  12. Human factors evaluation of remote afterloading brachytherapy. Volume 2, Function and task analysis

    International Nuclear Information System (INIS)

    A human factors project on the use of nuclear by-product material to treat cancer using remotely operated afterloaders was undertaken by the Nuclear Regulatory Commission. The purpose of the project was to identify factors that contribute to human error in the system for remote afterloading brachytherapy (RAB). This report documents the findings from the first phase of the project, which involved an extensive function and task analysis of RAB. This analysis identified the functions and tasks in RAB, made preliminary estimates of the likelihood of human error in each task, and determined the skills needed to perform each RAB task. The findings of the function and task analysis served as the foundation for the remainder of the project, which evaluated four major aspects of the RAB system linked to human error: human-system interfaces; procedures and practices; training and qualifications of RAB staff; and organizational practices and policies. At its completion, the project identified and prioritized areas for recommended NRC and industry attention based on all of the evaluations and analyses

  13. Human factors evaluation of remote afterloading brachytherapy. Volume 2, Function and task analysis

    Energy Technology Data Exchange (ETDEWEB)

    Callan, J.R.; Gwynne, J.W. III; Kelly, T.T.; Muckler, F.A. [Pacific Science and Engineering Group, San Diego, CA (United States); Saunders, W.M.; Lepage, R.P.; Chin, E. [University of California San Diego Medical Center, CA (United States). Div. of Radiation Oncology; Schoenfeld, I.; Serig, D.I. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology

    1995-05-01

    A human factors project on the use of nuclear by-product material to treat cancer using remotely operated afterloaders was undertaken by the Nuclear Regulatory Commission. The purpose of the project was to identify factors that contribute to human error in the system for remote afterloading brachytherapy (RAB). This report documents the findings from the first phase of the project, which involved an extensive function and task analysis of RAB. This analysis identified the functions and tasks in RAB, made preliminary estimates of the likelihood of human error in each task, and determined the skills needed to perform each RAB task. The findings of the function and task analysis served as the foundation for the remainder of the project, which evaluated four major aspects of the RAB system linked to human error: human-system interfaces; procedures and practices; training and qualifications of RAB staff; and organizational practices and policies. At its completion, the project identified and prioritized areas for recommended NRC and industry attention based on all of the evaluations and analyses.

  14. Human decision error (HUMDEE) trees

    International Nuclear Information System (INIS)

    Graphical presentations of human actions in incident and accident sequences have been used for many years. However, for the most part, human decision making has been underrepresented in these trees. This paper presents a method of incorporating the human decision process into graphical presentations of incident/accident sequences. This presentation is in the form of logic trees. These trees are called Human Decision Error Trees or HUMDEE for short. The primary benefit of HUMDEE trees is that they graphically illustrate what else the individuals involved in the event could have done to prevent either the initiation or continuation of the event. HUMDEE trees also present the alternate paths available at the operator decision points in the incident/accident sequence. This is different from the Technique for Human Error Rate Prediction (THERP) event trees. There are many uses of these trees. They can be used for incident/accident investigations to show what other courses of actions were available and for training operators. The trees also have a consequence component so that not only the decision can be explored, also the consequence of that decision

  15. Human decision error (HUMDEE) trees

    Energy Technology Data Exchange (ETDEWEB)

    Ostrom, L.T.

    1993-08-01

    Graphical presentations of human actions in incident and accident sequences have been used for many years. However, for the most part, human decision making has been underrepresented in these trees. This paper presents a method of incorporating the human decision process into graphical presentations of incident/accident sequences. This presentation is in the form of logic trees. These trees are called Human Decision Error Trees or HUMDEE for short. The primary benefit of HUMDEE trees is that they graphically illustrate what else the individuals involved in the event could have done to prevent either the initiation or continuation of the event. HUMDEE trees also present the alternate paths available at the operator decision points in the incident/accident sequence. This is different from the Technique for Human Error Rate Prediction (THERP) event trees. There are many uses of these trees. They can be used for incident/accident investigations to show what other courses of actions were available and for training operators. The trees also have a consequence component so that not only the decision can be explored, also the consequence of that decision.

  16. Human errors - human caused, environment caused

    International Nuclear Information System (INIS)

    The importance of human error in the safe operation of Nuclear Plants has been well recognised. The human error could be due to a large number of reasons. Eg. coming from factors like sensing, perceiving, predicting, familiarity, skills, rules, individual performance and environmental factors such as ergonomics, work organisation, procedure, time and duration of work, training, physical environment etc. Two incidents highlighting human caused and environmental caused errors are described. Also a distribution of causes of failure and affected systems of Safety Related Unusual Occurrences is presented on the basis of the reports received by the regulatory body. A system to analyse human errors with respect to human caused and environment caused is being developed. The input data for this analysis is obtained from Safety Related Unusual Occurrence reports received by the regulatory body. The regulatory requirement for submission of these reports include first information report (by telex, telephone etc) within 24 hours of the incident and detailed report within 20 days. The detailed report amongst other information also contains information with respect to the cause of the incident. These reports are discussed at various levels and an attempt is made to identify the root cause. (author). 3 figs, 1 tab

  17. Estimation of distance error by fuzzy set theory required for strength determination of HDR 192Ir brachytherapy sources

    International Nuclear Information System (INIS)

    Verification of the strength of high dose rate (HDR) 192Ir brachytherapy sources on receipt from the vendor is an important component of institutional quality assurance program. Either reference air-kerma rate (RAKR) or air-kerma strength (AKS) is the recommended quantity to specify the strength of gamma-emitting brachytherapy sources. The use of Farmer-type cylindrical ionization chamber of sensitive volume 0.6 cm3 is one of the recommended methods for measuring RAKR of HDR 192Ir brachytherapy sources. While using the cylindrical chamber method, it is required to determine the positioning error of the ionization chamber with respect to the source which is called the distance error. An attempt has been made to apply the fuzzy set theory to estimate the subjective uncertainty associated with the distance error. A simplified approach of applying this fuzzy set theory has been proposed in the quantification of uncertainty associated with the distance error. In order to express the uncertainty in the framework of fuzzy sets, the uncertainty index was estimated and was found to be within 2.5%, which further indicates that the possibility of error in measuring such distance may be of this order. It is observed that the relative distance li estimated by analytical method and fuzzy set theoretic approach are consistent with each other. The crisp values of li estimated using analytical method lie within the bounds computed using fuzzy set theory. This indicates that li values estimated using analytical methods are within 2.5% uncertainty. This value of uncertainty in distance measurement should be incorporated in the uncertainty budget, while estimating the expanded uncertainty in HDR 192Ir source strength measurement. (author)

  18. Estimation of distance error by fuzzy set theory required for strength determination of HDR (192)Ir brachytherapy sources.

    Science.gov (United States)

    Kumar, Sudhir; Datta, D; Sharma, S D; Chourasiya, G; Babu, D A R; Sharma, D N

    2014-04-01

    Verification of the strength of high dose rate (HDR) (192)Ir brachytherapy sources on receipt from the vendor is an important component of institutional quality assurance program. Either reference air-kerma rate (RAKR) or air-kerma strength (AKS) is the recommended quantity to specify the strength of gamma-emitting brachytherapy sources. The use of Farmer-type cylindrical ionization chamber of sensitive volume 0.6 cm(3) is one of the recommended methods for measuring RAKR of HDR (192)Ir brachytherapy sources. While using the cylindrical chamber method, it is required to determine the positioning error of the ionization chamber with respect to the source which is called the distance error. An attempt has been made to apply the fuzzy set theory to estimate the subjective uncertainty associated with the distance error. A simplified approach of applying this fuzzy set theory has been proposed in the quantification of uncertainty associated with the distance error. In order to express the uncertainty in the framework of fuzzy sets, the uncertainty index was estimated and was found to be within 2.5%, which further indicates that the possibility of error in measuring such distance may be of this order. It is observed that the relative distance li estimated by analytical method and fuzzy set theoretic approach are consistent with each other. The crisp values of li estimated using analytical method lie within the bounds computed using fuzzy set theory. This indicates that li values estimated using analytical methods are within 2.5% uncertainty. This value of uncertainty in distance measurement should be incorporated in the uncertainty budget, while estimating the expanded uncertainty in HDR (192)Ir source strength measurement. PMID:24872605

  19. Estimation of distance error by fuzzy set theory required for strength determination of HDR 192Ir brachytherapy sources

    Science.gov (United States)

    Kumar, Sudhir; Datta, D.; Sharma, S. D.; Chourasiya, G.; Babu, D. A. R.; Sharma, D. N.

    2014-01-01

    Verification of the strength of high dose rate (HDR) 192Ir brachytherapy sources on receipt from the vendor is an important component of institutional quality assurance program. Either reference air-kerma rate (RAKR) or air-kerma strength (AKS) is the recommended quantity to specify the strength of gamma-emitting brachytherapy sources. The use of Farmer-type cylindrical ionization chamber of sensitive volume 0.6 cm3 is one of the recommended methods for measuring RAKR of HDR 192Ir brachytherapy sources. While using the cylindrical chamber method, it is required to determine the positioning error of the ionization chamber with respect to the source which is called the distance error. An attempt has been made to apply the fuzzy set theory to estimate the subjective uncertainty associated with the distance error. A simplified approach of applying this fuzzy set theory has been proposed in the quantification of uncertainty associated with the distance error. In order to express the uncertainty in the framework of fuzzy sets, the uncertainty index was estimated and was found to be within 2.5%, which further indicates that the possibility of error in measuring such distance may be of this order. It is observed that the relative distance li estimated by analytical method and fuzzy set theoretic approach are consistent with each other. The crisp values of li estimated using analytical method lie within the bounds computed using fuzzy set theory. This indicates that li values estimated using analytical methods are within 2.5% uncertainty. This value of uncertainty in distance measurement should be incorporated in the uncertainty budget, while estimating the expanded uncertainty in HDR 192Ir source strength measurement. PMID:24872605

  20. Human Errors and Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, A. S.

    Human errors are divided in two groups. The first group contains human errors, which effect the reliability directly. The second group contains human errors, which will not directly effect the reliability of the structure. The methodology used to estimate so-called reliability distributions on...... basis of reliability profiles for bridges without human errors are extended to include bridges with human errors. The first rehabilitation distributions for bridges without and with human errors are combined into a joint first rehabilitation distribution. The methodology presented is illustrated for...

  1. Game Design Principles based on Human Error

    Directory of Open Access Journals (Sweden)

    Guilherme Zaffari

    2016-03-01

    Full Text Available This paper displays the result of the authors’ research regarding to the incorporation of Human Error, through design principles, to video game design. In a general way, designers must consider Human Error factors throughout video game interface development; however, when related to its core design, adaptations are in need, since challenge is an important factor for fun and under the perspective of Human Error, challenge can be considered as a flaw in the system. The research utilized Human Error classifications, data triangulation via predictive human error analysis, and the expanded flow theory to allow the design of a set of principles in order to match the design of playful challenges with the principles of Human Error. From the results, it was possible to conclude that the application of Human Error in game design has a positive effect on player experience, allowing it to interact only with errors associated with the intended aesthetics of the game.

  2. Human factors evaluation of remote afterloading brachytherapy. Supporting analyses of human-system interfaces, procedures and practices, training and organizational practices and policies. Volume 3

    International Nuclear Information System (INIS)

    A human factors project on the use of nuclear by-product material to treat cancer using remotely operated afterloaders was undertaken by the Nuclear Regulatory Commission. The purpose of the project was to identify factors that contribute to human error in the system for remote afterloading brachytherapy (RAB). This report documents the findings from the second, third, fourth, and fifth phases of the project, which involved detailed analyses of four major aspects of the RAB system linked to human error: human-system interfaces; procedures and practices; training practices and policies; and organizational practices and policies, respectively. Findings based on these analyses provided factual and conceptual support for the final phase of this project, which identified factors leading to human error in RAB. The impact of those factors on RAB performance was then evaluated and prioritized in terms of safety significance, and alternative approaches for resolving safety significant problems were identified and evaluated

  3. Human factors evaluation of remote afterloading brachytherapy. Supporting analyses of human-system interfaces, procedures and practices, training and organizational practices and policies. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    Callan, J.R.; Kelly, R.T.; Quinn, M.L. [Pacific Science & Engineering Group, San Diego, CA (United States)] [and others

    1995-07-01

    A human factors project on the use of nuclear by-product material to treat cancer using remotely operated afterloaders was undertaken by the Nuclear Regulatory Commission. The purpose of the project was to identify factors that contribute to human error in the system for remote afterloading brachytherapy (RAB). This report documents the findings from the second, third, fourth, and fifth phases of the project, which involved detailed analyses of four major aspects of the RAB system linked to human error: human-system interfaces; procedures and practices; training practices and policies; and organizational practices and policies, respectively. Findings based on these analyses provided factual and conceptual support for the final phase of this project, which identified factors leading to human error in RAB. The impact of those factors on RAB performance was then evaluated and prioritized in terms of safety significance, and alternative approaches for resolving safety significant problems were identified and evaluated.

  4. Time-resolved in vivo luminescence dosimetry for online error detection in pulsed dose-rate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Claus E.; Nielsen, Soeren Kynde; Lindegaard, Jacob Christian; Tanderup, Kari [Radiation Research Division, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, DK-4000 Roskilde (Denmark); Department of Medical Physics, Aarhus University Hospital, DK-8000 Aarhus C (Denmark); Department of Oncology, Aarhus University Hospital, DK-8000 Aarhus C (Denmark); Department of Medical Physics, Aarhus University Hospital, DK-8000 Aarhus C (Denmark)

    2009-11-15

    Purpose: The purpose of this study is to present and evaluate a dose-verification protocol for pulsed dose-rate (PDR) brachytherapy based on in vivo time-resolved (1 s time resolution) fiber-coupled luminescence dosimetry. Methods: Five cervix cancer patients undergoing PDR brachytherapy (Varian GammaMed Plus with {sup 192}Ir) were monitored. The treatments comprised from 10 to 50 pulses (1 pulse/h) delivered by intracavitary/interstitial applicators (tandem-ring systems and/or needles). For each patient, one or two dosimetry probes were placed directly in or close to the tumor region using stainless steel or titanium needles. Each dosimeter probe consisted of a small aluminum oxide crystal attached to an optical fiber cable (1 mm outer diameter) that could guide radioluminescence (RL) and optically stimulated luminescence (OSL) from the crystal to special readout instrumentation. Positioning uncertainty and hypothetical dose-delivery errors (interchanged guide tubes or applicator movements from {+-}5 to {+-}15 mm) were simulated in software in order to assess the ability of the system to detect errors. Results: For three of the patients, the authors found no significant differences (P>0.01) for comparisons between in vivo measurements and calculated reference values at the level of dose per dwell position, dose per applicator, or total dose per pulse. The standard deviations of the dose per pulse were less than 3%, indicating a stable dose delivery and a highly stable geometry of applicators and dosimeter probes during the treatments. For the two other patients, the authors noted significant deviations for three individual pulses and for one dosimeter probe. These deviations could have been due to applicator movement during the treatment and one incorrectly positioned dosimeter probe, respectively. Computer simulations showed that the likelihood of detecting a pair of interchanged guide tubes increased by a factor of 10 or more for the considered patients when

  5. A qualitative description of human error

    International Nuclear Information System (INIS)

    The human error has an important contribution to risk of reactor operation. The insight and analytical model are main parts in human reliability analysis. It consists of the concept of human error, the nature, the mechanism of generation, the classification and human performance influence factors. On the operating reactor the human error is defined as the task-human-machine mismatch. The human error event is focused on the erroneous action and the unfavored result. From the time limitation of performing a task, the operation is divided into time-limited and time-opened. The HCR (human cognitive reliability) model is suited for only time-limited. The basic cognitive process consists of the information gathering, cognition/thinking, decision making and action. The human erroneous action may be generated in any stage of this process. The more natural ways to classify human errors are presented. The human performance influence factors including personal, organizational and environmental factors are also listed

  6. Human error classification and data collection

    International Nuclear Information System (INIS)

    Analysis of human error data requires human error classification. As the human factors/reliability subject has developed so too has the topic of human error classification. The classifications vary considerably depending on whether it has been developed from a theoretical psychological approach to understanding human behavior or error, or whether it has been based on an empirical practical approach. This latter approach is often adopted by nuclear power plants that need to make practical improvements as soon as possible. This document will review aspects of human error classification and data collection in order to show where potential improvements could be made. It will attempt to show why there are problems with human error classification and data collection schemes and that these problems will not be easy to resolve. The Annex of this document contains the papers presented at the meeting. A separate abstract was prepared for each of these 12 papers. Refs, figs and tabs

  7. Adaptive error detection for HDR/PDR brachytherapy: Guidance for decision making during real-time in vivo point dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Kertzscher, Gustavo, E-mail: guke@dtu.dk; Andersen, Claus E., E-mail: clan@dtu.dk [Centre for Nuclear Technologies, Technical University of Denmark, DTU Nutech, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Tanderup, Kari, E-mail: karitand@rm.dk [Department of Oncology, Aarhus University Hospital and Institute of Clinical Medicine, Aarhus University, Norrebrogade 44, DK-8000 Aarhus (Denmark)

    2014-05-15

    Purpose: This study presents an adaptive error detection algorithm (AEDA) for real-timein vivo point dosimetry during high dose rate (HDR) or pulsed dose rate (PDR) brachytherapy (BT) where the error identification, in contrast to existing approaches, does not depend on an a priori reconstruction of the dosimeter position. Instead, the treatment is judged based on dose rate comparisons between measurements and calculations of the most viable dosimeter position provided by the AEDA in a data driven approach. As a result, the AEDA compensates for false error cases related to systematic effects of the dosimeter position reconstruction. Given its nearly exclusive dependence on stable dosimeter positioning, the AEDA allows for a substantially simplified and time efficient real-time in vivo BT dosimetry implementation. Methods: In the event of a measured potential treatment error, the AEDA proposes the most viable dosimeter position out of alternatives to the original reconstruction by means of a data driven matching procedure between dose rate distributions. If measured dose rates do not differ significantly from the most viable alternative, the initial error indication may be attributed to a mispositioned or misreconstructed dosimeter (false error). However, if the error declaration persists, no viable dosimeter position can be found to explain the error, hence the discrepancy is more likely to originate from a misplaced or misreconstructed source applicator or from erroneously connected source guide tubes (true error). Results: The AEDA applied on twoin vivo dosimetry implementations for pulsed dose rate BT demonstrated that the AEDA correctly described effects responsible for initial error indications. The AEDA was able to correctly identify the major part of all permutations of simulated guide tube swap errors and simulated shifts of individual needles from the original reconstruction. Unidentified errors corresponded to scenarios where the dosimeter position was

  8. Adaptive error detection for HDR/PDR brachytherapy: Guidance for decision making during real-time in vivo point dosimetry

    International Nuclear Information System (INIS)

    Purpose: This study presents an adaptive error detection algorithm (AEDA) for real-timein vivo point dosimetry during high dose rate (HDR) or pulsed dose rate (PDR) brachytherapy (BT) where the error identification, in contrast to existing approaches, does not depend on an a priori reconstruction of the dosimeter position. Instead, the treatment is judged based on dose rate comparisons between measurements and calculations of the most viable dosimeter position provided by the AEDA in a data driven approach. As a result, the AEDA compensates for false error cases related to systematic effects of the dosimeter position reconstruction. Given its nearly exclusive dependence on stable dosimeter positioning, the AEDA allows for a substantially simplified and time efficient real-time in vivo BT dosimetry implementation. Methods: In the event of a measured potential treatment error, the AEDA proposes the most viable dosimeter position out of alternatives to the original reconstruction by means of a data driven matching procedure between dose rate distributions. If measured dose rates do not differ significantly from the most viable alternative, the initial error indication may be attributed to a mispositioned or misreconstructed dosimeter (false error). However, if the error declaration persists, no viable dosimeter position can be found to explain the error, hence the discrepancy is more likely to originate from a misplaced or misreconstructed source applicator or from erroneously connected source guide tubes (true error). Results: The AEDA applied on twoin vivo dosimetry implementations for pulsed dose rate BT demonstrated that the AEDA correctly described effects responsible for initial error indications. The AEDA was able to correctly identify the major part of all permutations of simulated guide tube swap errors and simulated shifts of individual needles from the original reconstruction. Unidentified errors corresponded to scenarios where the dosimeter position was

  9. Game Design Principles based on Human Error

    OpenAIRE

    Guilherme Zaffari; André Luiz Battaiola

    2016-01-01

    This paper displays the result of the authors’ research regarding to the incorporation of Human Error, through design principles, to video game design. In a general way, designers must consider Human Error factors throughout video game interface development; however, when related to its core design, adaptations are in need, since challenge is an important factor for fun and under the perspective of Human Error, challenge can be considered as a flaw in the system. The research u...

  10. Verification and source-position error analysis of film reconstruction techniques used in the brachytherapy planning systems

    International Nuclear Information System (INIS)

    A method was presented that employs standard linac QA tools to verify the accuracy of film reconstruction algorithms used in the brachytherapy planning system. Verification of reconstruction techniques is important as suggested in the ESTRO booklet 8: ''The institution should verify the full process of any reconstruction technique employed clinically.'' Error modeling was also performed to analyze seed-position errors. The ''isocentric beam checker'' device was used in this work. It has a two-dimensional array of steel balls embedded on its surface. The checker was placed on the simulator couch with its center ball coincident with the simulator isocenter, and one axis of its cross marks parallel to the axis of gantry rotation. The gantry of the simulator was rotated to make the checker behave like a three-dimensional array of balls. Three algorithms used in the ABACUS treatment planning system: orthogonal film, 2-films-with-variable-angle, and 3-films-with-variable-angle were tested. After exposing and digitizing the films, the position of each steel ball on the checker was reconstructed and compared to its true position, which can be accurately calculated. The results showed that the error is dependent on the object-isocenter distance, but not the magnification of the object. The averaged errors were less than 1 mm within the tolerance level defined by Roueet al. [''The EQUAL-ESTRO audit on geometric reconstruction techniques in brachytherapy,'' Radiother. Oncol. 78, 78-83 (2006)]. However, according to the error modeling, the theoretical error would be greater than 2 mm if the objects were located more than 20 cm away from the isocenter with a 0.5 deg. reading error of the gantry and collimator angles. Thus, in addition to carefully performing the QA of the gantry and collimator angle indicators, it is suggested that the patient, together with the applicators or seeds inside, should be placed close to the isocenter as much as possible. This method could be used

  11. Notes on human error analysis and prediction

    International Nuclear Information System (INIS)

    The notes comprise an introductory discussion of the role of human error analysis and prediction in industrial risk analysis. Following this introduction, different classes of human errors and role in industrial systems are mentioned. Problems related to the prediction of human behaviour in reliability and safety analysis are formulated and ''criteria for analyzability'' which must be met by industrial systems so that a systematic analysis can be performed are suggested. The appendices contain illustrative case stories and a review of human error reports for the task of equipment calibration and testing as found in the US Licensee Event Reports. (author)

  12. Real-time in vivo dosimetry and error detection during afterloading brachytherapy

    DEFF Research Database (Denmark)

    Kertzscher Schwencke, Gustavo Adolfo Vladimir

    Image guided afterloaded brachytherapy (BT) allows for conformal and patient specific radiotherapy (RT) treatments against cancer, where high dose concentrations are administered to the tumor volume and small doses to organs at risk (OARs). In afterloaded BT, ionizing radiation is delivered by...... cervical cancer at the Aarhus University Hospital. The tools and methods developed for the implementation targeted requirements for accurate IVD and the demands for a time-efficient and straightforward clinical approach. The performance of all developments was explored based on IVD results for 20 PDR BT...... means of a radionuclide attached to a source chain that is placed inside source catheters implanted in the target region. As for any RT treatment modality, BT treatments are subject to discrepancies between the delivered and planned treatments. Given the localized and high dose concentration near BT...

  13. Understanding Human Error Based on Automated Analyses

    Data.gov (United States)

    National Aeronautics and Space Administration — This is a report on a continuing study of automated analyses of experiential textual reports to gain insight into the causal factors of human errors in aviation...

  14. Human Error Analysis by Fuzzy-Set

    International Nuclear Information System (INIS)

    In conventional HRA the probability of Error is treated as a single and exact value through constructing even tree, but in this moment the Fuzzy-Set Theory is used. Fuzzy set theory treat the probability of error as a plausibility which illustrate a linguistic variable. Most parameter or variable in human engineering been defined verbal good, fairly good, worst etc. Which describe a range of any value of probability. For example this analysis is quantified the human error in calibration task, and the probability of miscalibration is very low

  15. Can the human error concept be transcended?

    International Nuclear Information System (INIS)

    For risk analysts and human factors specialists, the analysis of human errors has become a major objective. The occurrence of very serious, though extremely rare, accidents in the industrial and transportation sectors and the recurrence of minor incidents with no critical effect on the systems seem to nourish the technical community's concern and to reinforce the tendency to focus on human error. A vision of human factors that focuses too much on individual human error and the corresponding cause analyses is overmechanistic. It ignores dynamically interacting multicausal factors that may result in serious incidents or even accidents. Any attempt to retracing these incidents or accidents a posteriori most often involves preconceptions and implicit hypotheses, the most typical being the knowledge of the incident or accident itself

  16. A new human eye model for ophthalmic brachytherapy dosimetry

    International Nuclear Information System (INIS)

    The present work proposes a new mathematical eye model for ophthalmic brachytherapy dosimetry. This new model includes detailed description of internal structures that were not treated in previous works, allowing dose determination in different regions of the eye for a more adequate clinical analysis. Dose calculations were determined with the MCNP-4C Monte Carlo particle transport code running n parallel environment using PVM. The Amersham CKA4 ophthalmic applicator has been chosen and the depth dose distribution has been determined and compared to those provide by the manufacturer. The results have shown excellent agreement. Besides, absorbed dose values due to both 125I seeds and 60Co plaques were obtained for each one of the different structures which compose the eye model and can give relevant information in eventual clinical analyses. (authors)

  17. A chance to avoid mistakes human error

    International Nuclear Information System (INIS)

    Trying to give an answer to the lack of public information in the industry, in relationship with the different tools that are managed in the nuclear industry for minimizing the human error, a group of workers from different sections of the St. Maria de Garona NPP (Quality Assurance/ Organization and Human Factors) decided to embark on a challenging and exciting project: 'Write a book collecting all the knowledge accumulated during their daily activities, very often during lecture time of external information received from different organizations within the nuclear industry (INPO, WANO...), but also visiting different NPP's, maintaining meetings and participating in training courses related de Human and Organizational Factors'. Main objective of the book is presenting to the industry in general, the different tools that are used and fostered in the nuclear industry, in a practical way. In this way, the assimilation and implementation in others industries could be possible and achievable in and efficient context. One year of work, and our project is a reality. We have presented and abstract during the last Spanish Nuclear Society meeting in Sevilla, last October...and the best, the book is into the market for everybody in web-site: www.bubok.com. The book is structured in the following areas: 'Errare humanum est': Trying to present what is the human error to the reader, its origin and the different barriers. The message is that the reader see the error like something continuously present in our lives... even more frequently than we think. Studying its origin can be established aimed at barriers to avoid or at least minimize it. 'Error's bitter face': Shows the possible consequences of human errors. What better that presenting real experiences that have occurred in the industry. In the book, accidents in the nuclear industry, like Tree Mile Island NPP, Chernobyl NPP, and incidents like Davis Besse NPP in the past, helps to the reader to make a reflection about the

  18. Simulator data on human error probabilities

    International Nuclear Information System (INIS)

    Analysis of operator errors on NPP simulators is being used to determine Human Error Probabilities (HEP) for task elements defined in NUREG/CR-1278. Simulator data tapes from research conducted by EPRI and ORNL are being analyzed for operator error rates. The tapes collected, using Performance Measurement System software developed for EPRI, contain a history of all operator manipulations during simulated casualties. Analysis yields a time history or Operational Sequence Diagram and a manipulation summary, both stored in computer data files. Data searches yield information on operator errors of omission and commission. This work experimentally determined HEP's for Probabilistic Risk Assessment calculations. It is the only practical experimental source of this data to date

  19. Influence of trace elements in human tissue in low-energy photon brachytherapy dosimetry

    International Nuclear Information System (INIS)

    The aim of this paper is to determine the dosimetric impact of trace elements in human tissues for low-energy photon sources used in brachytherapy. Monte Carlo dose calculations were used to investigate the dosimetric effect of trace elements present in normal or cancerous human tissues. The effect of individual traces (atomic number Z = 11–30) was studied in soft tissue irradiated by low-energy brachytherapy sources. Three other tissue types (prostate, adipose and mammary gland) were also simulated with varying trace concentrations to quantify the contribution of each trace to the dose distribution. The dose differences between cancerous and healthy prostate tissues were calculated in single- and multi-source geometries. The presence of traces in a tissue produces a difference in the dose distribution that is dependent on Z and the concentration of the trace. Low-Z traces (Na) have a negligible effect (3%). There is a potentially significant difference in the dose distribution between cancerous and healthy prostate tissues (4%) and even larger if compared to the trace-free composition (15%) in both single- and multi-sourced geometries. Trace elements have a non-negligible (up to 8% in prostate D90) effect on the dose in tissues irradiated with low-energy photon sources. This study underlines the need for further investigation into accurate determination of the trace composition of tissues associated with low-energy brachytherapy. Alternatively, trace elements could be incorporated as a source of uncertainty in dose calculations. (paper)

  20. The cost of human error intervention

    International Nuclear Information System (INIS)

    DOE has directed that cost-benefit analyses be conducted as part of the review process for all new DOE orders. This new policy will have the effect of ensuring that DOE analysts can justify the implementation costs of the orders that they develop. We would like to argue that a cost-benefit analysis is merely one phase of a complete risk management program -- one that would more than likely start with a probabilistic risk assessment. The safety community defines risk as the probability of failure times the severity of consequence. An engineering definition of failure can be considered in terms of physical performance, as in mean-time-between-failure; or, it can be thought of in terms of human performance, as in probability of human error. The severity of consequence of a failure can be measured along any one of a number of dimensions -- economic, political, or social. Clearly, an analysis along one dimension cannot be directly compared to another but, a set of cost-benefit analyses, based on a series of cost-dimensions, can be extremely useful to managers who must prioritize their resources. Over the last two years, DOE has been developing a series of human factors orders, directed a lowering the probability of human error -- or at least changing the distribution of those errors. The following discussion presents a series of cost-benefit analyses using historical events in the nuclear industry. However, we would first like to discuss some of the analytic cautions that must be considered when we deal with human error

  1. The cost of human error intervention

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, C.T.; Banks, W.W.; Jones, E.D.

    1994-03-01

    DOE has directed that cost-benefit analyses be conducted as part of the review process for all new DOE orders. This new policy will have the effect of ensuring that DOE analysts can justify the implementation costs of the orders that they develop. We would like to argue that a cost-benefit analysis is merely one phase of a complete risk management program -- one that would more than likely start with a probabilistic risk assessment. The safety community defines risk as the probability of failure times the severity of consequence. An engineering definition of failure can be considered in terms of physical performance, as in mean-time-between-failure; or, it can be thought of in terms of human performance, as in probability of human error. The severity of consequence of a failure can be measured along any one of a number of dimensions -- economic, political, or social. Clearly, an analysis along one dimension cannot be directly compared to another but, a set of cost-benefit analyses, based on a series of cost-dimensions, can be extremely useful to managers who must prioritize their resources. Over the last two years, DOE has been developing a series of human factors orders, directed a lowering the probability of human error -- or at least changing the distribution of those errors. The following discussion presents a series of cost-benefit analyses using historical events in the nuclear industry. However, we would first like to discuss some of the analytic cautions that must be considered when we deal with human error.

  2. Human error mitigation initiative (HEMI) : summary report.

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, Susan M.; Ramos, M. Victoria; Wenner, Caren A.; Brannon, Nathan Gregory

    2004-11-01

    Despite continuing efforts to apply existing hazard analysis methods and comply with requirements, human errors persist across the nuclear weapons complex. Due to a number of factors, current retroactive and proactive methods to understand and minimize human error are highly subjective, inconsistent in numerous dimensions, and are cumbersome to characterize as thorough. An alternative and proposed method begins with leveraging historical data to understand what the systemic issues are and where resources need to be brought to bear proactively to minimize the risk of future occurrences. An illustrative analysis was performed using existing incident databases specific to Pantex weapons operations indicating systemic issues associated with operating procedures that undergo notably less development rigor relative to other task elements such as tooling and process flow. Future recommended steps to improve the objectivity, consistency, and thoroughness of hazard analysis and mitigation were delineated.

  3. An evaluation of a Low-Dose-Rate (LDR) brachytherapy procedure using a systems engineering & error analysis methodology for health care (SEABH) - (SAVE)

    LENUS (Irish Health Repository)

    Chadwick, Liam

    2012-03-12

    Health Care Failure Modes and Effects Analysis (HFMEA®) is an established tool for risk assessment in health care. A number of deficiencies have been identified in the method. A new method called Systems and Error Analysis Bundle for Health Care (SEABH) was developed to address these deficiencies. SEABH has been applied to a number of medical processes as part of its validation and testing. One of these, Low Dose Rate (LDR) prostate Brachytherapy is reported in this paper. The case study supported the validity of SEABH with respect to its capacity to address the weaknesses of (HFMEA®).

  4. Perancangan Fasilitas Kerja untuk Mereduksi Human Error

    Directory of Open Access Journals (Sweden)

    Harmein Nasution

    2012-01-01

    Full Text Available Work equipments and environment which are not design ergonomically can cause physical exhaustion to the workers. As a result of that physical exhaustion, many defects in the production lines can happen due to human error and also cause musculoskeletal complaints. To overcome, those effects, we occupied methods for analyzing the workers posture based on the SNQ (Standard Nordic Questionnaire, plibel, QEC (Quick Exposure Check and biomechanism. Moreover, we applied those methods for designing rolling machines and grip egrek ergono-mically, so that the defects on those production lines can be minimized.

  5. Human errors, countermeasures for their prevention and evaluation

    International Nuclear Information System (INIS)

    The accidents originated in human errors have occurred as ever in recent large accidents such as the TMI accident and the Chernobyl accident. The proportion of the accidents originated in human errors is unexpectedly high, therefore, the reliability and safety of hardware are improved hereafter, but the improvement of human reliability cannot be expected. Human errors arise by the difference between the function required for men and the function actually accomplished by men, and the results exert some adverse effect to systems. Human errors are classified into design error, manufacture error, operation error, maintenance error, checkup error and general handling error. In terms of behavior, human errors are classified into forget to do, fail to do, do that must not be done, mistake in order and do at improper time. The factors in human error occurrence are circumstantial factor, personal factor and stress factor. As the method of analyzing and evaluating human errors, system engineering method such as probabilistic risk assessment is used. The technique for human error rate prediction, the method for human cognitive reliability, confusion matrix and SLIM-MAUD are also used. (K.I.)

  6. A technique for human error analysis (ATHEANA)

    International Nuclear Information System (INIS)

    Probabilistic risk assessment (PRA) has become an important tool in the nuclear power industry, both for the Nuclear Regulatory Commission (NRC) and the operating utilities. Human reliability analysis (HRA) is a critical element of PRA; however, limitations in the analysis of human actions in PRAs have long been recognized as a constraint when using PRA. A multidisciplinary HRA framework has been developed with the objective of providing a structured approach for analyzing operating experience and understanding nuclear plant safety, human error, and the underlying factors that affect them. The concepts of the framework have matured into a rudimentary working HRA method. A trial application of the method has demonstrated that it is possible to identify potentially significant human failure events from actual operating experience which are not generally included in current PRAs, as well as to identify associated performance shaping factors and plant conditions that have an observable impact on the frequency of core damage. A general process was developed, albeit in preliminary form, that addresses the iterative steps of defining human failure events and estimating their probabilities using search schemes. Additionally, a knowledge- base was developed which describes the links between performance shaping factors and resulting unsafe actions

  7. A technique for human error analysis (ATHEANA)

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, S.E.; Ramey-Smith, A.M.; Wreathall, J.; Parry, G.W. [and others

    1996-05-01

    Probabilistic risk assessment (PRA) has become an important tool in the nuclear power industry, both for the Nuclear Regulatory Commission (NRC) and the operating utilities. Human reliability analysis (HRA) is a critical element of PRA; however, limitations in the analysis of human actions in PRAs have long been recognized as a constraint when using PRA. A multidisciplinary HRA framework has been developed with the objective of providing a structured approach for analyzing operating experience and understanding nuclear plant safety, human error, and the underlying factors that affect them. The concepts of the framework have matured into a rudimentary working HRA method. A trial application of the method has demonstrated that it is possible to identify potentially significant human failure events from actual operating experience which are not generally included in current PRAs, as well as to identify associated performance shaping factors and plant conditions that have an observable impact on the frequency of core damage. A general process was developed, albeit in preliminary form, that addresses the iterative steps of defining human failure events and estimating their probabilities using search schemes. Additionally, a knowledge- base was developed which describes the links between performance shaping factors and resulting unsafe actions.

  8. Sensitivity of low energy brachytherapy Monte Carlo dose calculations to uncertainties in human tissue composition

    International Nuclear Information System (INIS)

    Purpose: The objective of this work is to assess the sensitivity of Monte Carlo (MC) dose calculations to uncertainties in human tissue composition for a range of low photon energy brachytherapy sources: 125I, 103Pd, 131Cs, and an electronic brachytherapy source (EBS). The low energy photons emitted by these sources make the dosimetry sensitive to variations in tissue atomic number due to the dominance of the photoelectric effect. This work reports dose to a small mass of water in medium Dw,m as opposed to dose to a small mass of medium in medium Dm,m. Methods: Mean adipose, mammary gland, and breast tissues (as uniform mixture of the aforementioned tissues) are investigated as well as compositions corresponding to one standard deviation from the mean. Prostate mean compositions from three different literature sources are also investigated. Three sets of MC simulations are performed with the GEANT4 code: (1) Dose calculations for idealized TG-43-like spherical geometries using point sources. Radial dose profiles obtained in different media are compared to assess the influence of compositional uncertainties. (2) Dose calculations for four clinical prostate LDR brachytherapy permanent seed implants using 125I seeds (Model 2301, Best Medical, Springfield, VA). The effect of varying the prostate composition in the planning target volume (PTV) is investigated by comparing PTV D90 values. (3) Dose calculations for four clinical breast LDR brachytherapy permanent seed implants using 103Pd seeds (Model 2335, Best Medical). The effects of varying the adipose/gland ratio in the PTV and of varying the elemental composition of adipose and gland within one standard deviation of the assumed mean composition are investigated by comparing PTV D90 values. For (2) and (3), the influence of using the mass density from CT scans instead of unit mass density is also assessed. Results: Results from simulation (1) show that variations in the mean compositions of tissues affect low energy

  9. Minimizing the human error rate by understanding the relationship between skill and rule-based errors

    International Nuclear Information System (INIS)

    The rate of equipment failure caused events at nuclear power plants has been decreasing steadily, while the rate of human error caused events has not been decreasing nearly as rapidly. Using the skill-rule-knowledge based model of Rasmussen, many day-to-day operations are classified as skill-based actions and, consequently most of the errors in day-to-day operations are skill-based errors. In order to reduce the rate of skill-based errors, rules (procedures, forms, and checklists) have been developed. However, the increasing complexity and redundancy in rules leads to an increasing rate of errors in making rules and in carrying them out. To minimize the error rate, a compromise must be chosen. This article suggests a practical method to understand why human error caused events are not decreasing as rapidly as equipment caused events, and how to develop effective actions to reduce the human error rate

  10. Human reliability, error, and human factors in power generation

    CERN Document Server

    Dhillon, B S

    2014-01-01

    Human reliability, error, and human factors in the area of power generation have been receiving increasing attention in recent years. Each year billions of dollars are spent in the area of power generation to design, construct/manufacture, operate, and maintain various types of power systems around the globe, and such systems often fail due to human error. This book compiles various recent results and data into one volume, and eliminates the need to consult many diverse sources to obtain vital information.  It enables potential readers to delve deeper into a specific area, providing the source of most of the material presented in references at the end of each chapter. Examples along with solutions are also provided at appropriate places, and there are numerous problems for testing the reader’s comprehension.  Chapters cover a broad range of topics, including general methods for performing human reliability and error analysis in power plants, specific human reliability analysis methods for nuclear power pl...

  11. Errors

    International Nuclear Information System (INIS)

    Data indicates that about one half of all errors are skill based. Yet, most of the emphasis is focused on correcting rule and knowledge based errors leading to more programs, supervision, and training. None of this corrective action applies to the 'mental lapse' error. Skill based errors are usually committed in performing a routine and familiar task. Workers went to the wrong unit or component, or wrong something. Too often some of these errors result in reactor scrams, turbine trips, or other unwanted actuation. The workers do not need more programs, supervision, or training. They need to know when they are vulnerable and they need to know how to think. Self check can prevent errors, but only if it is practiced intellectually, and with commitment. Skill based errors are usually the result of using habits and senses instead of using our intellect. Even human factors can play a role in the cause of an error on a routine task. Personal injury also, is usually an error. Sometimes they are called accidents, but most accidents are the result of inappropriate actions. Whether we can explain it or not, cause and effect were there. A proper attitude toward risk, and a proper attitude toward danger is requisite to avoiding injury. Many personal injuries can be avoided just by attitude. Errors, based on personal experience and interviews, examines the reasons for the 'mental lapse' errors, and why some of us become injured. The paper offers corrective action without more programs, supervision, and training. It does ask you to think differently. (author)

  12. An Human Reliability Analysis to Identify Human Error Mechanisms for Reducing the Risks Associated with Human Errors in a Main Control Room of the SMART

    International Nuclear Information System (INIS)

    The research results are summarized as followed: (1) The task analysis performed on the EOGs of the SMART MMIS identified seven different human error mechanisms: Perception Error, Decision Error, Control-Identification Error, Control-Selection Error, Control-Execution Error, Communication Error, and Extraneous Error. The human error mechanisms includes 48 different human error types. 2) The design requirements were proposed to prevent 48 different possible human errors while running the HSI of SMART. 3) Sixteen different human errors were found for the SC designed by KAERI. Fifty six PSFs were also identified influencing the initiation of a human error mechanism. 4) Human factors design requirements were developed to hinder the human error mechanisms. CHED in KHU proposed a design alternative of the SC which took into account the human factors design requirements previously identified. 5) An human error quantification technique was applied to compare the CHED design with that the KAERI's in terms of the probabilities of the human errors caused by each design. The comparison showed that the CHD design was more effective than the KAERI's to reduce the human error probability from 0.0108 to 0.00004. It meant that 96.3% of the human error probability in the KAERI's was prevented by introducing the human factors design recommendations on the SC design

  13. Human factors and medication errors: a case study.

    Science.gov (United States)

    Gluyas, Heather; Morrison, Paul

    2014-12-15

    Human beings are error prone. A significant component of human error is flaws inherent in human cognitive processes, which are exacerbated by situations in which the individual making the error is distracted, stressed or overloaded, or does not have sufficient knowledge to undertake an action correctly. The scientific discipline of human factors deals with environmental, organisational and job factors, as well as human and individual characteristics, which influence behaviour at work in a way that potentially gives rise to human error. This article discusses how cognitive processing is related to medication errors. The case of a coronial inquest into the death of a nursing home resident is used to highlight the way people think and process information, and how such thinking and processing may lead to medication errors. PMID:25492790

  14. Analysis of Employee's Survey for Preventing Human-Errors

    International Nuclear Information System (INIS)

    Human errors in nuclear power plant can cause large and small events or incidents. These events or incidents are one of main contributors of reactor trip and might threaten the safety of nuclear plants. To prevent human-errors, KHNP(nuclear power plants) introduced 'Human-error prevention techniques' and have applied the techniques to main parts such as plant operation, operation support, and maintenance and engineering. This paper proposes the methods to prevent and reduce human-errors in nuclear power plants through analyzing survey results which includes the utilization of the human-error prevention techniques and the employees' awareness of preventing human-errors. With regard to human-error prevention, this survey analysis presented the status of the human-error prevention techniques and the employees' awareness of preventing human-errors. Employees' understanding and utilization of the techniques was generally high and training level of employee and training effect on actual works were in good condition. Also, employees answered that the root causes of human-error were due to working environment including tight process, manpower shortage, and excessive mission rather than personal negligence or lack of personal knowledge. Consideration of working environment is certainly needed. At the present time, based on analyzing this survey, the best methods of preventing human-error are personal equipment, training/education substantiality, private mental health check before starting work, prohibit of multiple task performing, compliance with procedures, and enhancement of job site review. However, the most important and basic things for preventing human-error are interests of workers and organizational atmosphere such as communication between managers and workers, and communication between employees and bosses

  15. HUMAN ERROR - MANAGING THE BLAME FOR INCREASING ORGANISATIONAL POLICE PERFORMANCE

    OpenAIRE

    ADRIAN-CONSTANTIN ACHIM

    2012-01-01

    Every organisation that deals with hazards and people on a daily basis faces a simply and very profound choice: either it manages human error or human error will manage the organisation, always with great cost and often in great danger. Managers fail to understand that the biggest risk they are running into is to interfere with human error. There are also other risks to be dealt with, like trading or currency risk, but human error is really the big one. It has fantastic financial consequence....

  16. Influence of organizational culture on human error

    International Nuclear Information System (INIS)

    Much has been written in contemporary business literature during the last decade describing the role that corporate culture plays in virtually every aspect of a firm's success. In 1990 Kotter and Heskett wrote, open-quotes We found that firms with cultures that emphasized all of the key managerial constituencies (customers, stockholders, and employees) and leadership from managers at all levels out-performed firms that did not have those cultural traits by a huge margin. Over an eleven year period, the former increased revenues by an average of 682 percent versus 166 percent for the latter, expanded their workforce by 282 percent versus 36 percent, grew their stock prices by 901 percent versus 74 percent, and improved their net incomes by 756 percent versus 1 percent.close quotes Since the mid-1980s, several electric utilities have documented their efforts to undertake strategic culture change. In almost every case, these efforts have yielded dramatic improvements in the open-quotes bottom-lineclose quotes operational and financial results (e.g., Western Resources, Arizona Public Service, San Diego Gas ampersand Electric, and Electricity Trust of South Australia). Given the body of evidence that indicates a relationship between high-performing organizational culture and the financial and business success of a firm, Pennsylvania Power ampersand Light Company undertook a study to identify the relationship between organizational culture and the frequency, severity, and nature of human error at the Susquehanna Steam Electric Station. The underlying proposition for this asssessment is that organizational culture is an independent variable that transforms external events into organizational performance

  17. Human error - Risk factor in operating heavy water production facilities

    International Nuclear Information System (INIS)

    Continued increasing of the operating security of heavy water production facilities was and continues to be a basic preoccupation of the reliability specialists. According to statistical records about 20-30% of the failures occurred in such installations are directly or indirectly related to human errors. These are caused mainly by incorrect actions, maintenance errors, incorrect reading out of instrument indications. Not all the human errors have an impact on the system. A human error can be remedied before the undesirable consequences occur. Treating the human performances in probabilistic analytical studies provides the possibility of evaluating the human error contribution to the occurrence of event sequences. This work presents the possibility of utilizing probabilistic methods (event trees, failure trees) to identify solutions of improving the human reliability as far as the aspect of minimizing the risks in industrial installation operation is concerned. Also, different types of human errors were defined as well as the causes leading to committing mistakes, while, as technique for evaluating the human reliability, the method of decision tree analysis is presented. Exemplification for application of the method of human error analysis was made on the basis of operational data from the heavy water production pilot plant at Valcea, Romania. As initiation event for the accident situation the event of steam supply failure was considered. The contribution of human errors was analyzed for the accident sequence with the most serious consequences

  18. The Detection of Human Spreadsheet Errors by Humans versus Inspection (Auditing) Software

    CERN Document Server

    Aurigemma, Salvatore

    2010-01-01

    Previous spreadsheet inspection experiments have had human subjects look for seeded errors in spreadsheets. In this study, subjects attempted to find errors in human-developed spreadsheets to avoid the potential artifacts created by error seeding. Human subject success rates were compared to the successful rates for error-flagging by spreadsheet static analysis tools (SSATs) applied to the same spreadsheets. The human error detection results were comparable to those of studies using error seeding. However, Excel Error Check and Spreadsheet Professional were almost useless for correctly flagging natural (human) errors in this study.

  19. The analysis of human errors in nuclear power plant operation

    International Nuclear Information System (INIS)

    There are basically three different method known to approach human factors in the NPP-operation: - probabilistic error analysis; - analysis of human errors in real plant incidents; - job task analysis. Analysis of human errors occurring during operation and job analysis can be easily converted to operational improvements. From the analysis of human errors and errors' causes and, on the other hand, from the analysis of possible problems, it is possible to came to a derivation of requirements either for modifications of existing working systems or for the design of a new nuclear power plant. Of great importance is to have an established classification system for the error analysis in such a way that requirements can be derived by a set of elements of a matrix. (authors)

  20. The probability and the management of human error

    International Nuclear Information System (INIS)

    Embedded within modern technological systems, human error is the largest, and indeed dominant contributor to accident cause. The consequences dominate the risk profiles for nuclear power and for many other technologies. We need to quantify the probability of human error for the system as an integral contribution within the overall system failure, as it is generally not separable or predictable for actual events. We also need to provide a means to manage and effectively reduce the failure (error) rate. The fact that humans learn from their mistakes allows a new determination of the dynamic probability and human failure (error) rate in technological systems. The result is consistent with and derived from the available world data for modern technological systems. Comparisons are made to actual data from large technological systems and recent catastrophes. Best estimate values and relationships can be derived for both the human error rate, and for the probability. We describe the potential for new approaches to the management of human error and safety indicators, based on the principles of error state exclusion and of the systematic effect of learning. A new equation is given for the probability of human error (λ) that combines the influences of early inexperience, learning from experience (ε) and stochastic occurrences with having a finite minimum rate, this equation is λ 5.10-5 + ((1/ε) - 5.10-5) exp(-3*ε). The future failure rate is entirely determined by the experience: thus the past defines the future

  1. Identifying afterloading PDR and HDR brachytherapy errors using real-time fiber-coupled Al2O3:C dosimetry and a novel statistical error decision criterion

    DEFF Research Database (Denmark)

    Kertzscher, Gustavo; Andersen, Claus Erik; Siebert, Frank-André;

    2011-01-01

    conditions, and (2) test a new statistical error decision concept based on full uncertainty analysis. Materials and methodsPhantom studies of two gynecological cancer PDR and one prostate cancer HDR patient treatment plans were performed using tandem ring applicators or interstitial needles. Imposed...... advantage of a statistical error criterion....

  2. Development of A Human Error Analysis Procedure for Emergency Tasks

    International Nuclear Information System (INIS)

    It has been criticized that conventional human reliability analysis (HRA) methodologies are mainly focused on the quantification of human error probability (HEP) that an operator fails to perform a required task in a specific situation on the progression of an accident (Dougherty, 1990; Hollnagel, 1998). Generally, in the conventional HRA, the situation in which a task is required is identified on the event tree (ET) or fault tree (FT) of the probabilistic safety assessment (PSA). Many HRA practitioners and risk analysts (Kirwan, 1994; Parry, 1995; Julius et al, 1995; Hollnagel, 2000) have raised the need on the inclusion of various error types (or modes) including EOCs and analysis of specific error context (error causes and performance influencing factors) inducing such error modes. In order to complement the insufficiently treated aspect of the HRA, we are developing a human error analysis (HEA) procedure so that it may help analysts identify probable error modes and their possibilities for a given task or a situation. The developed HEA procedure is composed of two modules. The first module is a flowchart for the identification of error analysis items by cognitive function and for the selection of corresponding error analysis procedure. The second module is composed of the HEA procedures in which detailed error analyses are conducted. The HEA procedure is focused on the prediction of probable error modes (including EOOs and EOCs) considering task context for a situation where a task is required to perform. But, the framework is being extended to the analysis of error possibility of EOCs that can deteriorate the plant safety by operators' inappropriate interventions. Section 2 describes the framework to the analysis of error possibilities, and Section 3 presents the basic structure of the developed HEA procedure. In Section 4, results of case applications to emergency tasks are introduced. A human error analysis (HEA) procedure was developed in order to help

  3. Human Errors and Learnability Evaluation of Authentication System

    OpenAIRE

    Khan, Mohammad Ali; Nasir, Majid

    2011-01-01

    Usability studies are important in today’s context. However, the increased security level of authentication systems is reducing the usability level. Thus, to provide secured but yet usable authentication systems is a challenge for researchers to solve till now. Learnability and human errors are influential factors of the usability of authentication systems. There are not many specific studies on the learnability and human errors concentrating on authentication systems. The authors’ aim of thi...

  4. Prevention of human errors in nuclear power stations

    International Nuclear Information System (INIS)

    It is indispensable to decrease human errors as far as possible in view of the importance of nuclear power generation for Japan. From the viewpoint like this, the Central Research Institute of Electric Power Industry organized Human Factor Research Center in 1987, and the research on the prevention of human errors in nuclear power stations has been advanced together with electric power companies. For initial five years, the research centering around individual human behavior was advanced, and the establishment of the technique for the analysis of the cause and the plan of countermeasures on the occurred accidents and troubles from the aspect of human factors, the development of human behavior prediction system, the collection of the data on the state of research regarding human factors, the proposal of the concrete supporting technology for reducing human errors in maintenance works, the development of the technique for determining the probability of trouble occurrence, the development of the equipment for measuring and analyzing human visual sense, behavior and physiology, and the proposal of the technology for supporting the formation of knowledge and education system were carried out. In the second five-year period to 1996, the team errors in operation and maintenance, the development of a man-machine simulator, the practical use of the concrete supporting technology and so on are taken up. The human behavior prediction system is explained. (K.I.)

  5. Avoiding Human Error in Mission Operations: Cassini Flight Experience

    Science.gov (United States)

    Burk, Thomas A.

    2012-01-01

    Operating spacecraft is a never-ending challenge and the risk of human error is ever- present. Many missions have been significantly affected by human error on the part of ground controllers. The Cassini mission at Saturn has not been immune to human error, but Cassini operations engineers use tools and follow processes that find and correct most human errors before they reach the spacecraft. What is needed are skilled engineers with good technical knowledge, good interpersonal communications, quality ground software, regular peer reviews, up-to-date procedures, as well as careful attention to detail and the discipline to test and verify all commands that will be sent to the spacecraft. Two areas of special concern are changes to flight software and response to in-flight anomalies. The Cassini team has a lot of practical experience in all these areas and they have found that well-trained engineers with good tools who follow clear procedures can catch most errors before they get into command sequences to be sent to the spacecraft. Finally, having a robust and fault-tolerant spacecraft that allows ground controllers excellent visibility of its condition is the most important way to ensure human error does not compromise the mission.

  6. Operator error and emotions. Operator error and emotions - a major cause of human failure

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, B.K. [Human Factors Practical Incorporated (Canada); Bradley, M. [Univ. of New Brunswick, Saint John, New Brunswick (Canada); Artiss, W.G. [Human Factors Practical (Canada)

    2000-07-01

    This paper proposes the idea that a large proportion of the incidents attributed to operator and maintenance error in a nuclear or industrial plant are actually founded in our human emotions. Basic psychological theory of emotions is briefly presented and then the authors present situations and instances that can cause emotions to swell and lead to operator and maintenance error. Since emotional information is not recorded in industrial incident reports, the challenge is extended to industry, to review incident source documents for cases of emotional involvement and to develop means to collect emotion related information in future root cause analysis investigations. Training must then be provided to operators and maintainers to enable them to know one's emotions, manage emotions, motivate one's self, recognize emotions in others and handle relationships. Effective training will reduce the instances of human error based in emotions and enable a cooperative, productive environment in which to work. (author)

  7. Operator error and emotions. Operator error and emotions - a major cause of human failure

    International Nuclear Information System (INIS)

    This paper proposes the idea that a large proportion of the incidents attributed to operator and maintenance error in a nuclear or industrial plant are actually founded in our human emotions. Basic psychological theory of emotions is briefly presented and then the authors present situations and instances that can cause emotions to swell and lead to operator and maintenance error. Since emotional information is not recorded in industrial incident reports, the challenge is extended to industry, to review incident source documents for cases of emotional involvement and to develop means to collect emotion related information in future root cause analysis investigations. Training must then be provided to operators and maintainers to enable them to know one's emotions, manage emotions, motivate one's self, recognize emotions in others and handle relationships. Effective training will reduce the instances of human error based in emotions and enable a cooperative, productive environment in which to work. (author)

  8. [Meat and human health: excess and errors].

    Science.gov (United States)

    Lecerf, Jean-Michel

    2011-11-01

    Many studies have examined the influence of meat consumption on human health. Meat eaters have a higher body mass index and more weight gain than vegetarians. The risk of type 2 diabetes has also been linked to high meat consumption. However, the statistical correlations with these metabolic disorders are weak. There is inconsistent evidence of a higher cardiovascular risk. A link between high meat consumption and cancer, particularly colorectal cancer, has been observed in nearly all epidemiological studies. Some studies have also shown a link with breast, prostate and lung cancer. The mode of cooking could be partly En 2 responsible for this effect, due for example to heterocyclic aromatic amines production euro during grilling and intensive cooking. Advice is given. PMID:22844742

  9. Applications of human error analysis to aviation and space operations

    International Nuclear Information System (INIS)

    For the past several years at the Idaho National Engineering and Environmental Laboratory (INEEL) we have been working to apply methods of human error analysis to the design of complex systems. We have focused on adapting human reliability analysis (HRA) methods that were developed for Probabilistic Safety Assessment (PSA) for application to system design. We are developing methods so that human errors can be systematically identified during system design, the potential consequences of each error can be assessed, and potential corrective actions (e.g. changes to system design or procedures) can be identified. These applications lead to different requirements when compared with HR.As performed as part of a PSA. For example, because the analysis will begin early during the design stage, the methods must be usable when only partial design information is available. In addition, the ability to perform numerous ''what if'' analyses to identify and compare multiple design alternatives is essential. Finally, since the goals of such human error analyses focus on proactive design changes rather than the estimate of failure probabilities for PRA, there is more emphasis on qualitative evaluations of error relationships and causal factors than on quantitative estimates of error frequency. The primary vehicle we have used to develop and apply these methods has been a series of prqjects sponsored by the National Aeronautics and Space Administration (NASA) to apply human error analysis to aviation operations. The first NASA-sponsored project had the goal to evaluate human errors caused by advanced cockpit automation. Our next aviation project focused on the development of methods and tools to apply human error analysis to the design of commercial aircraft. This project was performed by a consortium comprised of INEEL, NASA, and Boeing Commercial Airplane Group. The focus of the project was aircraft design and procedures that could lead to human errors during airplane maintenance

  10. Learning common lessons and checkpoints form human error incidents. Maintenance

    International Nuclear Information System (INIS)

    CRIEPI has been conducting detailed and structured analyses of all human error incidents collected from Japanese Licensee Event Reports using J-HPES (Japanese version of HPES) as an analysis method. Results obtained by the analyses have been stored in J-HPES database. This paper described the process to analyze J-HPES data concerning maintenance systematically to extract problems identified in the process of error action and checkpoints for preventing errors. Human error actions of these J-HPES data are classified by viewpoints of error mode and work type. As to each of these error categories, problems are extracted based on J-HPES causal relation charts in following three viewpoints: acts at workplace, activities, and preconditions of job. Moreover, checkpoints for preventing errors are developed referring proposed countermeasures in J-HPES database. In order to share these results, we started to issue 4-pages booklets 'Catch the Point' periodically. In future, based on these results, we will publish a teaching material. We also have a plan to store the contents of Catch the Point in a database, which facilitate users to find necessary checkpoints and hazards before they start their activities. (author)

  11. Advanced MMIS Toward Substantial Reduction in Human Errors in NPPs

    International Nuclear Information System (INIS)

    This paper aims to give an overview of the methods to inherently prevent human errors and to effectively mitigate the consequences of such errors by securing defense-in-depth during plant management through the advanced man-machine interface system (MMIS). It is needless to stress the significance of human error reduction during an accident in nuclear power plants (NPPs). Unexpected shutdowns caused by human errors not only threaten nuclear safety but also make public acceptance of nuclear power extremely lower. We have to recognize there must be the possibility of human errors occurring since humans are not essentially perfect particularly under stressful conditions. However, we have the opportunity to improve such a situation through advanced information and communication technologies on the basis of lessons learned from our experiences. As important lessons, authors explained key issues associated with automation, man-machine interface, operator support systems, and procedures. Upon this investigation, we outlined the concept and technical factors to develop advanced automation, operation and maintenance support systems, and computer-based procedures using wired/wireless technology. It should be noted that the ultimate responsibility of nuclear safety obviously belongs to humans not to machines. Therefore, safety culture including education and training, which is a kind of organizational factor, should be emphasized as well. In regard to safety culture for human error reduction, several issues that we are facing these days were described. We expect the ideas of the advanced MMIS proposed in this paper to lead in the future direction of related researches and finally supplement the safety of NPPs

  12. Quality assurance and human error effects on the structural safety

    International Nuclear Information System (INIS)

    Statistical surveys show that the frequency of failure of structures is much larger than that expected by the codes. Evidence exists that human errors (especially during the design process) is the main cause for the difference between the failure probability admitted by codes and the reality. In this paper, the attenuation of human error effects using tools of quality assurance is analyzed. In particular, the importance of the independent design review is highlighted, and different approaches are discussed. The experience from the Atucha II project, as well as the USA and German practice on independent design review, are summarized. (Author)

  13. Prostate brachytherapy

    Science.gov (United States)

    Implant therapy - prostate cancer; Radioactive seed placement; Internal radiation therapy - prostate; High dose radiation (HDR) ... Brachytherapy takes 30 minutes or more, depending on the type of therapy you have. Before the procedure, ...

  14. Interactive analysis of human error factors in NPP operation events

    International Nuclear Information System (INIS)

    Interactive of human error factors in NPP operation events were introduced, and 645 WANO operation event reports from 1999 to 2008 were analyzed, among which 432 were found relative to human errors. After classifying these errors with the Root Causes or Causal Factors, and then applying SPSS for correlation analysis,we concluded: (1) Personnel work practices are restricted by many factors. Forming a good personnel work practices is a systematic work which need supports in many aspects. (2)Verbal communications,personnel work practices, man-machine interface and written procedures and documents play great roles. They are four interaction factors which often come in bundle. If some improvements need to be made on one of them,synchronous measures are also necessary for the others.(3) Management direction and decision process, which are related to management,have a significant interaction with personnel factors. (authors)

  15. A Simulator for Human Error Probability Analysis (SHERPA)

    International Nuclear Information System (INIS)

    A new Human Reliability Analysis (HRA) method is presented in this paper. The Simulator for Human Error Probability Analysis (SHERPA) model provides a theoretical framework that exploits the advantages of the simulation tools and the traditional HRA methods in order to model human behaviour and to predict the error probability for a given scenario in every kind of industrial system. Human reliability is estimated as function of the performed task, the Performance Shaping Factors (PSF) and the time worked, with the purpose of considering how reliability depends not only on the task and working context, but also on the time that the operator has already spent on the work. The model is able to estimate human reliability; to assess the effects due to different human reliability levels through evaluation of tasks performed more or less correctly; and to assess the impact of context via PSFs. SHERPA also provides the possibility of determining the optimal configuration of breaks. Through a methodology that uses assessments of an economic nature, it allows identification of the conditions required for the suspension of work in the shift for the operator's psychophysical recovery and then for the restoration of acceptable values of reliability. - Highlights: • We propose a new method for Human Reliability Analysis called SHERPA. • SHERPA is able to model human behaviour and to predict the error probability. • Human reliability is function of task done, influencing factors and time worked. • SHERPA exploits benefits of the simulation tools and the traditional HRA methods. • SHERPA is implemented as a simulation template enable to assess human reliability

  16. THERP and HEART integrated methodology for human error assessment

    Science.gov (United States)

    Castiglia, Francesco; Giardina, Mariarosa; Tomarchio, Elio

    2015-11-01

    THERP and HEART integrated methodology is proposed to investigate accident scenarios that involve operator errors during high-dose-rate (HDR) treatments. The new approach has been modified on the basis of fuzzy set concept with the aim of prioritizing an exhaustive list of erroneous tasks that can lead to patient radiological overexposures. The results allow for the identification of human errors that are necessary to achieve a better understanding of health hazards in the radiotherapy treatment process, so that it can be properly monitored and appropriately managed.

  17. Effects of digital human-machine interface characteristics on human error in nuclear power plants

    International Nuclear Information System (INIS)

    In order to identify the effects of digital human-machine interface characteristics on human error in nuclear power plants, the new characteristics of digital human-machine interface are identified by comparing with the traditional analog control systems in the aspects of the information display, user interface interaction and management, control systems, alarm systems and procedures system, and the negative effects of digital human-machine interface characteristics on human error are identified by field research and interviewing with operators such as increased cognitive load and workload, mode confusion, loss of situation awareness. As to the adverse effects related above, the corresponding prevention and control measures of human errors are provided to support the prevention and minimization of human errors and the optimization of human-machine interface design. (authors)

  18. Human error: An essential problem of nuclear power plants

    International Nuclear Information System (INIS)

    The author first defines the part played by man in the nuclear power plant and then deals in more detail with the structure of his valse behavior in tactical and strategic repect. The dicussion of tactical errors and their avoidance is follwed by a report on the actual state of plant technology and possible improvements. Subsequently a study of the strategic errors including the conclusion to be drawn until now (joint between plant and man, personal selection and education) is made. If the joints between man and machine are designed according and physiological strenghts and weaknesses of man are fully realized and taken into account human errors not be essential problem in nuclear power plant. (GL)

  19. Human Errors - A Taxonomy for Describing Human Malfunction in Industrial Installations

    DEFF Research Database (Denmark)

    Rasmussen, J.

    1982-01-01

    This paper describes the definition and the characteristics of human errors. Different types of human behavior are classified, and their relation to different error mechanisms are analyzed. The effect of conditioning factors related to affective, motivating aspects of the work situation as well as...

  20. Identification of failure sequences sensitive to human error

    International Nuclear Information System (INIS)

    This report prepared by the participants of the technical committee meeting on ''Identification of Failure Sequences Sensitive to Human Error'' addresses the subjects discussed during the meeting and the conclusions reached by the committee. Chapter 1 reviews the INSAG recommendations and the main elements of the IAEA Programme in the area of human element. In Chapter 2 the role of human actions in nuclear power plants safety from insights of operational experience is reviewed. Chapter 3 is concerned with the relationship between probabilistic safety assessment and human performance associated with severe accident sequences. Chapter 4 addresses the role of simulators in view of training for accident conditions. Chapter 5 presents the conclusions and future trends. The seven papers presented by members of this technical committee are also included in this technical document. A separate abstract was prepared for each of these papers

  1. Modelling the basic error tendencies of human operators

    International Nuclear Information System (INIS)

    The paper outlines the primary structural features of human cognition: a limited, serial workspace interacting with a parallel distributed knowledge base. It is argued that the essential computational features of human cognition - to be captured by an adequate operator model - reside in the mechanisms by which stored knowledge structures are selected and brought into play. Two such computational 'primitives' are identified: similarity-matching and frequency-gambling. These two retrieval heuristics, it is argued, shape both the overall character of human performance (i.e. its heavy reliance on pattern-matching) and its basic error tendencies ('strong-but-wrong' responses, confirmation, similarity and frequency biases, and cognitive 'lock-up'). The various features of human cognition are integrated with a dynamic operator model capable of being represented in software form. This computer model, when run repeatedly with a variety of problem configurations, should produce a distribution of behaviours which, in toto, simulate the general character of operator performance. (author)

  2. The development of a human eye model for ophthalmic iodine-125 brachytherapy dosimetry

    International Nuclear Information System (INIS)

    Full text: Radiotherapy is used to treat malign tumors. Radiotherapy is an alternative to enucleation in ocular tumors. However, the irradiation of ocular region can bring damages due high doses, mainly in the crystalline lens and in the bone tissue in growth phase. Brachytherapy instead of teletherapy looks for reducing doses in the crystalline lens and the adjacent tissues of the ocular globe (orbital region), minimizing side effects. Herein, some encapsulated radioisotopes in radioactive seeds applied to the ocular brachytherapy are available. Thus, a three-dimensional computational voxel model of the ocular region with its heterogeneous tissues, globe and adjacent tissues is developed. This computational model is used to simulate orbital irradiation with radioactive seeds positioned on the sclera surface through the MCNP5 code. The computational simulation allows evaluating how doses are spatially distributed in the orbital volume in treatments with the radioactive seeds of iodine-125. Therefore, the results allow comparing the spatial doses distribution obtained through the MCNP5 simulation for those two distinct types of radioactive seeds. Bench markets from literature validates the proposed simulations. (author)

  3. Glass microspheres for brachytherapy

    International Nuclear Information System (INIS)

    We developed the capacity to produce glass microspheres containing in their structure one or more radioactive isotopes useful for brachytherapy. We studied the various facts related with their production: (Rare earth) alumino silicate glass making, glass characterization, microspheres production, nuclear activation through (n,γ) nuclear reactions, mechanical characterization before and after irradiation. Corrosion tests in simulated human plasma and mechanical properties characterization were done before and after irradiation. (author)

  4. Human error probability quantification using fuzzy methodology in nuclear plants

    International Nuclear Information System (INIS)

    This work obtains Human Error Probability (HEP) estimates from operator's actions in response to emergency situations a hypothesis on Research Reactor IEA-R1 from IPEN. It was also obtained a Performance Shaping Factors (PSF) evaluation in order to classify them according to their influence level onto the operator's actions and to determine these PSF actual states over the plant. Both HEP estimation and PSF evaluation were done based on Specialists Evaluation using interviews and questionnaires. Specialists group was composed from selected IEA-R1 operators. Specialist's knowledge representation into linguistic variables and group evaluation values were obtained through Fuzzy Logic and Fuzzy Set Theory. HEP obtained values show good agreement with literature published data corroborating the proposed methodology as a good alternative to be used on Human Reliability Analysis (HRA). (author)

  5. A strategy for minimizing common mode human error in executing critical functions and tasks

    International Nuclear Information System (INIS)

    Human error in execution of critical functions and tasks can be costly. The Three Mile Island and the Chernobyl Accidents are examples of results from human error in the nuclear industry. There are similar errors that could no doubt be cited from other industries. This paper discusses a strategy to minimize common mode human error in the execution of critical functions and tasks. The strategy consists of the use of human redundancy, and also diversity in human cognitive behavior: skill-, rule-, and knowledge-based behavior. The authors contend that the use of diversity in human cognitive behavior is possible, and it minimizes common mode error

  6. A Human reliability analysis of post-accident human errors in the PSA of KSNP

    International Nuclear Information System (INIS)

    Korea Atomic Energy Research Institute, using the ASME PRA Standard, evaluated the PSA model of the Korea Standard Nuclear Power Plant (KSNP) and identified the items to be improved to enhance its quality. The new risk monitor PSA model for the KSNP of which quality was enhanced is called as PRiME-U3i. The evaluation results of human reliability analysis (HRA) of the post-accident human errors in the PSA model of the KSNP showed that 10 items among 19 items of supporting requirements for those in the ASME PRA Standard were identified as them to be improved. Thus, we newly carried out a HRA for post-accident human errors for the KSNP PSA model as the target of grading its quality above ASME PRA Standard Category I+. Following tasks were additionally major tasks performed in the HRA of post-accident human errors of PRiME-U3i compared with the previous PSA model of the KSNP: interviews with operators in the collection and review of input data need for the HRA, modeling of initial feed and bleed operation as human actions according to 5 initiating event groups, documentation of information of all the input and bases for the detailed quantifications using the quantification sheets The number of the re-estimated human errors of PRiME-U3i according to the Korea Standard HRA method is 92. Among them, the number of individual post-accident human errors is 55. The number of dependent post-accident human errors is 37. Modeling of one event for initial feed and bleed operation increase the CDF of PRiME-U3i by 13.58% compared with baseline CDF. The assessment results for the new HRA results of post-accident human errors of PRiME-U3i using the ASME PRA Standard show that above 80% items of its supporting requirements for post-accident human errors were graded as its Category II. Thus, this study results sufficiently meet the ASME PRA Standard Category I+. It is expected that the HRA results presented in this study will be greatly helpful to improve the PSA quality for the

  7. The Relationship between Human Operators' Psycho-physiological Condition and Human Errors in Nuclear Power Plants

    International Nuclear Information System (INIS)

    The safe operation of nuclear power plants (NPPs) is substantially dependent on the performance of the human operators who operate the systems. In this environment, human errors caused by inappropriate performance of operator have been considered to be critical since it may lead serious problems in the safety-critical plants. In order to provide meaningful insights to prevent human errors and enhance the human performance, operators' physiological conditions such as stress and workload have been investigated. Physiological measurements were considered as reliable tools to assess the stress and workload. T. Q. Tran et al. and J. B. Brooking et al pointed out that operators' workload can be assessed using eye tracking, galvanic skin response, electroencephalograms (EEGs), heart rate, respiration and other measurements. The purpose of this study is to investigate the effect of the human operators' tense level and knowledge level to the number of human errors. For this study, the experiments were conducted in the mimic of the main control rooms (MCR) in NPP. It utilized the compact nuclear simulator (CNS) which is modeled based on the three loop Pressurized Water Reactor, 993MWe, Kori unit 3 and 4 in Korea and the subjects were asked to follow the tasks described in the emergency operating procedures (EOP). During the simulation, three kinds of physiological measurement were utilized; Electrocardiogram (ECG), EEG and nose temperature. Also, subjects were divided into three groups based on their knowledge of the plant operation. The result shows that subjects who are tense make fewer errors. In addition, subjects who are in higher knowledge level tend to be tense and make fewer errors. For the ECG data, subjects who make fewer human errors tend to be located in higher tense level area of high SNS activity and low PSNS activity. The results of EEG data are also similar to ECG result. Beta power ratio of subjects who make fewer errors was higher. Since beta power ratio is

  8. Scaling prediction errors to reward variability benefits error-driven learning in humans

    OpenAIRE

    Kelly M J Diederen; Schultz, Wolfram

    2015-01-01

    Effective error-driven learning requires individuals to adapt learning to environmental reward variability. The adaptive mechanism may involve decays in learning rate across subsequent trials, as shown previously, and rescaling of reward prediction errors. The present study investigated the influence of prediction error scaling and, in particular, the consequences for learning performance. Participants explicitly predicted reward magnitudes that were drawn from different probability distribut...

  9. Quantification of the effects of dependence on human error probabilities

    International Nuclear Information System (INIS)

    In estimating the probabilities of human error in the performance of a series of tasks in a nuclear power plant, the situation-specific characteristics of the series must be considered. A critical factor not to be overlooked in this estimation is the dependence or independence that pertains to any of the several pairs of task performances. In discussing the quantification of the effects of dependence, the event tree symbology described will be used. In any series of tasks, the only dependence considered for quantification in this document will be that existing between the task of interest and the immediately preceeding task. Tasks performed earlier in the series may have some effect on the end task, but this effect is considered negligible

  10. Latent human error analysis and efficient improvement strategies by fuzzy TOPSIS in aviation maintenance tasks.

    Science.gov (United States)

    Chiu, Ming-Chuan; Hsieh, Min-Chih

    2016-05-01

    The purposes of this study were to develop a latent human error analysis process, to explore the factors of latent human error in aviation maintenance tasks, and to provide an efficient improvement strategy for addressing those errors. First, we used HFACS and RCA to define the error factors related to aviation maintenance tasks. Fuzzy TOPSIS with four criteria was applied to evaluate the error factors. Results show that 1) adverse physiological states, 2) physical/mental limitations, and 3) coordination, communication, and planning are the factors related to airline maintenance tasks that could be addressed easily and efficiently. This research establishes a new analytic process for investigating latent human error and provides a strategy for analyzing human error using fuzzy TOPSIS. Our analysis process complements shortages in existing methodologies by incorporating improvement efficiency, and it enhances the depth and broadness of human error analysis methodology. PMID:26851473

  11. A Conceptual Framework of Human Reliability Analysis for Execution Human Error in NPP Advanced MCRs

    International Nuclear Information System (INIS)

    The operation environment of Main Control Rooms (MCRs) in Nuclear Power Plants (NPPs) has changed with the adoption of new human-system interfaces that are based on computer-based technologies. The MCRs that include these digital and computer technologies, such as large display panels, computerized procedures, and soft controls, are called Advanced MCRs. Among the many features of Advanced MCRs, soft controls are a particularly important feature because the operation action in NPP Advanced MCRs is performed by soft control. Using soft controls such as mouse control, and touch screens, operators can select a specific screen, then choose the controller, and finally manipulate the given devices. Due to the different interfaces between soft control and hardwired conventional type control, different human error probabilities and a new Human Reliability Analysis (HRA) framework should be considered in the HRA for advanced MCRs. In other words, new human error modes should be considered for interface management tasks such as navigation tasks, and icon (device) selection tasks in monitors and a new framework of HRA method taking these newly generated human error modes into account should be considered. In this paper, a conceptual framework for a HRA method for the evaluation of soft control execution human error in advanced MCRs is suggested by analyzing soft control tasks

  12. A Conceptual Framework of Human Reliability Analysis for Execution Human Error in NPP Advanced MCRs

    Energy Technology Data Exchange (ETDEWEB)

    Jang, In Seok; Kim, Ar Ryum; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of); Jung, Won Dea [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-08-15

    The operation environment of Main Control Rooms (MCRs) in Nuclear Power Plants (NPPs) has changed with the adoption of new human-system interfaces that are based on computer-based technologies. The MCRs that include these digital and computer technologies, such as large display panels, computerized procedures, and soft controls, are called Advanced MCRs. Among the many features of Advanced MCRs, soft controls are a particularly important feature because the operation action in NPP Advanced MCRs is performed by soft control. Using soft controls such as mouse control, and touch screens, operators can select a specific screen, then choose the controller, and finally manipulate the given devices. Due to the different interfaces between soft control and hardwired conventional type control, different human error probabilities and a new Human Reliability Analysis (HRA) framework should be considered in the HRA for advanced MCRs. In other words, new human error modes should be considered for interface management tasks such as navigation tasks, and icon (device) selection tasks in monitors and a new framework of HRA method taking these newly generated human error modes into account should be considered. In this paper, a conceptual framework for a HRA method for the evaluation of soft control execution human error in advanced MCRs is suggested by analyzing soft control tasks.

  13. Findings from analysing and quantifying human error using current methods

    International Nuclear Information System (INIS)

    In human reliability analysis (HRA), the scarcity of data means that, at best, judgement must be applied to transfer to the domain of the analysis what data are available for similar tasks. In particular for the quantification of tasks involving decisions, the analyst has to choose among quantification approaches that all depend to a significant degree on expert judgement. The use of expert judgement can be made more reliable by eliciting relative judgements rather than absolute judgements. These approaches, which are based on multiple criterion decision theory, focus on ranking the tasks to be analysed by difficulty. While these approaches remedy at least partially the poor performance of experts in the estimation of probabilities, they nevertheless require the calibration of the relative scale on which the actions are ranked in order to obtain the probabilities of interest. This paper presents some results from a comparison of some current HRA methods performed in the frame of a study of SLIM calibration options. The HRA quantification methods THERP, HEART, and INTENT were applied to derive calibration human error probabilities for two groups of operator actions. (author)

  14. Encoding of Sensory Prediction Errors in the Human Cerebellum

    OpenAIRE

    Schlerf, John; Richard B. Ivry; Diedrichsen, Jörn

    2012-01-01

    A central tenet of motor neuroscience is that the cerebellum learns from sensory prediction errors. Surprisingly, neuroimaging studies have not revealed definitive signatures of error processing in the cerebellum. Furthermore, neurophysiologic studies suggest an asymmetry, such that the cerebellum may encode errors arising from unexpected sensory events, but not errors reflecting the omission of expected stimuli. We conducted an imaging study to compare the cerebellar response to these two ty...

  15. Brachytherapy applications and techniques

    CERN Document Server

    Devlin, Phillip M

    2015-01-01

    Written by the foremost experts in the field, this volume is a comprehensive text and practical reference on contemporary brachytherapy. The book provides detailed, site-specific information on applications and techniques of brachytherapy in the head and neck, central nervous system, breast, thorax, gastrointestinal tract, and genitourinary tract, as well as on gynecologic brachytherapy, low dose rate and high dose rate sarcoma brachytherapy, vascular brachytherapy, and pediatric applications. The book thoroughly describes and compares the four major techniques used in brachytherapy-intraca

  16. A study of brachytherapy for intraocular tumor

    International Nuclear Information System (INIS)

    Our purpose of this study is to perform brachytherapy for intraocular tumor. The result were as followed. 1. Eye model was determined as a 25 mm diameter sphere. Ir-192 was considered the most appropriate as radioisotope for brachytherapy, because of the size, half, energy and availability. 2. Considering the biological response with human tissue and protection of exposed dose, we made the plaques with gold, of which size were 15 mm, 17 mm and 20 mm in diameter, and 1.5 mm in thickness. 3. Transmission factor of plaques are all 0.71 with TLD and film dosimetry at the surface of plaques and 0.45, 0.49 at 1.5 mm distance of surface, respectively. 4. As compared the measured data for the plaque with Ir-192 seeds to results of computer dose calculation model by Gary Luxton et al. and CAP-PLAN (Radiation Treatment Planning System), absorbed doses are within ±10% and distance deviations are within 0.4 mm. Maximum error is -11.3% and 0.8 mm, respectively. 7 figs, 2 tabs, 28 refs. (Author)

  17. Strengthening human-error management to improve the performance of safe operation of NPP

    International Nuclear Information System (INIS)

    With the fast development of nuclear technology, the technical preventative measures for human errors has been improved significantly. For many years, events that induced by human error still account a high percentage of total events occurred in NPPs. Aiming to improve the human performance, CNNC Nuclear Power Company (CNNP), together with its affiliated NPPs, developed a set of fleet-wide human error management guideline, training materials, handbooks, human error prevention tools, and accelerates the process of its implementation in NPPs. This paper is intended to introduce the practices adopted by CNNC with the purpose of common improvement of the operation performance of domestic NPPs. (author)

  18. Savannah River Site human error data base development for nonreactor nuclear facilities

    International Nuclear Information System (INIS)

    As part of an overall effort to upgrade and streamline methodologies for safety analyses of nonreactor nuclear facilities at the Savannah River Site (SRS), a human error data base has been developed and is presented in this report. The data base fulfills several needs of risk analysts supporting safety analysis report (SAR) development. First, it provides a single source for probabilities or rates for a wide variety of human errors associated with the SRS nonreactor nuclear facilities. Second, it provides a documented basis for human error probabilities or rates. And finally, it provides actual SRS-specific human error data to support many of the error probabilities or rates. Use of a single, documented reference source for human errors, supported by SRS-specific human error data, will improve the consistency and accuracy of human error modeling by SRS risk analysts. It is envisioned that SRS risk analysts will use this report as both a guide to identifying the types of human errors that may need to be included in risk models such as fault and event trees, and as a source for human error probabilities or rates. For each human error in this report, ffime different mean probabilities or rates are presented to cover a wide range of conditions and influencing factors. The ask analysts must decide which mean value is most appropriate for each particular application. If other types of human errors are needed for the risk models, the analyst must use other sources. Finally, if human enors are dominant in the quantified risk models (based on the values obtained fmm this report), then it may be appropriate to perform detailed human reliability analyses (HRAS) for the dominant events. This document does not provide guidance for such refined HRAS; in such cases experienced human reliability analysts should be involved

  19. Savannah River Site human error data base development for nonreactor nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Benhardt, H.C.; Held, J.E.; Olsen, L.M.; Vail, R.E. [Westinghouse Savannah River Co., Aiken, SC (United States); Eide, S.A. [Los Alamos Technical Associates, Inc., Albuquerque, NM (United States)

    1994-02-28

    As part of an overall effort to upgrade and streamline methodologies for safety analyses of nonreactor nuclear facilities at the Savannah River Site (SRS), a human error data base has been developed and is presented in this report. The data base fulfills several needs of risk analysts supporting safety analysis report (SAR) development. First, it provides a single source for probabilities or rates for a wide variety of human errors associated with the SRS nonreactor nuclear facilities. Second, it provides a documented basis for human error probabilities or rates. And finally, it provides actual SRS-specific human error data to support many of the error probabilities or rates. Use of a single, documented reference source for human errors, supported by SRS-specific human error data, will improve the consistency and accuracy of human error modeling by SRS risk analysts. It is envisioned that SRS risk analysts will use this report as both a guide to identifying the types of human errors that may need to be included in risk models such as fault and event trees, and as a source for human error probabilities or rates. For each human error in this report, ffime different mean probabilities or rates are presented to cover a wide range of conditions and influencing factors. The ask analysts must decide which mean value is most appropriate for each particular application. If other types of human errors are needed for the risk models, the analyst must use other sources. Finally, if human enors are dominant in the quantified risk models (based on the values obtained fmm this report), then it may be appropriate to perform detailed human reliability analyses (HRAS) for the dominant events. This document does not provide guidance for such refined HRAS; in such cases experienced human reliability analysts should be involved.

  20. Risk analysis of brachytherapy events

    International Nuclear Information System (INIS)

    For prevention radiological events it is necessary to identify hazardous situation and to analyse the nature of committed errors. Though the recommendation on the classification and prevention of radiological events: Radiological accidents has been prepared in the framework of Czech Society of Radiation Oncology, Biology and Physics and it was approved by Czech regulatory body (SONS) in 1999, only a few reports have been submitted up to now from brachytherapy practice. At the radiotherapy departments attention has been paid more likely to the problems of dominant teletherapy treatments. But in the two last decades the usage of brachytherapy methods has gradually increased because .nature of this treatment well as the possibilities of operating facility have been completely changed: new radionuclides of high activity are introduced and sophisticate afterloading systems controlled by computers are used. Consequently also the nature of errors, which can occurred in the clinical practice, has been changing. To determine the potentially hazardous parts of procedure the so-called 'process tree', which follows the flow of entire treatment process, has been created for most frequent type of applications. Marking the location of errors on the process tree indicates where failures occurred and accumulation of marks along branches show weak points in the process. Analysed data provide useful information to prevent medical events in brachytherapy .The results strength the requirements given in Recommendations of SONS and revealed the need for its amendment. They call especially for systematic registration of the events. (authors)

  1. AGAPE-ET for human error analysis of emergency tasks and its application

    International Nuclear Information System (INIS)

    The paper presents a proceduralised human reliability analysis (HRA) methodology, AGAPE-ET (A Guidance And Procedure for Human Error Analysis for Emergency Tasks), covering both qualitative error analysis and quantification of human error probability (HEP) of emergency tasks in nuclear power plants. The AGAPE-ET method is based on the simplified cognitive model. By each cognitive function, error causes or error-likely situations have been identified considering the characteristics of the performance of each cognitive function and influencing mechanism of the performance influencing factors (PIFs) on the cognitive function. Then, error analysis items have been determined from the identified error causes or error-likely situations and a human error analysis procedure based on the error analysis items is organised to help the analysts cue or guide overall human error analysis. The basic scheme for the quantification of HEP consists in the multiplication of the BHEP assigned by the error analysis item and the weight from the influencing factors decision tree (IFDT) constituted by cognitive function. The method can be characterised by the structured identification of the weak points of the task required to perform and the efficient analysis process that the analysts have only to carry out with the necessary cognitive functions. The paper also presents the application of AGAPE-ET to 31 nuclear emergency tasks and its results

  2. Oops, something is wrong - error detection and recovery for advanced human-robot-interaction

    OpenAIRE

    Spexard, Thorsten P.; Hanheide, Marc; Li, Shuyin; Wrede, Britta

    2008-01-01

    A matter of course for the researchers and developers of state-of-the-art technology for human-computer- or human-robot-interaction is to create not only systems that can precisely fulfill a certain task. They must provide a strong robustness against internal and external errors or user-dependent application errors. Especially when creating service robots for a variety of applications or robots for accompanying humans in everyday situations sufficient error robustness is crucial for acceptanc...

  3. Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

    OpenAIRE

    Samia de Freitas Brandao; Tarcisio Passos Ribeiro de Campos

    2013-01-01

    Objective Comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and Methods Simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted int...

  4. Human factors interventions to reduce human errors and improve productivity in maintenance tasks

    International Nuclear Information System (INIS)

    This paper describes work in progress to develop interventions to reduce human errors and increase maintenance productivity in nuclear power plants. The effort is part of a two-phased Human Factors research program being conducted jointly by the Central Research Institute of Electric Power Industry (CRIEPI) in Japan and the Electric Power Research Institute (EPRI) in the United States. The overall objective of this joint research program is to identify critical maintenance tasks and to develop, implement and evaluate interventions which have high potential for reducing human errors or increasing maintenance productivity. As a result of the Phase 1 effort, ten critical maintenance tasks were identified. For these tasks, over 25 candidate interventions were identified for potential development. After careful analysis, seven interventions were selected for development during Phase 2. This paper describes the methodology used to analyze and identify the most critical tasks, the process of identifying and developing selected interventions and some of the initial results. (author)

  5. Fuzzy Logic-Based Approach Identifying Criticality of Human Error Risk

    International Nuclear Information System (INIS)

    In the system reliability and safety assessment,the focuses are not only risk caused by hardware or software, but also risk caused by 'human error'. This paper considers the effects of risk of human error on system, and presents a new risk assessment model of human error based on fuzzy logic used to determine risk prioritization of human error. The method not only considers the human error probability, but also integrates the error-effect probability and consequence severity into the risk assessment model to satisfy the objective of probability safety assessment. At the same time,the method can model the complex system behavior to deal with subjective, vague and uncertain information or knowledge and it is more realistic than traditional method.A case example is presented to demonstrate the proposed approach. The results show that the method is practicable, reliable and valuable. (authors)

  6. A risk methodology to evaluate sensitvity of plant risk to human errors

    International Nuclear Information System (INIS)

    This paper presents an evaluation of sensitivity of plant risk parameters, namely the core melt frequency and the accident sequence frequencies, to the human errors involved in various aspects of nuclear power plant operations. Results are provided using the Oconee-3 Probabilistic Risk Assessment model as an example application of the risk methodology described herein. Sensitivity analyses in probabilistic risk assessment (PRA) involve three areas: (1) a determination of the set of input parameters; in this case, various categories of human errors signifying aspects of plant operation, (2) the range over which the input parameters vary, and (3) an assessment of the sensitivity of the plant risk parameters to the input parameters which, in this case, consist of all postulated human errors, or categories of human errors. The methodology presents a categorization scheme where human errors are categorized in terms of types of activity, location, personnel involved, etc., to relate the significance of sensitivity of risk parameters to specific aspects of human performance in the nuclear plant. Ranges of variability for human errors have been developed considering the various known causes of uncertainty in human error probability estimates in PRAs. The sensitivity of the risk parameters are assessed using the event/fault tree methodology of the PRA. The results of the risk-based sensitivity evaluation using the Oconee-3 PRA as an example show the quantitative impact on the plant risk level due to variations in human error probabilities. The relative effects of various human error categories and human error sorts within the categories are also presented to identify and characterize significant human errors for effective risk management in nuclear power plant operational activities. 8 refs., 10 figs., 4 tabs

  7. Investigations on human error hazards in recent unintended trip events of Korean nuclear power plants

    International Nuclear Information System (INIS)

    According to the Operational Performance Information System (OPIS) which has been operated to improve the public understanding by the KINS (Korea Institute of Nuclear Safety), unintended trip events by mainly human errors counted up to 38 cases (18.7%) from 2000 to 2011. Although the Nuclear Power Plant (NPP) industry in Korea has been making efforts to reduce the human errors which have largely contributed to trip events, the human error rate might keep increasing. Interestingly, digital based I and C systems is the one of the reduction factors of unintended reactor trips. Human errors, however, have occurred due to the digital based I and C systems because those systems require new or changed behaviors to the NPP operators. Therefore, it is necessary that the investigations of human errors consider a new methodology to find not only tangible behavior but also intangible behavior such as organizational behaviors. In this study we investigated human errors to find latent factors such as decisions and conditions in the all of the unintended reactor trip events during last dozen years. To find them, we applied the HFACS (Human Factors Analysis and Classification System) which is a commonly utilized tool for investigating human contributions to aviation accidents under a widespread evaluation scheme. The objective of this study is to find latent factors behind of human errors in nuclear reactor trip events. Therefore, a method to investigate unintended trip events by human errors and the results will be discussed in more detail

  8. Knowledge-base for the new human reliability analysis method, A Technique for Human Error Analysis (ATHEANA)

    International Nuclear Information System (INIS)

    This paper describes the knowledge base for the application of the new human reliability analysis (HRA) method, a ''A Technique for Human Error Analysis'' (ATHEANA). Since application of ATHEANA requires the identification of previously unmodeled human failure events, especially errors of commission, and associated error-forcing contexts (i.e., combinations of plant conditions and performance shaping factors), this knowledge base is an essential aid for the HRA analyst

  9. The treatment of commission errors in first generation human reliability analysis methods

    International Nuclear Information System (INIS)

    Human errors in human reliability analysis can be classified generically as errors of omission and commission errors. Omission errors are related to the omission of any human action that should have been performed, but does not occur. Errors of commission are those related to human actions that should not be performed, but which in fact are performed. Both involve specific types of cognitive error mechanisms, however, errors of commission are more difficult to model because they are characterized by non-anticipated actions that are performed instead of others that are omitted (omission errors) or are entered into an operational task without being part of the normal sequence of this task. The identification of actions that are not supposed to occur depends on the operational context that will influence or become easy certain unsafe actions of the operator depending on the operational performance of its parameters and variables. The survey of operational contexts and associated unsafe actions is a characteristic of second-generation models, unlike the first generation models. This paper discusses how first generation models can treat errors of commission in the steps of detection, diagnosis, decision-making and implementation, in the human information processing, particularly with the use of THERP tables of errors quantification. (author)

  10. The treatment of commission errors in first generation human reliability analysis methods

    Energy Technology Data Exchange (ETDEWEB)

    Alvarengga, Marco Antonio Bayout; Fonseca, Renato Alves da, E-mail: bayout@cnen.gov.b, E-mail: rfonseca@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN) Rio de Janeiro, RJ (Brazil); Melo, Paulo Fernando Frutuoso e, E-mail: frutuoso@nuclear.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear

    2011-07-01

    Human errors in human reliability analysis can be classified generically as errors of omission and commission errors. Omission errors are related to the omission of any human action that should have been performed, but does not occur. Errors of commission are those related to human actions that should not be performed, but which in fact are performed. Both involve specific types of cognitive error mechanisms, however, errors of commission are more difficult to model because they are characterized by non-anticipated actions that are performed instead of others that are omitted (omission errors) or are entered into an operational task without being part of the normal sequence of this task. The identification of actions that are not supposed to occur depends on the operational context that will influence or become easy certain unsafe actions of the operator depending on the operational performance of its parameters and variables. The survey of operational contexts and associated unsafe actions is a characteristic of second-generation models, unlike the first generation models. This paper discusses how first generation models can treat errors of commission in the steps of detection, diagnosis, decision-making and implementation, in the human information processing, particularly with the use of THERP tables of errors quantification. (author)

  11. Structured methods for identifying and correcting potential human errors in space operations

    Science.gov (United States)

    Nelson, William R.; Haney, Lon N.; Ostrom, Lee T.; Richards, Robert E.

    Human performance plays a significant role in the development and operation of any complex system, and human errors are significant contributors to degraded performance, incidents, and accidents for technologies as diverse as medical systems, commercial aircraft, offshore oil platforms, nuclear power plants, and space systems. To date, serious accidents attributed to human error have fortunately been rare in space operations. However, as flight rates go up and the duration of space missions increases, the accident rate could increase unless proactive action is taken to identify and correct potential human errors in space operations. The Idaho National Engineering and Environmental Laboratory (INEEL) has developed and applied structured methods of human error analysis to identify potential human errors, assess their effects on system performance, and develop strategies to prevent the errors or mitigate their consequences. These methods are being applied in NASA-sponsored programs to the domain of commercial aviation, focusing on airplane maintenance and air traffic management. The application of human error analysis to space operations could contribute to minimize the risks associated with human error in the design and operation of future space systems.

  12. Error-related EEG patterns during tactile human-machine interaction

    NARCIS (Netherlands)

    Lehne, M.; Ihme, K.; Brouwer, A.M.; Erp, J.B.F. van; Zander, T.O.

    2009-01-01

    Recently, the use of brain-computer interfaces (BCIs) has been extended from active control to passive detection of cognitive user states. These passive BCI systems can be especially useful for automatic error detection in human-machine systems by recording EEG potentials related to human error proc

  13. Quality of IT service delivery — Analysis and framework for human error prevention

    KAUST Repository

    Shwartz, L.

    2010-12-01

    In this paper, we address the problem of reducing the occurrence of Human Errors that cause service interruptions in IT Service Support and Delivery operations. Analysis of a large volume of service interruption records revealed that more than 21% of interruptions were caused by human error. We focus on Change Management, the process with the largest risk of human error, and identify the main instances of human errors as the 4 Wrongs: request, time, configuration item, and command. Analysis of change records revealed that the humanerror prevention by partial automation is highly relevant. We propose the HEP Framework, a framework for execution of IT Service Delivery operations that reduces human error by addressing the 4 Wrongs using content integration, contextualization of operation patterns, partial automation of command execution, and controlled access to resources.

  14. The recovery factors analysis of the human errors for research reactors

    International Nuclear Information System (INIS)

    The results of many Probabilistic Safety Assessment (PSA) studies show a very significant contribution of human errors to systems unavailability of the nuclear installations. The treatment of human interactions is considered one of the major limitations in the context of PSA. To identify those human actions that can have an effect on system reliability or availability applying the Human Reliability Analysis (HRA) is necessary. The recovery factors analysis of the human action is an important step in HRA. This paper presents how can be reduced the human errors probabilities (HEP) using those elements that have the capacity to recovery human error. The recovery factors modeling is marked to identify error likelihood situations or situations that conduct at development of the accident. This analysis is realized by THERP method. The necessary information was obtained from the operating experience of the research reactor TRIGA of the INR Pitesti. The required data were obtained from generic databases. (authors)

  15. The Human Bathtub: Safety and Risk Predictions Including the Dynamic Probability of Operator Errors

    International Nuclear Information System (INIS)

    Reactor safety and risk are dominated by the potential and major contribution for human error in the design, operation, control, management, regulation and maintenance of the plant, and hence to all accidents. Given the possibility of accidents and errors, now we need to determine the outcome (error) probability, or the chance of failure. Conventionally, reliability engineering is associated with the failure rate of components, or systems, or mechanisms, not of human beings in and interacting with a technological system. The probability of failure requires a prior knowledge of the total number of outcomes, which for any predictive purposes we do not know or have. Analysis of failure rates due to human error and the rate of learning allow a new determination of the dynamic human error rate in technological systems, consistent with and derived from the available world data. The basis for the analysis is the 'learning hypothesis' that humans learn from experience, and consequently the accumulated experience defines the failure rate. A new 'best' equation has been derived for the human error, outcome or failure rate, which allows for calculation and prediction of the probability of human error. We also provide comparisons to the empirical Weibull parameter fitting used in and by conventional reliability engineering and probabilistic safety analysis methods. These new analyses show that arbitrary Weibull fitting parameters and typical empirical hazard function techniques cannot be used to predict the dynamics of human errors and outcomes in the presence of learning. Comparisons of these new insights show agreement with human error data from the world's commercial airlines, the two shuttle failures, and from nuclear plant operator actions and transient control behavior observed in transients in both plants and simulators. The results demonstrate that the human error probability (HEP) is dynamic, and that it may be predicted using the learning hypothesis and the minimum

  16. Development and evaluation of a computer-aided system for analyzing human error in railway operations

    International Nuclear Information System (INIS)

    As human error has been recognized as one of the major contributors to accidents in safety-critical systems, there has been a strong need for techniques that can analyze human error effectively. Although many techniques have been developed so far, much room for improvement remains. As human error analysis is a cognitively demanding and time-consuming task, it is particularly necessary to develop a computerized system supporting this task. This paper presents a computer-aided system for analyzing human error in railway operations, called Computer-Aided System for Human Error Analysis and Reduction (CAS-HEAR). It supports analysts to find multiple levels of error causes and their causal relations by using predefined links between contextual factors and causal factors as well as links between causal factors. In addition, it is based on a complete accident model; hence, it helps analysts to conduct a thorough analysis without missing any important part of human error analysis. A prototype of CAS-HEAR was evaluated by nine field investigators from six railway organizations in Korea. Its overall usefulness in human error analysis was confirmed, although development of its simplified version and some modification of the contextual factors and causal factors are required in order to ensure its practical use.

  17. A methodology for collection and analysis of human error data based on a cognitive model: IDA

    International Nuclear Information System (INIS)

    This paper presents a model-based human error taxonomy and data collection. The underlying model, IDA (described in two companion papers), is a cognitive model of behavior developed for analysis of the actions of nuclear power plant operating crew during abnormal situations. The taxonomy is established with reference to three external reference points (i.e. plant status, procedures, and crew) and four reference points internal to the model (i.e. information collected, diagnosis, decision, action). The taxonomy helps the analyst: (1) recognize errors as such; (2) categorize the error in terms of generic characteristics such as 'error in selection of problem solving strategies' and (3) identify the root causes of the error. The data collection methodology is summarized in post event operator interview and analysis summary forms. The root cause analysis methodology is illustrated using a subset of an actual event. Statistics, which extract generic characteristics of error prone behaviors and error prone situations are presented. Finally, applications of the human error data collection are reviewed. A primary benefit of this methodology is to define better symptom-based and other auxiliary procedures with associated training to minimize or preclude certain human errors. It also helps in design of control rooms, and in assessment of human error probabilities in the probabilistic risk assessment framework. (orig.)

  18. Gold nanoparticles-based brachytherapy enhancement in choroidal melanoma using a full Monte Carlo modelling of human eye

    CERN Document Server

    Asadi, Somayeh; Masoudi, S Farhad; Rahmani, Faezeh

    2014-01-01

    Materials of high atomic number such as gold, can provide a high probability for photon interaction by photoelectric effects during radiation therapy. In cancer therapy, the object of brachytherapy as a kind of radiotherapy is to deliver adequate radiation dose to tumor while sparing surrounding healthy tissue. Several studies demonstrated that the preferential accumulation of gold nanoparticles within the tumor can enhance the absorbed dose by the tumor without increasing the radiation dose delivered externally. Accordingly, the required time for tumor irradiation decreases as the estimated adequate radiation dose for tumor is provided following this method. The dose delivered to healthy tissue is reduced when the time of irradiation is decreased. Hear, GNPs effects on choroidal Melanoma dosimetry is discussed by Monte Carlo study. Monte Carlo Ophthalmic brachytherapy dosimetry usually, is studied by simulation of water phantom. Considering the composition and density of eye material instead of water in thes...

  19. Automation of Commanding at NASA: Reducing Human Error in Space Flight

    Science.gov (United States)

    Dorn, Sarah J.

    2010-01-01

    Automation has been implemented in many different industries to improve efficiency and reduce human error. Reducing or eliminating the human interaction in tasks has been proven to increase productivity in manufacturing and lessen the risk of mistakes by humans in the airline industry. Human space flight requires the flight controllers to monitor multiple systems and react quickly when failures occur so NASA is interested in implementing techniques that can assist in these tasks. Using automation to control some of these responsibilities could reduce the number of errors the flight controllers encounter due to standard human error characteristics. This paper will investigate the possibility of reducing human error in the critical area of manned space flight at NASA.

  20. Role of data and judgment in modeling human errors

    International Nuclear Information System (INIS)

    Human beings are not a simple component. This is why prediction of human behaviour in a quantitative way is so difficult. For human reliability analysis, the data sources that can be used are the following: operating experience and incident reports, data banks, data from literature, data collected from simulators, data established by expert judgement. The factors important for conducting a good human reliability analysis are then discussed, including the uncertainties to be associated with. (orig.)

  1. Human Error in Medicine: Change in Cardiac Operating Rooms through the FOCUS Initiative

    OpenAIRE

    Spiess, Bruce D.

    2011-01-01

    Human error in medicine is a significant cause of patient mortality. While there has been increased attention to safety in medicine since the Institute of Medicine publication To Err is Human, the profession at large has not progressed to the same degree as other highly complex industries such as aviation and nuclear power. The Flawless Operative Cardiovascular Unified Systems initiative (FOCUS) is a multi-year study/intervention to learn about and to improve human error in cardiac surgery. F...

  2. New method of classifying human errors at nuclear power plants and the analysis results of applying this method to maintenance errors at domestic plants

    International Nuclear Information System (INIS)

    Since many of the adverse events that have occurred in nuclear power plants in Japan and abroad have been related to maintenance or operation, it is necessary to plan preventive measures based on detailed analyses of human errors made by maintenance workers or operators. Therefore, before planning preventive measures, we developed a new method of analyzing human errors. Since each human error is an unsafe action caused by some misjudgement made by a person, we decided to classify them into six categories according to the stage in the judgment process in which the error was made. By further classifying each error into either an omission-type or commission-type, we produced 12 categories of errors. Then, we divided them into the two categories of basic error tendencies and individual error tendencies, and categorized background factors into four categories: imperfect planning; imperfect facilities or tools; imperfect environment; and imperfect instructions or communication. We thus defined the factors in each category to make it easy to identify factors that caused the error. Then using this method, we studied the characteristics of human errors that involved maintenance workers and planners since many maintenance errors have occurred. Among the human errors made by workers (worker errors) during the implementation stage, the following three types were prevalent with approximately 80%: commission-type 'projection errors', omission-type comprehension errors' and commission type 'action errors'. The most common among the individual factors of worker errors was 'repetition or habit' (schema), based on the assumption of a typical situation, and the half number of the 'repetition or habit' cases (schema) were not influenced by any background factors. The most common background factor that contributed to the individual factor was 'imperfect work environment', followed by 'insufficient knowledge'. Approximately 80% of the individual factors were 'repetition or habit' or

  3. Prostate cancer brachytherapy

    International Nuclear Information System (INIS)

    The transperineal brachytherapy with 125I/Pd103 seed implantation guided by transurethral ultrasound must be presented as therapeutical option of low urinary morbidity in patients with localized prostate cancer. The combined clinical staging - including Gleason and initial PSA - must be encouraged, for definition of a group of low risk and indication of exclusive brachytherapy. Random prospective studies are necessary in order to define the best role of brachytherapy, surgery and external beam radiation therapy

  4. Classification and Analysis of Human Errors Involved in Test and Maintenance-Related Unplanned Reactor Trip Events

    International Nuclear Information System (INIS)

    Test and maintenance (T and M) human errors involved in unplanned reactor trip events in Korean nuclear power plants were analyzed according to James Reason's basic error types, and the characteristics of the T and M human errors by error type were delineated by the distinctive nature of major contributing factors, error modes, and the predictivity of possible errors. Human errors due to a planning failure where a work procedure is provided are dominated by the activities during low-power states or startup operations, and human errors due to a planning failure where a work procedure does not exist are dominated by corrective maintenance activities during full-power states. Human errors during execution of a planned work sequence show conspicuous error patterns; four error modes such as 'wrong object', 'omission', 'too little', and 'wrong action' appeared to be dominant. In view of a human error predictivity, human errors due to a planning failure is deemed to be very difficult to identify in advance, while human errors during execution are sufficiently predictable by using human error prediction or human reliability analysis methods with adequate resources

  5. Human Error and the International Space Station: Challenges and Triumphs in Science Operations

    Science.gov (United States)

    Harris, Samantha S.; Simpson, Beau C.

    2016-01-01

    Any system with a human component is inherently risky. Studies in human factors and psychology have repeatedly shown that human operators will inevitably make errors, regardless of how well they are trained. Onboard the International Space Station (ISS) where crew time is arguably the most valuable resource, errors by the crew or ground operators can be costly to critical science objectives. Operations experts at the ISS Payload Operations Integration Center (POIC), located at NASA's Marshall Space Flight Center in Huntsville, Alabama, have learned that from payload concept development through execution, there are countless opportunities to introduce errors that can potentially result in costly losses of crew time and science. To effectively address this challenge, we must approach the design, testing, and operation processes with two specific goals in mind. First, a systematic approach to error and human centered design methodology should be implemented to minimize opportunities for user error. Second, we must assume that human errors will be made and enable rapid identification and recoverability when they occur. While a systematic approach and human centered development process can go a long way toward eliminating error, the complete exclusion of operator error is not a reasonable expectation. The ISS environment in particular poses challenging conditions, especially for flight controllers and astronauts. Operating a scientific laboratory 250 miles above the Earth is a complicated and dangerous task with high stakes and a steep learning curve. While human error is a reality that may never be fully eliminated, smart implementation of carefully chosen tools and techniques can go a long way toward minimizing risk and increasing the efficiency of NASA's space science operations.

  6. Defining the Relationship Between Human Error Classes and Technology Intervention Strategies

    Science.gov (United States)

    Wiegmann, Douglas A.; Rantanen, Eas M.

    2003-01-01

    The modus operandi in addressing human error in aviation systems is predominantly that of technological interventions or fixes. Such interventions exhibit considerable variability both in terms of sophistication and application. Some technological interventions address human error directly while others do so only indirectly. Some attempt to eliminate the occurrence of errors altogether whereas others look to reduce the negative consequences of these errors. In any case, technological interventions add to the complexity of the systems and may interact with other system components in unforeseeable ways and often create opportunities for novel human errors. Consequently, there is a need to develop standards for evaluating the potential safety benefit of each of these intervention products so that resources can be effectively invested to produce the biggest benefit to flight safety as well as to mitigate any adverse ramifications. The purpose of this project was to help define the relationship between human error and technological interventions, with the ultimate goal of developing a set of standards for evaluating or measuring the potential benefits of new human error fixes.

  7. Towards an ecological approach to understanding the neurophysiological bases of human error-monitoring

    OpenAIRE

    Padrão, Gonçalo

    2014-01-01

    To err is certainly human. Detect and correct our errors are fundamental during our interaction with the outside world. Therefore, understanding the nature of the brain mechanisms involved in the flexible evaluation of human action and the adaptive changes that follow behavioral imperceptions is a basic goal of modern cognitive neuroscience. The study of the brain mechanisms of error-monitoring has advanced enormously during the last two decades, mostly due to the discovery of specifi...

  8. Human errors in test and maintenance of nuclear power plants. Nordic project work

    International Nuclear Information System (INIS)

    The present report is a summary of the NKA/LIT-1 project performed for the period 1981-1985. The report summarizes work on human error influence in test and calibration activities in nuclear power plants, reviews problems regarding optimization of the test intervals, organization of test and maintenance activities, and the analysis of human error contribution to the overall risk in test and mainenace tasks. (author)

  9. Resilience to evolving drinking water contamination risks: a human error prevention perspective

    OpenAIRE

    Tang, Yanhong; Wu, Shaomin; Miao, Xin; Pollard, Simon J. T.; Hrudey, Steve E

    2013-01-01

    Human error contributes to one of the major causes of the prevalence of drinking water contamination incidents. It has, however, attracted insufficient attention in the cleaner production management community. This paper analyzes human error appearing in each stage of the gestation of 40 drinking water incidents and their causes, proposes resilience-based mechanisms and tools within three groups: consumers, drinking water companies, and policy regulators. The mechanism analysis involves conce...

  10. SCHEME (Soft Control Human error Evaluation MEthod) for advanced MCR HRA

    International Nuclear Information System (INIS)

    The Technique for Human Error Rate Prediction (THERP), Korean Human Reliability Analysis (K-HRA), Human Error Assessment and Reduction Technique (HEART), A Technique for Human Event Analysis (ATHEANA), Cognitive Reliability and Error Analysis Method (CREAM), and Simplified Plant Analysis Risk Human Reliability Assessment (SPAR-H) in relation to NPP maintenance and operation. Most of these methods were developed considering the conventional type of Main Control Rooms (MCRs). They are still used for HRA in advanced MCRs even though the operating environment of advanced MCRs in NPPs has been considerably changed by the adoption of new human-system interfaces such as computer-based soft controls. Among the many features in advanced MCRs, soft controls are an important feature because the operation action in NPP advanced MCRs is performed by soft controls. Consequently, those conventional methods may not sufficiently consider the features of soft control execution human errors. To this end, a new framework of a HRA method for evaluating soft control execution human error is suggested by performing the soft control task analysis and the literature reviews regarding widely accepted human error taxonomies. In this study, the framework of a HRA method for evaluating soft control execution human error in advanced MCRs is developed. First, the factors which HRA method in advanced MCRs should encompass are derived based on the literature review, and soft control task analysis. Based on the derived factors, execution HRA framework in advanced MCRs is developed mainly focusing on the features of soft control. Moreover, since most current HRA database deal with operation in conventional type of MCRs and are not explicitly designed to deal with digital HSI, HRA database are developed under lab scale simulation

  11. SCHEME (Soft Control Human error Evaluation MEthod) for advanced MCR HRA

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Inseok; Jung, Wondea [KAERI, Daejeon (Korea, Republic of); Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    The Technique for Human Error Rate Prediction (THERP), Korean Human Reliability Analysis (K-HRA), Human Error Assessment and Reduction Technique (HEART), A Technique for Human Event Analysis (ATHEANA), Cognitive Reliability and Error Analysis Method (CREAM), and Simplified Plant Analysis Risk Human Reliability Assessment (SPAR-H) in relation to NPP maintenance and operation. Most of these methods were developed considering the conventional type of Main Control Rooms (MCRs). They are still used for HRA in advanced MCRs even though the operating environment of advanced MCRs in NPPs has been considerably changed by the adoption of new human-system interfaces such as computer-based soft controls. Among the many features in advanced MCRs, soft controls are an important feature because the operation action in NPP advanced MCRs is performed by soft controls. Consequently, those conventional methods may not sufficiently consider the features of soft control execution human errors. To this end, a new framework of a HRA method for evaluating soft control execution human error is suggested by performing the soft control task analysis and the literature reviews regarding widely accepted human error taxonomies. In this study, the framework of a HRA method for evaluating soft control execution human error in advanced MCRs is developed. First, the factors which HRA method in advanced MCRs should encompass are derived based on the literature review, and soft control task analysis. Based on the derived factors, execution HRA framework in advanced MCRs is developed mainly focusing on the features of soft control. Moreover, since most current HRA database deal with operation in conventional type of MCRs and are not explicitly designed to deal with digital HSI, HRA database are developed under lab scale simulation.

  12. A Human Reliability Analysis of Post- Accident Human Errors in the Low Power and Shutdown PSA of KSNP

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Daeil; Kim, J. H.; Jang, S. C

    2007-03-15

    Korea Atomic Energy Research Institute, using the ANS low power and shutdown (LPSD) probabilistic risk assessment (PRA) Standard, evaluated the LPSD PSA model of the KSNP, Yonggwang Units 5 and 6, and identified the items to be improved. The evaluation results of human reliability analysis (HRA) of the post-accident human errors in the LPSD PSA model for the KSNP showed that 10 items among 19 items of supporting requirements for those in the ANS PRA Standard were identified as them to be improved. Thus, we newly carried out a HRA for post-accident human errors in the LPSD PSA model for the KSNP. Following tasks are the improvements in the HRA of post-accident human errors of the LPSD PSA model for the KSNP compared with the previous one: Interviews with operators in the interpretation of the procedure, modeling of operator actions, and the quantification results of human errors, site visit. Applications of limiting value to the combined post-accident human errors. Documentation of information of all the input and bases for the detailed quantifications and the dependency analysis using the quantification sheets The assessment results for the new HRA results of post-accident human errors using the ANS LPSD PRA Standard show that above 80% items of its supporting requirements for post-accident human errors were graded as its Category II. The number of the re-estimated human errors using the LPSD Korea Standard HRA method is 385. Among them, the number of individual post-accident human errors is 253. The number of dependent post-accident human errors is 135. The quantification results of the LPSD PSA model for the KSNP with new HEPs show that core damage frequency (CDF) is increased by 5.1% compared with the previous baseline CDF It is expected that this study results will be greatly helpful to improve the PSA quality for the domestic nuclear power plants because they have sufficient PSA quality to meet the Category II of Supporting Requirements for the post

  13. Identification and quantifications of pre-accident human errors in the PSA of KSNP

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dae Il; Jung, W. D.; Yang, J. E

    2005-03-01

    Korea Atomic Energy Research Institute, using the ASME PRA Standard, evaluated the PSA model of the KSNP and identified the items to be improved to enhance its quality. The evaluation results of Human Reliability Analysis (HRA) of the pre-accident human errors in the PSA model of the KSNP showed that 10 items among 15 items of supporting requirements for those in the ASME PRA Standard were identified as them to be improved. Thus, we newly carried out a HRA for pre-accident human errors for the KSNP PSA model as the target of grading its quality above ASME PRA Standard Category I+. We considered potential pre-accident human errors for all manual valves and control/instrumentation equipments of the systems modeled in the KSNP PSA model except reactor protection system/ engineering safety features actuation system (RPS/ESFAS). After reviewing 160 manual valves and 56 control/instrumentation equipments, we identified 64 pre-accident human errors related to the test and maintenance tasks and identified 33 independent and 12 common pre-accident human errors related to the calibration tasks, and modeled them into the related systems. We documented information of all the input and bases for the qualitative screening analysis and the detailed quantification for all the potential pre-accident human errors. It was identified that the dominant contributors of the new pre-accident human errors to the CDF of the KSNP PSA model was those for the calibration tasks. The self-assessment results for the new HRA results using the ASME PRA Standard show that almost items of its supporting requirements for pre-accident human errors were graded above its Category I+. It is expected that the HRA results presented in this study will be greatly helpful to improve the PSA quality for the domestic nuclear power plants because they have sufficient PSA quality to meet the Category II of supporting requirements for the pre-accident human errors in the ASME PRA Standard. In the future, it is

  14. Predicting errors from reconfiguration patterns in human brain networks

    OpenAIRE

    Ekman, Matthias; Derrfuss, Jan; Tittgemeyer, Marc; Fiebach, Christian J.

    2012-01-01

    Task preparation is a complex cognitive process that implements anticipatory adjustments to facilitate future task performance. Little is known about quantitative network parameters governing this process in humans. Using functional magnetic resonance imaging (fMRI) and functional connectivity measurements, we show that the large-scale topology of the brain network involved in task preparation shows a pattern of dynamic reconfigurations that guides optimal behavior. This network could be deco...

  15. An experimental approach to validating a theory of human error in complex systems

    Science.gov (United States)

    Morris, N. M.; Rouse, W. B.

    1985-01-01

    The problem of 'human error' is pervasive in engineering systems in which the human is involved. In contrast to the common engineering approach of dealing with error probabilistically, the present research seeks to alleviate problems associated with error by gaining a greater understanding of causes and contributing factors from a human information processing perspective. The general approach involves identifying conditions which are hypothesized to contribute to errors, and experimentally creating the conditions in order to verify the hypotheses. The conceptual framework which serves as the basis for this research is discussed briefly, followed by a description of upcoming research. Finally, the potential relevance of this research to design, training, and aiding issues is discussed.

  16. A Method and Support Tool for the Analysis of Human Error Hazards in Digital Devices

    International Nuclear Information System (INIS)

    In recent years, many nuclear power plants have adopted modern digital I and C technologies since they are expected to significantly improve their performance and safety. Modern digital technologies were expected to significantly improve both the economical efficiency and safety of nuclear power plants. However, the introduction of an advanced main control room (MCR) is accompanied with lots of changes in forms and features and differences through virtue of new digital devices. Many user-friendly displays and new features in digital devices are not enough to prevent human errors in nuclear power plants (NPPs). It may be an urgent to matter find the human errors potentials due to digital devices, and their detailed mechanisms. We can then consider them during the design of digital devices and their interfaces. The characteristics of digital technologies and devices may give many opportunities to the interface management, and can be integrated into a compact single workstation in an advanced MCR, such that workers can operate the plant with minimum burden under any operating condition. However, these devices may introduce new types of human errors, and thus we need a means to evaluate and prevent such errors, especially within digital devices for NPPs. This research suggests a new method named HEA-BIS (Human Error Analysis based on Interaction Segment) to confirm and detect human errors associated with digital devices. This method can be facilitated by support tools when used to ensure the safety when applying digital devices in NPPs

  17. A Human Error Analysis with Physiological Signals during Utilizing Digital Devices

    International Nuclear Information System (INIS)

    The introduction of advanced MCR is accompanied with lots of changes and different forms and features through the virtue of new digital technologies. There are various kinds of digital devices such as flat panel displays, touch screens, and so on. The characteristics of these digital devices give many chances to the interface management, and can be integrated into a compact single workstation in an advanced MCR so that workers can operate the plant with minimum burden during any operating condition. However, these devices may introduce new types of human errors, and thus we need a means to evaluate and prevent such error, especially those related to the digital devices. Human errors have been retrospectively assessed for accident reviews and quantitatively evaluated through HRA for PSA. However, the ergonomic verification and validation is an important process to defend all human error potential in the NPP design. HRA is a crucial part of a PSA, and helps in preparing a countermeasure for design by drawing potential human error items that affect the overall safety of NPPs. Various HRA techniques are available however: they reveal shortages of the HMI design in the digital era. - HRA techniques depend on PSFs: this means that the scope dealing with human factors is previously limited, and thus all attributes of new digital devices may not be considered in HRA. - The data used to HRA are not close to the evaluation items. So, human error analysis is not easy to apply to design by several individual experiments and cases. - The results of HRA are not statistically meaningful because accidents including human errors in NPPs are rare and have been estimated as having an extremely low probability

  18. Errors in Seismic Hazard Assessment are Creating Huge Human Losses

    Science.gov (United States)

    Bela, J.

    2015-12-01

    The current practice of representing earthquake hazards to the public based upon their perceived likelihood or probability of occurrence is proven now by the global record of actual earthquakes to be not only erroneous and unreliable, but also too deadly! Earthquake occurrence is sporadic and therefore assumptions of earthquake frequency and return-period are both not only misleading, but also categorically false. More than 700,000 people have now lost their lives (2000-2011), wherein 11 of the World's Deadliest Earthquakes have occurred in locations where probability-based seismic hazard assessments had predicted only low seismic low hazard. Unless seismic hazard assessment and the setting of minimum earthquake design safety standards for buildings and bridges are based on a more realistic deterministic recognition of "what can happen" rather than on what mathematical models suggest is "most likely to happen" such future huge human losses can only be expected to continue! The actual earthquake events that did occur were at or near the maximum potential-size event that either already had occurred in the past; or were geologically known to be possible. Haiti's M7 earthquake, 2010 (with > 222,000 fatalities) meant the dead could not even be buried with dignity. Japan's catastrophic Tohoku earthquake, 2011; a M9 Megathrust earthquake, unleashed a tsunami that not only obliterated coastal communities along the northern Japanese coast, but also claimed > 20,000 lives. This tsunami flooded nuclear reactors at Fukushima, causing 4 explosions and 3 reactors to melt down. But while this history of huge human losses due to erroneous and misleading seismic hazard estimates, despite its wrenching pain, cannot be unlived; if faced with courage and a more realistic deterministic estimate of "what is possible", it need not be lived again. An objective testing of the results of global probability based seismic hazard maps against real occurrences has never been done by the

  19. An Empirical Study on Human Performance according to the Physical Environment (Potential Human Error Hazard) in Nuclear Power Plants

    International Nuclear Information System (INIS)

    The management of the physical environment for safety is more effective than a nuclear industry. Despite the physical environment such as lighting, noise satisfy with management standards, it can be background factors may cause human error and affect human performance. Because the consequence of extremely human error and human performance is high according to the physical environment, requirement standard could be covered with specific criteria. Particularly, in order to avoid human errors caused by an extremely low or rapidly-changing intensity illumination and masking effect such as power disconnection, plans for better visual environment and better function performances should be made as a careful study on efficient ways to manage and continue the better conditions is conducted

  20. An integrated systemic model for optimization of condition-based maintenance with human error

    International Nuclear Information System (INIS)

    This paper proposes an integrated systemic model for the integration of human reliability model with condition based maintenance (CBM) optimization. The problem of CBM optimization is formulated as finding the optimum parameters of a function for condition monitoring (CM) scheduling so that the average unit cost (AUC) of CBM system is minimized. The concept of functional resonance is employed to analyze human-induced failure scenarios emergent from erroneous functional dependencies. To quantify human reliability in CBM, the functional characteristics of human error in CBM as well as the main performance influencing factors (PIFs) are identified. The algorithms of diagnostics and prognostics are integrated in the simulation model of CBM. Then an exact simulation-optimization algorithm based on the use of two joint Fibonacci algorithms is proposed for global optimization of CM scheduling with human error. A sensitivity analysis has been performed based on the newly developed model considering multiple levels of human errors in CBM functions to observe the effects of human errors on overall system cost. The model is also useful in demonstrating the importance and effects of improving human and organizational aspects as well as technical aspects such as the accuracy and relevance of CM technology and the accuracy of prognostics algorithm

  1. Psychological scaling of expert estimates of human error probabilities: application to nuclear power plant operation

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission and Sandia National Laboratories sponsored a project to evaluate psychological scaling techniques for use in generating estimates of human error probabilities. The project evaluated two techniques: direct numerical estimation and paired comparisons. Expert estimates were found to be consistent across and within judges. Convergent validity was good, in comparison to estimates in a handbook of human reliability. Predictive validity could not be established because of the lack of actual relative frequencies of error (which will be a difficulty inherent in validation of any procedure used to estimate HEPs). Application of expert estimates in probabilistic risk assessment and in human factors is discussed

  2. HUMAN ERROR QUANTIFICATION USING PERFORMANCE SHAPING FACTORS IN THE SPAR-H METHOD

    Energy Technology Data Exchange (ETDEWEB)

    Harold S. Blackman; David I. Gertman; Ronald L. Boring

    2008-09-01

    This paper describes a cognitively based human reliability analysis (HRA) quantification technique for estimating the human error probabilities (HEPs) associated with operator and crew actions at nuclear power plants. The method described here, Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR-H) method, was developed to aid in characterizing and quantifying human performance at nuclear power plants. The intent was to develop a defensible method that would consider all factors that may influence performance. In the SPAR-H approach, calculation of HEP rates is especially straightforward, starting with pre-defined nominal error rates for cognitive vs. action-oriented tasks, and incorporating performance shaping factor multipliers upon those nominal error rates.

  3. A Study on EEG Analysis in Human Error Potential while using digital device in NPPs

    International Nuclear Information System (INIS)

    Human error potential (HEP) means a possibility of task performance failure based on the final consequence. The HEP of a digital device in nuclear power plants (NPPs) may be caused by perceptual deficiencies of human information processing and miss some operation of the digital device, and so on. There have been many studies to investigate HEP and how to prevent the human error but these mostly focused on probability. We apply a qualitative experimental study on HEP. The purpose of this study is to analyze EEG in HEP during the operation of a digital device in NPPs. We investigate the physiological signal, and evaluate the patterns and specific characteristics of the frequency during the task performance. Within the task process from perception the information to response execution while using a digital device in NPPs, EEG signal shows different pattern. These findings can be utilized to discriminate the HEP in the design of device in NPPs for human errors prevention

  4. Thresholds for human detection of patient setup errors in digitally reconstructed portal images of prostate fields

    International Nuclear Information System (INIS)

    Purpose: Computer-assisted methods to analyze electronic portal images for the presence of treatment setup errors should be studied in controlled experiments before use in the clinical setting. Validation experiments using images that contain known errors usually report the smallest errors that can be detected by the image analysis algorithm. This paper offers human error-detection thresholds as one benchmark for evaluating the smallest errors detected by algorithms. Unfortunately, reliable data are lacking describing human performance. The most rigorous benchmarks for human performance are obtained under conditions that favor error detection. To establish such benchmarks, controlled observer studies were carried out to determine the thresholds of detectability for in-plane and out-of-plane translation and rotation setup errors introduced into digitally reconstructed portal radiographs (DRPRs) of prostate fields. Methods and Materials: Seventeen observers comprising radiation oncologists, radiation oncology residents, physicists, and therapy students participated in a two-alternative forced choice experiment involving 378 DRPRs computed using the National Library of Medicine Visible Human data sets. An observer viewed three images at a time displayed on adjacent computer monitors. Each image triplet included a reference digitally reconstructed radiograph displayed on the central monitor and two DRPRs displayed on the flanking monitors. One DRPR was error free. The other DRPR contained a known in-plane or out-of-plane error in the placement of the treatment field over a target region in the pelvis. The range for each type of error was determined from pilot observer studies based on a Probit model for error detection. The smallest errors approached the limit of human visual capability. The observer was told what kind of error was introduced, and was asked to choose the DRPR that contained the error. Observer decisions were recorded and analyzed using repeated

  5. An assessment of the risk significance of human errors in selected PSAs and operating events

    International Nuclear Information System (INIS)

    Sensitivity studies based on Probabilistic Safety Assessments (PSAs) for a pressurized water reactor and a boiling water reactor are described. In each case human errors modeled in the PSAs were categorized according to such factors as error type, location, timing, and plant personnel involved. Sensitivity studies were then conducted by varying the error rates in each category and evaluating the corresponding change in total core damage frequency and accident sequence frequency. Insights obtained are discussed and reasons for differences in risk sensitivity between plants are explored. A separate investigation into the role of human error in risk-important operating events is also described. This investigation involved the analysis of data from the USNRC Accident Sequence Precursor program to determine the effect of operator-initiated events on accident precursor trends, and to determine whether improved training can be correlated to current trends. The findings of this study are also presented. 5 refs., 15 figs., 1 tab

  6. The Relationship between Human Operators' Psycho-physiological Condition and Human Errors in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Arryum; Jang, Inseok; Kang, Hyungook; Seong, Poonghyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-05-15

    The safe operation of nuclear power plants (NPPs) is substantially dependent on the performance of the human operators who operate the systems. In this environment, human errors caused by inappropriate performance of operator have been considered to be critical since it may lead serious problems in the safety-critical plants. In order to provide meaningful insights to prevent human errors and enhance the human performance, operators' physiological conditions such as stress and workload have been investigated. Physiological measurements were considered as reliable tools to assess the stress and workload. T. Q. Tran et al. and J. B. Brooking et al pointed out that operators' workload can be assessed using eye tracking, galvanic skin response, electroencephalograms (EEGs), heart rate, respiration and other measurements. The purpose of this study is to investigate the effect of the human operators' tense level and knowledge level to the number of human errors. For this study, the experiments were conducted in the mimic of the main control rooms (MCR) in NPP. It utilized the compact nuclear simulator (CNS) which is modeled based on the three loop Pressurized Water Reactor, 993MWe, Kori unit 3 and 4 in Korea and the subjects were asked to follow the tasks described in the emergency operating procedures (EOP). During the simulation, three kinds of physiological measurement were utilized; Electrocardiogram (ECG), EEG and nose temperature. Also, subjects were divided into three groups based on their knowledge of the plant operation. The result shows that subjects who are tense make fewer errors. In addition, subjects who are in higher knowledge level tend to be tense and make fewer errors. For the ECG data, subjects who make fewer human errors tend to be located in higher tense level area of high SNS activity and low PSNS activity. The results of EEG data are also similar to ECG result. Beta power ratio of subjects who make fewer errors was higher. Since beta

  7. Safety coaches in radiology: decreasing human error and minimizing patient harm

    International Nuclear Information System (INIS)

    Successful programs to improve patient safety require a component aimed at improving safety culture and environment, resulting in a reduced number of human errors that could lead to patient harm. Safety coaching provides peer accountability. It involves observing for safety behaviors and use of error prevention techniques and provides immediate feedback. For more than a decade, behavior-based safety coaching has been a successful strategy for reducing error within the context of occupational safety in industry. We describe the use of safety coaches in radiology. Safety coaches are an important component of our comprehensive patient safety program. (orig.)

  8. A Human Reliability Analysis of Pre-Accident Human Errors in the Low Power and Shutdown PSA of the KSNP

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Daeil; Jang, Seungchul

    2007-03-15

    Korea Atomic Energy Research Institute, using the ANS Low Power /Shutdown (LPSD)PRA Standard, evaluated the LPSD PSA model of the KSNP, Younggwang (YGN) Units 5 and 6, and identified the items to be improved. The evaluation results of human reliability analysis (HRA) of the pre-accident human errors in the LPSD PSA model of the KSNP showed that 13 items among 15 items of supporting requirements for those in the ANS PRA Standard were identified as them to be improved. Thus, we newly carried out a HRA for pre-accident human errors in the LPSD PSA model for the KSNP to improve its quality. We considered potential pre-accident human errors for all manual valves and control/instrumentation equipment of the systems modeled in the KSNP LPSD PSA model except reactor protection system/ engineering safety features actuation system. We reviewed 160 manual valves and 56 control/instrumentation equipment. The number of newly identified pre-accident human errors is 101. Among them, the number of those related to testing/maintenance tasks is 56. The number of those related to calibration tasks is 45. The number of those related to only shutdown operation is 10. It was shown that the pre-accident human errors related to only shutdown operation contributions to the core damage frequency of LPSD PSA model for the KSNP was negligible.The self-assessment results for the new HRA results of pre-accident human errors using the ANS LPSD PRA Standard show that above 80% items of its supporting requirements for post-accident human errors were graded as its Category II or III. It is expected that the HRA results for the pre-accident human errors presented in this study will be greatly helpful to improve the PSA quality for the domestic nuclear power plants because they have sufficient PSA quality to meet the Category II of supporting requirements for the postaccident human errors in the ANS LPSD PRA Standard.

  9. A study on simulation based evaluation of human error in operation and maintenance for nuclear power plants. System for human error analysis and evaluation

    International Nuclear Information System (INIS)

    Now large-scale systems such as nuclear power plants have been complicated. Therefore, it becomes increasingly necessary to analyze and evaluate the HMI (Human Machine Interface) for the reliability from the HF (Human Factor) standpoint. Meanwhile, it is also important to estimate the risk of HE (Human Error) in which task in an individual work process is based on the work manual. In this paper, we introduce three kinds of system that can be easily a quantitative analysis and evaluation concerning HE and/or HF. We adopt quantitative analysis method for HRA (Human Reliability Analysis), that is THERP (Technique for HE Rate Prediction) and Event Tree Analysis in the system. Using these systems, a person, who does not have enough knowledge of HF, can estimate a HF prevention method and a HMI remediation design, etc. in a series of work task. (author)

  10. Human factors--recognising and minimising errors in our day to day practice.

    Science.gov (United States)

    Green, B; Tsiroyannis, C; Brennan, P A

    2016-01-01

    A significant cause of mistakes in healthcare and which are potentially harmful or fatal to patients can result from both individual clinicians and their employing organisations. The understanding and recognition of the role of human error within the healthcare setting is improving, but we still have much to learn when compared with other high-risk organisations such as aviation where such errors can be devastating at a much larger scale. The importance of both organisational issues and human factor issues at a more personal level including tiredness, the effect of emotions and the role of situational awareness, needs to be understood by all those involved in healthcare. Potential mistakes can be reduced with simple measures which need to be recognised by, emphasised and embedded in both teams and individuals. In this review, we address the need for greater awareness of human factors, assessing the path to error and how this can be reduced to minimum levels in clinical practice. PMID:26500041

  11. The effectiveness of 125I seed interstitial brachytherapy for transplantation tumor of human pancreatic carcinoma in nude mice: an experiment in vivo

    International Nuclear Information System (INIS)

    Objective: To discuss the effectiveness and therapeutic mechanism of 125I interstitial brachytherapy for transplantation tumor of human pancreatic carcinoma in nude mice. Methods: The human pancreatic cell line Sw1990 was subcutaneously injected into the right lower limb partially dorsal area next to the groin of the immunodeficient BABL /c nude mice. The tumor was removed and cut into small pieces after it was formed,then the tumor pieces were inoculated in nude mice. The tumor developed to 8-10 mm in size after six weeks. A total of 16 nude mice with the suitable tumor size were used in this study. The 16 experimental mice were randomly and equally divided into two groups. The mice in study group (n = 8) were implanted with 125I seeds, while the mice in control group (n = 8) were implanted with ghost seeds. After the implantation both the long and short diameter of the tumors as well as the mouse body weight were measured every 4 days. The tumor weight was measured when the mouse was sacrificed. The paraffin-embedded samples were sent for histopathological examination. Apoptotic cells were checked with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. Expression of proliferating cell nuclear antigen (PCNA) was detected with immuno-histochemical staining. Results: The tumor grew slowly in the study group, but rapidly in the control group. The tumor weight in the study group and the control group was (2.68 ± 0.70)g and (4.68 ± 1.45)g, respectively, the difference between two groups was statistically significant (P = 0.021). The tumor inhibition rate was about 42.66%. No significant difference in body weight of nude mice existed between two groups both before and after the treatment (P > 0.05). Marked tumor necrosis was seen in study group, but no obvious, or only a little, tumor necrosis could be observed in the control group. The apoptotic index checked with the TUENL method in the study group and control group was (23.2 ± 1.9)% and

  12. A Conceptual Framework for Predicting Error in Complex Human-Machine Environments

    Science.gov (United States)

    Freed, Michael; Remington, Roger; Null, Cynthia H. (Technical Monitor)

    1998-01-01

    We present a Goals, Operators, Methods, and Selection Rules-Model Human Processor (GOMS-MHP) style model-based approach to the problem of predicting human habit capture errors. Habit captures occur when the model fails to allocate limited cognitive resources to retrieve task-relevant information from memory. Lacking the unretrieved information, decision mechanisms act in accordance with implicit default assumptions, resulting in error when relied upon assumptions prove incorrect. The model helps interface designers identify situations in which such failures are especially likely.

  13. Interstitial brachytherapy dosimetry update

    International Nuclear Information System (INIS)

    In March 2004, the American Association of Physicists in Medicine (AAPM) published an update to the AAPM Task Group No. 43 Report (TG-43) which was initially published in 1995. This update was pursued primarily due to the marked increase in permanent implantation of low-energy photon-emitting brachytherapy sources in the United States over the past decade, and clinical rationale for the need of accurate dosimetry in the implementation of interstitial brachytherapy. Additionally, there were substantial improvements in the brachytherapy dosimetry formalism, accuracy of related parameters and methods for determining these parameters. With salient background, these improvements are discussed in the context of radiation dosimetry. As an example, the impact of this update on the administered dose is assessed for the model 200 103Pd brachytherapy source. (authors)

  14. Human reliability analysis during PSA at Trillo NPP: main characteristics and analysis of diagnostic errors

    International Nuclear Information System (INIS)

    The design difference between Trillo NPP and other Spanish nuclear power plants (basic Westinghouse and General Electric designs) were made clear in the Human Reliability Analysis of the Probabilistic Safety Analysis (PSA) for Trillo NPP. The object of this paper is to describe the most significant characteristics of the Human Reliability Analysis carried out in the PSA, with special emphasis on the possible diagnostic errors and their consequences, based on the characteristics in the Emergency Operations Manual for Trillo NPP. - In the case of human errors before the initiating event (type 1), the existence of four redundancies in most of the plant safety systems, means that the impact of this type or error on the final results of the PSA is insignificant. However, in the case common cause errors, especially in certain calibration errors, some actions are significant in the final equation for core damage - The number of human actions that the operator has to carry out during the accidents (type 3) modelled, is relatively small in comparison with this value in other PSAs. This is basically due to the high level of automation at Rillo NPP - The Plant Operations Manual cannot be strictly considered to be a symptoms-based procedure. The operation Group must select the chapter from the Operations Manual to be followed, after having diagnosed the perturbing event, using for this purpose and Emergency and Anomaly Decision Tree (M.O.3.0.1) based on the different indications, alarms and symptoms present in the plant after the perturbing event. For this reason, it was decided to analyse the possible diagnosis errors. In the bibliography on diagnosis and commission errors available at the present time, there is no precise methodology for the analysis of this type of error and its incorporation into PSAs. The method used in the PSA for Trillo y NPP to evaluate this type of interaction, is to develop a Diagnosis Error Table, the object of which is to identify the situations in

  15. An advanced human reliability analysis methodology: analysis of cognitive errors focused on

    International Nuclear Information System (INIS)

    The conventional Human Reliability Analysis (HRA) methods such as THERP/ASEP, HCR and SLIM has been criticised for their deficiency in analysing cognitive errors which occurs during operator's decision making process. In order to supplement the limitation of the conventional methods, an advanced HRA method, what is called the 2nd generation HRA method, including both qualitative analysis and quantitative assessment of cognitive errors has been being developed based on the state-of-the-art theory of cognitive systems engineering and error psychology. The method was developed on the basis of human decision-making model and the relation between the cognitive function and the performance influencing factors. The application of the proposed method to two emergency operation tasks is presented

  16. Methodological Approach for Performing Human Reliability and Error Analysis in Railway Transportation System

    Directory of Open Access Journals (Sweden)

    Fabio De Felice

    2011-10-01

    Full Text Available Today, billions of dollars are being spent annually world wide to develop, manufacture, and operate transportation system such trains, ships, aircraft, and motor vehicles. Around 70 to 90 percent oftransportation crashes are, directly or indirectly, the result of human error. In fact, with the development of technology, system reliability has increased dramatically during the past decades, while human reliability has remained unchanged over the same period. Accordingly, human error is now considered as the most significant source of accidents or incidents in safety-critical systems. The aim of the paper is the proposal of a methodological approach to improve the transportation system reliability and in particular railway transportation system. The methodology presented is based on Failure Modes, Effects and Criticality Analysis (FMECA and Human Reliability Analysis (HRA.

  17. Deadline pressure and human error: a study of human failures on a particle accelerator at Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    The decline in industrial efficiency may be linked to decreased reliability of complex automatic systems. This decline threatens the viability of complex organizations in industrialized economies. Industrial engineering techniques that minimize system failure by increasing the reliability of systems hardware are well developed in comparison with those available to reduce human operator errors. The problem of system reliability and the associated costs of breakdown can be reduced if we understand how highly skilled technical personnel function in complex operations and systems. The purpose of this research is to investigate how human errors are affected by deadline pressures, technical communication and other socio-dynamic factors. Through the analysis of a technologically complex particle accelerator prototype at Brookhaven National Laboratory, two failure mechanisms: (1) physical defects in the production process and (2) human operator errors were identified. Two instruments were used to collect information on human failures: objective laboratory data and a human failure questionnaire. The results of human failures from the objective data were used to test for the deadline hypothesis and also to validate the human failure questionnaire. To explain why the human failures occurred, data were collected from a four-part, closed choice questionnaire administered to two groups of scientists, engineers, and technicians, working together against a deadline to produce an engineering prototype of a particle accelerator

  18. Collection and classification of human error and human reliability data from Indian nuclear power plants for use in PSA

    International Nuclear Information System (INIS)

    Complex systems such as NPPs involve a large number of Human Interactions (HIs) in every phase of plant operations. Human Reliability Analysis (HRA) in the context of a PSA, attempts to model the HIs and evaluate/predict their impact on safety and reliability using human error/human reliability data. A large number of HRA techniques have been developed for modelling and integrating HIs into PSA but there is a significant lack of HAR data. In the face of insufficient data, human reliability analysts have had to resort to expert judgement methods in order to extend the insufficient data sets. In this situation, the generation of data from plant operating experience assumes importance. The development of a HRA data bank for Indian nuclear power plants was therefore initiated as part of the programme of work on HRA. Later, with the establishment of the coordinated research programme (CRP) on collection of human reliability data and use in PSA by IAEA in 1994-95, the development was carried out under the aegis of the IAEA research contract No. 8239/RB. The work described in this report covers the activities of development of a data taxonomy and a human error reporting form (HERF) based on it, data structuring, review and analysis of plant event reports, collection of data on human errors, analysis of the data and calculation of human error probabilities (HEPs). Analysis of plant operating experience does yield a good amount of qualitative data but obtaining quantitative data on human reliability in the form of HEPs is seen to be more difficult. The difficulties have been highlighted and some ways to bring about improvements in the data situation have been discussed. The implementation of a data system for HRA is described and useful features that can be incorporated in future systems are also discussed. (author)

  19. Human error data collection as a precursor to the development of a human reliability assessment capability in air traffic management

    International Nuclear Information System (INIS)

    Quantified risk and safety assessments are now required for safety cases for European air traffic management (ATM) services. Since ATM is highly human-dependent for its safety, this suggests a need for formal human reliability assessment (HRA), as carried out in other industries such as nuclear power. Since the fundamental aspect of HRA is human error data, in the form of human error probabilities (HEPs), it was decided to take a first step towards development of an ATM HRA approach by deriving some HEPs in an ATM context. This paper reports a study, which collected HEPs via analysing the results of a real-time simulation involving air traffic controllers (ATCOs) and pilots, with a focus on communication errors. This study did indeed derive HEPs that were found to be concordant with other known communication human error data. This is a first step, and shows promise for HRA in ATM, since HEPs have been derived which could be used in safety assessments, although these HEPs are for only one (albeit critical) aspect of ATCOs' tasks (communications). The paper discusses options and potential ways forward for the development of a full HRA capability in ATM

  20. An empirical study on the human error recovery failure probability when using soft controls in NPP advanced MCRs

    International Nuclear Information System (INIS)

    Highlights: • Many researchers have tried to understand human recovery process or step. • Modeling human recovery process is not sufficient to be applied to HRA. • The operation environment of MCRs in NPPs has changed by adopting new HSIs. • Recovery failure probability in a soft control operation environment is investigated. • Recovery failure probability here would be important evidence for expert judgment. - Abstract: It is well known that probabilistic safety assessments (PSAs) today consider not just hardware failures and environmental events that can impact upon risk, but also human error contributions. Consequently, the focus on reliability and performance management has been on the prevention of human errors and failures rather than the recovery of human errors. However, the recovery of human errors is as important as the prevention of human errors and failures for the safe operation of nuclear power plants (NPPs). For this reason, many researchers have tried to find a human recovery process or step. However, modeling the human recovery process is not sufficient enough to be applied to human reliability analysis (HRA), which requires human error and recovery probabilities. In this study, therefore, human error recovery failure probabilities based on predefined human error modes were investigated by conducting experiments in the operation mockup of advanced/digital main control rooms (MCRs) in NPPs. To this end, 48 subjects majoring in nuclear engineering participated in the experiments. In the experiments, using the developed accident scenario based on tasks from the standard post trip action (SPTA), the steam generator tube rupture (SGTR), and predominant soft control tasks, which are derived from the loss of coolant accident (LOCA) and the excess steam demand event (ESDE), all error detection and recovery data based on human error modes were checked with the performance sheet and the statistical analysis of error recovery/detection was then

  1. Support of protective work of human error in a nuclear power plant

    International Nuclear Information System (INIS)

    The nuclear power plant human factor group of the Tokyo Electric Power Co., Ltd. supports various protective work of human error conducted at the nuclear power plant. Its main researching theme are studies on human factor on operation of a nuclear power plant, and on recovery and common basic study on human factor. In addition, on a base of the obtained informations, assistance to protective work of human error conducted at the nuclear power plant as well as development for its actual use was also promoted. Especially, for actions sharing some dangerous informations, various assistances such as a proposal on actual example analytical method to effectively understand a dangerous information not facially but faithfully, construction of a data base to conveniently share such dangerous information, and practice on non-accident business survey for a hint of effective promotion of the protection work, were promoted. Here were introduced on assistance and investigation for effective sharing of the dangerous informations for various actions on protection of human error mainly conducted in nuclear power plant. (G.K.)

  2. In-plant reliability data base for nuclear plant components: a feasibility study on human error information

    International Nuclear Information System (INIS)

    This report documents the procedure and final results of a feasibility study which examined the usefulness of nuclear plant maintenance work requests in the IPRDS as tools for understanding human error and its influence on component failure and repair. Developed in this study were (1) a set of criteria for judging the quality of a plant maintenance record set for studying human error; (2) a scheme for identifying human errors in the maintenance records; and (3) two taxonomies (engineering-based and psychology-based) for categorizing and coding human error-related events

  3. Systematic analysis of dependent human errors from the maintenance history at finnish NPPs - A status report

    International Nuclear Information System (INIS)

    Operating experience has shown missed detection events, where faults have passed inspections and functional tests to operating periods after the maintenance activities during the outage. The causes of these failures have often been complex event sequences, involving human and organisational factors. Especially common cause and other dependent failures of safety systems may significantly contribute to the reactor core damage risk. The topic has been addressed in the Finnish studies of human common cause failures, where experiences on latent human errors have been searched and analysed in detail from the maintenance history. The review of the bulk of the analysis results of the Olkiluoto and Loviisa plant sites shows that the instrumentation and control and electrical equipment is more prone to human error caused failure events than the other maintenance and that plant modifications and also predetermined preventive maintenance are significant sources of common cause failures. Most errors stem from the refuelling and maintenance outage period at the both sites, and less than half of the dependent errors were identified during the same outage. The dependent human errors originating from modifications could be reduced by a more tailored specification and coverage of their start-up testing programs. Improvements could also be achieved by a more case specific planning of the installation inspection and functional testing of complicated maintenance works or work objects of higher plant safety and availability importance. A better use and analysis of condition monitoring information for maintenance steering could also help. The feedback from discussions of the analysis results with plant experts and professionals is still crucial in developing the final conclusions and recommendations that meet the specific development needs at the plants. (au)

  4. A human error probability estimate methodology based on fuzzy inference and expert judgment on nuclear plants

    International Nuclear Information System (INIS)

    Recent studies point human error as an important factor for many industrial and nuclear accidents: Three Mile Island (1979), Bhopal (1984), Chernobyl and Challenger (1986) are classical examples. Human contribution to these accidents may be better understood and analyzed by using Human Reliability Analysis (HRA), which has being taken as an essential part on Probabilistic Safety Analysis (PSA) of nuclear plants. Both HRA and PSA depend on Human Error Probability (HEP) for a quantitative analysis. These probabilities are extremely affected by the Performance Shaping Factors (PSF), which has a direct effect on human behavior and thus shape HEP according with specific environment conditions and personal individual characteristics which are responsible for these actions. This PSF dependence raises a great problem on data availability as turn these scarcely existent database too much generic or too much specific. Besides this, most of nuclear plants do not keep historical records of human error occurrences. Therefore, in order to overcome this occasional data shortage, a methodology based on Fuzzy Inference and expert judgment was employed in this paper in order to determine human error occurrence probabilities and to evaluate PSF's on performed actions by operators in a nuclear power plant (IEA-R1 nuclear reactor). Obtained HEP values were compared with reference tabled data used on current literature in order to show method coherence and valid approach. This comparison leads to a conclusion that this work results are able to be employed both on HRA and PSA enabling efficient prospection of plant safety conditions, operational procedures and local working conditions potential improvements (author)

  5. Development of a framework to estimate human error for diagnosis tasks in advanced control room

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ar Ryum; Jang, In Seok; Seong, Proong Hyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-10-15

    In the emergency situation of nuclear power plants (NPPs), a diagnosis of the occurring events is crucial for managing or controlling the plant to a safe and stable condition. If the operators fail to diagnose the occurring events or relevant situations, their responses can eventually inappropriate or inadequate Accordingly, huge researches have been performed to identify the cause of diagnosis error and estimate the probability of diagnosis error. D.I Gertman et al. asserted that 'the cognitive failures stem from erroneous decision-making, poor understanding of rules and procedures, and inadequate problem solving and this failures may be due to quality of data and people's capacity for processing information'. Also many researchers have asserted that human-system interface (HSI), procedure, training and available time are critical factors to cause diagnosis error. In nuclear power plants, a diagnosis of the event is critical for safe condition of the system. As advanced main control room is being adopted in nuclear power plants, the operators may obtain the plant data via computer-based HSI and procedure. Also many researchers have asserted that HSI, procedure, training and available time are critical factors to cause diagnosis error. In this regards, using simulation data, diagnosis errors and its causes were identified. From this study, some useful insights to reduce diagnosis errors of operators in advanced main control room were provided.

  6. Human error recovery failure probability when using soft controls in computerized control rooms

    International Nuclear Information System (INIS)

    Many literatures categorized recovery process into three phases; detection of problem situation, explanation of problem causes or countermeasures against problem, and end of recovery. Although the focus of recovery promotion has been on categorizing recovery phases and modeling recovery process, research related to human recovery failure probabilities has not been perform actively. On the other hand, a few study regarding recovery failure probabilities were implemented empirically. Summarizing, researches that have performed so far have several problems in terms of use in human reliability analysis (HRA). By adopting new human-system interfaces that are based on computer-based technologies, the operation environment of MCRs in NPPs has changed from conventional MCRs to advanced MCRs. Because of the different interfaces between conventional and advanced MCRs, different recovery failure probabilities should be considered in the HRA for advanced MCRs. Therefore, this study carries out an empirical analysis of human error recovery probabilities under an advanced MCR mockup called compact nuclear simulator (CNS). The aim of this work is not only to compile a recovery failure probability database using the simulator for advanced MCRs but also to collect recovery failure probability according to defined human error modes to compare that which human error mode has highest recovery failure probability. The results show that recovery failure probability regarding wrong screen selection was lowest among human error modes, which means that most of human error related to wrong screen selection can be recovered. On the other hand, recovery failure probabilities of operation selection omission and delayed operation were 1.0. These results imply that once subject omitted one task in the procedure, they have difficulties finding and recovering their errors without supervisor's assistance. Also, wrong screen selection had an effect on delayed operation. That is, wrong screen

  7. A Benefit/Cost/Deficit (BCD) model for learning from human errors

    International Nuclear Information System (INIS)

    This paper proposes an original model for interpreting human errors, mainly violations, in terms of benefits, costs and potential deficits. This BCD model is then used as an input framework to learn from human errors, and two systems based on this model are developed: a case-based reasoning system and an artificial neural network system. These systems are used to predict a specific human car driving violation: not respecting the priority-to-the-right rule, which is a decision to remove a barrier. Both prediction systems learn from previous violation occurrences, using the BCD model and four criteria: safety, for identifying the deficit or the danger; and opportunity for action, driver comfort, and time spent; for identifying the benefits or the costs. The application of learning systems to predict car driving violations gives a rate over 80% of correct prediction after 10 iterations. These results are validated for the non-respect of priority-to-the-right rule.

  8. Development of an improved HRA method: A technique for human error analysis (ATHEANA)

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, J.H.; Luckas, W.J. [Brookhaven National Lab., Upton, NY (United States); Wreathall, J. [John Wreathall & Co., Dublin, OH (United States)] [and others

    1996-03-01

    Probabilistic risk assessment (PRA) has become an increasingly important tool in the nuclear power industry, both for the Nuclear Regulatory Commission (NRC) and the operating utilities. The NRC recently published a final policy statement, SECY-95-126, encouraging the use of PRA in regulatory activities. Human reliability analysis (HRA), while a critical element of PRA, has limitations in the analysis of human actions in PRAs that have long been recognized as a constraint when using PRA. In fact, better integration of HRA into the PRA process has long been a NRC issue. Of particular concern, has been the omission of errors of commission - those errors that are associated with inappropriate interventions by operators with operating systems. To address these concerns, the NRC identified the need to develop an improved HRA method, so that human reliability can be better represented and integrated into PRA modeling and quantification.

  9. Development of an improved HRA method: A technique for human error analysis (ATHEANA)

    International Nuclear Information System (INIS)

    Probabilistic risk assessment (PRA) has become an increasingly important tool in the nuclear power industry, both for the Nuclear Regulatory Commission (NRC) and the operating utilities. The NRC recently published a final policy statement, SECY-95-126, encouraging the use of PRA in regulatory activities. Human reliability analysis (HRA), while a critical element of PRA, has limitations in the analysis of human actions in PRAs that have long been recognized as a constraint when using PRA. In fact, better integration of HRA into the PRA process has long been a NRC issue. Of particular concern, has been the omission of errors of commission - those errors that are associated with inappropriate interventions by operators with operating systems. To address these concerns, the NRC identified the need to develop an improved HRA method, so that human reliability can be better represented and integrated into PRA modeling and quantification

  10. Trend analysis of human error events and assessment of their proactive prevention measure at Rokkasho reprocessing plant

    International Nuclear Information System (INIS)

    A trend analysis of human error events is important for preventing the recurrence of human error events. We propose a new method for identifying the common characteristics from results of trend analysis, such as the latent weakness of organization, and a management process for strategic error prevention. In this paper, we describe a trend analysis method for human error events that have been accumulated in the organization and the utilization of the results of trend analysis to prevent accidents proactively. Although the systematic analysis of human error events, the monitoring of their overall trend, and the utilization of the analyzed results have been examined for the plant operation, such information has never been utilized completely. Sharing information on human error events and analyzing their causes lead to the clarification of problems in the management and human factors. This new method was applied to the human error events that occurred in the Rokkasho reprocessing plant from 2010 October. Results revealed that the output of this method is effective in judging the error prevention plan and that the number of human error events is reduced to about 50% those observed in 2009 and 2010. (author)

  11. Independent brachytherapy plan verification software: Improving efficacy and efficiency

    International Nuclear Information System (INIS)

    Background and purpose: To compare the pre-treatment brachytherapy plan verification by a physicist assisted by custom plan verification software (SAV) with those performed manually (MV). Materials and methods: All HDR brachytherapy plans used for treatment in 2013, verified using either SAV or MV, were retrospectively reviewed. Error rate (number of errors/number of plans) was measured and verification time calculated. All HDR brachytherapy safety events recorded between 2010 and 2013 were identified. The rate of patient-related safety events (number of events/number of fractions treated) and the impact of SAV on the underlying errors were assessed. Results: Three/106 errors (2.8%) were found in the SAV group and 24/273 (8.8%) in the MV group (p = 0.046). The mean ±1 standard deviation plan verification time was 8.4 ± 4.0 min for SAV and 11.6 ± 5.3 for MV (p = 0.006). Seven safety events out of 4729 fractions delivered (0.15%) were identified. Four events (57%) were associated with plan verification and could have been detected by SAV. Conclusions: We found a safety event rate in HDR brachytherapy of 0.15%. SAV significantly reduced the number of undetected errors in HDR treatment plans compared to MV, and reduced the time required for plan verification

  12. Measuring The Influence of TAsk COMplexity on Human Error Probability: An Empirical Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Podofillini, Luca; Dang, Vinh N. [Paul Scherrer Institute, Villigen (Switzerland)

    2013-04-15

    A key input for the assessment of Human Error Probabilities (HEPs) with Human Reliability Analysis (HRA) methods is the evaluation of the factors influencing the human performance (often referred to as Performance Shaping Factors, PSFs). In general, the definition of these factors and the supporting guidance are such that their evaluation involves significant subjectivity. This affects the repeatability of HRA results as well as the collection of HRA data for model construction and verification. In this context, the present paper considers the TAsk COMplexity (TACOM) measure, developed by one of the authors to quantify the complexity of procedure-guided tasks (by the operating crew of nuclear power plants in emergency situations), and evaluates its use to represent (objectively and quantitatively) task complexity issues relevant to HRA methods. In particular, TACOM scores are calculated for five Human Failure Events (HFEs) for which empirical evidence on the HEPs (albeit with large uncertainty) and influencing factors are available from the International HRA Empirical Study. The empirical evaluation has shown promising results. The TACOM score increases as the empirical HEP of the selected HFEs increases. Except for one case, TACOM scores are well distinguished if related to different difficulty categories (e. g., 'easy' vs. 'somewhat difficult'), while values corresponding to tasks within the same category are very close. Despite some important limitations related to the small number of HFEs investigated and the large uncertainty in their HEPs, this paper presents one of few attempts to empirically study the effect of a performance shaping factor on the human error probability. This type of study is important to enhance the empirical basis of HRA methods, to make sure that 1) the definitions of the PSFs cover the influences important for HRA (i. e., influencing the error probability), and 2) the quantitative relationships among PSFs and error

  13. Measuring The Influence of TAsk COMplexity on Human Error Probability: An Empirical Evaluation

    International Nuclear Information System (INIS)

    A key input for the assessment of Human Error Probabilities (HEPs) with Human Reliability Analysis (HRA) methods is the evaluation of the factors influencing the human performance (often referred to as Performance Shaping Factors, PSFs). In general, the definition of these factors and the supporting guidance are such that their evaluation involves significant subjectivity. This affects the repeatability of HRA results as well as the collection of HRA data for model construction and verification. In this context, the present paper considers the TAsk COMplexity (TACOM) measure, developed by one of the authors to quantify the complexity of procedure-guided tasks (by the operating crew of nuclear power plants in emergency situations), and evaluates its use to represent (objectively and quantitatively) task complexity issues relevant to HRA methods. In particular, TACOM scores are calculated for five Human Failure Events (HFEs) for which empirical evidence on the HEPs (albeit with large uncertainty) and influencing factors are available from the International HRA Empirical Study. The empirical evaluation has shown promising results. The TACOM score increases as the empirical HEP of the selected HFEs increases. Except for one case, TACOM scores are well distinguished if related to different difficulty categories (e. g., 'easy' vs. 'somewhat difficult'), while values corresponding to tasks within the same category are very close. Despite some important limitations related to the small number of HFEs investigated and the large uncertainty in their HEPs, this paper presents one of few attempts to empirically study the effect of a performance shaping factor on the human error probability. This type of study is important to enhance the empirical basis of HRA methods, to make sure that 1) the definitions of the PSFs cover the influences important for HRA (i. e., influencing the error probability), and 2) the quantitative relationships among PSFs and error probability are

  14. A method to deal with installation errors of wearable accelerometers for human activity recognition

    International Nuclear Information System (INIS)

    Human activity recognition (HAR) by using wearable accelerometers has gained significant interest in recent years in a range of healthcare areas, including inferring metabolic energy expenditure, predicting falls, measuring gait parameters and monitoring daily activities. The implementation of HAR relies heavily on the correctness of sensor fixation. The installation errors of wearable accelerometers may dramatically decrease the accuracy of HAR. In this paper, a method is proposed to improve the robustness of HAR to the installation errors of accelerometers. The method first calculates a transformation matrix by using Gram–Schmidt orthonormalization in order to eliminate the sensor's orientation error and then employs a low-pass filter with a cut-off frequency of 10 Hz to eliminate the main effect of the sensor's misplacement. The experimental results showed that the proposed method obtained a satisfactory performance for HAR. The average accuracy rate from ten subjects was 95.1% when there were no installation errors, and was 91.9% when installation errors were involved in wearable accelerometers

  15. El error en la práctica médica: una presencia ineludible Human error in medical practice: an unavoidable presence

    Directory of Open Access Journals (Sweden)

    Gladis Adriana Vélez Álvarez

    2006-01-01

    Full Text Available El errar, que es una característica humana y un mecanismo de aprendizaje, se convierte en una amenaza para el hombre mismo en algunos escenarios como la aviación y la medicina. Se presentan algunos datos acerca de la frecuencia del error en medicina, su ubicuidad y las circunstancias que lo favorecen, y se hace una reflexión acerca de cómo se ha enfrentado el error y de por qué no se habla abiertamente del mismo. Se propone que el primer paso para aprender del error es aceptarlo como una presencia ineludible. Making mistakes is a human characteristic and a mechanism to learn, but at the same time it may become a threat to human beings in some scenarios. Aviation and Medicine are good examples of this. Some data are presented about the frequency of error in Medicine, its ubiquity and the circumstances that favor it. A reflection is done about how the error is being managed and why it is not more often discussed. It is proposed that the first step in learning from an error is to accept it as an unavoidable presence.

  16. Source position verification and dosimetry in HDR brachytherapy using an EPID

    International Nuclear Information System (INIS)

    Purpose: Accurate treatment delivery in high dose rate (HDR) brachytherapy requires correct source dwell positions and dwell times to be administered relative to each other and to the surrounding anatomy. Treatment delivery inaccuracies predominantly occur for two reasons: (i) anatomical movement or (ii) as a result of human errors that are usually related to incorrect implementation of the planned treatment. Electronic portal imaging devices (EPIDs) were originally developed for patient position verification in external beam radiotherapy and their application has been extended to provide dosimetric information. The authors have characterized the response of an EPID for use with an 192Ir brachytherapy source to demonstrate its use as a verification device, providing both source position and dosimetric information.Methods: Characterization of the EPID response using an 192Ir brachytherapy source included investigations of reproducibility, linearity with dose rate, photon energy dependence, and charge build-up effects associated with exposure time and image acquisition time. Source position resolution in three dimensions was determined. To illustrate treatment verification, a simple treatment plan was delivered to a phantom and the measured EPID dose distribution compared with the planned dose.Results: The mean absolute source position error in the plane parallel to the EPID, for dwells measured at 50, 100, and 150 mm source to detector distances (SDD), was determined to be 0.26 mm. The resolution of the z coordinate (perpendicular distance from detector plane) is SDD dependent with 95% confidence intervals of ±0.1, ±0.5, and ±2.0 mm at SDDs of 50, 100, and 150 mm, respectively. The response of the EPID is highly linear to dose rate. The EPID exhibits an over-response to low energy incident photons and this nonlinearity is incorporated into the dose calibration procedure. A distance (spectral) dependent dose rate calibration procedure has been developed. The

  17. Safety assessment by complex algorithm for human errors in nuclear power plants (NPPs) using physiological cycles

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hyo Sung [Yonsei Univ., Wonju (Korea, Republic of). Dept. of Radiological Science; Woo, Tae Ho [Systemix Global Co. Ltd., Seoul (Korea, Republic of)

    2015-07-15

    The human error is analyzed by using non-linear time flows in the case of nuclear power plants (NPPs) accidents. The decision making is performed using complex non-linear dynamical simulations. This gives multiple descriptions in any event of NPPs, which can give the better solution in the event response procedures. The time step incorporated with human error equations describes two different cases of the non-linear time flows. The parallel theory is utilized for time step changes, because time flows are different by the simulation calculation sequences variation. Comparisons bet-ween two cases can give the priority in the reliability of the event, where quantitative values show the dynamical performances in the designed event. Top events are quantified by the time step of 1.0 and 0.5. The values of time step 1.0 has higher than those of time step 0.5 in the study.

  18. Safety assessment by complex algorithm for human errors in nuclear power plants (NPPs) using physiological cycles

    International Nuclear Information System (INIS)

    The human error is analyzed by using non-linear time flows in the case of nuclear power plants (NPPs) accidents. The decision making is performed using complex non-linear dynamical simulations. This gives multiple descriptions in any event of NPPs, which can give the better solution in the event response procedures. The time step incorporated with human error equations describes two different cases of the non-linear time flows. The parallel theory is utilized for time step changes, because time flows are different by the simulation calculation sequences variation. Comparisons bet-ween two cases can give the priority in the reliability of the event, where quantitative values show the dynamical performances in the designed event. Top events are quantified by the time step of 1.0 and 0.5. The values of time step 1.0 has higher than those of time step 0.5 in the study.

  19. Human Error Probabilites (HEPs) for generic tasks and Performance Shaping Factors (PSFs) selected for railway operations

    DEFF Research Database (Denmark)

    Thommesen, Jacob; Andersen, Henning Boje

    This report describes an HRA (Human Reliability Assessment) of six generic tasks and four Perfor-mance Shaping Factors (PSFs) targeted at railway operations commissioned by Banedanmark. The selection and characterization of generic tasks and PSFs are elaborated by DTU Management in close...... task level, which can be performed with fewer resources than a more detailed analysis of specific errors for each task. The generic tasks are presented with estimated Human Error Probabili-ties (HEPs) based on and extrapolated from the HRA literature, and estimates are compared with samples of measures...... collaboration with Banedanmark. The estimates provided are based on HRA literature and primarily the HEART method, being recently been adapted for railway tasks by the British Rail Safety and Stan-dards Board (RSSB). The method presented in this report differs from the RSSB tool by supporting an analysis at...

  20. Pengaruh Seleksi, Penempatan, dan Pelatihan Terhadap Human Error Paramedis di RSIA. Stella Maris kota Medan

    OpenAIRE

    Evyta, Helny

    2016-01-01

    RSIA. Stella Maris is a special serving women and children’s health hospital. The healthy service in RSIA. Stella Maris is doing by team of doctors in obstetrics and gynecology, pediatrician, related specialist doctors, nurses, tecologist, and equipped by other professionals in non-medical line. This research aims to identify and to analyze the influence of selection, placement, and training of human error paramedic at RSIA. Stella Maris Medan city. The population of this research were all pa...

  1. Sample Size Bounding and Context Ranking as Approaches to the Human Error Quantification Problem

    International Nuclear Information System (INIS)

    The paper describes a technique denoted as Sub-Sample-Size Bounding (SSSB), which is useable for the statistical derivation of context-specific probabilities from data available in existing reports on operating experience. Applications to human reliability analysis (HRA) are emphasised in the presentation of this technique. Exemplified by a sample of 180 abnormal event sequences, the manner in which SSSB can provide viable input for the quantification of errors of commission (EOCs) are outlined. (author)

  2. Anticipating human error before it happens: Towards a psychophysiological model for online prediction of mental workload

    OpenAIRE

    Gagnon, Jean-François; Durantin, Gauthier; Vachon, François; Causse, Mickael; Tremblay, Sébastien; Dehais, Frédéric

    2012-01-01

    Mental workload is a key factor influencing the occurrence of human error; specifically in remotely-operated vehicle operations. Both low and high mental workload has been found to disrupt performance in a nonlinear fashion at a given task; however, research that has attempted to predict individual mental workload has met with little success. The objective of the present study is to investigate the potential of the dual-task paradigm and prefrontal cortex oxygenation as online measures of men...

  3. Subsecond dopamine fluctuations in human striatum encode superposed error signals about actual and counterfactual reward.

    Science.gov (United States)

    Kishida, Kenneth T; Saez, Ignacio; Lohrenz, Terry; Witcher, Mark R; Laxton, Adrian W; Tatter, Stephen B; White, Jason P; Ellis, Thomas L; Phillips, Paul E M; Montague, P Read

    2016-01-01

    In the mammalian brain, dopamine is a critical neuromodulator whose actions underlie learning, decision-making, and behavioral control. Degeneration of dopamine neurons causes Parkinson's disease, whereas dysregulation of dopamine signaling is believed to contribute to psychiatric conditions such as schizophrenia, addiction, and depression. Experiments in animal models suggest the hypothesis that dopamine release in human striatum encodes reward prediction errors (RPEs) (the difference between actual and expected outcomes) during ongoing decision-making. Blood oxygen level-dependent (BOLD) imaging experiments in humans support the idea that RPEs are tracked in the striatum; however, BOLD measurements cannot be used to infer the action of any one specific neurotransmitter. We monitored dopamine levels with subsecond temporal resolution in humans (n = 17) with Parkinson's disease while they executed a sequential decision-making task. Participants placed bets and experienced monetary gains or losses. Dopamine fluctuations in the striatum fail to encode RPEs, as anticipated by a large body of work in model organisms. Instead, subsecond dopamine fluctuations encode an integration of RPEs with counterfactual prediction errors, the latter defined by how much better or worse the experienced outcome could have been. How dopamine fluctuations combine the actual and counterfactual is unknown. One possibility is that this process is the normal behavior of reward processing dopamine neurons, which previously had not been tested by experiments in animal models. Alternatively, this superposition of error terms may result from an additional yet-to-be-identified subclass of dopamine neurons. PMID:26598677

  4. A data-based method for assessing and reducing human error to improve operational performance

    International Nuclear Information System (INIS)

    This paper describes the development of a technique designed to assist engineers not only to assess the likelihood and impact of human unreliability but to apply human factors technology to optimize overall systems design. It explores the identity and magnitude of error-producing factors and presents a battery of defensive measures which can be applied to combat their effects. The method has been applied in a variety of industrial situations and assessed by several enterprises as an aid to cost-effective design and operational decision making. The current indications are that the method produces fairly consistent predictions which assessors have found helpful in both an absolute and relative sense

  5. DISTANCE MEASURING MODELING AND ERROR ANALYSIS OF DUAL CCD VISION SYSTEM SIMULATING HUMAN EYES AND NECK

    Institute of Scientific and Technical Information of China (English)

    Wang Xuanyin; Xiao Baoping; Pan Feng

    2003-01-01

    A dual-CCD simulating human eyes and neck (DSHEN) vision system is put forward. Its structure and principle are introduced. The DSHEN vision system can perform some movements simulating human eyes and neck by means of four rotating joints, and realize precise object recognizing and distance measuring in all orientations. The mathematic model of the DSHEN vision system is built, and its movement equation is solved. The coordinate error and measure precision affected by the movement parameters are analyzed by means of intersection measuring method. So a theoretic foundation for further research on automatic object recognizing and precise target tracking is provided.

  6. Restenosis: Intracoronary Brachytherapy.

    Science.gov (United States)

    Drachman, Douglas E.; Simon, Daniel I.

    2002-04-01

    Though interventional strategies have revolutionized the management of patients with symptomatic coronary artery disease, in-stent restenosis has emerged as the single most important limitation of long-term success following percutaneous coronary intervention. Once present, in-stent restenosis is extraordinarily difficult to treat, with conventional revascularization techniques failing in 50% to 80% of patients. Intracoronary radiation, or brachytherapy, targets cellular proliferation within the culprit neointima. Clinical trials have demonstrated that brachytherapy is a highly effective treatment for in-stent restenosis, reducing angiographic restenosis by 50% to 60% and the need for target vessel revascularization by 40% to 50%. The benefits of intracoronary brachytherapy may be particularly pronounced in certain patient subgroups (eg, those with diabetes, long lesions, or lesions in saphenous vein bypass grafts), but comes at the cost of an increased rate of late stent thrombosis and the need for extended antiplatelet therapy. The role of brachytherapy in the arsenal of the interventional cardiologist will continue to evolve, particularly in light of the unprecedented recent advances with the use of drug-eluting stents for restenosis prevention. PMID:11858773

  7. ATHEANA: A Technique for Human Error Analysis: An Overview of Its Methodological Basis

    International Nuclear Information System (INIS)

    The U.S. NRC has developed a new human reliability analysis (HRA) method, called A Technique for Human Event Analysis (ATHEANA), to provide a way of modeling the so-called 'errors of commission' - that is, situations in which operators terminate or disable engineered safety features (ESFs) or similar equipment during accident conditions, thereby putting the plant at an increased risk of core damage. In its reviews of operational events, NRC has found that these errors of commission occur with a relatively high frequency (as high as 2 or 3 per year), but are noticeably missing from the scope of most current probabilistic risk assessments (PRAs). This new method was developed through a formalized approach that describes what can occur when operators behave rationally but have inadequate knowledge or poor judgement. In particular, the method is based on models of decision-making and response planning that have been used extensively in the aviation field, and on the analysis of major accidents in both the nuclear and non-nuclear fields. Other papers at this conference present summaries of these event analyses in both the nuclear and non-nuclear fields. This paper presents an overview of ATHEANA and summarizes how the method structures the analysis of operationally significant events, and helps HRA analysts identify and model potentially risk-significant errors of commission in plant PRAs. (authors)

  8. ATHEANA: open-quotes a technique for human error analysisclose quotes entering the implementation phase

    International Nuclear Information System (INIS)

    Probabilistic Risk Assessment (PRA) has become an increasingly important tool in the nuclear power industry, both for the Nuclear Regulatory Commission (NRC) and the operating utilities. The NRC recently published a final policy statement, SECY-95-126, encouraging the use of PRA in regulatory activities. Human reliability analysis (HRA), while a critical element of PRA, has limitations in the analysis of human actions in PRAs that have long been recognized as a constraint when using PRA. In fact, better integration of HRA into the PRA process has long been a NRC issue. Of particular concern, has been the omission of errors of commission - those errors that are associated with inappropriate interventions by operators with operating systems. To address these concerns, the NRC identified the need to develop an improved HRA method, so that human reliability can be better represented and integrated into PRA modeling and quantification. The purpose of the Brookhaven National Laboratory (BNL) project, entitled 'Improved HRA Method Based on Operating Experience' is to develop a new method for HRA which is supported by the analysis of risk-significant operating experience. This approach will allow a more realistic assessment and representation of the human contribution to plant risk, and thereby increase the utility of PRA. The project's completed, ongoing, and future efforts fall into four phases: (1) Assessment phase (FY 92/93); (2) Analysis and Characterization phase (FY 93/94); (3) Development phase (FY 95/96); and (4) Implementation phase (FY 96/97 ongoing)

  9. Effective use of pre-job briefing as tool for the prevention of human error

    International Nuclear Information System (INIS)

    There is a fundamental demand to minimise the risks for workers and facilities while executing maintenance work. To ensure that facilities are secure and reliable, any deviation from normal operation behaviour has to be avoided. Accurate planning is the basis for minimising mistakes and making work more secure. All workers involved should understand how the work should be done and what is expected to avoid human errors. Especially in nuclear power plants, the human performance tools (HPT) have proved to be an effective instrument to minimise human errors. These human performance tools consist of numerous different tools that complement each other (e.g. pre-job briefing). The safety culture of the plants is also characterised by these tools. The choice of using the right HP-Tool is often a difficult task for the work planer. On the one hand, he wants to avoid mistakes during the execution of work but on the other hand he does not want to irritate the workers with unnecessary requirements. The proposed concept uses a simple risk analysis to take into account the complexity of the task, the experience of the past and the consequences of failure in to account. One main result of this risk analysis is a recommendation of the detailing of the pre-job briefing, to reduce the risks for the involved staff to a minimum.

  10. Results of a Nuclear Power Plant Application of a New Technique for Human Error Analysis (ATHEANA)

    International Nuclear Information System (INIS)

    A new method to analyze human errors has been demonstrated at a pressurized water reactor (PWR) nuclear power plant. This was the first application of the new method referred to as A Technique for Human Error Analysis (ATHEANA). The main goals of the demonstration were to test the ATHEANA process as described in the frame-of-reference manual and the implementation guideline, test a training package developed for the method, test the hypothesis that plant operators and trainers have significant insight into the error-forcing-contexts (EFCs) that can make unsafe actions (UAs) more likely, and to identify ways to improve the method and its documentation. A set of criteria to evaluate the 'success' of the ATHEANA method as used in the demonstration was identified. A human reliability analysis (HRA) team was formed that consisted of an expert in probabilistic risk assessment (PRA) with some background in HRA (not ATHEANA) and four personnel from the nuclear power plant. Personnel from the plant included two individuals from their PRA staff and two individuals from their training staff. Both individuals from training are currently licensed operators and one of them was a senior reactor operator 'on shift' until a few months before the demonstration. The demonstration was conducted over a 5-month period and was observed by members of the Nuclear Regulatory Commission's ATHEANA development team, who also served as consultants to the HRA team when necessary. Example results of the demonstration to date, including identified human failure events (HFEs), UAs, and EFCs are discussed. Also addressed is how simulator exercises are used in the ATHEANA demonstration project. (authors)

  11. Results of a nuclear power plant application of A New Technique for Human Error Analysis (ATHEANA)

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, D.W.; Forester, J.A. [Sandia National Labs., Albuquerque, NM (United States); Bley, D.C. [Buttonwood Consulting, Inc. (United States)] [and others

    1998-03-01

    A new method to analyze human errors has been demonstrated at a pressurized water reactor (PWR) nuclear power plant. This was the first application of the new method referred to as A Technique for Human Error Analysis (ATHEANA). The main goals of the demonstration were to test the ATHEANA process as described in the frame-of-reference manual and the implementation guideline, test a training package developed for the method, test the hypothesis that plant operators and trainers have significant insight into the error-forcing-contexts (EFCs) that can make unsafe actions (UAs) more likely, and to identify ways to improve the method and its documentation. A set of criteria to evaluate the success of the ATHEANA method as used in the demonstration was identified. A human reliability analysis (HRA) team was formed that consisted of an expert in probabilistic risk assessment (PRA) with some background in HRA (not ATHEANA) and four personnel from the nuclear power plant. Personnel from the plant included two individuals from their PRA staff and two individuals from their training staff. Both individuals from training are currently licensed operators and one of them was a senior reactor operator on shift until a few months before the demonstration. The demonstration was conducted over a 5-month period and was observed by members of the Nuclear Regulatory Commission`s ATHEANA development team, who also served as consultants to the HRA team when necessary. Example results of the demonstration to date, including identified human failure events (HFEs), UAs, and EFCs are discussed. Also addressed is how simulator exercises are used in the ATHEANA demonstration project.

  12. Multidisciplinary framework for human reliability analysis with an application to errors of commission and dependencies

    Energy Technology Data Exchange (ETDEWEB)

    Barriere, M.T.; Luckas, W.J. [Brookhaven National Lab., Upton, NY (United States); Wreathall, J. [Wreathall (John) and Co., Dublin, OH (United States); Cooper, S.E. [Science Applications International Corp., Reston, VA (United States); Bley, D.C. [PLG, Inc., Newport Beach, CA (United States); Ramey-Smith, A. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology

    1995-08-01

    Since the early 1970s, human reliability analysis (HRA) has been considered to be an integral part of probabilistic risk assessments (PRAs). Nuclear power plant (NPP) events, from Three Mile Island through the mid-1980s, showed the importance of human performance to NPP risk. Recent events demonstrate that human performance continues to be a dominant source of risk. In light of these observations, the current limitations of existing HRA approaches become apparent when the role of humans is examined explicitly in the context of real NPP events. The development of new or improved HRA methodologies to more realistically represent human performance is recognized by the Nuclear Regulatory Commission (NRC) as a necessary means to increase the utility of PRAS. To accomplish this objective, an Improved HRA Project, sponsored by the NRC`s Office of Nuclear Regulatory Research (RES), was initiated in late February, 1992, at Brookhaven National Laboratory (BNL) to develop an improved method for HRA that more realistically assesses the human contribution to plant risk and can be fully integrated with PRA. This report describes the research efforts including the development of a multidisciplinary HRA framework, the characterization and representation of errors of commission, and an approach for addressing human dependencies. The implications of the research and necessary requirements for further development also are discussed.

  13. Multidisciplinary framework for human reliability analysis with an application to errors of commission and dependencies

    International Nuclear Information System (INIS)

    Since the early 1970s, human reliability analysis (HRA) has been considered to be an integral part of probabilistic risk assessments (PRAs). Nuclear power plant (NPP) events, from Three Mile Island through the mid-1980s, showed the importance of human performance to NPP risk. Recent events demonstrate that human performance continues to be a dominant source of risk. In light of these observations, the current limitations of existing HRA approaches become apparent when the role of humans is examined explicitly in the context of real NPP events. The development of new or improved HRA methodologies to more realistically represent human performance is recognized by the Nuclear Regulatory Commission (NRC) as a necessary means to increase the utility of PRAS. To accomplish this objective, an Improved HRA Project, sponsored by the NRC's Office of Nuclear Regulatory Research (RES), was initiated in late February, 1992, at Brookhaven National Laboratory (BNL) to develop an improved method for HRA that more realistically assesses the human contribution to plant risk and can be fully integrated with PRA. This report describes the research efforts including the development of a multidisciplinary HRA framework, the characterization and representation of errors of commission, and an approach for addressing human dependencies. The implications of the research and necessary requirements for further development also are discussed

  14. Post-event human decision errors: operator action tree/time reliability correlation

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R E; Fragola, J; Wreathall, J

    1982-11-01

    This report documents an interim framework for the quantification of the probability of errors of decision on the part of nuclear power plant operators after the initiation of an accident. The framework can easily be incorporated into an event tree/fault tree analysis. The method presented consists of a structure called the operator action tree and a time reliability correlation which assumes the time available for making a decision to be the dominating factor in situations requiring cognitive human response. This limited approach decreases the magnitude and complexity of the decision modeling task. Specifically, in the past, some human performance models have attempted prediction by trying to emulate sequences of human actions, or by identifying and modeling the information processing approach applicable to the task. The model developed here is directed at describing the statistical performance of a representative group of hypothetical individuals responding to generalized situations.

  15. Post-event human decision errors: operator action tree/time reliability correlation

    International Nuclear Information System (INIS)

    This report documents an interim framework for the quantification of the probability of errors of decision on the part of nuclear power plant operators after the initiation of an accident. The framework can easily be incorporated into an event tree/fault tree analysis. The method presented consists of a structure called the operator action tree and a time reliability correlation which assumes the time available for making a decision to be the dominating factor in situations requiring cognitive human response. This limited approach decreases the magnitude and complexity of the decision modeling task. Specifically, in the past, some human performance models have attempted prediction by trying to emulate sequences of human actions, or by identifying and modeling the information processing approach applicable to the task. The model developed here is directed at describing the statistical performance of a representative group of hypothetical individuals responding to generalized situations

  16. Development of the Human Error Management Criteria and the Job Aptitude Evaluation Criteria for Rail Safety Personnel

    International Nuclear Information System (INIS)

    It has been estimated that up to 90% of all workplace accidents have human error as a cause. Human error has been widely recognized as a key factor in almost all the highly publicized accidents, including Daegu subway fire of February 18, 2003 killed 198 people and injured 147. Because most human behavior is 'unintentional', carried out automatically, root causes of human error should be carefully investigated and regulated by a legal authority. The final goal of this study is to set up some regulatory guidance that are supposed to be used by the korean rail organizations related to safety managements and the contents are : - to develop the regulatory guidance for managing human error, - to develop the regulatory guidance for managing qualifications of rail drivers - to develop the regulatory guidance for evaluating the aptitude of the safety-related personnel

  17. HUMAN ERRORS: THEIR PSYCHOPHYSICAL BASES AND THE PROPRIOCEPTIVE DIAGNOSIS OF TEMPERAMENT AND CHARACTER (DP-TC) AS A TOOL FOR MEASURING

    OpenAIRE

    TOUS RAL JOSEP MARIA; Liutsko, Liudmila

    2014-01-01

    Human error is commonly differentiated into three different types. These are: errors in perception, errors in decision and errors in sensation. This analysis is based on classical psychophysics (Fechner, 1860) and describes the errors of detection and perception. De-cision-making errors are evaluated in terms of the theory of signal detection (McNicholson, 1974), and errors of sensation or sensitivity are evaluated in terms of proprioceptive information (van Beers, 2001). Each of these stages...

  18. New classification of operators' human errors at overseas nuclear power plants and preparation of easy-to-use case sheets

    International Nuclear Information System (INIS)

    At nuclear power plants, plant operators examine other human error cases, including those that occurred at other plants, so that they can learn from such experiences and avoid making similar errors again. Although there is little data available on errors made at domestic plants, nuclear operators in foreign countries are reporting even minor irregularities and signs of faults, and a large amount of data on human errors at overseas plants could be collected and examined. However, these overseas data have not been used effectively because most of them are poorly organized or not properly classified and are often hard to understand. Accordingly, we carried out a study on the cases of human errors at overseas power plants in order to help plant personnel clearly understand overseas experiences and avoid repeating similar errors, The study produced the following results, which were put to use at nuclear power plants and other facilities. (1) ''One-Point-Advice'' refers to a practice where a leader gives pieces of advice to his team of operators in order to prevent human errors before starting work. Based on this practice and those used in the aviation industry, we have developed a new method of classifying human errors that consists of four basic actions and three applied actions. (2) We used this new classification method to classify human errors made by operators at overseas nuclear power plants. The results show that the most frequent errors caused not by operators themselves but due to insufficient team monitoring, for which superiors and/or their colleagues were responsible. We therefore analyzed and classified possible factors contributing to insufficient team monitoring, and demonstrated that the frequent errors have also occurred at domestic power plants. (3) Using the new classification formula, we prepared a human error case sheets that is easy for plant personnel to understand. The sheets are designed to make data more understandable and easier to remember

  19. Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Samia de Freitas, E-mail: samiabrandao@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Campos, Tarcisio Passos Ribeiro de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2013-06-15

    Objective: comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and methods: simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results: intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively, on the healthy tissue, on the balloon periphery and on the /{sub 1} and /{sub 2} tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively on the healthy tissue, on the target tumor and on the /{sub 1} and /{sub 2} infiltration zones. Conclusion: Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones. (author)

  20. Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

    Directory of Open Access Journals (Sweden)

    Samia de Freitas Brandao

    2013-07-01

    Full Text Available Objective Comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and Methods Simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results Intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h-1.p-1.s, respectively, on the healthy tissue, on the balloon periphery and on the I 1 and I 2 tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h-1.p-1.s, respectively on the healthy tissue, on the target tumor and on the I 1 and I 2 infiltration zones. Conclusion Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones.

  1. Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

    International Nuclear Information System (INIS)

    Objective: comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and methods: simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results: intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h-1.p-1.s, respectively, on the healthy tissue, on the balloon periphery and on the /1 and /2 tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h-1.p-1.s, respectively on the healthy tissue, on the target tumor and on the /1 and /2 infiltration zones. Conclusion: Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones. (author)

  2. Determining The Factors Causing Human Error Deficiencies At A Public Utility Company

    Directory of Open Access Journals (Sweden)

    F. W. Badenhorst

    2004-11-01

    Full Text Available According to Neff (1977, as cited by Bergh (1995, the westernised culture considers work important for industrial mental health. Most individuals experience work positively, which creates a positive attitude. Should this positive attitude be inhibited, workers could lose concentration and become bored, potentially resulting in some form of human error. The aim of this research was to determine the factors responsible for human error events, which lead to power supply failures at Eskom power stations. Proposals were made for the reduction of these contributing factors towards improving plant performance. The target population was 700 panel operators in Eskom’s Power Generation Group. The results showed that factors leading to human error can be reduced or even eliminated. Opsomming Neff (1977 soos aangehaal deur Bergh (1995, skryf dat in die westerse kultuur werk belangrik vir bedryfsgeestesgesondheid is. Die meeste persone ervaar werk as positief, wat ’n positiewe gesindheid kweek. Indien hierdie positiewe gesindheid geïnhibeer word, kan dit lei tot ’n gebrek aan konsentrasie by die werkers. Werkers kan verveeld raak en dit kan weer lei tot menslike foute. Die doel van hierdie navorsing is om die faktore vas te stel wat tot menslike foute lei, en wat bydra tot onderbrekings in kragvoorsiening by Eskom kragstasies. Voorstelle is gemaak vir die vermindering van hierdie bydraende faktore ten einde die kragaanleg se prestasie te verbeter. Die teiken-populasie was 700 paneel-operateurs in die Kragopwekkingsgroep by Eskom. Die resultate dui daarop dat die faktore wat aanleiding gee tot menslike foute wel verminder, of geëlimineer kan word.

  3. Report: Human biochemical genetics: an insight into inborn errors of metabolism

    Institute of Scientific and Technical Information of China (English)

    YU Chunli; SCOTT C. Ronald

    2006-01-01

    Inborn errors of metabolism (IEM) include a broad spectrum of defects of various gene products that affect intermediary metabolism in the body. Studying the molecular and biochemical mechanisms of those inherited disorder, systematically summarizing the disease phenotype and natural history, providing diagnostic rationale and methodology and treatment strategy comprise the context of human biochemical genetics. This session focused on: (1) manifestations of representative metabolic disorders; (2) the emergent technology and application of newborn screening of metabolic disorders using tandem mass spectrometry; (3) principles of managing IEM; (4) the concept of carrier testing aiming prevention. Early detection of patients with IEM allows early intervention and more options for treatment.

  4. Formal safety assessment and application of the navigation simulators for preventing human error in ship operations

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The International Maritime Organization (IMO) has encouraged its member countries to introduce Formal Safety Assessment (FSA) for ship operations since the end of the last century. FSA can be used through certain formal assessing steps to generate effective recommendations and cautions to control marine risks and improve the safety of ships. On the basis of the brief introduction of FSA, this paper describes the ideas of applying FSA to the prevention of human error in ship operations. It especially discusses the investigation and analysis of the information and data using navigation simulators and puts forward some suggestions for the introduction and development of the FSA research work for safer ship operations.

  5. A human error taxonomy for analysing healthcare incident reports: assessing reporting culture and its effects on safety perfomance

    DEFF Research Database (Denmark)

    Itoh, Kenji; Omata, N.; Andersen, Henning Boje

    2009-01-01

    The present paper reports on a human error taxonomy system developed for healthcare risk management and on its application to evaluating safety performance and reporting culture. The taxonomy comprises dimensions for classifying errors, for performance-shaping factors, and for the maturity of...

  6. Good people who try their best can have problems: recognition of human factors and how to minimise error.

    Science.gov (United States)

    Brennan, Peter A; Mitchell, David A; Holmes, Simon; Plint, Simon; Parry, David

    2016-01-01

    Human error is as old as humanity itself and is an appreciable cause of mistakes by both organisations and people. Much of the work related to human factors in causing error has originated from aviation where mistakes can be catastrophic not only for those who contribute to the error, but for passengers as well. The role of human error in medical and surgical incidents, which are often multifactorial, is becoming better understood, and includes both organisational issues (by the employer) and potential human factors (at a personal level). Mistakes as a result of individual human factors and surgical teams should be better recognised and emphasised. Attitudes and acceptance of preoperative briefing has improved since the introduction of the World Health Organization (WHO) surgical checklist. However, this does not address limitations or other safety concerns that are related to performance, such as stress and fatigue, emotional state, hunger, awareness of what is going on situational awareness, and other factors that could potentially lead to error. Here we attempt to raise awareness of these human factors, and highlight how they can lead to error, and how they can be minimised in our day-to-day practice. Can hospitals move from being "high risk industries" to "high reliability organisations"? PMID:26542258

  7. Inborn errors of human STAT1: allelic heterogeneity governs the diversity of immunological and infectious phenotypes.

    Science.gov (United States)

    Boisson-Dupuis, Stephanie; Kong, Xiao-Fei; Okada, Satoshi; Cypowyj, Sophie; Puel, Anne; Abel, Laurent; Casanova, Jean-Laurent

    2012-08-01

    The genetic dissection of various human infectious diseases has led to the definition of inborn errors of human STAT1 immunity of four types, including (i) autosomal recessive (AR) complete STAT1 deficiency, (ii) AR partial STAT1 deficiency, (iii) autosomal dominant (AD) STAT1 deficiency, and (iv) AD gain of STAT1 activity. The two types of AR STAT1 defect give rise to a broad infectious phenotype with susceptibility to intramacrophagic bacteria (mostly mycobacteria) and viruses (herpes viruses at least), due principally to the impairment of IFN-γ-mediated and IFN-α/β-mediated immunity, respectively. Clinical outcome depends on the extent to which the STAT1 defect decreases responsiveness to these cytokines. AD STAT1 deficiency selectively predisposes individuals to mycobacterial disease, owing to the impairment of IFN-γ-mediated immunity, as IFN-α/β-mediated immunity is maintained. Finally, AD gain of STAT1 activity is associated with autoimmunity, probably owing to an enhancement of IFN-α/β-mediated immunity. More surprisingly, it is also associated with chronic mucocutaneous candidiasis, through as yet undetermined mechanisms involving an inhibition of the development of IL-17-producing T cells. Thus, germline mutations in human STAT1 define four distinct clinical disorders. Various combinations of viral, mycobacterial and fungal infections are therefore allelic at the human STAT1 locus. These experiments of Nature neatly highlight the clinical and immunological impact of the human genetic dissection of infectious phenotypes. PMID:22651901

  8. How to Cope with the Rare Human Error Events Involved with organizational Factors in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sa Kil; Luo, Meiling; Lee, Yong Hee [Korea Atomic Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The current human error guidelines (e.g. US DOD handbooks, US NRC Guidelines) are representative tools to prevent human errors. These tools, however, have limits that they do not adapt all operating situations and circumstances such as design base events. In other words, these tools are only adapted foreseeable standardized operating situations and circumstances. In this study, our research team proposed an evidence-based approach such as UK's safety case to coping with the rare human error events such as TMI, Chernobyl, Fukushima accidents. These accidents are representative events involved with rare human errors. Our research team defined the 'rare human errors' as the follow three characterized events; Extremely low frequency Extremely high complicated structure Extremely serious damage of human life and property A safety case is a structured argument, supported by evidence, intended to justify that a system is acceptably safe. The definition by UK defense standard 00-56 issue 4 states that such an evidence-based approach can be contrast with a prescriptive approach to safety certification, which require safety to be justified using a prescribed process. Safety managements and safety regulatory activities based on safety case are effective to control organizational factors in terms of integrated safety management. Especially safety issues relevant with public acceptance are useful to provide practical evidences to the public reasonably. European Union including UK has developed the concept of engineered safety management system to deal with public acceptance using the safety case. In Korea nuclear industry, the Korean Atomic Research Institute has firstly performed a basic research to adapt the safety case in the field of radioactive waste according to the IAEA SSG-23(KAERI/TR-4497, 4531). Excepting the radioactive waste, there is no try to adapt the safety case yet. Most incidents and accidents involved human during operating NPPs have a tendency

  9. How to Cope with the Rare Human Error Events Involved with organizational Factors in Nuclear Power Plants

    International Nuclear Information System (INIS)

    The current human error guidelines (e.g. US DOD handbooks, US NRC Guidelines) are representative tools to prevent human errors. These tools, however, have limits that they do not adapt all operating situations and circumstances such as design base events. In other words, these tools are only adapted foreseeable standardized operating situations and circumstances. In this study, our research team proposed an evidence-based approach such as UK's safety case to coping with the rare human error events such as TMI, Chernobyl, Fukushima accidents. These accidents are representative events involved with rare human errors. Our research team defined the 'rare human errors' as the follow three characterized events; Extremely low frequency Extremely high complicated structure Extremely serious damage of human life and property A safety case is a structured argument, supported by evidence, intended to justify that a system is acceptably safe. The definition by UK defense standard 00-56 issue 4 states that such an evidence-based approach can be contrast with a prescriptive approach to safety certification, which require safety to be justified using a prescribed process. Safety managements and safety regulatory activities based on safety case are effective to control organizational factors in terms of integrated safety management. Especially safety issues relevant with public acceptance are useful to provide practical evidences to the public reasonably. European Union including UK has developed the concept of engineered safety management system to deal with public acceptance using the safety case. In Korea nuclear industry, the Korean Atomic Research Institute has firstly performed a basic research to adapt the safety case in the field of radioactive waste according to the IAEA SSG-23(KAERI/TR-4497, 4531). Excepting the radioactive waste, there is no try to adapt the safety case yet. Most incidents and accidents involved human during operating NPPs have a tendency

  10. Human reliability analysis of errors of commission: a review of methods and applications

    Energy Technology Data Exchange (ETDEWEB)

    Reer, B

    2007-06-15

    Illustrated by specific examples relevant to contemporary probabilistic safety assessment (PSA), this report presents a review of human reliability analysis (HRA) addressing post initiator errors of commission (EOCs), i.e. inappropriate actions under abnormal operating conditions. The review addressed both methods and applications. Emerging HRA methods providing advanced features and explicit guidance suitable for PSA are: A Technique for Human Event Analysis (ATHEANA, key publications in 1998/2000), Methode d'Evaluation de la Realisation des Missions Operateur pour la Surete (MERMOS, 1998/2000), the EOC HRA method developed by the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS, 2003), the Misdiagnosis Tree Analysis (MDTA) method (2005/2006), the Cognitive Reliability and Error Analysis Method (CREAM, 1998), and the Commission Errors Search and Assessment (CESA) method (2002/2004). As a result of a thorough investigation of various PSA/HRA applications, this paper furthermore presents an overview of EOCs (termination of safety injection, shutdown of secondary cooling, etc.) referred to in predictive studies and a qualitative review of cases of EOC quantification. The main conclusions of the review of both the methods and the EOC HRA cases are: (1) The CESA search scheme, which proceeds from possible operator actions to the affected systems to scenarios, may be preferable because this scheme provides a formalized way for identifying relatively important scenarios with EOC opportunities; (2) an EOC identification guidance like CESA, which is strongly based on the procedural guidance and important measures of systems or components affected by inappropriate actions, however should pay some attention to EOCs associated with familiar but non-procedural actions and EOCs leading to failures of manually initiated safety functions. (3) Orientations of advanced EOC quantification comprise a) modeling of multiple contexts for a given scenario, b) accounting for

  11. Human reliability analysis of errors of commission: a review of methods and applications

    International Nuclear Information System (INIS)

    Illustrated by specific examples relevant to contemporary probabilistic safety assessment (PSA), this report presents a review of human reliability analysis (HRA) addressing post initiator errors of commission (EOCs), i.e. inappropriate actions under abnormal operating conditions. The review addressed both methods and applications. Emerging HRA methods providing advanced features and explicit guidance suitable for PSA are: A Technique for Human Event Analysis (ATHEANA, key publications in 1998/2000), Methode d'Evaluation de la Realisation des Missions Operateur pour la Surete (MERMOS, 1998/2000), the EOC HRA method developed by the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS, 2003), the Misdiagnosis Tree Analysis (MDTA) method (2005/2006), the Cognitive Reliability and Error Analysis Method (CREAM, 1998), and the Commission Errors Search and Assessment (CESA) method (2002/2004). As a result of a thorough investigation of various PSA/HRA applications, this paper furthermore presents an overview of EOCs (termination of safety injection, shutdown of secondary cooling, etc.) referred to in predictive studies and a qualitative review of cases of EOC quantification. The main conclusions of the review of both the methods and the EOC HRA cases are: (1) The CESA search scheme, which proceeds from possible operator actions to the affected systems to scenarios, may be preferable because this scheme provides a formalized way for identifying relatively important scenarios with EOC opportunities; (2) an EOC identification guidance like CESA, which is strongly based on the procedural guidance and important measures of systems or components affected by inappropriate actions, however should pay some attention to EOCs associated with familiar but non-procedural actions and EOCs leading to failures of manually initiated safety functions. (3) Orientations of advanced EOC quantification comprise a) modeling of multiple contexts for a given scenario, b) accounting for

  12. Study on application of human cognition reliability model in human error in emergency response against the source blockage of high dose rate afterloading unit

    International Nuclear Information System (INIS)

    Objective: To put forward reasonable and feasible recommendations aiming at enhancing the application safety of afterloading unit, through studying the human reliability in the emergency response against the source blockage of afterloading unit. Methods: Based on the human cognition reliability model, ten operation errors during the emergency response against the source blockage of afterloading unit were analyzed and permissible time widow of emergency response operation were determined. The human error probability was calculated with the execution time of emergency response operation obtained through simulation, observation and recording. Results: The operation action, relevant permissible time window and execution time were obtained with the corresponding human error probabilities in the range 0.04-0.27. Conclusions: The human error model in emergency response against the source blockage of afterloading unit based on HCRmodel is feasible, and provides important reference basis to reduce the occurrence of potential exposure and mitigate the consequence of potential exposure. (authors)

  13. An empirical study on the basic human error probabilities for NPP advanced main control room operation using soft control

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Inseok, E-mail: nuclear82@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Ar Ryum, E-mail: arryum@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Harbi, Mohamed Ali Salem Al, E-mail: 100035556@kustar.ac.ae [Department of Nuclear Engineering, Khalifa University of Science, Technology and Research, P.O. Box 127788, Abu Dhabi (United Arab Emirates); Lee, Seung Jun, E-mail: sjlee@kaeri.re.kr [Integrated Safety Assessment Division, Korea Atomic Energy Research Institute, 150-1, Dukjin-dong, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Kang, Hyun Gook, E-mail: hyungook@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Seong, Poong Hyun, E-mail: phseong@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2013-04-15

    Highlights: ► The operation environment of MCRs in NPPs has changed by adopting new HSIs. ► The operation action in NPP Advanced MCRs is performed by soft control. ► Different basic human error probabilities (BHEPs) should be considered. ► BHEPs in a soft control operation environment are investigated empirically. ► This work will be helpful to verify if soft control has positive or negative effects. -- Abstract: By adopting new human–system interfaces that are based on computer-based technologies, the operation environment of main control rooms (MCRs) in nuclear power plants (NPPs) has changed. The MCRs that include these digital and computer technologies, such as large display panels, computerized procedures, soft controls, and so on, are called Advanced MCRs. Among the many features in Advanced MCRs, soft controls are an important feature because the operation action in NPP Advanced MCRs is performed by soft control. Using soft controls such as mouse control, touch screens, and so on, operators can select a specific screen, then choose the controller, and finally manipulate the devices. However, because of the different interfaces between soft control and hardwired conventional type control, different basic human error probabilities (BHEPs) should be considered in the Human Reliability Analysis (HRA) for advanced MCRs. Although there are many HRA methods to assess human reliabilities, such as Technique for Human Error Rate Prediction (THERP), Accident Sequence Evaluation Program (ASEP), Human Error Assessment and Reduction Technique (HEART), Human Event Repository and Analysis (HERA), Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR), Cognitive Reliability and Error Analysis Method (CREAM), and so on, these methods have been applied to conventional MCRs, and they do not consider the new features of advance MCRs such as soft controls. As a result, there is an insufficient database for assessing human reliabilities in advanced

  14. An empirical study on the basic human error probabilities for NPP advanced main control room operation using soft control

    International Nuclear Information System (INIS)

    Highlights: ► The operation environment of MCRs in NPPs has changed by adopting new HSIs. ► The operation action in NPP Advanced MCRs is performed by soft control. ► Different basic human error probabilities (BHEPs) should be considered. ► BHEPs in a soft control operation environment are investigated empirically. ► This work will be helpful to verify if soft control has positive or negative effects. -- Abstract: By adopting new human–system interfaces that are based on computer-based technologies, the operation environment of main control rooms (MCRs) in nuclear power plants (NPPs) has changed. The MCRs that include these digital and computer technologies, such as large display panels, computerized procedures, soft controls, and so on, are called Advanced MCRs. Among the many features in Advanced MCRs, soft controls are an important feature because the operation action in NPP Advanced MCRs is performed by soft control. Using soft controls such as mouse control, touch screens, and so on, operators can select a specific screen, then choose the controller, and finally manipulate the devices. However, because of the different interfaces between soft control and hardwired conventional type control, different basic human error probabilities (BHEPs) should be considered in the Human Reliability Analysis (HRA) for advanced MCRs. Although there are many HRA methods to assess human reliabilities, such as Technique for Human Error Rate Prediction (THERP), Accident Sequence Evaluation Program (ASEP), Human Error Assessment and Reduction Technique (HEART), Human Event Repository and Analysis (HERA), Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR), Cognitive Reliability and Error Analysis Method (CREAM), and so on, these methods have been applied to conventional MCRs, and they do not consider the new features of advance MCRs such as soft controls. As a result, there is an insufficient database for assessing human reliabilities in advanced

  15. ALGEBRA: ALgorithm for the heterogeneous dosimetry based on GEANT4 for BRAchytherapy

    Science.gov (United States)

    Afsharpour, H.; Landry, G.; D'Amours, M.; Enger, S.; Reniers, B.; Poon, E.; Carrier, J.-F.; Verhaegen, F.; Beaulieu, L.

    2012-06-01

    Task group 43 (TG43)-based dosimetry algorithms are efficient for brachytherapy dose calculation in water. However, human tissues have chemical compositions and densities different than water. Moreover, the mutual shielding effect of seeds on each other (interseed attenuation) is neglected in the TG43-based dosimetry platforms. The scientific community has expressed the need for an accurate dosimetry platform in brachytherapy. The purpose of this paper is to present ALGEBRA, a Monte Carlo platform for dosimetry in brachytherapy which is sufficiently fast and accurate for clinical and research purposes. ALGEBRA is based on the GEANT4 Monte Carlo code and is capable of handling the DICOM RT standard to recreate a virtual model of the treated site. Here, the performance of ALGEBRA is presented for the special case of LDR brachytherapy in permanent prostate and breast seed implants. However, the algorithm is also capable of handling other treatments such as HDR brachytherapy.

  16. Salvage Brachytherapy for Biochemically Recurrent Prostate Cancer following Primary Brachytherapy

    Science.gov (United States)

    Lacy, John M.; Wilson, William A.; Bole, Raevti; Chen, Li; Meigooni, Ali S.; Rowland, Randall G.; Clair, William H. St.

    2016-01-01

    Purpose. In this study, we evaluated our experience with salvage brachytherapy after discovery of biochemical recurrence after a prior brachytherapy procedure. Methods and Materials. From 2001 through 2012 twenty-one patients treated by brachytherapy within University of Kentucky or from outside centers developed biochemical failure and had no evidence of metastases. Computed tomography (CT) scans were evaluated; patients who had an underseeded portion of their prostate were considered for reimplantation. Results. The majority of the patients in this study (61.9%) were low risk and median presalvage PSA was 3.49 (range 17.41–1.68). Mean follow-up was 61 months. At last follow-up after reseeding, 11/21 (52.4%) were free of biochemical recurrence. There was a trend towards decreased freedom from biochemical recurrence in low risk patients (p = 0.12). International Prostate Symptom Scores (IPSS) increased at 3-month follow-up visits but decreased and were equivalent to baseline scores at 18 months. Conclusions. Salvage brachytherapy after primary brachytherapy is possible; however, in our experience the side-effect profile after the second brachytherapy procedure was higher than after the first brachytherapy procedure. In this cohort of patients we demonstrate that approximately 50% oncologic control, low risk patients appear to have better outcomes than others. PMID:27092279

  17. The effect of retinal image error update rate on human vestibulo-ocular reflex gain adaptation.

    Science.gov (United States)

    Fadaee, Shannon B; Migliaccio, Americo A

    2016-04-01

    The primary function of the angular vestibulo-ocular reflex (VOR) is to stabilise images on the retina during head movements. Retinal image movement is the likely feedback signal that drives VOR modification/adaptation for different viewing contexts. However, it is not clear whether a retinal image position or velocity error is used primarily as the feedback signal. Recent studies examining this signal are limited because they used near viewing to modify the VOR. However, it is not known whether near viewing drives VOR adaptation or is a pre-programmed contextual cue that modifies the VOR. Our study is based on analysis of the VOR evoked by horizontal head impulses during an established adaptation task. Fourteen human subjects underwent incremental unilateral VOR adaptation training and were tested using the scleral search coil technique over three separate sessions. The update rate of the laser target position (source of the retinal image error signal) used to drive VOR adaptation was different for each session [50 (once every 20 ms), 20 and 15/35 Hz]. Our results show unilateral VOR adaptation occurred at 50 and 20 Hz for both the active (23.0 ± 9.6 and 11.9 ± 9.1% increase on adapting side, respectively) and passive VOR (13.5 ± 14.9, 10.4 ± 12.2%). At 15 Hz, unilateral adaptation no longer occurred in the subject group for both the active and passive VOR, whereas individually, 4/9 subjects tested at 15 Hz had significant adaptation. Our findings suggest that 1-2 retinal image position error signals every 100 ms (i.e. target position update rate 15-20 Hz) are sufficient to drive VOR adaptation. PMID:26715411

  18. Comparison of organ doses for patients undergoing balloon brachytherapy of the breast with HDR 192Ir or electronic sources using Monte Carlo simulations in a heterogeneous human phantom

    International Nuclear Information System (INIS)

    Purpose: Accelerated partial breast irradiation via interstitial balloon brachytherapy is a fast and effective treatment method for certain early stage breast cancers. The radiation can be delivered using a conventional high-dose rate (HDR) 192Ir gamma-emitting source or a novel electronic brachytherapy (eBx) source which uses lower energy x rays that do not penetrate as far within the patient. A previous study [A. Dickler, M. C. Kirk, N. Seif, K. Griem, K. Dowlatshahi, D. Francescatti, and R. A. Abrams, ''A dosimetric comparison of MammoSite high-dose-rate brachytherapy and Xoft Axxent electronic brachytherapy,'' Brachytherapy 6, 164-168 (2007)] showed that the target dose is similar for HDR 192Ir and eBx. This study compares these sources based on the dose received by healthy organs and tissues away from the treatment site. Methods: A virtual patient with left breast cancer was represented by a whole-body, tissue-heterogeneous female voxel phantom. Monte Carlo methods were used to calculate the dose to healthy organs in a virtual patient undergoing balloon brachytherapy of the left breast with HDR 192Ir or eBx sources. The dose-volume histograms for a few organs which received large doses were also calculated. Additional simulations were performed with all tissues in the phantom defined as water to study the effect of tissue inhomogeneities. Results: For both HDR 192Ir and eBx, the largest mean organ doses were received by the ribs, thymus gland, left lung, heart, and sternum which were close to the brachytherapy source in the left breast. eBx yielded mean healthy organ doses that were more than a factor of ∼1.4 smaller than for HDR 192Ir for all organs considered, except for the three closest ribs. Excluding these ribs, the average and median dose-reduction factors were ∼28 and ∼11, respectively. The volume distribution of doses in nearby soft tissue organs that were outside the PTV were also improved with eBx. However, the maximum dose to the closest rib

  19. Procedures for using expert judgment to estimate human-error probabilities in nuclear power plant operations

    International Nuclear Information System (INIS)

    This report describes and evaluates several procedures for using expert judgment to estimate human-error probabilities (HEPs) in nuclear power plant operations. These HEPs are currently needed for several purposes, particularly for probabilistic risk assessments. Data do not exist for estimating these HEPs, so expert judgment can provide these estimates in a timely manner. Five judgmental procedures are described here: paired comparisons, ranking and rating, direct numerical estimation, indirect numerical estimation and multiattribute utility measurement. These procedures are evaluated in terms of several criteria: quality of judgments, difficulty of data collection, empirical support, acceptability, theoretical justification, and data processing. Situational constraints such as the number of experts available, the number of HEPs to be estimated, the time available, the location of the experts, and the resources available are discussed in regard to their implications for selecting a procedure for use

  20. Organizational change and human expertise in nuclear power plants: some implications for training and error prevention

    International Nuclear Information System (INIS)

    Reliability and safety are two very important goals, which depend on technical and organizational factors, but also on human expertise. How to ensure a safe functioning of a nuclear power plant in a changing context, and what might be the role and aspects of training and transfer of knowledge? These are the questions we shall deal with in this paper, on the basis of two field studies. The two field studies stress the needs for setting up case based training, which best ensure the acquisition of know-how. Furthermore, as shown by the second one, gaining expertise involves developing large repertoires of highly skilled, semi-routinized activities. Supporting expert operators not only should tackle problem solving activities but should thus also include the prevention of routine errors, which go along with skill acquisition. (orig.)

  1. Evolutionary enhancement of the SLIM-MAUD method of estimating human error rates

    International Nuclear Information System (INIS)

    The methodology described in this paper assigns plant-specific dynamic human error rates (HERs) for individual plant examinations based on procedural difficulty, on configuration features, and on the time available to perform the action. This methodology is an evolutionary improvement of the success likelihood index methodology (SLIM-MAUD) for use in systemic scenarios. It is based on the assumption that the HER in a particular situation depends of the combined effects of a comprehensive set of performance-shaping factors (PSFs) that influence the operator's ability to perform the action successfully. The PSFs relate the details of the systemic scenario in which the action must be performed according to the operator's psychological and cognitive condition

  2. The role of human error in risk analysis: Application to pre- and post-maintenance procedures of process facilities

    International Nuclear Information System (INIS)

    Human factors play an important role in the safe operation of a facility. Human factors include the systematic application of information about human characteristics and behavior to increase the safety of a process system. A significant proportion of human errors occur during the maintenance phase. However, the quantification of human error probabilities in the maintenance phase has not been given the amount of attention it deserves. This paper focuses on a human factors analysis in pre-and post- pump maintenance operations. The procedures for removing process equipment from service (pre-maintenance) and returning the equipment to service (post-maintenance) are considered for possible failure scenarios. For each scenario, human error probability is calculated for each activity using the Success Likelihood Index Method (SLIM). Consequences are also assessed in this methodology. The risk assessment is conducted for each component and the overall risk is estimated by adding individual risks. The present study is aimed at highlighting the importance of considering human error in quantitative risk analyses. The developed methodology has been applied to a case study of an offshore process facility

  3. 106Ruthenium Brachytherapy for Retinoblastoma

    International Nuclear Information System (INIS)

    Purpose: To evaluate the efficacy of 106Ru plaque brachytherapy for the treatment of retinoblastoma. Methods and Materials: We reviewed a retrospective, noncomparative case series of 39 children with retinoblastoma treated with 106Ru plaques at the Jules-Gonin Eye Hospital between October 1992 and July 2006, with 12 months of follow-up. Results: A total of 63 tumors were treated with 106Ru brachytherapy in 41 eyes. The median patient age was 27 months. 106Ru brachytherapy was the first-line treatment for 3 tumors (4.8%), second-line treatment for 13 (20.6%), and salvage treatment for 47 tumors (74.6%) resistant to other treatment modalities. Overall tumor control was achieved in 73% at 1 year. Tumor recurrence at 12 months was observed in 2 (12.5%) of 16 tumors for which 106Ru brachytherapy was used as the first- or second-line treatment and in 15 (31.9%) of 47 tumors for which 106Ru brachytherapy was used as salvage treatment. Eye retention was achieved in 76% of cases (31 of 41 eyes). Univariate and multivariate analyses revealed no statistically significant risk factors for tumor recurrence. Radiation complications included retinal detachment in 7 (17.1%), proliferative retinopathy in 1 (2.4%), and subcapsular cataract in 4 (9.7%) of 41 eyes. Conclusion: 106Ru brachytherapy is an effective treatment for retinoblastoma, with few secondary complications. Local vitreous seeding can be successfully treated with 106Ru brachytherapy

  4. HDR endobronchial brachytherapy

    International Nuclear Information System (INIS)

    Introduction: This is a restrospective study to review the palliation rate, survival rate and complications of high dose rate (HDR) endobronchial brachytherapy in the treatment of airway obstruction of recurrent lung cancer or metastasis. Material and method: Between september 1992 and may 1995 it has been treated forty (40) patients with endobronchial lesions. 38 patients with unique endobronchial lesion and 2 patients with double lesions. 32 had primary lung carcinoma: 27 with epidermoid carcinoma (1 bilateral), 2 with adenocarcinoma, 1 with small cell carcinoma, 1 with undifferentiated carcinoma and 1 with primary double (adenocarcinoma and large cell carcinoma). 8 patients had endobronchial metastasis: 2 hypernefroma, 3 breast carcinoma, 1 colon cancer, 1 seminoma and 1 Ewing sarcoma. 33 patients were male (82.5%) and 7 female (17.5%). The treatment was carried out in three weekly fractions with a dose of 750 cGy per fraction at 1 cm from the source. An afterloaded equipment was used (microselectron HDR). The most frequent sites were: right main stem bronchus 9 patients (22.5%), left main stem bronchus 7 patients (17.5%), and right middle bronchus 5 patients (12.5%). Results and discussion: The endoscopic global response assessed after three weeks was of 70%. The symptomatic response was 95% hemoptysis control, 87% dysnea control, 80% obstructive pneumonia control and 70% cough control. The minimum follow up was one year. There were three cases of massive hemoptysis and three patients developed local recurrence (one received a second brachytherapy treatment). Conclusion: HDR brachytherapy offers an excellent long term palliation for any of the obstructing symptoms, being effective in more than 70% in patients with recurrence lung primary cancer or endobronchial metastasis with a low complication rate

  5. Intra coronary brachytherapy

    International Nuclear Information System (INIS)

    Despite the initial promise of vasculopathy intervention restenosis- a consequence of the (normal) would healing process-has emerged as a major problem. Angiographic restenosis has been reported in 40-60% of patients after successful P TCA. The basic mechanism of restenosis, (acute recoil, negative remodeling and neo intimal hyperplasia), are only partially counteracted by endovascular prosthetic devices (s tents). The rate of in-s tent restenosis, which is primarily caused by neo intimal hyperplasia due to the (micro) trauma of the arterial wall by the s tent struts, has been reduced to 18-32%. Ionizing (beta or gamma) radiations has been established as a potent treatment for malignant disorders. In recent years, there has also been increasing interest among clinicians in the management of benign lesions with radiation. Over the past several years, there has been a growing body of evidence that endovascular brachytherapy has a major impact on the biology of the restenosis. It must be underlined that understanding the biology and pathophysiology of restenosis and assessing various treatment options should preferably be a team effort, with the three gracesbeing interventional cardiologist, nuclear oncologist, and industrial partners. The vast amount of data in over 20000 patients from a wide range of randomized controlled trials, has shown that brachytherapy is the only effective treatment for in-s tent restenosis. We are learning more and more about how to improve brachytherapy. While the new coated s tents that we heard about today is fascinating and extremely promising, brachytherapy still has a very important place in difficult patients, such as those with total occlusions, osti al lesions, left main lesions, multivessel disease and diabetes. Regarding to above mentioned tips, we (a research team work, in the Nuclear Research Center Of the Atomic Energy Organization Of Iran), focused on synthesis and preparation of radioactive materials for use in I c-B T. We

  6. A study on fatigue measurement of operators for human error prevention in NPPs

    International Nuclear Information System (INIS)

    The identification and the analysis of individual factor of operators, which is one of the various causes of adverse effects in human performance, is not easy in NPPs. There are work types (including shift), environment, personality, qualification, training, education, cognition, fatigue, job stress, workload, etc in individual factors for the operators. Research at the Finnish Institute of Occupational Health (FIOH) reported that a 'burn out (extreme fatigue)' is related to alcohol dependent habits and must be dealt with using a stress management program. USNRC (U.S. Nuclear Regulatory Commission) developed FFD (Fitness for Duty) for improving the task efficiency and preventing human errors. 'Managing Fatigue' of 10CFR26 presented as requirements to control operator fatigue in NPPs. The committee explained that excessive fatigue is due to stressful work environments, working hours, shifts, sleep disorders, and unstable circadian rhythms. In addition, an International Labor Organization (ILO) developed and suggested a checklist to manage fatigue and job stress. In domestic, a systematic evaluation way is presented by the Final Safety Analysis Report (FSAR) chapter 18, Human Factors, in the licensing process. However, it almost focused on the interface design such as HMI (Human Machine Interface), not individual factors. In particular, because our country is in a process of the exporting the NPP to UAE, the development and setting of fatigue management technique is important and urgent to present the technical standard and FFD criteria to UAE. And also, it is anticipated that the domestic regulatory body applies the FFD program as the regulation requirement so that a preparation for that situation is required. In this paper, advanced researches are investigated to find the fatigue measurement and evaluation methods of operators in a high reliability industry. Also, this study tries to review the NRC report and discuss the causal factors and management

  7. A study on fatigue measurement of operators for human error prevention in NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Oh Yeon; Il, Jang Tong; Meiling, Luo; Hee, Lee Young [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    The identification and the analysis of individual factor of operators, which is one of the various causes of adverse effects in human performance, is not easy in NPPs. There are work types (including shift), environment, personality, qualification, training, education, cognition, fatigue, job stress, workload, etc in individual factors for the operators. Research at the Finnish Institute of Occupational Health (FIOH) reported that a 'burn out (extreme fatigue)' is related to alcohol dependent habits and must be dealt with using a stress management program. USNRC (U.S. Nuclear Regulatory Commission) developed FFD (Fitness for Duty) for improving the task efficiency and preventing human errors. 'Managing Fatigue' of 10CFR26 presented as requirements to control operator fatigue in NPPs. The committee explained that excessive fatigue is due to stressful work environments, working hours, shifts, sleep disorders, and unstable circadian rhythms. In addition, an International Labor Organization (ILO) developed and suggested a checklist to manage fatigue and job stress. In domestic, a systematic evaluation way is presented by the Final Safety Analysis Report (FSAR) chapter 18, Human Factors, in the licensing process. However, it almost focused on the interface design such as HMI (Human Machine Interface), not individual factors. In particular, because our country is in a process of the exporting the NPP to UAE, the development and setting of fatigue management technique is important and urgent to present the technical standard and FFD criteria to UAE. And also, it is anticipated that the domestic regulatory body applies the FFD program as the regulation requirement so that a preparation for that situation is required. In this paper, advanced researches are investigated to find the fatigue measurement and evaluation methods of operators in a high reliability industry. Also, this study tries to review the NRC report and discuss the causal factors and

  8. Validating THERP: Assessing the scope of a full-scale validation of the Technique for Human Error Rate Prediction

    International Nuclear Information System (INIS)

    Highlights: • We assess the requirements for a full-scale experimental validation of the THERP HRA method. • Two estimators are introduced to reduce the number of opportunities for error that must be observed. • We test these estimators with computer-generated data. • We conduct a pilot experiment in a full-scope, digital nuclear power plant simulator. • A powerful, partial-scope validation of the THERP method could be completed in 40 h of observing operators. - Abstract: Science-based Human Reliability Analysis (HRA) seeks to experimentally validate HRA methods in simulator studies. Emphasis is on validating the internal components of the HRA method, rather than the validity and consistency of the final results of the method. In this paper, we assess the requirements for a simulator study validation of the Technique for Human Error Rate Prediction (THERP), a foundational HRA method. The aspects requiring validation include the tables of Human Error Probabilities (HEPs), the treatment of stress, and the treatment of dependence between tasks. We estimate the sample size, n, required to obtain statistically significant error rates for validating HEP values, and the number of observations, m, that constitute one observed error rate for each HEP value. We develop two methods for estimating the mean error rate using few observations. The first method uses the median error rate, and the second method is a Bayesian estimator of the error rate based on the observed errors and the number of observations. Both methods are tested using computer-generated data. We also conduct a pilot experiment in The Ohio State University’s Nuclear Power Plant Simulator Facility. Student operators perform a maintenance task in a BWR simulator. Errors are recorded, and error rates are compared to the THERP-predicted error rates. While the observed error rates are generally consistent with the THERP HEPs, further study is needed to provide confidence in these results as the pilot

  9. Errors in Expected Human Losses Due to Incorrect Seismic Hazard Estimates

    Science.gov (United States)

    Wyss, M.; Nekrasova, A.; Kossobokov, V. G.

    2011-12-01

    are comparable with the observations. The difference between FGSHAP and Festim is used here as a quantitative measure of the error in expected risk to humans, resulting from the GSHAP hazard estimates. We find that the expected fatalities and number of injured are underestimated by GSHAP by a factor of 200 (median) and 700 (average) for earthquakes M≥6.9. FGSHAP can be considered approximately correct for the two smallest earthquakes (Bam, M6.8, 2003; Yogyakarta, M6.3, 2006), where the factor of underestimation is two. As a second measure of the inadequacy of GSHAP hazard estimates, we use the difference in the number of people affected as expected, NGSHAP, with the number estimated for the events that occurred, Nestim. The ratio Nestim/Ngshap equals 13 (median) and 340 (average) for the large events. Thus, we conclude that the earthquake risk to humans estimated based on GSHAP maps of PGA was underestimated at the locations of recent large disastrous earthquakes by more than two orders of magnitude.

  10. 21 CFR 892.5730 - Radionuclide brachytherapy source.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radionuclide brachytherapy source. 892.5730 Section 892.5730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5730 Radionuclide...

  11. Human Error Prediction and Countermeasures based on CREAM in Loading and Storage Phase of Spent Nuclear Fuel (SNF)

    International Nuclear Information System (INIS)

    With the steady demands for nuclear power energy in Korea, the amount of accumulated SNF has inevitably increased year by year. Thus far, SNF has been on-site transported from one unit to a nearby unit or an on-site dry storage facility. In the near future, as the amount of SNF generated approaches the capacity of these facilities, a percentage of it will be transported to another SNF storage facility. In the process of transporting SNF, human interactions involve inspecting and preparing the cask and spent fuel, loading the cask, transferring the cask and storage or monitoring the cask, etc. So, human actions play a significant role in SNF transportation. In analyzing incidents that have occurred during transport operations, several recent studies have indicated that 'human error' is a primary cause. Therefore, the objectives of this study are to predict and identify possible human errors during the loading and storage of SNF. Furthermore, after evaluating human error for each process, countermeasures to minimize human error are deduced

  12. Calibration of brachytherapy sources. Guidelines on standardized procedures for the calibration of brachytherapy sources at Secondary Standard Dosimetry Laboratories (SSDLs) and hospitals

    International Nuclear Information System (INIS)

    Today, irradiation by brachytherapy is considered an essential part of the treatment for almost all the sites of cancer. With the improved localization techniques and treatment planning systems, it is now possible to have precise and reproducible dose delivery. However, the desired clinical results can only be achieved with a good clinical and dosimetric practice, i.e. with the implementation of a comprehensive quality assurance (QA) programme which includes detailed quality control procedures. As summarized in the present report, accidents in brachytherapy treatments have been caused due to the lack of traceable calibration of the sources, due to the incorrect use of quantities and units, or errors made in the dose calculation procedure. The International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources has established a requirement on the calibration of sources used for medical exposure. For sources used in brachytherapy treatments, a calibration traceable to a standards dosimetry laboratory is required. The present report deals with the calibration of brachytherapy sources and related quality control (QC) measurements, QC of ionization chambers and safety aspects related to the calibration procedures. It does not include safety aspects related to the clinical use of brachytherapy sources, which have been addressed in a recent IAEA publication, IAEA-TECDOC-1040, 'Design and Implementation of a Radiotherapy Programme: Clinical, Medical Physics, Radiation Protection and Safety Aspects'. The procedures recommended in this report yield traceability to internationally accepted standards. It must be realized, however, that a comprehensive QA programme for brachytherapy cannot rest on source calibration alone, but must ensure QC of all the equipment and techniques that are used for the dose delivery to the patient. The present publication incorporates the reports of several consultants meetings in the field of

  13. Brachytherapy- past, present and future

    International Nuclear Information System (INIS)

    Discovery of radioactivity by Henry Becquerel and radium by Madame and Pierre Curie was probably the greatest event of 19th century in the field of medical science. Radium was used for brachytherapy as early as 1901. Today almost every organ is amenable to brachytherapy procedure. High dose rate remote afterloading systems have increased the patients comfort and complete radiation protection to the staff during treatment. Computers have not only improved the precision of treatment but also made 3 D conformal brachytherapy possible. As the goal of cancer management is changing from just life preservation to organ and function preservation without compromising cure rate, the role of brachytherapy is becoming more and more prominent. Intensive efforts will be needed to meet with the future challenges. (author). 13 refs

  14. Human error probability evaluation as part of reliability analysis of digital protection system of advanced pressurized water reactor - APR 1400

    International Nuclear Information System (INIS)

    A case of study on human reliability analysis has been performed as part of reliability analysis of digital protection system of the reactor automatically actuates the shutdown system of the reactor when demanded. However, the safety analysis takes credit for operator action as a diverse mean for tripping the reactor for, though a low probability, ATWS scenario. Based on the available information two cases, viz., human error in tripping the reactor and calibration error for instrumentations in protection system, have been analyzed. Wherever applicable a parametric study has also been performed

  15. New Brachytherapy Standards Paradigm Shift

    International Nuclear Information System (INIS)

    The absorbed dose to water rate at short distances in water is the quantity of interest for dosimetry in radiotherapy, but no absorbed dose to water primary standards have been available to date for dosimetry of brachytherapy sources. Currently, the procedures to determine the absorbed dose imparted to the patient in brachytherapy treatments are based on measurements traceable to air kerma standards. These procedures are affected by an uncertainty that is larger than the limit recommended by the IAEA dosimetry protocol (IAEA TRS 398 (2000)). Based on this protocol, the goal for the uncertainty of the dose delivered to the target volume should be within 5% (at the level of one standard deviation) to assure the effectiveness of a radiotherapy treatment. The international protocols for the calibration of brachytherapy gamma ray sources are based on the reference air kerma rate or the air kerma strength. The absorbed dose to water, in water at the reference position around a brachytherapy source is then calculated by applying the formalism of the protocols based on a conversion constant, the dose rate constant Λ, specific for the characteristics and geometry of the brachytherapy source. The determination of this constant relies on Monte Carlo simulations and relative measurements performed with passive dosimeters, and therefore it is typically affected by large uncertainties, larger than 5% (at the level of one standard deviation). The conversion procedure needed for brachytherapy dosimetry is a source of additional uncertainty on the final value of the absorbed dose imparted to the patient. It is due to a lack of metrology standards that makes dosimetry of brachytherapy sources less accurate than dosimetry of external radiation beams produced by 60Co sources and accelerators currently used in external beam radiotherapy. This paper reviews the current developments of absorbed dose to water primary standards for brachytherapy and the rationale for the choice of the

  16. Brachytherapy in childhood rhabdomyosarcoma treatment

    International Nuclear Information System (INIS)

    A retrospective study of 21 children with rhabdomyosarcoma treated by brachytherapy to the primary site of the tumor at the Radiotherapy Department of the A.C.Camargo Hospital between january/1980 to june/1993 was undertaken. The main objectives were to comprove the utility of brachytherapy in childhood rhabdomyosarcoma, to evaluate the local control and survival, in association with chemotherapy, to analyze the late effects of the treatment and to determinate the preferential technique to each clinical situation. All patients received brachytherapy to the tumor site. The radioactive isotopes employed were Gold198, Cesium137 and Iridium192. The brachytherapy techniques depended on the tumor site, period of treatment, availability of the radioactive material and stage of the disease. Patients treated exclusively by brachytherapy received 40 Gy to 60 Gy. When brachytherapy was associated with external radiotherapy the dose ranged from 20 Gy to 40 Gy. Local control was achieved in 18 of 20 patients (90%). The global survival and local control survival rates were 61.9% (13/21 patients) and 72,2% (13/18 patients) respectively. (author)

  17. Detailed semantic analyses of human error incidents occurring at domestic nuclear power plants to fiscal year 2000

    International Nuclear Information System (INIS)

    Analysing and evaluating observed cases of human error incidents with the emphasis on human factors and behavior involved was essential for preventing recurrence of those. CRIEPI has been conducting detailed and structures analyses of all incidents reported during last 35 year based on J-HPES, from the beginning of the first Tokai nuclear power operation till fiscal year of 2000, in which total 212 human error cases are identified. Results obtained by the analyses have been stored into the J-HPES data-base. This summarized the semantic analyses on all case-studies stored in the above data-base to grasp the practical and concrete contents and trend of more frequently observed human errors (as are called trigger actions here), causal factors and preventive measures. These semantic analyses have been executed by classifying all those items into some categories that could be considered as having almost the same meaning using the KJ method. Followings are obtained typical results by above analyses: (1) Trigger action-Those could be classified into categories of operation or categories of maintenance. Operational timing errors' and 'operational quantitative errors' were major actions in trigger actions of operation, those occupied about 20% among all actions. At trigger actions of maintenance, 'maintenance quantitative error' were major actions, those occupied quarter among all actions; (2) Causal factor- 'Human internal status' were major factors, as in concrete factors, those occupied 'improper persistence' and 'lack of knowledge'; (3) Preventive measure-Most frequent measures got were job management changes in procedural software improvements, which was from 70% to 80%. As for preventive measures of operation, software improvements have been implemented on 'organization and work practices' and 'individual consciousness'. Concerning preventive measures of maintenance, improvements have been implemented on 'organization and work practices'. (author)

  18. The Activity Check of Brachytherapy Isotope

    International Nuclear Information System (INIS)

    An isotope Ir-192, which is used in brachytherapy depends on import in whole quantities. There are a few ways for its activity. measurement using Welltype chamber or the way to rely on authentic decay table of manufacturer. In-air dosimetry using Farmer Chamber, etc. In this paper, let me introduce the way using Farmer chamber which is easier and simple. With the Farmer chamber and source calibration jig, take a measurement the activity of an isotope Ir-192 and compare the value with the value from decay table of manufacturer and check the activity of source. The result of measurement, compared the value from decay table, by ±2.1. (which belongs to recommendable value for AAPM ±5% as difference of error range). It is possible to use on clinical medicine. With the increase in use of brachytherapy, the increase of import is essential. And an accurate activity check of source is compulsory. For the activity check of source, it was possible to use Farmer chamber and source calibration jig without additional purchase of Well type chamber.

  19. A Preliminary Study on the Measures to Assess the Organizational Safety: The Cultural Impact on Human Error Potential

    International Nuclear Information System (INIS)

    The Fukushima I nuclear accident following the Tohoku earthquake and tsunami on 11 March 2011 occurred after twelve years had passed since the JCO accident which was caused as a result of an error made by JCO employees. These accidents, along with the Chernobyl accident, associated with characteristic problems of various organizations caused severe social and economic disruptions and have had significant environmental and health impact. The cultural problems with human errors occur for various reasons, and different actions are needed to prevent different errors. Unfortunately, much of the research on organization and human error has shown widely various or different results which call for different approaches. In other words, we have to find more practical solutions from various researches for nuclear safety and lead a systematic approach to organizational deficiency causing human error. This paper reviews Hofstede's criteria, IAEA safety culture, safety areas of periodic safety review (PSR), teamwork and performance, and an evaluation of HANARO safety culture to verify the measures used to assess the organizational safety

  20. An Enhancement of Campaign Posters for Human Error Prevention in NPPs

    International Nuclear Information System (INIS)

    Accidents in high reliability systems such as nuclear power plants (NPPs) give rise to not only a loss of property and life, but also social problems. One of the most frequently used techniques to grasp the current situation for hazard factors in the NPPs is an event investigation analysis based on the INPO's Human Performance Enhancement System (HPES), and the Korean Human Performance Enhancement System (K-HPES) in Korea, respectively. There are many methods and approaches for an HE assessment that is valuable for investigating the causes of undesirable events and counter-plans to prevent their recurrence in the NPPs. They differ from each other according to the objectives of the analysis; the explanation of the event, the investigation of the causes, the allocation of the responsibility, and the establishment of the counter-plan. Event databases include their own events and information from various sources such as the IAEA, regulatory bodies, and also from the INPO and WANO. As many as 111 reactor trips have occurred in the past 5 years ('01∼'05), and 26 cases of them have occurred due to HE. The trend of human error rate didn't decrease in 2004, so the KHNP started to make efforts to decrease HEs. The KHNP created as many as 40 posters for human performance improvement in 2006. The INPO has been using a traditional form of poster; additionally, the Central Research Institute of Electric Power Industry (CRIEPI) developed a type of caution report. The caution report is comprised of a poster name, a serial number, a figure, work situations, the point at issue, and a countermeasure. The preceding posters which KHNP developed in 2006 give a message about specific information related to HE events. However, it is not enough to arouse interest in the effectiveness of the posters because most people are favorably disposed toward a simple poster with many illustrations. Therefore, we stressed the need for worker's receptiveness rather than notification of information

  1. Methodical errors of measurement of the human body tissues electrical parameters

    OpenAIRE

    Antoniuk, O.; Pokhodylo, Y.

    2015-01-01

    Sources of methodical measurement errors of immitance parameters of biological tissues are described. Modeling measurement errors of RC-parameters of biological tissues equivalent circuits into the frequency range is analyzed. Recommendations on the choice of test signal frequency for measurement of these elements is provided.

  2. Management and Evaluation System on Human Error, Licence Requirements, and Job-aptitude in Rail and the Other Industries

    Energy Technology Data Exchange (ETDEWEB)

    Koo, In Soo; Suh, S. M.; Park, G. O. (and others)

    2006-07-15

    Rail system is a system that is very closely related to the public life. When an accident happens, the public using this system should be injured or even be killed. The accident that recently took place in Taegu subway system, because of the inappropriate human-side task performance, showed demonstratively how its results could turn out to be tragic one. Many studies have shown that the most cases of the accidents have occurred because of performing his/her tasks in inappropriate way. It is generally recognised that the rail system without human element could never be happened quite long time. So human element in rail system is going to be the major factor to the next tragic accident. This state of the art report studied the cases of the managements and evaluation systems related to human errors, license requirements, and job aptitudes in the areas of rail and the other industries for the purpose of improvement of the task performance of personnel which consists of an element and finally enhancement of rail safety. The human errors, license requirements, and evaluation system of the job aptitude on people engaged in agencies with close relation to rail do much for development and preservation their abilities. But due to various inside and outside factors, to some extent it may have limitations to timely reflect overall trends of society, technology, and a sense of value. Removal and control of the factors of human errors will have epochal roles in safety of the rail system through the case studies of this report. Analytical results on case studies of this report will be used in the project 'Development of Management Criteria on Human Error and Evaluation Criteria on Job-aptitude of Rail Safe-operation Personnel' which has been carried out as a part of 'Integrated R and D Program for Railway Safety'.

  3. In vivo dosimetry: trends and prospects for brachytherapy

    DEFF Research Database (Denmark)

    Kertzscher, Gustavo; Rosenfeld, A.; Beddar, S.;

    2014-01-01

    ), it is established that real-time IVD can provide efficient error detection and treatment verification. However, it is also recognized that widespread implementations are hampered by the lack of available high-accuracy IVD systems that are straightforward for the clinical staff to use. This article......The error types during brachytherapy (BT) treatments and their occurrence rates are not well known. The limited knowledge is partly attributed to the lack of independent verification systems of the treatment progression in the clinical workflow routine. Within the field of in vivo dosimetry (IVD...

  4. Erectile function after prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To evaluate erectile function after permanent prostate brachytherapy using a validated patient-administered questionnaire and to determine the effect of multiple clinical, treatment, and dosimetric parameters on penile erectile function. Methods and materials: A total of 226 patients with preimplant erectile function determined by the International Index of Erectile Function (IIEF) questionnaire underwent permanent prostate brachytherapy in two prospective randomized trials between February 2001 and January 2003 for clinical Stage T1c-T2c (2002 American Joint Committee on Cancer) prostate cancer. Of the 226 patients, 132 were potent before treatment and, of those, 128 (97%) completed and returned the IIEF questionnaire after brachytherapy. The median follow-up was 29.1 months. Potency was defined as an IIEF score of ≥13. The clinical, treatment, and dosimetric parameters evaluated included patient age; preimplant IIEF score; clinical T stage; pretreatment prostate-specific antigen level; Gleason score; elapsed time after implantation; preimplant nocturnal erections; body mass index; presence of hypertension or diabetes mellitus; tobacco consumption; the volume of the prostate gland receiving 100%, 150%, and 200% of the prescribed dose (V100/150/200); the dose delivered to 90% of the prostate gland (D90); androgen deprivation therapy; supplemental external beam radiotherapy (EBRT); isotope; prostate volume; planning volume; and radiation dose to the proximal penis. Results: The 3-year actuarial rate of potency preservation was 50.5%. For patients who maintained adequate posttreatment erectile function, the preimplant IIEF score was 29, and in patients with brachytherapy-related ED, the preimplant IIEF score was 25. The median time to the onset of ED was 5.4 months. After brachytherapy, the median IIEF score was 20 in potent patients and 3 in impotent patients. On univariate analysis, the preimplant IIEF score, patient age, presence of nocturnal erections

  5. Abnormal error processing in depressive states: a translational examination in humans and rats

    Science.gov (United States)

    Beard, C; Donahue, R J; Dillon, D G; Van't Veer, A; Webber, C; Lee, J; Barrick, E; Hsu, K J; Foti, D; Carroll, F I; Carlezon Jr, W A; Björgvinsson, T; Pizzagalli, D A

    2015-01-01

    Depression has been associated with poor performance following errors, but the clinical implications, response to treatment and neurobiological mechanisms of this post-error behavioral adjustment abnormality remain unclear. To fill this gap in knowledge, we tested depressed patients in a partial hospital setting before and after treatment (cognitive behavior therapy combined with medication) using a flanker task. To evaluate the translational relevance of this metric in rodents, we performed a secondary analysis on existing data from rats tested in the 5-choice serial reaction time task after treatment with corticotropin-releasing factor (CRF), a stress peptide that produces depressive-like signs in rodent models relevant to depression. In addition, to examine the effect of treatment on post-error behavior in rodents, we examined a second cohort of rodents treated with JDTic, a kappa-opioid receptor antagonist that produces antidepressant-like effects in laboratory animals. In depressed patients, baseline post-error accuracy was lower than post-correct accuracy, and, as expected, post-error accuracy improved with treatment. Moreover, baseline post-error accuracy predicted attentional control and rumination (but not depressive symptoms) after treatment. In rats, CRF significantly degraded post-error accuracy, but not post-correct accuracy, and this effect was attenuated by JDTic. Our findings demonstrate deficits in post-error accuracy in depressed patients, as well as a rodent model relevant to depression. These deficits respond to intervention in both species. Although post-error behavior predicted treatment-related changes in attentional control and rumination, a relationship to depressive symptoms remains to be demonstrated. PMID:25966364

  6. Medication Errors

    Science.gov (United States)

    ... Proprietary Names (PDF - 146KB) Draft Guidance for Industry: Best Practices in Developing Proprietary Names for Drugs (PDF - 279KB) ... or (301) 796-3400 druginfo@fda.hhs.gov Human Drug ... in Medication Errors Resources for You Agency for Healthcare Research and Quality: ...

  7. Categorization framework of background factors Including organizational factors and its application to J-HPES. A study on applicability to human error incidents occurring at nuclear power plants

    International Nuclear Information System (INIS)

    CRIEPI has conducting detailed analyses of human error incidents occurring at nuclear power plants (NPPs) using J-HPES (Japanese version of HPES) as an analysis method. In order to support causal analysis of J-HPES, a categorization framework of background factors including organizational factors of human error incidents are identified. Each item of this framework (e.g. environment, individual work management) is defined and examples were extracted taking jobs at NPPs into consideration. The framework can be applied to J-HPES causal relation charts to show the extent of analysis. By applying this framework to human error incidents selected from U.S. Licensee Event Reports, it was suggested that the organizational factors of error incidents differs from the job types. Application of this framework to causal analysis of human error incidents would enable effective error management using safety-related information at individual plant. (author)

  8. Inverse planning in brachytherapy from radium to high rate 192 iridium afterloading

    International Nuclear Information System (INIS)

    We consider the inverse planning problem in brachytherapy, i.e. the problem to determine an optimal number of catheters, number of sources for low-dose rate brachytherapy (LDR) and the optimal dwell times for high-dose rate brachytherapy (HDR) necessary to obtain an optimal as possible dose distribution. Starting from the 1930s, inverse planning for LDR brachytherapy used geometrically derived rules to determine the optimal placement of sources in order to achieve a uniform dose distribution of a specific level in planes, spheres and cylinders. Rules and nomograms were derived which still are widely used. With the rapid development of 3D imaging technologies and the rapidly increasing computer power we have now entered the new era of computer-based inverse planning in brachytherapy. The inverse planning is now an optimisation process adapted to the individual geometry of the patient. New inverse planning optimisation algorithms are anatomy-based that consider the real anatomy of the tumour and the organs at risk (OAR). Computer-based inverse planning considers various effects such as stability of solutions for seed misplacements which cannot ever be solved analytically without gross simplifications. In the last few years multiobjective (MO) inverse planning algorithms have been developed which recognise the MO optimisation problem which is inherent in inverse planning in brachytherapy. Previous methods used a trial and error method to obtain a satisfactory solution. MO optimisation replaces this trial and error process by presenting a representative set of dose distributions that can be obtained. With MO optimisation it is possible to obtain information that can be used to obtain the optimum number of catheters, their position and the optimum distribution of dwell times for HDR brachytherapy. For LDR brachytherapy also the stability of solutions due to seed migration can also be improved. A spectrum of alternative solutions is available and the treatment planner

  9. Quantitative developments in the cognitive reliability and error analysis method (CREAM) for the assessment of human performance

    International Nuclear Information System (INIS)

    The current 'second generation' approaches in human reliability analysis focus their attention on the contextual conditions under which a given action is performed rather than on the notion of inherent human error probabilities, as was done in the earlier 'first generation' techniques. Among the 'second generation' methods, this paper considers the Cognitive Reliability and Error Analysis Method (CREAM) and proposes some developments with respect to a systematic procedure for computing probabilities of action failure. The starting point for the quantification is a previously introduced fuzzy version of the CREAM paradigm which is here further extended to include uncertainty on the qualification of the conditions under which the action is performed and to account for the fact that the effects of the common performance conditions (CPCs) on performance reliability may not all be equal. By the proposed approach, the probability of action failure is estimated by rating the performance conditions in terms of their effect on the action

  10. Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Part 2, Human Error Probability (HEP) estimates: Data manual

    International Nuclear Information System (INIS)

    This volume of a five-volume series summarizes those data currently resident in the first releases of the Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) data base. The raw human error probability (HEP) contained herein is accompanied by a glossary of terms and the HEP and hardware taxonomies used to structure the data. Instructions are presented on how the user may navigate through the NUCLARR data management system to find anchor values to assist in solving risk-related problems

  11. A statistical approach to estimating effects of performance shaping factors on human error probabilities of soft controls

    International Nuclear Information System (INIS)

    Despite recent efforts toward data collection for supporting human reliability analysis, there remains a lack of empirical basis in determining the effects of performance shaping factors (PSFs) on human error probabilities (HEPs). To enhance the empirical basis regarding the effects of the PSFs, a statistical methodology using a logistic regression and stepwise variable selection was proposed, and the effects of the PSF on HEPs related with the soft controls were estimated through the methodology. For this estimation, more than 600 human error opportunities related to soft controls in a computerized control room were obtained through laboratory experiments. From the eight PSF surrogates and combinations of these variables, the procedure quality, practice level, and the operation type were identified as significant factors for screen switch and mode conversion errors. The contributions of these significant factors to HEPs were also estimated in terms of a multiplicative form. The usefulness and limitation of the experimental data and the techniques employed are discussed herein, and we believe that the logistic regression and stepwise variable selection methods will provide a way to estimate the effects of PSFs on HEPs in an objective manner. - Highlights: • It is necessary to develop an empirical basis for the effects of the PSFs on the HEPs. • A statistical method using a logistic regression and variable selection was proposed. • The effects of PSFs on the HEPs of soft controls were empirically investigated. • The significant factors were identified and their effects were estimated

  12. Brachytherapy dosimeter with silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Moutinho, L.M., E-mail: moutinho@ua.pt [i3N, Physics Department, University of Aveiro (Portugal); Castro, I.F.C. [i3N, Physics Department, University of Aveiro (Portugal); Peralta, L. [Faculdade de Ciências da Universidade de Lisboa (Portugal); Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Lisboa (Portugal); Abreu, M.C. [Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Lisboa (Portugal); Veloso, J.F.C.A. [i3N, Physics Department, University of Aveiro (Portugal)

    2015-07-01

    In-vivo and in-situ measurement of the radiation dose administered during brachytherapy faces several technical challenges, requiring a very compact, tissue-equivalent, linear and highly sensitive dosimeter, particularly in low-dose rate brachytherapy procedures, which use radioactive seeds with low energy and low dose deposition rate. In this work we present a scintillating optical fiber dosimeter composed of a flexible sensitive probe and a dedicated electronic readout system based on silicon photomultiplier photodetection, capable of operating both in pulse and current modes. The performance of the scintillating fiber optic dosimeter was evaluated in low energy regimes, using an X-ray tube operating at voltages of 40–50 kV and currents below 1 mA, to assess minimum dose response of the scintillating fiber. The dosimeter shows a linear response with dose and is capable of detecting mGy dose variations like an ionization chamber. Besides fulfilling all the requirements for a dosimeter in brachytherapy, the high sensitivity of this device makes it a suitable candidate for application in low-dose rate brachytherapy. According to Peralta and Rego [1], the BCF-10 and BCF-60 scintillating optical fibers used in dosimetry exhibit high variations in their sensitivity for photon beams in the 25–100 kVp energy range. Energy linearity for energies below 50 keV needs to be further investigated, using monochromatic X-ray photons.

  13. Brachytherapy dosimeter with silicon photomultipliers

    Science.gov (United States)

    Moutinho, L. M.; Castro, I. F. C.; Peralta, L.; Abreu, M. C.; Veloso, J. F. C. A.

    2015-07-01

    In-vivo and in-situ measurement of the radiation dose administered during brachytherapy faces several technical challenges, requiring a very compact, tissue-equivalent, linear and highly sensitive dosimeter, particularly in low-dose rate brachytherapy procedures, which use radioactive seeds with low energy and low dose deposition rate. In this work we present a scintillating optical fiber dosimeter composed of a flexible sensitive probe and a dedicated electronic readout system based on silicon photomultiplier photodetection, capable of operating both in pulse and current modes. The performance of the scintillating fiber optic dosimeter was evaluated in low energy regimes, using an X-ray tube operating at voltages of 40-50 kV and currents below 1 mA, to assess minimum dose response of the scintillating fiber. The dosimeter shows a linear response with dose and is capable of detecting mGy dose variations like an ionization chamber. Besides fulfilling all the requirements for a dosimeter in brachytherapy, the high sensitivity of this device makes it a suitable candidate for application in low-dose rate brachytherapy. According to Peralta and Rego [1], the BCF-10 and BCF-60 scintillating optical fibers used in dosimetry exhibit high variations in their sensitivity for photon beams in the 25-100 kVp energy range. Energy linearity for energies below 50 keV needs to be further investigated, using monochromatic X-ray photons.

  14. In vivo dosimetry in brachytherapy

    DEFF Research Database (Denmark)

    Tanderup, Kari; Beddar, Sam; Andersen, Claus Erik; Kertzscher Schwencke, Gustavo Adolfo Vladimir; Cygler, Joanna E.

    2013-01-01

    In vivo dosimetry (IVD) has been used in brachytherapy (BT) for decades with a number of different detectors and measurement technologies. However, IVD in BT has been subject to certain difficulties and complexities, in particular due to challenges of the high-gradient BT dose distribution and the...

  15. Brachytherapy in coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Chun [Chonnam National University Medicine School, Gwangju (Korea, Republic of)

    2006-04-15

    Coronary artery disease is a leading cause of morbidity and mortality across the world. Percutaneous coronary intervention has become the major technique of revascularization. However, restenosis remains a major limitation of this procedure. Recently the need for repeat intervention due to restenosis, the most vexing long-term failure of percutaneous coronary intervention, has been significantly reduced owing to the introduction to two major advances, intracoronary brachytherapy and the drug-eluting stents, intracoronary brachytherapy has been employed in recent years to prevent restenosis lesions with effective results, principally in in-stent restenosis. Restenosis is generally considered as an excessive form of normal wound healing divided up in processes: elastic recoil, neointimal hyperplasia, and negative vascular remodeling. Restenosis has previously been regarded as a proliferative process in which neointimal thickening, mediated by a cascade of inflammatory mediators and other factors, is the key factor. Ionizing radiation has been shown to decrease the proliferative response to injury in animal models of restenosis. Subsequently, several randomized, double-blind trials have demonstrated that intracoronary brachytherapy can reduce the rates to both angiographic restenosis and clinical event rates in patients undergoing percutaneous coronary intervention for in-stent restenosis. Some problems, such as late thrombosis and edge restenosis, have been identified as limiting factors of this technique. Brachytherapy is a promising method of preventing and treating coronary artery restenosis.

  16. Dosimetry in intravascular brachytherapy

    International Nuclear Information System (INIS)

    Among the cardiovascular diseases responsible for deaths in the adult population in almost all countries of the world, the most common is acute myocardial infarction, which generally occurs because of the occlusion of one or more coronary arteries. Several diagnostic techniques and therapies are being tested for the treatment of coronary artery disease. Balloon angioplasty has been a popular treatment which is less invasive than traditional surgeries involving revascularization of the myocardium, thus promising a better quality of life for patients. Unfortunately, the rate of restenosis (re-closing of the vessel) after balloon angioplasty is high (approximately 30-50% within the first year after treatment).Recently, the idea of delivering high radiation doses to coronary arteries to avoid or delay restenosis has been suggested. Known as intravascular brachytherapy, the technique has been used with several radiation sources, and researchers have obtained success in decreasing the rate of restenosis in some patient populations. In order to study the radiation dosimetry in the patient and radiological protection for the attending staff for this therapy, radiation dose distributions for monoenergetic electrons and photons (at nine discrete energies) were calculated for blood vessels of diameter 0.15, o,30 and 0.45 cm with balloon and wire sources using the radiation transport code MCNP4B. Specific calculations were carried out for several candidate radionuclides as well. Two s tent sources (metallic prosthesis that put inside of patient's artery through angioplasty) employing 32 P are also simulated. Advantages and disadvantages of the various radionuclides and source geometries are discussed. The dosimetry developed here will aid in the realization of the benefits obtained in patients for this promising new technology. (author)

  17. Tomosynthesis-based localization of radioactive seeds in prostate brachytherapy

    International Nuclear Information System (INIS)

    Accurately assessing the quality of prostate brachytherapy intraoperatively would be valuable for improved clinical outcome by ensuring the delivery of a prescribed tumoricidal radiation dose to the entire prostate gland. One necessary step towards this goal is the robust and rapid localization of implanted seeds. Several methods have been developed to locate seeds from x-ray projection images, but they fail to detect completely-overlapping seeds, thus necessitating manual intervention. To overcome this limitation, we have developed a new method where (1) a three-dimensional volume is reconstructed from x-ray projection images using a brachytherapy-specific tomosynthesis reconstruction algorithm with built-in blur compensation and (2) the seeds are located in this reconstructed volume. In contrast to other projection-based methods, our method can detect completely overlapping seeds. Our simulation results indicate that we can locate all implanted seeds in the prostate using a tomosynthesis angle of 30 deg. and seven projection images. The mean localization error is 1.27 mm for a case with 100 seeds. We have also tested our method using a prostate phantom with 61 implanted seeds and succeeded in locating all seeds automatically. We believe this new method can be useful for the intraoperative quality assessment of prostate brachytherapy in the future

  18. ATHEANA: {open_quotes}a technique for human error analysis{close_quotes} entering the implementation phase

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, J.; O`Hara, J.; Luckas, W. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1997-02-01

    Probabilistic Risk Assessment (PRA) has become an increasingly important tool in the nuclear power industry, both for the Nuclear Regulatory Commission (NRC) and the operating utilities. The NRC recently published a final policy statement, SECY-95-126, encouraging the use of PRA in regulatory activities. Human reliability analysis (HRA), while a critical element of PRA, has limitations in the analysis of human actions in PRAs that have long been recognized as a constraint when using PRA. In fact, better integration of HRA into the PRA process has long been a NRC issue. Of particular concern, has been the omission of errors of commission - those errors that are associated with inappropriate interventions by operators with operating systems. To address these concerns, the NRC identified the need to develop an improved HRA method, so that human reliability can be better represented and integrated into PRA modeling and quantification. The purpose of the Brookhaven National Laboratory (BNL) project, entitled `Improved HRA Method Based on Operating Experience` is to develop a new method for HRA which is supported by the analysis of risk-significant operating experience. This approach will allow a more realistic assessment and representation of the human contribution to plant risk, and thereby increase the utility of PRA. The project`s completed, ongoing, and future efforts fall into four phases: (1) Assessment phase (FY 92/93); (2) Analysis and Characterization phase (FY 93/94); (3) Development phase (FY 95/96); and (4) Implementation phase (FY 96/97 ongoing).

  19. Inborn errors of mucocutaneous immunity to Candida albicans in humans: a role for IL-17 cytokines?

    OpenAIRE

    Puel, Anne; Picard, Capucine; Cypowyj, Sophie; Lilic, Desa; Abel, Laurent; Casanova, Jean-Laurent

    2010-01-01

    The various clinical manifestations of chronic mucocutaneous candidiasis (CMC) often result from acquired T-cell immunodeficiencies. More rarely, CMC results from inborn errors of immunity, the recent dissection of which has shed light on the molecular mechanisms of mucocutaneous immunity to Candida albicans. CMC may accompany various other infectious diseases in patients with almost any broad and profound T-cell primary immunodeficiency. By contrast, CMC is one of the few key infections in p...

  20. Analysis of Task Types and Error Types of the Human Actions Involved in the Human-related Unplanned Reactor Trip Events

    International Nuclear Information System (INIS)

    This report provides the task types and error types involved in the unplanned reactor trip events that have occurred during 1986 - 2006. The events that were caused by the secondary system of the nuclear power plants amount to 67 %, and the remaining 33 % was by the primary system. The contribution of the activities of the plant personnel was identified as the following order: corrective maintenance (25.7 %), planned maintenance (22.8 %), planned operation (19.8 %), periodic preventive maintenance (14.9 %), response to a transient (9.9 %), and design/manufacturing/installation (9.9%). According to the analysis of error modes, the error modes such as control failure (22.2 %), wrong object (18.5 %), omission (14.8 %), wrong action (11.1 %), and inadequate (8.3 %) take up about 75 % of all the unplanned trip events. The analysis of the cognitive functions involved showed that the planning function makes the highest contribution to the human actions leading to unplanned reactor trips, and it is followed by the observation function (23.4%), the execution function (17.8 %), and the interpretation function (10.3 %). The results of this report are to be used as important bases for development of the error reduction measures or development of the error mode prediction system for the test and maintenance tasks in nuclear power plants

  1. A quality management program in intravascular brachytherapy.

    Science.gov (United States)

    Chakri, Abderrahim; Thomadsen, Bruce

    2002-12-01

    While simple, intravascular brachytherapy (IVB) presents a considerable potential for harm to the patient. The medical physicist maintains the responsibility to minimize the likelihood of operational problems or dosimetric errors. The principals for safe operation remain the same as with any radiotherapy treatment: to deliver the correct dose, to the correct location, safety. To develop an effective and comprehensive quality management (QM) program for IVB, a physicist should utilize proven risk assessment techniques rather than simply thinking of things to check, and follow guidances such as ISO9001:2000. The proposed QM program includes the following: Procedures designed to assure the safety of the patient. Identification of the patient; tests of the integrity and patency for the delivery catheter, operation of the source train, and patency of the catheter in the treatment position; a check for recovery preparations; and verification of source recovery. Procedures to assure positional accuracy of the treatment: Verification of the positioning the catheter in the artery and of the sources in the catheter. Procedures to assure dosimetry accuracy: Acceptance testing of the device, including verification of the source strength and uniformity, and of the treatment duration tables; verification of the treatment prescription and duration for each patient; and control measures that minimize the likelihood of errors removing the source at the correct time. PMID:12512720

  2. The Human Rights Act in the shadow of the European Convention: are copyist's errors allowed?

    OpenAIRE

    C. Draghici

    2014-01-01

    This article challenges the dichotomy often proposed by the scholarship and jurisprudence between the rights guaranteed in the European Convention on Human Rights and those claimants can rely on under the Human Rights Act 1998. It discussesthe two contentionsinforming this approach, namely the autonomy of meaning of the Human Rights Act“Convention Rights”and the authority of domestic courtsto interpret the Convention provisions.The authorrelies on the effects of incorporation of treaty normsi...

  3. Brachytherapy: Physical and clinical aspects

    International Nuclear Information System (INIS)

    Brachytherapy is a term used to describe the short distance treatment of cancer with radiation from small, encapsulated radionuclide sources. This type of treatment is given by placing sources directly into or near the volume to be treated. The dose is then delivered continuously, either over a short period of time (temporary implants) or over the lifetime of the source to a complete decay (permanent implants). Most common brachytherapy sources emit photons; however, in a few specialized situations b or neutron emitting sources are used. There are two main types of brachytherapy treatment: 1) Intracavitary, in which the sources are placed in body cavities close to the tumour volume; 2) Interstitial, in which the sources are implanted within the tumour volume. Intracavitary treatments are always temporary, of short duration, while interstitial treatments may be temporary or permanent. Temporary implants are inserted using either manual or remote afterloading procedures. Other, less common forms of brachytherapy treatments include surface plaque, intraluminal, intraoperative and intravascular source applications; for these treatments either g or b emitting sources are used. The physical advantage of brachytherapy treatments compared with external beam radiotherapy is the improved localized delivery of dose to the target volume of interest. The disadvantage is that brachytherapy can only be used in cases in which the tumour is well localized and relatively small. In a typical radiotherapy department about 10-20% of all radiotherapy patients are treated with brachytherapy. Several aspects must be considered when giving brachytherapy treatments. Of importance is the way in which the sources are positioned relative to the volume to be treated, and several different models have been developed over the past decades for this purpose. The advantage of using a well established model is that one benefits from the long experience associated with such models and that one can

  4. Addressing Uncorrected Refractive Error Through Human Resource Development in the Context of Mozambique

    OpenAIRE

    Thompson, Stephen; Loughman, James; Ramson, Prasidh; Bilotto, Luigi; Naidoo, Kovin

    2012-01-01

    This paper presents results from a national situational analysis. An International Agency for Prevention of Blindness (IAPB) tool was used to map current eye care services recorded including human resource and equipment. Data was analysed against VISION 2020 Human Resource targets.

  5. Accurate human microsatellite genotypes from high-throughput resequencing data using informed error profiles.

    Science.gov (United States)

    Highnam, Gareth; Franck, Christopher; Martin, Andy; Stephens, Calvin; Puthige, Ashwin; Mittelman, David

    2013-01-01

    Repetitive sequences are biologically and clinically important because they can influence traits and disease, but repeats are challenging to analyse using short-read sequencing technology. We present a tool for genotyping microsatellite repeats called RepeatSeq, which uses Bayesian model selection guided by an empirically derived error model that incorporates sequence and read properties. Next, we apply RepeatSeq to high-coverage genomes from the 1000 Genomes Project to evaluate performance and accuracy. The software uses common formats, such as VCF, for compatibility with existing genome analysis pipelines. Source code and binaries are available at http://github.com/adaptivegenome/repeatseq. PMID:23090981

  6. Automated Digital Image Analysis (TrichoScan®) for Human Hair Growth Analysis: Ease versus Errors

    OpenAIRE

    Saraogi, Punit P; Rachita S Dhurat

    2010-01-01

    Background: TrichoScan® is considered to be time-saving, easy to perform and consistent for quantifying hair loss/growth. Conflicting results of our study lead us to closely observe the image analysis, and certain repeated errors in the detection of hair were highlighted. Aims: To assess the utility of TrichoScan in quantification of diffuse hair loss in males with androgenetic alopecia (AGA) and females with diffuse telogen hair loss, with regard to total hair density (THD), telogen and vell...

  7. Rectal function following prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Quality of life following therapeutic intervention for carcinoma of the prostate gland has not been well documented. In particular, a paucity of data has been published regarding bowel function following prostate brachytherapy. This study evaluated late bowel function in 209 consecutive prostate brachytherapy patients via a one-time questionnaire administered 16-55 months postimplant. Materials and Methods: Two hundred nineteen consecutive patients underwent permanent prostate brachytherapy from April 1995 through February 1998 using either 125I or 103Pd for clinical T1c-T3a carcinoma of the prostate gland. Of the 219 patients, 7 had expired. Of the remaining 212 patients (median follow-up, 28 months), each patient was mailed a self-administered questionnaire (10 questions) with a prestamped return envelope; 209 (98.6%) surveys were returned. Clinical parameters evaluated for bowel dysfunction included patient age, diabetes, hypertension, history of tobacco consumption, clinical T-stage, elapsed time since implant, and prostate ultrasound volume. Treatment parameters included utilization of neoadjuvant hormonal manipulation, utilization of moderate dose external beam radiation therapy prior to implantation, choice of isotope (125I vs. 103Pd), rectal dose (average, median and maximum doses), total implanted seed strength, values of the minimum dose received by 90% of the prostate gland (D90), and the percent prostate volume receiving 100%, 150%, and 200% of the prescribed minimum peripheral dose (V100, V150 and V200, respectively). Because detailed baseline bowel function was not available for these patients, a cross-sectional survey was performed in which 30 newly diagnosed prostate cancer patients of comparable demographics served as controls. Results: The total rectal function scores for the brachytherapy and control patients were 4.3 and 1.6, respectively, out of a total 27 points (p 103Pd resulted in lower radiation doses to the rectum, the choice of

  8. Adaptive prediction of human eye pupil position and effects on wavefront errors

    Science.gov (United States)

    Garcia-Rissmann, Aurea; Kulcsár, Caroline; Raynaud, Henri-François; El Mrabet, Yamina; Sahin, Betul; Lamory, Barbara

    2011-03-01

    The effects of pupil motion on retinal imaging are studied in this paper. Involuntary eye or head movements are always present in the imaging procedure, decreasing the output quality and preventing a more detailed diagnostics. When the image acquisition is performed using an adaptive optics (AO) system, substantial gain is foreseen if pupil motion is accounted for. This can be achieved using a pupil tracker as the one developed by Imagine Eyes R®, which provides pupil position measurements at a 80Hz sampling rate. In any AO loop, there is inevitably a delay between the wavefront measurement and the correction applied to the deformable mirror, meaning that an optimal compensation requires prediction. We investigate several ways of predicting pupil movement, either by retaining the last value given by the pupil tracker, which is close to the optimal solution in the case of a pure random walk, or by performing position prediction thanks to auto-regressive (AR) models with parameters updated in real time. We show that a small improvement in prediction with respect to predicting with the latest measured value is obtained through adaptive AR modeling. We evaluate the wavefront errors obtained by computing the root mean square of the difference between a wavefront displaced by the assumed true position and the predicted one, as seen by the imaging system. The results confirm that pupil movements have to be compensated in order to minimize wavefront errors.

  9. The Measure of Human Error: Direct and Indirect Performance Shaping Factors

    Energy Technology Data Exchange (ETDEWEB)

    Ronald L. Boring; Candice D. Griffith; Jeffrey C. Joe

    2007-08-01

    The goal of performance shaping factors (PSFs) is to provide measures to account for human performance. PSFs fall into two categories—direct and indirect measures of human performance. While some PSFs such as “time to complete a task” are directly measurable, other PSFs, such as “fitness for duty,” can only be measured indirectly through other measures and PSFs, such as through fatigue measures. This paper explores the role of direct and indirect measures in human reliability analysis (HRA) and the implications that measurement theory has on analyses and applications using PSFs. The paper concludes with suggestions for maximizing the reliability and validity of PSFs.

  10. Electrophysiological correlates of self-specific prediction errors in the human brain.

    Science.gov (United States)

    Sel, Alejandra; Harding, Rachel; Tsakiris, Manos

    2016-01-15

    Recognising one's self, vs. others, is a key component of self-awareness, crucial for social interactions. Here we investigated whether processing self-face and self-body images can be explained by the brain's prediction of sensory events, based on regularities in the given context. We measured evoked cortical responses while participants observed alternating sequences of self-face or other-face images (experiment 1) and self-body or other-body images (experiment 2), which were embedded in an identity-irrelevant task. In experiment 1, the expected sequences were violated by deviant morphed images, which contained 33%, 66% or 100% of the self-face when the other's face was expected (and vice versa). In experiment 2, the anticipated sequences were violated by deviant images of the self when the other's image was expected (and vice versa), or by two deviant images composed of pictures of the self-face attached to the other's body, or the other's face attached to the self-body. This manipulation allowed control of the prediction error associated with the self or the other's image. Deviant self-images (but not deviant images of the other) elicited a visual mismatch response (vMMR)--a cortical index of violations of regularity. This was source localised to face and body related visual, sensorimotor and limbic areas and had amplitude proportional to the amount of deviance from the self-image. We provide novel evidence that self-processing can be described by the brain's prediction error system, which accounts for self-bias in visual processing. These findings are discussed in the light of recent predictive coding models of self-processing. PMID:26455899

  11. Physical aspects of radioisotope brachytherapy

    International Nuclear Information System (INIS)

    The present report represents an attempt to provide, within a necessarily limited compass, an authoritative guide to all important physical aspects of the use of sealed gamma sources in radiotherapy. Within the report, reference is made wherever necessary to the more extensive but scattered literature on this subject. While this report attempts to cover all the physical aspects of radioisotope 'brachytherapy' it does not, of course, deal exhaustively with any one part of the subject. 384 refs, 3 figs, 6 tabs

  12. Afterloading: The Technique That Rescued Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Aronowitz, Jesse N., E-mail: jesse.aronowitz@umassmemorial.org

    2015-07-01

    Although brachytherapy had been established as a highly effective modality for the treatment of cancer, its application was threatened by mid-20th century due to appreciation of the radiation hazard to health care workers. This review examines how the introduction of afterloading eliminated exposure and ushered in a brachytherapy renaissance.

  13. Interstitial prostate brachytherapy. LDR-PDR-HDR

    International Nuclear Information System (INIS)

    The first comprehensive overview of interstitial brachytherapy for the management of local or locally advanced prostate cancer. Written by an interdisciplinary team who have been responsible for the successful GEC-ESTRO/EAU Teaching Course. Discusses in detail patient selection, the results of different methods, the role of imaging, and medical physics issues. Prostate brachytherapy has been the subject of heated debate among surgeons and the proponents of the various brachytherapy methods. This very first interdisciplinary book on the subject provides a comprehensive overview of innovations in low dose rate (LDR), high dose rate (HDR), and pulsed dose rate (PDR) interstitial brachytherapy for the management of local or locally advanced prostate cancer. In addition to detailed chapters on patient selection and the use of imaging in diagnostics, treatment guidance, and implantation control, background chapters are included on related medical physics issues such as treatment planning and quality assurance. The results obtained with the different treatment options and the difficult task of salvage treatment are fully discussed. All chapters have been written by internationally recognized experts in their fields who for more than a decade have formed the teaching staff responsible for the successful GEC-ESTRO/EAU Prostate Brachytherapy Teaching Course. This book will be invaluable in informing residents and others of the scientific background and potential of modern prostate brachytherapy. It will also prove a useful source of up-to-date information for those who specialize in prostate brachytherapy or intend to start an interstitial brachytherapy service.

  14. Estimation of human error probabilities of a PWR plant APS level 1 by EPRI methodology

    International Nuclear Information System (INIS)

    This thesis presents the application of a human reliability analysis methodology developed by the Electric Power Research Institute (EPRI), which is based on operator reliability experiments. The EPRI methodology is applied to some predefined events in order to check its applicability and effectiveness. The results presented concerning the events where the available data allowed the application of EPRI methodology are quantitative. Conclusions and recommendations are presented based on the methodology and systematic here discussed in relation to the data, methodologies and systematics used in the analysis of human reliability for the probabilistic safety assessment of the Angra 1 nuclear power plant. (author)

  15. Dynamic rotating-shield brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To present dynamic rotating shield brachytherapy (D-RSBT), a novel form of high-dose-rate brachytherapy (HDR-BT) with electronic brachytherapy source, where the radiation shield is capable of changing emission angles during the radiation delivery process.Methods: A D-RSBT system uses two layers of independently rotating tungsten alloy shields, each with a 180° azimuthal emission angle. The D-RSBT planning is separated into two stages: anchor plan optimization and optimal sequencing. In the anchor plan optimization, anchor plans are generated by maximizing the D90 for the high-risk clinical-tumor-volume (HR-CTV) assuming a fixed azimuthal emission angle of 11.25°. In the optimal sequencing, treatment plans that most closely approximate the anchor plans under the delivery-time constraint will be efficiently computed. Treatment plans for five cervical cancer patients were generated for D-RSBT, single-shield RSBT (S-RSBT), and 192Ir-based intracavitary brachytherapy with supplementary interstitial brachytherapy (IS + ICBT) assuming five treatment fractions. External beam radiotherapy doses of 45 Gy in 25 fractions of 1.8 Gy each were accounted for. The high-risk clinical target volume (HR-CTV) doses were escalated such that the D2cc of the rectum, sigmoid colon, or bladder reached its tolerance equivalent dose in 2 Gy fractions (EQD2 with α/β= 3 Gy) of 75 Gy, 75 Gy, or 90 Gy, respectively.Results: For the patients considered, IS + ICBT had an average total dwell time of 5.7 minutes/fraction (min/fx) assuming a 10 Ci192Ir source, and the average HR-CTV D90 was 78.9 Gy. In order to match the HR-CTV D90 of IS + ICBT, D-RSBT required an average of 10.1 min/fx more delivery time, and S-RSBT required 6.7 min/fx more. If an additional 20 min/fx of delivery time is allowed beyond that of the IS + ICBT case, D-RSBT and S-RSBT increased the HR-CTV D90 above IS + ICBT by an average of 16.3 Gy and 9.1 Gy, respectively.Conclusions: For cervical cancer patients, D

  16. Dynamic rotating-shield brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yunlong [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 (United States); Flynn, Ryan T.; Kim, Yusung [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Yang, Wenjun [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Wu, Xiaodong [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 and Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States)

    2013-12-15

    Purpose: To present dynamic rotating shield brachytherapy (D-RSBT), a novel form of high-dose-rate brachytherapy (HDR-BT) with electronic brachytherapy source, where the radiation shield is capable of changing emission angles during the radiation delivery process.Methods: A D-RSBT system uses two layers of independently rotating tungsten alloy shields, each with a 180° azimuthal emission angle. The D-RSBT planning is separated into two stages: anchor plan optimization and optimal sequencing. In the anchor plan optimization, anchor plans are generated by maximizing the D{sub 90} for the high-risk clinical-tumor-volume (HR-CTV) assuming a fixed azimuthal emission angle of 11.25°. In the optimal sequencing, treatment plans that most closely approximate the anchor plans under the delivery-time constraint will be efficiently computed. Treatment plans for five cervical cancer patients were generated for D-RSBT, single-shield RSBT (S-RSBT), and {sup 192}Ir-based intracavitary brachytherapy with supplementary interstitial brachytherapy (IS + ICBT) assuming five treatment fractions. External beam radiotherapy doses of 45 Gy in 25 fractions of 1.8 Gy each were accounted for. The high-risk clinical target volume (HR-CTV) doses were escalated such that the D{sub 2cc} of the rectum, sigmoid colon, or bladder reached its tolerance equivalent dose in 2 Gy fractions (EQD2 with α/β= 3 Gy) of 75 Gy, 75 Gy, or 90 Gy, respectively.Results: For the patients considered, IS + ICBT had an average total dwell time of 5.7 minutes/fraction (min/fx) assuming a 10 Ci{sup 192}Ir source, and the average HR-CTV D{sub 90} was 78.9 Gy. In order to match the HR-CTV D{sub 90} of IS + ICBT, D-RSBT required an average of 10.1 min/fx more delivery time, and S-RSBT required 6.7 min/fx more. If an additional 20 min/fx of delivery time is allowed beyond that of the IS + ICBT case, D-RSBT and S-RSBT increased the HR-CTV D{sub 90} above IS + ICBT by an average of 16.3 Gy and 9.1 Gy, respectively

  17. The neural correlates of negative prediction error signaling in human fear conditioning.

    Science.gov (United States)

    Spoormaker, V I; Andrade, K C; Schröter, M S; Sturm, A; Goya-Maldonado, R; Sämann, P G; Czisch, M

    2011-02-01

    In a temporal difference (TD) learning approach to classical conditioning, a prediction error (PE) signal shifts from outcome deliverance to the onset of the conditioned stimulus. Omission of an expected outcome results in a negative PE signal, which is the initial step towards successful extinction. In order to visualize negative PE signaling during fear conditioning, we employed combined functional magnetic resonance (fMRI) and skin conductance response (SCR) measurements in a conditioning task with visual stimuli and mild electrical shocks. Positive PE signaling was associated with increased activation in the bilateral insula, supplementary motor area, brainstem, and visual cortices. Negative PE signaling was associated with increased activation in the ventromedial and dorsolateral prefrontal cortices, the left lateral orbital gyrus, the middle temporal gyri, angular gyri, and visual cortices. The involvement of the ventromedial prefrontal and orbitofrontal cortex in extinction learning has been well documented, and this study provides evidence for the notion that these regions are already involved in negative PE signaling during fear conditioning. PMID:20869454

  18. Theoretical effect of refractive error and accommodation on longitudinal chromatic aberration of the human eye.

    Science.gov (United States)

    Atchison, D A; Smith, G; Waterworth, M D

    1993-09-01

    Simple formulas based on reduced eyes have been developed to predict the variation in longitudinal chromatic aberration with variation in ametropia or accommodation. Two formulas were developed, one for axial ametropia and one for refractive ametropia. The latter also served as a model for accommodation. The results using the formulas are in close agreement with results obtained using raytracing through more sophisticated models. Combining the results of different methods gives the following predictions of change in chromatic difference of focus, between wavelengths of 400 and 700 nm, with change in each diopter of refractive error or accommodation: axial ametropia 0.012 to 0.017 D (0.6 to 0.9%), refractive ametropia 0.05 D (2.2 to 2.4%), and accommodation 0.04 to 0.05 D (2.1 to 2.6%). The chromatic aberration effects of correcting lenses with low dispersion are intermediate in effect and opposite in sign to the effects of corresponding degrees of axial ametropia and refractive ametropia. PMID:8233365

  19. Dosimetry Modeling for Focal Low-Dose-Rate Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Al-Qaisieh, Bashar [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Mason, Josh, E-mail: joshua.mason@nhs.net [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Bownes, Peter; Henry, Ann [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Dickinson, Louise [Division of Surgery and Interventional Science, University College London, London (United Kingdom); Department of Radiology, Northwick Park Hospital, London North West NHS Trust, London (United Kingdom); Ahmed, Hashim U. [Division of Surgery and Interventional Science, University College London, London (United Kingdom); University College London Hospital, London (United Kingdom); Emberton, Mark [University College London Hospital, London (United Kingdom); Langley, Stephen [St Luke' s Cancer Centre, Guildford (United Kingdom)

    2015-07-15

    Purpose: Focal brachytherapy targeted to an individual lesion(s) within the prostate may reduce side effects experienced with whole-gland brachytherapy. The outcomes of a consensus meeting on focal prostate brachytherapy were used to investigate optimal dosimetry of focal low-dose-rate (LDR) prostate brachytherapy targeted using multiparametric magnetic resonance imaging (mp-MRI) and transperineal template prostate mapping (TPM) biopsy, including the effects of random and systematic seed displacements and interseed attenuation (ISA). Methods and Materials: Nine patients were selected according to clinical characteristics and concordance of TPM and mp-MRI. Retrospectively, 3 treatment plans were analyzed for each case: whole-gland (WG), hemi-gland (hemi), and ultra-focal (UF) plans, with 145-Gy prescription dose and identical dose constraints for each plan. Plan robustness to seed displacement and ISA were assessed using Monte Carlo simulations. Results: WG plans used a mean 28 needles and 81 seeds, hemi plans used 17 needles and 56 seeds, and UF plans used 12 needles and 25 seeds. Mean D90 (minimum dose received by 90% of the target) and V100 (percentage of the target that receives 100% dose) values were 181.3 Gy and 99.8% for the prostate in WG plans, 195.7 Gy and 97.8% for the hemi-prostate in hemi plans, and 218.3 Gy and 99.8% for the focal target in UF plans. Mean urethra D10 was 205.9 Gy, 191.4 Gy, and 92.4 Gy in WG, hemi, and UF plans, respectively. Mean rectum D2 cm{sup 3} was 107.5 Gy, 77.0 Gy, and 42.7 Gy in WG, hemi, and UF plans, respectively. Focal plans were more sensitive to seed displacement errors: random shifts with a standard deviation of 4 mm reduced mean target D90 by 14.0%, 20.5%, and 32.0% for WG, hemi, and UF plans, respectively. ISA has a similar impact on dose-volume histogram parameters for all plan types. Conclusions: Treatment planning for focal LDR brachytherapy is feasible. Dose constraints are easily met with a notable

  20. Dosimetry Modeling for Focal Low-Dose-Rate Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Focal brachytherapy targeted to an individual lesion(s) within the prostate may reduce side effects experienced with whole-gland brachytherapy. The outcomes of a consensus meeting on focal prostate brachytherapy were used to investigate optimal dosimetry of focal low-dose-rate (LDR) prostate brachytherapy targeted using multiparametric magnetic resonance imaging (mp-MRI) and transperineal template prostate mapping (TPM) biopsy, including the effects of random and systematic seed displacements and interseed attenuation (ISA). Methods and Materials: Nine patients were selected according to clinical characteristics and concordance of TPM and mp-MRI. Retrospectively, 3 treatment plans were analyzed for each case: whole-gland (WG), hemi-gland (hemi), and ultra-focal (UF) plans, with 145-Gy prescription dose and identical dose constraints for each plan. Plan robustness to seed displacement and ISA were assessed using Monte Carlo simulations. Results: WG plans used a mean 28 needles and 81 seeds, hemi plans used 17 needles and 56 seeds, and UF plans used 12 needles and 25 seeds. Mean D90 (minimum dose received by 90% of the target) and V100 (percentage of the target that receives 100% dose) values were 181.3 Gy and 99.8% for the prostate in WG plans, 195.7 Gy and 97.8% for the hemi-prostate in hemi plans, and 218.3 Gy and 99.8% for the focal target in UF plans. Mean urethra D10 was 205.9 Gy, 191.4 Gy, and 92.4 Gy in WG, hemi, and UF plans, respectively. Mean rectum D2 cm3 was 107.5 Gy, 77.0 Gy, and 42.7 Gy in WG, hemi, and UF plans, respectively. Focal plans were more sensitive to seed displacement errors: random shifts with a standard deviation of 4 mm reduced mean target D90 by 14.0%, 20.5%, and 32.0% for WG, hemi, and UF plans, respectively. ISA has a similar impact on dose-volume histogram parameters for all plan types. Conclusions: Treatment planning for focal LDR brachytherapy is feasible. Dose constraints are easily met with a notable reduction

  1. High dose rate brachytherapy for oral cancer

    International Nuclear Information System (INIS)

    Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer. (author)

  2. From human errors to drivers' needs: An evaluation of the potential effectiveness of safety functions

    OpenAIRE

    VAN ELSLANDE, Pierre

    2011-01-01

    A specific contribution to evaluation of safety functions efficiency directed toward road user's needs, a methodology taking into account human difficulties (functional failures) and accident reality (context parameters), allow defining: Safety needs for different kinds of drivers, reflecting their accident-generating failures at the different stage of the process ; The potential capacity of safety functions to meet these needs ; The potential lacks in the functions efficiency ; The condition...

  3. What Happened, and Why: Toward an Understanding of Human Error Based on Automated Analyses of Incident Reports. Volume 1

    Science.gov (United States)

    Maille, Nicolas P.; Statler, Irving C.; Ferryman, Thomas A.; Rosenthal, Loren; Shafto, Michael G.; Statler, Irving C.

    2006-01-01

    The objective of the Aviation System Monitoring and Modeling (ASMM) project of NASA s Aviation Safety and Security Program was to develop technologies that will enable proactive management of safety risk, which entails identifying the precursor events and conditions that foreshadow most accidents. This presents a particular challenge in the aviation system where people are key components and human error is frequently cited as a major contributing factor or cause of incidents and accidents. In the aviation "world", information about what happened can be extracted from quantitative data sources, but the experiential account of the incident reporter is the best available source of information about why an incident happened. This report describes a conceptual model and an approach to automated analyses of textual data sources for the subjective perspective of the reporter of the incident to aid in understanding why an incident occurred. It explores a first-generation process for routinely searching large databases of textual reports of aviation incident or accidents, and reliably analyzing them for causal factors of human behavior (the why of an incident). We have defined a generic structure of information that is postulated to be a sound basis for defining similarities between aviation incidents. Based on this structure, we have introduced the simplifying structure, which we call the Scenario as a pragmatic guide for identifying similarities of what happened based on the objective parameters that define the Context and the Outcome of a Scenario. We believe that it will be possible to design an automated analysis process guided by the structure of the Scenario that will aid aviation-safety experts to understand the systemic issues that are conducive to human error.

  4. The action characterization matrix: A link between HERA (Human Events Reference for ATHEANA) and ATHEANA (a technique for human error analysis)

    International Nuclear Information System (INIS)

    The Technique for Human Error Analysis (ATHEANA) is a newly developed human reliability analysis (HRA) methodology that aims to facilitate better representation and integration of human performance into probabilistic risk assessment (PRA) modeling and quantification by analyzing risk-significant operating experience in the context of existing behavior science models. The fundamental premise of ATHEANA is that error-forcing contexts (EFCs), which refer to combinations of equipment/material conditions and performance shaping factors (PSFs), set up or create the conditions under which unsafe actions (UAs) can occur. ATHEANA is being developed in the context of nuclear power plant (NPP) PRAs, and much of the language used to describe the method and provide examples of its application are specific to that industry. Because ATHEANA relies heavily on the analysis of operational events that have already occurred as a mechanism for generating creative thinking about possible EFCs, a database, called the Human Events Reference for ATHEANA (HERA), has been developed to support the methodology. Los Alamos National Laboratory's (LANL) Human Factors Group has recently joined the ATHEANA project team; LANL is responsible for further developing the database structure and for analyzing additional exemplar operational events for entry into the database. The Action Characterization Matrix (ACM) is conceived as a bridge between the HERA database structure and ATHEANA. Specifically, the ACM allows each unsafe action or human failure event to be characterized according to its representation along each of six different dimensions: system status, initiator status, unsafe action mechanism, information processing stage, equipment/material conditions, and performance shaping factors. This report describes the development of the ACM and provides details on the structure and content of its dimensions

  5. Collection and preparation of data bank for incident and failure reports and analysis of human error related incidents

    International Nuclear Information System (INIS)

    Nuclear Power Safety Information Research Center (NUSIRC) of the Nuclear Power Engineering Test Center (NUPEC) has been established in 1984 to manage and utilize these materials relating to the incident/failure reports as the data bank, in which the information is classified by some 1,600 keywords and input to the computer data bank system. Incident/failure classification, statistical work on the database and utilization of data are being conducted based on this data bank. This paper briefly describes general outline of the data bank and statistical analytical results of incidents/failures due to human error with practical examples and further mentions on the information transmittal and exchange, effective methods for preventing reccurrence. (EG)

  6. Development of regulatory requirements for evaluating the aptitude and the human error of safety-related personnel

    International Nuclear Information System (INIS)

    Railroad system is composed of railroad line facility, rolling stock, operation, control and maintenance of the train. It is superior to other transportation systems in safety and swiftness. But the accident can occur by a small neglect. Among these accidents, the accidents due to human error of the safety-related employee take the large portion of them. In order to prevent the railroad accidents and to improve the job-safety of safety-related employees, it is necessary to setup the evaluation criteria for the physical test and aptitude test of the safety-related employees. This project intends to develop the implementation guideline for the job-aptitude test of the safety-related employee in the railroad industry

  7. Procedures for using expert judgment to estimate human-error probabilities in nuclear power plant operations. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Seaver, D.A.; Stillwell, W.G.

    1983-03-01

    This report describes and evaluates several procedures for using expert judgment to estimate human-error probabilities (HEPs) in nuclear power plant operations. These HEPs are currently needed for several purposes, particularly for probabilistic risk assessments. Data do not exist for estimating these HEPs, so expert judgment can provide these estimates in a timely manner. Five judgmental procedures are described here: paired comparisons, ranking and rating, direct numerical estimation, indirect numerical estimation and multiattribute utility measurement. These procedures are evaluated in terms of several criteria: quality of judgments, difficulty of data collection, empirical support, acceptability, theoretical justification, and data processing. Situational constraints such as the number of experts available, the number of HEPs to be estimated, the time available, the location of the experts, and the resources available are discussed in regard to their implications for selecting a procedure for use.

  8. Development of regulatory requirements for evaluating the aptitude and the human error of safety-related personnel

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Tack Hyun; Kook, Kwang Ho; Han, Sang Wook [SNUT, Seoul (Korea, Republic of)

    2008-03-15

    Railroad system is composed of railroad line facility, rolling stock, operation, control and maintenance of the train. It is superior to other transportation systems in safety and swiftness. But the accident can occur by a small neglect. Among these accidents, the accidents due to human error of the safety-related employee take the large portion of them. In order to prevent the railroad accidents and to improve the job-safety of safety-related employees, it is necessary to setup the evaluation criteria for the physical test and aptitude test of the safety-related employees. This project intends to develop the implementation guideline for the job-aptitude test of the safety-related employee in the railroad industry.

  9. The use of TLDs for brachytherapy dosimetry

    International Nuclear Information System (INIS)

    Thermoluminescent dosimeters (TLDs) are routinely used to measure the dose around brachytherapy sources due to their small size and high precision. This work presents a concise overview of the use of LiF:Mg,Ti TLDs for brachytherapy dosimetry including the experimental procedures required to achieve high-precision measurements as well as new results regarding the intrinsic energy dependence with some of the commonly used brachytherapy sources. Equations to correct TLD light output to air kerma are outlined and a description of the method to determine the intrinsic energy dependence is presented. For the intrinsic energy dependence investigation, a review of previously published results is presented as well as new experimental results using 125I, 103Pd, 192Ir, and miniature x-ray brachytherapy sources at the University of Wisconsin Medical Radiation Research Center (UWMRRC). The results of these experiments are consistent with previous work and give valuable insight to investigators using TLDs for brachytherapy measurements. - Highlights: • Brachytherapy measurements with LiF:Mg,Ti TLDs performed. • Intrinsic energy dependence for several brachytherapy sources determined. • New LiF:Mg,Ti energy dependence results compared with previous data for x-ray beams. • Uncertainty of LiF:Mg,Ti TLD measurements reviewed

  10. Selection of the important performance influencing factors for the assessment of human error under accident management situations in nuclear power plants

    International Nuclear Information System (INIS)

    This paper introduces the process and final results of selection of the important Performance Influencing Factors (PIFs) under emergency operation and accident management situations in nuclear power plants for use in the assessment of human errors. We collected two types of PIF taxonomies, one is the full set PIF list mainly developed for human error analysis, and the other is the PIFs for human reliability analysis (HRA) in probabilistic safety assessment (PSA). 5 PIF taxonomies among the full set PIF list and 10 PIF taxonomies among HRA methodologies (CREAM, SLIM, INTENT, were collected in this research. By reviewing and analyzing PIFs selected for HRA methodologies, the criterion could be established for the selection of appropriate PIFs under emergency operation and accident management situations. Based on this selection criteria, a new PIF taxonomy was proposed for the assessment of human error under emergency operation and accident management situations in nuclear power plants

  11. The Transition from 2-D Brachytherapy to 3-D High Dose Rate Brachytherapy

    International Nuclear Information System (INIS)

    Brachytherapy is a major treatment modality in the treatment of common cancers including cervical cancer. This publication addresses the recent technological change in brachytherapy treatment planning with better access to 3-D volumetric patient imaging modalities including computed tomography (CT) and magnetic resonance (MR) as opposed to traditional 2-D planar images. In the context of 2-D and 3-D brachytherapy, the publication provides definitions, clinical indications, transitioning milestones, commissioning steps, quality assurance measures, and a related questionnaire. Staff training and resourcing are also addressed. The publication will serve as a guide to radiotherapy departments in Member States who wish to make the transition from 2-D to 3-D brachytherapy

  12. Radiological protection of patients in brachytherapy

    International Nuclear Information System (INIS)

    it will depend on the dose received, hence the importance of proper planning and verification that the treatment is performed according to established procedures. Furthermore, should be borne in mind, that it is very likely that the patient has his last chance to reduce the tumor tissue, and this dose dosage should be adjusted to exactly what was required, keeping in mind, that it is detrimental to the patient, the error of dose delivered in either direction, in other words, by higher or lower doses than the prescribed ones. But the patients, as well as the professionals involved in the practice, will be exposed to stochastic effects, those in which the probability of occurrence depends on the dose received, and then becomes relevant the task of radioprotection, taking into account primarily, that brachytherapy is one of the medical practices in which the proper use of carefully developed and implemented procedures, will optimize the dose in patients and also in the staff. In the paper, a number of incidents and accidents in this practice are revised, to learn from them and not to repeat them. (author)

  13. Use of Monte Carlo Methods in brachytherapy

    International Nuclear Information System (INIS)

    The Monte Carlo method has become a fundamental tool for brachytherapy dosimetry mainly because no difficulties associated with experimental dosimetry. In brachytherapy the main handicap of experimental dosimetry is the high dose gradient near the present sources making small uncertainties in the positioning of the detectors lead to large uncertainties in the dose. This presentation will review mainly the procedure for calculating dose distributions around a fountain using the Monte Carlo method showing the difficulties inherent in these calculations. In addition we will briefly review other applications of the method of Monte Carlo in brachytherapy dosimetry, as its use in advanced calculation algorithms, calculating barriers or obtaining dose applicators around. (Author)

  14. Definition study of the project Dosimetry Brachytherapy

    International Nuclear Information System (INIS)

    The purpose of the research project Dosimetry Brachytherapy is the standardization of calibration methods and quality control procedures used for Brachytherapy sources. Proposals to develop measurement standards and methods for calibrating these sources are presented. Brachytherapy sources will be calibrated in terms of reference airkerma rate or in terms of absorbed dose in water. Therefore, in this project, special attention will be given to the in-phantom measurement method described by Meertens and the use of re-entrant ionisation chambers as transfer standards. In this report, a workplan and time schedule is included. (author). 19 refs.; 1 fig

  15. CT based HDR brachytherapy for intracavitary applications

    International Nuclear Information System (INIS)

    Brachytherapy is most commonly used in combination with external radiotherapy for gynecological cancers of cervix, vagina and endometrium. The characteristic rapid fall off of the dose in brachytherapy makes it useful to deliver a localized high dose to tumor. In gynecological applications the dose limiting critical structures are bladder and rectum. The dose received by rectum and bladder has been an interesting issue all these decades. This work presents the dosimetric and planning aspects of CT based High Dose Rate brachytherapy for intracavitary applications

  16. EM-navigated catheter placement for gynecologic brachytherapy: an accuracy study

    Science.gov (United States)

    Mehrtash, Alireza; Damato, Antonio; Pernelle, Guillaume; Barber, Lauren; Farhat, Nabgha; Viswanathan, Akila; Cormack, Robert; Kapur, Tina

    2014-03-01

    Gynecologic malignancies, including cervical, endometrial, ovarian, vaginal and vulvar cancers, cause significant mortality in women worldwide. The standard care for many primary and recurrent gynecologic cancers consists of chemoradiation followed by brachytherapy. In high dose rate (HDR) brachytherapy, intracavitary applicators and /or interstitial needles are placed directly inside the cancerous tissue so as to provide catheters to deliver high doses of radiation. Although technology for the navigation of catheters and needles is well developed for procedures such as prostate biopsy, brain biopsy, and cardiac ablation, it is notably lacking for gynecologic HDR brachytherapy. Using a benchtop study that closely mimics the clinical interstitial gynecologic brachytherapy procedure, we developed a method for evaluating the accuracy of image-guided catheter placement. Future bedside translation of this technology offers the potential benefit of maximizing tumor coverage during catheter placement while avoiding damage to the adjacent organs, for example bladder, rectum and bowel. In the study, two independent experiments were performed on a phantom model to evaluate the targeting accuracy of an electromagnetic (EM) tracking system. The procedure was carried out using a laptop computer (2.1GHz Intel Core i7 computer, 8GB RAM, Windows 7 64-bit), an EM Aurora tracking system with a 1.3mm diameter 6 DOF sensor, and 6F (2 mm) brachytherapy catheters inserted through a Syed-Neblett applicator. The 3D Slicer and PLUS open source software were used to develop the system. The mean of the targeting error was less than 2.9mm, which is comparable to the targeting errors in commercial clinical navigation systems.

  17. Potential brachytherapy nuclides of future

    International Nuclear Information System (INIS)

    In the past there were relatively few radionuclides available for brachytherapy. But the situation is rapidly changing with the development of many new sources with properties that may be advantageous in certain clinical situations. In the choice of an acceptable, rather than an ideal radionuclide, it is important to consider the physical dose distribution, radiobiological effectiveness, ease of radiation protection, logistics and cost. Taking into account these factors, a number of radionuclides have been tried and more are being considered for specific type of applications. Presently, 137Cs is the most commonly used radionuclide for intracavitary therapy and 192Ir for interstitial therapy. 125I has more or less replaced 198Au for permanent implants. Clinical studies are being carried out to assess the feasibility of replacing 137Cs with 241Am for intracavitary applications and 125I with 103Pd and/or 169Yb for interstitial permanent implants. Other radionuclides being considered are 75Fe and 145Sm. Neutron induced brachytherapy is a new technique being tried to ensure complete radiation safety. (author). 1 tab

  18. Evaluation of functioning of high dose rate brachytherapy at the Instituto Nacional do Cancer

    International Nuclear Information System (INIS)

    Quality control tests are very useful tools to assure the quality of patient's treatment. A daily control of the high dose rate micro selectron was performed based on the security parameters of the equipment and on the quickness of performance. The purpose of this report is to evaluate and to discuss the errors found during the first three years with the high dose rate brachytherapy, at the Instituto Nacional de Cancer. (author)

  19. [Analysis, identification and correction of some errors of model refseqs appeared in NCBI Human Gene Database by in silico cloning and experimental verification of novel human genes].

    Science.gov (United States)

    Zhang, De-Li; Ji, Liang; Li, Yan-Da

    2004-05-01

    We found that human genome coding regions annotated by computers have different kinds of many errors in public domain through homologous BLAST of our cloned genes in non-redundant (nr) database, including insertions, deletions or mutations of one base pair or a segment in sequences at the cDNA level, or different permutation and combination of these errors. Basically, we use the three means for validating and identifying some errors of the model genes appeared in NCBI GENOME ANNOTATION PROJECT REFSEQS: (I) Evaluating the support degree of human EST clustering and draft human genome BLAST. (2) Preparation of chromosomal mapping of our verified genes and analysis of genomic organization of the genes. All of the exon/intron boundaries should be consistent with the GT/AG rule, and consensuses surrounding the splice boundaries should be found as well. (3) Experimental verification by RT-PCR of the in silico cloning genes and further by cDNA sequencing. And then we use the three means as reference: (1) Web searching or in silico cloning of the genes of different species, especially mouse and rat homologous genes, and thus judging the gene existence by ontology. (2) By using the released genes in public domain as standard, which should be highly homologous to our verified genes, especially the released human genes appeared in NCBI GENOME ANNOTATION PROJECT REFSEQS, we try to clone each a highly homologous complete gene similar to the released genes in public domain according to the strategy we developed in this paper. If we can not get it, our verified gene may be correct and the released gene in public domain may be wrong. (3) To find more evidence, we verified our cloned genes by RT-PCR or hybrid technique. Here we list some errors we found from NCBI GENOME ANNOTATION PROJECT REFSEQs: (1) Insert a base in the ORF by mistake which causes the frame shift of the coding amino acid. In detail, abase in the ORF of a gene is a redundant insertion, which causes a reading frame

  20. Comprehensive brachytherapy physical and clinical aspects

    CERN Document Server

    Baltas, Dimos; Meigooni, Ali S; Hoskin, Peter J

    2013-01-01

    Modern brachytherapy is one of the most important oncological treatment modalities requiring an integrated approach that utilizes new technologies, advanced clinical imaging facilities, and a thorough understanding of the radiobiological effects on different tissues, the principles of physics, dosimetry techniques and protocols, and clinical expertise. A complete overview of the field, Comprehensive Brachytherapy: Physical and Clinical Aspects is a landmark publication, presenting a detailed account of the underlying physics, design, and implementation of the techniques, along with practical guidance for practitioners. Bridging the gap between research and application, this single source brings together the technological basis, radiation dosimetry, quality assurance, and fundamentals of brachytherapy. In addition, it presents discussion of the most recent clinical practice in brachytherapy including prostate, gynecology, breast, and other clinical treatment sites. Along with exploring new clinical protocols, ...

  1. Interactive multiobjective optimization for anatomy-based three-dimensional HDR brachytherapy

    Science.gov (United States)

    Ruotsalainen, Henri; Miettinen, Kaisa; Palmgren, Jan-Erik; Lahtinen, Tapani

    2010-08-01

    In this paper, we present an anatomy-based three-dimensional dose optimization approach for HDR brachytherapy using interactive multiobjective optimization (IMOO). In brachytherapy, the goals are to irradiate a tumor without causing damage to healthy tissue. These goals are often conflicting, i.e. when one target is optimized the other will suffer, and the solution is a compromise between them. IMOO is capable of handling multiple and strongly conflicting objectives in a convenient way. With the IMOO approach, a treatment planner's knowledge is used to direct the optimization process. Thus, the weaknesses of widely used optimization techniques (e.g. defining weights, computational burden and trial-and-error planning) can be avoided, planning times can be shortened and the number of solutions to be calculated is small. Further, plan quality can be improved by finding advantageous trade-offs between the solutions. In addition, our approach offers an easy way to navigate among the obtained Pareto optimal solutions (i.e. different treatment plans). When considering a simulation model of clinical 3D HDR brachytherapy, the number of variables is significantly smaller compared to IMRT, for example. Thus, when solving the model, the CPU time is relatively short. This makes it possible to exploit IMOO to solve a 3D HDR brachytherapy optimization problem. To demonstrate the advantages of IMOO, two clinical examples of optimizing a gynecologic cervix cancer treatment plan are presented.

  2. AB012. Brachytherapy for localized prostate cancer

    Science.gov (United States)

    Xu, Yong; Yang, Yong

    2016-01-01

    Background To evaluate the security and effect of brachytherapy for localized prostate cancer. Methods Forty five patients with Tl–T2 prostate cancer were treated with real-time transperineal ultrasound-guide 125I seeds prostate implantation. Results The median operation time was 90 min, the median number of I seeds used was 56. The follow up time was 12–48 months, the cases of PSA Brachytherapy for localized prostate cancer is safe and effective.

  3. A strategy to the development of a human error analysis method for accident management in nuclear power plants using industrial accident dynamics

    International Nuclear Information System (INIS)

    This technical report describes the early progress of he establishment of a human error analysis method as a part of a human reliability analysis(HRA) method for the assessment of the human error potential in a given accident management strategy. At first, we review the shortages and limitations of the existing HRA methods through an example application. In order to enhance the bias to the quantitative aspect of the HRA method, we focused to the qualitative aspect, i.e., human error analysis(HEA), during the proposition of a strategy to the new method. For the establishment of a new HEA method, we discuss the basic theories and approaches to the human error in industry, and propose three basic requirements that should be maintained as pre-requisites for HEA method in practice. Finally, we test IAD(Industrial Accident Dynamics) which has been widely utilized in industrial fields, in order to know whether IAD can be so easily modified and extended to the nuclear power plant applications. We try to apply IAD to the same example case and develop new taxonomy of the performance shaping factors in accident management and their influence matrix, which could enhance the IAD method as an HEA method. (author). 33 refs., 17 tabs., 20 figs

  4. The American Brachytherapy Society recommendations for low-dose-rate brachytherapy for carcinoma of the cervix

    International Nuclear Information System (INIS)

    Purpose: This report presents guidelines for using low-dose-rate (LDR) brachytherapy in the management of patients with cervical cancer. Methods: Members of the American Brachytherapy Society (ABS) with expertise in LDR brachytherapy for cervical cancer performed a literature review, supplemented by their clinical experience, to formulate guidelines for LDR brachytherapy of cervical cancer. Results: The ABS strongly recommends that radiation treatment for cervical carcinoma (with or without chemotherapy) should include brachytherapy as a component. Precise applicator placement is essential for improved local control and reduced morbidity. The outcome of brachytherapy depends, in part, on the skill of the brachytherapist. Doses given by external beam radiotherapy and brachytherapy depend upon the initial volume of disease, the ability to displace the bladder and rectum, the degree of tumor regression during pelvic irradiation, and institutional practice. The ABS recognizes that intracavitary brachytherapy is the standard technique for brachytherapy for cervical carcinoma. Interstitial brachytherapy should be considered for patients with disease that cannot be optimally encompassed by intracavitary brachytherapy. The ABS recommends completion of treatment within 8 weeks, when possible. Prolonging total treatment duration can adversely affect local control and survival. Recommendations are made for definitive and postoperative therapy after hysterectomy. Although recognizing that many efficacious LDR dose schedules exist, the ABS presents suggested dose and fractionation schemes for combining external beam radiotherapy with LDR brachytherapy for each stage of disease. The dose prescription point (point A) is defined for intracavitary insertions. Dose rates of 0.50 to 0.65 Gy/h are suggested for intracavitary brachytherapy. Dose rates of 0.50 to 0.70 Gy/h to the periphery of the implant are suggested for interstitial implant. Use of differential source activity or

  5. Radiation Protection in Brachytherapy. Report of the SEFM Task Group on Brachytherapy

    International Nuclear Information System (INIS)

    This document presents the report of the Brachytherapy Task Group of the Spanish Society of Medical Physics. It is dedicated to the radiation protection aspects involved in brachytherapy. The aim of this work is to include the more relevant aspects related to radiation protection issues that appear in clinical practice, and for the current equipment in Spain. Basically this report focuses on the typical contents associated with high dose rate brachytherapy with 192Ir and 60Co sources, and permanent seed implants with 125I, 103Pd and 131Cs, which are the most current and widespread modalities. Ophthalmic brachytherapy (COMS with 125I, 106Ru, 90Sr) is also included due to its availability in a significant number of spanish hospitals. The purpose of this report is to assist to the medical physicist community in establishing a radiation protection program for brachytherapy procedures, trying to solve some ambiguities in the application of legal requirements and recommendations in clinical practice. (Author)

  6. Team errors: definition and taxonomy

    International Nuclear Information System (INIS)

    In error analysis or error management, the focus is usually upon individuals who have made errors. In large complex systems, however, most people work in teams or groups. Considering this working environment, insufficient emphasis has been given to 'team errors'. This paper discusses the definition of team errors and its taxonomy. These notions are also applied to events that have occurred in the nuclear power industry, aviation industry and shipping industry. The paper also discusses the relations between team errors and Performance Shaping Factors (PSFs). As a result, the proposed definition and taxonomy are found to be useful in categorizing team errors. The analysis also reveals that deficiencies in communication, resource/task management, excessive authority gradient, excessive professional courtesy will cause team errors. Handling human errors as team errors provides an opportunity to reduce human errors

  7. A brachytherapy model-based dose calculation algorithm -AMIGOBrachy

    International Nuclear Information System (INIS)

    Brachytherapy treatments have been performed based on TG-43U1 water dose formalism which neglects human tissues density and composition, body interfaces and applicator effects. As these effects could be relevant for brachytherapy energy range, modern treatment planning systems (TPS) are now available that are based on model-based dose calculation algorithms (MBDCA) enabling heterogeneity corrections, which are needed to replace the TG-43U1 water dose formalism for a more accurate approach. The recently published AAPM TG-186 report is the first step towards to a TPS taking into account heterogeneities, applicators and human body complexities. This report presents the current status, recommendations for clinical implementation and specifies research areas where considerable efforts are necessary to move forward with MBDCA. Monte Carlo (MC) codes are an important part of the current algorithms due their flexibility and accuracy, although, almost all MC codes present no interface to process the large amount of data necessary to perform clinical cases simulations, which may include hundreds of dwell positions, inter-seed attenuation, image processing and others time consuming issues that can make MC simulation unfeasible without a pre-processing interface. This work presents the AMIGOBrachy interface tool (Algorithm for Medical Image-based Generating Object - Brachytherapy module) which provides all the pre-processing task needed for the simulation. This software can import and edit treatments plans from BrachyVision™ (Varian Medical Systems, Inc., Palo Alto, CA) and ONCENTRA™ (Elekta AB, Stockholm, Sweden), and also create a new plan through contouring resources, needle recognition, HU segmentation, combining voxels phantoms with analytical geometries to define applicators and other resources used to create MCNP5 input and analyze the results. This work presents some results used to validate the software and to evaluate the heterogeneities impact in a clinical case

  8. Intraluminal brachytherapy in treatment of malignant obstructive jaundice

    International Nuclear Information System (INIS)

    Objective: To study the practicability and preliminary effect of intraluminal brachytherapy in treatment of malignant obstructive jaundice. Methods: Intraluminal brachytherapy was performed in 4 patients who had been treated with biliary stent implantation. Results: No complications related to intraluminal brachytherapy had happened. One patient was followed up by means of CT, showing reduction in tumor size. Conclusion: Intraluminal brachytherapy is a safe and effective method in treating malignant tumor causing obstructive jaundice

  9. Implementation Of National And International Requirements In A NUCLEAR Safety And Control System For Human Error Decrease

    International Nuclear Information System (INIS)

    Considering the continuous evolution of Nuclear Safety Requirements standards and norms as well as technological ageing of some of the TRIGA 14MW systems since 2007 the Institute for Nuclear Research Pitesti started an ambitious program that aims at modernize different reactor systems: main cooling circuit, TRIGA SSR 14MW console and safety system, ventilation system, purification circuit, dosimetric system, loop A irradiation device. The modernization projects for process apply the national and international regulations and recommendations concerning: - physical and functional separation between safety and control components; - educing the probability of human error occurrence; - ensuring the continuous monitoring. Reactor Protection System (RPS) is designed for safe shutdown of the reactor. The RPS is responsible for the initiating signal that triggers the Scram protective action in case of anticipated operational occurrences, incident conditions or design basis accidents. RPS can scram automatically, or it can be tripped by the operators. Scram occurs when the safety parameters reach a limit set point called Safety System Setting (SSS). (authors)

  10. The Error in Total Error Reduction

    OpenAIRE

    Witnauer, James E.; Urcelay, Gonzalo P.; Miller, Ralph R.

    2013-01-01

    Most models of human and animal learning assume that learning is proportional to the discrepancy between a delivered outcome and the outcome predicted by all cues present during that trial (i.e., total error across a stimulus compound). This total error reduction (TER) view has been implemented in connectionist and artificial neural network models to describe the conditions under which weights between units change. Electrophysiological work has revealed that the activity of dopamine neurons i...

  11. Brachytherapy next generation: robotic systems.

    Science.gov (United States)

    Popescu, Tiberiu; Kacsó, Alex Cristian; Pisla, Doina; Kacsó, Gabriel

    2015-12-01

    In a field dominated by external beam radiation therapy (EBRT), both the therapeutic and technical possibilities of brachytherapy (BT) are underrated, shadowed by protons and intensity modulated radiotherapy. Decreasing expertise and indications, as well as increasing lack of specific BT training for radiation therapy (RT) residents led to the real need of shortening its learning curve and making it more popular. Developing robotic BT devices can be a way to mitigate the above issues. There are many teams working at custom-made robotic BT platforms to perfect and overcome the limitations of the existing systems. This paper provides a picture of the current state-of-the-art in robotic assisted BT, as it also conveys the author's solution to the problem, a parallel robot that uses CT-guidance. PMID:26816510

  12. 10 CFR 35.432 - Calibration measurements of brachytherapy sources.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Calibration measurements of brachytherapy sources. 35.432 Section 35.432 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.432 Calibration measurements of brachytherapy sources. (a) Before the first medical use of...

  13. 10 CFR 35.406 - Brachytherapy sources accountability.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Brachytherapy sources accountability. 35.406 Section 35.406 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.406 Brachytherapy sources accountability. (a) A licensee shall maintain accountability at all...

  14. Navigation system for interstitial brachytherapy

    International Nuclear Information System (INIS)

    The purpose of the stud was to develop a computed tomography (CT) based electromagnetic navigation system for interstitial brachytherapy. This is especially designed for situations when needles have to be positioned adjacent to or within critical anatomical structures. In such instances interactive 3D visualisation of the needle positions is essential. The material consisted of a Polhemus electromagnetic 3D digitizer, a Pentium 200 MHz laptop and a voice recognition for continuous speech. In addition, we developed an external reference system constructed of Perspex which could be positioned above the tumour region and attached to the patient using a non-invasive fixation method. A specially designed needle holder and patient bed were also developed. Measurements were made on a series of phantoms in order to study the efficacy and accuracy of the navigation system. The mean navigation accuracy of positioning the 20.0 cm length metallic needles within the phantoms was in the range 2.0-4.1 mm with a maximum of 5.4 mm. This is an improvement on the accuracy of a CT-guided technique which was in the range 6.1-11.3 mm with a maximum of 19.4 mm. The mean reconstruction accuracy of the implant geometry was 3.2 mm within a non-ferromagnetic environment. We found that although the needles were metallic this did not have a significant influence. We also found for our experimental setups that the CT table and operation table non-ferromagnetic parts had no significant influence on the navigation accuracy. This navigation system will be a very useful clinical tool for interstitial brachytherapy applications, particularly when critical structures have to be avoided. It also should provide a significant improvement on our existing technique

  15. Image guided Brachytherapy: The paradigm of Gynecologic and Partial Breast HDR Brachytherapy

    Science.gov (United States)

    Diamantopoulos, S.; Kantemiris, I.; Konidari, A.; Zaverdinos, P.

    2015-09-01

    High dose rate (HDR) brachytherapy uses high strength radioactive sources and temporary interstitial implants to conform the dose to target and minimize the treatment time. The advances of imaging technology enable accurate reconstruction of the implant and exact delineation of high-risk CTV and the surrounding critical structures. Furthermore, with sophisticated treatment planning systems, applicator devices and stepping source afterloaders, brachytherapy evolved to a more precise, safe and individualized treatment. At the Radiation Oncology Department of Metropolitan Hospital Athens, MRI guided HDR gynecologic (GYN) brachytherapy and accelerated partial breast irradiation (APBI) with brachytherapy are performed routinely. Contouring and treatment planning are based on the recommendations of the GEC - ESTRO Working group. The task of this presentation is to reveal the advantages of 3D image guided brachytherapy over 2D brachytherapy. Thus, two patients treated at our department (one GYN and one APBI) will be presented. The advantage of having adequate dose coverage of the high risk CTV and simultaneous low doses to the OARs when using 3D image- based brachytherapy will be presented. The treatment techniques, equipment issues, as well as implantation, imaging and treatment planning procedures will be described. Quality assurance checks will be treated separately.

  16. Payment Error Rate Measurement (PERM)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The PERM program measures improper payments in Medicaid and CHIP and produces error rates for each program. The error rates are based on reviews of the...

  17. In vivo photoacoustic imaging of prostate brachytherapy seeds

    Science.gov (United States)

    Lediju Bell, Muyinatu A.; Kuo, Nathanael P.; Song, Danny Y.; Kang, Jin; Boctor, Emad M.

    2014-03-01

    We conducted an approved canine study to investigate the in vivo feasibility of photoacoustic imaging for intraoperative updates to brachytherapy treatment plans. Brachytherapy seeds coated with black ink were inserted into the canine prostate using methods similar to a human procedure. A transperineal, interstitial, fiber optic light delivery method, coupled to a 1064 nm laser, was utilized to irradiate the prostate and the resulting acoustic waves were detected with a transrectal ultrasound probe. The fiber was inserted into a high dose rate (HDR) brachytherapy needle that acted as a light-diffusing sheath, enabling radial light delivery from the tip of the fiber inside the sheath. The axis of the fiber was located at a distance of 4-9 mm from the long axis of the cylindrical seeds. Ultrasound images acquired with the transrectal probe and post-operative CT images of the implanted seeds were analyzed to confirm seed locations. In vivo limitations with insufficient light delivery within the ANSI laser safety limit (100 mJ/cm2) were overcome by utilizing a short-lag spatial coherence (SLSC) beamformer, which provided average seed contrasts of 20-30 dB for energy densities ranging 8-84 mJ/cm2. The average contrast was improved by up to 20 dB with SLSC beamforming compared to conventional delay-and-sum beamforming. There was excellent agreement between photoacoustic, ultrasound, and CT images. Challenges included visualization of photoacoustic artifacts that corresponded with locations of the optical fiber and hyperechoic tissue structures.

  18. A multicentre ‘end to end’ dosimetry audit for cervix HDR brachytherapy treatment

    International Nuclear Information System (INIS)

    Purpose: To undertake the first multicentre fully ‘end to end’ dosimetry audit for HDR cervix brachytherapy, comparing planned and delivered dose distributions around clinical treatment applicators, with review of local procedures. Materials and methods: A film-dosimetry audit was performed at 46 centres, including imaging, applicator reconstruction, treatment planning and delivery. Film dose maps were calculated using triple-channel dosimetry and compared to RTDose data from treatment planning systems. Deviations between plan and measurement were quantified at prescription Point A and using gamma analysis. Local procedures were also discussed. Results: The mean difference between planned and measured dose at Point A was −0.6% for plastic applicators and −3.0% for metal applicators, at standard uncertainty 3.0% (k = 1). Isodose distributions agreed within 1 mm over a dose range 2–16 Gy. Mean gamma passing rates exceeded 97% for plastic and metal applicators at 3% (local) 2 mm criteria. Two errors were found: one dose normalisation error and one applicator library misaligned with the imaged applicator. Suggestions for quality improvement were also made. Conclusions: The concept of ‘end to end’ dosimetry audit for HDR brachytherapy has been successfully implemented in a multicentre environment, providing evidence that a high level of accuracy in brachytherapy dosimetry can be achieved

  19. Errors and violations

    International Nuclear Information System (INIS)

    This paper is in three parts. The first part summarizes the human failures responsible for the Chernobyl disaster and argues that, in considering the human contribution to power plant emergencies, it is necessary to distinguish between: errors and violations; and active and latent failures. The second part presents empirical evidence, drawn from driver behavior, which suggest that errors and violations have different psychological origins. The concluding part outlines a resident pathogen view of accident causation, and seeks to identify the various system pathways along which errors and violations may be propagated

  20. ACPSEM brachytherapy working group recommendations for quality assurance in brachytherapy

    International Nuclear Information System (INIS)

    The Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) Radiation Oncology Specialty Group (ROSG) formed a series of working groups in 2011 to develop recommendation papers for guidance of radiation oncology medical physics practice within the Australasian setting. These recommendations are intended to provide guidance for safe work practices and a suitable level of quality control without detailed work instructions. It is the responsibility of the medical physicist to ensure that locally available equipment and procedures are sufficiently sensitive to establish compliance to these recommendations. The recommendations are endorsed by the ROSG, have been subject to independent expert reviews and have also been approved by the ACPSEM Council. For the Australian audience, these recommendations should be read in conjunction with the Tripartite Radiation Oncology Practice Standards. This publication presents the recommendations of the ACPSEM Brachytherapy Working Group (BTWG) and has been developed in alignment with other international associations. However, these recommendations should be read in conjunction with relevant national, state or territory legislation and local requirements, which take precedence over the ACPSEM recommendation papers. It is hoped that the users of this and other ACPSEM recommendation papers will contribute to the development of future versions through the Radiation Oncology Specialty Group of the ACPSEM.

  1. Local anesthesia for prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To demonstrate the technique and feasibility of prostate brachytherapy performed with local anesthesia only. Methods and Materials: A 5 by 5 cm patch of perineal skin and subcutaneous tissue is anesthetized by local infiltration of 10 cc of 1% lidocaine with epinephrine, using a 25-gauge 5/8-inch needle. Immediately following injection into the subcutaneous tissues, the deeper tissues, including the pelvic floor and prostate apex, are anesthetized by injecting 15 cc lidocaine solution with approximately 8 passes of a 20-gauge 1.0-inch needle. Following subcutaneous and peri-apical lidocaine injections, the patient is brought to the simulator suite and placed in leg stirrups. The transrectal ultrasound (TRUS) probe is positioned to reproduce the planning images and a 3.5- or 6.0-inch, 22-gauge spinal needle is inserted into the peripheral planned needle tracks, monitored by TRUS. When the tips of the needles reach the prostatic base, about 1 cc of lidocaine solution is injected in the intraprostatic track, as the needle is slowly withdrawn, for a total volume of 15 cc. The implants are done with a Mick Applicator, inserting and loading groups of two to four needles, so that a maximum of only about four needles are in the patient at any one time. During the implant procedure, an additional 1 cc of lidocaine solution is injected into one or more needle tracks if the patient experiences substantial discomfort. The total dose of lidocaine is generally limited to 500 mg (50 ml of 1% solution). Results: To date, we have implanted approximately 50 patients in our simulator suite, using local anesthesia. Patients' heart rate and diastolic blood pressure usually showed moderate changes, consistent with some discomfort. The time from first subcutaneous injection and completion of the source insertion ranged from 35 to 90 minutes. Serum lidocaine levels were below or at the low range of therapeutic. There has been only one instance of acute urinary retention in the

  2. In-phantom dosimetric measurements as quality control for brachytherapy. System check and constancy check; Messungen im Festkoerperphantom als Qualitaetskontrolle in der Brachytherapie. Systempruefung und Konstanzpruefung

    Energy Technology Data Exchange (ETDEWEB)

    Kollefrath, Michael; Bruggmoser, Gregor; Nanko, Norbert; Gainey, Mark [Universitaetsklinik Freiburg (Germany). Klinik fuer Strahlenheilkunde

    2015-09-01

    In brachytherapy dosimetric measurements are difficult due to the inherent dose-inhomogeneities. Typically in routine clinical practice only the nominal dose rate is determined for computer controlled afterloading systems. The region of interest lies close to the source when measuring the spatial dose distribution. In this region small errors in the positioning of the detector, and its finite size, lead to large measurement uncertainties that exacerbate the routine dosimetric control of the system in the clinic. The size of the measurement chamber, its energy dependence, and the directional dependence of the measurement apparatus are the factors which have a significant influence on dosimetry. Although ionisation chambers are relatively large, they are employed since similar chambers are commonly found on clinical brachytherapy units. The dose is determined using DIN 6800 [11] since DIN 6809-2 [12], which deals with dosimetry in brachytherapy, is antiquated and is currently in the process of revision. Further information regarding dosimetry for brachytherapy can be found in textbooks [1] and [2]. The measurements for this work were performed with a HDR (High-Dose-Rate) {sup 192}Ir source, type mHDR V2, and a Microselectron Afterloader V2 both from Nucletron/Elekta. In this work two dosimetric procedures are presented which, despite the aforemention difficulties, should assist in performing checks of the proper operation of the system. The first is a system check that measures the dose distribution along a line and is to be performed when first bringing the afterloader into operation, or after significant changes to the system. The other is a dosimetric constancy check, which with little effort can be performed monthly or weekly. It simultaneously verifies the positioning of the source at two positions, the functionality of the system clock and the automatic re-calculation of the source activity.

  3. Identification of causes of human errors in support of the development of intelligent computer-assisted instruction systems for plant operator training

    International Nuclear Information System (INIS)

    This paper proposes a methodology to identify causes of human error in the operation of plant systems to support the development of CAI system for operator training. The target task of this methodology is goal-driven and knowledge-based planning behaviour, the cognitive process of which is assumed to be modeled as means-end analysis. The methodology uses four criteria to classify errors in an operation into eight groups, and then asks the trainee several questions to prune the causes. To confirm the usefulness of this methodology, a prototype CAI system is developed for the operation of filling up sodium into the primary coolant system of a liquid-metal-cooled fast reactor. The experimental result indicates that the system has the capability of identifying causes of the trainee's error, and consequently of figuring out the characteristics of his/her defect. As a result of this study, several issues are identified for future research

  4. Comparison of dose calculation methods for brachytherapy of intraocular tumors

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, Mark J.; Chiu-Tsao, Sou-Tung; Finger, Paul T.; Meigooni, Ali S.; Melhus, Christopher S.; Mourtada, Firas; Napolitano, Mary E.; Rogers, D. W. O.; Thomson, Rowan M.; Nath, Ravinder [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Quality MediPhys LLC, Denville, New Jersey 07834 (United States); New York Eye Cancer Center, New York, New York 10065 (United States); Department of Radiation Oncology, Comprehensive Cancer Center of Nevada, Las Vegas, Nevada 89169 (United States); Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Department of Radiation Physics, University of Texas, M.D. Anderson Cancer Center, Houston, Texas 77030 (United States) and Department of Experimental Diagnostic Imaging, University of Texas, M.D. Anderson Cancer Center, Houston, Texas 77030 (United States); Physics, Elekta Inc., Norcross, Georgia 30092 (United States); Department of Physics, Carleton University, Ottawa, Ontario K1S 5B6 (Canada); Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520 (United States)

    2011-01-15

    -axis points-of-interest, dose differences approached factors of 7 and 12 at some positions for {sup 125}I and {sup 103}Pd, respectively. There was good agreement ({approx}3%) among MC codes and Plaque Simulator results when appropriate parameters calculated using MC codes were input into Plaque Simulator. Plaque Simulator and MC users are perhaps at risk of overdosing patients up to 20% if heterogeneity corrections are used and the prescribed dose is not modified appropriately. Conclusions: Agreement within 2% was observed among conventional brachytherapy TPS and MC codes for intraocular brachytherapy dose calculations in a homogeneous water environment. In general, the magnitude of dose errors incurred by ignoring the effect of the plaque backing and Silastic insert (i.e., by using the TG-43 approach) increased with distance from the plaque's central-axis. Considering the presence of material heterogeneities in a typical eye plaque, the best method in this study for dose calculations is a verified MC simulation.

  5. Simulation study on potential accuracy gains from dual energy CT tissue segmentation for low-energy brachytherapy Monte Carlo dose calculations

    Science.gov (United States)

    Landry, Guillaume; Granton, Patrick V.; Reniers, Brigitte; Öllers, Michel C.; Beaulieu, Luc; Wildberger, Joachim E.; Verhaegen, Frank

    2011-10-01

    This work compares Monte Carlo (MC) dose calculations for 125I and 103Pd low-dose rate (LDR) brachytherapy sources performed in virtual phantoms containing a series of human soft tissues of interest for brachytherapy. The geometries are segmented (tissue type and density assignment) based on simulated single energy computed tomography (SECT) and dual energy (DECT) images, as well as the all-water TG-43 approach. Accuracy is evaluated by comparison to a reference MC dose calculation performed in the same phantoms, where each voxel's material properties are assigned with exactly known values. The objective is to assess potential dose calculation accuracy gains from DECT. A CT imaging simulation package, ImaSim, is used to generate CT images of calibration and dose calculation phantoms at 80, 120, and 140 kVp. From the high and low energy images electron density ρe and atomic number Z are obtained using a DECT algorithm. Following a correction derived from scans of the calibration phantom, accuracy on Z and ρe of ±1% is obtained for all soft tissues with atomic number Z in [6,8] except lung. GEANT4 MC dose calculations based on DECT segmentation agreed with the reference within ±4% for 103Pd, the most sensitive source to tissue misassignments. SECT segmentation with three tissue bins as well as the TG-43 approach showed inferior accuracy with errors of up to 20%. Using seven tissue bins in our SECT segmentation brought errors within ±10% for 103Pd. In general 125I dose calculations showed higher accuracy than 103Pd. Simulated image noise was found to decrease DECT accuracy by 3-4%. Our findings suggest that DECT-based segmentation yields improved accuracy when compared to SECT segmentation with seven tissue bins in LDR brachytherapy dose calculation for the specific case of our non-anthropomorphic phantom. The validity of our conclusions for clinical geometry as well as the importance of image noise in the tissue segmentation procedure deserves further

  6. Brachytherapy on treatment of childhood rhabdomyosarcoma

    International Nuclear Information System (INIS)

    A retrospective study of 21 children with rhabdomyosarcoma treated by brachytherapy to the primary site of the tumor between january/1980 to june/1993 was undertaken. The main objectives were: to comprove the utility of brachytherapy in childhood rhabdomyosarcoma, to evaluate the local control and survival in association with chemotherapy, to analyze the late effects of the treatment and to determinate the preferencial technique to each clinical situation. Seventeen patients were female and four male with a median age of five years (range of 3 months to 15 years). Seven children showed head and neck tumors, seven in extremities, five genital, one perineal and one in trunk. Four patients were group II, fifteen group III and two group IV according the Intergroup Rhabdomyosarcoma Study (IRS) classification. The histologic type presented eighteen embryonary rhabdomyosarcoma, one alveolar rhabdomyosarcoma and in two patients was not possible to be determined. The therapeutic approach included induction chemotherapy followed by radiotherapy to the primary site in association or not with surgical ressection and maintenance chemotherapy. All patients received brachytherapy to the tumor site. The radioactive isotopes employed were: Gold198, Cesium137 and Iridium192. The brachytherapy techniques depended on the tumor site, period of treatment, availability of the radioactive material and stage of the disease. Patients treated exclusively by brachytherapy received 40Gy to 60Gy. When brachytherapy was associated with external radiotherapy the dose ranged from 20Gy to 40Gy. Local control was achieved in 18 of 20 patients (90%). The global survival and local control survival rates were 61.9% ((13(21)) patients) and 72.2% ((13(18)) patients) respectively. Staging and age showed statistic significance for survival. Distant metastasis occurred in seven patients (33.3%), mainly to the lungs. Patients treated with total radiation dose higher than 45Gy showed more incidence of

  7. Dosimetric calculus in intravascular brachytherapy

    International Nuclear Information System (INIS)

    Among the cardiovascular diseases, the most common is acute myocardial infarction, which occurs because of the occlusion of one or more coronary arteries. Balloon angioplasty has been a popular treatment which is less invasive than surgeries involving revascularization of the myocardium, thus promising a better quality of life for patients. Unfortunately, the rate of restenosis (re-closing of the vessel) after balloon angioplasty is high (approximately 30-50% within the first year after treatment). Known as Intravascular Brachytherapy, the technique has been used with several radiation sources, and researchers have obtained success in decreasing the rate of restenosis. In order to study the radiation dosimetry in the patient and radiological protection for this therapy, radiation dose distributions for monoenergetic electrons and photons (at nine discrete energies) were calculated for blood vessels of diameter 0.15, 0.30 and 0.45 cm with balloon and wire sources using the radiation transport code MCNP4B. Specific calculations were carried out for several radionuclides. Two stent sources employing 32P are also simulated. Advantages and disadvantages of the radionuclides and source geometries are discussed and the dosimetry developed here will aid in the realization of the benefits obtained in patients. (author)

  8. In vivo visualization of prostate brachytherapy seeds with photoacoustic imaging

    Science.gov (United States)

    Lediju Bell, Muyinatu A.; Kuo, Nathanael P.; Song, Danny Y.; Kang, Jin U.; Boctor, Emad M.

    2014-12-01

    We conducted a canine study to investigate the in vivo feasibility of photoacoustic imaging for intraoperative updates to brachytherapy treatment plans. A fiber coupled to a 1064-nm Nd:YAG laser was inserted into high-dose-rate brachytherapy needles, which diffused light spherically. These needles were inserted through the perineum into the prostate for interstitial light delivery and the resulting acoustic waves were detected with a transrectal ultrasound probe. Postoperative computed tomography images and ex vivo photoacoustic images confirmed seed locations. Limitations with insufficient light delivery were mitigated with short-lag spatial coherence (SLSC) beamforming, providing a 10-20 dB contrast improvement over delay-and-sum (DAS) beamforming for pulse energies ranging from 6.8 to 10.5 mJ with a fiber-seed distance as large as 9.5 mm. For the same distance and the same range of energy densities, signal-to-noise ratios (SNRs) were similar while the contrast-to-noise ratio (CNR) was higher in SLSC compared to DAS images. Challenges included visualization of signals associated with the interstitial fiber tip and acoustic reverberations between seeds separated by ≤2 mm. Results provide insights into the potential for clinical translation to humans.

  9. Cure of cervical cancer using 252Cf neutron brachytherapy

    International Nuclear Information System (INIS)

    252Cf neutron brachytherapy was tested in a feasibility trial for efficacy for cervix cancer therapy vs. high stage radioresistant and subsequently for all stages of disease. Actuarial survival curves were analyzed for 218 patients treated between 1976 and 1983 and followed five to 14 years to the present time. A variety of doses, schedules and methods for brachytherapy was tested during this period, and a dose-response relationship for tumor eradication studied. All treatments were combined with whole-pelvis photon radiotherapy to approximately 45 to 60 Gy. This combination was found effective, particularly if an early implant schedule was used for the Cf implant, followed by whole-pelvis photon radiotherapy. For bulk/barrel shaped low-stage disease in medically fit patients, 252Cf implants were combined with surgery, i.e., extrafascial hysterectomy and was readily usable for treatment without complications and with high cure rates (92% five-year survival). All survivals and outcomes to 13 years match the best results of conventional photon radiotherapy. For all stages better results were observed for bulky, barrel, and advanced-stage tumors, especially for local tumor control, if optimal schedules, doses and implant numbers were used. Knowledge about neutron dose, dose per implant, number of implants and combination with photon beam therapy evolved during the trials. 252Cf represents a new quickacting effective radioisotope for human cancer therapy especially for treatment of radioresistant, bulky and high stage cancers. (orig.)

  10. Medical physics aspects of ophthalmic brachytherapy

    International Nuclear Information System (INIS)

    Intraocular melanoma is the most common primary malignancy of the eye. Radiation therapy using ophthalmic plaque has proved successful in the management of various ocular lesions. Although a few centres were using 90Sr/90Y plaques for shallow turtlours some years ago, eye plaque therapy was not a common practice in India. A revived interest in the use of eye plaque therapy and very high cost of imported sources has led to the development and production of 125I seed sources by the Radiopharmaceuticals Division, BARC. This report presents a brief description on the clinical, dosimetry and radiation safety aspects of 90Sr/90Y and 106Ru/106Rh beta ray and 125I gamma ray eye plaque applicators. This report has been divided in five Sections. Section I presents general introduction of ophthalmic brachytherapy including the structure of a human eye, types of ophthalmic plaques and characteristics of radioisotopes commonly used in such applications. A brief review of sources, applicators and dosimetry of 90Sr/90Y and 106Ru/106Rh beta and 125I gamma ophthalmic plaques are given in Section II and Section III, respectively. Section IV contains the single seed dosimetry data of BARC OcuProsta 125I seed as well as dosimetry data of typical eye plaques loaded with BARC OcuProsta 125I seed. Quality assurance and radiation safety aspects of these eye applicators are described in Section V. A proforma of the application required to be filled in by the user institution for obtaining regulatory consent to start eye plaque therapy has also been appended to this report. (author)

  11. Insight and Lessons Learned on Organizational Factors and Safety Culture from the Review of Human Error-related Events of NPPs in Korea

    International Nuclear Information System (INIS)

    Event investigation is one of the key means of enhancing nuclear safety deriving effective measures and preventing recurrences. However, it is difficult to analyze organizational factors and safety culture. This paper tries to review human error-related events from perspectives of organizational factors and safety culture, and to derive insights and lessons learned in developing the regulatory infrastructure of plant oversight on safety culture

  12. Insight and Lessons Learned on Organizational Factors and Safety Culture from the Review of Human Error-related Events of NPPs in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Tae; Lee, Dhong Hoon; Choi, Young Sung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2014-08-15

    Event investigation is one of the key means of enhancing nuclear safety deriving effective measures and preventing recurrences. However, it is difficult to analyze organizational factors and safety culture. This paper tries to review human error-related events from perspectives of organizational factors and safety culture, and to derive insights and lessons learned in developing the regulatory infrastructure of plant oversight on safety culture.

  13. Analysis of human error in occupational accidents in the power plant industries using combining innovative FTA and meta-heuristic algorithms

    Directory of Open Access Journals (Sweden)

    M. Omidvari

    2015-09-01

    Full Text Available Introduction: Occupational accidents are of the main issues in industries. It is necessary to identify the main root causes of accidents for their control. Several models have been proposed for determining the accidents root causes. FTA is one of the most widely used models which could graphically establish the root causes of accidents. The non-linear function is one of the main challenges in FTA compliance and in order to obtain the exact number, the meta-heuristic algorithms can be used. Material and Method: The present research was done in power plant industries in construction phase. In this study, a pattern for the analysis of human error in work-related accidents was provided by combination of neural network algorithms and FTA analytical model. Finally, using this pattern, the potential rate of all causes was determined. Result: The results showed that training, age, and non-compliance with safety principals in the workplace were the most important factors influencing human error in the occupational accident. Conclusion: According to the obtained results, it can be concluded that human errors can be greatly reduced by training, right choice of workers with regard to the type of occupations, and provision of appropriate safety conditions in the work place.

  14. BrachyView, a novel in-body imaging system for HDR prostate brachytherapy: Experimental evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Safavi-Naeini, M.; Han, Z.; Alnaghy, S.; Cutajar, D.; Petasecca, M.; Lerch, M. L. F.; Rosenfeld, A. B., E-mail: anatoly@uow.edu.au [Centre for Medical Radiation Physics, University of Wollongong, Wollongong 2522 (Australia); Franklin, D. R. [Faculty of Engineering and Information Technology, University of Technology, Sydney 2007 (Australia); Bucci, J. [St George Hospital Cancer Care Centre, Kogarah 2217 (Australia); Carrara, M. [Fondazione IRCCS Istituto Nazionale dei Tumori, Milan 20133 (Italy); Zaider, M. [Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States)

    2015-12-15

    Purpose: This paper presents initial experimental results from a prototype of high dose rate (HDR) BrachyView, a novel in-body source tracking system for HDR brachytherapy based on a multipinhole tungsten collimator and a high resolution pixellated silicon detector array. The probe and its associated position estimation algorithms are validated and a comprehensive evaluation of the accuracy of its position estimation capabilities is presented. Methods: The HDR brachytherapy source is moved through a sequence of positions in a prostate phantom, for various displacements in x, y, and z. For each position, multiple image acquisitions are performed, and source positions are reconstructed. Error estimates in each dimension are calculated at each source position and combined to calculate overall positioning errors. Gafchromic film is used to validate the accuracy of source placement within the phantom. Results: More than 90% of evaluated source positions were estimated with an error of less than one millimeter, with the worst-case error being 1.3 mm. Experimental results were in close agreement with previously published Monte Carlo simulation results. Conclusions: The prototype of HDR BrachyView demonstrates a satisfactory level of accuracy in its source position estimation, and additional improvements are achievable with further refinement of HDR BrachyView’s image processing algorithms.

  15. BrachyView, a novel in-body imaging system for HDR prostate brachytherapy: Experimental evaluation

    International Nuclear Information System (INIS)

    Purpose: This paper presents initial experimental results from a prototype of high dose rate (HDR) BrachyView, a novel in-body source tracking system for HDR brachytherapy based on a multipinhole tungsten collimator and a high resolution pixellated silicon detector array. The probe and its associated position estimation algorithms are validated and a comprehensive evaluation of the accuracy of its position estimation capabilities is presented. Methods: The HDR brachytherapy source is moved through a sequence of positions in a prostate phantom, for various displacements in x, y, and z. For each position, multiple image acquisitions are performed, and source positions are reconstructed. Error estimates in each dimension are calculated at each source position and combined to calculate overall positioning errors. Gafchromic film is used to validate the accuracy of source placement within the phantom. Results: More than 90% of evaluated source positions were estimated with an error of less than one millimeter, with the worst-case error being 1.3 mm. Experimental results were in close agreement with previously published Monte Carlo simulation results. Conclusions: The prototype of HDR BrachyView demonstrates a satisfactory level of accuracy in its source position estimation, and additional improvements are achievable with further refinement of HDR BrachyView’s image processing algorithms

  16. Error mode prediction.

    Science.gov (United States)

    Hollnagel, E; Kaarstad, M; Lee, H C

    1999-11-01

    The study of accidents ('human errors') has been dominated by efforts to develop 'error' taxonomies and 'error' models that enable the retrospective identification of likely causes. In the field of Human Reliability Analysis (HRA) there is, however, a significant practical need for methods that can predict the occurrence of erroneous actions--qualitatively and quantitatively. The present experiment tested an approach for qualitative performance prediction based on the Cognitive Reliability and Error Analysis Method (CREAM). Predictions of possible erroneous actions were made for operators using different types of alarm systems. The data were collected as part of a large-scale experiment using professional nuclear power plant operators in a full scope simulator. The analysis showed that the predictions were correct in more than 70% of the cases, and also that the coverage of the predictions depended critically on the comprehensiveness of the preceding task analysis. PMID:10582035

  17. Uncertainty quantification and error analysis

    Energy Technology Data Exchange (ETDEWEB)

    Higdon, Dave M [Los Alamos National Laboratory; Anderson, Mark C [Los Alamos National Laboratory; Habib, Salman [Los Alamos National Laboratory; Klein, Richard [Los Alamos National Laboratory; Berliner, Mark [OHIO STATE UNIV.; Covey, Curt [LLNL; Ghattas, Omar [UNIV OF TEXAS; Graziani, Carlo [UNIV OF CHICAGO; Seager, Mark [LLNL; Sefcik, Joseph [LLNL; Stark, Philip [UC/BERKELEY; Stewart, James [SNL

    2010-01-01

    UQ studies all sources of error and uncertainty, including: systematic and stochastic measurement error; ignorance; limitations of theoretical models; limitations of numerical representations of those models; limitations on the accuracy and reliability of computations, approximations, and algorithms; and human error. A more precise definition for UQ is suggested below.

  18. Dose optimisation in single plane interstitial brachytherapy

    DEFF Research Database (Denmark)

    Tanderup, Kari; Hellebust, Taran Paulsen; Honoré, Henriette H;

    2006-01-01

    BACKGROUND AND PURPOSE: Brachytherapy dose distributions can be optimised       by modulation of source dwell times. In this study dose optimisation in       single planar interstitial implants was evaluated in order to quantify the       potential benefit in patients. MATERIAL AND METHODS: In 14...

  19. Severe rectal complications after prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Some investigators have reported severe rectal complications after brachytherapy. Due to the low number of such events, their relationship to dosimetric parameters has not been well characterized. Methods and materials: A total of 3126 patients were treated with low dose rate brachytherapy from 1998 through 2010. 2464 had implant alone, and 313 had implant preceded by 44–46 Gy supplemental external beam radiation (EBRT). Post-implant dosimetry was based on a CT scan obtained on the day of implant, generally within 30 min of the procedure. Every patient’s record was reviewed for occurrence of rectal complications. Results: Eight of 2464 patients (0.32%) treated with brachytherapy alone developed a radiation-related rectal fistula. Average prostatic and rectal dose parameters were moderately higher for fistula patients than for patients without a severe rectal complication. For instance, the average R100 was 1.2 ± 0.75 cc for fistula patients, versus 0.37 ± 0.88 cc for non-fistula patients. However, the fistula patients’ values were well within the range of values for patients without a rectal complication. Four patients had some attempt at repair or reconstruction, but long-term functional outcomes were not favorable. Conclusions: Rectal fistulas are a very uncommon potential complication of prostate brachytherapy, which can occur even in the setting of acceptable day 0 rectal doses. Their occurrence is not easily explained by standard dosimetric or clinical factors

  20. Early voiding dysfunction associated with prostate brachytherapy.

    Science.gov (United States)

    Wagner; Nag; Young; Bahnson

    2000-12-15

    Introduction: Transperineal prostate brachytherapy is gaining popularity as a treatment for clinically localized carcinoma of the prostate. Very little prospective data exists addressing the issue of complications associated with this procedure. We present an analysis of the early voiding dysfunction associated with prostate brachytherapy. Materials and Methods: Forty-six consecutive patients who underwent Palladium-103 (Pd-103) seed placement for clinically localized prostate carcinoma were evaluated prospectively for any morbidity associated with the procedure. Twenty-three patients completed an International Prostate Symptom Score (IPSS) questionnaire preoperatively, at their first postoperative visit, and at their second postoperative visit. The total IPSS, each of the seven individual components, and the "bother" score were evaluated separately for each visit, and statistical significance was determined. Results: Urinary retention occurred in 7/46 patients (15%). Of these, 5 were able to void spontaneously after catheter removal. One patient is maintained with a suprapubic tube, and one patient is currently on continuous intermittent catheterization. Baseline IPSS was 7.1 and this went to 20.0 at the first postoperative visit (p<0.001). By the second postoperative visit, the IPSS was 8.0. Conclusions: In our experience, prostate brachytherapy for localized carcinoma of the prostate is associated with a 15% catheterization rate and a significant increase in the IPSS (7.1 to 20.0). This increase in the IPSS seems to be self-limited. Patients need to be educated on these issues prior to prostate brachytherapy. PMID:11113369

  1. Dose calculation in brachytherapy with microcomputers

    International Nuclear Information System (INIS)

    The computer algorithms, that allow the calculation of brachytherapy doses and its graphic representation for implants, using programs developed for Pc microcomputers are presented. These algorithms allow to localized the sources in space, from their projection in radiographics images and trace isodose counter. (C.G.C.)

  2. Uncorrected refractive errors

    Directory of Open Access Journals (Sweden)

    Kovin S Naidoo

    2012-01-01

    Full Text Available Global estimates indicate that more than 2.3 billion people in the world suffer from poor vision due to refractive error; of which 670 million people are considered visually impaired because they do not have access to corrective treatment. Refractive errors, if uncorrected, results in an impaired quality of life for millions of people worldwide, irrespective of their age, sex and ethnicity. Over the past decade, a series of studies using a survey methodology, referred to as Refractive Error Study in Children (RESC, were performed in populations with different ethnic origins and cultural settings. These studies confirmed that the prevalence of uncorrected refractive errors is considerably high for children in low-and-middle-income countries. Furthermore, uncorrected refractive error has been noted to have extensive social and economic impacts, such as limiting educational and employment opportunities of economically active persons, healthy individuals and communities. The key public health challenges presented by uncorrected refractive errors, the leading cause of vision impairment across the world, require urgent attention. To address these issues, it is critical to focus on the development of human resources and sustainable methods of service delivery. This paper discusses three core pillars to addressing the challenges posed by uncorrected refractive errors: Human Resource (HR Development, Service Development and Social Entrepreneurship.

  3. CT-based interstitial HDR brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kolotas, C.; Baltas, D.; Zamboglou, N. [Staedtische Kliniken Offenbach (Germany). Strahlenklinik

    1999-09-01

    Purpose: Development, application and evaluation of a CT-guided implantation technique and a fully CT-based treatment planning procedure for brachytherapy. Methods and Materials: A brachytherapy procedure based on CT-guided implantation technique and CT-based treatment planning has been developed and clinical evaluated. For this purpose a software system (PROMETHEUS) for the 3D reconstruction of brachytherapy catheters and patient anatomy using only CT scans has been developed. An interface for the Nucletron PLATO BPS treatment planning system for optimization and calculation of dose distribution has been devised. The planning target volume(s) are defined as sets of points using contouring tools and are used for optimization of the 3D dose distribution. Dose-volume histogram based analysis of the dose distribution (COIN analysis) enables a clinically realistic evaluation of the brachytherapy application to be made. The CT-guided implantation of catheters and the CT-based treatment planning procedure has been performed for interstitial brachytherapy and for different tumor sites in 197 patients between 1996 and 1997. Results: The accuracy of the CT reconstruction was tested using first a quality assurance phantom and second, a simulated interstitial implant of 12 needles. These were compared with the results of reconstruction using radiographs. Both methods gave comparable results with regard to accuracy, but the CT based reconstruction was faster. Clinical feasibility was proved in pre-irradiated recurrences of brain tumors, in pretreated recurrences or metastatic disease, and in breast carcinomas. The tumor volumes treated were in the range 5.1 to 2,741 cm{sup 3}. Analysis of implant quality showed a slightly significant lower COIN value for the bone implants, but no differences with respect to the planning target volume. Conclusions: The Offenbach system, incorporating the PROMETHEUS software for interstitial HDR brachytherapy has proved to be extremely valuable

  4. In vivo dosimetry HDR brachytherapy prostate with source CO-60: Results of measures in a point urethra

    International Nuclear Information System (INIS)

    In this study we present and analyze the results of the in vivo dosimetry made a point of urethra with a group of 30 patients treated with brachytherapy prostate high rate with Co-60 source. Taking into account the uncertainties, the results and integration, globally evaluate this system DIV. This DIV system, due to its ease of calibration and use, and provides a relatively simple integration way to avoid serious errors in administering treatment. (Author)

  5. Comparison Analysis of MR Images Before and After External Beam Radiotherapy in Brachytherapy

    International Nuclear Information System (INIS)

    To analyze availability of MR images before and after external beam radiotherapy in brachytherapy, we will acquire MR images before and after external beam radiotherapy and compare the change of direction of uterine cavity and analyze the accuracy of applicator insertion. From January 2009 to December 2010, we compared MR images before and after external beam radiotherapy for uterine cervical cancer only with radical purpose treatment. MR images which was acquired after external beam radiotherapy has done with inserted status of CT/MR applicator. As a consequence, the tumor was markedly reduced after external beam radiotherapy. The change of anteflexion of uterus turned into retroflexion of the uterine cavity was 17.1%. The case of wrong insertion of tandem include direction or length was 14.3%. According to MR images taken after external beam radiotherapy, we recognized not only reduced the tumor volume but the marked change of exact direction or length of the uterine cavity. So the confirmation of accurate insertion based on MR images before brachytherapy could be very helpful for optimal brachytherapy treatment planning with reduced applicator insertion errors.

  6. Langzeitergebnisse bei Aderhautmelanom nach 106Ruthenium-Brachytherapie

    OpenAIRE

    Krause, Nona

    2015-01-01

    Introduction: 106Ruthenium-brachytherapy (106Ru-brachytherapy) is an established therapy for small and medium-sized uveal melanomas. The aim of this study was to examine the long-time results in regard to recurrence rate, complication rate, ocular preservation, metastasis rate and survival with malignant uveal and ciliary body melanoma, as well as relevant prognosis factors, subsequent to 106Ru-brachytherapy. Methodology: In this retrospective study of all cases with uveal or with ciliary ...

  7. Prostate cancer brachytherapy; Braquiterapia de cancer de prostata

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Carlos Eduardo Vita; Silva, Joao L. F. [Hospital Sirio Libanes, Sao Paulo, SP (Brazil). Centro de Oncologia. Dep. de Radioterapia; Srougi, Miguel; Nesrallah, Adriano [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina (EPM). Disciplina de Urologia]. E-mail: cevitabr@mandic.com.br

    1999-07-01

    The transperineal brachytherapy with {sup 125}I/Pd{sup 103} seed implantation guided by transurethral ultrasound must be presented as therapeutical option of low urinary morbidity in patients with localized prostate cancer. The combined clinical staging - including Gleason and initial PSA - must be encouraged, for definition of a group of low risk and indication of exclusive brachytherapy. Random prospective studies are necessary in order to define the best role of brachytherapy, surgery and external beam radiation therapy.

  8. Low dose rate Ir-192 interstitial brachytherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Oki, Yosuke; Dokiya, Takushi; Yorozu, Atsunori; Suzuki, Takayuki; Saito, Shiro; Monma, Tetsuo; Ohki, Takahiro [National Tokyo Medical Center (Japan); Murai, Masaru; Kubo, Atsushi

    2000-04-01

    From December 1997 through January 1999, fifteen prostatic cancer patients were treated with low dose rate Ir-192 interstitial brachytherapy using TRUS and perineal template guidance without external radiotherapy. Up to now, as no apparent side effects were found, the safety of this treatment is suggested. In the future, in order to treat prostatic cancer patients with interstitial brachytherapy using I-125 or Pd-103, more investigation for this low dose rate Ir-192 interstitial brachytherapy is needed. (author)

  9. Effective use of pre-job briefing as tool for the prevention of human error; Effektive Nutzung der Arbeitsvorbesprechung als Werkzeug zur Vermeidung von Fehlhandlungen

    Energy Technology Data Exchange (ETDEWEB)

    Schlump, Ansgar [KLE GmbH, Lingen (Germany). Kernkraftwerk Emsland

    2015-06-15

    There is a fundamental demand to minimise the risks for workers and facilities while executing maintenance work. To ensure that facilities are secure and reliable, any deviation from normal operation behaviour has to be avoided. Accurate planning is the basis for minimising mistakes and making work more secure. All workers involved should understand how the work should be done and what is expected to avoid human errors. Especially in nuclear power plants, the human performance tools (HPT) have proved to be an effective instrument to minimise human errors. These human performance tools consist of numerous different tools that complement each other (e.g. pre-job briefing). The safety culture of the plants is also characterised by these tools. The choice of using the right HP-Tool is often a difficult task for the work planer. On the one hand, he wants to avoid mistakes during the execution of work but on the other hand he does not want to irritate the workers with unnecessary requirements. The proposed concept uses a simple risk analysis to take into account the complexity of the task, the experience of the past and the consequences of failure in to account. One main result of this risk analysis is a recommendation of the detailing of the pre-job briefing, to reduce the risks for the involved staff to a minimum.

  10. In-phantom dosimetric measurements as quality control for brachytherapy. System check and constancy check

    International Nuclear Information System (INIS)

    In brachytherapy dosimetric measurements are difficult due to the inherent dose-inhomogeneities. Typically in routine clinical practice only the nominal dose rate is determined for computer controlled afterloading systems. The region of interest lies close to the source when measuring the spatial dose distribution. In this region small errors in the positioning of the detector, and its finite size, lead to large measurement uncertainties that exacerbate the routine dosimetric control of the system in the clinic. The size of the measurement chamber, its energy dependence, and the directional dependence of the measurement apparatus are the factors which have a significant influence on dosimetry. Although ionisation chambers are relatively large, they are employed since similar chambers are commonly found on clinical brachytherapy units. The dose is determined using DIN 6800 [11] since DIN 6809-2 [12], which deals with dosimetry in brachytherapy, is antiquated and is currently in the process of revision. Further information regarding dosimetry for brachytherapy can be found in textbooks [1] and [2]. The measurements for this work were performed with a HDR (High-Dose-Rate) 192Ir source, type mHDR V2, and a Microselectron Afterloader V2 both from Nucletron/Elekta. In this work two dosimetric procedures are presented which, despite the aforemention difficulties, should assist in performing checks of the proper operation of the system. The first is a system check that measures the dose distribution along a line and is to be performed when first bringing the afterloader into operation, or after significant changes to the system. The other is a dosimetric constancy check, which with little effort can be performed monthly or weekly. It simultaneously verifies the positioning of the source at two positions, the functionality of the system clock and the automatic re-calculation of the source activity.

  11. Brachytherapy in the treatment of genitourinary rhabdomyosarcoma in children

    International Nuclear Information System (INIS)

    Brachytherapy has been widely used at the Institut Gustave Roussy since 1972 in pediatric oncology. In genitourinary rhabdomyosarcoma, because of its ballistic and physical characteristics, it represents the optimal treatment whenever irradiation is required and brachytherapy feasible. Between 1976 and 1998, 23 children with bladder or prostate rhabdomyosarcoma were treated with a protocol including brachytherapy, with five of them treated with a salvage brachytherapy. All but one brachytherapy was performed during the surgery. Among the 18 brachy-therapies performed as a first-line treatment, eight presented a tumoral evolution: five presented a local evolution, one a local and nodal evolution and two a nodal evolution. Brachytherapy allowed a conservative treatment among ten out of 11 children alive with no evidence of disease. Among the five patients with salvage brachytherapy, two presented a second recurrence. Sequelae were minimal, consisting of one grade I rectitis and one asymptomatic vesical and ureteral reflux. These results are consistent with the published data using more radical treatment. Brachytherapy can represent an alternative to radical surgery, when indications are clearly defined in bladder or prostate rhabdomyosarcoma. This type of treatment can be performed only integrated with other treatments, more particularly with surgery. This approach requires a close cooperation between the different specialists: pediatricians, surgeons and brachy-therapists. (authors)

  12. Implementation of High Dose Rate Brachytherapy in Limited Resource Settings

    International Nuclear Information System (INIS)

    Brachytherapy is an essential component of the curative treatment of cervical cancer, a disease with high incidence in many developing countries The IAEA supports the use of high dose rate brachytherapy for centres with a large number of patients with this disease. HDR brachytherapy is also used in other common cancers such as breast cancer, lung, oesophagus and prostate. This publication provides guidance to radiation oncologists, medical physicists and planners on establishing and operating a high dose rate brachytherapy unit with modern standards and presents the main issues to be addressed for its effective and safe operation

  13. Cost effective method of manual afterloading 192Ir brachytherapy

    International Nuclear Information System (INIS)

    Full text: In radiotherapy, brachytherapy mode of treatment has equal importance like the external beam radiotherapy. In our hospital we have manual afterloading 137Cs kit supplied by BRIT for intracavitary treatment of carcinoma cervix and vaginal cases. In July 1999, we also started afterloading 192Ir brachytherapy. For a hospital like ours, where funds are minimal, it is impossible to procure remote afterloading brachytherapy unit, which is very costly. So we have developed the cost-effective 192Ir manual brachytherapy and so far we have done 60 cases which include intraluminal and interstitial cases

  14. A comparison of complications between ultrasound-guided prostate brachytherapy and open prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Prostate brachytherapy has reemerged during the 1990s as a treatment for clinically localized prostate cancer. The renewed popularity of prostate brachytherapy is largely due to the use of transrectal ultrasound of the prostate, which allows for more accurate isotope placement within the prostate when compared to the open approach. The present study investigates whether this improved cancer control is at the expense of increased morbidity by comparing the morbidity after transrectal ultrasound-guided prostate brachytherapy to the morbidity after prostate brachytherapy performed via an open approach. Methods and Materials: All men in the Medicare population who underwent prostate brachytherapy in the year 1991 were identified. These men were further stratified into those men who underwent prostate brachytherapy via an open approach and the men who underwent prostate brachytherapy with ultrasound guidance. All subsequent inpatient, outpatient, and physician (Part B) Medicare claims for these men from the years 1991-1993 were then analyzed to determine outcomes. Results: In the year 1991, 2124 men in the Medicare population underwent prostate brachytherapy. An open approach was used in 715 men (33.7%), and ultrasound guidance was used in 1409 men (66.3%). Mean age for both cohorts was 73.7 years with a range of 50.7-92.8 years for the ultrasound group and 60.6-92.1 years for the open group. A surgical procedure for the relief of bladder outlet obstruction was performed in 122 men (8.6%) in the ultrasound group and in 54 men (7.6%) in the open group. An artificial urinary sphincter was placed in 2 men (0.14%) in the ultrasound group and in 2 men (0.28%) in the open group. A penile prosthesis was implanted in 10 men (0.71%) in the ultrasound group and in 4 men (0.56%) in the open group. A diagnosis code for urinary incontinence was carried by 95 men (6.7%) in the ultrasound group and by 45 men (6.3%) in the open group. A diagnosis code for erectile dysfunction

  15. Regeneration in cervix cancer after 252Cf neutron brachytherapy

    International Nuclear Information System (INIS)

    Regeneration of clonogens in human cervical cancer was assessed by the pathological evaluation of the hysterectomy specimen after intracavitary 252Cf neutron brachytherapy implants separated by varying time intervals followed by extrafascial hysterectomy. In this study, patients with bulky/barrel shaped Stage IB cervical cancers received 252Cf implants plus approximately 45 Gy of whole pelvis linear accelerator radiotherapy in approximately 25 fractions in 5 weeks followed by hysterectomy 4-6 weeks after radiotherapy. The specimens were studied grossly and microscopically for residual tumor. It was found that the fraction of positive specimens increased with elapsed time interval between implants. These findings support the hypothesis that there is repopulation of surviving clonogens with increased time interval between the implants. The observation also supports current concerns that rapid depopulation of tumor can lead to rapid repopulation, that is, rapid shrinkage of tumor can alter the physiological environment such that clonogens can rapidly regenerate

  16. Development of a Brachytherapy Software Nomogram Equivalent

    International Nuclear Information System (INIS)

    The main objective of this project is developing a software nomogram equivalent. A nomogram is a graph typically comprised of three parallel lines. Each of the lines is graduated for a different variable, often in a non-linear scale. The lines are oriented in such a manner that if a straight line is drawn connecting two of the three variables, the value of the third variable is uniquely determined by the intersection of the connecting line and the graduated line of the third variable. The value of the third variable is determined by reading the graduated scale at the point of intersection. A nomogram as applied in brachytherapy is used for determining the required amount of radioactive material to be implanted in a diseased site. A typical brachytherapy nomogram relates the average dimension of a site, the air kerma strength per source and the number of sources required for yielding a therapeutic radiation dose to the site. More sophisticated nomograms also provide scales for recommending source and needle spacings. For decades the nomogram has been clinically employed as a brachytherapy treatment planning tool. Imaging modalities such as CT and ultrasound ushered in modern image-based brachytherapy treatment planning. These modern imaging techniques dramatically advanced the state of the art of brachytherapy, often obviating the use of nomograms. Although the routine use of nomograms has decreased, there are clinical situations where nomograms still prove useful for brachytherapy treatment planning. Often times the dimensions of a tumor or tumor bed are not known prior to surgery and delineated images of the site are not available. In such situations the tumor dimensions can be measured in the OR and a nomogram applied for rapid treatment planning. By definition a nomogram is a graphical tool, which is fixed and cannot be modified. Differences of opinion and treatment philosophies exist among physicians and institutions. These varying approaches can lead to

  17. Refractive Errors

    Science.gov (United States)

    ... the eye keeps you from focusing well. The cause could be the length of the eyeball (longer or shorter), changes in the shape of the cornea, or aging of the lens. Four common refractive errors are Myopia, or nearsightedness - clear vision close up ...

  18. Human subthalamic nucleus-medial frontal cortex theta phase coherence is involved in conflict and error related cortical monitoring.

    Science.gov (United States)

    Zavala, Baltazar; Tan, Huiling; Ashkan, Keyoumars; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Zaghloul, Kareem; Brown, Peter

    2016-08-15

    The medial prefrontal cortex (mPFC) is thought to control the shift from automatic to controlled action selection when conflict is present or when mistakes have been recently committed. Growing evidence suggests that this process involves frequency specific communication in the theta (4-8Hz) band between the mPFC and the subthalamic nucleus (STN), which is the main target of deep brain stimulation (DBS) for Parkinson's disease. Key in this hypothesis is the finding that DBS can lead to impulsivity by disrupting the correlation between higher mPFC oscillations and slower reaction times during conflict. In order to test whether theta band coherence between the mPFC and the STN underlies adjustments to conflict and to errors, we simultaneously recorded mPFC and STN electrophysiological activity while DBS patients performed an arrowed flanker task. These recordings revealed higher theta phase coherence between the two sites during the high conflict trials relative to the low conflict trials. These differences were observed soon after conflicting arrows were displayed, but before a response was executed. Furthermore, trials that occurred after an error was committed showed higher phase coherence relative to trials that followed a correct trial, suggesting that mPFC-STN connectivity may also play a role in error related adjustments in behavior. Interestingly, the phase coherence we observed occurred before increases in theta power, implying that the theta phase and power may influence behavior at separate times during cortical monitoring. Finally, we showed that pre-stimulus differences in STN theta power were related to the reaction time on a given trial, which may help adjust behavior based on the probability of observing conflict during a task. PMID:27181763

  19. Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Data manual, Part 2: Human Error Probability (HEP) Data. Volume 5, Revision 4

    International Nuclear Information System (INIS)

    This data manual contains a hard copy of the information in the Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) Version 3.5 database, which is sponsored by the US Nuclear Regulatory Commission. NUCLARR was designed as a tool for risk analysis. Many of the nuclear reactors in the US and several outside the US are represented in the NUCLARR database. NUCLARR includes both human error probability estimates for workers at the plants and hardware failure data for nuclear reactor equipment. Aggregations of these data yield valuable reliability estimates for probabilistic risk assessments and human reliability analyses. The data manual is organized to permit manual searches of the information if the computerized version is not available. Originally, the manual was published in three parts. In this revision the introductory material located in the original Part 1 has been incorporated into the text of Parts 2 and 3. The user can now find introductory material either in the original Part 1, or in Parts 2 and 3 as revised. Part 2 contains the human error probability data, and Part 3, the hardware component reliability data

  20. Human error and crew resource management failures in Naval aviation mishaps: a review of U.S. Naval Safety Center data, 1990-96.

    Science.gov (United States)

    Wiegmann, D A; Shappell, S A

    1999-12-01

    The present study examined the role of human error and crew-resource management (CRM) failures in U.S. Naval aviation mishaps. All tactical jet (TACAIR) and rotary wing Class A flight mishaps between fiscal years 1990-1996 were reviewed. Results indicated that over 75% of both TACAIR and rotary wing mishaps were attributable, at least in part, to some form of human error of which 70% were associated with aircrew human factors. Of these aircrew-related mishaps, approximately 56% involved at least one CRM failure. These percentages are very similar to those observed prior to the implementation of aircrew coordination training (ACT) in the fleet, suggesting that the initial benefits of the program have not persisted and that CRM failures continue to plague Naval aviation. Closer examination of these CRM-related mishaps suggest that the type of flight operations (preflight, routine, emergency) do play a role in the etiology of CRM failures. A larger percentage of CRM failures occurred during non-routine or extremis flight situations when TACAIR mishaps were considered. In contrast, a larger percentage of rotary wing CRM mishaps involved failures that occurred during routine flight operations. These findings illustrate the complex etiology of CRM failures within Naval aviation and support the need for ACT programs tailored to the unique problems faced by specific communities in the fleet. PMID:10596766

  1. Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Data manual. Part 2: Human error probability (HEP) data; Volume 5, Revision 4

    Energy Technology Data Exchange (ETDEWEB)

    Reece, W.J.; Gilbert, B.G.; Richards, R.E. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

    1994-09-01

    This data manual contains a hard copy of the information in the Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) Version 3.5 database, which is sponsored by the US Nuclear Regulatory Commission. NUCLARR was designed as a tool for risk analysis. Many of the nuclear reactors in the US and several outside the US are represented in the NUCLARR database. NUCLARR includes both human error probability estimates for workers at the plants and hardware failure data for nuclear reactor equipment. Aggregations of these data yield valuable reliability estimates for probabilistic risk assessments and human reliability analyses. The data manual is organized to permit manual searches of the information if the computerized version is not available. Originally, the manual was published in three parts. In this revision the introductory material located in the original Part 1 has been incorporated into the text of Parts 2 and 3. The user can now find introductory material either in the original Part 1, or in Parts 2 and 3 as revised. Part 2 contains the human error probability data, and Part 3, the hardware component reliability data.

  2. Management of a HDR brachytherapy system in the Hospital Juarez of Mexico

    International Nuclear Information System (INIS)

    Full text: In the Hospital Juarez of Mexico, it is carried out a project to implement a Brachytherapy system with high dose rate (HDR) through a Management quality program. In our work center this treatment modality in patients with cervicouterine cancer is used (CaCu), and constantly it is necessary to carry out improvements in the procedures, with the purpose of optimizing them and in consequence to complete the principles of the Radiological Protection, guaranteeing this way, an attention with the quality and safety, such that allow to diminish the risks to the patients and to assure that the received dose in critical organs it finds inside the permitted therapeutic limits, without commit the radiosensitive response of healthy organs. In this work an analysis of the implementation of this system is presented, detailing the procedures so much in the technological infrastructure like human and indicating the necessary technical and operative requirements to reach an adequate practice in HDR brachytherapy. (Author)

  3. 10 CFR 35.400 - Use of sources for manual brachytherapy.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Use of sources for manual brachytherapy. 35.400 Section 35.400 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.400 Use of sources for manual brachytherapy. A licensee shall use only brachytherapy sources...

  4. Radiochromic dye film studies for brachytherapy applications.

    Science.gov (United States)

    Martínez-Dávalos, A; Rodríguez-Villafuerte, M; Díaz-Perches, R; Arzamendi-Pérez, S

    2002-01-01

    Commercial radiochromic dye films have been used in recent years to quantify absorbed dose in several medical applications. In this study we present the characterisation of the GafChromic MD-55-2 dye film, a double sensitive layer film suitable for photon irradiation in brachytherapy applications. Dose measurements were carried out with a low dose rate 137Cs brachytherapy source, which produces very steep dose gradients in its vicinity, and therefore requires the capability of producing high spatial resolution isodose curves. Quantification of the dose rate in water per unit air kerma strength was obtained using a high-resolution transmission commercial scanner (Agfa DuoScan T1200 with the capability of digitising up to 600 x 1200 pixels per inch using 36 bits per pixel, together with optical density measurements. The Monte Carlo calculations and experimental measurements compared well in the 0-50 Gy dose interval used in this study. PMID:12382798

  5. Radiochromic dye film studies for brachytherapy applications

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Davalos, A.; Rodriguez-Villafuerte, M.; Diaz-Perches, R.; Arzamendi-Perez, S

    2002-07-01

    Commercial radiochromic dye films have been used in recent years to quantify absorbed dose in several medical applications. In this study we present the characterisation of the GafChromic MD-55-2 dye film, a double sensitive layer film suitable for photon irradiation in brachytherapy applications. Dose measurements were carried out with a low dose rate {sup 137}Cs brachytherapy source, which produces very steep dose gradients in its vicinity, and therefore requires the capability of producing high spatial resolution isodose curves. Quantification of the dose rate in water per unit air kerma strength was obtained using a high-resolution transmission commercial scanner (Agfa DuoScan T1200) with the capability of digitising up to 600 x 1200 pixels per inch using 36 bits per pixel, together with optical density measurements. The Monte Carlo calculations and experimental measurements compared well in the 0-50 Gy dose interval used in this study. (author)

  6. Radiochromic dye film studies for brachytherapy applications

    International Nuclear Information System (INIS)

    Commercial radiochromic dye films have been used in recent years to quantify absorbed dose in several medical applications. In this study we present the characterisation of the GafChromic MD-55-2 dye film, a double sensitive layer film suitable for photon irradiation in brachytherapy applications. Dose measurements were carried out with a low dose rate 137Cs brachytherapy source, which produces very steep dose gradients in its vicinity, and therefore requires the capability of producing high spatial resolution isodose curves. Quantification of the dose rate in water per unit air kerma strength was obtained using a high-resolution transmission commercial scanner (Agfa DuoScan T1200) with the capability of digitising up to 600 x 1200 pixels per inch using 36 bits per pixel, together with optical density measurements. The Monte Carlo calculations and experimental measurements compared well in the 0-50 Gy dose interval used in this study. (author)

  7. The evolution of brachytherapy treatment planning

    International Nuclear Information System (INIS)

    Brachytherapy is a mature treatment modality that has benefited from technological advances. Treatment planning has advanced from simple lookup tables to complex, computer-based dose-calculation algorithms. The current approach is based on the AAPM TG-43 formalism with recent advances in acquiring single-source dose distributions. However, this formalism has clinically relevant limitations for calculating patient dose. Dose-calculation algorithms are being developed based on Monte Carlo methods, collapsed cone, and solving the linear Boltzmann transport equation. In addition to improved dose-calculation tools, planning systems and brachytherapy treatment planning will account for material heterogeneities, scatter conditions, radiobiology, and image guidance. The AAPM, ESTRO, and other professional societies are working to coordinate clinical integration of these advancements. This Vision 20/20 article provides insight into these endeavors.

  8. The evolution of brachytherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, Mark J.; Venselaar, Jack L. M.; Beaulieu, Luc [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Department of Medical Physics, Instituut Verbeeten, P.O. Box 90120, 5000 LA Tilburg (Netherlands); Departement de Radio-Oncologie et Centre de Recherche en Cancerologie de l' Universite Laval, Centre Hospitalier Universitaire de Quebec, 11 Cote du Palais, Quebec, Quebec G1R 2J6 (Canada) and Departement de Physique, de Genie Physique et d' Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada)

    2009-06-15

    Brachytherapy is a mature treatment modality that has benefited from technological advances. Treatment planning has advanced from simple lookup tables to complex, computer-based dose-calculation algorithms. The current approach is based on the AAPM TG-43 formalism with recent advances in acquiring single-source dose distributions. However, this formalism has clinically relevant limitations for calculating patient dose. Dose-calculation algorithms are being developed based on Monte Carlo methods, collapsed cone, and solving the linear Boltzmann transport equation. In addition to improved dose-calculation tools, planning systems and brachytherapy treatment planning will account for material heterogeneities, scatter conditions, radiobiology, and image guidance. The AAPM, ESTRO, and other professional societies are working to coordinate clinical integration of these advancements. This Vision 20/20 article provides insight into these endeavors.

  9. Sexual function after permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To determine the incidence of potency preservation following permanent prostate brachytherapy and to evaluate the effect of multiple clinical and treatment parameters on penile erectile function. Materials and Methods: 425 patients underwent permanent prostate brachytherapy from April 1995 to October 1999. 209 patients who were potent prior to brachytherapy and currently not receiving hormonal manipulation were mailed an International Index of Erectile Function (IIEF) questionnaire with a pre-addressed stamped envelope. 180 patients completed and returned the questionnaire. Median patient follow-up was 39 months (range 18-74 months). Pre-implant erectile function was assigned using a three-tiered scoring system (2 = erections always or nearly always sufficient for vaginal penetration; 1 = erections sufficient for vaginal penetration but considered suboptimal; 0 = the inability to obtain erections and/or erections inadequate for vaginal penetration). Post-implant potency was defined as an IIEF score >11. Clinical parameters evaluated for sexual function included patient age, clinical T stage, elapsed time since implantation, hypertension, diabetes mellitus, and tobacco consumption. Evaluated treatment parameters included the utilization of neoadjuvant hormonal manipulation and the choice of isotope. The efficacy of sildenafil citrate in brachytherapy induced erectile dysfunction (ED) was also evaluated. Results: A pre-treatment erectile function score of 2 and 1 were assigned to 126 and 54 patients respectively. With 6 year follow up, 39% of patients maintained potency following prostate brachytherapy with a plateau on the curve. Post-implant preservation of potency (IIEF>11) correlated with pre-implant erectile function (50% versus 14% for pre-implant scores of 2 and 1 respectively, p≤0.0001), patient age (56%, 38%, and 23% for patients <60 years of age, 60-69 years of age, and ≥70 years of age respectively, p=0.012) and a history of diabetes mellitus

  10. American Brachytherapy Society (ABS) recommendations for transperineal permanent brachytherapy of prostate cancer

    International Nuclear Information System (INIS)

    Purpose/Objective: To develop and disseminate the American Brachytherapy Society (ABS) recommendations for the clinical quality assurance and guidelines of permanent transperineal prostate brachytherapy with 125I or 103Pd. Methods and Materials: The ABS formed a committee of experts in prostate brachytherapy to develop consensus guidelines through a critical analysis of published data supplemented by their clinical experience. The recommendations of the panels were reviewed and approved by the Board of Directors of the ABS. Results: Patients with high probability of organ-confined disease are appropriately treated with brachytherapy alone. Brachytherapy candidates with a significant risk of extraprostatic extension should be treated with supplemental external beam radiation therapy (EBRT). Patient selection guidelines were developed. Dosimetric planning of the implant should be carried out for all patients before seed insertion. A modified peripheral loading is preferred. The AAPM TG-43 recommendations requiring a change in prescription dose for 125I sources should be universally implemented. The recommended prescription doses for monotherapy are 145 Gy for 125I and 115-120 Gy for 103Pd. The corresponding boost doses (after 40-50 Gy EBRT) are 100-110 Gy and 80-90 Gy, respectively. Clinical evidence to guide selection of radionuclide (103Pd or 125I) is lacking. Post implant dosimetry and evaluation must be performed on all patients. It is suggested that the dose that covers 90% (D90) and 100% (D100) of the prostate volume and the percentage of the prostate volume receiving the prescribed dose (V100) be obtained from a dose-volume histogram (DVH) and reported. Conclusion: Guidelines for appropriate patient selection, dose reporting, and improved quality of permanent prostate brachytherapy are presented. These broad recommendations are intended to be technical and advisory in nature, but the ultimate responsibility for the medical decisions rests with the treating

  11. Microdosimetric evaluation of relative biological effectiveness for 103PD, 125I, 241AM, and 192IR brachytherapy sources

    International Nuclear Information System (INIS)

    Purpose: To determine the microdosimetric-derived relative biological effectiveness (RBE) of 103Pd, 125I, 241Am, and 192Ir brachytherapy sources at low doses and/or low dose rates. Methods and Materials: The Theory of Dual Radiation Action can be used to predict expected RBE values based on the spatial distribution of energy deposition at microscopic levels from these sources. Single-event lineal energy spectra for these isotopes have been obtained both experimentally and theoretically. A grid-defined wall-less proportional counter was used to measure the lineal energy distributions. Unlike conventional Rossi proportional counters, the counter used in these measurements has a conducting nylon fiber as the central collecting anode and has no metal parts. Thus, the Z-dependence of the photoelectric effect is eliminated as a source of measurement error. Single-event spectra for these brachytherapy sources have been also calculated by: (a) the Monte Carlo code MCNP to generate the electron slowing down spectrum, (b) transport of monoenergetic electron tracks, event by event, with our Monte Carlo code DELTA, (c) using the concept of associated volume to obtain the lineal energy distribution f(y) for each monoenergetic electron, and (d) obtaining the composite lineal energy spectrum for a given brachytherapy source based on the electron spectrum calculated at step (a). Results: Relative to 60Co, the RBE values obtained from this study are: 2.3 for 103Pd, 2.1 for 125I, 2.1 for 241Am, and 1.3 for 192Ir. Conclusions: These values are consistent with available data from in vitro cell survival experiments. We suggest that, at least for these brachytherapy sources, microdosimetry may be used as a credible alternative to time-consuming (and often uncertain) radiobiological experiments to obtain information on radition quality and make reliable predictions of RBE in low dose rate brachytherapy

  12. Sci—Fri PM: Topics — 08: The Role and Benefits of Electromagnetic Needle-Tracking Technologies in Brachytherapy

    International Nuclear Information System (INIS)

    In modern brachytherapy, application of large doses of ionizing radiation in a limited number of fractions is frequent. Furthermore, as with any surgical procedures, brachytherapy is subject to learning curve effects. In this context, there could be advantages of integrating real-time tracking of needles/catheters to existing protocols given the recent prominent advances in tracking technologies. In this work, we review the use of an electromagnetic tracking system (EMTS) based on the second generation Aurora® Planar Field Generator (Northern Digital Inc) and custom design needles (Philips Healthcare) for brachytherapy applications. The position and orientation information is obtained from 5 degrees of freedom sensors. Basic system performance characterization is performed in well-controlled conditions to establish accuracy and reproducibility as well as potential interference from standard brachytherapy equipment. The results show that sensor locations can be tracked to within 0.04mm (la) when located within 26cm of the generator. Orientation accuracy of the needle remained within ±1° in the same region, but rose quickly at larger distances. The errors on position and orientation strongly dependent the sensor position in the characterization volume (500×500×500mm3). The presence of an ultrasound probe was shown to have negligible effects on tracking accuracy. The use of EMTS for automatic catheter/applicator reconstruction was also explored. Reconstruction time was less than 10 sec/channel and tips identification was within 0.69±0.29mm of the reference values. Finally, we demonstrate that hollow needle designs with special EM adaptation also allow for real-time seed drop position estimation. In phantom experiments showed that drop positions were on average within 1.6±0.9mm of the reference position measured from μCT. Altogether, EMTS offer promising benefits in a wide range of brachytherapy applications

  13. Sci—Fri PM: Topics — 08: The Role and Benefits of Electromagnetic Needle-Tracking Technologies in Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Beaulieu, L.; Racine, E.; Boutaleb, S.; Filion, O. [Département de Radio-Oncologie et Centre de Recherche du CHU de Québec, CHU de Québec, Québec (Québec), and Département de Physique, de Génie Physique et d' Optique et Centre de recherche en sur le Cancer, Université Laval, Québec (Québec) (Canada); Poulin, E.; Hautvast, G. [Biomedical Systems, Philips Group Innovation, High Tech Campus 34 (HTC 34), Eindhoven (Netherlands); Binnekamp, D. [Integrated Clinical Solutions and Marketing, Philips Healthcare, Veenpluis 4-6, Best (Netherlands)

    2014-08-15

    In modern brachytherapy, application of large doses of ionizing radiation in a limited number of fractions is frequent. Furthermore, as with any surgical procedures, brachytherapy is subject to learning curve effects. In this context, there could be advantages of integrating real-time tracking of needles/catheters to existing protocols given the recent prominent advances in tracking technologies. In this work, we review the use of an electromagnetic tracking system (EMTS) based on the second generation Aurora® Planar Field Generator (Northern Digital Inc) and custom design needles (Philips Healthcare) for brachytherapy applications. The position and orientation information is obtained from 5 degrees of freedom sensors. Basic system performance characterization is performed in well-controlled conditions to establish accuracy and reproducibility as well as potential interference from standard brachytherapy equipment. The results show that sensor locations can be tracked to within 0.04mm (la) when located within 26cm of the generator. Orientation accuracy of the needle remained within ±1° in the same region, but rose quickly at larger distances. The errors on position and orientation strongly dependent the sensor position in the characterization volume (500×500×500mm{sup 3}). The presence of an ultrasound probe was shown to have negligible effects on tracking accuracy. The use of EMTS for automatic catheter/applicator reconstruction was also explored. Reconstruction time was less than 10 sec/channel and tips identification was within 0.69±0.29mm of the reference values. Finally, we demonstrate that hollow needle designs with special EM adaptation also allow for real-time seed drop position estimation. In phantom experiments showed that drop positions were on average within 1.6±0.9mm of the reference position measured from μCT. Altogether, EMTS offer promising benefits in a wide range of brachytherapy applications.

  14. Evolution of dose distribution calculations in brachytherapy

    International Nuclear Information System (INIS)

    In this report the evolution of dose distribution calculations is revised in detail, considering the simplest case (a point source in free space) and the more complex situation of a real encapsulated line source embedded in a scattering medium. The most recent formalism to perform the dosimetry of interstitial brachytherapy sources is presented, where measured or measurable dose rates from actual sources in a tissue equivalent phantom are required as input data

  15. Brachytherapy in treatment of vaginal cancer

    OpenAIRE

    A. D. Kaprin; V. N. Galkin; S. A. Ivanov; V. A. Solodkiy; V. A. Titova

    2016-01-01

    Characteristics of diagnosis and treatment of different types of primary vaginal cancer are highlighted, the role and place of brachytherapy as independent method or combined treatment modality for this pathology is shown in the review. Epidemiological data on incidence of vaginal cancer in Russia are represented, presumptive mechanisms for development of the disease, risk factors, histological types, features of the course, clinical presentation, diagnostic algorithm are described. Treatment...

  16. Photoacoustic imaging of prostate brachytherapy seeds

    OpenAIRE

    Su, Jimmy L.; Bouchard, Richard R.; Karpiouk, Andrei B.; Hazle, John D.; Emelianov, Stanislav Y.

    2011-01-01

    Brachytherapy seed therapy is an increasingly common way to treat prostate cancer through localized radiation. The current standard of care relies on transrectal ultrasound (TRUS) for imaging guidance during the seed placement procedure. As visualization of individual metallic seeds tends to be difficult or inaccurate under TRUS guidance, guide needles are generally tracked to infer seed placement. In an effort to improve seed visualization and placement accuracy, the use of photoacoustic (PA...

  17. Procedures for calibration of brachytherapy sources

    International Nuclear Information System (INIS)

    Brachytherapy source strength verification is a responsibility of the user of these source, in fact of the Medical Physicists in charge of this issue in a Radiotherapy Service. The calibration procedures in the users conditions are shown. Specifics methods for source strength determination are recommended, both for High Dose Rate (HDR) sources with Remote Afterloading equipment and for Low Dose Rate sources. The The results of the calibration of HDR Remote After loaders are indicated

  18. Erectile Function Durability Following Permanent Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To evaluate long-term changes in erectile function following prostate brachytherapy. Methods and Materials: This study included 226 patients with prostate cancer and preimplant erectile function assessed by the International Index of Erectile Function-6 (IIEF-6) who underwent brachytherapy in two prospective randomized trials between February 2001 and January 2003. Median follow-up was 6.4 years. Pre- and postbrachytherapy potency was defined as IIEF-6 ≥ 13 without pharmacologic or mechanical support. The relationship among clinical, treatment, and dosimetric parameters and erectile function was examined. Results: The 7-year actuarial rate of potency preservation was 55.6% with median postimplant IIEF of 22 in potent patients. Potent patients were statistically younger (p = 0.014), had a higher preimplant IIEF (p < 0.001), were less likely to be diabetic (p = 0.002), and were more likely to report nocturnal erections (p = 0.008). Potency preservation in men with baseline IIEF scores of 29-30, 24-28, 18-23, and 13-17 were 75.5% vs. 73.6%, 51.7% vs. 44.8%, 48.0% vs. 40.0%, and 23.5% vs. 23.5% in 2004 vs. 2008. In multivariate Cox regression analysis, preimplant IIEF, hypertension, diabetes, prostate size, and brachytherapy dose to proximal penis strongly predicted for potency preservation. Impact of proximal penile dose was most pronounced for men with IIEF of 18-23 and aged 60-69. A significant minority of men who developed postimplant impotence ultimately regained erectile function. Conclusion: Potency preservation and median IIEF scores following brachytherapy are durable. Thoughtful dose sparing of proximal penile structures and early penile rehabilitation may further improve these results.

  19. Magnetite nanoparticles for nonradionuclide brachytherapy1

    OpenAIRE

    Safronov, Victor; Sozontov, Evgeny; Polikarpov, Mikhail

    2015-01-01

    Magnetite nanoparticles possess several properties that can make them useful for targeted delivery of radiation to tumors for the purpose of brachytherapy. Such particles are biodegradable and magnetic and can emit secondary radiation when irradiated by an external source. In this work, the dose distribution around a magnetite particle of 10 nm diameter being irradiated by monochromatic X-rays with energies in the range 4–60 keV is calculated.

  20. Dosimetry in high dose rate endoluminal brachytherapy

    International Nuclear Information System (INIS)

    In endoluminal brachytherapy for the tracheobronchial tree, esophagus, and bile duct, a reference point for dose calculation has been often settled at 1 cm outside from the middle of source travel path. In the current study, a change in the ratio of the reference point dose on the convex to concave side (Dq/Dp) was calculated, provided the source travel path bends as is the case in most endoluminal brachytherapies. Point source was presumed to move stepwise at 1 cm interval from 4 to 13 locations. Retention time at each location was calculated by personal computer so as to deliver equal dose at 1 cm from the linear travel path. With the retention time remaining constant, the change of Dq/Dp was assessed by bending the source travel path. Results indicated that the length of the source travel path and radius of its curve influenced the pattern of change in Dq/Dp. Therefore, it was concluded that the difference in reference dose on the convex and concave side of the curved path is not negligible under certain conditions in endoluminal brachytherapy. In order to maintain the ratio more than 0.9, relatively greater radius was required when the source travel path was decreased. (author)

  1. Paraspinal tumors: Techniques and results of brachytherapy

    International Nuclear Information System (INIS)

    Because of their proximity to nerve roots and the spinal cord, it is frequently difficult to achieve complete resection of paraspinal tumors. We have used brachytherapy in an attempt to prevent local recurrence and its associated neurological sequelae. This report analyzes our experience with 35 patients to determine the feasibility, optimal techniques, and efficacy of this approach. The tumor types were non small-cell lung cancer (18), sarcomas (9), and other tumor types (8). Temporary, single plane implants using Ir-192 (median minimum peripheral dose 3000 cGy) were used in 21 patients, and permanent I-125 implants were used in 14 cases (median matched peripheral dose 12,500 cGy). Local control was achieved in 51% (18/35). However, local control was poor when lung cancers were implanted and in cases where the dura was exposed. Radiation myelitis did not occur despite the combined effects of previous external beam radiotherapy (N = 21) and brachytherapy. Our experience demonstrates that combined surgery and paraspinal brachytherapy can be performed with acceptable toxicity and is reasonably effective in preventing local relapse and its neurologic sequelae, particularly for tumors other than lung cancers

  2. Brachytherapy treatment with high dose rate

    International Nuclear Information System (INIS)

    Retrospectively analyze results and prognostic factors of cervical cancer patients treated with radio concomitant cisplatin-based chemotherapy, radiation therapy combined modality. Methods: From January 2003 to December 2007, 198 patients with invasive cervical cancer were treated at the Oncology Department of Hospital Robau Celestino Hernandez (brachytherapy performed at INOR). The most common age group was 31 to 40 years. The histology in squamous cell carcinoma accounted for 84.3% of cases. The treatment consisted of external pelvic irradiation and vaginal brachytherapy, high dose rate. Concomitant chemotherapy consisted of cisplatin 40 mg/m2 weekly with a maximum of 70 mg for 5 weeks. Results: 66.2% of patients completed 5 cycles of chemotherapy. The median overall survival was 39 months, overall survival, disease-free survival and survival free of locoregional recurrence at 5 years of 78%, 76% and 78.6% respectively .. We found that clinical stage, histological type (adenocarcinoma worst outcome) were statistically related to level of response. Conclusions: Treatment with external pelvic radiation, brachytherapy and concurrent weekly cisplatin in patients with stage IIIB cervical cancer is feasible in the Chilean public health system, well tolerated and results comparable to international literature. (Author)

  3. Radioactive seed immobilization techniques for interstitial brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yan, K.; Podder, T.; Buzurovic, I.; Hu, Y.; Dicker, A.; Valicenti, R.; Yu, Y. [Thomas Jefferson University, Department of Radiation Oncology, Philadelphia, PA (United States); Messing, E. [University of Rochester, Departments of Urology and Surgery, Rochester, NY (United States); Rubens, D. [University of Rochester, Departments of Imaging Science and Surgery, Rochester, NY (United States); Sarkar, N. [Vanderbilt University, Department of Mechanical Engineering, Nashville, TN (United States); Ng, W. [Nangyang Technical University, School of Mechanical and Aerospace Engineering, Singapore (Singapore)

    2008-06-15

    In prostate brachytherapy, seeds can detach from their deposited sites and move locally in the pelvis or migrate to distant sites including the pulmonary and cardiac regions. Undesirable consequences of seed migration include inadequate dose coverage of the prostate and tissue irradiation effects at the site of migration. Thus, it is clinically important to develop seed immobilization techniques. We first analyze the possible causes for seed movement, and propose three potential techniques for seed immobilization: (1) surgical glue, (2) laser coagulation and (3) diathermy coagulation. The feasibility of each method is explored. Experiments were carried out using fresh bovine livers to investigate the efficacy of seed immobilization using surgical glue. Results have shown that the surgical glue can effectively immobilize the seeds. Evaluation of the radiation dose distribution revealed that the non-immobilized seed movement would change the planned isodose distribution considerably; while by using surgical glue method to immobilize the seeds, the changes were negligible. Prostate brachytherapy seed immobilization is necessary and three alternative mechanisms are promising for addressing this issue. Experiments for exploring the efficacy of the other two proposed methods are ongoing. Devices compatible with the brachytherapy procedure will be designed in future. (orig.)

  4. Human errors and work performance in a nuclear power plant control room: associations with work-related factors and behavioral coping

    Energy Technology Data Exchange (ETDEWEB)

    Kecklund, Lena Jacobsson; Svenson, Ola

    1997-04-01

    The present study investigated the relationships between the operator's appraisal of his own work situation and the quality of his own work performance as well as self-reported errors in a nuclear power plant control room. In all, 98 control room operators from two nuclear power units filled out a questionnaire and several diaries during two operational conditions, annual outage and normal operation. As expected, the operators reported higher work demands in annual outage as compared to normal operation. In response to the increased demands, the operators reported that they used coping strategies such as increased effort, decreased aspiration level for work performance quality and increased use of delegation of tasks to others. This way of coping does not reflect less positive motivation for the work during the outage period. Instead, the operators maintain the same positive motivation for their work, and succeed in being more alert during morning and night shifts. However, the operators feel less satisfied with their work result. The operators also perceive the risk of making minor errors as increasing during outage. The decreased level of satisfaction with work result during outage is a fact despite the lowering of aspiration level for work performance quality during outage. In order to decrease relative frequencies for minor errors, special attention should be given to reduce work demands, such as time pressure and memory demands. In order to decrease misinterpretation errors special attention should be given to organizational factors such as planning and shift turnovers in addition to training. In summary, the outage period seems to be a significantly more vulnerable window in the management of a nuclear power plant than the normal power production state. Thus, an increased focus on the outage period and human factors issues, addressing the synergetic effects or work demands, organizational factors and coping resources is an important area for improvement

  5. Human errors and work performance in a nuclear power plant control room: associations with work-related factors and behavioral coping

    International Nuclear Information System (INIS)

    The present study investigated the relationships between the operator's appraisal of his own work situation and the quality of his own work performance as well as self-reported errors in a nuclear power plant control room. In all, 98 control room operators from two nuclear power units filled out a questionnaire and several diaries during two operational conditions, annual outage and normal operation. As expected, the operators reported higher work demands in annual outage as compared to normal operation. In response to the increased demands, the operators reported that they used coping strategies such as increased effort, decreased aspiration level for work performance quality and increased use of delegation of tasks to others. This way of coping does not reflect less positive motivation for the work during the outage period. Instead, the operators maintain the same positive motivation for their work, and succeed in being more alert during morning and night shifts. However, the operators feel less satisfied with their work result. The operators also perceive the risk of making minor errors as increasing during outage. The decreased level of satisfaction with work result during outage is a fact despite the lowering of aspiration level for work performance quality during outage. In order to decrease relative frequencies for minor errors, special attention should be given to reduce work demands, such as time pressure and memory demands. In order to decrease misinterpretation errors special attention should be given to organizational factors such as planning and shift turnovers in addition to training. In summary, the outage period seems to be a significantly more vulnerable window in the management of a nuclear power plant than the normal power production state. Thus, an increased focus on the outage period and human factors issues, addressing the synergetic effects or work demands, organizational factors and coping resources is an important area for improvement of

  6. Limitation and further development of seismic PSA in the view points of design human error and failure of safety-related logical system

    International Nuclear Information System (INIS)

    This paper deals with the limitation and its further development of Seismic PSA (probabilistic safety assessment) in the view point of human error in structural design and construction process, and also logical failure of safety-related computers, instrumentation systems, logical mechanics such as pilot-operated safety valves under seismic events. Shibata, one of the authors, has been collecting the data on damages of industrial facilities due to past destructive earthquakes since 1964, and he concluded that both logical problems were also significant factors for Seismic PSA as well as the factors which had been discussed such as local seismicity, response fluctuation, and fragility curve. The authors recognized this fact through the cooperative study on Seismic PSA as an activity of the Subcommittee on Seismic Risk Study, to which the authors belong, in the Japan Atomic Energy Research Institute (JAERI). This paper consists of three parts. The first part deals with the summary of the JAERI's work and their issues. The second and third parts deal with human error which will be expected in structural design process and logical failure of logical systems

  7. Iodine-125 interstitial brachytherapy for experimental liver cancer

    Institute of Scientific and Technical Information of China (English)

    ZHOU Fei-guo; YAN Jian-jun; HUANG Liang; LIU Cai-feng; ZHANG Xiang-hua; ZHOU Wei-ping; YAN Yi-qun

    2007-01-01

    Objective:To study the effect of iodine-125 interstitial brachytherapy on liver cancer.Methods:Animal model of human liver cancer was established by injecting SMMC-7721 cells cultivated in vitro subcutaneously into the flank of BALB/c nude mice.Nude mice with tumor of 5 mm in diameter were randomly divided into 2 groups(n=10).One iodine-125 seed of apparent activity 0.8 mCi was implanted into the center of tumor in treatment group,whereas an inactive seed was implanted in control group.The other 20 nude mice with tumor reaching 10 mm in diameter were also treated as above.The size of tumor was determined weekly after implantation,and pathological examination and blood routine were taken on the 28th day.Results:Tumor growth was obviously inhibited in treatment group of tumor of 5 mm in diameter,and there was statistically significant difference in tumor volume between treatment and control groups(P<0.01).Around iodine-125 seed,apparent necrosis of tumor was shown in treatment group,accompanied by karyopyknosis and reduced plasma in residual tumor cells microscopically.Tumor growth was not inhibited in either treatment or control group of tumor of 10 mm in diameter.There was no obvious adverse effect except for decreased white blood cells in treatment groups.Conclusion:There is certain effect of iodine-125 interstitial brachytherapy on liver cancer,which is associated with the size of tumor.

  8. Error analysis in laparoscopic surgery

    Science.gov (United States)

    Gantert, Walter A.; Tendick, Frank; Bhoyrul, Sunil; Tyrrell, Dana; Fujino, Yukio; Rangel, Shawn; Patti, Marco G.; Way, Lawrence W.

    1998-06-01

    Iatrogenic complications in laparoscopic surgery, as in any field, stem from human error. In recent years, cognitive psychologists have developed theories for understanding and analyzing human error, and the application of these principles has decreased error rates in the aviation and nuclear power industries. The purpose of this study was to apply error analysis to laparoscopic surgery and evaluate its potential for preventing complications. Our approach is based on James Reason's framework using a classification of errors according to three performance levels: at the skill- based performance level, slips are caused by attention failures, and lapses result form memory failures. Rule-based mistakes constitute the second level. Knowledge-based mistakes occur at the highest performance level and are caused by shortcomings in conscious processing. These errors committed by the performer 'at the sharp end' occur in typical situations which often times are brought about by already built-in latent system failures. We present a series of case studies in laparoscopic surgery in which errors are classified and the influence of intrinsic failures and extrinsic system flaws are evaluated. Most serious technical errors in lap surgery stem from a rule-based or knowledge- based mistake triggered by cognitive underspecification due to incomplete or illusory visual input information. Error analysis in laparoscopic surgery should be able to improve human performance, and it should detect and help eliminate system flaws. Complication rates in laparoscopic surgery due to technical errors can thus be considerably reduced.

  9. Radiation Exposure Reduction to Brachytherapy Staff By Using Remote Afterloading

    International Nuclear Information System (INIS)

    The radiation exposures to the personnel staff from patients with brachytherapy implants in a brachytherapy service were reviewed. Exposures to the brachytherapy personnel, as determined by Thermoluminescence Dosimeter (TLD) monitors, indicates a four-fold reduction in exposures after the implantation of the use of remote afterloading devices. Quarterly TLD monitor data for seven quarters prior to the use of remote afterloading devices demonstrate an average projected annual dose equivalent to the brachytherapy staff of 2543 Μ Sv. After the implantation of the remote afterloading devices, the quarterly TLD monitor data indicate an average dose equivalent per person of 153 Μ Sv. This is 76% reduction in exposure to brachytherapy personnel with the use of these devices

  10. Gold marker displacement due to needle insertion during HDR-brachytherapy for treatment of prostate cancer: A prospective cone beam computed tomography and kilovoltage on-board imaging (kV-OBI) study

    International Nuclear Information System (INIS)

    To evaluate gold marker displacement due to needle insertion during HDR-brachytherapy for therapy of prostate cancer. 18 patients entered into this prospective evaluation. Three gold markers were implanted into the prostate during the first HDR-brachytherapy procedure after the irradiation was administered. Three days after marker implantation all patients had a CT-scan for planning purpose of the percutaneous irradiation. Marker localization was defined on the digitally-reconstructed-radiographs (DRR) for daily (VMAT technique) or weekly (IMRT) set-up error correction. Percutaneous therapy started one week after first HDR-brachytherapy. After the second HDR-brachytherapy, two weeks after first HDR-brachtherapy, a cone-beam CT-scan was done to evaluate marker displacement due to needle insertion. In case of marker displacement, the actual positions of the gold markers were adjusted on the DRR. The value of the gold marker displacement due to the second HDR-brachytherapy was analyzed in all patients and for each gold marker by comparison of the marker positions in the prostate after soft tissue registration of the prostate of the CT-scans prior the first and second HDR-brachytherapy. The maximum deviation was 5 mm, 7 mm and 12 mm for the anterior-posterior, lateral and superior-inferior direction. At least one marker in each patient showed a significant displacement and therefore new marker positions were adjusted on the DRRs for the ongoing percutaneous therapy. Needle insertion in the prostate due to HDR-brachytherapy can lead to gold marker displacements. Therefore, it is necessary to verify the actual position of markers after the second HDR-brachytherapy. In case of significant deviations, a new DRR with the adjusted marker positions should be generated for precise positioning during the ongoing percutaneous irradiation

  11. Penile brachytherapy: Results for 49 patients

    International Nuclear Information System (INIS)

    Purpose: To report results for 49 men with squamous cell carcinoma (SCC) of the penis treated with primary penile interstitial brachytherapy at one of two institutions: the Ottawa Regional Cancer Center, Ottawa, and the Princess Margaret Hospital, Toronto, Ontario, Canada. Methods and Materials: From September 1989 to September 2003, 49 men (mean age, 58 years; range, 22-93 years) had brachytherapy for penile SCC. Fifty-one percent of tumors were T1, 33% T2, and 8% T3; 4% were in situ and 4% Tx. Grade was well differentiated in 31%, moderate in 45%, and poor in 2%; grade was unspecified for 20%. One tumor was verrucous. All tumors in Toronto had pulsed dose rate (PDR) brachytherapy (n = 23), whereas those in Ottawa had either Iridium wire (n 22) or seeds (n = 4). Four patients had a single plane implant with a plastic tube technique, and all others had a volume implant with predrilled acrylic templates and two or three parallel planes of needles (median, six needles). Mean needle spacing was 13.5 mm (range, 10-18 mm), mean dose rate was 65 cGy/h (range, 33-160 cGy/h), and mean duration was 98.8 h (range, 36-188 h). Dose rates for PDR brachytherapy were 50-61.2 cGy/h, with no correction in total dose, which was 60 Gy in all cases. Results: Median follow-up was 33.4 months (range, 4-140 months). At 5 years, actuarial overall survival was 78.3% and cause-specific survival 90.0%. Four men died of penile cancer, and 6 died of other causes with no evidence of recurrence. The cumulative incidence rate for never having experienced any type of failure at 5 years was 64.4% and for local failure was 85.3%. All 5 patients with local failure were successfully salvaged by surgery; 2 other men required penectomy for necrosis. The soft tissue necrosis rate was 16% and the urethral stenosis rate 12%. Of 8 men with regional failure, 5 were salvaged by lymph node dissection with or without external radiation. All 4 men with distant failure died of disease. Of 49 men, 42 had an intact

  12. Review of clinical brachytherapy uncertainties: Analysis guidelines of GEC-ESTRO and the AAPM

    International Nuclear Information System (INIS)

    Background and purpose: A substantial reduction of uncertainties in clinical brachytherapy should result in improved outcome in terms of increased local control and reduced side effects. Types of uncertainties have to be identified, grouped, and quantified. Methods: A detailed literature review was performed to identify uncertainty components and their relative importance to the combined overall uncertainty. Results: Very few components (e.g., source strength and afterloader timer) are independent of clinical disease site and location of administered dose. While the influence of medium on dose calculation can be substantial for low energy sources or non-deeply seated implants, the influence of medium is of minor importance for high-energy sources in the pelvic region. The level of uncertainties due to target, organ, applicator, and/or source movement in relation to the geometry assumed for treatment planning is highly dependent on fractionation and the level of image guided adaptive treatment. Most studies to date report the results in a manner that allows no direct reproduction and further comparison with other studies. Often, no distinction is made between variations, uncertainties, and errors or mistakes. The literature review facilitated the drafting of recommendations for uniform uncertainty reporting in clinical BT, which are also provided. The recommended comprehensive uncertainty investigations are key to obtain a general impression of uncertainties, and may help to identify elements of the brachytherapy treatment process that need improvement in terms of diminishing their dosimetric uncertainties. It is recommended to present data on the analyzed parameters (distance shifts, volume changes, source or applicator position, etc.), and also their influence on absorbed dose for clinically-relevant dose parameters (e.g., target parameters such as D90 or OAR doses). Publications on brachytherapy should include a statement of total dose uncertainty for the entire

  13. Erectile function after permanent prostate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To determine the incidence of potency preservation after permanent prostate brachytherapy using a validated patient-administered questionnaire and to evaluate the effect of multiple clinical and treatment parameters on penile erectile function. Methods and Materials: Four hundred twenty-five patients underwent permanent prostate brachytherapy from April 1995 to October 1999. Two hundred nine patients who were potent before brachytherapy and who at the time of the survey were not receiving hormonal therapy were mailed the specific erectile questions of the International Index of Erectile Function (IIEF) questionnaire with a self-addressed stamped envelope. The questionnaire consisted of 5 questions, with a maximal score of 25. Of the 209 patients, 181 (87%) completed and returned the questionnaire. The mean and median follow-up was 40.4±14.9 and 40.6 months, respectively (range 19-75). Preimplant erectile function was assigned using a three-tiered scoring system (2 = erections always or nearly always sufficient for vaginal penetration; 1 = erections sufficient for vaginal penetration but considered suboptimal; 0 = the inability to obtain erections and/or erections inadequate for vaginal penetration). Postimplant potency was defined as an IIEF score ≥11. The clinical parameters evaluated for erectile function included patient age, preimplant potency, clinical T-stage, pretreatment prostate-specific antigen level, Gleason score, elapsed time after implantation, hypertension, diabetes mellitus, and tobacco consumption. Treatment parameters included radiation dose to the prostate gland, use of hormonal manipulation, use of supplemental external beam radiotherapy (EBRT), choice of isotope, prostate volume, and planning volume. The efficacy of sildenafil citrate in brachytherapy-induced erectile dysfunction (ED) was also evaluated. Results: Pretreatment erectile function scores of 2 and 1 were assigned to 125 and 56 patients, respectively. With a 6-year follow

  14. Building a World-Class Safety Culture: The National Ignition Facility and the Control of Human and Organizational Error

    International Nuclear Information System (INIS)

    Accidents in complex systems send us signals. They may be harbingers of a catastrophe. Some even argue that a ''normal'' consequence of operations in a complex organization may not only be the goods it produces, but also accidents and--inevitably--catastrophes. We would like to tell you the story of a large, complex organization, whose history questions the argument ''that accidents just happen.'' Starting from a less than enviable safety record, the National Ignition Facility (NIF) has accumulated over 2.5 million safe hours. The story of NIF is still unfolding. The facility is still being constructed and commissioned. But the steps NIF has taken in achieving its safety record provide a principled blueprint that may be of value to others. Describing that principled blueprint is the purpose of this paper. The first part of this paper is a case study of NIF and its effort to achieve a world-class safety record. This case study will include a description of (1) NIF's complex systems, (2) NIF's early safety history, (3) factors that may have initiated its safety culture change, and (4) the evolution of its safety blueprint. In the last part of the paper, we will compare NIF's safety culture to what safety industry experts, psychologists, and sociologists say about how to shape a culture and control organizational error

  15. Building a World-Class Safety Culture: The National Ignition Facility and the Control of Human and Organizational Error

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, C T; Stalnaker, G

    2002-12-06

    Accidents in complex systems send us signals. They may be harbingers of a catastrophe. Some even argue that a ''normal'' consequence of operations in a complex organization may not only be the goods it produces, but also accidents and--inevitably--catastrophes. We would like to tell you the story of a large, complex organization, whose history questions the argument ''that accidents just happen.'' Starting from a less than enviable safety record, the National Ignition Facility (NIF) has accumulated over 2.5 million safe hours. The story of NIF is still unfolding. The facility is still being constructed and commissioned. But the steps NIF has taken in achieving its safety record provide a principled blueprint that may be of value to others. Describing that principled blueprint is the purpose of this paper. The first part of this paper is a case study of NIF and its effort to achieve a world-class safety record. This case study will include a description of (1) NIF's complex systems, (2) NIF's early safety history, (3) factors that may have initiated its safety culture change, and (4) the evolution of its safety blueprint. In the last part of the paper, we will compare NIF's safety culture to what safety industry experts, psychologists, and sociologists say about how to shape a culture and control organizational error.

  16. Quality control of the breast cancer treatments on Hdr brachytherapy with TLD-100

    International Nuclear Information System (INIS)

    An anthropomorphic Phantom, a female trunk, was built with a natural bone structure and experimental material coated, glycerin and water-based material called JJT to build soft tissue equivalent to the muscle of human tissue, and a polymer (styrofoam) to build the lung as critical organ to simulate the treatment of breast cancer, with high dose rate brachytherapy (Hdr) and sources of Ir-192. The treatments were planned and calculated for the critical organ: Lung, and injury of 2 cm in diameter in breast with Micro Selectron Hdr system and the software Plato Brachytherapy V 14.1 of the Nucletron (Netherlands) which uses the standard protocol of radiotherapy for brachytherapy treatments. The dose experimentally measured with dosimeters TLD-100 LiF: Mg; Ti, which were previously calibrated, were placed in the same positions and bodies mentioned above, with less than 5% uncertainty. The reading dosimeters was carried out in a Harshaw TLD 4500. The results obtained for calculated treatments, using the standard simulator, and the experimental with TLD-100, show a high concordance, as they are on average a ± 1.1% making process becomes in a quality control of this type of treatments. (Author)

  17. Quality control of the breast cancer treatments on Hdr brachytherapy with TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Torres H, F. [Universidad de Cordoba, Materials and Applied Physics Group, 230002 Monteria, Cordoba (Colombia); De la Espriella V, N. [Universidad de Cordoba, Grupo Avanzado de Materiales y Sistemas Complejos, 230002 Monteria, Cordoba (Colombia); Sanchez C, A., E-mail: franciscotorreshoyos@yahoo.com [Universidad de Cordoba, Departamento de Enfermeria, 230002 Monteria, Cordoba (Colombia)

    2014-07-01

    An anthropomorphic Phantom, a female trunk, was built with a natural bone structure and experimental material coated, glycerin and water-based material called JJT to build soft tissue equivalent to the muscle of human tissue, and a polymer (styrofoam) to build the lung as critical organ to simulate the treatment of breast cancer, with high dose rate brachytherapy (Hdr) and sources of Ir-192. The treatments were planned and calculated for the critical organ: Lung, and injury of 2 cm in diameter in breast with Micro Selectron Hdr system and the software Plato Brachytherapy V 14.1 of the Nucletron (Netherlands) which uses the standard protocol of radiotherapy for brachytherapy treatments. The dose experimentally measured with dosimeters TLD-100 LiF: Mg; Ti, which were previously calibrated, were placed in the same positions and bodies mentioned above, with less than 5% uncertainty. The reading dosimeters was carried out in a Harshaw TLD 4500. The results obtained for calculated treatments, using the standard simulator, and the experimental with TLD-100, show a high concordance, as they are on average a ± 1.1% making process becomes in a quality control of this type of treatments. (Author)

  18. New brachytherapy standards paradigm shift

    International Nuclear Information System (INIS)

    Full text: The absorbed dose rate to water at short distances (1 cm typically) in water, is the quantity of interest for dosimetry in radiotherapy treatments. Moreover, the dose imparted to cancer patients must be known within a narrow band of uncertainty to avoid either damage to the healthy tissue resulting from exceeding international accepted tolerance levels or lack of tumor control due to a low dose delivered to the target volume. The goal for the uncertainty of the dose delivered to the target volume would be around 5% (at the level of one standard deviation), to assure the effectiveness of the radiotherapy treatment. This also takes into account the uncertainties in dose calculation algorithms. In current brachytherapy (BT) treatments, the procedures to determine the absorbed dose imparted to the patient are not based on absorbed dose standards, but are based on measurements traceable to air kerma standards. In fact, the recommended quantity for the calibration of BT gamma ray sources is the reference air kerma rate, KR, defined as the kerma rate to air, in air, at the reference distance of 1 m from the radioactive source, corrected for air attenuation and scattering. The absorbed dose around a BT source is currently calculated by applying the formalism of the international AAPM Task Group 43 protocol and its update. This protocol is based on the air kerma strength, SK, a quantity that is numerically equivalent to KR, at a distance of 1 m from the source. The dose rate constant Λ converts the air-kerma strength SK to the absorbed dose rate to water, D.(r0,θ0), in water at the reference position: D.(r0,θ0) = SK·A (1). Recently, a lower limit of 2,50 % was obtained for the estimated overall uncertainty (at the level of one standard deviation) on measurements of D.(r0,θ0) due to a HDR 192I BT source based on equation (1). However, in most cases the determination of 5K is typically affected by an uncertainty within 0,8 % (at the level of one standard

  19. A fully actuated robotic assistant for MRI-guided prostate biopsy and brachytherapy

    Science.gov (United States)

    Li, Gang; Su, Hao; Shang, Weijian; Tokuda, Junichi; Hata, Nobuhiko; Tempany, Clare M.; Fischer, Gregory S.

    2013-03-01

    Intra-operative medical imaging enables incorporation of human experience and intelligence in a controlled, closed-loop fashion. Magnetic resonance imaging (MRI) is an ideal modality for surgical guidance of diagnostic and therapeutic procedures, with its ability to perform high resolution, real-time, high soft tissue contrast imaging without ionizing radiation. However, for most current image-guided approaches only static pre-operative images are accessible for guidance, which are unable to provide updated information during a surgical procedure. The high magnetic field, electrical interference, and limited access of closed-bore MRI render great challenges to developing robotic systems that can perform inside a diagnostic high-field MRI while obtaining interactively updated MR images. To overcome these limitations, we are developing a piezoelectrically actuated robotic assistant for actuated percutaneous prostate interventions under real-time MRI guidance. Utilizing a modular design, the system enables coherent and straight forward workflow for various percutaneous interventions, including prostate biopsy sampling and brachytherapy seed placement, using various needle driver configurations. The unified workflow compromises: 1) system hardware and software initialization, 2) fiducial frame registration, 3) target selection and motion planning, 4) moving to the target and performing the intervention (e.g. taking a biopsy sample) under live imaging, and 5) visualization and verification. Phantom experiments of prostate biopsy and brachytherapy were executed under MRI-guidance to evaluate the feasibility of the workflow. The robot successfully performed fully actuated biopsy sampling and delivery of simulated brachytherapy seeds under live MR imaging, as well as precise delivery of a prostate brachytherapy seed distribution with an RMS accuracy of 0.98mm.

  20. Ocular brachytherapy dosimetry for 103Pd and 125I in the presence of gold nanoparticles: a Monte Carlo study.

    Science.gov (United States)

    Asadi, Somayeh; Vaez-Zadeh, Mehdi; Vahidian, Mohammad; Marghchouei, Mahdieh; Masoudi, S Farhad

    2016-01-01

    The aim of the present Monte Carlo study is to evaluate the variation of energy deposition in healthy tissues in the human eye which is irradiated by brachytherapy sources in comparison with the resultant dose increase in the gold nanoparticle (GNP)-loaded choroidal melanoma. The effects of these nanoparticles on normal tissues are compared between 103Pd and 125I as two ophthalmic brachytherapy sources. Dose distribution in the tumor and healthy tissues has been taken into account for both brachytherapy sources. Also, in certain points of the eye, the ratio of the absorbed dose by the normal tissue in the presence of GNPs to the absorbed dose by the same point in the absence of GNPs has been calculated. In addition, differences of the absorbed dose in the tumor observed in the comparison of simple water phantom and actual simulated human eye in presence of GNPs are also a matter of interest that have been considered in the present work. The difference between the eye globe and the water phantom is more obvious for 125I than that of the 103Pd when the ophthalmic dosimetry is done in the presence of GNPs. Whenever these nanoparticles are utilized in enhancing the absorbed dose by the tumor, the use of 125I brachytherapy source will greatly amplify the amount of dose enhancement factor (DEF) in the tumor site without inflicting much dam-age to healthy organs, when compared to the 103Pd source. For instance, in the concentration of 30 mg GNPs, the difference amongst the calculated DEF for 125I between these phantoms is 5.3%, while it is 2.45% for 103Pd. Furthermore, in Monte Carlo studies of eye brachytherapy, more precise definition of the eye phantom instead of a water phantom will become increasingly important when we use 125I as opposed to 103Pd. PMID:27167265

  1. A system to use electromagnetic tracking for the quality assurance of brachytherapy catheter digitization

    International Nuclear Information System (INIS)

    Purpose: To investigate the use of a system using electromagnetic tracking (EMT), post-processing and an error-detection algorithm for detecting errors and resolving uncertainties in high-dose-rate brachytherapy catheter digitization for treatment planning. Methods: EMT was used to localize 15 catheters inserted into a phantom using a stepwise acquisition technique. Five distinct acquisition experiments were performed. Noise associated with the acquisition was calculated. The dwell location configuration was extracted from the EMT data. A CT scan of the phantom was performed, and five distinct catheter digitization sessions were performed. No a priori registration of the CT scan coordinate system with the EMT coordinate system was performed. CT-based digitization was automatically extracted from the brachytherapy plan DICOM files (CT), and rigid registration was performed between EMT and CT dwell positions. EMT registration error was characterized in terms of the mean and maximum distance between corresponding EMT and CT dwell positions per catheter. An algorithm for error detection and identification was presented. Three types of errors were systematically simulated: swap of two catheter numbers, partial swap of catheter number identification for parts of the catheters (mix), and catheter-tip shift. Error-detection sensitivity (number of simulated scenarios correctly identified as containing an error/number of simulated scenarios containing an error) and specificity (number of scenarios correctly identified as not containing errors/number of correct scenarios) were calculated. Catheter identification sensitivity (number of catheters correctly identified as erroneous across all scenarios/number of erroneous catheters across all scenarios) and specificity (number of catheters correctly identified as correct across all scenarios/number of correct catheters across all scenarios) were calculated. The mean detected and identified shift was calculated. Results: The

  2. A system to use electromagnetic tracking for the quality assurance of brachytherapy catheter digitization

    Energy Technology Data Exchange (ETDEWEB)

    Damato, Antonio L., E-mail: adamato@lroc.harvard.edu; Viswanathan, Akila N.; Don, Sarah M.; Hansen, Jorgen L.; Cormack, Robert A. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States)

    2014-10-15

    Purpose: To investigate the use of a system using electromagnetic tracking (EMT), post-processing and an error-detection algorithm for detecting errors and resolving uncertainties in high-dose-rate brachytherapy catheter digitization for treatment planning. Methods: EMT was used to localize 15 catheters inserted into a phantom using a stepwise acquisition technique. Five distinct acquisition experiments were performed. Noise associated with the acquisition was calculated. The dwell location configuration was extracted from the EMT data. A CT scan of the phantom was performed, and five distinct catheter digitization sessions were performed. No a priori registration of the CT scan coordinate system with the EMT coordinate system was performed. CT-based digitization was automatically extracted from the brachytherapy plan DICOM files (CT), and rigid registration was performed between EMT and CT dwell positions. EMT registration error was characterized in terms of the mean and maximum distance between corresponding EMT and CT dwell positions per catheter. An algorithm for error detection and identification was presented. Three types of errors were systematically simulated: swap of two catheter numbers, partial swap of catheter number identification for parts of the catheters (mix), and catheter-tip shift. Error-detection sensitivity (number of simulated scenarios correctly identified as containing an error/number of simulated scenarios containing an error) and specificity (number of scenarios correctly identified as not containing errors/number of correct scenarios) were calculated. Catheter identification sensitivity (number of catheters correctly identified as erroneous across all scenarios/number of erroneous catheters across all scenarios) and specificity (number of catheters correctly identified as correct across all scenarios/number of correct catheters across all scenarios) were calculated. The mean detected and identified shift was calculated. Results: The

  3. Robot-assisted 3D-TRUS guided prostate brachytherapy: System integration and validation

    International Nuclear Information System (INIS)

    Current transperineal prostate brachytherapy uses transrectal ultrasound (TRUS) guidance and a template at a fixed position to guide needles along parallel trajectories. However, pubic arch interference (PAI) with the implant path obstructs part of the prostate from being targeted by the brachytherapy needles along parallel trajectories. To solve the PAI problem, some investigators have explored other insertion trajectories than parallel, i.e., oblique. However, parallel trajectory constraints in current brachytherapy procedure do not allow oblique insertion. In this paper, we describe a robot-assisted, three-dimensional (3D) TRUS guided approach to solve this problem. Our prototype consists of a commercial robot, and a 3D TRUS imaging system including an ultrasound machine, image acquisition apparatus and 3D TRUS image reconstruction, and display software. In our approach, we use the robot as a movable needle guide, i.e., the robot positions the needle before insertion, but the physician inserts the needle into the patient's prostate. In a later phase of our work, we will include robot insertion. By unifying the robot, ultrasound transducer, and the 3D TRUS image coordinate systems, the position of the template hole can be accurately related to 3D TRUS image coordinate system, allowing accurate and consistent insertion of the needle via the template hole into the targeted position in the prostate. The unification of the various coordinate systems includes two steps, i.e., 3D image calibration and robot calibration. Our testing of the system showed that the needle placement accuracy of the robot system at the 'patient's' skin position was 0.15 mm±0.06 mm, and the mean needle angulation error was 0.07 deg. . The fiducial localization error (FLE) in localizing the intersections of the nylon strings for image calibration was 0.13 mm, and the FLE in localizing the divots for robot calibration was 0.37 mm. The fiducial registration error for image calibration was 0

  4. Errors in Neonatology

    Directory of Open Access Journals (Sweden)

    Antonio Boldrini

    2013-06-01

    Full Text Available Introduction: Danger and errors are inherent in human activities. In medical practice errors can lean to adverse events for patients. Mass media echo the whole scenario. Methods: We reviewed recent published papers in PubMed database to focus on the evidence and management of errors in medical practice in general and in Neonatology in particular. We compared the results of the literature with our specific experience in Nina Simulation Centre (Pisa, Italy. Results: In Neonatology the main error domains are: medication and total parenteral nutrition, resuscitation and respiratory care, invasive procedures, nosocomial infections, patient identification, diagnostics. Risk factors include patients’ size, prematurity, vulnerability and underlying disease conditions but also multidisciplinary teams, working conditions providing fatigue, a large variety of treatment and investigative modalities needed. Discussion and Conclusions: In our opinion, it is hardly possible to change the human beings but it is likely possible to change the conditions under they work. Voluntary errors report systems can help in preventing adverse events. Education and re-training by means of simulation can be an effective strategy too. In Pisa (Italy Nina (ceNtro di FormazIone e SimulazioNe NeonAtale is a simulation center that offers the possibility of a continuous retraining for technical and non-technical skills to optimize neonatological care strategies. Furthermore, we have been working on a novel skill trainer for mechanical ventilation (MEchatronic REspiratory System SImulator for Neonatal Applications, MERESSINA. Finally, in our opinion national health policy indirectly influences risk for errors. Proceedings of the 9th International Workshop on Neonatology · Cagliari (Italy · October 23rd-26th, 2013 · Learned lessons, changing practice and cutting-edge research

  5. Error monitoring in musicians

    Directory of Open Access Journals (Sweden)

    Clemens Maidhof

    2013-07-01

    Full Text Available To err is human, and hence even professional musicians make errors occasionally during their performances. This paper summarizes recent work investigating error monitoring in musicians, i.e. the processes and their neural correlates associated with the monitoring of ongoing actions and the detection of deviations from intended sounds. EEG Studies reported an early component of the event-related potential (ERP occurring before the onsets of pitch errors. This component, which can be altered in musicians with focal dystonia, likely reflects processes of error detection and/or error compensation, i.e. attempts to cancel the undesired sensory consequence (a wrong tone a musician is about to perceive. Thus, auditory feedback seems not to be a prerequisite for error detection, consistent with previous behavioral results. In contrast, when auditory feedback is externally manipulated and thus unexpected, motor performance can be severely distorted, although not all feedback alterations result in performance impairments. Recent studies investigating the neural correlates of feedback processing showed that unexpected feedback elicits an ERP component after note onsets, which shows larger amplitudes during music performance than during mere perception of the same musical sequences. Hence, these results stress the role of motor actions for the processing of auditory information. Furthermore, recent methodological advances like the combination of 3D motion capture techniques with EEG will be discussed. Such combinations of different measures can potentially help to disentangle the roles of different feedback types such as proprioceptive and auditory feedback, and in general to derive at a better understanding of the complex interactions between the motor and auditory domain during error monitoring. Finally, outstanding questions and future directions in this context will be discussed.

  6. Caudal epidural anesthesia during intracavitary brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    It has been suggested that pain control during intracavitary brachytherapy for cervical cancer is insufficient in most hospitals in Japan. Our hospital began using caudal epidural anesthesia during high-dose-rate (HDR) intracavitary brachytherapy in 2011. The purpose of the present study was to retrospectively investigate the effects of caudal epidural anesthesia during HDR intracavitary brachytherapy for cervical cancer patients. Caudal epidural anesthesia for 34 cervical cancer patients was performed during HDR intracavitary brachytherapy between October 2011 and August 2013. We used the patients' self-reported Numeric Rating Scale (NRS) score at the first session of HDR intracavitary brachytherapy as a subjective evaluation of pain. We compared NRS scores of the patients with anesthesia with those of 30 patients who underwent HDR intracavitary brachytherapy without sacral epidural anesthesia at our hospital between May 2010 and August 2011. Caudal epidural anesthesia succeeded in 33 patients (97%), and the NRS score was recorded in 30 patients. The mean NRS score of the anesthesia group was 5.17 ± 2.97, significantly lower than that of the control group's 6.80 ± 2.59 (P = 0.035). The caudal epidural block resulted in no side-effects. Caudal epidural anesthesia is an effective and safe anesthesia option during HDR intracavitary brachytherapy for cervical cancer. (author)

  7. Radiation Protection in Brachytherapy in the Next Decade

    International Nuclear Information System (INIS)

    Brachytherapy procedures are increasing in number, and account for an important share of radiation exposure in medicine at a time when there is a dramatic rise in cancer across the developing world. Important areas in relation to radiation safety in brachytherapy include that all efforts be made to ensure that protection in the treatment is optimized and all measures are taken to prevent accidental exposures from occurring. Historical and ongoing accidents that have resulted in patient and public doses or inappropriate medical outcomes represent opportunities for continuous improvement in radiation protection. Additionally, staff in brachytherapy treatment facilities may receive high radiation doses if radiological protection tools are not used properly. Brachytherapy uniquely presents the possibility for doses that require active management. In modern brachytherapy centres, radiation doses are incurred by staff (e.g. loading of seeds, plaques, caesium implants, associated fluoroscopy). There is also a large variation in the practice of brachytherapy on a global scale and several facilities still practise older techniques with significantly higher staff dose potential. In addition, technological developments and newer techniques present new radiation protection concerns and an increasing blurring of historical responsibilities that need to be addressed with specific recommendations for the practising medical community. Along with an increase in equipment and to safeguard resources, additional qualified and trained brachytherapy staff are required worldwide. (author)

  8. The dosimetry of brachytherapy-induced erectile dysfunction

    International Nuclear Information System (INIS)

    There is emerging evidence that brachytherapy-induced erectile dysfunction (ED) is technique-related and may be minimized by careful attention to source placement. Herein, we review the relationship between radiation doses to the prostate gland/surrounding structures and the development of brachytherapy-induced ED. The permanent prostate brachytherapy literature was reviewed using MEDLINE searches to ensure completeness. Although the site-specific structure associated with brachytherapy-induced ED remains unknown, there is an increasing body of data implicating the proximal penis. With day 0 CT-based dosimetry, the dose to 50% (D50) and 25% (D25) of the bulb of the penis should be maintained below 40% and 60% mPD, respectively, while the crura D50 should be maintained below 28% mPD to maximize post-brachytherapy potency. To date, there is no data to suggest that either radiation doses to the neurovascular bundles or choice of isotope is associated with brachytherapy-induced ED, while conflicting data has been reported regarding radiation dose to the prostate and the use of supplemental external beam radiation therapy. Although the etiology of brachytherapy-induced ED is likely multifactorial, the available data supports the proximal penis as an important site-specific structure. Refinements in implant technique, including preplanning and intraoperative seed placement, will result in lower radiation doses to the proximal penis with potential improvement in potency preservation

  9. Multihelix rotating shield brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    Purpose: To present a novel brachytherapy technique, called multihelix rotating shield brachytherapy (H-RSBT), for the precise angular and linear positioning of a partial shield in a curved applicator. H-RSBT mechanically enables the dose delivery using only linear translational motion of the radiation source/shield combination. The previously proposed approach of serial rotating shield brachytherapy (S-RSBT), in which the partial shield is rotated to several angular positions at each source dwell position [W. Yang et al., “Rotating-shield brachytherapy for cervical cancer,” Phys. Med. Biol. 58, 3931–3941 (2013)], is mechanically challenging to implement in a curved applicator, and H-RSBT is proposed as a feasible solution. Methods: A Henschke-type applicator, designed for an electronic brachytherapy source (Xoft Axxent™) and a 0.5 mm thick tungsten partial shield with 180° or 45° azimuthal emission angles and 116° asymmetric zenith angle, is proposed. The interior wall of the applicator contains six evenly spaced helical keyways that rigidly define the emission direction of the partial radiation shield as a function of depth in the applicator. The shield contains three uniformly distributed protruding keys on its exterior wall and is attached to the source such that it rotates freely, thus longitudinal translational motion of the source is transferred to rotational motion of the shield. S-RSBT and H-RSBT treatment plans with 180° and 45° azimuthal emission angles were generated for five cervical cancer patients with a diverse range of high-risk target volume (HR-CTV) shapes and applicator positions. For each patient, the total number of emission angles was held nearly constant for S-RSBT and H-RSBT by using dwell positions separated by 5 and 1.7 mm, respectively, and emission directions separated by 22.5° and 60°, respectively. Treatment delivery time and tumor coverage (D90 of HR-CTV) were the two metrics used as the basis for evaluation and

  10. Multihelix rotating shield brachytherapy for cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dadkhah, Hossein [Department of Biomedical Engineering, University of Iowa, 1402 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242 (United States); Kim, Yusung; Flynn, Ryan T., E-mail: ryan-flynn@uiowa.edu [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Wu, Xiaodong [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 and Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242 (United States)

    2015-11-15

    Purpose: To present a novel brachytherapy technique, called multihelix rotating shield brachytherapy (H-RSBT), for the precise angular and linear positioning of a partial shield in a curved applicator. H-RSBT mechanically enables the dose delivery using only linear translational motion of the radiation source/shield combination. The previously proposed approach of serial rotating shield brachytherapy (S-RSBT), in which the partial shield is rotated to several angular positions at each source dwell position [W. Yang et al., “Rotating-shield brachytherapy for cervical cancer,” Phys. Med. Biol. 58, 3931–3941 (2013)], is mechanically challenging to implement in a curved applicator, and H-RSBT is proposed as a feasible solution. Methods: A Henschke-type applicator, designed for an electronic brachytherapy source (Xoft Axxent™) and a 0.5 mm thick tungsten partial shield with 180° or 45° azimuthal emission angles and 116° asymmetric zenith angle, is proposed. The interior wall of the applicator contains six evenly spaced helical keyways that rigidly define the emission direction of the partial radiation shield as a function of depth in the applicator. The shield contains three uniformly distributed protruding keys on its exterior wall and is attached to the source such that it rotates freely, thus longitudinal translational motion of the source is transferred to rotational motion of the shield. S-RSBT and H-RSBT treatment plans with 180° and 45° azimuthal emission angles were generated for five cervical cancer patients with a diverse range of high-risk target volume (HR-CTV) shapes and applicator positions. For each patient, the total number of emission angles was held nearly constant for S-RSBT and H-RSBT by using dwell positions separated by 5 and 1.7 mm, respectively, and emission directions separated by 22.5° and 60°, respectively. Treatment delivery time and tumor coverage (D{sub 90} of HR-CTV) were the two metrics used as the basis for evaluation and

  11. Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Guide to data processing and revision: Part 2, Human error probability data entry and revision procedures

    International Nuclear Information System (INIS)

    The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) is an automated data base management system for processing and storing human error probability (HEP) and hardware component failure data (HCFD). The NUCLARR system software resides on an IBM (or compatible) personal micro-computer. Users can perform data base searches to furnish HEP estimates and HCFD rates. In this manner, the NUCLARR system can be used to support a variety of risk assessment activities. This volume, Volume 3 of a 5-volume series, presents the procedures used to process HEP and HCFD for entry in NUCLARR and describes how to modify the existing NUCLARR taxonomy in order to add either equipment types or action verbs. Volume 3 also specifies the various roles of the administrative staff on assignment to the NUCLARR Clearinghouse who are tasked with maintaining the data base, dealing with user requests, and processing NUCLARR data. 5 refs., 34 figs., 3 tabs

  12. Too generous to a fault? Is reliable earthquake safety a lost art? Errors in expected human losses due to incorrect seismic hazard estimates

    Science.gov (United States)

    Bela, James

    2014-11-01

    "One is well advised, when traveling to a new territory, to take a good map and then to check the map with the actual territory during the journey." In just such a reality check, Global Seismic Hazard Assessment Program (GSHAP) maps (prepared using PSHA) portrayed a "low seismic hazard," which was then also assumed to be the "risk to which the populations were exposed." But time-after-time-after-time the actual earthquakes that occurred were not only "surprises" (many times larger than those implied on the maps), but they were often near the maximum potential size (Maximum Credible Earthquake or MCE) that geologically could occur. Given these "errors in expected human losses due to incorrect seismic hazard estimates" revealed globally in these past performances of the GSHAP maps (> 700,000 deaths 2001-2011), we need to ask not only: "Is reliable earthquake safety a lost art?" but also: "Who and what were the `Raiders of the Lost Art?' "

  13. Iridium-192 sources production for brachytherapy use

    International Nuclear Information System (INIS)

    The incidence of cancer increases every year in Brazil and turns out to be one of the most important causes of mortality. Some of the patients are treated with brachytherapy, a form of lesion treatment which is based on the insertion of sources into tumors, in this particular case, activated iridium wires. During this process, the ionizing radiation efficiently destroys the malignant cells. These iridium wires have a nucleus made out of an iridium-platinum alloy 20-30/70-80 of 0,1 mm in diameter either coated by platinum or encased in a platinum tube. The technique consists in irradiating the wire in the reactor neutron flux in order to produce iridium-192. The linear activity goes from 1 mCi/cm to 4 mCi/cm and the basic characteristic, which is required, is the homogeneity of the activation along the wire. It should not present a dispersion exceeding 5% on a wire measuring 50 cm in length, 0.5 mm or 0.3 mm in diameter. Several experiments were carried out in order to define the activation parameters. Wires from different origins were analyzed. It was concluded that United States of America and France wires were found to be perfectly adequate for brachytherapy purposes and have therefore been sent to specialized hospitals and successfully applied to cancer patients. Considering that the major purpose of this work is to make this product more accessible in Brazil, at a cost reflecting the Brazilian reality, the IPEN is promoting the preparation of iridium-192 sources to be used in brachytherapy, on a national level. (author)

  14. Perioperative interstitial brachytherapy for recurrent keloid scars

    International Nuclear Information System (INIS)

    Purpose: Evaluation of the results of perioperative interstitial brachytherapy with low dose-rate (L.D.R.) Ir-192 in the treatment of keloid scars. Patients and methods: We performed a retrospective analysis of 73 histologically confirmed keloids (from 58 patients) resistant to medico surgical treated by surgical excision plus early perioperative brachytherapy. All lesions were initially symptomatic. Local control was evaluated by clinical evaluation. Functional and cosmetic results were assessed in terms of patient responses to a self-administered questionnaire. Results: Median age was 28 years (range 13-71 years). Scars were located as follows: 37% on the face, 32% on the trunk or abdomen, 16% on the neck, and 15% on the arms or legs. The mean delay before loading was four hours (range, 1-6 h). The median dose was 20 Gy (range, 15-40 Gy). Sixty-four scars (from 53 patients) were evaluated. Local control was 86% (follow-up, 44.5 months; range, 14-150 months). All relapses occurred early within 2 years posttreatment. At 20 months, survival without recurrence was significantly lower when treated lengths were more than 6 cm long. The rate was 100% for treated scars below 4.5 cm in length, 95% (95% CI: 55-96) for those 4.5-6 cm long, and 75% (95% CI: 56-88) beyond 6 cm (p = 0.038). Of the 35 scars (28 patients) whose results were reassessed, six remained symptomatic and the esthetic results were considered to be good in 51% (18/35) and average in 37% (13/35) (median follow-up, 70 months; range, 16-181 months). Conclusion: Early perioperative L.D.R. brachytherapy delivering 20 Gy at 5 mm reduced the rate of recurrent keloids resistant to other treatments and gave good functional results. (authors)

  15. Comprehensive Error Rate Testing (CERT)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Centers for Medicare and Medicaid Services (CMS) implemented the Comprehensive Error Rate Testing (CERT) program to measure improper payments in the Medicare...

  16. Experiences with alanine dosimetry in afterloading brachytherapy

    International Nuclear Information System (INIS)

    At the present, the most commonly used dosimetry for radiotherapy applications are ionisation chambers and thermoluminescent dosimeters (TLD). However, there are some undesirable characteristics of these dosimetry systems, such as large detection volume (ionisation chamber) as well as fading of the radiation induced signal with time and destructive readout (TLG). The present study is an investigation into the use of the alanine/ESR dosimetry in fractionated afterloading brachytherapy during the whole radiotherapy course. There are some qualities which make alanine dosimetry attractive. These are the linear energy response, low fading under standard conditions, and the nondestructive readout. Thus the alanine dosimetry makes possible cumulative dose measurements during the radiotherapy course and an archival storage. By ionizing radiation (gamma, e, n, p, charged particles) free radicals (unpaired electrons) are produced in the amino acid alanine. The continuous wave electron spin resonance (ESR) spectroscopy is used to determine the number of free radicals, which is proportional to the absorbed dose and the alanine content of the dosimeter. The ESR measurements were made at room temperature using a Bruker EPR analyzer EMS-104. The dosimeters used in the test are alanine pellets (23.72 mg weight, 4.9 mm diameter, 1 mm height) as well as flexible alanine film dosimeters (thickness about 500 μm). The dosimeters consist of a blend of L-alpha-alanine and a binder. The alanine content of the pellets and the film dosimeters is about 88 % and 50 % by weight, respectively. The dosimeters for the calculation of the dose-effect-relationship were irradiated at the Physical-Technical Bundesanstalt in Braunschweig by a standard 60Co source. The maximum deviation from the calculated linear function is about 0.12 Gy in the dose range up to 80 Gy. The goal of medical applications was the superficial dose measurement in afterloading brachytherapy during the radiotherapy course in

  17. The application of Geant4 simulation code for brachytherapy treatment

    CERN Document Server

    Agostinelli, S; Garelli, S; Paoli, G; Nieminen, P; Pia, M G

    2000-01-01

    Brachytherapy is a radiotherapeutic modality that makes use of radionuclides to deliver a high radiation dose to a well-defined volume while sparing surrounding healthy structures. At the National Institute for Cancer Research of Genova a High Dose Rate remote afterloading system provides Ir(192) endocavitary brachytherapy treatments. We studied the possibility to use the Geant4 Monte Carlo simulation toolkit in brachytherapy for calculation of complex physical parameters, not directly available by experiment al measurements, used in treatment planning dose deposition models.

  18. Human Error Identification of Operator in Digital Main Control Room of NPPs Based on Simulator Experiment%基于模拟机实验的核电厂数字化主控室人因失误辨识

    Institute of Scientific and Technical Information of China (English)

    李鹏程; 张力; 戴立操; 胡鸿

    2014-01-01

    In order to identify main human error modes of operator in digital main con‐trol room of nuclear power plant (NPP) ,the main cognitive functions of operator were identified based on field observation ,operator interview ,and cognitive activity analysis . The classification framework of human error was established on the basis of identified cognitive functions of operator .The main human error modes of operator were identified by the full‐size simulator experiment ,and the causes leading to human errors were ana‐lyzed .It provides theoretical support for improving operators’ reliability ,reducing and preventing human errors .%为了识别核电厂数字化主控室中操纵员的主要人因失误模式,本文基于现场观察、操纵员访谈以及认知行为分析识别操纵员的主要认知功能,并据此建立了人因失误分类体系。在此基础上,通过模拟机实验识别数字化主控室操纵员的主要人因失误模式及其原因,为提高核电厂操纵员的行为可靠性、人因失误的减少和预防提供理论支持。

  19. Dosimetric characterization and output verification for conical brachytherapy surface applicators. Part I. Electronic brachytherapy source

    International Nuclear Information System (INIS)

    Purpose: Historically, treatment of malignant surface lesions has been achieved with linear accelerator based electron beams or superficial x-ray beams. Recent developments in the field of brachytherapy now allow for the treatment of surface lesions with specialized conical applicators placed directly on the lesion. Applicators are available for use with high dose rate (HDR)192Ir sources, as well as electronic brachytherapy sources. Part I of this paper will discuss the applicators used with electronic brachytherapy sources; Part II will discuss those used with HDR 192Ir sources. Although the use of these applicators has gained in popularity, the dosimetric characteristics including depth dose and surface dose distributions have not been independently verified. Additionally, there is no recognized method of output verification for quality assurance procedures with applicators like these. Existing dosimetry protocols available from the AAPM bookend the cross-over characteristics of a traditional brachytherapy source (as described by Task Group 43) being implemented as a low-energy superficial x-ray beam (as described by Task Group 61) as observed with the surface applicators of interest. Methods: This work aims to create a cohesive method of output verification that can be used to determine the dose at the treatment surface as part of a quality assurance/commissioning process for surface applicators used with HDR electronic brachytherapy sources (Part I) and192Ir sources (Part II). Air-kerma rate measurements for the electronic brachytherapy sources were completed with an Attix Free-Air Chamber, as well as several models of small-volume ionization chambers to obtain an air-kerma rate at the treatment surface for each applicator. Correction factors were calculated using MCNP5 and EGSnrc Monte Carlo codes in order to determine an applicator-specific absorbed dose to water at the treatment surface from the measured air-kerma rate. Additionally, relative dose

  20. Random errors in egocentric networks.

    Science.gov (United States)

    Almquist, Zack W

    2012-10-01

    The systematic errors that are induced by a combination of human memory limitations and common survey design and implementation have long been studied in the context of egocentric networks. Despite this, little if any work exists in the area of random error analysis on these same networks; this paper offers a perspective on the effects of random errors on egonet analysis, as well as the effects of using egonet measures as independent predictors in linear models. We explore the effects of false-positive and false-negative error in egocentric networks on both standard network measures and on linear models through simulation analysis on a ground truth egocentric network sample based on facebook-friendships. Results show that 5-20% error rates, which are consistent with error rates known to occur in ego network data, can cause serious misestimation of network properties and regression parameters. PMID:23878412

  1. The EQUAL-ESTRO audit on geometric reconstruction techniques in brachytherapy

    International Nuclear Information System (INIS)

    Background and purpose: A geometric check procedure of the reconstruction techniques used in brachytherapy treatment planning systems was developed by the EQUAL (European Quality Laboratory) Laboratory in the framework of the ESTRO's (European Society for Therapeutic Radiology and Oncology) project 'ESQUIRE' (Education Science and QUality assurance In Radiotherapy in Europe [Baumann M, Brada M. Towards equity in turbulent Europe ESTRO, European cooperation and the European Commission. Radiother Oncol 2005;75:251-2. Heeren G. The bright but ephemeral life of a rainbow. A chronical of seventeen years of intensive ESTRO-EU cooperation. Radiother Oncol 2005;75:253-7]) by the task group Braphyqs (Brachytherapy physics quality system). Patients and methods: The check is performed by using the so-called 'Baltas' phantom, mailed to the participating centres in order to check the local technique of geometric reconstruction used in dose calculation. Results: To validate the procedures, the check was first tested among the members of the Braphyqs Network. Since November 2002, the system is open to other centres. Until now 152 reconstructions have been checked. Eighty-six percent of the results were within an acceptance level after the first check. For the remaining 14%, a second check has been proposed. The results of the re-checks are in most cases within an acceptance level, except for 2% of the reconstructions. Conclusions: The geometric check is available from the EQUAL Laboratory for all the brachytherapy centres. The decrease of the deviations observed between the two checks demonstrates the importance of this kind of external audit as some errors were revealed, which were not discovered before with techniques used in clinical quality control routines

  2. Novel tools for stepping source brachytherapy treatment planning: Enhanced geometrical optimization and interactive inverse planning

    Energy Technology Data Exchange (ETDEWEB)

    Dinkla, Anna M., E-mail: a.m.dinkla@amc.uva.nl; Laarse, Rob van der; Koedooder, Kees; Petra Kok, H.; Wieringen, Niek van; Pieters, Bradley R.; Bel, Arjan [Department of Radiation Oncology, Academic Medical Center Amsterdam, Meibergdreef 9, Amsterdam 1105 AZ (Netherlands)

    2015-01-15

    Purpose: Dose optimization for stepping source brachytherapy can nowadays be performed using automated inverse algorithms. Although much quicker than graphical optimization, an experienced treatment planner is required for both methods. With automated inverse algorithms, the procedure to achieve the desired dose distribution is often based on trial-and-error. Methods: A new approach for stepping source prostate brachytherapy treatment planning was developed as a quick and user-friendly alternative. This approach consists of the combined use of two novel tools: Enhanced geometrical optimization (EGO) and interactive inverse planning (IIP). EGO is an extended version of the common geometrical optimization method and is applied to create a dose distribution as homogeneous as possible. With the second tool, IIP, this dose distribution is tailored to a specific patient anatomy by interactively changing the highest and lowest dose on the contours. Results: The combined use of EGO–IIP was evaluated on 24 prostate cancer patients, by having an inexperienced user create treatment plans, compliant to clinical dose objectives. This user was able to create dose plans of 24 patients in an average time of 4.4 min/patient. An experienced treatment planner without extensive training in EGO–IIP also created 24 plans. The resulting dose-volume histogram parameters were comparable to the clinical plans and showed high conformance to clinical standards. Conclusions: Even for an inexperienced user, treatment planning with EGO–IIP for stepping source prostate brachytherapy is feasible as an alternative to current optimization algorithms, offering speed, simplicity for the user, and local control of the dose levels.

  3. Novel tools for stepping source brachytherapy treatment planning: Enhanced geometrical optimization and interactive inverse planning

    International Nuclear Information System (INIS)

    Purpose: Dose optimization for stepping source brachytherapy can nowadays be performed using automated inverse algorithms. Although much quicker than graphical optimization, an experienced treatment planner is required for both methods. With automated inverse algorithms, the procedure to achieve the desired dose distribution is often based on trial-and-error. Methods: A new approach for stepping source prostate brachytherapy treatment planning was developed as a quick and user-friendly alternative. This approach consists of the combined use of two novel tools: Enhanced geometrical optimization (EGO) and interactive inverse planning (IIP). EGO is an extended version of the common geometrical optimization method and is applied to create a dose distribution as homogeneous as possible. With the second tool, IIP, this dose distribution is tailored to a specific patient anatomy by interactively changing the highest and lowest dose on the contours. Results: The combined use of EGO–IIP was evaluated on 24 prostate cancer patients, by having an inexperienced user create treatment plans, compliant to clinical dose objectives. This user was able to create dose plans of 24 patients in an average time of 4.4 min/patient. An experienced treatment planner without extensive training in EGO–IIP also created 24 plans. The resulting dose-volume histogram parameters were comparable to the clinical plans and showed high conformance to clinical standards. Conclusions: Even for an inexperienced user, treatment planning with EGO–IIP for stepping source prostate brachytherapy is feasible as an alternative to current optimization algorithms, offering speed, simplicity for the user, and local control of the dose levels

  4. Evaluation of resins for use in brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Luiz Claudio F.M. Garcia; Ferraz, Wilmar Barbosa; Chrcanovic, Bruno Ramos; Santos, Ana Maria M., E-mail: ferrazw@cdtn.b, E-mail: amms@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Brachytherapy is an advanced cancer treatment where radioactive seeds or sources are placed near or directly into the tumor thus reducing the radiation exposure in the surrounding healthy tissues. Prostate cancer can be treated with interstitial brachytherapy in initial stage of the disease in which tiny radioactive seeds with cylindrical geometry are used. Several kinds of seeds have been developed in order to obtain a better dose distribution around them and with a lower cost manufacturing. These seeds consist of an encapsulation, a radionuclide carrier, and X-ray marker. Among the materials that have potential for innovation in the construction of seeds, biocompatible resins appear as an important option. In this paper, we present some characterization results with Fourier transform infrared spectroscopic (FTIR) and ultraviolet-visible spectroscopy (UV-vis) performed on two types of resins in which curing temperatures for each one were varied as also the results of coatings with these resins under titanium substrates. Interactions of these resins in contact with the simulated body fluid were evaluated by atomic force microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. (author)

  5. Samarium-145: a new brachytherapy source

    International Nuclear Information System (INIS)

    A new radiation source has been produced for brachytherapy, with radiation energies slightly above those of 125I, and a Tsub(1/2) of 340 d. This source, 145Sm, is produced by neutron irradiation of 144Sm (96.5% enriched). Decay is by electron capture with 140 K x-rays per 100 disintergrations in the energy region between 38-45 keV, plus 13 γ-rays at 61 keV. These sources are encapsulated in Ti tubes, approx. 0.8 mm x 4.5 mm, and have been developed for temporary implantation in brain and ocular tumours. The 38-61 keV photons should make such sources easy to shield, while providing a dose distribution from source arrays somewhat more homogeneous than that from 125I. In addition, the 340 d half life of 145Sm permits its use for times significantly longer than that of 60 d 125I. While the 145Sm sources have been designed primarily for implantation in a brain tumour, they should be useful for almost any conventional brachytherapy application. (author)

  6. Quality assurance for high dose rate brachytherapy treatment planning optimization: using a simple optimization to verify a complex optimization

    International Nuclear Information System (INIS)

    As dose optimization for high dose rate brachytherapy becomes more complex, it becomes increasingly important to have a means of verifying that optimization results are reasonable. A method is presented for using a simple optimization as quality assurance for the more complex optimization algorithms typically found in commercial brachytherapy treatment planning systems. Quality assurance tests may be performed during commissioning, at regular intervals, and/or on a patient specific basis. A simple optimization method is provided that optimizes conformal target coverage using an exact, variance-based, algebraic approach. Metrics such as dose volume histogram, conformality index, and total reference air kerma agree closely between simple and complex optimizations for breast, cervix, prostate, and planar applicators. The simple optimization is shown to be a sensitive measure for identifying failures in a commercial treatment planning system that are possibly due to operator error or weaknesses in planning system optimization algorithms. Results from the simple optimization are surprisingly similar to the results from a more complex, commercial optimization for several clinical applications. This suggests that there are only modest gains to be made from making brachytherapy optimization more complex. The improvements expected from sophisticated linear optimizations, such as PARETO methods, will largely be in making systems more user friendly and efficient, rather than in finding dramatically better source strength distributions. (paper)

  7. Manual on brachytherapy. Incorporating: Applications guide, procedures guide, basics guide

    International Nuclear Information System (INIS)

    In addition to a basic guide to the principles of the production of ionizing radiation and to methods of radiation protection and dosimetry, this booklet includes information about radiation protection procedures for brachytherapy

  8. Image-Based Brachytherapy for the Treatment of Cervical Cancer

    International Nuclear Information System (INIS)

    Cervical cancer is a disease that requires considerable multidisciplinary coordination of care and labor in order to maximize tumor control and survival while minimizing treatment-related toxicity. As with external beam radiation therapy, the use of advanced imaging and 3-dimensional treatment planning has generated a paradigm shift in the delivery of brachytherapy for the treatment of cervical cancer. The use of image-based brachytherapy, most commonly with magnetic resonance imaging (MRI), requires additional attention and effort by the treating physician to prescribe dose to the proper volume and account for adjacent organs at risk. This represents a dramatic change from the classic Manchester approach of orthogonal radiographic images and prescribing dose to point A. We reviewed the history and currently evolving data and recommendations for the clinical use of image-based brachytherapy with an emphasis on MRI-based brachytherapy

  9. Nursing intervention in gynecologic brachytherapy under general anesthesia

    International Nuclear Information System (INIS)

    We reconsidered our nursing intervention in gynecologic intracavitary brachytherapy as general anesthesia was introduced. We recognized that safety, comfort, privacy protection and relief of anxiety of the patients were important points for nursing with corporation of other medical staffs. (author)

  10. Image-Based Brachytherapy for the Treatment of Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Harkenrider, Matthew M., E-mail: mharkenrider@lumc.edu; Alite, Fiori; Silva, Scott R.; Small, William

    2015-07-15

    Cervical cancer is a disease that requires considerable multidisciplinary coordination of care and labor in order to maximize tumor control and survival while minimizing treatment-related toxicity. As with external beam radiation therapy, the use of advanced imaging and 3-dimensional treatment planning has generated a paradigm shift in the delivery of brachytherapy for the treatment of cervical cancer. The use of image-based brachytherapy, most commonly with magnetic resonance imaging (MRI), requires additional attention and effort by the treating physician to prescribe dose to the proper volume and account for adjacent organs at risk. This represents a dramatic change from the classic Manchester approach of orthogonal radiographic images and prescribing dose to point A. We reviewed the history and currently evolving data and recommendations for the clinical use of image-based brachytherapy with an emphasis on MRI-based brachytherapy.

  11. Brachytherapy in thetreatment of the oral and oropharyngeal cancer

    Directory of Open Access Journals (Sweden)

    A. M. Zhumankulov

    2015-01-01

    Full Text Available Background. One of the methods of radiotherapy of malignant tumors of oral cavity and oropharyngeal region today is interstitial radiation therapy – brachytherapy, allowing you to create the optimum dose of irradiation to the tumor, necessary for its destruction, without severe radiation reactions in the surrounding tissues unchanged. Brachytherapy has the following advantages: high precision – the ability of the local summarization of high single doses in a limited volume of tissue; good tolerability; a short time of treatment. At this time, brachytherapy is the method of choice used as palliative therapy and as a component of radical treatment.Objective: The purpose of this article is a literature review about the latest achievements of interstitial brachytherapy in malignant tumors of the oral cavity and oropharynx.

  12. Radiotherapy and Brachytherapy : Proceedings of the NATO Advanced Study Institute on Physics of Modern Radiotherapy & Brachytherapy

    CERN Document Server

    Lemoigne, Yves

    2009-01-01

    This volume collects a series of lectures presented at the tenth ESI School held at Archamps (FR) in November 2007 and dedicated to radiotherapy and brachytherapy. The lectures focus on the multiple facets of radiotherapy in general, including external radiotherapy (often called teletherapy) as well as internal radiotherapy (called brachytherapy). Radiotherapy strategy and dose management as well as the decisive role of digital imaging in the associated clinical practice are developed in several articles. Grouped under the discipline of Conformal Radiotherapy (CRT), numerous modern techniques, from Multi-Leaf Collimators (MLC) to Intensity Modulated RadioTherapy (IMRT), are explained in detail. The importance of treatment planning based upon patient data from digital imaging (Computed Tomography) is also underlined. Finally, despite the quasi- totality of patients being presently treated with gamma and X-rays, novel powerful tools are emerging using proton and light ions (like carbon ions) beams, bound to bec...

  13. Brachytherapy. Pulsed dose rate brachytherapy - Radiation protection: medical sheet ED 4250

    International Nuclear Information System (INIS)

    After having indicated the required authorization to implement brachytherapy techniques, this document presents the various aspects and measures related to radiation protection when performing pulsed-dose-rate brachytherapy treatments. It presents the concerned personnel, describes the operational process, indicates the associated hazards and the risk related to ionizing radiation, and describes how the risk is to be assessed and how exposure levels are to be determined (elements of risk assessment, delimitation of controlled and monitored areas, personnel classification, and choice of the dose monitoring method). It describes the various components of a risk management strategy (risk reduction, technical measures regarding the installation and the personnel, training and information, prevention and medical monitoring). It briefly presents how risk management is to be assessed, and mentions other related risks (biological risk, handling and posture, handling of heavy loads, mental workload, chemical risk)

  14. Evaluation of an active magnetic resonance tracking system for interstitial brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: wwang21@partners.org [Department of Radiology, Brigham and Women’s Hospital, Boston, Massachusetts 02115 and Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Viswanathan, Akila N.; Damato, Antonio L.; Cormack, Robert A. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Chen, Yue; Tse, Zion [Department of Engineering, The University of Georgia, Athens, Georgia 30602 (United States); Pan, Li [Siemens Healthcare USA, Baltimore, Maryland 21287 (United States); Tokuda, Junichi; Schmidt, Ehud J. [Department of Radiology, Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Seethamraju, Ravi T. [Siemens Healthcare USA, Boston, Massachusetts 02115 (United States); Dumoulin, Charles L. [Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio 45229 (United States)

    2015-12-15

    Purpose: In gynecologic cancers, magnetic resonance (MR) imaging is the modality of choice for visualizing tumors and their surroundings because of superior soft-tissue contrast. Real-time MR guidance of catheter placement in interstitial brachytherapy facilitates target coverage, and would be further improved by providing intraprocedural estimates of dosimetric coverage. A major obstacle to intraprocedural dosimetry is the time needed for catheter trajectory reconstruction. Herein the authors evaluate an active MR tracking (MRTR) system which provides rapid catheter tip localization and trajectory reconstruction. The authors assess the reliability and spatial accuracy of the MRTR system in comparison to standard catheter digitization using magnetic resonance imaging (MRI) and CT. Methods: The MRTR system includes a stylet with microcoils mounted on its shaft, which can be inserted into brachytherapy catheters and tracked by a dedicated MRTR sequence. Catheter tip localization errors of the MRTR system and their dependence on catheter locations and orientation inside the MR scanner were quantified with a water phantom. The distances between the tracked tip positions of the MRTR stylet and the predefined ground-truth tip positions were calculated for measurements performed at seven locations and with nine orientations. To evaluate catheter trajectory reconstruction, fifteen brachytherapy catheters were placed into a gel phantom with an embedded catheter fixation framework, with parallel or crossed paths. The MRTR stylet was then inserted sequentially into each catheter. During the removal of the MRTR stylet from within each catheter, a MRTR measurement was performed at 40 Hz to acquire the instantaneous stylet tip position, resulting in a series of three-dimensional (3D) positions along the catheter’s trajectory. A 3D polynomial curve was fit to the tracked positions for each catheter, and equally spaced dwell points were then generated along the curve. High

  15. Evaluation of an active magnetic resonance tracking system for interstitial brachytherapy

    International Nuclear Information System (INIS)

    Purpose: In gynecologic cancers, magnetic resonance (MR) imaging is the modality of choice for visualizing tumors and their surroundings because of superior soft-tissue contrast. Real-time MR guidance of catheter placement in interstitial brachytherapy facilitates target coverage, and would be further improved by providing intraprocedural estimates of dosimetric coverage. A major obstacle to intraprocedural dosimetry is the time needed for catheter trajectory reconstruction. Herein the authors evaluate an active MR tracking (MRTR) system which provides rapid catheter tip localization and trajectory reconstruction. The authors assess the reliability and spatial accuracy of the MRTR system in comparison to standard catheter digitization using magnetic resonance imaging (MRI) and CT. Methods: The MRTR system includes a stylet with microcoils mounted on its shaft, which can be inserted into brachytherapy catheters and tracked by a dedicated MRTR sequence. Catheter tip localization errors of the MRTR system and their dependence on catheter locations and orientation inside the MR scanner were quantified with a water phantom. The distances between the tracked tip positions of the MRTR stylet and the predefined ground-truth tip positions were calculated for measurements performed at seven locations and with nine orientations. To evaluate catheter trajectory reconstruction, fifteen brachytherapy catheters were placed into a gel phantom with an embedded catheter fixation framework, with parallel or crossed paths. The MRTR stylet was then inserted sequentially into each catheter. During the removal of the MRTR stylet from within each catheter, a MRTR measurement was performed at 40 Hz to acquire the instantaneous stylet tip position, resulting in a series of three-dimensional (3D) positions along the catheter’s trajectory. A 3D polynomial curve was fit to the tracked positions for each catheter, and equally spaced dwell points were then generated along the curve. High

  16. Parameterization of brachytherapy source phase space file for Monte Carlo-based clinical brachytherapy dose calculation

    International Nuclear Information System (INIS)

    A common approach to implementing the Monte Carlo method for the calculation of brachytherapy radiation dose deposition is to use a phase space file containing information on particles emitted from a brachytherapy source. However, the loading of the phase space file during the dose calculation consumes a large amount of computer random access memory, imposing a higher requirement for computer hardware. In this study, we propose a method to parameterize the information (e.g., particle location, direction and energy) stored in the phase space file by using several probability distributions. This method was implemented for dose calculations of a commercial Ir-192 high dose rate source. Dose calculation accuracy of the parameterized source was compared to the results observed using the full phase space file in a simple water phantom and in a clinical breast cancer case. The results showed the parameterized source at a size of 200 kB was as accurate as the phase space file represented source of 1.1 GB. By using the parameterized source representation, a compact Monte Carlo job can be designed, which allows an easy setup for parallel computing in brachytherapy planning. (paper)

  17. Parameterization of brachytherapy source phase space file for Monte Carlo-based clinical brachytherapy dose calculation

    Science.gov (United States)

    Zhang, M.; Zou, W.; Chen, T.; Kim, L.; Khan, A.; Haffty, B.; Yue, N. J.

    2014-01-01

    A common approach to implementing the Monte Carlo method for the calculation of brachytherapy radiation dose deposition is to use a phase space file containing information on particles emitted from a brachytherapy source. However, the loading of the phase space file during the dose calculation consumes a large amount of computer random access memory, imposing a higher requirement for computer hardware. In this study, we propose a method to parameterize the information (e.g., particle location, direction and energy) stored in the phase space file by using several probability distributions. This method was implemented for dose calculations of a commercial Ir-192 high dose rate source. Dose calculation accuracy of the parameterized source was compared to the results observed using the full phase space file in a simple water phantom and in a clinical breast cancer case. The results showed the parameterized source at a size of 200 kB was as accurate as the phase space file represented source of 1.1 GB. By using the parameterized source representation, a compact Monte Carlo job can be designed, which allows an easy setup for parallel computing in brachytherapy planning.

  18. Intraluminal brachytherapy in the treatment of bile duct carcinoma

    International Nuclear Information System (INIS)

    Patients with carcinoma of the biliary tract have a poor prognosis because the disease is often unresectable at diagnosis. Intraluminal brachytherapy has been reported as an effective treatment for localized cholangiocarcinoma of the biliary tract. The purpose of our study was to analyse the survival of patients treated with brachytherapy and make some recommendations regarding its use. Fifteen patients underwent brachytherapy via a trans-hepatic approach at the Royal Prince Alfred Hospital from 1983 to 1993. Eleven patients had low-dose rate brachytherapy and four patients had high-dose rate treatment. There were nine males and six females. The median age was 64 years. Other treatment included bypass procedures in two patients, endoscopic stents in 14 patients and external beam irradiation in one patient. The median survival was 12.5 months and 47% of the patients survived 1 year. The only complication reported was cholangitis which was seen in one patient. There did not seem to be any difference in survival or complications between low- and high-dose rate brachytherapy. It is concluded that the addition of intraluminal brachytherapy after biliary drainage prolongs survival and is a safe and effective treatment, but patients still have a high rate of local failure, and further studies will be needed to address this problem. (authors)

  19. Medication errors: prescribing faults and prescription errors

    OpenAIRE

    Velo, Giampaolo P; Minuz, Pietro

    2009-01-01

    Medication errors are common in general practice and in hospitals. Both errors in the act of writing (prescription errors) and prescribing faults due to erroneous medical decisions can result in harm to patients.Any step in the prescribing process can generate errors. Slips, lapses, or mistakes are sources of errors, as in unintended omissions in the transcription of drugs. Faults in dose selection, omitted transcription, and poor handwriting are common.Inadequate knowledge or competence and ...

  20. An image-guidance system for dynamic dose calculation in prostate brachytherapy using ultrasound and fluoroscopy

    International Nuclear Information System (INIS)

    Purpose: Brachytherapy is a standard option of care for prostate cancer patients but may be improved by dynamic dose calculation based on localized seed positions. The American Brachytherapy Society states that the major current limitation of intraoperative treatment planning is the inability to localize the seeds in relation to the prostate. An image-guidance system was therefore developed to localize seeds for dynamic dose calculation. Methods: The proposed system is based on transrectal ultrasound (TRUS) and mobile C-arm fluoroscopy, while using a simple fiducial with seed-like markers to compute pose from the nonencoded C-arm. Three or more fluoroscopic images and an ultrasound volume are acquired and processed by a pipeline of algorithms: (1) seed segmentation, (2) fiducial detection with pose estimation, (3) seed matching with reconstruction, and (4) fluoroscopy-to-TRUS registration. Results: The system was evaluated on ten phantom cases, resulting in an overall mean error of 1.3 mm. The system was also tested on 37 patients and each algorithm was evaluated. Seed segmentation resulted in a 1% false negative rate and 2% false positive rate. Fiducial detection with pose estimation resulted in a 98% detection rate. Seed matching with reconstruction had a mean error of 0.4 mm. Fluoroscopy-to-TRUS registration had a mean error of 1.3 mm. Moreover, a comparison of dose calculations between the authors’ intraoperative method and an independent postoperative method shows a small difference of 7% and 2% forD90 and V100, respectively. Finally, the system demonstrated the ability to detect cold spots and required a total processing time of approximately 1 min. Conclusions: The proposed image-guidance system is the first practical approach to dynamic dose calculation, outperforming earlier solutions in terms of robustness, ease of use, and functional completeness

  1. Radiation-induced light in optical fibers and plastic scintillators: Application to brachytherapy dosimetry

    International Nuclear Information System (INIS)

    A small plastic scintillator bonded to an optical fiber has several characteristics that make it promising as a brachytherapy dosimeter. In these dosimeters, scintillation light represents signal, whereas Cerenkov and luminescence light from the optical fiber stem is noise that must be subtracted. The dosimeter accuracy can be improved by optically filtering part of the fiber stem light. Spectral measurements were performed to guide the choice of scintillator, fiber, and filter. Spectral signatures and total luminescence of three scintillators and five different silica optical fibers, excited by a 8 Ci 192Ir source, were measured. The total radiation-induced light from the various optical fibers differed by up to a factor of 5.6. The percentage of fiber-produced light due to luminescence varied between 15 and 79%. A fiber with weak emission was used in the dosimeter with BC408S, a scintillator with minimum emission wavelength of 400 nm. A 400-nm cutoff UV filter gave a factor of two increase in signal-to-noise. The dosimeter response was linear for dose rates varying by at least three orders of magnitude, representing source-to-probe distances of 0.2--10 cm. Measurement errors of the dosimeter compare favorably with other brachytherapy dosimeters

  2. A simplified analytical dose calculation algorithm accounting for tissue heterogeneity for low-energy brachytherapy sources.

    Science.gov (United States)

    Mashouf, Shahram; Lechtman, Eli; Beaulieu, Luc; Verhaegen, Frank; Keller, Brian M; Ravi, Ananth; Pignol, Jean-Philippe

    2013-09-21

    The American Association of Physicists in Medicine Task Group No. 43 (AAPM TG-43) formalism is the standard for seeds brachytherapy dose calculation. But for breast seed implants, Monte Carlo simulations reveal large errors due to tissue heterogeneity. Since TG-43 includes several factors to account for source geometry, anisotropy and strength, we propose an additional correction factor, called the inhomogeneity correction factor (ICF), accounting for tissue heterogeneity for Pd-103 brachytherapy. This correction factor is calculated as a function of the media linear attenuation coefficient and mass energy absorption coefficient, and it is independent of the source internal structure. Ultimately the dose in heterogeneous media can be calculated as a product of dose in water as calculated by TG-43 protocol times the ICF. To validate the ICF methodology, dose absorbed in spherical phantoms with large tissue heterogeneities was compared using the TG-43 formalism corrected for heterogeneity versus Monte Carlo simulations. The agreement between Monte Carlo simulations and the ICF method remained within 5% in soft tissues up to several centimeters from a Pd-103 source. Compared to Monte Carlo, the ICF methods can easily be integrated into a clinical treatment planning system and it does not require the detailed internal structure of the source or the photon phase-space. PMID:23965939

  3. Detection and correction of patient movement in prostate brachytherapy seed reconstruction

    Science.gov (United States)

    Lam, Steve T.; Cho, Paul S.; Marks, Robert J., II; Narayanan, Sreeram

    2005-05-01

    Intraoperative dosimetry of prostate brachytherapy can help optimize the dose distribution and potentially improve clinical outcome. Evaluation of dose distribution during the seed implant procedure requires the knowledge of 3D seed coordinates. Fluoroscopy-based seed localization is a viable option. From three x-ray projections obtained at different gantry angles, 3D seed positions can be determined. However, when local anaesthesia is used for prostate brachytherapy, the patient movement during fluoroscopy image capture becomes a practical problem. If uncorrected, the errors introduced by patient motion between image captures would cause seed mismatches. Subsequently, the seed reconstruction algorithm would either fail to reconstruct or yield erroneous results. We have developed an algorithm that permits detection and correction of patient movement that may occur between fluoroscopy image captures. The patient movement is decomposed into translational shifts along the tabletop and rotation about an axis perpendicular to the tabletop. The property of spatial invariance of the co-planar imaging geometry is used for lateral movement correction. Cranio-caudal movement is corrected by analysing the perspective invariance along the x-ray axis. Rotation is estimated by an iterative method. The method can detect and correct for the range of patient movement commonly seen in the clinical environment. The algorithm has been implemented for routine clinical use as the preprocessing step for seed reconstruction.

  4. Predictors of Metastatic Disease After Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To identify predictors of metastatic disease after brachytherapy treatment for prostate cancer. Methods and Materials: All patients who received either brachytherapy alone (implant) or brachytherapy in combination with external beam radiation therapy for treatment of localized prostate cancer at The Mount Sinai Hospital between June 1990 and March 2007 with a minimum follow-up of 2 years were included. Univariate and multivariable analyses were performed on the following variables: risk group, Gleason score (GS), clinical T stage, pretreatment prostate-specific antigen level, post-treatment prostate-specific antigen doubling time (PSA-DT), treatment type (implant vs. implant plus external beam radiation therapy), treatment era, total biological effective dose, use of androgen deprivation therapy, age at diagnosis, and race. PSA-DT was analyzed in the following ordinate groups: 0 to 90 days, 91 to 180 days, 180 to 360 days, and greater than 360 days. Results: We included 1,887 patients in this study. Metastases developed in 47 of these patients. The 10-year freedom from distant metastasis (FFDM) rate for the entire population was 95.1%. Median follow-up was 6 years (range, 2–15 years). The only two significant predictors of metastatic disease by multivariable analyses were GS and PSA-DT (p < 0.001 for both variables). Estimated 10-year FFDM rates for GS of 6 or less, GS of 7, and GS of 8 or greater were 97.9%, 94.3%, and 76.1%, respectively (p < 0.001). Estimated FFDM rates for PSA-DT of 0 to 90 days, 91 to 180 days, 181 to 360 days, and greater than 360 days were 17.5%, 67.9%, 74%, and 94.8%, respectively (p < 0.001). Estimated 10-year FFDM rates for the low-, intermediate-, and high-risk groups were 98.6%, 96.2%, and 86.7%, respectively. A demographic shift to patients presenting with higher-grade disease in more recent years was observed. Conclusions: GS and post-treatment PSA-DT are both statistically significant independent predictors of metastatic

  5. WE-A-17A-03: Catheter Digitization in High-Dose-Rate Brachytherapy with the Assistance of An Electromagnetic (EM) Tracking System

    International Nuclear Information System (INIS)

    Purpose: To investigate the use of a system using EM tracking, postprocessing and error-detection algorithms for measuring brachytherapy catheter locations and for detecting errors and resolving uncertainties in treatment-planning catheter digitization. Methods: An EM tracker was used to localize 13 catheters in a clinical surface applicator (A) and 15 catheters inserted into a phantom (B). Two pairs of catheters in (B) crossed paths at a distance <2 mm, producing an undistinguishable catheter artifact in that location. EM data was post-processed for noise reduction and reformatted to provide the dwell location configuration. CT-based digitization was automatically extracted from the brachytherapy plan DICOM files (CT). EM dwell digitization error was characterized in terms of the average and maximum distance between corresponding EM and CT dwells per catheter. The error detection rate (detected errors / all errors) was calculated for 3 types of errors: swap of two catheter numbers; incorrect catheter number identification superior to the closest position between two catheters (mix); and catheter-tip shift. Results: The averages ± 1 standard deviation of the average and maximum registration error per catheter were 1.9±0.7 mm and 3.0±1.1 mm for (A) and 1.6±0.6 mm and 2.7±0.8 mm for (B). The error detection rate was 100% (A and B) for swap errors, mix errors, and shift >4.5 mm (A) and >5.5 mm (B); errors were detected for shifts on average >2.0 mm (A) and >2.4 mm (B). Both mix errors associated with undistinguishable catheter artifacts were detected and at least one of the involved catheters was identified. Conclusion: We demonstrated the use of an EM tracking system for localization of brachytherapy catheters, detection of digitization errors and resolution of undistinguishable catheter artifacts. Automatic digitization may be possible with a registration between the imaging and the EM frame of reference. Research funded by the Kaye Family Award 2012

  6. WE-A-17A-03: Catheter Digitization in High-Dose-Rate Brachytherapy with the Assistance of An Electromagnetic (EM) Tracking System

    Energy Technology Data Exchange (ETDEWEB)

    Damato, AL; Bhagwat, MS; Buzurovic, I; Devlin, PM; Friesen, S; Hansen, JL; Kapur, T; Lee, LJ; Mehrtash, A; Nguyen, PL; O' Farrell, D; Wang, W; Viswanathan, AN; Cormack, RA [Brigham and Women' s Hospital, Boston, MA (United States)

    2014-06-15

    Purpose: To investigate the use of a system using EM tracking, postprocessing and error-detection algorithms for measuring brachytherapy catheter locations and for detecting errors and resolving uncertainties in treatment-planning catheter digitization. Methods: An EM tracker was used to localize 13 catheters in a clinical surface applicator (A) and 15 catheters inserted into a phantom (B). Two pairs of catheters in (B) crossed paths at a distance <2 mm, producing an undistinguishable catheter artifact in that location. EM data was post-processed for noise reduction and reformatted to provide the dwell location configuration. CT-based digitization was automatically extracted from the brachytherapy plan DICOM files (CT). EM dwell digitization error was characterized in terms of the average and maximum distance between corresponding EM and CT dwells per catheter. The error detection rate (detected errors / all errors) was calculated for 3 types of errors: swap of two catheter numbers; incorrect catheter number identification superior to the closest position between two catheters (mix); and catheter-tip shift. Results: The averages ± 1 standard deviation of the average and maximum registration error per catheter were 1.9±0.7 mm and 3.0±1.1 mm for (A) and 1.6±0.6 mm and 2.7±0.8 mm for (B). The error detection rate was 100% (A and B) for swap errors, mix errors, and shift >4.5 mm (A) and >5.5 mm (B); errors were detected for shifts on average >2.0 mm (A) and >2.4 mm (B). Both mix errors associated with undistinguishable catheter artifacts were detected and at least one of the involved catheters was identified. Conclusion: We demonstrated the use of an EM tracking system for localization of brachytherapy catheters, detection of digitization errors and resolution of undistinguishable catheter artifacts. Automatic digitization may be possible with a registration between the imaging and the EM frame of reference. Research funded by the Kaye Family Award 2012.

  7. Automated treatment planning engine for prostate seed implant brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To develop a computer-intelligent planning engine for automated treatment planning and optimization of ultrasound- and template-guided prostate seed implants. Methods and Materials: The genetic algorithm was modified to reflect the 2D nature of the implantation template. A multi-objective decision scheme was used to rank competing solutions, taking into account dose uniformity and conformity to the planning target volume (PTV), dose-sparing of the urethra and the rectum, and the sensitivity of the resulting dosimetry to seed misplacement. Optimized treatment plans were evaluated using selected dosimetric quantifiers, dose-volume histogram (DVH), and sensitivity analysis based on simulated seed placement errors. These dosimetric planning components were integrated into the Prostate Implant Planning Engine for Radiotherapy (PIPER). Results: PIPER has been used to produce a variety of plans for prostate seed implants. In general, maximization of the minimum peripheral dose (mPD) for given implanted total source strength tended to produce peripherally weighted seed patterns. Minimization of the urethral dose further reduced the loading in the central region of the PTV. Isodose conformity to the PTV was achieved when the set of objectives did not reflect seed positioning uncertainties; the corresponding optimal plan generally required fewer seeds and higher source strength per seed compared to the manual planning experience. When seed placement uncertainties were introduced into the set of treatment planning objectives, the optimal plan tended to reach a compromise between the preplanned outcome and the likelihood of retaining the preferred outcome after implantation. The reduction in the volatility of such seed configurations optimized under uncertainty was verified by sensitivity studies. Conclusion: An automated treatment planning engine incorporating real-time sensitivity analysis was found to be a useful tool in dosimetric planning for prostate

  8. hREV3 is essential for error-prone translesion synthesis past UV or benzo[a]pyrene diol epoxide-induced DNA lesions in human fibroblasts

    International Nuclear Information System (INIS)

    In S. cerevisiae, the REV3 gene, encoding the catalytic subunit of polymerase zeta, is involved in translesion synthesis and required for the production of mutations induced by ultraviolet radiation (UV) photoproducts and other DNA fork-blocking lesions, and for the majority of spontaneous mutations. To determine whether hREV3, the human homolog of yeast REV3, is similarly involved in error-prone translesion synthesis past UV photoproducts and other lesions that block DNA replication, an hREV3 antisense construct under the control of the TetP promoter was transfected into an infinite life span human fibroblast cell strain that expresses a high level of tTAk, the activator of that promoter. Three transfectant strains expressing high levels of hREV3 antisense RNA were identified and compared with their parental cell strain for sensitivity to the cytotoxic and mutagenic effects of UV. The three hREV3 antisense-expressing cell strains were not more sensitive than the parental strain to the cytotoxic effect of UV, but the frequency of mutants induced by UV in their HPRT gene was significantly reduced, i.e. to 14% that of the parent. Two of these hREV3 antisense-expressing cell strains were compared with the parental strain for sensitivity to (±)-7β,8α-dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE). They were not more sensitive than the parent strain to the cytotoxic effect of BPDE, but the frequency of mutants induced was significantly reduced, i.e. in one strain, to 17% that of the parent, and in the other, to 24%. DNA sequencing showed that the kinds of mutations induced by BPDE in the parental and the derivative strains did not differ and were similar to those found previously with finite life span human fibroblasts. The data strongly support the hypothesis that hRev3 plays a critical role in the induction of mutations by UV or BPDE. Because the level of hRev3 protein in human fibroblasts is below the level of antibody detection, it was not

  9. Epoxy resins used to seal brachytherapy seed

    International Nuclear Information System (INIS)

    Prostate cancer treatment with brachytherapy is recommended for patients with cancer at an early stage. In this treatment, small radioactive seeds are implanted directly in the prostate gland. These seeds are composed at least of one radionuclide carrier and an X-ray marker enclosed within a metallic tube usually sealed by laser process. This process is expensive and, furthermore, it can provoke a partial volatilization of the radionuclide and change the isotropy in dose distribution around the seed. In this paper, we present a new sealing process using epoxy resin. Three kinds of resins were utilized and characterized by scanning electron microscopy (SEM), energy dispersive X ray (EDS) and by differential scanning calorimetry (DSC) after immersion in simulated body fluid (SBF) and in sodium iodine solution (NaI). The sealing process showed excellent potential to replace the sealing laser usually employed. (author)

  10. Interstitial brachytherapy in carcinoma of the penis

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, A.J.; Ghosh, S.; Bhalavat, R.L. [Tata Memorial Hospital, Mumbai (India). Dept. of Radiation Oncology; Kulkarni, J.N. [Tata Memorial Hospital, Mumbai (India). Dept. of Surgery; Sequeira, B.V.E. [Tata Memorial Hospital, Mumbai (India). Dept. of Medical Physics

    1999-01-01

    Aim: Keeping in line with the increasing emphasis on organ preservation, we at the Tata Memorial Hospital have evaluated the role of Ir-192 interstitial implant as regards local control, functional and cosmetic outcome in early as well as locally recurrent carcinoma of the distal penis. Patients and Methods: From October 1988 to December 1996, 23 patients with histopathologically proven cancer of the penis were treated with radical radiation therapy using Ir-192 temporary interstitial implant. Our patients were in the age group of 20 to 60 years. The primary lesions were T1 and 7, T2 in 7 and recurrent in 9 patients. Only 7 patients had palpable groin nodes at presentation, all of which were pathologically negative. The median dose of implant was 50 Gy (range 40 to 60 Gy), using the LDR afterloading system and the Paris system of implant rules for dosimetry. Follow-up ranged from 4 to 117 months (median 24 months). Results: At last follow-up 18 of the 23 patients remained locally controlled with implant alone. Three patients failed only locally, 2 locoregionally and 1 only at the groin. Of the 5 patients who failed locally, 4 were successfully salvaged with partial penectomy and remained controlled when last seen. Local control with implant alone at 8 years was 70% by life table analysis. The patients had excellent functional and cosmetic outcome. We did not record any case of skin or softtissue necrosis. Only 2 patients developed meatal stenosis, both of which were treated endoscopically. Conclusion: Our results lead us to interpret that interstitial brachytherapy with Ir-192 offers excellent local control rates with preservation of organ and function. Penectomy can be reserved as a means for effective salvage. (orig.) [Deutsch] Ziel: Das Prinzip des Organerhalts gewinnt in der Onkologie zunehmend an Bedeutung. Ziel dieser Untersuchung war es, die Rolle der interstitiellen Brachytherapie mit Ir-192 zur Behandlung des fruehen und rezidivierten Peniskarzinoms zu

  11. Harmony search optimization for HDR prostate brachytherapy

    Science.gov (United States)

    Panchal, Aditya

    In high dose-rate (HDR) prostate brachytherapy, multiple catheters are inserted interstitially into the target volume. The process of treating the prostate involves calculating and determining the best dose distribution to the target and organs-at-risk by means of optimizing the time that the radioactive source dwells at specified positions within the catheters. It is the goal of this work to investigate the use of a new optimization algorithm, known as Harmony Search, in order to optimize dwell times for HDR prostate brachytherapy. The new algorithm was tested on 9 different patients and also compared with the genetic algorithm. Simulations were performed to determine the optimal value of the Harmony Search parameters. Finally, multithreading of the simulation was examined to determine potential benefits. First, a simulation environment was created using the Python programming language and the wxPython graphical interface toolkit, which was necessary to run repeated optimizations. DICOM RT data from Varian BrachyVision was parsed and used to obtain patient anatomy and HDR catheter information. Once the structures were indexed, the volume of each structure was determined and compared to the original volume calculated in BrachyVision for validation. Dose was calculated using the AAPM TG-43 point source model of the GammaMed 192Ir HDR source and was validated against Varian BrachyVision. A DVH-based objective function was created and used for the optimization simulation. Harmony Search and the genetic algorithm were implemented as optimization algorithms for the simulation and were compared against each other. The optimal values for Harmony Search parameters (Harmony Memory Size [HMS], Harmony Memory Considering Rate [HMCR], and Pitch Adjusting Rate [PAR]) were also determined. Lastly, the simulation was modified to use multiple threads of execution in order to achieve faster computational times. Experimental results show that the volume calculation that was

  12. MRI/TRUS data fusion for brachytherapy

    CERN Document Server

    Daanen, V; Giraud, J Y; Fourneret, P; Descotes, J L; Bolla, M; Collomb, D; Troccaz, Jocelyne

    2006-01-01

    BACKGROUND: Prostate brachytherapy consists in placing radioactive seeds for tumour destruction under transrectal ultrasound imaging (TRUS) control. It requires prostate delineation from the images for dose planning. Because ultrasound imaging is patient- and operator-dependent, we have proposed to fuse MRI data to TRUS data to make image processing more reliable. The technical accuracy of this approach has already been evaluated. METHODS: We present work in progress concerning the evaluation of the approach from the dosimetry viewpoint. The objective is to determine what impact this system may have on the treatment of the patient. Dose planning is performed from initial TRUS prostate contours and evaluated on contours modified by data fusion. RESULTS: For the eight patients included, we demonstrate that TRUS prostate volume is most often underestimated and that dose is overestimated in a correlated way. However, dose constraints are still verified for those eight patients. CONCLUSIONS: This confirms our init...

  13. Paddle-based rotating-shield brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yunlong; Xu, Weiyu [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 (United States); Flynn, Ryan T.; Kim, Yusung; Bhatia, Sudershan K.; Buatti, John M. [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Dadkhah, Hossein [Department of Biomedical Engineering, University of Iowa, 1402 Seamans Center, Iowa City, Iowa 52242 (United States); Wu, Xiaodong, E-mail: xiaodong-wu@uiowa.edu [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 and Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States)

    2015-10-15

    Purpose: The authors present a novel paddle-based rotating-shield brachytherapy (P-RSBT) method, whose radiation-attenuating shields are formed with a multileaf collimator (MLC), consisting of retractable paddles, to achieve intensity modulation in high-dose-rate brachytherapy. Methods: Five cervical cancer patients using an intrauterine tandem applicator were considered to assess the potential benefit of the P-RSBT method. The P-RSBT source used was a 50 kV electronic brachytherapy source (Xoft Axxent™). The paddles can be retracted independently to form multiple emission windows around the source for radiation delivery. The MLC was assumed to be rotatable. P-RSBT treatment plans were generated using the asymmetric dose–volume optimization with smoothness control method [Liu et al., Med. Phys. 41(11), 111709 (11pp.) (2014)] with a delivery time constraint, different paddle sizes, and different rotation strides. The number of treatment fractions (fx) was assumed to be five. As brachytherapy is delivered as a boost for cervical cancer, the dose distribution for each case includes the dose from external beam radiotherapy as well, which is 45 Gy in 25 fx. The high-risk clinical target volume (HR-CTV) doses were escalated until the minimum dose to the hottest 2 cm{sup 3} (D{sub 2cm{sup 3}}) of either the rectum, sigmoid colon, or bladder reached their tolerance doses of 75, 75, and 90 Gy{sub 3}, respectively, expressed as equivalent doses in 2 Gy fractions (EQD2 with α/β = 3 Gy). Results: P-RSBT outperformed the two other RSBT delivery techniques, single-shield RSBT (S-RSBT) and dynamic-shield RSBT (D-RSBT), with a properly selected paddle size. If the paddle size was angled at 60°, the average D{sub 90} increases for the delivery plans by P-RSBT on the five cases, compared to S-RSBT, were 2.2, 8.3, 12.6, 11.9, and 9.1 Gy{sub 10}, respectively, with delivery times of 10, 15, 20, 25, and 30 min/fx. The increases in HR-CTV D{sub 90}, compared to D-RSBT, were 16

  14. Balloon brachytherapy: how I do it

    International Nuclear Information System (INIS)

    To describe the technical aspects of insertion of MammoSite Radiation System, cosmetic issues, patients selection for the procedure and their satisfaction. Seventy patients underwent brachytherapy after insertion of the MammoSite catheter and received a boost HDR totaling 1500 cGy in six fractions over a three day period. Each patient then received 5 weeks of external beam radiotherapy to the whole breast. Only T1-2 patients were treated. All patients had excellent cosmetic results. The complications (minimal skin erythema, hematoma, balloon leak, seroma, were minimal. The safety and effectiveness of the MammoSite Radiation Therapy System as a replacement for whole breast irradiation in the treatment of breast cancer has not yet been established. (author)

  15. Verification of ophthalmic brachytherapy treatment planning

    International Nuclear Information System (INIS)

    Ophthalmic brachytherapy dose calculations were performed as an independent verification of commercial dosimetry software (BEBIG Plaque Simulator). Excel spreadsheets were constructed to follow the formalism of the AAPM Task Group No. 43. As a software commissioning tool, TG43 seed-based coordinates were reformatted to be compatible with plaque-based BEBIG dose tables for centrally positioned seeds. Plaque central axis doses were also calculated for rings of seeds. Close agreement with BEBIG doses was obtained in both cases. Tailored spreadsheet versions were subsequently created to verify patient treatment plans. Treatment time and dose to a specified central-axis point are calculated for ROPES plaques fully loaded with I-125 model 6702 seeds. Copyright (2001) Australasian College of Physical Scientists and Engineers in Medicine

  16. 10 CFR 35.490 - Training for use of manual brachytherapy sources.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Training for use of manual brachytherapy sources. 35.490 Section 35.490 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Manual Brachytherapy § 35.490 Training for use of manual brachytherapy sources. Except as provided in § 35.57, the...

  17. 10 CFR 35.2432 - Records of calibration measurements of brachytherapy sources.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of calibration measurements of brachytherapy... Records § 35.2432 Records of calibration measurements of brachytherapy sources. (a) A licensee shall maintain a record of the calibrations of brachytherapy sources required by § 35.432 for 3 years after...

  18. Evaluation of radiation dose on people adjacent to implant patients during brachytherapy for prostate cancer using {sup 192}Ir

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hoon; Ko, Seong Jin; Kang, Se Sik; Kim, Chang Soo [Catholic University, Busan (Korea, Republic of)

    2009-10-15

    The incidence of prostate cancer is rapidly increasing due to aging of the population and westernization of dietary habits, etc. As a result, the frequency of prostate cancer has become the fifth highest among all male cancers and the first among urological cancers. Brachytherapy is commonly used for locally progressing prostate cancers. Since the mid 1980s, therapies using radio-isotopes, such as low-invasive {sup 125}I, {sup 103}Pd and {sup 192}Ir, have been widely performed in the U.S. and Europe. However, brachytherapy involves implanting radio-isotopes into the human body which is of concern because it may expose the health care professionals administering the therapy to unnecessary radiation. Accordingly, this study intends to predict the radiation dose that people adjacent to patients implanted with a radio-isotope are exposed to during prostate cancer radiation therapy by using a mathematical anthropomorphic phantom and {sup 192}Ir.

  19. Evaluation of radiation dose on people adjacent to implant patients during brachytherapy for prostate cancer using 192Ir

    International Nuclear Information System (INIS)

    The incidence of prostate cancer is rapidly increasing due to aging of the population and westernization of dietary habits, etc. As a result, the frequency of prostate cancer has become the fifth highest among all male cancers and the first among urological cancers. Brachytherapy is commonly used for locally progressing prostate cancers. Since the mid 1980s, therapies using radio-isotopes, such as low-invasive 125I, 103Pd and 192Ir, have been widely performed in the U.S. and Europe. However, brachytherapy involves implanting radio-isotopes into the human body which is of concern because it may expose the health care professionals administering the therapy to unnecessary radiation. Accordingly, this study intends to predict the radiation dose that people adjacent to patients implanted with a radio-isotope are exposed to during prostate cancer radiation therapy by using a mathematical anthropomorphic phantom and 192Ir

  20. Ocular Brachytherapy Dosimetry for 103Pd and 125I in The Presence of Gold Nanoparticles: Monte Carlo Study

    CERN Document Server

    Asadi, S; Vahidian, M; Marghchouei, M; Masoudi, S Farhad

    2015-01-01

    The aim of the present Monte Carlo study is to evaluate the variation of energy deposition in healthy tissues in the human eye which is irradiated by brachytherapy sources in comparison with the resultant dose increase in the gold nanoparticle(GNP)-loaded choroidal melanoma. The effects of these nanoparticles on normal tissues are compared between 103Pd and 125I as two ophthalmic brachytherapy sources. Dose distribution in the tumor and healthy tissues have been taken into account for both mentioned brachytherapy sources. Also, in a certain point of the eye, the ratio of the absorbed dose by the normal tissue in the presence of GNPs to the absorbed dose by the same point in the absence of GNPs has been calculated. In addition, differences observed in the comparison of simple water phantom and actual simulated human eye in presence of GNPs are also a matter of interest that have been considered in the present work. The results show that the calculated dose enhancement factor in the tumor for 125I is higher tha...

  1. Methods for prostate stabilization during transperineal LDR brachytherapy

    International Nuclear Information System (INIS)

    In traditional prostate brachytherapy procedures for a low-dose-rate (LDR) radiation seed implant, stabilizing needles are first inserted to provide some rigidity and support to the prostate. Ideally this will provide better seed placement and an overall improved treatment. However, there is much speculation regarding the effectiveness of using regular brachytherapy needles as stabilizers. In this study, we explored the efficacy of two types of needle geometries (regular brachytherapy needle and hooked needle) and several clinically feasible configurations of the stabilization needles. To understand and assess the prostate movement during seed implantation, we collected in vivo data from patients during actual brachytherapy procedures. In vitro experimentation with tissue-equivalent phantoms allowed us to further understand the mechanics behind prostate stabilization. We observed superior stabilization with the hooked needles compared to the regular brachytherapy needles (more than 40% in bilateral parallel needle configuration). Prostate movement was also reduced significantly when regular brachytherapy needles were in an angulated configuration as compared to the parallel configuration (more than 60%). When the hooked needles were angulated for stabilization, further reduction in prostate displacement was observed. In general, for convenience of dosimetric planning and to avoid needle collision, all needles are desired to be in a parallel configuration. In this configuration, hooked needles provide improved stabilization of the prostate. On the other hand, both regular and hooked needles appear to be equally effective in reducing prostate movement when they are in angulated configurations, which will be useful in seed implantation using a robotic system. We have developed nonlinear spring-damper model for the prostate movement which can be used for adapting dosimetric planning during brachytherapy as well as for developing more realistic haptic devices and

  2. 电梯检验过程人因失误及其影响因素的实证研究%Empirical Study on Influencing Factors of Human Errors in the Process of Elevator Inspection

    Institute of Scientific and Technical Information of China (English)

    胡晓; 黄端; 石岿然; 蒋凤

    2014-01-01

    This paper examines the empirical test of key factors affecting human errors based on the samples of 248 senior and middle managers and primary technical staffs in foreign and state -owned elevator firms .The results show that personnel ability is negatively associated with human errors ;similarly ,organizational communication and organizational culture also have a directly and significantly negative impact on it .In addition ,there exists the related relationship among individual age ,work experiences ,marital status and human errors .This research provides sufficient basis to improve organizational management and avoid human errors for the elevator industry .%以248家电梯企业(包括外企和国企)的中高层管理人员和基层技术人员为调查对象,对人因失误的主要影响因素进行实证研究。研究结果表明,员工的能力素质、组织沟通与组织文化因素与人因失误的频繁程度显著负相关。此外,电梯检验过程人因失误与个体年龄、工龄、婚姻状况也存在相关性。研究结果为电梯行业改善组织管理,降低人因失误提供了充分的依据。

  3. Error Parsing: An alternative method of implementing social judgment theory

    OpenAIRE

    Crystal C. Hall; Oppenheimer, Daniel M.

    2015-01-01

    We present a novel method of judgment analysis called Error Parsing, based upon an alternative method of implementing Social Judgment Theory (SJT). SJT and Error Parsing both posit the same three components of error in human judgment: error due to noise, error due to cue weighting, and error due to inconsistency. In that sense, the broad theory and framework are the same. However, SJT and Error Parsing were developed to answer different questions, and thus use different m...

  4. Dosimetric analysis of BNCT - Boron Neutron Capture Therapy - coupled to 252Cf brachytherapy

    International Nuclear Information System (INIS)

    The incidence of brain tumors is increasing in world population; however, the treatments employed in this type of tumor have a high rate of failure and in some cases have been considered palliative, depending on histology and staging of tumor. Its necessary to achieve the control tumor dose without the spread irradiation cause damage in the brain, affecting patient neurological function. Stereotactic radiosurgery is a technique that achieves this; nevertheless, other techniques that can be used on the brain tumor control must be developed, in order to guarantee lower dose on health surroundings tissues other techniques must be developing. The 252Cf brachytherapy applied to brain tumors has already been suggested, showing promising results in comparison to photon source, since the active source is placed into the tumor, providing greater dose deposition, while more distant regions are spared. BNCT - Boron Neutron Capture Therapy - is another technique that is in developing to brain tumors control, showing theoretical superiority on the rules of conventional treatments, due to a selective irradiation of neoplasics cells, after the patient receives a borate compound infusion and be subjected to a epithermal neutrons beam. This work presents dosimetric studies of the coupling techniques: BNCT with 252Cf brachytherapy, conducted through computer simulation in MCNP5 code, using a precise and well discretized voxel model of human head, which was incorporated a representative Glioblastoma Multiform tumor. The dosimetric results from MCNP5 code were exported to SISCODES program, which generated isodose curves representing absorbed dose rate in the brain. Isodose curves, neutron fluency, and dose components from BNCT and 252Cf brachytherapy are presented in this paper. (author)

  5. Utilization and Outcomes of Breast Brachytherapy in Younger Women

    International Nuclear Information System (INIS)

    Purpose: To directly compare (1) radiation treatment utilization patterns; (2) risks of subsequent mastectomy; and (3) costs of radiation treatment in patients treated with brachytherapy versus whole-breast irradiation (WBI), in a national, contemporary cohort of women with incident breast cancer, aged 64 years and younger. Methods and Materials: Using MarketScan health care claims data, we identified 45,884 invasive breast cancer patients (aged 18-64 years), treated from 2003 to 2010 with lumpectomy, followed by brachytherapy (n=3134) or whole-breast irradiation (n=42,750). We stratified patients into risk groups according to age (Age<50 vs Age≥50) and endocrine therapy status (Endocrine− vs Endocrine+). “Endocrine+” patients filled an endocrine therapy prescription within 1 year after lumpectomy. Pathologic hormone receptor status was not available in this dataset. In brachytherapy versus WBI patients, utilization trends and 5-year subsequent mastectomy risks were compared. Stratified, adjusted subsequent mastectomy risks were calculated using proportional hazards regression. Results: Brachytherapy utilization increased from 2003 to 2010: in patients Age<50, from 0.6% to 4.9%; patients Age≥50 from 2.2% to 11.3%; Endocrine− patients, 1.3% to 9.4%; Endocrine+ patients, 1.9% to 9.7%. Age influenced treatment selection more than endocrine status: 17% of brachytherapy patients were Age<50 versus 32% of WBI patients (P<.001); whereas 41% of brachytherapy patients were Endocrine–versus 44% of WBI patients (P=.003). Highest absolute 5-year subsequent mastectomy risks occurred in Endocrine−/Age<50 patients (24.4% after brachytherapy vs 9.0% after WBI (hazard ratio [HR] 2.18, 95% confidence interval [CI] 1.37-3.47); intermediate risks in Endocrine−/Age≥50 patients (8.6% vs 4.9%; HR 1.76, 95% CI 1.26-2.46); and lowest risks in Endocrine+ patients of any age: Endocrine+/Age<50 (5.5% vs 4.5%; HR 1.18, 95% CI 0.61-2.31); Endocrine+/Age≥50 (4.2% vs 2

  6. Utilization and Outcomes of Breast Brachytherapy in Younger Women

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Grace L. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Huo, Jinhai [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Giordano, Sharon H. [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hunt, Kelly K. [Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Smith, Benjamin D., E-mail: bsmith3@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2015-09-01

    Purpose: To directly compare (1) radiation treatment utilization patterns; (2) risks of subsequent mastectomy; and (3) costs of radiation treatment in patients treated with brachytherapy versus whole-breast irradiation (WBI), in a national, contemporary cohort of women with incident breast cancer, aged 64 years and younger. Methods and Materials: Using MarketScan health care claims data, we identified 45,884 invasive breast cancer patients (aged 18-64 years), treated from 2003 to 2010 with lumpectomy, followed by brachytherapy (n=3134) or whole-breast irradiation (n=42,750). We stratified patients into risk groups according to age (Age<50 vs Age≥50) and endocrine therapy status (Endocrine− vs Endocrine+). “Endocrine+” patients filled an endocrine therapy prescription within 1 year after lumpectomy. Pathologic hormone receptor status was not available in this dataset. In brachytherapy versus WBI patients, utilization trends and 5-year subsequent mastectomy risks were compared. Stratified, adjusted subsequent mastectomy risks were calculated using proportional hazards regression. Results: Brachytherapy utilization increased from 2003 to 2010: in patients Age<50, from 0.6% to 4.9%; patients Age≥50 from 2.2% to 11.3%; Endocrine− patients, 1.3% to 9.4%; Endocrine+ patients, 1.9% to 9.7%. Age influenced treatment selection more than endocrine status: 17% of brachytherapy patients were Age<50 versus 32% of WBI patients (P<.001); whereas 41% of brachytherapy patients were Endocrine–versus 44% of WBI patients (P=.003). Highest absolute 5-year subsequent mastectomy risks occurred in Endocrine−/Age<50 patients (24.4% after brachytherapy vs 9.0% after WBI (hazard ratio [HR] 2.18, 95% confidence interval [CI] 1.37-3.47); intermediate risks in Endocrine−/Age≥50 patients (8.6% vs 4.9%; HR 1.76, 95% CI 1.26-2.46); and lowest risks in Endocrine+ patients of any age: Endocrine+/Age<50 (5.5% vs 4.5%; HR 1.18, 95% CI 0.61-2.31); Endocrine+/Age≥50 (4.2% vs 2

  7. The role of brachytherapy in radiation and isotopes centre of Khartoum (RICK)

    CERN Document Server

    Ali, A M

    2000-01-01

    As there are many efforts devoted in order to manage the cancer, here the researcher handle one of these efforts that play a major part in treating the cancer internationally, it is a brachytherapy system. Brachytherapy was carried out mostly with radium sources, but recently some artificial sources are incorporated in this mode of treatment such as Cs-137, Ir-192, Au-198, P-32, Sr-90 and I-125. The research cover history of brachytherapy and radioactive sources used in, techniques of implementation, radiation protection and methods of brachytherapy dose calculation, as well as brachytherapy in radiation and isotopes centre in Khartoum.

  8. A first experience of high dose rate (HDR) brachytherapy for tongue cancer

    International Nuclear Information System (INIS)

    We performed HDR brachytherapy for 12 patients with tongue cancer from April, 1996 to May, 1998. The patients included 7 men and 5 women. Ten of patients received HDR brachytherapy alone and two were treated with HDR brachytherapy and external irradiation and chemotherapy. In brachytherapy alone cases irradiated dose were between 42 Gy/14 fr and 60 Gy/10 fr, and the other two were irradiated 18 Gy/6 fr and 30 Gy/10 fr. We obtained CR for 12 patients and recurrence occurred in three cases. Late injury was observed in one case. In conclusion, HDR brachytherapy will be a promising therapeutic protocol for treatment of stage 1, 2 tongue cancer. (author)

  9. Construction balance analysis of dose rate medium brachytherapy TDS

    International Nuclear Information System (INIS)

    One of the most important part of brachytherapy instrument design activities is analyze by determining the centroid point of construction in order to maintain the balance of brachytherapy instrument, either during operation as well as when transported. Operation of brachytherapy is not only done in one place so it is necessary to balance the analysis of the forces at the time did not move, moved on the horizontal floor and sloping floor. Calculation approach who is done to calculate the weight of mechanical components on each module, and then calculate the centroid of each module, for the balance of forces analysis performed with the assumption at the time of brachytherapy in the position of not moving on a horizontal floor, moved from a place to another on the horizontal floor and on the floor with sloping angle 30°. Base on the results of this analysis are expected to balance the four wheels can move without slipping at the time of decline or incline. Also, results of analysis can be used in designing a mobile construction brachytherapy taking into consideration the aesthetic ideal, easy to operate, ensure the safety of equipment, operator and patient. (author)

  10. Percutaneous interstitial brachytherapy for adrenal metastasis. Technical report

    International Nuclear Information System (INIS)

    We developed and evaluated the feasibility of a brachytherapy technique as a safe and effective treatment for adrenal metastasis. Adapting a paravertebral insertion technique in radiofrequency ablation of adrenal tumors, we developed an interstitial brachytherapy for adrenal metastasis achievable on an outpatient basis. Under local anesthesia and under X-ray CT guidance, brachytherapy applicator needles were percutaneously inserted into the target. A treatment plan was created to eradicate the tumor while preserving normal organs including the spinal cord and kidney. We applied this interstitial brachytherapy technique to two patients: one who developed adrenal metastasis as the third recurrence of uterine cervical cancer after reirradiation, and one who developed metachronous multiple metastases from malignant melanoma. The whole procedure was completed in 2.5 hours. There were no procedure-related or radiation-related early/late complications. 18F-fluorodeoxyglucose positron emission tomography (FDG PET)-CT images at two and three months after treatment showed absence of FDG uptake, and no recurrence of the adrenal tumor was observed for over seven months until expiration, and for six months until the present, respectively. This interventional interstitial brachytherapy procedure may be useful as a safe and eradicative treatment for adrenal metastasis. (author)

  11. The effects of variations in the density and composition of eye materials on ophthalmic brachytherapy dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Asadi, Somayeh [Department of Physics, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Masoudi, Seyed Farhad, E-mail: masoudi@kntu.ac.ir [Department of Physics, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Shahriari, Majid [Department of Radiation Application, Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2012-04-01

    In ophthalmic brachytherapy dosimetry, it is common to consider the water phantom as human eye anatomy. However, for better clinical analysis, there is a need for the dose determination in different parts of the eye. In this work, a full human eye is simulated with MCNP-4C code by considering all parts of the eye, i.e., the lens, cornea, retina, choroid, sclera, anterior chamber, optic nerve, and bulk of the eye comprising vitreous body and tumor. The average dose in different parts of this full model of the human eye is determined and the results are compared with the dose calculated in water phantom. The central axes depth dose and the dose in whole of the tumor for these 2 simulated eye models are calculated as well, and the results are compared.

  12. The effects of variations in the density and composition of eye materials on ophthalmic brachytherapy dosimetry

    International Nuclear Information System (INIS)

    In ophthalmic brachytherapy dosimetry, it is common to consider the water phantom as human eye anatomy. However, for better clinical analysis, there is a need for the dose determination in different parts of the eye. In this work, a full human eye is simulated with MCNP-4C code by considering all parts of the eye, i.e., the lens, cornea, retina, choroid, sclera, anterior chamber, optic nerve, and bulk of the eye comprising vitreous body and tumor. The average dose in different parts of this full model of the human eye is determined and the results are compared with the dose calculated in water phantom. The central axes depth dose and the dose in whole of the tumor for these 2 simulated eye models are calculated as well, and the results are compared.

  13. SU-C-16A-01: In Vivo Source Position Verification in High Dose Rate (HDR) Prostate Brachytherapy Using a Flat Panel Imager: Initial Clinical Experience

    International Nuclear Information System (INIS)

    delivery, free of most potential human related errors identified in ICRP 97. This research is supported by funding from the Australian Government Department of Health through Cancer Australia grant no. 616614

  14. HDR neutron brachytherapy for prostatic cancer in lithuania

    International Nuclear Information System (INIS)

    The purpose of this report is to analyse the physical and radiobiological background of the HDR Cf-252 Neutron brachytherapy boost in the combined radiation therapy for locally advanced prostatic cancer. The treatment schedule:two fractions of the Cf-252 brachytherapy(5Gy-eq at the dose point 2 cm from source movement trajectory) with interval 24 hours; 5-8 fractions of the photon beam external radiation therapy(5 fractions per week, 2 Gy per fraction) to the prostate, two fractions of the Cf-252 brachytherapy and after that external beam radiation therapy is continued till total dose 40-45 Gy. Six patients completed the proposed combined radiation therapy. The results of this trial will be discussed

  15. Prostate brachytherapy in patients with prior evidence of prostatitis

    International Nuclear Information System (INIS)

    Purpose: To refute a misconception that a prior history of prostatitis is a contraindication to prostate brachytherapy. Methods and Materials: Five patients with clinical or pathologic evidence of prior prostatitis were treated with transperineal brachytherapy. Four of the patients received a single i.v. dose of ciprofloxacin (500 mg) intraoperatively. Postimplant antibiotics were not given. The pretreatment biopsy slides were reviewed. Results: Two of the five patients developed postimplant urinary retention requiring short-term catheterization, and both resolved spontaneously. One patient developed what appeared to be an exacerbation of his chronic prostatitis. Conclusion: We continue to recommend prostate brachytherapy for the treatment of clinically organ-confined cancer, with no concern about prior clinical or pathologic evidence of prostatitis

  16. Brachytherapy for elderly patients with stage II tongue cancer

    International Nuclear Information System (INIS)

    In treatment choices of stage II (T2N0M0) tongue cancer, brachytherapy is less invasive and superior in function preservation, therefore its role is more important in elderly patients. The aim of this study was to evaluate treatment results and morbidity of brachytherapy for elderly patients with stage II tongue cancer. Between 1980 and 2001, 198 patients with stage II tongue cancer were treated with brachytherapy at Hiroshima University Hospital. Patient ages ranged from 21 to 89 years old (median: 62 years old). Patients were divided into three groups as follows: 119 patients younger than 65 years old (Non-Elderly group), 53 patients between 65 and 75 years old (Junior Elderly group), and 26 patients 75 years or older (Senior Elderly group). Radiotherapy was performed in 101 patients with brachytherapy alone, and in 97 patients with brachytherapy and external radiotherapy. Chemotherapy was also performed in 77 patients. Follow-up period ranged from 4 to 243 months (median: 55 months). The 5-year local control rate was 85% in the Non-Elderly group, 85% in the Junior Elderly group and 81% in the Senior Elderly group. There was no significant difference among these groups. The 5-year cause-specific survival rate was 85%, 81% and 70% respectively. The Senior Elderly group showed poorer cause-specific survival rate than the other two groups (p=0.03). There was also a tendency of higher incidence of neck metastasis and low salvage rate by neck dissection in the Senior Elderly group. Although the Senior Elderly group showed poorer cause-specific survival rate, the local control rate was similar to those of the other two groups. Brachytherapy is an effective treatment option for elderly patients with stage II tongue cancer. (author)

  17. Practical research into the cognitive reliability and error analysis of the human factors in traffic accidents%CREAM追溯法在交通事故人因分析中的应用研究

    Institute of Scientific and Technical Information of China (English)

    付琴; 陈沅江; 邓奇春

    2011-01-01

    The present paper is aiming to analyze the root cause of human errors leading to disastrous human casualty and other kinds of traffic or transportation accidents by using the retrospective analysis method known as CREAM (cognitive reliability and error analysis method) . CREAM is also known as the representative second-generation human reliability analysis method to retrospect the deep-rooted cause of the traffic accidents and ways to predict their chance probability . The paper emphasizes the key influence of the context of the scenario on human behaviors and the drivers' performance because their driving behaviors are not isolated but influenced by the contextual situations they are involved in. In pursuing our research goal, we have analyzed the deep-rooted cause of human errors in the road traffic accidents with the retrospective analysis method in CREAM. First of all, a brief introduction to CREAM method, stressing the importance of intuitive understanding of the ineffective psychology and establishing human error identification model of road traffic accidents including four aspects, including slip, omission, violation and fault-commission. And, next, detailed recognized statistical data table of the accidents on the highway are given", which prove that human error is the key factor leading to the road traffic accidents. Moreover, the human errors are classified according to the relationship between the consequential and predictable factors, and then reorganized and complemented according to the actual facts. A data table of predictable causes can be shown. A simple consequential-antecedent retrospective table has been offered which is fit for the complex human error analysis and the process of the retrospective analysis has been prepared for practical application. We have also proposed items for further discussion of the quantitative and qualitative calculations so as to disclose the root causes leading to such disasters. In addition, we have also worked out

  18. Brachytherapy optimal planning with application to intravascular radiation therapy

    DEFF Research Database (Denmark)

    Sadegh, Payman; Mourtada, Firas A.; Taylor, Russell H.; Anderson, James H.

    1999-01-01

    We have been studying brachytherapy planning with the objective of manimizing the maximum deviation of the delivered dose from prescribed dose bounds for treatment volumes. A general framework for optimal treatment planning is presented and the minmax optimization is formulated as a linear program....... Dose rate calculations are based on the sosimetry formulation of the American Association of Physicists in Medicine, Task Group 43. We apply the technique to optimal planning for intravascular brachytherapy of intimal hyperplasia using ultrasound data and 192Ir seeds. The planning includes...

  19. Imaging method for monitoring delivery of high dose rate brachytherapy

    Science.gov (United States)

    Weisenberger, Andrew G; Majewski, Stanislaw

    2012-10-23

    A method for in-situ monitoring both the balloon/cavity and the radioactive source in brachytherapy treatment utilizing using at least one pair of miniature gamma cameras to acquire separate images of: 1) the radioactive source as it is moved in the tumor volume during brachytherapy; and 2) a relatively low intensity radiation source produced by either an injected radiopharmaceutical rendering cancerous tissue visible or from a radioactive solution filling a balloon surgically implanted into the cavity formed by the surgical resection of a tumor.

  20. Brachytherapy in vulvar cancer: analysis of 18 patients

    International Nuclear Information System (INIS)

    INTRODUCTION: Vulvar cancer is a rather common neoplasm in elderly patients. Surgery, followed eventually by postoperative radiotherapy, is the treatment of choice. The results of exclusive radiotherapy (external beam irradiation and/or brachytherapy) are not well defined and in the recent literature only small series are reported. Radiotherapy however is the only therapeutic option in patients who are not fit for radical surgery. It is thus necessary to review its indications and its modalities. PATIENTS METHODS AND RESULTS: From 1990 to 1994 18 pts with a diagnosis of squamous cell carcinoma of the vulva have been submitted to brachytherapy. Age ranged from 60 to 92 years (mean age 76, 1 ys). 14 pts were treated at diagnosis (11 pts) or for recurrent disease after surgery (3 pts). In 8 of them brachytherapy (total dose 35-45 Gy, dose rate: 0,4-0,78 Gy/h) was preceded by external beam irradiation (Co60 or electron beam, 40-50 Gy to primary and inguinal nodes); 6 pts were treated with brachytherapy alone (58-60 Gy; dose rate 0,44-0,63 Gy/h). 4 pts underwent to brachytherapy alone for local recurrence after surgery and postoperative radiotherapy (total dose 45-60 Gy; dose rate 0,37-0,49 Gy/h). Brachytherapy was always performed with 192 Ir. Plastic tubes (2 to 5 lines) were used for single plane implantation of small exophytic lesions limited to the labia (8 cases); a perineal template (10 cases) was employed in lesions extended to the vaginal mucosa or involving the clitoris or the area of the perineum. (10(14)) pts treated at diagnosis are alive and free from local recurrence after 11-48 mos. 3 of them, treated with brachytherapy alone, have presented a nodal recurrence in the groin after 14, 15 and 27 mos. respectively. All of them are alive and free from disease after surgery and external radiotherapy. None of the pts treated for recurrent disease after surgery + external beam radiotherapy has achieved a local control. CONCLUSION: Brachytherapy alone or

  1. Planning for brachytherapy using a 3D-simulation model

    International Nuclear Information System (INIS)

    A 3D-simulation model made with a milling system was applied to HDR-brachytherapy. The 3D-simulation model is used to simulate the 3D-structure of the lesion and the surrounding organs before the actual catheterization for brachytherapy. The first case was recurrent prostatic cancer in a 61-year-old man. The other case was lymph node recurrence of a 71-year-old woman's upper gum cancer. In both cases, the 3D-simulation model was very useful to simulate the 3D-conformation, to plan the treatment process and to avoid the risk accompanying treatment. (author)

  2. Validation of GPUMCD for low-energy brachytherapy seed dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Hissoiny, Sami; Ozell, Benoit; Despres, Philippe; Carrier, Jean-Francois [Ecole polytechnique de Montreal, Departement de genie informatique et genie logiciel, 2500 chemin de Polytechnique, Montreal, QC, H3T 1J4 (Canada); Departement de radio-oncologie, Centre hospitalier universitaire de Quebec (CHUQ), 11 Cote du Palais, Quebec, QC, G1R 2J6 (Canada); Departement de physique, Universite de Montreal, Montreal, QC (Canada) and Departement de radio-oncologie and Centre de recherche du CHUM, Centre hospitalier de l' Universite de Montreal (CHUM), Montreal, QC, H2L 4M1 (Canada)

    2011-07-15

    Purpose: To validate GPUMCD, a new package for fast Monte Carlo dose calculations based on the GPU (graphics processing unit), as a tool for low-energy single seed brachytherapy dosimetry for specific seed models. As the currently accepted method of dose calculation in low-energy brachytherapy computations relies on severe approximations, a Monte Carlo based approach would result in more accurate dose calculations, taking in to consideration the patient anatomy as well as interseed attenuation. The first step is to evaluate the capability of GPUMCD to reproduce low-energy, single source, brachytherapy calculations which could ultimately result in fast and accurate, Monte Carlo based, brachytherapy dose calculations for routine planning. Methods: A mixed geometry engine was integrated to GPUMCD capable of handling parametric as well as voxelized geometries. In order to evaluate GPUMCD for brachytherapy calculations, several dosimetry parameters were computed and compared to values found in the literature. These parameters, defined by the AAPM Task-Group No. 43, are the radial dose function, the 2D anisotropy function, and the dose rate constant. These three parameters were computed for two different brachytherapy sources: the Amersham OncoSeed 6711 and the Imagyn IsoStar IS-12501. Results: GPUMCD was shown to yield dosimetric parameters similar to those found in the literature. It reproduces radial dose functions to within 1.25% for both sources in the 0.5< r <10 cm range. The 2D anisotropy function was found to be within 3% at r = 5 cm and within 4% at r = 1 cm. The dose rate constants obtained were within the range of other values reported in the literature.Conclusion: GPUMCD was shown to be able to reproduce various TG-43 parameters for two different low-energy brachytherapy sources found in the literature. The next step is to test GPUMCD as a fast clinical Monte Carlo brachytherapy dose calculations with multiple seeds and patient geometry, potentially providing

  3. Radiation Protection Training in Intracoronary Brachytherapy

    International Nuclear Information System (INIS)

    To report the educational objectives and contents on Radiation Protection (RP) for the practice of Intracoronary Brachytherapy (ICB) procedures. The wide international experience on training programs for ICB as well as our own experience organizing several courses aimed at Cardiologists, Radio therapists and Medical Physicists has been used to elaborate specific RP objectives and contents. The objectives, differentiated for Cardiologists, Radio therapists, Medical Physicists, Nurses and Technicians, pretend to guarantee the safety and RP of both patient and staff in the procedures of ICB. The objectives are necessarily different because their RP formation and their role in the procedure are different. The general topics included in RP training programmes for ICB could be: general topics on RP (Interaction of radiation and matter, RP principles, radiobiology, etc), principles of operation of ICB and interventional X-ray equipment, quantification of radiation dose and risks, optimisation of protection of staff and patients, accidents and emergencies, regulations, responsibilities, quality assurance program, handling of ICB sources, installation and commissioning. Training programs based on the objectives presented in this paper would encourage positive safety culture in ICB and can also be used as a starting point by the Regulatory Authority for the authorization of new Installations and credentialing of professionals involved in this technique as well as for the continuous education of the staff involved. (Author) 10 refs

  4. Endovascular brachytherapy to prevent restenosis after angioplasty

    International Nuclear Information System (INIS)

    Endovascular radiotherapy is the first effective prophylaxis of restenosis after percutaneous transluminal angioplasty (PTA) and stenting. The FDA recently approved two devices for the delivery of intracoronary radiation following coronary artery stenting. Published multicenter, double-blind, randomized trials of intracoronary radiation therapy report good results for preventing in-stent restenosis, while the data for the peripheral circulation are still inconclusive. Beta-emitters are easier applicable and probably also safer, whereas gamma-emitters have been more extensively evaluated clinically so far. Primary indication for endovascular brachytherapy are patients at high risk for restenosis, such as previous restenoses, in-stent hyperplasia, long stented segment, long PTA lesion, narrow residual vascular lumen and diabetes. Data from coronary circulation suggest a safety margin of at least 4 to 10 mm at both ends of the angioplastic segment to avoid edge restenosis. To prevent late thrombosis of the treated coronary segment, antiplatelet therapy with clopidogrel and aspirin are recommended for at least 6 months after PTA and for 12 months after a newly implanted stent. An established medication regimen after radiotherapy of peripheral arteries is still lacking. (orig.)

  5. Halo's production in vitro on brachytherapy experiments

    International Nuclear Information System (INIS)

    Since earlier of 1960, one of the most significant contributions of radiation biology has been the theory of cell killing as a function of increasing doses of a cytotoxic agent, as well as the demonstration of repair of sublethal or potentially lethal damage after irradiation. The impact of cellular and molecular radiobiology, by exploitation of cellular mechanisms related to apoptosis, may be the cell killing with irradiation by including changes other than unrepaired DNA damage. Based on the understanding of the tumor microenvironment and how growth factors and proteins produced by irradiated cells may alter cellular processes, improved combined-modality strategies may emerge. This effect was show since 1960's, but here we propose to demonstrate this phenomenon in Brachytherapy. The present goal is to verify the macroscopic response through the production and analysis of clonogenic control based on halos generation by radioactive seeds of Ho-165 and Sm-153, aiming to study the effect of this type of irradiation. Confluent cell culture flasks with HeLa cell line were subjected to radiation in a period up to five half-lives of radionuclide, respectively. Devices were introduced which set the polymer-ceramic Ho-165 and Sm-153 seeds in the vials. After a period of exposure, the flasks were stained with violet Gensiana. The results showed the formation of halos control of confluent cancer cells. This paper will describe these experiments in the current stage of the research and report the implications of this new way of therapy for cancer treatment. (author)

  6. Learning from Errors

    OpenAIRE

    Martínez-Legaz, Juan Enrique; Soubeyran, Antoine

    2003-01-01

    We present a model of learning in which agents learn from errors. If an action turns out to be an error, the agent rejects not only that action but also neighboring actions. We find that, keeping memory of his errors, under mild assumptions an acceptable solution is asymptotically reached. Moreover, one can take advantage of big errors for a faster learning.

  7. Spectral CT evaluation of interstitial brachytherapy in pancreatic carcinoma xenografts: preliminary animal experience

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Shudong [Jiangsu University, Department of Radiology, The Affiliated Renmin Hospital, Zhenjiang, Jiangsu (China); Shanghai Jiao tong University, School of Medicine, Department of Radiology, Ruijin Hospital, Shanghai (China); Huang, Wei; Song, Qi; Lin, Xiaozhu; Wang, Zhongmin; Chen, Kemin [Shanghai Jiao tong University, School of Medicine, Department of Radiology, Ruijin Hospital, Shanghai (China); Chen, Yerong [Jiangsu University, Department of Radiology, The Affiliated Renmin Hospital, Zhenjiang, Jiangsu (China)

    2014-09-15

    We sought to evaluate the capability of spectral CT to detect the therapeutic response to {sup 125}I interstitial brachytherapy in a pancreatic carcinoma xenograft nude mouse model. Twenty mice bearing SWl990 human pancreatic cancer cell xenografts were randomly separated into two groups: experimental (n = 10; 1.0 mCi) and control (n = 10; 0 mCi). After a two-week treatment, spectral CT was performed. Contrast-to-noise ratio (CNR) and iodine concentration (IC) in the lesions were measured and normalized to the muscle tissue, and nIC CD31 immunohistochemistry was used to measure microvessel density (MVD). The relationships between the nIC and MVD of the tumours were analysed. The nIC of the experimental group was significantly lower than that of the control group during the multiphase examination. A significant difference in the MVD was observed between the two groups (P <0.001). The nIC values of the three-phase scans have a certain positive correlation with MVD (r = 0.57, p < 0.0001; r = 0.48, p = 0.002; r = 0.63, p = 0.0017 in the 10, 25, and 60 s phase, respectively). Spectral CT can be a useful non-invasive imaging modality in evaluating the therapeutic effect of {sup 125}I interstitial brachytherapy to a pancreatic carcinoma. (orig.)

  8. Ultrasound and PET-CT image fusion for prostate brachytherapy image guidance

    International Nuclear Information System (INIS)

    Fusion of medical images between different cross-sectional modalities is widely used, mostly where functional images are fused with anatomical data. Ultrasound has for some time now been the standard imaging technique used for treatment planning of prostate cancer cases. While this approach is laudable and has yielded some positive results, latest developments have been the integration of images from ultrasound and other modalities such as PET-CT to compliment missing properties of ultrasound images. This study has sought to enhance diagnosis and treatment of prostate cancers by developing MATLAB algorithms to fuse ultrasound and PET-CT images. The fused ultrasound-PET-CT image has shown to contain improved quality of information than the individual input images. The fused image has the property of reduced uncertainty, increased reliability, robust system performance, and compact representation of information. The objective of co-registering the ultrasound and PET-CT images was achieved by conducting performance evaluation of the ultrasound and PET-CT imaging systems, developing image contrast enhancement algorithm, developing MATLAB image fusion algorithm, and assessing accuracy of the fusion algorithm. Performance evaluation of the ultrasound brachytherapy system produced satisfactory results in accordance with set tolerances as recommended by AAPM TG 128. Using an ultrasound brachytherapy quality assurance phantom, average axial distance measurement of 10.11 ± 0.11 mm was estimated. Average lateral distance measurements of 10.08 ± 0.07 mm, 20.01 ± 0.06 mm, 29.89 ± 0.03 mm and 39.84 ± 0.37 mm were estimated for the inter-target distances corresponding to 10 mm, 20 mm, 30 mm and 40 mm respectively. Volume accuracy assessment produced measurements of 3.97 cm3, 8.86 cm3 and 20.11 cm3 for known standard volumes of 4 cm3, 9 cm3 and 20 cm3 respectively. Depth of penetration assessment of the ultrasound system produced an estimate of 5.37 ± 0.02 cm, indicating the

  9. Brachytherapy on restenosis. {sup 32}P radioisotope in animal model

    Energy Technology Data Exchange (ETDEWEB)

    Bergoc, R.; Rivera, E.; Cocca, C.; Martin, G.; Cricco, G. [Buenos Aires Univ. (Argentina). School of Pharmacy and Biochemistry; Croci, M.; Guzman, L.

    2000-05-01

    Despite a notorious decline in age-adjusted death rates for cardiovascular pathologies, coronary artery disease still remains as the main cause of mortality above the age of 40 in men and 60 in women. More than 25% of death in persons over the age of 35 are due to coronary disease. In about 50% of men and 30% of women, the first manifestation of the disease is an acute myocardial infarction and 10% a sudden cardiac death. In Argentina it is estimated that in 1998 about 100.000-115.000 people suffered as first manifestation of coronary illness a myocardial acute infarct. Angioplasty has an important and well established site in the treatment of the coronary illness and restenosis represents the principal complication of this method for myocardial re-vascularization. About a 35-40% of treated arteries present restenosis within the first six month the intervention with the concomitant need of re-interventions, re-hospitalizations, by-pass surgery, work discontinuity and the high cost for the health system. A number of drugs were tested as anti-restenosis: anticoagulants, aspirin, antispasmodics and lipid-lowering agents but none was clearly efficient; also, experimental studies in which intravascular irradiation with different source types and energies, radiation doses and doses rate to prevent restenosis was utilized; however, there is no consensus in many aspects of this intravascular brachytherapy. The first step in this work was to induce the experimental model in rabbits. Afterwards, by means of the balloon methodology and stent implantation, brachytherapy experiments were carried out to evaluate the biological effect on different layers of arteries, with different Doses using a beta particle emitting radioisotope ({sup 32}P). The arteriosclerotic lesions were induced in New Zealand rabbits through the administration of a diet with high cholesterol content. Angioplastic interventions on femoral arteries were done with balloon methodology and controlled by

  10. Brachytherapy on restenosis. 32P radioisotope in animal model

    International Nuclear Information System (INIS)

    Despite a notorious decline in age-adjusted death rates for cardiovascular pathologies, coronary artery disease still remains as the main cause of mortality above the age of 40 in men and 60 in women. More than 25% of death in persons over the age of 35 are due to coronary disease. In about 50% of men and 30% of women, the first manifestation of the disease is an acute myocardial infarction and 10% a sudden cardiac death. In Argentina it is estimated that in 1998 about 100.000-115.000 people suffered as first manifestation of coronary illness a myocardial acute infarct. Angioplasty has an important and well established site in the treatment of the coronary illness and restenosis represents the principal complication of this method for myocardial re-vascularization. About a 35-40% of treated arteries present restenosis within the first six month the intervention with the concomitant need of re-interventions, re-hospitalizations, by-pass surgery, work discontinuity and the high cost for the health system. A number of drugs were tested as anti-restenosis: anticoagulants, aspirin, antispasmodics and lipid-lowering agents but none was clearly efficient; also, experimental studies in which intravascular irradiation with different source types and energies, radiation doses and doses rate to prevent restenosis was utilized; however, there is no consensus in many aspects of this intravascular brachytherapy. The first step in this work was to induce the experimental model in rabbits. Afterwards, by means of the balloon methodology and stent implantation, brachytherapy experiments were carried out to evaluate the biological effect on different layers of arteries, with different Doses using a beta particle emitting radioisotope (32P). The arteriosclerotic lesions were induced in New Zealand rabbits through the administration of a diet with high cholesterol content. Angioplastic interventions on femoral arteries were done with balloon methodology and controlled by fluoroscopy

  11. Brachytherapy in Europe: philosophies, current practice and future directions

    International Nuclear Information System (INIS)

    Full text: Five months sabbatical leave provided an opportunity to visit six radiotherapy centres in France, Holland and England. While brachytherapy philosophies and practices within each country were similar, there were considerable differences in attitudes between countries. The Institute Gustave Roussy, home of the Paris System and host for the French sector confirmed that the Paris System is still very much the preferred dosimetry method in this part of the world. Though their preference for low dose rate brachytherapy is still evident, high dose rate brachytherapy has found some applications but the rules of the Paris System are never far away and the words 'what about the hyperdose sleeve' are firmly implanted into this visitor's brain. The use of real time dosimetry for I-125 prostate brachytherapy at the Institute Curie (Paris) provided an interesting contrast to the standard pre and post implant dosimetry techniques commonly employed elsewhere. The two Dutch centres on the itinerary, in stark contrast to the traditional techniques seen in France, have applied the power of computers to investigate optimisation of the classic dosimetry systems and called on the analysis techniques (DVH, NTCP, TCP etc) now familiar to us all in external beam therapy. The Cookridge Hospital in England fitted somewhere between the French and Dutch centres. This centre showed how both modern and traditional techniques could be applied in an efficient way for a large variety of treatment sites. Copyright (2000) Australasian College of Physical Scientists and Engineers in Medicine

  12. Curative brachytherapy for recurrent/residual tongue cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ayukawa, F.; Shibuya, H.; Yoshimura, Ryo-ichi; Watanabe, H.; Miura, M. [Tokyo Medical and Dental Univ. (Japan). Dept. of Radiology

    2007-03-15

    Purpose: The efficacy of curative low-dose-rate (LDR) brachytherapy for recurrent and/or residual cancer following radical operation or irradiation and posttreatment quality of life (QoL) were assessed. Patients and Methods: Between January 1979 and April 2004, 88 patients who had received curative LDR brachytherapy (28 with postoperative close or positive margins, six with postoperative recurrence, six with recurrence after external-beam irradiation, and 48 with recurrent/residual cancer after curative brachytherapy) were analyzed retrospectively. Late complications were assessed based on the RTOG/EORTC late radiation morbidity score scheme. Results: The 5-year relapse-free and cause-specific survival rates were 92% and 96%, respectively, in the close/positive margin group and 52% and 56%, respectively, in the postbrachytherapy recurrence or residual cancer group. The incidence of late side effects was 8% (2/26) in the close or positive margin group and 22% (4/18) in the postbrachytherapy group. The only grade 4 late complication (bone exposure) was observed in one patient in the postbrachytherapy group. Conclusion: LDR brachytherapy as reirradiation for recurrent/residual tongue cancer was effective, and there was no increase in complications. (orig.)

  13. Factors influencing outcome of I-125 prostate cancer brachytherapy

    NARCIS (Netherlands)

    Hinnen, K.A.

    2011-01-01

    Brachytherapy is becoming an increasingly popular prostate cancer treatment, probably due to the specific advantages of the procedure, such as the minimal invasiveness and the lower chance of impotence and incontinence. Nonetheless, because of the long follow-up that is required to obtain prostate c

  14. Dose determination in breast tumor in brachytherapy using Iridium-192

    International Nuclear Information System (INIS)

    Thermoluminescent dosimetry studies in vivo and in vitro aiming to determing radiation dose in the breast tumor, in brachytherapy using Iridium-192 was done. The correlation between radiation doses in tumor and external surface of the breast was investigated for correcting the time interval of radiation source implantation. (author)

  15. Verification of Oncentra brachytherapy planning using independent calculation

    Science.gov (United States)

    Safian, N. A. M.; Abdullah, N. H.; Abdullah, R.; Chiang, C. S.

    2016-03-01

    This study was done to investigate the verification technique of treatment plan quality assurance for brachytherapy. It is aimed to verify the point doses in 192Ir high dose rate (HDR) brachytherapy between Oncentra Masterplan brachytherapy treatment planning system and independent calculation software at a region of rectum, bladder and prescription points for both pair ovoids and full catheter set ups. The Oncentra TPS output text files were automatically loaded into the verification programme that has been developed based on spreadsheets. The output consists of source coordinates, desired calculation point coordinates and the dwell time of a patient plan. The source strength and reference dates were entered into the programme and then dose point calculations were independently performed. The programme shows its results in a comparison of its calculated point doses with the corresponding Oncentra TPS outcome. From the total of 40 clinical cases that consisted of two fractions for 20 patients, the results that were given in term of percentage difference, it shows an agreement between TPS and independent calculation are in the range of 2%. This programme only takes a few minutes to be used is preferably recommended to be implemented as the verification technique in clinical brachytherapy dosimetry.

  16. Brachytherapy in cervix cancers: techniques and concepts evolution

    International Nuclear Information System (INIS)