Extending the accredited low flow liquid calibration range

NARCIS (Netherlands)

Platenkamp, Tom; Lötters, Joost Conrad

2017-01-01

There is an increasing demand for ISO/IEC 17025:2005 accredited liquid flow calibrations in the range of 1 g/h to 30 kg/h. The accredited Low Flow liquid Calibration Setup [1] (LFCS) at Bronkhorst® covers a flow range of 1 to 200 g/h, leaving a traceability gap in the flow range of 0.2 to 30 kg/h.

The method validation step of biological dosimetry accreditation process

International Nuclear Information System (INIS)

Roy, L.; Voisin, P.A.; Guillou, A.C.; Busset, A.; Gregoire, E.; Buard, V.; Delbos, M.; Voisin, Ph.

2006-01-01

One of the missions of the Laboratory of Biological Dosimetry (L.D.B.) of the Institute for Radiation and Nuclear Safety (I.R.S.N.) is to assess the radiological dose after an accidental overexposure suspicion to ionising radiation, by using radio-induced changes of some biological parameters. The 'gold standard' is the yield of dicentrics observed in patients lymphocytes, and this yield is converted in dose using dose effect relationships. This method is complementary to clinical and physical dosimetry, for medical team in charge of the patients. To obtain a formal recognition of its operational activity, the laboratory decided three years ago, to require an accreditation, by following the recommendations of both 17025 General Requirements for the Competence of Testing and Calibration Laboratories and 19238 Performance criteria for service laboratories performing biological dosimetry by cyto-genetics. Diagnostics, risks analysis were realized to control the whole analysis process leading to documents writing. Purchases, personnel department, vocational training were also included in the quality system. Audits were very helpful to improve the quality system. One specificity of this technique is that it is not normalized therefore apart from quality management aspects, several technical points needed some validations. An inventory of potentially influent factors was carried out. To estimate their real effect on the yield of dicentrics, a Placket-Burman experimental design was conducted. The effect of seven parameters was tested: the BUdr (bromodeoxyuridine), PHA (phytohemagglutinin) and colcemid concentration, the culture duration, the incubator temperature, the blood volume and the medium volume. The chosen values were calculated according to the uncertainties on the way they were measured i.e. pipettes, thermometers, test tubes. None of the factors has a significant impact on the yield of dicentrics. Therefore the uncertainty linked to their use was considered as

The method validation step of biological dosimetry accreditation process

Energy Technology Data Exchange (ETDEWEB)

Roy, L.; Voisin, P.A.; Guillou, A.C.; Busset, A.; Gregoire, E.; Buard, V.; Delbos, M.; Voisin, Ph. [Institut de Radioprotection et de Surete Nucleaire, LDB, 92 - Fontenay aux Roses (France)

2006-07-01

One of the missions of the Laboratory of Biological Dosimetry (L.D.B.) of the Institute for Radiation and Nuclear Safety (I.R.S.N.) is to assess the radiological dose after an accidental overexposure suspicion to ionising radiation, by using radio-induced changes of some biological parameters. The 'gold standard' is the yield of dicentrics observed in patients lymphocytes, and this yield is converted in dose using dose effect relationships. This method is complementary to clinical and physical dosimetry, for medical team in charge of the patients. To obtain a formal recognition of its operational activity, the laboratory decided three years ago, to require an accreditation, by following the recommendations of both 17025 General Requirements for the Competence of Testing and Calibration Laboratories and 19238 Performance criteria for service laboratories performing biological dosimetry by cyto-genetics. Diagnostics, risks analysis were realized to control the whole analysis process leading to documents writing. Purchases, personnel department, vocational training were also included in the quality system. Audits were very helpful to improve the quality system. One specificity of this technique is that it is not normalized therefore apart from quality management aspects, several technical points needed some validations. An inventory of potentially influent factors was carried out. To estimate their real effect on the yield of dicentrics, a Placket-Burman experimental design was conducted. The effect of seven parameters was tested: the BUdr (bromodeoxyuridine), PHA (phytohemagglutinin) and colcemid concentration, the culture duration, the incubator temperature, the blood volume and the medium volume. The chosen values were calculated according to the uncertainties on the way they were measured i.e. pipettes, thermometers, test tubes. None of the factors has a significant impact on the yield of dicentrics. Therefore the uncertainty linked to their use was

Establishment of qualities mammography according to the standard IEC-61267 in the laboratory of metrology of ionizing radiation of the National Center of Dosimetry and enlargement of the accreditation by ENAC

International Nuclear Information System (INIS)

Roig Petit, F.; Mestre de Juan, V.; Alabau Albors, J.; Palma Copete, J.; Ruiz Rodriguez, J. C.; Pons Mocholi, S.

2013-01-01

The extension of the accreditation of the laboratory of the National Center Dosimetry (No. 58/LC10.036) by the national accreditation entity (ENAC), according to the ISO 17025 standard [2], for the standard qualities of mammography by the IEC 61267 comes to meet part of the needs that demand our health care environment in terms of radiation measuring instruments calibration. This work intends to publicize this enlargement commenting on the different phases of the process to get the accreditation. (Author)

[Fundamental aspects for accrediting medical equipment calibration laboratories in Colombia].

Science.gov (United States)

Llamosa-Rincón, Luis E; López-Isaza, Giovanni A; Villarreal-Castro, Milton F

2010-02-01

Analysing the fundamental methodological aspects which should be considered when drawing up calibration procedure for electro-medical equipment, thereby permitting international standard-based accreditation of electro-medical metrology laboratories in Colombia. NTC-ISO-IEC 17025:2005 and GTC-51-based procedures for calibrating electro-medical equipment were implemented and then used as patterns. The mathematical model for determining the estimated uncertainty value when calibrating electro-medical equipment for accreditation by the Electrical Variable Metrology Laboratory's Electro-medical Equipment Calibration Area accredited in compliance with Superintendence of Industry and Commerce Resolution 25771 May 26th 2009 consists of two equations depending on the case; they are: E = (Ai + sigmaAi) - (Ar + sigmaAr + deltaAr1) and E = (Ai + sigmaAi) - (Ar + sigmaA + deltaAr1). The mathematical modelling implemented for measuring uncertainty in the Universidad Tecnológica de Pereira's Electrical Variable Metrology Laboratory (Electro-medical Equipment Calibration Area) will become a good guide for calibration initiated in other laboratories in Colombia and Latin-America.

Laboratory Accreditation and the Calibration of Radiologic Measuring Tools

International Nuclear Information System (INIS)

Vancsura, P.; Kovago, J.

1998-01-01

In this paper is presented that accreditation in our days is a strict requirement for a lab for its results could be accepted on international level. Accreditation itself brings to new requirements, among them some are related to the calibration of the radiological measuring equipment

Calibration methods of plane-parallel ionization chambers used in electron dosimetry; Metodos de calibracao de camaras de ionizacao de placas paralelas para dosimetria de feixes de eletrons

Energy Technology Data Exchange (ETDEWEB)

Bulla, Roseli Tadeu

1999-07-01

The use of linear accelerators in radiotherapy is of great importance in Medicine, and according to international recommendations the electron beam dosimetry has to be performed using plane-parallel ionization chambers, previously calibrated in standard gamma radiation fields at accredited laboratories. In this work, calibration methods of plane-parallel ionization chambers used in dosimetry procedures of high energy electron beams of clinical accelerators were presented, tested and intercompared. The experiments were carried out using gamma radiation beams of {sup 60} Co at the Calibration Laboratory of Clinical Dosemeters at IPEN and electron beams od 4 to 16 MeV at the Radiotherapy Department of Hospital Israelita Albert Einstein, Sao Paulo. A method was chosen to be established at IPEN. Proposals of the calibration procedure, calibration certificate and data sheets are presented. (author)

US Department of Energy Laboratory Accreditation Program for personnel dosimetry systems (DOELAP)

International Nuclear Information System (INIS)

Carlson, R.D.; Gesell, T.F.; Kalbeitzer, F.L.; Roberson, P.L.; Jones, K.L.; MacDonald, J.C.; Vallario, E.J.; Pacific Northwest Lab., Richland, WA; USDOE Assistant Secretary for Nuclear Energy, Washington, DC

1988-01-01

The US Department of Energy (DOE) Office of Nuclear Safety has developed and initiated the DOE Laboratory Accreditation Program (DOELAP) for personnel dosimetry systems to assure and improve the quality of personnel dosimetry at DOE and DOE contractor facilities. It consists of a performance evaluation program that measures current performance and an applied research program that evaluates and recommends additional or improved test and performance criteria. It also provides guidance to DOE, identifying areas where technological improvements are needed. The two performance evaluation elements in the accreditation process are performance testing and onsite assessment by technical experts. Performance testing evaluates the participant's ability to accurately and reproducibly measure dose equivalent. Tests are conducted in accident level categories for low- and high-energy photons as well as protection level categories for low- and high-energy photons, beta particles, neutrons and mixtures of these

Technical guidelines for personnel dosimetry calibrations

International Nuclear Information System (INIS)

Roberson, P.L.; Fox, R.A.; Hadley, R.T.; Holbrook, K.L.; Hooker, C.D.; McDonald, J.C.

1983-01-01

A base of technical information has been acquire and used to evaluate the calibration, design, and performance of selected personnel systems in use at Department of Energy (DOE) facilites. A technical document was prepared to guide DOE and DOE contractors in selecting and evaluating personnel dosimetry systems and calibration. A parallel effort was initiated to intercompare the adiological calibrations standards used to calibrate DOE personnel dosimeters

Dosimetry control for radiation processing - basic requirements and standards

International Nuclear Information System (INIS)

Ivanova, M.; Tsrunchev, Ts.

2004-01-01

A brief review of the basic international codes and standards for dosimetry control for radiation processing (high doses dosimetry), setting up a dosimetry control for radiation processing and metrology control of the dosimetry system is made. The present state of dosimetry control for food processing and the Bulgarian long experience in food irradiation (three irradiation facilities are operational at these moment) are presented. The absence of neither national standard for high doses nor accredited laboratory for calibration and audit of radiation processing dosimetry systems is also discussed

Dosimetry in nuclear power plants

International Nuclear Information System (INIS)

Lastra B, J. A.

2008-12-01

To control the occupationally exposed personnel dose working at the Laguna Verde nuclear power plant, two types of dosemeters are used, the thermoluminescent (TLD) which is processed monthly, and the direct reading dosemeter that is electronic and works as daily control of personal dose. In the case of the electronic dosemeters of direct reading conventional, the readings and dose automatic registers and the user identity to which he was assigned to each dosemeter was to carry out the restricted area exit. In activities where the ionizing radiation sources are not fully characterized, it is necessary to relocate the personal dosemeter or assigned auxiliary dosemeters (TLDs and electronics) to determine the dose received by the user to both whole body and in any specific area of it. In jobs more complicated are used a tele dosimetry system where the radiation protection technician can be monitoring the user dose to remote control, the data transmission is by radio. The dosimetry activities are documented in procedures that include dosemeter inventories realization, the equipment and dosemeters calibration, the dosimetry quality control and the discrepancies investigation between the direct reading and TLD systems. TLD dosimetry to have technical expertise in direct and indirect dosimetry and two technicians in TLD dosimetry; electronic dosimetry to have 4 calibration technicians. For the electronic dosemeters are based on a calibrator source of Cesium-137. TLD dosemeters to have an automatic radiator, an automatic reader which can read up to 100 TLD dosemeters per hour and a semiautomatic reader. To keep the equipment under a quality process was development a process of initial entry into service and carried out a periodic verification of the heating cycles. It also has a maintenance contract for the equipment directly with the manufacturer to ensure their proper functioning. The vision in perspective of the dosimetry services of Laguna Verde nuclear power plant

Dosimetry intercomparisons in European medical device sterilization plants

DEFF Research Database (Denmark)

Miller, A.; Sharpe, P.H.G.

2000-01-01

Dosimetry intercomparisons have been carried out involving two-thirds of all European radiation sterilization facilities. Dosimeters for the intercomparisons were supplied by two accredited calibration laboratories. The results show good agreement, and indicate overall dosimetry accuracy of the o...... of the order of +/-5% (1 sigma) for both Co-60 and electron beam plants. (C) 2000 Elsevier Science Ltd. All rights reserved....

Accreditation of the Personal Dosimetry internal Service Tecnatom by the National Entity (ENAC); Acreditacion del Servicio de Dosimetria Personal Interna de Tecnatom por la Entidad Nacional de Acreditacion (ENAC)

Energy Technology Data Exchange (ETDEWEB)

Bravo, B.; Marchena, P.

2014-07-01

The service of personal Dosimetry internal Tecnatom has made the process of adapting its methodology and quality assurance, requirements technical and management will be required to obtain accreditation from the National Accreditation Entity according to ISO / IEC 170251 standard {sup G}eneral Requirements competence of testing and calibration laboratories. To carry out this process, the laboratory has defined quality criteria set out in their test procedures, based on ISO Standards 27048: 2011; ISO 20553: 2005 and ISO 28218: 2010. This paper describes what has been the methodology used to implement the requirements of different ISO test methods of SDPI Tecnatom. (Author)

Beta calibration and dosimetry at IPEN

International Nuclear Information System (INIS)

Caldas, L.V.E.

1983-01-01

A commercial extrapolation chamber (PTW, Germany) was tested in different beta radiation fields and its properties investigated. Its usefullness for beta radiation calibration and dosimetry was demonstrated. (Author) [pt

Individual dosimetry and calibration

International Nuclear Information System (INIS)

Hoefert, M.; Nielsen, M.

1996-01-01

In 1995 both the Individual Dosimetry and Calibration Sections worked under the condition of a status quo and concentrated fully on the routine part of their work. Nevertheless, the machine for printing the bar code which will be glued onto the film holder and hence identify the people when entering into high radiation areas was put into operation and most of the holders were equipped with the new identification. As far as the Calibration Section is concerned the project of the new source control system that is realized by the Technical Support Section was somewhat accelerated

Guide for selection and calibration of dosimetry systems for radiation processing

International Nuclear Information System (INIS)

2002-01-01

This guide covers the basis for selecting and calibrating dosimetry systems used to measure absorbed dose in gamma ray or X-ray fields and in electron beams used for radiation processing. It discusses the types of dosimetry systems that may be employed during calibration or on a routine basis as part of quality assurance in commercial radiation processing of products. This guide also discusses interpretation of absorbed dose and briefly outlines measurements of the uncertainties associated with the dosimetry. The details of the calibration of the analytical instrumentation are addressed in individual dosimetry system standard practices. The absorbed-dose range covered is up to 1 MGy (100 Mrad). Source energies covered are from 0.1 to 50 MeV photons and electrons. This guide should be used along with standard practices and guides for specific dosimetry systems and applications covered in other standards. Dosimetry for radiation processing with neutrons or heavy charged particles is not covered in this guide

NVLAP activities at Department of Defense calibration laboratories

Energy Technology Data Exchange (ETDEWEB)

Schaeffer, D.M. [Defense Nuclear Agency, Alexandria, VA (United States)

1993-12-31

There are 367 active radiological instrument calibration laboratories within the U.S. Department of Defense (DoD). Each of the four services in DoD manages, operates, and certifies the technical proficiency and competency of those laboratories under their cognizance. Each service has designated secondary calibration laboratories to trace all calibration source standards to the National Institute of Standards and Technology. Individual service radiological calibration programs and capabilities, present and future, are described, as well as the measurement quality assurance (MQA) processes for their traceability. National Voluntary Laboratory Accreditation Program (NVLAP) programs for dosimetry systems are briefly summarized. Planned NVLAP accreditation of secondary laboratories is discussed in the context of current technical challenges and future efforts.

NVLAP activities at Department of Defense calibration laboratories

International Nuclear Information System (INIS)

Schaeffer, D.M.

1993-01-01

There are 367 active radiological instrument calibration laboratories within the U.S. Department of Defense (DoD). Each of the four services in DoD manages, operates, and certifies the technical proficiency and competency of those laboratories under their cognizance. Each service has designated secondary calibration laboratories to trace all calibration source standards to the National Institute of Standards and Technology. Individual service radiological calibration programs and capabilities, present and future, are described, as well as the measurement quality assurance (MQA) processes for their traceability. National Voluntary Laboratory Accreditation Program (NVLAP) programs for dosimetry systems are briefly summarized. Planned NVLAP accreditation of secondary laboratories is discussed in the context of current technical challenges and future efforts

Variable transformation of calibration equations for radiation dosimetry

International Nuclear Information System (INIS)

Watanabe, Yoichi

2005-01-01

For radiation dosimetry, dosimetric equipment must be calibrated by using known doses. The calibration is done to determine an equation that relates the absorbed dose to a physically measurable quantity. Since the calibration equation is accompanied by unavoidable uncertainties, the doses estimated with such equations suffer from inherent uncertainties. We presented mathematical formulation of the calibration when the calibration relation is either linear or nonlinear. We also derived equations for the uncertainty of the estimated dose as a function of the uncertainties of the parameters in the equations and the measured physical quantity. We showed that a dosimeter with a linear calibration equation with zero dose-offset enables us to perform relative dosimetry without calibration data. Furthermore, a linear equation justifies useful data manipulations such as rescaling the dose and changing the dose-offset for comparing dose distributions. Considering that some dosimeters exhibit linear response with a large dose-offset or often nonlinear response, we proposed variable transformations of the measured physical quantity, namely, linear- and log-transformation methods. The proposed methods were tested with Kodak X-Omat V radiographic film and BANG (registered) polymer gel dosimeter. We demonstrated that the variable transformation methods could lead to linear equations with zero dose-offset and could reduce the uncertainty of the estimated dose

The DOE Laboratory Accreditation Program 8 years later

International Nuclear Information System (INIS)

Cummings, R.; Kershisnik, R.; Taylor, T.; Grothaus, G.; Loesch, R.M.

1994-01-01

The DOE Laboratory Accreditation Program was implemented in 1986. Currently, the program is conducting its seventeenth performance testing session for whole body personnel dosimeters. All but two DOE laboratories have gained accreditation for their whole body personnel dosimetry systems. Several test situations which were anticipated in the early stages of DOELAP have not materialized. In addition, the testing standard for whole body personnel dosimetry systems is under review and revision. In the near future, the accreditation programs for extremity dosimetry and bioassay will be implemented. This presentation summarizes the status and anticipated direction of the DOE whole body and extremity dosimetry and bioassay laboratory accreditation program

Calibration Laboratory for Medical Physics towards ISO/ IEC 17025 accreditation: Experience and challenges

International Nuclear Information System (INIS)

Asmaliza Hashim; Abdul Aziz Ramli; Muhammad Jamal Isa; Sharul Azlan Azizan

2011-01-01

Medical Physics Calibration Laboratory is laboratory where placed under Medical Physics Group, Radiation Healthy and Safety Division. This laboratory offers calibration services to their customers that covered doses calibration, tube voltan (kVp), exposure doses, sensitometer and densitometer. After 12 years of operation, it is the right time for this laboratory to upgrade their quality services based on ISO/ IEC 17025. Accreditation scope covered calibration for diagnostic doses only. Starting from 2009, serious effort was done to prepare the quality documents that covered quality manual, quality procedure and work orders. Meanwhile, several series of audit were done by Quality Management Center (QMC), now Innovation Management Center (IMC) with collaboration with Standard Department. This paper works revealed challenges and experience during the process toward ISO/ IEC 17025 accreditation. (author)

Establishing a standard calibration methodology for MOSFET detectors in computed tomography dosimetry

International Nuclear Information System (INIS)

Brady, S. L.; Kaufman, R. A.

2012-01-01

Purpose: The use of metal-oxide-semiconductor field-effect transistor (MOSFET) detectors for patient dosimetry has increased by ∼25% since 2005. Despite this increase, no standard calibration methodology has been identified nor calibration uncertainty quantified for the use of MOSFET dosimetry in CT. This work compares three MOSFET calibration methodologies proposed in the literature, and additionally investigates questions relating to optimal time for signal equilibration and exposure levels for maximum calibration precision. Methods: The calibration methodologies tested were (1) free in-air (FIA) with radiographic x-ray tube, (2) FIA with stationary CT x-ray tube, and (3) within scatter phantom with rotational CT x-ray tube. Each calibration was performed at absorbed dose levels of 10, 23, and 35 mGy. Times of 0 min or 5 min were investigated for signal equilibration before or after signal read out. Results: Calibration precision was measured to be better than 5%–7%, 3%–5%, and 2%–4% for the 10, 23, and 35 mGy respective dose levels, and independent of calibration methodology. No correlation was demonstrated for precision and signal equilibration time when allowing 5 min before or after signal read out. Differences in average calibration coefficients were demonstrated between the FIA with CT calibration methodology 26.7 ± 1.1 mV cGy −1 versus the CT scatter phantom 29.2 ± 1.0 mV cGy −1 and FIA with x-ray 29.9 ± 1.1 mV cGy −1 methodologies. A decrease in MOSFET sensitivity was seen at an average change in read out voltage of ∼3000 mV. Conclusions: The best measured calibration precision was obtained by exposing the MOSFET detectors to 23 mGy. No signal equilibration time is necessary to improve calibration precision. A significant difference between calibration outcomes was demonstrated for FIA with CT compared to the other two methodologies. If the FIA with a CT calibration methodology was used to create calibration coefficients for the

Establishing a standard calibration methodology for MOSFET detectors in computed tomography dosimetry.

Science.gov (United States)

Brady, S L; Kaufman, R A

2012-06-01

The use of metal-oxide-semiconductor field-effect transistor (MOSFET) detectors for patient dosimetry has increased by ~25% since 2005. Despite this increase, no standard calibration methodology has been identified nor calibration uncertainty quantified for the use of MOSFET dosimetry in CT. This work compares three MOSFET calibration methodologies proposed in the literature, and additionally investigates questions relating to optimal time for signal equilibration and exposure levels for maximum calibration precision. The calibration methodologies tested were (1) free in-air (FIA) with radiographic x-ray tube, (2) FIA with stationary CT x-ray tube, and (3) within scatter phantom with rotational CT x-ray tube. Each calibration was performed at absorbed dose levels of 10, 23, and 35 mGy. Times of 0 min or 5 min were investigated for signal equilibration before or after signal read out. Calibration precision was measured to be better than 5%-7%, 3%-5%, and 2%-4% for the 10, 23, and 35 mGy respective dose levels, and independent of calibration methodology. No correlation was demonstrated for precision and signal equilibration time when allowing 5 min before or after signal read out. Differences in average calibration coefficients were demonstrated between the FIA with CT calibration methodology 26.7 ± 1.1 mV cGy(-1) versus the CT scatter phantom 29.2 ± 1.0 mV cGy(-1) and FIA with x-ray 29.9 ± 1.1 mV cGy(-1) methodologies. A decrease in MOSFET sensitivity was seen at an average change in read out voltage of ~3000 mV. The best measured calibration precision was obtained by exposing the MOSFET detectors to 23 mGy. No signal equilibration time is necessary to improve calibration precision. A significant difference between calibration outcomes was demonstrated for FIA with CT compared to the other two methodologies. If the FIA with a CT calibration methodology was used to create calibration coefficients for the eventual use for phantom dosimetry, a measurement error ~12

Standardization of the calibration of brachytherapy sources at the IAEA dosimetry laboratory

International Nuclear Information System (INIS)

Shanta, A.; Andreo, P.

1996-01-01

A new service to SSDLs has been initiated at the IAEA Dosimetry Laboratory for providing calibrations of well-type ionisation chambers, used in brachytherapy applications, which are traceable to the International Measurement System. Considering that the most common radionuclide used in the developing countries is 137 Cs, two such sources of the type used for gynaecological intracavitary applications have been purchased by the Agency and calibrated at the National Institute of Standards and Technology (NIST), USA. These 137 Cs reference sources together with a well-type ionization chamber constitute the IAEA brachytherapy dosimetry standard. Based on the recommendations by a group of experts, a method has been developed for transferring calibrations to SSDLs which is described in this paper. The method is based on the acquisition by the SSDLs of sources and equipment similar to those at the IAEA. The well-type chamber is to be calibrated at the IAEA Dosimetry Laboratory, and this will be used at the SSDL to calibrate its own reference sources. These sources can in turn by used to calibrate well-type chambers from hospital users and to calibrate other type of sources by performing measurements in air. In order to standardize the procedures for the two methods and to provide guidance to the SSDLs, measurements have been carried out at the IAEA Dosimetry Laboratory. The reproducibility of the two type of measurements has been found to be better than 0.5%, and the uncertainty of calibrations estimated to be less than 1.5% (one standard deviation). (author). 8 refs, 8 figs, 2 tabs

Accreditation ISO/IEC 1705 in dosimetry: Experience and results; Acreditacion ISO/IEC 17025 en dosimetria: Experiencia y resultados

Energy Technology Data Exchange (ETDEWEB)

Martin Garcia, R.; Navarro Bravo, T.

2013-07-01

The objective of this work is to present the experience in the process of accreditation of the radiation dosimetry service in which there are trials for the determination of radiation doses due to internal and external exhibitions. Is They describe the aspects that were considered for the design and development of a system of quality and results after its implementation. A review of the benefits accreditation has been reported to the organization is finally made. (Author)

Quality assurance in radiotherapy dosimetry in China

International Nuclear Information System (INIS)

Li Kaibao; Luo Suming; Cheng Jinsheng; He Zhijian; An Jinggang; Hu Yimin; Feng Ningyuan

2002-01-01

In 1995, the SSDL in the Laboratory of Industrial Hygiene cooperated with Beijing Cancer Hospital, Chinese Academy of Medical science joined the IAEA Co-ordinated Research Programme (NO.8769/RO). According to the requirements of the project, an External Audit Group (EAG) in China was established in 1996 with the responsibilities of operating TLD-based quality audit for radiotherapy dosimetry. Since then. The national TLD dose quality audit services have been carried out in 7 provinces in China. Besides this, the national programmes for brachytherapy and stereostatic radiosurgery (SRS) treatment dosimetry were initiated in 2001. The activity measurement intercomparison between the SSDL and some hospitals for Ir-192 HDR brachytherapy sources has been performed using a HDR well-type ionization chamber (Model HDR 1000 plus) and CDX-2000A Charge Digitizer, which were calibrated in Accredited Dosimetry Calibration Laboratory, University of Wisconsin, USA. The preliminary results indicated that the agreement between SSDL measured activity and hospital stated activity was within ±5% for more than 80% of total participants

Secondary calibration laboratory for ionizing radiation laboratory accreitation program National Institute of Standards and Technology National Voluntary Laboratory Accreditation Program

Energy Technology Data Exchange (ETDEWEB)

Martin, P.R.

1993-12-31

This paper presents an overview of the procedures and requirements for accreditation under the Secondary Calibration Laboratory for Ionizing Radiation Program (SCLIR LAP). The requirements for a quality system, proficiency testing and the onsite assessment are discussed. The purpose of the accreditation program is to establish a network of secondary calibration laboratories that can provide calibrations traceable to the primary national standards.

Secondary calibration laboratory for ionizing radiation laboratory accreitation program National Institute of Standards and Technology National Voluntary Laboratory Accreditation Program

International Nuclear Information System (INIS)

Martin, P.R.

1993-01-01

This paper presents an overview of the procedures and requirements for accreditation under the Secondary Calibration Laboratory for Ionizing Radiation Program (SCLIR LAP). The requirements for a quality system, proficiency testing and the onsite assessment are discussed. The purpose of the accreditation program is to establish a network of secondary calibration laboratories that can provide calibrations traceable to the primary national standards

Establishment of qualities mammography according to the standard IEC-61267 in the laboratory of metrology of ionizing radiation of the National Center of Dosimetry and enlargement of the accreditation by ENAC; Establecimiento de las calidades de mamografia segun la norma IEC-61267 en el laboratorio de metrologia de radiaciones ionizantes del centro nacional de dosimetria (CND) y proceso de ampliacion de su acreditacion por ENAC

Energy Technology Data Exchange (ETDEWEB)

Roig Petit, F.; Mestre de Juan, V.; Alabau Albors, J.; Palma Copete, J.; Ruiz Rodriguez, J. C.; Pons Mocholi, S.

2013-07-01

The extension of the accreditation of the laboratory of the National Center Dosimetry (No. 58/LC10.036) by the national accreditation entity (ENAC), according to the ISO 17025 standard [2], for the standard qualities of mammography by the IEC 61267 comes to meet part of the needs that demand our health care environment in terms of radiation measuring instruments calibration. This work intends to publicize this enlargement commenting on the different phases of the process to get the accreditation. (Author)

Calibration curves for biological dosimetry

International Nuclear Information System (INIS)

Guerrero C, C.; Brena V, M. . E-mail cgc@nuclear.inin.mx

2004-01-01

The generated information by the investigations in different laboratories of the world, included the ININ, in which settles down that certain class of chromosomal leisure it increases in function of the dose and radiation type, has given by result the obtaining of calibrated curves that are applied in the well-known technique as biological dosimetry. In this work is presented a summary of the work made in the laboratory that includes the calibrated curves for gamma radiation of 60 Cobalt and X rays of 250 k Vp, examples of presumed exposure to ionizing radiation, resolved by means of aberration analysis and the corresponding dose estimate through the equations of the respective curves and finally a comparison among the dose calculations in those people affected by the accident of Ciudad Juarez, carried out by the group of Oak Ridge, USA and those obtained in this laboratory. (Author)

Guidelines for the Calibration of Routine Dosimetry Systems for use in Radiation Processing

DEFF Research Database (Denmark)

Sharpe, Peter; Miller, Arne

A set of guidelines has been developed to assist in the calibration of routine dosimetry systems for use in industrial radiation processing plants. Topics covered include the calibration of equipment, the performance of calibration irradiations and the derivation of mathematical functions...

Quality assurance manual for the Department of Energy laboratory accreditation program for personnel dosimetry systems

International Nuclear Information System (INIS)

1987-02-01

The overall purpose of this document is to establish a uniform approach to quality assurance. This will ensure that uniform, high-quality personnel dosimetry practices are followed by the participating testing laboratories. The document presents guidelines for calibrating and maintaining measurement and test equipment (M and TE), calibrating radiation fields, and subsequently irradiating and handling personnel dosimeters in laboratories involved in the DOE dosimetry systems testing program. Radiation energies for which the test procedures apply are photons with approximately 15 keV to 2 MeV, beta particles above 0.3 MeV, neutrons with approximately 1 keV to 2 MeV. 12 refs., 4 tabs

The U.S. Department of Energy Laboratory Accreditation Program for testing the performance of extremity dosimetry systems: a summary of the program status

International Nuclear Information System (INIS)

Cummings, F.M.; Carlson, R.D.; Gesell, T.F.; Loesch, R.M.

1992-01-01

In 1986, The U.S. Department of Energy (DOE) implemented a program to test the performance of its personnel whole-body dosimetry systems. This program was the DOE Laboratory Accreditation Program (DOELAP). The program parallels the performance testing program specified in the American National Standard for Dosimetry - Personnel Dosimetry Performance -Criteria for Testing (ANSI N13.11-1983), but also addresses the additional dosimetry needs of DOE facilities. As an extension of the whole-body performance testing program, the DOE is now developing a program to test the performance of personnel extremity dosimetry systems. The draft DOE standard for testing extremity dosimetry systems is much less complex than the whole-body dosimetry standard and reflects the limitations imposed on extremity dosimetry by dosimeter design and irradiation geometry. A pilot performance test session has been conducted to evaluate the proposed performance-testing standard. (author)

Experimental comparison among the laboratories accredited within the framework of the European Co-operation for Accreditation on the calibration of a radiation protection dosimeters in the terms of the quantity air Kerma

International Nuclear Information System (INIS)

Bovi, M.; Toni, M.P.; Tricomi, G.

2002-01-01

The European co-operation for Accreditation (EA) formalises the collaboration of the Accreditation Bodies of the Member States of the European Union and the European Free Trade Association covering all conformity assessment activities. This collaboration is based on a Memorandum of Understanding dated the 27 November 1997 and aims at developing and maintain Multilateral Agreements (MLAs) within EA and with non-members accreditation bodies. MLAs Signatories guarantee uniformity of accreditation by continuous and rigorous evaluation. Based on mutual confidence, the MLAs recognise the equivalence of the accreditation systems administered by EA Members and of certificates and reports issued by bodies accredited under these systems. A basic element of the program to establish and maintain mutual confidence among calibration services is the participation of the accredited laboratories in experimental interlaboratory comparisons (ILC) organised by EA members or other international organisations. The aim of these ILC is to verify the technical equivalence of calibration services within the EA. The ILC which it is dealt with in the present work was recently carried out over a period of two years, ending in May 2002. It interested the laboratories accredited in the ionising radiation field for calibration of dosimeters at radiation protection levels in terms of the quantity air kerma (K air ) due to 6 0C o and 1 37C s gamma radiation. The ILC was planned by the EA expert group on Ionising radiation and radioactivity and approved by the EA General Assembly in December 1999 with the title Calibration of a Radiation Protection Dosimeter under the code IR3. The need of this comparison also resulted from an inquiry carried out in 1998 by the expert group among the different Accreditation Bodies members of EA and associated to EA. The organization of the ILC was carried out according to the EA rules by the Italian Accreditation Body in the ionising radiation field, the SIT

Dosimetry through the Secondary Laboratory of Dosimetric Calibration of Mexico

International Nuclear Information System (INIS)

Tovar M, V.M.; Alvarez R, J.T.; Medina O, V.P.; Vergara M, F.; Anaya M, R.; Cejudo A, J.; Salinas L, B.

2004-01-01

In the beginnings of the sixty years an urgent necessity is presented mainly in the developing countries, of improving in important form the accuracy in the dosimetry of external faces in therapy of radiations (radiotherapy centers), mainly in the calibration of c linical dosemeters . In 1976 the International Atomic Energy Agency, (IAEA), and the World Health Organization, (WHO), they carried out a mutual agreement with regard to the establishment and operation of a net of Secondary Patron Laboratories of Dosimetry, (LSCD). The necessity to establish measure patterns in the field of the dosimetry of the ionizing radiations, is necessary, to have an accuracy but high in the dosimetry of the radiation beams in therapy which is highly dependent of the dose given to the tumor of those patient with cancer. Similar levels of accuracy are required in protection measures to the radiation with an acceptable smaller accuracy, however, when the personal dosemeters are used to determine the doses received by the individuals under work conditions, such mensurations in therapy of radiations and radiological protection will have traceability through a chain of comparisons to primary or national patterns. The traceability is necessary to assure the accuracy and acceptability of the dosimetric measures, as well as, the legal and economic implications. The traceability is also necessary in the dosimetry of high dose like in the sterilization of different products. The main function of the LSCD is to provide a service in metrology of ionizing radiations, maintaining the secondary or national patterns, which have a traceability to the International System of measures, which is based for if same in the comparison of patterns in the Primary Laboratories of Dosimetry (LPD) under the auspice of the International Office of Weights and Measure (BIPM). The secondary and national patterns in the LSCD constitute in Mexico, the national patterns of the magnitudes in the dosimetry of the

Radiotherapy Dosimetry Protocols For High Energy Photons And Electrons

International Nuclear Information System (INIS)

Thwaites, D.I.

1999-01-01

One vital requirement in radiotherapy is to ensure as closely as possible consistency in determination of dose between different centers and at different times, both within a given country and internationally, because the comparison and transfer of clinical experience and the evaluation of clinical trials is dependent on common statements of dose delivered. In addition at each loon] centre it is vital that the absorbed dose calibration of each beam is carried out to exacting and consistent standards, as this is the fundamental measurement upon which the quality of all treatments on that machine depend throughout its clinical lifetime. The systems in place to ensure consistency in dosimetry differ in the details from country to country, but all depend on the same basic considerations: - the use of ion chambers of similar design and similar construction materials, - traceable calibrations of these chambers to an accredited primary or secondary standard dosimetry laboratory (SSDL) in terms of some agreed relevant dosimetric quantity, - dose statements in terms of absorbed dose to a common material, water, - the application of an appropriate recommended national or international dosimetry protocol (or code of practice) which ensures commonality in the method of use of the calibrated ion chamber, the radiotherapy treatment beam calibration conditions and any data required to convert the ion chamber reading to absorbed dose to water, and - strict quality control on each step in this process

Fourth conference on radiation protection and dosimetry: Proceedings, program, and abstracts

Energy Technology Data Exchange (ETDEWEB)

Casson, W.H.; Thein, C.M.; Bogard, J.S. [eds.

1994-10-01

This Conference is the fourth in a series of conferences organized by staff members of Oak Ridge National Laboratory in an effort to improve communication in the field of radiation protection and dosimetry. Scientists, regulators, managers, professionals, technologists, and vendors from the United States and countries around the world have taken advantage of this opportunity to meet with their contemporaries and peers in order to exchange information and ideas. The program includes over 100 papers in 9 sessions, plus an additional session for works in progress. Papers are presented in external dosimetry, internal dosimetry, radiation protection programs and assessments, developments in instrumentation and materials, environmental and medical applications, and on topics related to standards, accreditation, and calibration. Individual papers are indexed separately on EDB.

(Re)implantation of quality system of LCR (Laboratory for Radiation Sciences) for accreditation in the standard ABNT NBR ISO/IEC 17025:2005

International Nuclear Information System (INIS)

Leite, Sandro P.; Fernandes, Elisabeth O.; David, Mariano G.; Pires, Evandro J.; Alves, Carlos F.E.; Almeida, Carlos E.

2014-01-01

This paper presents preparing procedure of the metrology laboratory (LABMETRO), which belongs Laboratorio de Ciencias Radiologicas of Rio de Janeiro , for postulating accreditation of its services metrology to INMETRO. This process, supported by the Technological Services Network SIBRATEC/FINEP for Radiation Protection and Dosimetry Technological Services, had as one of its aims to avoid possible technical barriers to the purchase services in the area of ionizing radiation laboratories. Accreditation will also enable the integration of services such laboratories in Brazilian Calibration Network (RBC). (author)

A round-robin gamma stereotactic radiosurgery dosimetry interinstitution comparison of calibration protocols

Energy Technology Data Exchange (ETDEWEB)

Drzymala, R. E., E-mail: drzymala@wustl.edu [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Alvarez, P. E. [Imaging and Radiation Oncology Core Houston, UT MD Anderson Cancer Center, Houston, Texas 77030 (United States); Bednarz, G. [Radiation Oncology Department, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15232 (United States); Bourland, J. D. [Department of Radiation Oncology, Wake Forest University, Winston-Salem, North Carolina 27157 (United States); DeWerd, L. A. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Ma, L. [Department of Radiation Oncology, University California San Francisco, San Francisco, California 94143 (United States); Meltsner, S. G. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Neyman, G. [Department of Radiation Oncology, The Cleveland Clinic Foundation, Cleveland, Ohio 44195 (United States); Novotny, J. [Medical Physics Department, Hospital Na Homolce, Prague 15030 (Czech Republic); Petti, P. L. [Gamma Knife Center, Washington Hospital Healthcare System, Fremont, California 94538 (United States); Rivard, M. J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Shiu, A. S. [Department of Radiation Oncology, University of Southern California, Los Angeles, California 90033 (United States); Goetsch, S. J. [San Diego Medical Physics, Inc., La Jolla, California 92037 (United States)

2015-11-15

Purpose: Absorbed dose calibration for gamma stereotactic radiosurgery is challenging due to the unique geometric conditions, dosimetry characteristics, and nonstandard field size of these devices. Members of the American Association of Physicists in Medicine (AAPM) Task Group 178 on Gamma Stereotactic Radiosurgery Dosimetry and Quality Assurance have participated in a round-robin exchange of calibrated measurement instrumentation and phantoms exploring two approved and two proposed calibration protocols or formalisms on ten gamma radiosurgery units. The objectives of this study were to benchmark and compare new formalisms to existing calibration methods, while maintaining traceability to U.S. primary dosimetry calibration laboratory standards. Methods: Nine institutions made measurements using ten gamma stereotactic radiosurgery units in three different 160 mm diameter spherical phantoms [acrylonitrile butadiene styrene (ABS) plastic, Solid Water, and liquid water] and in air using a positioning jig. Two calibrated miniature ionization chambers and one calibrated electrometer were circulated for all measurements. Reference dose-rates at the phantom center were determined using the well-established AAPM TG-21 or TG-51 dose calibration protocols and using two proposed dose calibration protocols/formalisms: an in-air protocol and a formalism proposed by the International Atomic Energy Agency (IAEA) working group for small and nonstandard radiation fields. Each institution’s results were normalized to the dose-rate determined at that institution using the TG-21 protocol in the ABS phantom. Results: Percentages of dose-rates within 1.5% of the reference dose-rate (TG-21 + ABS phantom) for the eight chamber-protocol-phantom combinations were the following: 88% for TG-21, 70% for TG-51, 93% for the new IAEA nonstandard-field formalism, and 65% for the new in-air protocol. Averages and standard deviations for dose-rates over all measurements relative to the TG-21 + ABS

Improvement of Accuracy in Environmental Dosimetry by TLD Cards Using Three-dimensional Calibration Method

Directory of Open Access Journals (Sweden)

HosseiniAliabadi S. J.

2015-06-01

Full Text Available Background: The angular dependency of response for TLD cards may cause deviation from its true value on the results of environmental dosimetry, since TLDs may be exposed to radiation at different angles of incidence from the surrounding area. Objective: A 3D setting of TLD cards has been calibrated isotropically in a standard radiation field to evaluate the improvement of the accuracy of measurement for environmental dosimetry. Method: Three personal TLD cards were rectangularly placed in a cylindrical holder, and calibrated using 1D and 3D calibration methods. Then, the dosimeter has been used simultaneously with a reference instrument in a real radiation field measuring the accumulated dose within a time interval. Result: The results show that the accuracy of measurement has been improved by 6.5% using 3D calibration factor in comparison with that of normal 1D calibration method. Conclusion: This system can be utilized in large scale environmental monitoring with a higher accuracy

Quality assurance in personal dosimetry of external radiation: present situation and future needs

International Nuclear Information System (INIS)

Ma, N.

2006-01-01

Whole body personal dosimetry is well established for the individual monitoring of radiation workers. High quality radiation dosimetry is essential for workers who rely upon personal dosemeters to record the amount of radiation to which they are exposed. The mandate has been given to the Personal Dosimetry, (secondary standard dosimetry laboratories) S.S.D.L., (Malaysian institute for nuclear energy research) M.I.N.T. to assure the individual monitoring for radiation workers in Malaysia. In 2005, the S.S.D.L;-M.I.N.T. supply, process and read out of personal dosemeters of nearly 13,000 dosimeters monthly, whereby. 12,000 are films and 1,000 are T.L.D.s. The objective of individual monitoring is not limited to the measurement of doses delivered to individuals, but it should demonstrate that limits of exposure have not been exceeded and that working conditions have not unexpectedly deteriorated. Dosimetry measurements are an important component of radiation protection programs and must be of high quality. The exposure of workers to radiation must be controlled and monitored in order to comply with regulatory requirements. S.S.D.L.-M.I.N.T; demonstrates that its performance is at an acceptable level by implementing overall system performance, as evidenced by the ISO 9001 certification of the Personal Dosimetry Service in 2002 and ISO/I.E.C. 17025 accreditation to the calibration laboratory in 2004. The certification and accreditation processes achieved the goal by formalizing the recognition of satisfactory performance, and providing evidence of this performance. Overall performances are assessed, personnel operating the system will be trained and are well qualified and all actions will be documented. The paper describes the overview of the Q.M.S. carried out at the S.S. D.L.-M.I.N.T.. During the implementation of Q.M.S. a few areas has been identified for future consideration. These include performance specification and type testing of dosemeters, which provide a

Accreditation of a system of extremity dosimetry: validation and uncertainty of method; Acreditacion de un sistema de dosimetria de extremidades: validacion e incertidumbre del metodo

Energy Technology Data Exchange (ETDEWEB)

Romero Gutierrez, A. M.; Rodriguez Jimenez, R.; Lopez Moyano, J. L.

2013-07-01

The authors' goal is to spread the practical experience gained during the accreditation process paying special attention to the process of method validation and estimation uncertainty of the dosimetry system. (Author)

Radiation protection - Performance criteria for service laboratories performing biological dosimetry by cytogenetics

International Nuclear Information System (INIS)

2004-01-01

This International Standard provides criteria for quality assurance and quality control, evaluation of the performance and the accreditation of biological dosimetry by cytogenetic service laboratories. This International Standard addresses: a) the confidentiality of personal information, for the customer and the service laboratory, b) the laboratory safety requirements, c) the calibration sources and calibration dose ranges useful for establishing the reference dose-effect curves allowing the dose estimation from chromosome aberration frequency, and the minimum detection levels, d) the scoring procedure for unstable chromosome aberrations used for biological dosimetry, e) the criteria for converting a measured aberration frequency into an estimate of absorbed dose, f) the reporting of results, g) the quality assurance and quality control, h) informative annexes containing examples of a questionnaire, instructions for customers, a data sheet for recording aberrations and a sample report

Onsite assessments for the Department of Energy Laboratory Accreditation Program

International Nuclear Information System (INIS)

McMahan, K.L.

1992-01-01

For Department of Energy (DOE) facilities, compliance with DOE Order 5480.11 became a requirement in January 1989. One of the requirements of this Order is that personal external dosimetry programs be accredited under the Department of Energy's Laboratory Accreditation Program (DOELAP) in Personnel Dosimetry. The accreditation process, from the facility's perspective, is two-fold: dosimeters must meet performance criteria in radiation categories appropriate for each facility, and personnel administering and carrying out the program must demonstrate good operating practices. The DOELAP onsite assessment is designed to provide an independent evaluation of the latter

Performance testing of dosimetry processors, status of NRC rulemaking for improved personnel dosimetry processing, and some beta dosimetry and instrumentation problems observed by NRC regional inspectors

International Nuclear Information System (INIS)

Dennis, N.A.; Kinneman, J.D.; Costello, F.M.; White, J.R.; Nimitz, R.L.

1983-01-01

Early dosimetry processor performance studies conducted between 1967 and 1979 by several different investigators indicated that a significant percentage of personnel dosimetry processors may not be performing with a reasonable degree of accuracy. Results of voluntary performance testing of US personnel dosimetry processors against the final Health Physics Society Standard, Criteria for Testing Personnel Dosimetry Performance by the University of Michigan for the Nuclear Regulatory Commission (NRC) will be summarized with emphasis on processor performance in radiation categories involving beta particles and beta particles and photon mixtures. The current status of the NRC's regulatory program for improved personnel dosimetry processing will be reviewed. The NRC is proposing amendments to its regulations, 10 CFR Part 20, that would require its licensees to utilize specified personnel dosimetry services from processors accredited by the National Voluntary Laboratory Accreditation Program of the National Bureau of Standards. Details of the development and schedule for implementation of the program will be highlighted. Finally, selected beta dosimetry and beta instrumentation problems observed by NRC Regional Staff during inspections of NRC licensed facilities will be discussed

Some methods for calibration and beta radiation dosimetry

International Nuclear Information System (INIS)

Caldas, Linda V. Ehlin

1980-01-01

The calibration of beta radiation was studied from the point of view of primary and secondary standardization, using extrapolation chambers and examining several effects. The properties of a commercial ionization chamber were investigated, and the possibility of its use in calibration and dosimetry of 90 Sr- 90 Y beta radiation was demonstrated . A secondary standard calibration facility was developed and the results obtained with this facility were compared with those obtained from a primary system directly or indirectly. Nearly energy independent response was obtained in.the range 60 keV to 0,8 MeV with this secondary standard. Two solid state techniques namely thermoluminescence (TL) and thermally stimulated exoelectron emission (TSEE) were also used for beta dosimetry. Various characteristics like reproducibility, response with dose,energy dependence, etc. were studied for the materials: LiF, CaF 2 ,Li 2 B 4 O 7 , Be O, CaSO 4 and Al 2 O 3 . TL detectors of thickness 0,9 mm underestimate the dose 60 μm thick CaSO 4 :Tm embedded on a thin aluminium plate gave energy independent response behind skin layers of 7 mg/cm 2 . Mixed field of beta, X and gamma radiation was analysed using this detector. Quartz based Be O and graphite based alpha beta-Al 2 O 3 were found to be good beta radiation detectors when the TSEE technique is used. Energy independent CaSO 4 :Tm TL dosimeters were used in international comparison for dose measurements and the results obtained were in agreement with the actual given doses within 10%. The TL detectors were also used for dose rate measurements from glazed painted tiles used in construction industry and a 85 Kr source used in textile and metal industries. Results obtained in the later case were Q compared with those using the secondary standard facility. (author)

Calibration of a MOSFET detection system for 6-MV in vivo dosimetry

International Nuclear Information System (INIS)

Scalchi, Paolo; Francescon, P.

1998-01-01

Purpose: Metal oxide semiconductor field-effect transistor (MOSFET) detectors were calibrated to perform in vivo dosimetry during 6-MV treatments, both in normal setup and total body irradiation (TBI) conditions. Methods and Materials: MOSFET water-equivalent depth, dependence of the calibration factors (CFs) on the field sizes, MOSFET orientation, bias supply, accumulated dose, incidence angle, temperature, and spoiler-skin distance in TBI setup were investigated. MOSFET reproducibility was verified. The correlation between the water-equivalent midplane depth and the ratio of the exit MOSFET readout divided by the entrance MOSFET readout was studied. MOSFET midplane dosimetry in TBI setup was compared with thermoluminescent dosimetry in an anthropomorphic phantom. By using ionization chamber measurements, the TBI midplane dosimetry was also verified in the presence of cork as a lung substitute. Results: The water-equivalent depth of the MOSFET is about 0.8 mm or 1.8 mm, depending on which sensor side faces the beam. The field size also affects this quantity; Monte Carlo simulations allow driving this behavior by changes in the contaminating electron mean energy. The CFs vary linearly as a function of the square field side, for fields ranging from 5 x 5 to 30 x 30 cm 2 . In TBI setup, varying the spoiler-skin distance between 5 mm and 10 cm affects the CFs within 5%. The MOSFET reproducibility is about 3% (2 SD) for the doses normally delivered to the patients. The effect of the accumulated dose on the sensor response is negligible. For beam incidence ranging from 0 deg. to 90 deg. , the MOSFET response varies within 7%. No monotonic correlation between the sensor response and the temperature is apparent. Good correlation between the water-equivalent midplane depth and the ratio of the exit MOSFET readout divided by the entrance MOSFET readout was found (the correlation coefficient is about 1). The MOSFET midplane dosimetry relevant to the anthropomorphic phantom

Establishing working standards of chromosome aberrations analysis for biological dosimetry

International Nuclear Information System (INIS)

Bui Thi Kim Luyen; Tran Que; Pham Ngoc Duy; Nguyen Thi Kim Anh; Ha Thi Ngoc Lien

2015-01-01

Biological dosimetry is an dose assessment method using specify bio markers of radiation. IAEA (International Atomic Energy Agency) and ISO (International Organization for Standardization) defined that dicentric chromosome is specify for radiation, it is a gold standard for biodosimetry. Along with the documents published by IAEA, WHO, ISO and OECD, our results of study on the chromosome aberrations induced by radiation were organized systematically in nine standards that dealing with chromosome aberration test and micronucleus test in human peripheral blood lymphocytes in vitro. This standard addresses: the reference dose-effect for dose estimation, the minimum detection levels, cell culture, slide preparation, scoring procedure for chromosome aberrations use for biodosimetry, the criteria for converting aberration frequency into absorbed dose, reporting of results. Following these standards, the automatic analysis devices were calibrated for improving biological dosimetry method. This standard will be used to acquire and maintain accreditation of the Biological Dosimetry laboratory in Nuclear Research Institute. (author)

Fast film dosimetry calibration method for IMRT treatment plan verification

International Nuclear Information System (INIS)

Schwob, N.; Wygoda, A.

2004-01-01

Intensity-Modulated Radiation Therapy (IMRT) treatments are delivered dynamically and as so, require routinely performed verification measurements [1]. Radiographic film dosimetry is a well-adapted method for integral measurements of dynamic treatments fields, with some drawbacks related to the known problems of dose calibration of films. Classically, several films are exposed to increasing doses, and a Net Optical Density (N.O.D) vs. dose sensitometric curve (S.C.) is generated. In order to speed up the process, some authors have developed a method based on the irradiation of a single film with a non-uniform pattern of O.D., delivered with a dynamic MLC. However, this curve still needs to be calibrated to dose by the means of measurements in a water phantom. It is recommended to make a new calibration for every series of measurements, in order to avoid the processing quality dependence of the film response. These frequent measurements are very time consuming. We developed a simple method for quick dose calibration of films, including a check of the accuracy of the calibration curve obtained

Status of radiation dosimetry in Germany using ionization chamber calibrated in terms of absorbed dose to water

International Nuclear Information System (INIS)

Hohlfeld, Klaus; Roos, Martin

1995-01-01

In 1984 the PTB as PSDL and the DIN Standard Committee on Radiology (NAR) in close co-operation decided that in Germany the measured absorbed dose to water in a water phantom should replace exposure in the dosimetry for radiation therapy. The PTB has established primary standards of water absorbed dose in the whole range of photon and electron radiation, and international comparisons at the BIPM and with other PSDLs proved agreement within 0.5%. Secondary standards are calibrated in a water phantom under reference conditions in a Co-60 gamma radiation beam at the PTB. Thus, the calibration factor in terms of water absorbed dose, N W , is transferred to the manufacturers of dosimeters, the German Calibration Service and the dosimetry laboratories of the verification authorities. The Verification Law subjects each ionization dosimeter used in the treatment of patients with external photon radiation beams under a type-test at PTB and under a verification procedure, where the calibration factor, N W , must be shown to be within given limits. The absorbed dose determination at the users' level follows the foralism prescribed in the Standard DIN 6800-2 (1995) 'Procedures for Absorbed Dose Determination in Radiology by the Ionization Method'. The concept of this DIN Standard uses exclusively one quantity from the primary standard to the user's instrument eliminating uncertainties and sources of mistakes associated with the conversion of a calibration factor. The concept is simple and clear and covers the whole range of photon and electron radiation. As a means of quality assurance in basic dosimetry the PTB runs a calibration service, up to now on a voluntary basis, which allows the user to compare his dosimetry system against PTB standards using mailed Fricke ampoules, with water absorbed dose as measured and used

Personal dosimetry service of TECNATOM: measurement system and methodology of calibration

International Nuclear Information System (INIS)

Marchena, Paloma; Bravo, Borja

2008-01-01

Full text: The implementation of a new integrated and practical working tool called ALEDIN within the Personal Dosimetry Service (PDS) of TECNATOM, have harmonized the methodology for the counting acquisition, detector calibration and data analysis using a friendly Windows (registered mark) environment. The knowledge of this methodology, due to the fact that is the final product of a R and D project, will help the users and the Regulatory Body for a better understanding of the internal activity measurement in individuals, allowing a more precise error identification and correction, and improving the whole process of the internal dosimetry. The development and implementation of a new calibration system of the whole body counters using NaI (Tl) detectors and the utilization of a new humanoid anthropometric phantom, BOMAB type, with a uniform radioactive source distributions, allow a better energy and activity calibration for different counting geometries covering a wide range of gamma spectra from low energies, less than 100 keV to about 2000 keV for the high energies spectra. This new calibration methodology implied the development of an improved system for the determination of the isotopic activity. This new system has been integrated in a Windows (registered mark) environment, applicable for counting acquisition and data analysis in the whole body counters WBC in cross connection with the INDAC software, which allow the interpretation of the measured activity as committed effective dose following all the new ICRP recommendations and dosimetric models for internal dose and bioassay measurements. (author)

DOE standard: The Department of Energy Laboratory Accreditation Program administration

International Nuclear Information System (INIS)

1998-12-01

This technical standard describes the US Department of Energy Laboratory Accreditation Program (DOELAP), organizational responsibilities, and the accreditation process. DOELAP evaluates and accredits personnel dosimetry and radiobioassay programs used for worker monitoring and protection at DOE and DOE contractor sites and facilities as required in Title 10, Code of Federal Regulations, Part 835, Occupational Radiation Protection. The purpose of this technical standard is to establish procedures for administering DOELAP and acquiring accreditation

Cause analysis for unsatisfactory results in proficiency testing activities: a case study of Brazilian calibration laboratories accredited under ISO/IEC 17025:2005⋆

Directory of Open Access Journals (Sweden)

Silva M.A.F.

2013-01-01

Full Text Available This work presents the results of a survey carried out among Brazilian calibration laboratories accredited under ISO/IEC 17025:2005 with the objective to identify how these laboratories investigate the root causes of unsatisfactory results in proficiency testing. The survey was coordinated by the Brazilian accreditation body, the General Coordination for Accreditation (Cgcre, of the Institute of Metrology, Quality and Technology (Inmetro.

Calibration of a tertiary standard in N-ISO qualities for radioprotection and personal dosimetry

International Nuclear Information System (INIS)

Rojas, Enrique; Seminario, Lizet

2013-01-01

Dosimetric calibration of radiation monitors and personal dosimeters in different radiological quantities are performed in order to obtain accurate measurements, for this reason the SSDL calculates the dosimetry calibration factor and its associated uncertainty, for each range of use. The calibration factor is performed using the known radiation field method and its uncertainty is calculated according to the ISO recommendations. The SSDL calculates the expanded uncertainty (U c ) with a coverage factor that provides a level of not less than 95 % of confidence. (authors).

DOE standard: The Department of Energy Laboratory Accreditation Program for radiobioassay

International Nuclear Information System (INIS)

1998-12-01

This technical standard describes the US Department of Energy Laboratory Accreditation Program (DOELAP) for Radiobioassay, for use by the US Department of Energy (DOE) and DOE Contractor radiobioassay programs. This standard is intended to be used in conjunction with the general administrative technical standard that describes the overall DOELAP accreditation process--DOE-STD-1111-98, Department of Energy Laboratory Accreditation Program Administration. This technical standard pertains to radiobioassay service laboratories that provide either direct or indirect (in vivo or in vitro) radiobioassay measurements in support of internal dosimetry programs at DOE facilities or for DOE and DOE contractors. Similar technical standards have been developed for other DOELAP dosimetry programs. This program consists of providing an accreditation to DOE radiobioassay programs based on successful completion of a performance-testing process and an on-site evaluation by technical experts. This standard describes the technical requirements and processes specific to the DOELAP Radiobioassay Accreditation Program as required by 10 CFR 835 and as specified generically in DOE-STD-1111-98

THE CHALLENGE OF CIEMAT INTERNAL DOSIMETRY SERVICE FOR ACCREDITATION ACCORDING TO ISO/IEC 17025 STANDARD, FOR IN VIVO AND IN VITRO MONITORING AND DOSE ASSESSMENT OF INTERNAL EXPOSURES.

Science.gov (United States)

Lopez, M A; Martin, R; Hernandez, C; Navarro, J F; Navarro, T; Perez, B; Sierra, I

2016-09-01

The accreditation of an Internal Dosimetry Service (IDS) according to ISO/IEC 17025 Standard is a challenge. The aim of this process is to guarantee the technical competence for the monitoring of radionuclides incorporated in the body and for the evaluation of the associated committed effective dose E(50). This publication describes the main accreditation issues addressed by CIEMAT IDS regarding all the procedures involving good practice in internal dosimetry, focussing in the difficulties to ensure the traceability in the whole process, the appropriate calculation of detection limit of measurement techniques, the validation of methods (monitoring and dose assessments), the description of all the uncertainty sources and the interpretation of monitoring data to evaluate the intake and the committed effective dose. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

DRDC Ottawa working standard for biological dosimetry

International Nuclear Information System (INIS)

Segura, T.M.; Prud'homme-Lalonde, L.; Thorleifson, E.; Lachapelle, S.; Mullins, D.; Qutob, S.; Wilkinson, D.

2005-07-01

This Standard provides quality assurance, quality control, and evaluation of the performance criteria for the purpose of accreditation of the Radiation Biology laboratory at Defence Research and Development Canada - Ottawa (DRDC Ottawa) using biological dosimetry to predict radiation exposure doses. The International Standard (ISO 19238) and the International Atomic Energy Association (IAEA) Technical Report Series No. 405 are used as guiding documents in preparation of this working document specific to the DRDC Ottawa Radiation Biology Laboratory. This Standard addresses: 1. The confidentiality of personal information, for the customer and the service laboratory; 2. The laboratory safety requirements; 3. The calibration sources and calibration dose ranges useful for establishing the reference dose-effect curves allowing the dose estimation from chromosome aberration frequency, and the minimum detection levels; 4. Transportation criteria for shipping of test samples to the laboratory; 5. Preparation of samples for analysis; 6. The scoring procedure for unstable chromosome aberrations used for biological dosimetry; 7. The criteria for converting a measured aberration frequency into an estimate of absorbed dose; 8. The reporting of results; 9. The quality assurance and quality control plan for the laboratory; and 10. Informative annexes containing examples of a questionnaire, instructions for customers, a data sheet for recording aberrations, a sample report and other supportive documents. (author)

DRDC Ottawa working standard for biological dosimetry

Energy Technology Data Exchange (ETDEWEB)

Segura, T M; Prud' homme-Lalonde, L [Defence Research and Development Canada, Ottawa, Ontario (Canada); Thorleifson, E [Health Canada, Gatineau, Quebec (Canada); Lachapelle, S; Mullins, D [JERA Consulting (Canada); Qutob, S [Health Canada, Gatineau, Quebec (Canada); Wilkinson, D

2005-07-15

This Standard provides quality assurance, quality control, and evaluation of the performance criteria for the purpose of accreditation of the Radiation Biology laboratory at Defence Research and Development Canada - Ottawa (DRDC Ottawa) using biological dosimetry to predict radiation exposure doses. The International Standard (ISO 19238) and the International Atomic Energy Association (IAEA) Technical Report Series No. 405 are used as guiding documents in preparation of this working document specific to the DRDC Ottawa Radiation Biology Laboratory. This Standard addresses: 1. The confidentiality of personal information, for the customer and the service laboratory; 2. The laboratory safety requirements; 3. The calibration sources and calibration dose ranges useful for establishing the reference dose-effect curves allowing the dose estimation from chromosome aberration frequency, and the minimum detection levels; 4. Transportation criteria for shipping of test samples to the laboratory; 5. Preparation of samples for analysis; 6. The scoring procedure for unstable chromosome aberrations used for biological dosimetry; 7. The criteria for converting a measured aberration frequency into an estimate of absorbed dose; 8. The reporting of results; 9. The quality assurance and quality control plan for the laboratory; and 10. Informative annexes containing examples of a questionnaire, instructions for customers, a data sheet for recording aberrations, a sample report and other supportive documents. (author)

Calibration of a He accumulation fluence monitor for fast reactor dosimetry

Energy Technology Data Exchange (ETDEWEB)

Ito, Chikara [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

1997-03-01

The helium accumulation fluence monitor (HAFM) has been developed for a fast reactor dosimetry. The HAFM measurement system was calibrated using He gas and He implanted samples and the measurement accuracy was confirmed to be less than 5%. Based on the preliminary irradiation test in JOYO, the measured He in the {sup 10}B type HAFM agreed well with the calculated values using the JENDL-3.2 library. (author)

Proceedings of the second conference on radiation protection and dosimetry

International Nuclear Information System (INIS)

Swaja, R.E.; Sims, C.S.

1988-11-01

The Second Conference on Radiation Protection and Dosimetry was held during October 31--November 3, 1988, at the Holiday Inn, Crowne Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To facilitate meeting these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical sessions included external dosimetry, internal dosimetry, calibration, standards and regulations, instrumentation, accreditation and test programs, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. This document provides a summary of the conference technical program and a partial collection of full papers for the oral presentations in order of delivery. Individual papers were processed separately for the data base

Proceedings of the second conference on radiation protection and dosimetry

Energy Technology Data Exchange (ETDEWEB)

Swaja, R. E.; Sims, C. S. [eds.

1988-11-01

The Second Conference on Radiation Protection and Dosimetry was held during October 31--November 3, 1988, at the Holiday Inn, Crowne Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To facilitate meeting these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical sessions included external dosimetry, internal dosimetry, calibration, standards and regulations, instrumentation, accreditation and test programs, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. This document provides a summary of the conference technical program and a partial collection of full papers for the oral presentations in order of delivery. Individual papers were processed separately for the data base.

Neutron personnel dosimetry

International Nuclear Information System (INIS)

Griffith, R.V.

1981-01-01

The current state-of-the-art in neutron personnel dosimetry is reviewed. Topics covered include dosimetry needs and alternatives, current dosimetry approaches, personnel monitoring devices, calibration strategies, and future developments

Measurement protocols for performance testing of dosimetry services for external radiations

International Nuclear Information System (INIS)

1993-01-01

In the Health and Safety Executive's ''Requirements for the Approval of Dosimetry Services under the Ionising Radiations Regulations 1985'', it is stipulated that dosimetry services seeking approval must show that they have successfully completed a performance test. The services must arrange for the tests to be carried out on application and thereafter every 18 months, by a laboratory which has received accreditation from the National Measurement Accreditation Service (NAMAS) for the whole performance testing activity. The performance tests must be carried out to published protocols and the purpose here is to provide protocols for external, whole body film and TLD dosimetry services, and for skin and extremity dosimetry services. (Author)

The challenge of Ciemat internal dosimetry service for accreditation according to ISO/IEC 17025 standard, for in vivo and in vitro monitoring and dose assessment of internal exposures

International Nuclear Information System (INIS)

Lopez, M.A.; Martin, R.; Hernandez, C.; Navarro, J.F.; Navarro, T.; Perez, B.; Sierra, I.

2016-01-01

The accreditation of an Internal Dosimetry Service (IDS) according to ISO/IEC 17025 Standard is a challenge. The aim of this process is to guarantee the technical competence for the monitoring of radionuclides incorporated in the body and for the evaluation of the associated committed effective dose E(50). This publication describes the main accreditation issues addressed by CIEMAT IDS regarding all the procedures involving good practice in internal dosimetry, focussing in the difficulties to ensure the traceability in the whole process, the appropriate calculation of detection limit of measurement techniques, the validation of methods (monitoring and dose assessments), the description of all the uncertainty sources and the interpretation of monitoring data to evaluate the intake and the committed effective dose. CIEMAT Internal Dosimetry Service (IDS) has developed and implemented a quality system based on ISO/IEC 17025 to ensure compliance with the general requirements of this reference standard. The development of documentary support according to this quality system permitted to standardise the systematic activities performed within the whole body counter and in vitro bioassay laboratories as well as the procedures carried out by qualified staff in charge of internal dose assessment. There was no previous experience in the accreditation of other internal dosimetry services in Spain. Then, requirements from the national regulatory body (Nuclear Safety Council, CSN) and national accreditation entity (ENAC) have been considered. The main concerns were to guarantee the traceability in the whole process and to avoid possible charge of interpretation or subjectivity in the methodology of dose assessment due to intakes of radionuclides when calculating from monitoring data. All the related international standards dealing with internal dosimetry were taken into account: ISO 28218 'Performance criteria for radiobioassay', ISO 27048 'Dose Assessment for the

The calibration procedures in the Studsvik standardized personnel dosimetry system

International Nuclear Information System (INIS)

Widell, C.O.

1978-01-01

Every large nuclear installation in Sweden reads its own personnel TLDs. In order to supervise this decentralized reading of dose meters, the TLD readers are connected by telephone lines to a central computer for dose registration. This computer is used both for registering the personnel doses and for checking the TLD readers. This checking is performed by the use of pre-irradiated calibration dose meters which are always used when a batch of personnel dose meters are read. The pre-irradiated dose meters are either irradiated using 137 Cs to various doses up to 100mSv(10000mrem) or using a 90 Sr source in a reference dose irradiator to a dose equal to 3mSv(300mrem) from a 137 Cs source. The results from the reading of the pre-irradiated dose meters are processed by the computer and a calibration factor is calculated. The calibration factor is automatically used to calculate the doses to the personnel TLD's. However, if the calibration factor deviates by more than 10% from the previously used factor, this fact is shown to the operator - who then has to decide what calibration factor is going to be used. This calibration and supervisory procedure together with the safety interlocks in the TLD readers has resulted in a very reliable and accurate dosimetry system. (author)

On the calibration process of film dosimetry: OLS inverse regression versus WLS inverse prediction

International Nuclear Information System (INIS)

Crop, F; Thierens, H; Rompaye, B Van; Paelinck, L; Vakaet, L; Wagter, C De

2008-01-01

The purpose of this study was both putting forward a statistically correct model for film calibration and the optimization of this process. A reliable calibration is needed in order to perform accurate reference dosimetry with radiographic (Gafchromic) film. Sometimes, an ordinary least squares simple linear (in the parameters) regression is applied to the dose-optical-density (OD) curve with the dose as a function of OD (inverse regression) or sometimes OD as a function of dose (inverse prediction). The application of a simple linear regression fit is an invalid method because heteroscedasticity of the data is not taken into account. This could lead to erroneous results originating from the calibration process itself and thus to a lower accuracy. In this work, we compare the ordinary least squares (OLS) inverse regression method with the correct weighted least squares (WLS) inverse prediction method to create calibration curves. We found that the OLS inverse regression method could lead to a prediction bias of up to 7.3 cGy at 300 cGy and total prediction errors of 3% or more for Gafchromic EBT film. Application of the WLS inverse prediction method resulted in a maximum prediction bias of 1.4 cGy and total prediction errors below 2% in a 0-400 cGy range. We developed a Monte-Carlo-based process to optimize calibrations, depending on the needs of the experiment. This type of thorough analysis can lead to a higher accuracy for film dosimetry

(Re)implantation of quality system of LCR (Laboratory for Radiation Sciences) for accreditation in the standard ABNT NBR ISO/IEC 17025:2005; (Re)implantacao do sistema da qualidade do LCR para acreditacao na ABNT NBR ISO/IEC 17025:2005

Energy Technology Data Exchange (ETDEWEB)

Leite, Sandro P., E-mail: leite_sp@ig.com.br [Rede Sibratec, Sao Paulo, SP (Brazil); Fernandes, Elisabeth O.; David, Mariano G.; Pires, Evandro J.; Alves, Carlos F.E.; Almeida, Carlos E. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil)

2014-07-01

This paper presents preparing procedure of the metrology laboratory (LABMETRO), which belongs Laboratorio de Ciencias Radiologicas of Rio de Janeiro , for postulating accreditation of its services metrology to INMETRO. This process, supported by the Technological Services Network SIBRATEC/FINEP for Radiation Protection and Dosimetry Technological Services, had as one of its aims to avoid possible technical barriers to the purchase services in the area of ionizing radiation laboratories. Accreditation will also enable the integration of services such laboratories in Brazilian Calibration Network (RBC). (author)

Calibration of photon and beta ray sources used in brachytherapy. Guidelines on standardized procedures at Secondary Standards Dosimetry Laboratories

International Nuclear Information System (INIS)

2004-03-01

It has generally been recognized that international harmonization in radiotherapy dosimetry is essential. Consequently, the IAEA has given much effort to this, for example by publishing a number of reports in the Technical Reports Series (TRS) for external beam dosimetry, most notably TRS-277 and more recently TRS-398. Both of these reports describe in detail the steps to be taken for absorbed dose determination in water and they are often referred to as 'dosimetry protocols'. Similar to TRS-277, it is expected that TRS-398 will be adopted or used as a model by a large number of countries as their national protocol. In 1996, the IAEA established a calibration service for low dose rate (LDR) 137 Cs brachytherapy sources, which is the most widely used source for treatment of gynecological cancer. To further enhance harmonization in brachytherapy dosimetry, the IAEA published in 1999 IAEA-TECDOC-1079 entitled 'Calibration of Brachytherapy Sources. Guidelines on Standardized Procedures for the Calibration of Brachytherapy Sources at Secondary Standard Dosimetry Laboratories (SSDLs) and Hospitals'. The report was well received and was distributed in a large number of copies to the members of the IAEA/WHO network of SSDLs and to medical physicists working with brachytherapy. The present report is an update of the aforementioned TECDOC. Whereas TECDOC-1079 described methods for calibrating brachytherapy sources with photon energies at or above those of 192 Ir, the current report has a wider scope in that it deals with standardization of calibration of all the most commonly used brachytherapy sources, including both photon and beta emitting sources. The latter sources have been in use for a few decades already, but their calibration methods have been unclear. Methods are also described for calibrating sources used in the rapidly growing field of cardiovascular angioplasty. In this application, irradiation of the vessel wall is done in an attempt to prevent restenosis after

Calibration Curves for Biological Dosimetry by Fluorescence In situ Hybridisation

International Nuclear Information System (INIS)

Stonati, L.; Durante, M.; Gensabella, G.; Gialanella, G.; Grossi, G.F.; Pugliese, M.; Scampoli, P.; Sgura, A.; Testa, A.; Tanzarella, C.

2001-01-01

Dose-response curves were measured for the induction of chromosomal aberrations in peripheral blood lymphocytes after acute exposure in vitro to 60 Co γ rays. Blood was obtained from four different healthy donors, and chromosomes were either observed at metaphase, following colcemid accumulation, or prematurely condensed by calyculin A. Cells were analysed in three different Italian laboratories. Chromosomes 1, 2, and 4 were painted, and simple-type interchanges between painted and non-painted chromosomes were scored in cells exposed in the dose range 0.1-3.0 Gy. The chemical-induced premature chromosome condensation method was also used combined with chromosome painting (chromosome 4 only) to determine calibration curves for high dose exposures (up to 20 Gy X rays). Calibration curves described in this paper will be used in our laboratories for biological dosimetry by fluorescence in situ hybridisation. (author)

Individual neutron dosimetry

International Nuclear Information System (INIS)

Mauricio, C.L.P.

1987-01-01

The most important concepts and development in individual neutron dosimetry are presented, especially the dosimetric properties of the albedo technique. The main problem in albedo dosimetry is to calibrate the dosemeter in the environs of each neutron source. Some of the most used calibration techniques are discussed. The IRD albedo dosemeter used in the routine neutron individual monitoring is described in detail. Its dosimetric properties and calibration methods are discussed. (Author) [pt

Radiochromic film dosimetry

International Nuclear Information System (INIS)

Xu Zhiyong

2002-01-01

Radiochromic film dosimetry was developed to measure ionization irradiation dose for industry and medicine. At this time, there are no comprehensive guideline on the medical application, calibration method and densitometer system for medicine. The review gives update on Radiochromic film dosimetry used for medicine, including principles, film model and material, characteristics, calibration method, scanning densitometer system and medical application

Comparison and uncertainty evaluation of different calibration protocols and ionization chambers for low-energy surface brachytherapy dosimetry

Energy Technology Data Exchange (ETDEWEB)

Candela-Juan, C., E-mail: ccanjuan@gmail.com [Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026 (Spain); Vijande, J. [Department of Atomic, Molecular, and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and Instituto de Física Corpuscular (UV-CSIC), Paterna 46980 (Spain); García-Martínez, T. [Radiation Oncology Department, Hospital La Ribera, Alzira 46600 (Spain); Niatsetski, Y.; Nauta, G.; Schuurman, J. [Elekta Brachytherapy, Veenendaal 3905 TH (Netherlands); Ouhib, Z. [Radiation Oncology Department, Lynn Regional Cancer Center, Boca Raton Community Hospital, Boca Raton, Florida 33486 (United States); Ballester, F. [Department of Atomic, Molecular, and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Perez-Calatayud, J. [Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026, Spain and Department of Radiotherapy, Clínica Benidorm, Benidorm 03501 (Spain)

2015-08-15

Purpose: A surface electronic brachytherapy (EBT) device is in fact an x-ray source collimated with specific applicators. Low-energy (<100 kVp) x-ray beam dosimetry faces several challenges that need to be addressed. A number of calibration protocols have been published for x-ray beam dosimetry. The media in which measurements are performed are the fundamental difference between them. The aim of this study was to evaluate the surface dose rate of a low-energy x-ray source with small field applicators using different calibration standards and different small-volume ionization chambers, comparing the values and uncertainties of each methodology. Methods: The surface dose rate of the EBT unit Esteya (Elekta Brachytherapy, The Netherlands), a 69.5 kVp x-ray source with applicators of 10, 15, 20, 25, and 30 mm diameter, was evaluated using the AAPM TG-61 (based on air kerma) and International Atomic Energy Agency (IAEA) TRS-398 (based on absorbed dose to water) dosimetry protocols for low-energy photon beams. A plane parallel T34013 ionization chamber (PTW Freiburg, Germany) calibrated in terms of both absorbed dose to water and air kerma was used to compare the two dosimetry protocols. Another PTW chamber of the same model was used to evaluate the reproducibility between these chambers. Measurements were also performed with two different Exradin A20 (Standard Imaging, Inc., Middleton, WI) chambers calibrated in terms of air kerma. Results: Differences between surface dose rates measured in air and in water using the T34013 chamber range from 1.6% to 3.3%. No field size dependence has been observed. Differences are below 3.7% when measurements with the A20 and the T34013 chambers calibrated in air are compared. Estimated uncertainty (with coverage factor k = 1) for the T34013 chamber calibrated in water is 2.2%–2.4%, whereas it increases to 2.5% and 2.7% for the A20 and T34013 chambers calibrated in air, respectively. The output factors, measured with the PTW chambers

Thermoluminescence albedo-neutron dosimetry

International Nuclear Information System (INIS)

Strand, T.; Storruste, A.

1986-10-01

The report discusses neutron detection with respect to dosimetry and compares different thermoluminescent dosimetry materials for neutron dosimetry. Construction and calibration of a thermoluminescence albedo neutron dosemeter, developed by the authors, is described

Validating dose rate calibration of radiotherapy photon beams through IAEA/WHO postal audit dosimetry service

International Nuclear Information System (INIS)

Jangda, A.Q.; Hussein, S.

2012-01-01

In external beam radiation therapy (EBRT), the quality assurance (QA) of the radiation beam is crucial to the accurate delivery of the prescribed dose to the patient. One of the dosimetric parameters that require monitoring is the beam output, specified as the dose rate on the central axis under reference conditions. The aim of this project was to validate dose rate calibration of megavoltage photon beams using the International Atomic Energy Agency (IAEA)/World Health Organisation (WHO) postal audit dosimetry service. Three photon beams were audited: a 6 MV beam from the low-energy linac and 6 and 18 MV beams from a dual high-energy linac. The agreement between our stated doses and the IAEA results was within 1% for the two 6 MV beams and within 2% for the 18 MV beam. The IAEA/WHO postal audit dosimetry service provides an independent verification of dose rate calibration protocol by an international facility. (author)

Validating dose rate calibration of radiotherapy photon beams through IAEA/WHO postal audit dosimetry service.

Science.gov (United States)

Jangda, Abdul Qadir; Hussein, Sherali

2012-05-01

In external beam radiation therapy (EBRT), the quality assurance (QA) of the radiation beam is crucial to the accurate delivery of the prescribed dose to the patient. One of the dosimetric parameters that require monitoring is the beam output, specified as the dose rate on the central axis under reference conditions. The aim of this project was to validate dose rate calibration of megavoltage photon beams using the International Atomic Energy Agency (IAEA)/World Health Organisation (WHO) postal audit dosimetry service. Three photon beams were audited: a 6 MV beam from the low-energy linac and 6 and 18 MV beams from a dual high-energy linac. The agreement between our stated doses and the IAEA results was within 1% for the two 6 MV beams and within 2% for the 18 MV beam. The IAEA/WHO postal audit dosimetry service provides an independent verification of dose rate calibration protocol by an international facility.

Clinical laboratory accreditation in India.

Science.gov (United States)

Handoo, Anil; Sood, Swaroop Krishan

2012-06-01

Test results from clinical laboratories must ensure accuracy, as these are crucial in several areas of health care. It is necessary that the laboratory implements quality assurance to achieve this goal. The implementation of quality should be audited by independent bodies,referred to as accreditation bodies. Accreditation is a third-party attestation by an authoritative body, which certifies that the applicant laboratory meets quality requirements of accreditation body and has demonstrated its competence to carry out specific tasks. Although in most of the countries,accreditation is mandatory, in India it is voluntary. The quality requirements are described in standards developed by many accreditation organizations. The internationally acceptable standard for clinical laboratories is ISO15189, which is based on ISO/IEC standard 17025. The accreditation body in India is the National Accreditation Board for Testing and Calibration Laboratories, which has signed Mutual Recognition Agreement with the regional cooperation the Asia Pacific Laboratory Accreditation Cooperation and with the apex cooperation the International Laboratory Accreditation Cooperation.

Establishment of a new calibration method of pencil ionization chamber for dosimetry in computed tomography

International Nuclear Information System (INIS)

Dias, Daniel Menezes

2010-01-01

Pencil ionization chambers are used for beam dosimetry in computed tomography equipment (CT). In this study, a new calibration methodology was established, in order to make the Calibration Laboratory of Instituto de Pesquisas Energeticas e Nucleares (LCI) suitable to international metrological standards, dealing with specific procedures for calibration of these chambers used in CT. Firstly, the setup for the new RQT radiation qualities was mounted, in agreement with IEC61267 from the International Electrotechnical Commission (IEC). After the establishment of these radiation qualities, a specific calibration methodology for pencil ionization chambers was set, according to Technical Report Series No. 457, from the International Atomic Energy Agency (IAEA), which describes particularities of the procedure to be followed by the Secondary Standard Dosimetry Laboratories (SSDL's), concerning to collimation and positioning related to the radiation beam. Initially, PPV (kV) measurements and the determination of copper additional filtrations were carried out, measuring the half value layers (HVL) recommended by the IEC 61267 standard, after that the RQT 8, RQT 9 and RQT 10 radiation quality references were established. For additional filters, aluminum and copper of high purity (around 99.9%) were used. RQT's in thickness of copper filters equivalent to the set 'RQR (Al) + Additional Filtration (Cu)' was directly found by an alternative methodology used to determine additional filtrations, which is a good option when RQR's have not the possibility of be setting up. With the establishment of this new methodology for the ionization pencil chambers calibration, the LCI is ready to calibrate these instruments according to the most recent international standards. Therefore, an improvement in calibration traceability, as well as in metrological services offered by IPEN to all Brazil is achieved. (author)

SPRT Calibration Uncertainties and Internal Quality Control at a Commercial SPRT Calibration Facility

Science.gov (United States)

Wiandt, T. J.

2008-06-01

The Hart Scientific Division of the Fluke Corporation operates two accredited standard platinum resistance thermometer (SPRT) calibration facilities, one at the Hart Scientific factory in Utah, USA, and the other at a service facility in Norwich, UK. The US facility is accredited through National Voluntary Laboratory Accreditation Program (NVLAP), and the UK facility is accredited through UKAS. Both provide SPRT calibrations using similar equipment and procedures, and at similar levels of uncertainty. These uncertainties are among the lowest available commercially. To achieve and maintain low uncertainties, it is required that the calibration procedures be thorough and optimized. However, to minimize customer downtime, it is also important that the instruments be calibrated in a timely manner and returned to the customer. Consequently, subjecting the instrument to repeated calibrations or extensive repeated measurements is not a viable approach. Additionally, these laboratories provide SPRT calibration services involving a wide variety of SPRT designs. These designs behave differently, yet predictably, when subjected to calibration measurements. To this end, an evaluation strategy involving both statistical process control and internal consistency measures is utilized to provide confidence in both the instrument calibration and the calibration process. This article describes the calibration facilities, procedure, uncertainty analysis, and internal quality assurance measures employed in the calibration of SPRTs. Data will be reviewed and generalities will be presented. Finally, challenges and considerations for future improvements will be discussed.

Perry Johnson Laboratory Accreditation, Inc. (PJLA)

Science.gov (United States)

2011-03-28

Accreditation Body, established in 1999, located in Troy, Michigan • Current Accreditation Programs– ISO / IEC 17025 :2005 and DoD ELAP, EPA NLLAP...Upcoming Accreditation Programs–Field Site Sampling & Measurement Organizations (FSMO)–TNI Volume 1 and 2, Reference Material Producers– ISO Guide...Testing/Calibration – 17025 -Testing–120 – 17025 -Calibration–191 – 17025 & DoD ELAP–14 (5 Pending) – 17025 and EPA NLLAP–1 – Pending

Personnel neutron dosimetry

International Nuclear Information System (INIS)

Hankins, D.

1982-04-01

This edited transcript of a presentation on personnel neutron discusses the accuracy of present dosimetry practices, requirements, calibration, dosemeter types, quality factors, operational problems, and dosimetry for a criticality accident. 32 figs

IAEA workshop/seminar on calibration procedures in dosimetry, Quito, 6-24 October 1986

International Nuclear Information System (INIS)

1987-01-01

The International Atomic Energy Agency in co-operation with the Ecuadorian Atomic Energy Commission organized a workshop and seminar on calibration procedures in dosimetry at the SSDL Quito, 6 to 24 October 1986. All calibration laboratories in the Latin American region were invited to participate. The purpose of the workshop were calibration exercises with therapy-level and protection-level secondary standards at various calibration qualities, discussions on progress made in the different SSDLs in the region and delivering lectures on pertinent subjects. A total of 15 Secondary Standards (10 therapy-level and 5 protection-level) were brought along by the participants and 35 calibration comparisons were performed with those having a valid calibration factor. Thirty-three determinations of calibration factors were performed for secondary standards not having had a calibration before. Twelve different calibration qualities were available (Cobalt-60 and X-rays) and Agency's Secondary Standards traceable to BIPM were the reference standards. The participants were divided into two working groups, each one week and each group into two sub-groups. Both irradiation bunkers were used simultaneously. The one houses the teletherapy Cobalt-60 unit and the protection-level Cobalt-60 irradiator, the other one the constant potential X-ray machine with maximum generating potential of 320 KV and suitable for both therapy-level as well as protection-level calibrations. Due to the heavy workload and limited time available some nightshifts were required to accomplish the requested calibration comparisons

Biological dosimetry of ionizing radiation: Evaluation of the dose with cytogenetic methodologies by the construction of calibration curves

Science.gov (United States)

Zafiropoulos, Demetre; Facco, E.; Sarchiapone, Lucia

2016-09-01

In case of a radiation accident, it is well known that in the absence of physical dosimetry biological dosimetry based on cytogenetic methods is a unique tool to estimate individual absorbed dose. Moreover, even when physical dosimetry indicates an overexposure, scoring chromosome aberrations (dicentrics and rings) in human peripheral blood lymphocytes (PBLs) at metaphase is presently the most widely used method to confirm dose assessment. The analysis of dicentrics and rings in PBLs after Giemsa staining of metaphase cells is considered the most valid assay for radiation injury. This work shows that applying the fluorescence in situ hybridization (FISH) technique, using telomeric/centromeric peptide nucleic acid (PNA) probes in metaphase chromosomes for radiation dosimetry, could become a fast scoring, reliable and precise method for biological dosimetry after accidental radiation exposures. In both in vitro methods described above, lymphocyte stimulation is needed, and this limits the application in radiation emergency medicine where speed is considered to be a high priority. Using premature chromosome condensation (PCC), irradiated human PBLs (non-stimulated) were fused with mitotic CHO cells, and the yield of excess PCC fragments in Giemsa stained cells was scored. To score dicentrics and rings under PCC conditions, the necessary centromere and telomere detection of the chromosomes was obtained using FISH and specific PNA probes. Of course, a prerequisite for dose assessment in all cases is a dose-effect calibration curve. This work illustrates the various methods used; dose response calibration curves, with 95% confidence limits used to estimate dose uncertainties, have been constructed for conventional metaphase analysis and FISH. We also compare the dose-response curve constructed after scoring of dicentrics and rings using PCC combined with FISH and PNA probes. Also reported are dose response curves showing scored dicentrics and rings per cell, combining

Quality control at the Regional Centre of Nuclear Sciences chemical dosimetry laboratory

Energy Technology Data Exchange (ETDEWEB)

Souza, Vivianne L.B. de; Melo, Roberto T. de; Silva, Danubia B. da; Pedroza, Eryka H.; Rodrigues, Kelia R.G.; Cunha, Manuela S. da; Figueiredo, Marcela D.C. de [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Oliveira, Aristides, E-mail: vlsouza@cnen.gov.b, E-mail: rtmelo@cnen.gov.b [Hospital de Cancer de Pernambuco, Recife, PE (Brazil)

2011-07-01

Standards for accreditation of laboratories as in ISO 9001 in section: 4.11 require inspection, measuring and equipment testing; likewise, IEC 17025: 2005 in section: 5.5.2 requires the equipment to be calibrated or verified before being put into use. In our laboratory, quality control is often accomplished by standards set done by the laboratory scientists themselves; however, at present, Hellma secondary calibration standards (4026 - Holmium oxide - Filters: F0, F2, F3, F4 and filter didymium - F7) have been used in order to verify if errors in the laboratory have been close to the 1-2% margin. Control graphs were made by using the results of synthetically prepared standards and standardized spectral calibration certificates. The set of secondary calibration standards permits to check the accuracy of the spectrophotometers used in research for both the absorbance in the visible spectrum (at 440, 465, 546, 590 and 635 nm wavelengths) and for the wavelengths (270, 280, 300, 320 nm) of the ultraviolet light. Filters (F0, F2, F3, F4 and F7) are stable and do not suffer the influence of temperature (the influence is negligible), the F0 filter was being used as a blank. The purpose is to verify whether the spectrometer needs adjustments, an important procedure to check absorbance stability, baseline flatness, slit width accuracy and stray radiation. The calibration tests are performed annually in our laboratory and recalibration of Hellma secondary standards is recommended every two years. The results show that the Chemical Dosimetry Laboratory in CRCN has a calibrated spectrophotometer and their synthetic standards for Fricke dosimetry could be used as an alternative method for testing the proficiency and competence of calibration laboratories in accordance with the regulations and standards. (author)

Calibration curves for biological dosimetry; Curvas de calibracion para dosimetria biologica

Energy Technology Data Exchange (ETDEWEB)

Guerrero C, C.; Brena V, M. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail cgc@nuclear.inin.mx

2004-07-01

The generated information by the investigations in different laboratories of the world, included the ININ, in which settles down that certain class of chromosomal leisure it increases in function of the dose and radiation type, has given by result the obtaining of calibrated curves that are applied in the well-known technique as biological dosimetry. In this work is presented a summary of the work made in the laboratory that includes the calibrated curves for gamma radiation of {sup 60} Cobalt and X rays of 250 k Vp, examples of presumed exposure to ionizing radiation, resolved by means of aberration analysis and the corresponding dose estimate through the equations of the respective curves and finally a comparison among the dose calculations in those people affected by the accident of Ciudad Juarez, carried out by the group of Oak Ridge, USA and those obtained in this laboratory. (Author)

Accreditation experience of radioisotope metrology laboratory of Argentina

Energy Technology Data Exchange (ETDEWEB)

Iglicki, A. [Laboratorio de Metrologia de Radioisotopos, Comision Nacional de Energia Atomica (Argentina)]. E-mail: iglicki@cae.cnea.gov.ar; Mila, M.I. [Laboratorio de Metrologia de Radioisotopos, Comision Nacional de Energia Atomica (Argentina)]. E-mail: mila@cae.cnea.gov.ar; Furnari, J.C. [Laboratorio de Metrologia de Radioisotopos, Comision Nacional de Energia Atomica (Argentina); Arenillas, P. [Laboratorio de Metrologia de Radioisotopos, Comision Nacional de Energia Atomica (Argentina); Cerutti, G. [Laboratorio de Metrologia de Radioisotopos, Comision Nacional de Energia Atomica (Argentina); Carballido, M. [Laboratorio de Metrologia de Radioisotopos, Comision Nacional de Energia Atomica (Argentina); Guillen, V. [Laboratorio de Metrologia de Radioisotopos, Comision Nacional de Energia Atomica (Argentina); Araya, X. [Laboratorio de Metrologia de Radioisotopos, Comision Nacional de Energia Atomica (Argentina); Bianchini, R. [Laboratorio de Metrologia de Radioisotopos, Comision Nacional de Energia Atomica (Argentina)

2006-10-15

This work presents the experience developed by the Radioisotope Metrology Laboratory (LMR), of the Argentine National Atomic Energy Commission (CNEA), as result of the accreditation process of the Quality System by ISO 17025 Standard. Considering the LMR as a calibration laboratory, services of secondary activity determinations and calibration of activimeters used in Nuclear Medicine were accredited. A peer review of the ({alpha}/{beta})-{gamma} coincidence system was also carried out. This work shows in detail the structure of the quality system, the results of the accrediting audit and gives the number of non-conformities detected and of observations made which have all been resolved.

Accreditation experience of radioisotope metrology laboratory of Argentina

International Nuclear Information System (INIS)

Iglicki, A.; Mila, M.I.; Furnari, J.C.; Arenillas, P.; Cerutti, G.; Carballido, M.; Guillen, V.; Araya, X.; Bianchini, R.

2006-01-01

This work presents the experience developed by the Radioisotope Metrology Laboratory (LMR), of the Argentine National Atomic Energy Commission (CNEA), as result of the accreditation process of the Quality System by ISO 17025 Standard. Considering the LMR as a calibration laboratory, services of secondary activity determinations and calibration of activimeters used in Nuclear Medicine were accredited. A peer review of the (α/β)-γ coincidence system was also carried out. This work shows in detail the structure of the quality system, the results of the accrediting audit and gives the number of non-conformities detected and of observations made which have all been resolved

Calibration of photon and beta ray sources used in brachytherapy. Guidelines on standardized procedures at Secondary Standards Dosimetry Laboratories (SSDLs) and hospitals

International Nuclear Information System (INIS)

2002-03-01

It has generally been recognized that international harmonization in radiotherapy dosimetry is essential. Consequently, the IAEA has given much effort to this, for example by publishing a number of reports in the Technical Reports Series (TRS) for external beam dosimetry, most notably TRS-277 and more recently TRS-398. Both of these reports describe in detail the steps to be taken for absorbed dose determination in water and they are often referred to as 'dosimetry protocols'. Similar to TRS-277, it is expected that TRS-398 will be adopted or used as a model by a large number of countries as their national protocol. In 1996, the IAEA established a calibration service for low dose rate (LDR) 137 Cs brachytherapy sources, which is the most widely used source for treatment of gynecological cancer. To further enhance harmonization in brachytherapy dosimetry, the IAEA published in 1999 IAEA-TECDOC-1079 entitled 'Calibration of Brachytherapy Sources. Guidelines on Standardized Procedures for the Calibration of Brachytherapy Sources at Secondary Standard Dosimetry Laboratories (SSDLs) and Hospitals'. The report was well received and was distributed in a large number of copies to the members of the IAEA/WHO network of SSDLs and to medical physicists working with brachytherapy. The present report is an update of the aforementioned TECDOC. Whereas TECDOC-1079 described methods for calibrating brachytherapy sources with photon energies at or above those of 192 Ir, the current report has a wider scope in that it deals with standardization of calibration of all the most commonly used brachytherapy sources, including both photon and beta emitting sources. The latter sources have been in use for a few decades already, but their calibration methods have been unclear. Methods are also described for calibrating sources used in the rapidly growing field of cardiovascular angioplasty. In this application, irradiation of the vessel wall is done in an attempt to prevent restenosis after

Pathway to Accreditation of Medical laboratories in Mauritius

African Journals Online (AJOL)

Nafiisah

The issue of quality management systems and accreditation is gaining increasing ... MAURITAS is to provide accreditation services to testing/calibration ... carries out its own, internal, audits on a regular basis and record the results for scrutiny ...

Poster - 16: Time-resolved diode dosimetry for in vivo proton therapy range verification: calibration through numerical modeling

Energy Technology Data Exchange (ETDEWEB)

Toltz, Allison; Hoesl, Michaela; Schuemann, Jan; Seuntjens, Jan; Lu, Hsiao-Ming; Paganetti, Harald [McGill University, Harvard University, Massachusetts General Hospital, McGill University, Massachusetts General Hospital, Massachusetts General Hospital (United States)

2016-08-15

Purpose: A method to refine the implementation of an in vivo, adaptive proton therapy range verification methodology was investigated. Simulation experiments and in-phantom measurements were compared to validate the calibration procedure of a time-resolved diode dosimetry technique. Methods: A silicon diode array system has been developed and experimentally tested in phantom for passively scattered proton beam range verification by correlating properties of the detector signal to the water equivalent path length (WEPL). The implementation of this system requires a set of calibration measurements to establish a beam-specific diode response to WEPL fit for the selected ‘scout’ beam in a solid water phantom. This process is both tedious, as it necessitates a separate set of measurements for every ‘scout’ beam that may be appropriate to the clinical case, as well as inconvenient due to limited access to the clinical beamline. The diode response to WEPL relationship for a given ‘scout’ beam may be determined within a simulation environment, facilitating the applicability of this dosimetry technique. Measurements for three ‘scout’ beams were compared against simulated detector response with Monte Carlo methods using the Tool for Particle Simulation (TOPAS). Results: Detector response in water equivalent plastic was successfully validated against simulation for spread out Bragg peaks of range 10 cm, 15 cm, and 21 cm (168 MeV, 177 MeV, and 210 MeV) with adjusted R{sup 2} of 0.998. Conclusion: Feasibility has been shown for performing calibration of detector response for a given ‘scout’ beam through simulation for the time resolved diode dosimetry technique.

A suitability study of the fission product phantom and the bottle manikin absorption phantom for calibration of in vivo bioassay equipment for the DOELAP accreditation testing program

International Nuclear Information System (INIS)

Olsen, P.C.; Lynch, T.P.

1991-08-01

Pacific Northwest laboratory (PNL) conducted an intercomparison study of the Fission Product phantom and the bottle manikin absorption (BOMAB) phantom for the US Department of Energy (DOE) to determine the consistency of calibration response of the two phantoms and their suitability for certification and use under a planned bioassay laboratory accreditation program. The study was initiated to determine calibration factors for both types of phantoms and to evaluate the suitability of their use in DOE Laboratory Accreditation Program (DOELAP) round-robin testing. The BOMAB was found to be more appropriate for the DOELAP testing program. 9 refs., 9 figs., 9 tabs

Radiochromic film calibration for dosimetry in computed tomography tests

International Nuclear Information System (INIS)

Costa, K. C.; Prata M, A.; Ladino G, A. M.; Costa, K. L.

2017-10-01

Radiochromic film applications in dosimetry have become increasingly significant for studies on radiotherapy and diagnostic tests. Due to sensitivity to exposure to ionizing radiation, radiochromic films are commonly used to obtain dose distribution maps. The objective of this study is to obtain the calibration curves of the radiographic film for exposure with X-ray beam in a computerized tomography (CT) scanner to realize measures of typical doses found in radiodiagnosis tests. It was used Gafchromic Xr-AQ2 film, which shows little sensitivity to visible light and a response in the range of 0.1 to 20 Gy for X-ray beam in a tube voltage supply range ranging from 20 kV to 200 kV. In the experiments, a head polymethylmethacrylate (PMMA) phantom, with a cylindrical shape with five openings was used. This phantom was placed in the CT scanner isocenter and radiochromic film strips were placed into two openings. The irradiations were performed in a Toshiba Asteion scanner that allows making acquisitions in helical mode. The central slice of the head phantom was irradiated to obtain the values of air kerma in PMMA measured with a pencil ionization chamber. Thereafter, radiochromic film strips were placed into the central and one peripheral opening and 10 cm long scans of the central region of the phantom were carried out with feed voltage of 120 kV. The strips irradiated with different X-ray tube currents were scanned and processed using the ImageJ software to obtain the intensity values resulting from the absorbed radiation by optical density analysis. The calibration curves were obtained for both region, central and peripheral corresponding to the values of air kerma in PMMA measured with ionization chamber. With the curves in hand, CT experiments with applied beams can use radiochromic films as a dosimetry method and then seek the generation of images with lower dose deposition and higher diagnostic quality. (Author)

Radiochromic film calibration for dosimetry in computed tomography tests

Energy Technology Data Exchange (ETDEWEB)

Costa, K. C.; Prata M, A. [Federal Center for Technological Education of Minas Gerais, Biomedical Engineering Center, Av. Amazonas 5253, Nova Suica, 30421-169 Belo Horizonte, Minas Gerais (Brazil); Ladino G, A. M. [Federal University of Minas Gerais, Department of Nuclear Engineering, Av. Antonio Carlos 6627, Pampulha, 31270-90 Belo Horizonte, Minas Gerais (Brazil); Costa, K. L., E-mail: apratabhz@gmail.com [University of Itauna, Medicine Department, Rodovia Mg 431 Km 45 s/n, El Dorado, 35680-142 Itauna, Minas Gerais (Brazil)

2017-10-15

Radiochromic film applications in dosimetry have become increasingly significant for studies on radiotherapy and diagnostic tests. Due to sensitivity to exposure to ionizing radiation, radiochromic films are commonly used to obtain dose distribution maps. The objective of this study is to obtain the calibration curves of the radiographic film for exposure with X-ray beam in a computerized tomography (CT) scanner to realize measures of typical doses found in radiodiagnosis tests. It was used Gafchromic Xr-AQ2 film, which shows little sensitivity to visible light and a response in the range of 0.1 to 20 Gy for X-ray beam in a tube voltage supply range ranging from 20 kV to 200 kV. In the experiments, a head polymethylmethacrylate (PMMA) phantom, with a cylindrical shape with five openings was used. This phantom was placed in the CT scanner isocenter and radiochromic film strips were placed into two openings. The irradiations were performed in a Toshiba Asteion scanner that allows making acquisitions in helical mode. The central slice of the head phantom was irradiated to obtain the values of air kerma in PMMA measured with a pencil ionization chamber. Thereafter, radiochromic film strips were placed into the central and one peripheral opening and 10 cm long scans of the central region of the phantom were carried out with feed voltage of 120 kV. The strips irradiated with different X-ray tube currents were scanned and processed using the ImageJ software to obtain the intensity values resulting from the absorbed radiation by optical density analysis. The calibration curves were obtained for both region, central and peripheral corresponding to the values of air kerma in PMMA measured with ionization chamber. With the curves in hand, CT experiments with applied beams can use radiochromic films as a dosimetry method and then seek the generation of images with lower dose deposition and higher diagnostic quality. (Author)

A method for automating calibration and records management for instrumentation and dosimetry

Energy Technology Data Exchange (ETDEWEB)

O`Brien, J.M. Jr.; Rushton, R.O.; Burns, R.E. Jr. [Atlan-Tech, Inc., Roswell, GA (United States)

1993-12-31

Current industry requirements are becoming more stringent on quality assurance records and documentation for calibration of instruments and dosimetry. A novel method is presented here that will allow a progressive automation scheme to be used in pursuit of that goal. This concept is based on computer-controlled irradiators that can act as stand-alone devices or be interfaced to other components via a computer local area network. In this way, complete systems can be built with modules to create a records management system to meet the needs of small laboratories or large multi-building calibration groups. Different database engines or formats can be used simply by replacing a module. Modules for temperature and pressure monitoring or shipping and receiving can be added, as well as equipment modules for direct IEEE-488 interface to electrometers and other instrumentation.

A method for automating calibration and records management for instrumentation and dosimetry

International Nuclear Information System (INIS)

O'Brien, J.M. Jr.; Rushton, R.O.; Burns, R.E. Jr.

1993-01-01

Current industry requirements are becoming more stringent on quality assurance records and documentation for calibration of instruments and dosimetry. A novel method is presented here that will allow a progressive automation scheme to be used in pursuit of that goal. This concept is based on computer-controlled irradiators that can act as stand-alone devices or be interfaced to other components via a computer local area network. In this way, complete systems can be built with modules to create a records management system to meet the needs of small laboratories or large multi-building calibration groups. Different database engines or formats can be used simply by replacing a module. Modules for temperature and pressure monitoring or shipping and receiving can be added, as well as equipment modules for direct IEEE-488 interface to electrometers and other instrumentation

The dosimetry programme of the IAEA

International Nuclear Information System (INIS)

1987-01-01

Describes the activities of the IAEA's Dosimetry Laboratory which provides calibration and comparison services for secondary standard dosimetry laboratories (SSDLs) of Member States. In addition, a joint IAEA/WHO postal dosimetry service has been established for radiotherapy centers. The International Measurement System and the calibration ''chain'' from measurement standard instruments of the International Bureau of Weights and Measurements (BIPM) through the primary and secondary standards to the dosimeters of the users are presented as well

Accreditation of laboratories in the field of radiation protection

International Nuclear Information System (INIS)

Galjanic, S.; Franic, Z.

2005-01-01

This paper gives a review of requirements and procedures for the accreditation of test and calibration laboratories in the field of radiation protection, paying particular attention to Croatia. General requirements to be met by a testing or calibration laboratory to be accredited are described in the standard HRN EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories. The quality of a radiation protection programme can only be as good as the quality of the measurements made to support it. Measurement quality can be assured by participation in measurement assurance programmes that evaluate the appropriateness of procedures, facilities, and equipment and include periodic checks to assure adequate performance. These also include internal consistency checks, proficiency tests, intercomparisons and site visits by technical experts to review operations. In Croatia, laboratories are yet to be accredited in the field of radiation protection. However, harmonisation of technical legislation with the EU legal system will require some changes in laws and regulations in the field of radiation protection, including the ones dealing with the notification of testing laboratories and connected procedures. Regarding the notification procedures for testing laboratories in Croatia, in the regulated area, the existing accreditation infrastructure, i.e. Croatian Accreditation Agency is ready for its implementation, as it has already established and further developed a consistent accreditation system, compatible with international requirements and procedures.(author)

Calibration of personal dosemeters in terms of the ICRU operational quantities

International Nuclear Information System (INIS)

McDonald, J.C.; Hertel, N.E.

1992-01-01

The International Commission on Radiological Units and Measurements (ICRU) has defined several new operational quantities for radiation protection purposes. The quantities to be used for personal monitoring are defined at depths in the human body. Because these quantities are impossible to measure directly, the ICRU has recommended that personal dosimeters should be calibrated under simplified conditions on an appropriate phantom, such as the ICRU sphere. The U.S. personal dosimetry accreditation programs make use of a 30 x 30 x 15 cm polymethylmethacrylate (PMMA) phantom; therefore it is necessary to relate the response of dosimeters calibrated on this phantom to the ICRU operational quantities. Calculations of the conversion factors to compute dosimeter response in terms of the operational quantities have been performed using the code MCNP. These calculations have also been compared to experimental measurements using thermoluminescent (TLD) detectors. (author)

Calibration of personal dosemeters in terms of the ICRU operational quantities

International Nuclear Information System (INIS)

McDonald, J.C.; Hertel, N.E.

1992-05-01

The International Commission on Radiological Units and Measurements (ICRU) has defined several new operational quantities for radiation protection purposes. The quantities to be used for personal monitoring are defined at depths in the human body. Because these quantities are impossible to measure directly, the ICRU has recommended that personal dosemeters should be calibrated under simplified conditions on an appropriate phantom, such as the ICRU sphere. The US personal dosimetry accreditation programs make use of a 30 x 30 x 15 cm polymethymethacrylate (PMMA) phantom, therefore it is necessary to relate the response of dosemeters calibrated on this phantom to the ICRU operational quantities. Calculations of the conversion factors to compute dosemeter response in terms of the operational quantities have been performed using the code MCNP. These calculations have also been compared to experimental measurements using thermoluminescent (TLD) detectors

Establishing and maintaining a measurement uncertainty programme at the RPII dosimetry and calibration service

International Nuclear Information System (INIS)

Spain, D.; Currivan, L.; Fitzgerald, H.; Pollard, D.

2005-01-01

Full text: At the Dosimetry and Calibration Service of the Radiological Protection Institute of Ireland (RPII) approximately 70,000 thermoluminescent dosemeters (TLDs) are issued each year to monitor occupationally exposed workers in Ireland. In addition the service offers a calibration service for radiation survey meters, contamination monitors and electronic personal dosemeters. In order to meet the requirements of ISO/IEC 17025, it is necessary to quantify the uncertainty of measurement using well defined concepts and to maintain an up to date estimate. In this work it is shown how the measurement uncertainty in the Dosimetry and Calibration Service has been estimated. When estimating the uncertainty of measurement, all uncertainty components which are of importance in the given situation are taken into account. The combined uncertainty of the system is determined by considering a number of systematic and random errors. The analysis will include assumptions made and these have been documented and justified. Components of uncertainty were determined in accordance with such documents as IEC 61066, Guide to Expression of Uncertainty in Measurement, and the National Physical Laboratory Measurement Good Practice Guide No. 11, as appropriate. Results of intercomparisons are also presented, which adds confidence to the uncertainty estimate. Although a great deal of work is involved is estimating uncertainty in both laboratories it is felt that a reasonable estimate of measurement uncertainty has been achieved given the available information. Furthermore, in keeping with the laboratory's commitment to continuous improvement, it is necessary to evaluate periodically the measurement uncertainties associated with the relevant procedures and a programme for the future is outlined. (author)

Principles for the design and calibration of radiation protection dosemeters for operational and protection quantities for eye lens dosimetry

International Nuclear Information System (INIS)

Bordy, J. M.; Gualdrini, G.; Daures, J.; Mariotti, F.

2011-01-01

The work package two of the ORAMED project-Collaborative Project (2008-2011) supported by the European Commission within its seventh Framework Programme-is devoted to the study of the eye lens dosimetry. A first approach is to implement the use of H p (3) by providing new sets of conversion coefficients and well suited calibration and type test procedures. This approach is presented in other papers in the proceedings of this conference. Taking into account that the eye lens is an organ close to the surface of the body, another approach would be to directly estimate the absorbed dose to the eye lens, D lens,est through a special calibration procedure although this quantity is not directly measurable. This paper is a methodological paper that tries to identify the critical aspects of a dosimetry in terms of D lens . (authors)

Personal dosimetry performance testing in the United States

International Nuclear Information System (INIS)

Soares, Christopher G.

2008-01-01

The basis for personal dosimetry performance testing in the United States is ANSI/HPS N13.11. Now in it's fourth edition, this standard has been in place since 1983. Testing under this standard is administered by the National Voluntary Laboratory Accreditation Program (NVLAP), and accreditation of dosimetry processors under this program is required by U.S. Nuclear Regulatory Commission (NRC) regulations. The U.S. Department of Energy (DOE) also maintains a testing program for its laboratories and contractors, administered by the Department of Energy Laboratory Accreditation Program (DOELAP). One of the goals of this current revision was the modification of ANSI/HPS N13.11 to allow acceptance by both testing programs in order to bring harmonization to U.S. personal dosemeter performance testing. The testing philosophy of ANSI/HPS N13.11 has always combined elements of type testing and routine performance testing and is thus different from the testing philosophy used in the rest of the world. In this paper, the history of performance testing in the U.S. is briefly reviewed. Also described is the revision that produced the fourth edition of this standard, which has taken place over the last three years (2005-2008) by a working group representing national standards laboratories, government laboratories, the military, dosimetry vendors, universities and the nuclear power industry. (author)

Skin dosimetry - radiological protection aspects of skin dosimetry

International Nuclear Information System (INIS)

Dennis, J.A.

1991-01-01

Following a Workshop in Skin Dosimetry, a summary of the radiological protection aspects is given. Aspects discussed include routine skin monitoring and dose limits, the need for careful skin dosimetry in high accidental exposures, techniques for assessing skin dose at all relevant depths and the specification of dose quantities to be measured by personal dosemeters and the appropriate methods to be used in their calibration. (UK)

Development of a calibration protocol for quantitative imaging for molecular radiotherapy dosimetry

International Nuclear Information System (INIS)

Wevrett, J.; Fenwick, A.; Scuffham, J.; Nisbet, A.

2017-01-01

Within the field of molecular radiotherapy, there is a significant need for standardisation in dosimetry, in both quantitative imaging and dosimetry calculations. Currently, there are a wide range of techniques used by different clinical centres and as a result there is no means to compare patient doses between centres. To help address this need, a 3 year project was funded by the European Metrology Research Programme, and a number of clinical centres were involved in the project. One of the required outcomes of the project was to develop a calibration protocol for three dimensional quantitative imaging of volumes of interest. Two radionuclides were selected as being of particular interest: iodine-131 ( 131 I, used to treat thyroid disorders) and lutetium-177 ( 177 Lu, used to treat neuroendocrine tumours). A small volume of activity within a scatter medium (water), representing a lesion within a patient body, was chosen as the calibration method. To ensure ease of use in clinical centres, an “off-the-shelf” solution was proposed – to avoid the need for in-house manufacturing. The BIODEX elliptical Jaszczak phantom and 16 ml fillable sphere were selected. The protocol was developed for use on SPECT/CT gamma cameras only, where the CT dataset would be used to correct the imaging data for attenuation of the emitted photons within the phantom. The protocol corrects for scatter of emitted photons using the triple energy window correction technique utilised by most clinical systems. A number of clinical systems were tested in the development of this protocol, covering the major manufacturers of gamma camera generally used in Europe. Initial imaging was performed with 131 I and 177 Lu at a number of clinical centres, but due to time constraints in the project, some acquisitions were performed with 177 Lu only. The protocol is relatively simplistic, and does not account for the effects of dead-time in high activity patients, the presence of background activity

Preliminary measurements of the establishment of a quality control programme for the activimeter calibration reference system

International Nuclear Information System (INIS)

Martins, Elaine W.; Potiens, Maria da Penha A.

2009-01-01

The nuclear medicine techniques efficiency and safety depends on, beside other factors, a quality control programme, mainly regards to the nuclides activimeter utilization. The Calibration Laboratory of IPEN uses as a work standard, a tertiary standard system Capintec, calibrated at the Accredited Dosimetry Calibration Laboratory of the Medical radiation Research Center - University of Wisconsin. In this work, as preliminary measurements to establish a quality control programme for the activimeter calibration procedures, initially the repeatability and reproducibility (long term stability) tests were performed using a sealed check source of 133 Ba. Later on, to complete this quality control programme other check sources ( 137 Cs, 57 Co, 60 Co) will be used to perform the same tests. A series of 80 experiments of 10 measurements each has been carried out. The reference system showed a good behaviour to the repeatability test, considering the tolerance limits of 5%. The percent deviations of all tested sources in the activity measurements were lower 1% to 133 Ba. (author)

Determining the lower limit of detection for personnel dosimetry systems

International Nuclear Information System (INIS)

Roberson, P.L.; Carlson, R.D.

1992-01-01

A simple method for determining the lower limit of detection (LLD) for personnel dosimetry systems is described. The method relies on the definition of a critical level and a detection level. The critical level is the signal level above which a result has a small probability of being due to a fluctuation of the background. All results below the critical level should not be reported as an indication of a positive result. The detection level is the net signal level (i.e., dose received) above which there is a high confidence that a true reading will be detected and reported as a qualitatively positive result. The detection level may be identified as the LLD. A simple formula is derived to allow the calculation of the LLD under various conditions. This type of formula is being used by the Department of Energy Laboratory Accreditation Program (DOELAP) for personnel dosimetry. Participants in either the National Voluntary Laboratory Accreditation Program (NVLAP) for personnel dosimetry or DOELAP can use performance test results along with a measurement of background levels to estimate the LLDs for their dosimetry system. As long as they maintain their dosimetry system such that the LLDs are less than half the lower limit of the NVLAP or DOELAP test exposure ranges, dosimetry laboratories can avoid testing failures due to poor performance at very low exposures

Calibration of activation detectors in a monoenergetic neutron beam. Contribution to criticality dosimetry

International Nuclear Information System (INIS)

Massoutie, Martine.

1981-05-01

Activation detectors have been calibrated for critical dosimetry applications. Measurements are made using a monoenergetic neutron flux. 14 MeV neutrons obtained par (D-T) reaction are produced by 150 kV accelerator. Neutron flux determined by different methods leads us to obtain an accuracy better than 6%. The present dosimetric system (Activation Neutron Spectrometer - SNAC) gives few informations in the (10 keV - 2 MeV) energetic range. The system has been improved and modified so that SNAC detectors must be read out by gamma spectrometer [fr

Statistical analysis of personal dosimetry of exposed workers

International Nuclear Information System (INIS)

Sanchez Munoz, F. J.; Alejo Luque, L.; Mas Munoz, I.; Serrada Hierro, A.

2013-01-01

The dosimetry centers accredited by the Nuclear Safety Council (CSN) normally report overcoming legal limits, or some fraction thereof, but do not provide comparative dosimetric criteria indicating if assigned to a given dose is large TPE or small relative to that of their peers. In order to help to resolve the difficulties mentioned ds, it has developed an application that statistically processes the dosimetric data provided by the National Dosimetry Center. (Author)

Technical basis document for internal dosimetry

International Nuclear Information System (INIS)

Hickman, D.P.

1991-01-01

This document provides the technical basis for the Chem-Nuclear Geotech (Geotech) internal dosimetry program. Geotech policy describes the intentions of the company in complying with radiation protection standards and the as low as reasonably achievable (ALARA) program. It uses this policy and applicable protection standards to derive acceptable methods and levels of bioassay to assure compliance. The models and computational methods used are described in detail within this document. FR-om these models, dose- conversion factors and derived limits are computed. These computations are then verified using existing documentation and verification information or by demonstration of the calculations used to obtain the dose-conversion factors and derived limits. Recommendations for methods of optimizing the internal dosimetry program to provide effective monitoring and dose assessment for workers are provided in the last section of this document. This document is intended to be used in establishing an accredited dosimetry program in accordance with expected Department of Energy Laboratory Accreditation Program (DOELAP) requirements for the selected radionuclides provided in this document, including uranium mill tailing mixtures. Additions and modifications to this document and procedures derived FR-om this document are expected in the future according to changes in standards and changes in programmatic mission

Evaluation of uncertainty in dosimetry of irradiator system

International Nuclear Information System (INIS)

Santos, Gelson P.; Potiens, Maria P.A.; Vivolo, Vitor

2005-01-01

This paper describes the study of uncertainties in the estimates of dosimetry irradiator system STS 0B85 of LCI IPEN/CNEN-SP. This study is relevant for determination of best measurement capability when the laboratory performs routine calibrations of measuring radiation next the optimal measures designed to radioprotection. It is also a requirement for obtaining the accreditation of the laboratory by the INMETRO. For this dosimetry was used a reference system of the laboratory composed of a electrometer and a spherical ionization chamber of 1 liter. Measurements were made at five distances selected so to include the whole range of the optical bench tests and using three attenuators filters so as to extend the measurement capability. The magnitude used for evaluation was the rate of air kerma for 1 37C s and 6 0C o beams. Were carried out four series of measurements. It was verified the inverse square law to these series and their sets of uncertainty. Unfiltered, with one and two filters series showed good agreement with the inverse square low and the maximum uncertainty obtained was approximately 1.7%. In series with all the filters was a major deviation of the inverse square law and wide increase in uncertainty to measurements at the end of the optical bench

Optimization of SPECT calibration for quantification of images applied to dosimetry with iodine-131

International Nuclear Information System (INIS)

Carvalho, Samira Marques de

2018-01-01

SPECT systems calibration plays an essential role in the accuracy of the quantification of images. In this work, in its first stage, an optimized SPECT calibration method was proposed for 131 I studies, considering the partial volume effect (PVE) and the position of the calibration source. In the second stage, the study aimed to investigate the impact of count density and reconstruction parameters on the determination of the calibration factor and the quantification of the image in dosimetry studies, considering the reality of clinical practice in Brazil. In the final step, the study aimed evaluating the influence of several factors in the calibration for absorbed dose calculation using Monte Carlo simulations (MC) GATE code. Calibration was performed by determining a calibration curve (sensitivity versus volume) obtained by applying different thresholds. Then, the calibration factors were determined with an exponential function adjustment. Images were performed with high and low counts densities for several source positions within the simulator. To validate the calibration method, the calibration factors were used for absolute quantification of the total reference activities. The images were reconstructed adopting two approaches of different parameters, usually used in patient images. The methodology developed for the calibration of the tomographic system was easier and faster to implement than other procedures suggested to improve the accuracy of the results. The study also revealed the influence of the location of the calibration source, demonstrating better precision in the absolute quantification considering the location of the target region during the calibration of the system. The study applied in the Brazilian thyroid protocol suggests the revision of the calibration of the SPECT system, including different positions for the reference source, besides acquisitions considering the Signal to Noise Ratio (SNR) of the images. Finally, the doses obtained with the

Dosimetry through the Secondary Laboratory of Dosimetric Calibration of Mexico; Dosimetria a traves del Laboratorio Secundario de Calibracion Dosimetrica de Mexico

Energy Technology Data Exchange (ETDEWEB)

Tovar M, V.M.; Alvarez R, J.T.; Medina O, V.P.; Vergara M, F.; Anaya M, R.; Cejudo A, J.; Salinas L, B. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

2004-07-01

In the beginnings of the sixty years an urgent necessity is presented mainly in the developing countries, of improving in important form the accuracy in the dosimetry of external faces in therapy of radiations (radiotherapy centers), mainly in the calibration of ''clinical dosemeters''. In 1976 the International Atomic Energy Agency, (IAEA), and the World Health Organization, (WHO), they carried out a mutual agreement with regard to the establishment and operation of a net of Secondary Patron Laboratories of Dosimetry, (LSCD). The necessity to establish measure patterns in the field of the dosimetry of the ionizing radiations, is necessary, to have an accuracy but high in the dosimetry of the radiation beams in therapy which is highly dependent of the dose given to the tumor of those patient with cancer. Similar levels of accuracy are required in protection measures to the radiation with an acceptable smaller accuracy, however, when the personal dosemeters are used to determine the doses received by the individuals under work conditions, such mensurations in therapy of radiations and radiological protection will have traceability through a chain of comparisons to primary or national patterns. The traceability is necessary to assure the accuracy and acceptability of the dosimetric measures, as well as, the legal and economic implications. The traceability is also necessary in the dosimetry of high dose like in the sterilization of different products. The main function of the LSCD is to provide a service in metrology of ionizing radiations, maintaining the secondary or national patterns, which have a traceability to the International System of measures, which is based for if same in the comparison of patterns in the Primary Laboratories of Dosimetry (LPD) under the auspice of the International Office of Weights and Measure (BIPM). The secondary and national patterns in the LSCD constitute in Mexico, the national patterns of the magnitudes in the

NVLAP calibration laboratory program

Energy Technology Data Exchange (ETDEWEB)

Cigler, J.L.

1993-12-31

This paper presents an overview of the progress up to April 1993 in the development of the Calibration Laboratories Accreditation Program within the framework of the National Voluntary Laboratory Accreditation Program (NVLAP) at the National Institute of Standards and Technology (NIST).

NVLAP calibration laboratory program

International Nuclear Information System (INIS)

Cigler, J.L.

1993-01-01

This paper presents an overview of the progress up to April 1993 in the development of the Calibration Laboratories Accreditation Program within the framework of the National Voluntary Laboratory Accreditation Program (NVLAP) at the National Institute of Standards and Technology (NIST)

Influence of different types of phantoms on the calibration of dosemeters for eye lens dosimetry

International Nuclear Information System (INIS)

Yoshitomi, H.; Kowatari, M.

2016-01-01

Both a cylinder and a slab phantom have been recommended to be used as calibration phantoms for eye lens dosimetry in the International Atomic Energy Agency TECDOC. This study describes investigations on the influence of the type of phantom on the calibration of dosemeters. In order to fulfil the purpose, backscatter radiation from practically used water-filled phantoms was evaluated by calculations and experiments. For photons, the calculations showed that the cylinder phantom had 10 % lower backscattered effect at maximum than a slab phantom, and simulated well the backscattered effect of the human head or neck to within ±10 %. The irradiation results of non-filtered optically stimulated luminescence and radio-photoluminescence glass dosemeters indicated that the differences of the calibration factors between the two types of phantoms were up to 20 and 10 %, respectively, reflecting the response to backscattered photons. For electrons, no difference was found between the two types of phantoms. (authors)

Secondary calibration laboratory for dosimetry in levels of therapy at the University of Santiago

International Nuclear Information System (INIS)

Gomez Rodriguez, F.; Gonzalez Castano, D. M.; Pazos Alvarez, A.

2011-01-01

A basic inherent benefits provided by the existence of a traceability chain radiation in any application, add the legal requirement for hospitals as pointed to by the RO. 1566/1998, which sets quality standards in radiotherapy. The decree attributed to hospital specialists radio physics in article 10 the responsibility for determining the acceptance and initial reference state of radiation generating equipment for therapeutic purposes, and the establishment and implementation of quality control programs associated and technical and physical aspects of radiation dosimetry. Different international organizations such as ICRU and IAEA recommendations on maintaining the accuracy of the dose delivered to patients in general, should be placed at least 5% considering the whole chain irradiation. In order to achieve this purpose it is necessary to establish programs of quality control and calibration dosimetric regular basis. The protocol of the IAEA TRS398 recommended dose calibration in water because it is a quantity of interest closest to clinical use and allows a relative uncertainty in the calibration environment reduced to 1%.. (Author)

Accreditation - ISO/IEC 17025

Science.gov (United States)

Kaus, Rüdiger

This chapter gives the background on the accreditation of testing and calibration laboratories according to ISO/IEC 17025 and sets out the requirements of this international standard. ISO 15189 describes similar requirements especially tailored for medical laboratories. Because of these similarities ISO 15189 is not separately mentioned throughout this lecture.

The calibration method for personal dosimetry system in photon and neutron radiation fields

Energy Technology Data Exchange (ETDEWEB)

Trousil, J; Plichta, J [CSOD, Prague (Czech Republic); Nikodemova, D [SOD, Bratislava (Slovakia)

1996-12-31

The type testing of dosimetry system was performed with standard photon radiation fields within the energy range 15 keV to 1.25 MeV and electron radiation fields within the range 0.2 MeV to 3 MeV. For type testing of neutron dosimeters {sup 252}Cf and {sup 241}Am-Be radionuclide neutron sources was used, as well as a 14 MeV neutron generator. The neutron sources moderated by various moderating and absorbing materials was also used. The routine calibration of individual photon dosemeters was carried out using a {sup 137}Cs calibration source in the air kerma quality in the dose range 0.2 mGy to 6 Gy. The type testing of neutron dosemeters was performed in collaboration with Nueherberg laboratory on neutron generator with neutron energies -.57; 1.0;; 5.3 and 15.1 MeV. The fading and angular dependence testing was also included in the tests of both dosemeter systems. (J.K.).

Dosimetry of ionizing radiation

International Nuclear Information System (INIS)

Musilek, L.; Seda, J.; Trousil, J.

1992-01-01

The publication deals with a major field of ionizing radiation dosimetry, viz., integrating dosimetric methods, which are the basic means of operative dose determination. It is divided into the following sections: physical and chemical effects of ionizing radiation; integrating dosimetric methods for low radiation doses (film dosimetry, nuclear emulsions, thermoluminescence, radiophotoluminescence, solid-state track detectors, integrating ionization dosemeters); dosimetry of high ionizing radiation doses (chemical dosimetric methods, dosemeters based on the coloring effect, activation detectors); additional methods applicable to integrating dosimetry (exoelectron emission, electron spin resonance, lyoluminescence, etc.); and calibration techniques for dosimetric instrumentation. (Z.S.). 422 refs

Sixth symposium on neutron dosimetry

International Nuclear Information System (INIS)

1987-01-01

This booklet contains all abstracts of papers presented in 13 sessions. Main topics: Cross sections and Kerma factors; analytical radiobiology; detectors for personnel monitoring; secondary charged particles and microdosimetric basis of q-value for neutrons; personnel dosimetry; concepts for radiation protection; ambient monitoring; TEPC and ion chambers in radiation protection; beam dosimetry; track detectors (CR-39); dosimetry at biomedical irradiation facilities; health physics at therapy facilities; calibration for radiation protection; devices for beam dosimetry (TLD and miscellaneous); therapy and biomedical irradiation facilities; treatment planning. (HP)

[Laboratory accreditation and proficiency testing].

Science.gov (United States)

Kuwa, Katsuhiko

2003-05-01

ISO/TC 212 covering clinical laboratory testing and in vitro diagnostic test systems will issue the international standard for medical laboratory quality and competence requirements, ISO 15189. This standard is based on the ISO/IEC 17025, general requirements for competence of testing and calibration laboratories and ISO 9001, quality management systems-requirements. Clinical laboratory services are essential to patient care and therefore should be available to meet the needs of all patients and clinical personnel responsible for human health care. If a laboratory seeks accreditation, it should select an accreditation body that operates according to this international standard and in a manner which takes into account the particular requirements of clinical laboratories. Proficiency testing should be available to evaluate the calibration laboratories and reference measurement laboratories in clinical medicine. Reference measurement procedures should be of precise and the analytical principle of measurement applied should ensure reliability. We should be prepared to establish a quality management system and proficiency testing in clinical laboratories.

Personal dosimetry performance testing in the United States

International Nuclear Information System (INIS)

Soares, C.G.

2005-01-01

Full text: The basis for personal dosimetry performance testing in the United States is ANSI/HPS N13.11 (2002). Now in its third edition, this standard has been in place since 1983. Testing under this standard is administered by the National Voluntary Accreditation Program (NVLAP), and accreditation of dosimetry processors under this program is required by US Nuclear Regulatory Commission (NRC) regulations. The US Department of Energy (DOE) also maintains a testing program for its laboratories and contractors, administered by the Department of Energy Laboratory Accreditation Program (DOELAP). A focus in recent years has been the modification of ANSI/HPS N13.11 to allow acceptance by both testing programs in order to bring harmonization to US personal dosimeter processing testing. The testing philosophy of ANSI N13.11 has always combined elements of type testing and routine performance testing and is thus different from the testing philosophy used in the rest of the world. This unique philosophy is explored in detail in this presentation, along with trends in the development of the document to its present state. In addition, a look will be taken at what the future holds for the next revision of the document, scheduled to begin in 2005. (author)

Development and calibration of a routine dosimetry system for radiation processing

International Nuclear Information System (INIS)

Ferreira, Danilo Cardenuto

2013-01-01

The development and calibration of a routine dosimetry system based on commercial, low cost photodiode (SFH 206) are presented in this work. The dosimeter probe was designed to operate unbiased in the direct current mode. The radiations were performed with Cobalt-60 Panoramic Irradiator facility in the dose-rate range of 8.1 Gy/h - 125 Gy/h. The photocurrents generated in the device, in each dose-rate, were registered with a digital electrometer and stored during the exposure time. The current response of the diode was measured as a function of the time in steps from 1 Gy up to 200 Gy with accumulated dose up to 15 kGy. In this range, the dose-response of the diode, given by the charge as function of dose, was linear with correlation coefficient better than 0.998. These results were compared with those obtained using Gafchromic film dosimetry often used in routine. To monitor possible gamma radiation effects produced on the diode, the current and charge sensitivities were measured as a function of the absorbed dose. For doses up to 15 kGy, it was not observed any radiation damage what confirms the reproducibility of the diode response better than 3 %. Finally, due to the small experimental errors ( 5% ) and good spatial resolution of the diode it was possible to measure the transit dose due to the movement of the Cobalt-60 radioactive source as well the dose rate mapping in the Panoramic Irradiator. (author)

Clinical application of in vivo dosimetry for external telecobalt machine

International Nuclear Information System (INIS)

Mohammed, H. H. M.

2011-01-01

In external beam radiotherapy quality assurance is carried out on the individual components of treatment chain. The patient simulating device, planning system and treatment machine are tested regularly according to set protocols developed by national and international organizations. Even thought these individual systems are not tested for errors which can be made in the transfer between the systems. The best quality assurance for the treatment planning chain. In vivo dosimetry is used as a quality assurance tool for verifying dosimetry as either the entrance or exit surface of the patient undergoing external beam radiotherapy. It is a proven reliable method of checking overall treatment accuracy, allowing verification of dosimetry and dose calculation as well as patient treatment setup. Accurate in vivo dosimetry is carried out if diodes and thermoluminescence dosimeters (TLDs). the main detector types in use for in vivo dosimetry, are carefully calibrated and the factors influencing their sensitivity are taken into account. The aim of this study was to verify the response of TLDs type (LiF: Mg, Cu, p) use in radiotherapy, to establish calibration procedure for TLDs and to evaluate entrance dose obtained by the treatment planning system with measured dose using thermoluminescence detectors. Calibration of TLDs was done using Cobalt-60 teletherapy machine, linearity and calibration factors were determined. Measurements were performed in random phantom for breast irradiation (for the breast irradiation ( For the breast irradiation technique considered, wedge field was used). All TLDs were processed and analyzed at RICK. In vivo dosimetry represents a technique that has been widely employed to evaluate the dose to the patient mainly in radiotherapy. Thermoluminescent dosimeters are considered the gold stander for in vivo dosimetry and do not require cables for measurements which makes them ideal for mail based studies and have no dose rate or temperature dependence

Activities developed by the biological dosimetry laboratory of the Autoridad Regulatoria Nuclear - ARN of Argentina

International Nuclear Information System (INIS)

Radl, A.; Sapienza, C.E.; Taja, M.R.; Bubniak, R.; Deminge, M.; Di Giorgio, M.

2013-01-01

Biological dosimetry (DB) allows to estimate doses absorbed in individuals exposed to ionizing radiation through the quantification of stable and unstable chromosome aberrations (SCA and UCA). The frequency of these aberrations is referred to a calibration dose response curve (in vitro) to determine the doses of the individual to the whole body. The DB is a necessary support for programs of national radiation protection and response systems in nuclear or radiological emergencies in the event of accidental or incidental, single overexposure or large scale. In this context the Laboratory of Dosimetry Biological (LDB) of the Authority Regulatory Nuclear (ARN) Argentina develops and applies different dosimeters cytogenetic from four decades ago. These dosimeters provide a fact more within the whole of the information necessary for an accidental, complementing the physical and clinical dosimetry exposure assessment. The most widely used in the DB biodosimetric method is the quantification of SCA (dicentrics and rings Central) from a sample of venous blood. The LDB is accredited for the trial, under rules IRAM 301: 2005 (ISO / IEC 17025: 2005) and ISO 19238:2004. Test applies to the immediate dosimetry evaluation of acute exposures, all or a large part of the body in the range 0,1-5 Gy. In this context the LDB is part of the Latin American network of DB (LBDNet), BioDoseNet-who and response system in radiological emergencies and nuclear IAEA-RANET, being enabled to summon the LBDNet if necessary

Quality assurance in the measurement of internal radioactive contamination and dose assessment and the United States Department of Energy Laboratory Accreditation Program

International Nuclear Information System (INIS)

Bhatt, Anita

2016-01-01

The Quality Assurance for analytical measurement of internal radioactive contamination and dose assessment in the United States (US) is achieved through the US Department of Energy (DOE) Laboratory Accreditation Program (DOELAP) for both Dosimetry and Radio bioassay laboratories for approximately 150,000 radiation workers. This presentation will explain the link between Quality Assurance and the DOELAP Accreditation process. DOELAP is a DOE complex-wide safety program that ensures the quality of worker radiation protection programs. DOELAP tests the ability of laboratories to accurately measure and quantify radiation dose to workers and assures the laboratories quality systems are capable of defending and sustaining their measurement results. The United States Law in Title 10 of the Code of Federal Regulations 835 requires that personnel Dosimetry and Radio bioassay programs be tested and accredited

Third conference on radiation protection and dosimetry

International Nuclear Information System (INIS)

1991-01-01

This conference has been designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To partly fulfill these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection has been prepared. General topics include external dosimetry, internal dosimetry, instruments, regulations and standards, accreditation and test programs, research advances, and applied program experience. This publication provides a summary of the technical program and a collection of abstracts of the oral presentations

Calibration of semiconductors diodes for in vivo dosimetry in total body irradiation treatments; Calibracao de diodos semicondutores para dosimetria in vivo em tratamentos de irradiacao de corpo inteiro

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Fernanda F.; Costa, Alessandro M.; Ghilardi Netto, Thomaz, E-mail: ferretti.oliveira@gmail.com [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias e Letras. Departamento de Fisica; Amaral, Leonardo L. [Universidade de Sao Paulo (HCFMRP/USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas. Servico de Radioterapia

2012-08-15

This paper presents the results of in vivo dosimetry with p-type semiconductors diodes, EDP-15 (Scanditronix Wellhoefer) of two patients who underwent total body irradiation treatments, at Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto University of Sao Paulo (HCFMRP-USP). The diodes were well calibrated and the calibration factors were determined with the aid of a reference ionization chamber (FC065, IBA dosimetry, sensitive volume of 0.65 cm{sup 3}).The calibration was performed in a Total Body Irradiation (TBI) setup, using solid water phantoms. Different lateral thicknesses from one patient were simulated and then the calibration factors were determined by means of maximum depth dose readings (half of the lateral thickness). The response difference between diode readings and the prescribed dose for both treatments was below 4%. This difference is in agreement as recommended by International Commission on Radiation Units (ICRU), which is {+-}5%. (author)

Clinical dosimetry

International Nuclear Information System (INIS)

Rassow, J.

1973-01-01

The main point of this paper on clinical dosimetry which is to be understood here as application of physical dosimetry on accelerators in medical practice, is based on dosimetric methodics. Following an explanation of the dose parameters and description of the dose distribution important for clinical practice as well as geometric irradiation parameters, the significance of a series of physical parameters such as accelerator energy, surface energy of average stopping power etc. is dealt with in detail. Following a section on field homogenization with bremsstrahlung and electron radiation, details on dosimetry in clinical practice are given. Finally, a few problems of dosemeter or monitor calibration on accelerators are described. The explanations are supplemented by a series of diagrams and tables. (ORU/LH) [de

History of personal dosimetry performance testing in the United States

International Nuclear Information System (INIS)

Soares, C. G.

2007-01-01

The basis for personal dosimetry performance testing in the United States is ANSI/HPS N13.11 (2001). Now in its third edition, this standard has been in place since 1983. Testing under this standard is administered by the National Voluntary Accreditation Program (NVLAP), and accreditation of dosimetry processors under this program is required by US Nuclear Regulatory Commission (NRC) regulations. The US Dept. of Energy (DOE) also maintains a testing program for its laboratories and contractors, administered by the Dept. of Energy Laboratory Accreditation Program (DOELAP). A focus in recent years has been the modification of ANSI/HPS N13.11 to allow acceptance by both testing programs in order to bring harmonisation to US personal dosemeter processing testing. Since there is no type testing program in the US for personal dosemeters, the testing philosophy of ANSI N13.11 has always combined elements of type testing and routine performance testing. This philosophy is explored in detail in this presentation, along with trends in the development of the document to its present state. In addition, a look will be taken at what the future holds for the next revision of the document, scheduled to begin in 2005. (authors)

Dose levels of the occupational radiation exposures in Poland based on results from the accredited dosimetry service at the IFJ PAN, Krakow.

Science.gov (United States)

Budzanowski, Maciej; Kopeć, Renata; Obryk, Barbara; Olko, Paweł

2011-03-01

Individual dosimetry service based on thermoluminescence (TLD) detectors has started its activity at the Institute of Nuclear Physics (IFJ) in Krakow in 1965. In 2002, the new Laboratory of Individual and Environment Dosimetry (Polish acronym LADIS) was established and underwent the accreditation according to the EN-PN-ISO/IEC 17025 standard. Nowadays, the service is based on the worldwide known standard thermoluminescent detectors MTS-N (LiF:Mg,Ti) and MCP-N (LiF:Mg,Cu,P), developed at IFJ, processed in automatic thermoluminescent DOSACUS or RE2000 (Rados Oy, Finland) readers. Laboratory provides individual monitoring in terms of personal dose equivalent H(p)(10) and H(p)(0.07) in photon and neutron fields, over the range from 0.1 mSv to 1 Sv, and environmental dosimetry in terms of air kerma K(a) over the range from 30 μGy to 1 Gy and also ambient dose equivalent H*(10) over the range from 30 μSv to 1 Sv. Dosimetric service is currently performed for ca. 3200 institutions from Poland and abroad, monitored on quarterly and monthly basis. The goal of this paper is to identify the main activities leading to the highest radiation exposures in Poland. The paper presents the results of statistical evaluation of ∼ 100,000 quarterly H(p)(10) and K(a) measurements performed between 2002 and 2009. Sixty-five per cent up to 90 % of all individual doses in Poland are on the level of natural radiation background. The dose levels between 0.1 and 5 mSv per quarter are the most frequent in nuclear medicine, veterinary and industrial radiography sectors.

A Finnish national code of practice for reference dosimetry of radiation therapy

International Nuclear Information System (INIS)

Kosunen, A.; Sipilae, P.; Jaervinen, H.; Parkkinen, R.; Jokelainen, I.

2002-01-01

Full text: A national Code of Practice (CoP) for reference dosimetry of radiation therapy in Finland will be established during 2002 and will be implemented from the beginning of 2003. The CoP will cover dosimetry of the conventional radiotherapy modalities used in Finland i.e. external radiotherapy with megavoltage photon and electron beams, external radiotherapy with low energy kilovoltage X-ray beams and brachytherapy. The formalisms for external radiation beam dosimetry are those of TRS 389. For brachytherapy the formalism will follow the general guidelines of TECDOC-1274. The CoP will be prepared by the SSDL of STUK in close co-operation with the Finnish radiotherapy physicists. For external beam radiotherapy, the main objective of the national Code of Practice for radiation therapy dosimetry is to maintain the achieved good level of consistency of the dosimetry procedures in external beam radiotherapy as the 'absorbed dose to water' based approach of TRS 389 is implemented in Finland. In the CoP the dosimetry the procedures are described for the whole dosimetry chain starting from the calibration of the ionisation chambers at the SSDL of STUK and ending to the calibration of the beam monitor ionisation chamber of a linear accelerator. For brachytherapy dosimetry the aim is to fix the national practice for reference air kerma rate calibrations both for radioactive sources and for well-type ionisation chambers. Although the dosimetry procedures are described independently of the SSDL service, CoP makes use of the special features of the calibration service offered by the SSDL of STUK. For ionisation chambers used for photon dosimetry the calibration factors for the user measurement chain are given not only for the actual reference beam quality ( 60 Co) but also for a set of user beam qualities. Furthermore, SSDL of STUK offers calibration services for plane parallel ionisation chambers in an electron beam of a user linac. For brachytherapy SSDL of STUK has

Performance of dichromate dosimetry systems in calibration and dose intercomparison

International Nuclear Information System (INIS)

Bof, E.S.; Smolko, E.

1999-01-01

This report presents the results of the High Dose Dosimetry Laboratory of Argentina during ten years of international intercomparisons for high dose with the International Dose Assurance Service (IDAS) of the IAEA, using the standard high dose dichromate dosimetry system, and the results of a high dose intercomparison regional exercise in which our Laboratory acted as a reference laboratory, using the standard high dose and low dose dichromate dosimetry system. (author)

Quality management system in the CIEMAT Radiation Dosimetry Service.

Science.gov (United States)

Martín, R; Navarro, T; Romero, A M; López, M A

2011-03-01

This paper describes the activities realised by the CIEMAT Radiation Dosimetry Service (SDR) for the implementation of a quality management system (QMS) in order to achieve compliance with the requirements of ISO/IEC 17025 and to apply for the accreditation for testing measurements of radiation dose. SDR has decided the accreditation of the service as a whole and not for each of its component laboratories. This makes it necessary to design a QMS common to all, thus ensuring alignment and compliance with standard requirements, and simplifying routine works as possible.

A new method for dosimetry with films radiochromic

International Nuclear Information System (INIS)

Mendez Carot, I.

2013-01-01

in this paper a new method is presented and the results of the comparison between the calibration is summarized based on a planning reference and calibration obtained from the irradiated fragments measure different dose levels multichannel compare dosimetry based on the weighted average dosimetry described by Micke et al.(present in the FilmQAPro software) and, finally, show different results obtained with the method proposed in several applications clinics. (Author)

Situation analysis of occupational and environmental health laboratory accreditation in Thailand.

Science.gov (United States)

Sithisarankul, Pornchai; Santiyanont, Rachana; Wongpinairat, Chongdee; Silva, Panadda; Rojanajirapa, Pinnapa; Wangwongwatana, Supat; Srinetr, Vithet; Sriratanaban, Jiruth; Chuntutanon, Swanya

2002-06-01

The objective of this study was to analyze the current situation of laboratory accreditation (LA) in Thailand, especially on occupational and environmental health. The study integrated both quantitative and qualitative approaches. The response rate of the quantitative questionnaires was 54.5% (226/415). The majority of the responders was environmental laboratories located outside hospital and did not have proficiency testing. The majority used ISO 9000, ISO/IEC 17025 or ISO/ EEC Guide 25, and hospital accreditation (HA) as their quality system. However, only 30 laboratories were currently accredited by one of these systems. Qualitative research revealed that international standard for laboratory accreditation for both testing laboratory and calibration laboratory was ISO/IEC Guide 25, which has been currently revised to be ISO/IEC 17025. The National Accreditation Council (NAC) has authorized 2 organizations as Accreditation Bodies (ABs) for LA: Thai Industrial Standards Institute, Ministry of Industry, and Bureau of Laboratory Quality Standards, Department of Medical Sciences, Ministry of Public Health. Regarding LA in HA, HA considered clinical laboratory as only 1 of 31 items for accreditation. Obtaining HA might satisfy the hospital director and his management team, and hence might actually be one of the obstacles for the hospital to further improve their laboratory quality system and apply for ISO/IEC 17025 which was more technically oriented. On the other hand, HA may be viewed as a good start or even a pre-requisite for laboratories in the hospitals to further improve their quality towards ISO/IEC 17025. Interviewing the director of NAC and some key men in some large laboratories revealed several major problems of Thailand's LA. Both Thai Industrial Standards Institute and Bureau of Laboratory Quality Standards did not yet obtain Mutual Recognition Agreement (MRA) with other international ABs. Several governmental bodies had their own standards and

A new form of the calibration curve in radiochromic dosimetry. Properties and results

International Nuclear Information System (INIS)

Tamponi, Matteo; Bona, Rossana; Poggiu, Angela; Marini, Piergiorgio

2016-01-01

Purpose: This work describes a new form of the calibration curve for radiochromic dosimetry that depends on one fit parameter. Some results are reported to show that the new curve performs as well as those previously used and, more importantly, significantly reduces the dependence on the lot of films, the film orientation on the scanner, and the time after exposure. Methods: The form of the response curve makes use of the net optical densities ratio against the dose and has been studied by means of the Beer–Lambert law and a simple modeling of the film. The new calibration curve has been applied to EBT3 films exposed at 6 and 15 MV energy beams of linear accelerators and read-out in transmission mode by means of a flatbed color scanner. Its performance has been compared to that of two established forms of the calibration curve, which use the optical density and the net optical density against the dose. Four series of measurements with four lots of EBT3 films were used to evaluate the precision, accuracy, and dependence on the time after exposure, orientation on the scanner and lot of films. Results: The new calibration curve is roughly subject to the same dose uncertainty, about 2% (1 standard deviation), and has the same accuracy, about 1.5% (dose values between 50 and 450 cGy), as the other calibration curves when films of the same lot are used. Moreover, the new calibration curve, albeit obtained from only one lot of film, shows a good agreement with experimental data from all other lots of EBT3 films used, with an accuracy of about 2% and a relative dose precision of 2.4% (1 standard deviation). The agreement also holds for changes of the film orientation and of the time after exposure. Conclusions: The dose accuracy of this new form of the calibration curve is always equal to or better than those obtained from the two types of curves previously used. The use of the net optical densities ratio considerably reduces the dependence on the lot of films, the

A new form of the calibration curve in radiochromic dosimetry. Properties and results

Energy Technology Data Exchange (ETDEWEB)

Tamponi, Matteo, E-mail: mtamponi@aslsassari.it; Bona, Rossana; Poggiu, Angela; Marini, Piergiorgio [Medical Physics Unit, ASL Sassari, Via Enrico de Nicola, Sassari 07100 (Italy)

2016-07-15

Purpose: This work describes a new form of the calibration curve for radiochromic dosimetry that depends on one fit parameter. Some results are reported to show that the new curve performs as well as those previously used and, more importantly, significantly reduces the dependence on the lot of films, the film orientation on the scanner, and the time after exposure. Methods: The form of the response curve makes use of the net optical densities ratio against the dose and has been studied by means of the Beer–Lambert law and a simple modeling of the film. The new calibration curve has been applied to EBT3 films exposed at 6 and 15 MV energy beams of linear accelerators and read-out in transmission mode by means of a flatbed color scanner. Its performance has been compared to that of two established forms of the calibration curve, which use the optical density and the net optical density against the dose. Four series of measurements with four lots of EBT3 films were used to evaluate the precision, accuracy, and dependence on the time after exposure, orientation on the scanner and lot of films. Results: The new calibration curve is roughly subject to the same dose uncertainty, about 2% (1 standard deviation), and has the same accuracy, about 1.5% (dose values between 50 and 450 cGy), as the other calibration curves when films of the same lot are used. Moreover, the new calibration curve, albeit obtained from only one lot of film, shows a good agreement with experimental data from all other lots of EBT3 films used, with an accuracy of about 2% and a relative dose precision of 2.4% (1 standard deviation). The agreement also holds for changes of the film orientation and of the time after exposure. Conclusions: The dose accuracy of this new form of the calibration curve is always equal to or better than those obtained from the two types of curves previously used. The use of the net optical densities ratio considerably reduces the dependence on the lot of films, the

Assembly of a laboratory for calibration in brachytherapy. Comparison of responses with different instrumentation

International Nuclear Information System (INIS)

Pirchio, R.; Saravi, M.

2006-01-01

A common practice in quality control programs for dosimetry in brachytherapy is the source calibration. The AAPM (American Association of Physicists in Medicine) in the Task Group No. 40 (TG-40) it recommends that each institution that offers a brachytherapy service verifies the intensity of each source provided by the maker with secondary traceability. For such a reason it is necessary to have laboratories able to make calibrations of sources, traceable electrometer-chambers to primary or credited laboratories. The Regional Center of Reference of Dosimetry of the CNEA (National Commission of Atomic Energy) it is in the stage of finalization of the assembly of a Laboratory for source calibration and use equipment in brachytherapy. For it has two ionization chambers well type and two electrometers gauged by the Accredited Dosimetry Calibration Laboratory of the University of Wisconsin. Also account with a wide variety of supports and with a tube of 137 Cs pattern 3M model 6500/6D6C. The procedures for the calibration of sources and equipment were elaborated starting from the TECDOC-1274. On the other hand, its were carried out measurements with different instrumentation for the comparison of responses and at the same time to implement the calibration procedures. For it, its were used chambers and electrometers of the institution, of hospitals and of the national company 'Solydes'. In the measurements its were used seeds of 125 I taken place in Argentina and the tube of 137 Cs pattern mentioned previously. In first place it was proceeded to the determination of the center of the region of the plateau in the axial response for the seeds of Iodine-125 and the tube of Cesium-137 pattern using different chambers. Later on its were carried out measurements of accumulated loads during a certain interval of time in this position. The calibration factors of each chamber were determined, N Sk (μGy m 2 h -1 A -1 ), as the quotient of the kerma rate in reference air of the

Quality control through dosimetry at a contract radiation processing facility

International Nuclear Information System (INIS)

Du Plessis, T.A.; Roediger, A.H.A.

1985-01-01

Reliable dosimetry procedures constitute a very important part of process control and quality assurance at a contract gamma radiation processing facility that caters for a large variety of different radiation applications. The choice, calibration and routine intercalibration of the dosimetry systems employed form the basis of a sound dosimetry policy in radiation processing. With the dosimetric procedures established, detailed dosimetric mapping of the irradiator upon commissioning (and whenever source modifications take place) is carried out to determine the radiation processing characteristics and peformance of the plant. Having established the irradiator parameters, routine dosimetry procedures, being part of the overall quality control measures, are employed. In addition to routine dosimetry, independent monitoring of routine dosimetry is performed on a bi-monthly basis and the results indicate a variation of better than 3%. On an annaul basis the dosimetry systems are intercalibrated through at least one primary standard dosimetry laboratory and to date a variation of better than 5% has been experienced. The company also participates in the Pilot Dose Assurance Service of the International Atomic Energy Agency, using the alanine/ESR dosimetry system. Routine calibration of the instrumentation employed is carried out on a regular basis. Detailed permanent records are compiled on all dosimetric and instrumentation calibrations, and the routine dosimetry employed at the plant. Certificates indicating the measured absorbed radiation doses are issued on request and in many cases are used for the dosimetric release of sterilized medical and pharmaceutical products. These procedures, used by Iso-Ster at its industrial gamma radiation facility, as well as the experience built up over a number of years using radiation dosimetry for process control and quality assurance are discussed. (author)

EPR of gamma irradiated solid sucrose and UV spectra of its solution. An attempt for calibration of solid state/EPR dosimetry

International Nuclear Information System (INIS)

Yordanov, N.D.; Karakirova, Y.

2007-01-01

A simple new approach for independent calibration of solid state/EPR (SS/EPR) dosimetry system is reported. It is based on the fact that: (i) gamma-irradiation of solid sucrose (sugar) induces stable EPR detectable free radicals accompanied by UV detectable brown colour stable in the solid state and in solution; (ii) both the EPR intensity of gamma-irradiated solid sucrose and its solution UV absorbance linearly depend on the absorbed dose high energy radiation and may be independently used for dosimetric purpose; (iii) UV spectrometers are calibrated. The correlation between EPR response and absorbed dose radiation of solid sucrose and UV absorption of its solutions is used in the present communication for calibration purpose. The procedure of sucrose extraction from sucrose-paraffin dosimeters is described. The calibration procedure may be applied to any other (alanine, self-calibrated, etc.) SS/EPR dosimeters, simultaneously irradiated with sucrose

Inter-Laboratory Comparison for Calibration of Relative Humidity Devices Among Accredited Laboratories in Malaysia

Science.gov (United States)

Hussain, F.; Khairuddin, S.; Othman, H.

2017-01-01

An inter-laboratory comparison in relative humidity measurements among accredited laboratories has been coordinated by the National Metrology Institute of Malaysia. It was carried out to determine the performance of the participating laboratories. The objective of the comparison was to acknowledge the participating laboratories competencies and to verify the level of accuracies declared in their scope of accreditation, in accordance with the MS ISO/IEC 17025 accreditation. The measurement parameter involved was relative humidity for the range of 30-90 %rh at a nominal temperature of 50°C. Eight accredited laboratories participated in the inter-laboratory comparison. Two units of artifacts have been circulated among the participants as the transfer standards.

Hanford External Dosimetry Program

International Nuclear Information System (INIS)

Fix, J.J.

1990-10-01

This document describes the Hanford External Dosimetry Program as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy (DOE) and its Hanford contractors. Program services include administrating the Hanford personnel dosimeter processing program and ensuring that the related dosimeter data accurately reflect occupational dose received by Hanford personnel or visitors. Specific chapters of this report deal with the following subjects: personnel dosimetry organizations at Hanford and the associated DOE and contractor exposure guidelines; types, characteristics, and procurement of personnel dosimeters used at Hanford; personnel dosimeter identification, acceptance testing, accountability, and exchange; dosimeter processing and data recording practices; standard sources, calibration factors, and calibration processes (including algorithms) used for calibrating Hanford personnel dosimeters; system operating parameters required for assurance of dosimeter processing quality control; special dose evaluation methods applied for individuals under abnormal circumstances (i.e., lost results, etc.); and methods for evaluating personnel doses from nuclear accidents. 1 ref., 14 figs., 5 tabs

Advances in reference and transfer dosimetry

Energy Technology Data Exchange (ETDEWEB)

Desrosiers, M.F. [Ionizing Radiation Division, Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

1999-07-01

All prerequisites are now in place to create a fundamentally and radically different type of calibration service for the radiation processing industry. Advancements in dosimetry and information technology can be combined to provide industry with on-line calibrations, on demand at a low cost. The remote calibration service will serve as a basis for other areas of metrology. (Author)

Advances in reference and transfer dosimetry

International Nuclear Information System (INIS)

Desrosiers, M.F.

1999-01-01

All prerequisites are now in place to create a fundamentally and radically different type of calibration service for the radiation processing industry. Advancements in dosimetry and information technology can be combined to provide industry with on-line calibrations, on demand at a low cost. The remote calibration service will serve as a basis for other areas of metrology. (Author)

ESR/Alanine {gamma}-dosimetry in the 10-30 Gy range

Energy Technology Data Exchange (ETDEWEB)

Fainstein, C. E-mail: cfainstein@cab.cnea.gov.ar; Winkler, E.; Saravi, M

2000-05-15

We report Alanine Dosimeter preparation, procedures for using the ESR/Dosimetry method, and the resulting calibration curve for {gamma}-irradiation in the range from 10-30 Gy. We use calibration curve to measure the irradiation dose in {gamma}-irradiation of human blood, as required in Blood Transfusion Therapy. The ESR/Alanine results are compared against those obtained using the thermoluminescent dosimetry (TLD) method.

Software for evaluation of EPR-dosimetry performance

International Nuclear Information System (INIS)

Shishkina, E.A.; Timofeev, Yu.S.; Ivanov, D.V.

2014-01-01

Electron paramagnetic resonance (EPR) with tooth enamel is a method extensively used for retrospective external dosimetry. Different research groups apply different equipment, sample preparation procedures and spectrum processing algorithms for EPR dosimetry. A uniform algorithm for description and comparison of performances was designed and implemented in a new computer code. The aim of the paper is to introduce the new software 'EPR-dosimetry performance'. The computer code is a user-friendly tool for providing a full description of method-specific capabilities of EPR tooth dosimetry, from metrological characteristics to practical limitations in applications. The software designed for scientists and engineers has several applications, including support of method calibration by evaluation of calibration parameters, evaluation of critical value and detection limit for registration of radiation-induced signal amplitude, estimation of critical value and detection limit for dose evaluation, estimation of minimal detectable value for anthropogenic dose assessment and description of method uncertainty. (authors)

Air kerma standard for calibration of well-type chambers in Brazil using {sup 192}Ir HDR sources and its traceability

Energy Technology Data Exchange (ETDEWEB)

Di Prinzio, Renato; Almeida, Carlos Eduardo de [Laboratorio de Ciencias Radiologicas-Universidade do Estado do Rio de Janeiro (LCR/UERJ), R. Sao Francisco Xavier, 524, Pavilhao Haroldo Lisboa da Cunha, Terreo, Sala 136-Maracana, CEP 20550-900-Rio de Janeiro/RJ-Rio de Janeiro, RJ (Brazil) and Instituto de Radioprotecao e Dosimetria-Comissao Nacional de Energia Nuclear (IRD/CNEN), Av. Salvador Allende, s/n, Jacarepagua-CE22780-160-Rio de Janeiro, RJ (Brazil); Laboratorio de Ciencias Radiologicas-Universidade do Estado do Rio de Janeiro (LCR/UERJ), R. Sao Francisco Xavier, 524, Pavilhao Haroldo Lisboa da Cunha, Terreo, Sala 136-Maracana, CEP 20550-900-Rio de Janeiro/RJ-Rio de Janeiro, RJ (Brazil)

2009-03-15

In Brazil there are over 100 high dose rate (HDR) brachytherapy facilities using well-type chambers for the determination of the air kerma rate of {sup 192}Ir sources. This paper presents the methodology developed and extensively tested by the Laboratorio de Ciencias Radiologicas (LCR) and presently in use to calibrate those types of chambers. The system was initially used to calibrate six well-type chambers of brachytherapy services, and the maximum deviation of only 1.0% was observed between the calibration coefficients obtained and the ones in the calibration certificate provided by the UWADCL. In addition to its traceability to the Brazilian National Standards, the whole system was taken to University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) for a direct comparison and the same formalism to calculate the air kerma was used. The comparison results between the two laboratories show an agreement of 0.9% for the calibration coefficients. Three Brazilian well-type chambers were calibrated at the UWADCL, and by LCR, in Brazil, using the developed system and a clinical HDR machine. The results of the calibration of three well chambers have shown an agreement better than 1.0%. Uncertainty analyses involving the measurements made both at the UWADCL and LCR laboratories are discussed.

FLEXIBLE SCOPE IN ACCREDITATION - INTRODUCING VAGUENESS OR BETTER EXPRESSION OF SCOPE

Directory of Open Access Journals (Sweden)

Miloš Jelić

2007-09-01

Full Text Available Historically, laboratory accreditation has been grounded on fixed scope of accreditation to establish precisely and unambiguously the range of tests and calibrations covered by a granted accreditation. By the time elapsed it was noticed that such approach sometimes appears to be restrictive since it constrains new or modified methods to be added to a laboratory's scope, even where competence in this general area has already been demonstrated. Accreditation of a flexible scope places more of the responsibility onto the laboratory itself because it imposes to the laboratory to establish and maintain management system that can control its proposed approach. Flexible scope of accreditation yields benefit to all accreditation stakeholders but, on the other hand, introduces more requiring interpretations of relevant standard clauses and includes the bounds of the scope which are defined in more distinct way.

Implementation of ISO 28218 quality system in the laboratory of body radioactivity counter CIEMAT; Implementacion de la norma ISO 28218 en el sistema de calidad del laboratorio del contador de radiactividad corporal del CIEMAT

Energy Technology Data Exchange (ETDEWEB)

Navarro Amaro, J. F.; Perez Lopez, B.; Lopez Ponte, M. A.; Perez Jimenez, C.

2011-07-01

The laboratory of body radioactivity counter has implemented IS0 28218 standard Performance Criteria for Radio bioassay in all measured in vivo techniques of internal contamination in the human organism in monitoring programs defined by the Personal Dosimetry Service Internal CIEMAT. The application of this rule in the laboratory's quality system is essential to meet the technical requirements of the standard IS0/IEC 17025 with the purpose of obtaining ENAC accreditation as a testing laboratory and calibration within the framework of the accreditation of Service CIEMAT Radiation Dosimetry. (Author)

Implementation of ISO 28218 quality system in the laboratory of body radioactivity counter CIEMAT

International Nuclear Information System (INIS)

Navarro Amaro, J. F.; Perez Lopez, B.; Lopez Ponte, M. A.; Perez Jimenez, C.

2011-01-01

The laboratory of body radioactivity counter has implemented IS0 28218 standard Performance Criteria for Radio bioassay in all measured in vivo techniques of internal contamination in the human organism in monitoring programs defined by the Personal Dosimetry Service Internal CIEMAT. The application of this rule in the laboratory's quality system is essential to meet the technical requirements of the standard IS0/IEC 17025 with the purpose of obtaining ENAC accreditation as a testing laboratory and calibration within the framework of the accreditation of Service CIEMAT Radiation Dosimetry. (Author)

Measurement uncertainty. A practical guide for Secondary Standards Dosimetry Laboratories

International Nuclear Information System (INIS)

2008-05-01

The need for international traceability for radiation dose measurements has been understood since the early nineteen-sixties. The benefits of high dosimetric accuracy were recognized, particularly in radiotherapy, where the outcome of treatments is dependent on the radiation dose delivered to patients. When considering radiation protection dosimetry, the uncertainty may be greater than for therapy, but proper traceability of the measurements is no less important. To ensure harmonization and consistency in radiation measurements, the International Atomic Energy Agency (IAEA) and the World Health Organization (WHO) created a Network of Secondary Standards Dosimetry Laboratories (SSDLs) in 1976. An SSDL is a laboratory that has been designated by the competent national authorities to undertake the duty of providing the necessary link in the traceability chain of radiation dosimetry to the international measurement system (SI, for Systeme International) for radiation metrology users. The role of the SSDLs is crucial in providing traceable calibrations; they disseminate calibrations at specific radiation qualities appropriate for the use of radiation measuring instruments. Historically, although the first SSDLs were established mainly to provide radiotherapy level calibrations, the scope of their work has expanded over the years. Today, many SSDLs provide traceability for radiation protection measurements and diagnostic radiology in addition to radiotherapy. Some SSDLs, with the appropriate facilities and expertise, also conduct quality audits of the clinical use of the calibrated dosimeters - for example, by providing postal dosimeters for dose comparisons for medical institutions or on-site dosimetry audits with an ion chamber and other appropriate equipment. The requirements for traceable and reliable calibrations are becoming more important. For example, for international trade where radiation products are manufactured within strict quality control systems, it is

Calibration of SSTR neutron dosimetry for TMI-2 applications

International Nuclear Information System (INIS)

Gold, R.; Ruddy, F.H.; Roberts, J.H.; Preston, C.C.; Ulseth, J.A.; McElroy, W.N.; Leitz, F.J.; Hayward, B.R.; Schmittroth, F.A.

1982-01-01

Application of neutron dosimetry for assessment of fuel distribution throughout the Three Mile Island-2 (TMI-2) reactor-core region and the primary-coolant system is advanced. Neutron dosimetry in the reactor cavity, i.e. the cavity between the pressure vessel and the biological shield, could provide data for the assessment of the core fuel distribution. A more immediate task entails locating and quantifying the amount of fuel debris in the ex-core primary coolant system; in the range of 1 to 1000 kg. Solid-state track-recorder (SSTR) neutron dosimetry is considered for such exploratory scoping experiments at TMI-2. The sensitivity of mica- 235 U (asymptotically thick) SSTR has been ascertained for such environments. It has been demonstrated that the SSTR method has adequate sensitivity to properly respond and detect fuel quantities of the order of 1 kg in the ex-core primary coolant system. 21 figures

Accuracy Requirements in Medical Radiation Dosimetry

International Nuclear Information System (INIS)

Andreo, P.

2011-01-01

The need for adopting unambiguous terminology on 'accuracy in medical radiation dosimetry' which is consistent with international recommendations for metrology is emphasized. Uncertainties attainable, or the need for improving their estimates, are analysed for the fields of radiotherapy, diagnostic radiology and nuclear medicine dosimetry. This review centres on uncertainties related to the first step of the dosimetry chain in the three fields, which in all cases involves the use of a detector calibrated by a standards laboratory to determine absorbed dose, air kerma or activity under reference conditions in a clinical environment. (author)

Dosimetry in radiotherapy. V.1

International Nuclear Information System (INIS)

1988-01-01

A series of symposia on dosimetry in medicine and biology have been held by the IAEA in co-operation with WHO. The present symposium was the first one focusing on ''Dosimetry in Radiotherapy''. The papers presented reflected the different steps in the calibration chain such as the calibration standards established by the National Standards Laboratories and the conversion of the reading of calibrated instruments to the desired quantity, i.e. absorbed dose to water at a reference point in the user's beam at the radiotherapy clinic. The programme further examined the procedures necessary for optimization of the treatment of the patient, such as treatment planning methods, dose distribution studies, new techniques of dose measurement, improvements in the physical dose distributions/conformation therapy and special problems involved in total body treatments. Results of quality assurance in radiotherapy were presented from local hospitals as well as from national and international studies. Refs, figs and tabs

Standards in radiation protection at the IAEA Dosimetry Laboratory

International Nuclear Information System (INIS)

Czap, L.; Pernicka, F.; Matscheko, G.; Andreo, P.

1999-01-01

Approximately 90% of the Secondary Standard Dosimetry Laboratories (SSDLs) provide users with calibrations of radiation protection instruments, and the Agency is making every necessary effort to insure that SSDLs measurements in radiation protection are traceable to Primary Standards. The IAEA provides traceable calibrations of ionization chambers in terms of air kerma at radiation protection levels and ambient dose equivalent calibrations. SSDLs are encouraged to use the calibrations available from the Agency to provide traceability for their radiation protection measurements. Measurements on diagnostic X ray generators have become increasingly important in radiation protection and some SSDLs are involved in such measurements. The IAEA has proper radiation sources available to provide traceable calibrations to the SSDLs in this field, including an X ray unit specifically for mammography dedicated to standardization procedures. The different photon beam qualities and calibration procedures available in the Agency's Dosimetry Laboratory will be described. (author)

Report of a consultants meeting on dosimetry in diagnostic radiology

International Nuclear Information System (INIS)

Pernicka, F.

1999-01-01

During its biennial meeting in 1996, the Standing Advisory Committee 'SSDL Scientific Committee', recommended extending the long experience of the Agency in the field of standardization and monitoring dosimetry calibrations at radiotherapy and radiation protection level for the Secondary Standard Dosimetry Laboratory (SSDL) Network, to the field of diagnostic x-ray dosimetry. It was emphasized that 'Measurements on diagnostic x-ray machines have become increasingly important and some SSDLs are involved in such measurements. The Agency's dosimetry laboratory should, therefore, have proper radiation sources available to provide traceable calibrations to the SSDLs'. The purpose of the consultants' meeting was to advise the Agency on dosimetry in diagnostic radiology. They were specifically requested to overview scientific achievements in the field and to give advice to the Agency on the need for further developments. The purpose of the consultants' meeting was to advise the Agency on dosimetry in diagnostic radiology. They were specifically requested to overview scientific achievements in the field and to give advice to the Agency on the need for further developments

Dosimetry quality assurance in Martin Marietta Energy Systems' centralized external dosimetry system

International Nuclear Information System (INIS)

Souleyrette, M.L.

1992-01-01

External dosimetry needs at the four Martin Marietta Energy Systems facilities are served by Energy Systems Centralized External Dosimetry System (CEDS). The CEDS is a four plant program with four dosimeter distribution centers and two dosimeter processing centers. Each plant has its own distribution center, while processing centers are located at ORNL and the Y-12 Plant. The program has been granted accreditation by the Department of Energy Laboratory Accreditation Program (DOELAP). The CEDS is a TLD based system which is responsible for whole-body beta-gamma, neutron, and extremity monitoring. Beta-gamma monitoring is performed using the Harshaw/Solon Technologies model 8805 dosimeter. Effective October 1, 1992 the standard silver mylar has been replaced with an Avery mylar foil blackened on the underside with ink. This was done in an effort to reduce the number of light induced suspect readings. At this time we have little operational experience with the new blackened mylars-The CEDS neutron dosimeter is the Harshaw model 8806B. This card/holder configuration contains two TLD-600/TLD-700 chip pairs; one pair is located beneath a cadmium filter and one pair is located beneath a plastic filter. In routine personnel monitoring the CEDS neutron dosimeter is always paired with a CEDS beta-gamma dosimeter.The CEDS extremity dosimeter is composed of a Harshaw thin TLD-700 dosiclip placed inside a Teledyne RB-4 finger sachet. The finger sachet provides approximately 7 mg/cm 2 filtration over the chip. A teflon ring surrounds the dosiclip to help prevent tearing of the vinyl sachet

In vivo dosimetry with silicon diodes in total body irradiation

International Nuclear Information System (INIS)

Oliveira, F.F.; Amaral, L.L.; Costa, A.M.; Netto, T.G.

2014-01-01

The aim of this work is the characterization and application of silicon diode detectors for in vivo dosimetry in total body irradiation (TBI) treatments. It was evaluated the diode response with temperature, dose rate, gantry angulations and field size. A maximum response variation of 2.2% was obtained for temperature dependence. The response variation for dose rate and angular was within 1.2%. For field size dependence, the detector response increased with field until reach a saturation region, where no more primary radiation beam contributes for dose. The calibration was performed in a TBI setup. Different lateral thicknesses from one patient were simulated and then the calibration factors were determined by means of maximum depth dose readings. Subsequent to calibration, in vivo dosimetry measurements were performed. The response difference between diode readings and the prescribed dose for all treatments was below 4%. This difference is in agreement as recommended by the International Commission on Radiation Units and Measurements (ICRU), which is ±5%. The present work to test the applicability of a silicon diode dosimetry system for performing in vivo dose measurements in TBI techniques presented good results. These measurements demonstrated the value of diode dosimetry as a treatment verification method and its applicability as a part of a quality assurance program in TBI treatments. - Highlights: ► Characterization of a silicon diode dosimetry system. ► Application of the diodes for in vivo dosimetry in total body irradiation treatments. ► Implementation of in vivo dosimetry as a part of a quality assurance program in radiotherapy

Services of the CDRH X-ray calibration laboratory and their traceability to National Standards

Energy Technology Data Exchange (ETDEWEB)

Cerra, F.; Heaton, H.T. [Center for Devices and Radiological Health, Rockville, MD (United States)

1993-12-31

The X-ray Calibration Laboratory (XCL) of the Center for Devices and Radiological Health (CDRH) provides calibration services for the Food and Drug Administration (FDA). The instruments calibrated are used by FDA and contract state inspectors to verify compliance with federal x-ray performance standards and for national surveys of x-ray trends. In order to provide traceability of measurements, the CDRH XCL is accredited by the National Voluntary Laboratory Accreditation Program (NVLAP) for reference, diagnostic, and x-ray survey instrument calibrations. In addition to these accredited services, the CDRH XCL also calibrates non-invasive kVp meters in single- and three-phase x-ray beams, and thermoluminescent dosimeter (TLD) chips used to measure CT beam profiles. The poster illustrates these services and shows the traceability links back to the National Standards.

Services of the CDRH X-ray calibration laboratory and their traceability to National Standards

International Nuclear Information System (INIS)

Cerra, F.; Heaton, H.T.

1993-01-01

The X-ray Calibration Laboratory (XCL) of the Center for Devices and Radiological Health (CDRH) provides calibration services for the Food and Drug Administration (FDA). The instruments calibrated are used by FDA and contract state inspectors to verify compliance with federal x-ray performance standards and for national surveys of x-ray trends. In order to provide traceability of measurements, the CDRH XCL is accredited by the National Voluntary Laboratory Accreditation Program (NVLAP) for reference, diagnostic, and x-ray survey instrument calibrations. In addition to these accredited services, the CDRH XCL also calibrates non-invasive kVp meters in single- and three-phase x-ray beams, and thermoluminescent dosimeter (TLD) chips used to measure CT beam profiles. The poster illustrates these services and shows the traceability links back to the National Standards

Department of Energy standard for the performance testing of personnel dosimetry systems

International Nuclear Information System (INIS)

1986-12-01

This standard is intended to be used in the Department of Energy Laboratory Accreditation Program (DOELAP) for personnel dosimetry systems. It is based on the American National Standards Institute's (ANSI) ''Criteria for Testing Personnel Dosimetry Performance,'' ANSI N13.11-1983, recommendations made to DOE in ''Guidelines for the Calibration of Personnel Dosimeters,'' Pacific Northwest Laboratory (PNL)-4515 and comments received during peer review by DOE and DOE contractor personnel. The recommendations contained in PNL-4515 were based on an evaluation of ANSI N13.11 conducted for the Office of Nuclear Safety, DOE, by PNL. Parts of ANSI N13.11 that did not require modification were used essentially intact in this standard to maintain consistency with nationally recognized standards. Modifications to this standard have resulted from several DOE/DOE contractor reviews and a pilot testing session. An initial peer review by selected DOE and DOE contractor representatives on technical content was conducted in 1983. A review by DOE field offices, program offices, and contractors was conducted in mid-1984. A pilot performance testing session sponsored by the Office of Nuclear Safety was conducted in early 1985 by the Radiological and Environmental Sciences Laboratory, Idaho Falls. Results of the pilot test were reviewed in late 1985 by a DOE and DOE contractor committee. 11 refs., 4 tabs

Current NRC activities related to MQA

Energy Technology Data Exchange (ETDEWEB)

Trottier, C.A.; Nellis, D.O. [Nuclear Regulatory Commission, Washington, DC (United States)

1993-12-31

The U.S. Nuclear Regulatory Commission`s (NRC`s) interest in measurement quality assurance (MQA) goes back to before 1963, when the Atomic Energy Commission (AEC) published a notice in the Federal Register concerning the need for establishing a Film Dosimetry Calibration Laboratory, and also provided a set of minimum performance criteria to be used by the laboratory in evaluating film dosimetry services used by licensees. The proposed laboratory was not established, but in 1967 the AEC contracted with Battelle`s Pacific Northwest Laboratory (PNL) to evaluate film dosimeter performance criteria and provide a basis for establishing a Film Dosimetry Calibration Laboratory if the study showed that it was needed. Then, in 1973, the Conference of Radiation Control Program Directors (CRCPD), concerned with the state of dosimetry processing and the lack of adequate standards, recommended that the National Bureau of Standards (NBS) direct a performance testing program for personnel dosimetry processing services. Later, in 1976, NRC asked PNL to conduct a study to evaluate the four existing performance standards for personnel dosimetry processing. One result of this study was that the HPSSC standard, which later became ANSI N13.11, was recommended as the standard for use in a national dosimetry processing program. The rest is common knowledge. With the support of numerous other federal agencies and the CRCPD, NRC published a regulation, effective in 1988, that required all processors of personnel dosimeters be accredited under the National Voluntary Laboratory Accreditation Program (NVLAP), operated by the NBS, which is now called the National Institute of Standards and Technology (NIST). At present, there are 75 dosimetry processing laboratories accredited under NVLAP. NRC has also been involved in extremity dosimeters, health physics survey instruments, bioassay measurements, electronic personnel dosimeters, and environmental monitoring around nuclear power plants.

Radiation dosimetry and standards at the austrian dosimetry laboratory

International Nuclear Information System (INIS)

Leitner, A.

1984-10-01

The Austrian Dosimetry Laboratory, established and operated in cooperation between the Austrian Research Center Seibersdorf and the Federal Office of Metrology and Surveying (Bundesamt and Eich- und Vermessungswesen) maintains the national primary standards for radiation dosimetry. Furthermore its tasks include routine calibration of dosemeters and dosimetric research. The irradiation facilities of the laboratory comprise three X-ray machines covering the voltage range from 5 kV to 420 kV constant potential, a 60 Co teletherapy unit, a circular exposure system for routine batch calibration of personnel dosemeters with four gamma ray sources ( 60 Co and 137 Cs) and a reference source system with six gamma ray sources ( 60 Co and 137 Cs). In addition a set of calibrated beta ray sources are provided ( 147 Pm, 204 Tl and 90 Sr). The dosimetric equipment consists of three free-air parallelplate ionization chambers serving as primary standards of exposure for the X-ray energy region, graphite cavity chambers with measured volume as primary standards for the gamma radiation of 137 Cs and 60 Co as well as different secondary standard ionization chambers covering the dose rate range from the natural background level up to the level of modern therapy accelerators. In addition for high energy photon and electron radiation a graphite calorimeter is provided as primary standard of absorbed dose. The principle experimental set-ups for the practical use of the standards are presented and the procedures for the calibration of the different types of dosemeters are described. (Author)

Proton beam monitor chamber calibration

International Nuclear Information System (INIS)

Gomà, C; Meer, D; Safai, S; Lorentini, S

2014-01-01

The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences—of the order of 3%—were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth—i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers—rather than cylindrical chambers—for the reference dosimetry of pseudo-monoenergetic proton beams. (paper)

TRS 398 dosimetry protocol for radiotherapy

International Nuclear Information System (INIS)

Palmans, H.; Smyth, V.

2004-01-01

Full text: In recent years, international codes of practice based on absorbed dose to water standards have been published for the clinical reference dosimetry of external beams. It has become widely accepted that dosimetry of radiotherapeutic beams should be based on these standards. These codes of practice are a major improvement over earlier ones that used air kerma calibration factors as they are based on a calibration directly in a phantom in terms of the quantity of interest. The previous codes begin with calibration in air in terms of air kerma, then use theoretical and generic conversion factors to obtain dose to water that do not take account of chamber-to-chamber variation. Other good reasons for implementing the new codes are that they are conceptually simpler, include improved physical data and improve the consistency for various ionisation chamber types as well as between different beam types. TRS-3982,3 is a new Code of Practice (CoP) for reference dosimetry of external radiotherapy beams based on absorbed dose to, water calibrations and was published by the IAEA in a joint effort with the WHO, PAHO and ESTRO. It is the first CoP of its kind comprehensively covering all external radiotherapy beams except neutrons. The Radiotherapy Interest Group (RJG) of the ACPSEM has recommended that radiotherapy centres in Australia and New Zealand implement this CoP by the end of 2004. In this workshop, the general philosophy of the CoP will be outlined which will provide a framework for each of the individual subcodes. Although it represents just one of the potential implementations of the CoP, this workshop will deal only with dosimetry based on a cylindrical ionisation chamber with an absorbed dose calibration factor in 60Co from the standards laboratory. With the framework of the code in mind, it is straightforward to identify the basic steps that are required for measuring absorbed dose under reference conditions in a high-energy photon beam. The same is true

Uncertainties in the dosemeter calibration used for dosimetry in mammography; Incertezas na calibração de dosímetros utilizados para dosimetria em mamografia

Energy Technology Data Exchange (ETDEWEB)

Bianchi, Vivian C.R.N.; Evangelista, Claudete R.; Silva, Teógenes A. da, E-mail: vcrnb@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

This study aims to detail the sources of uncertainties and to estimate the combined standard uncertainties associated with the calibration procedure of dosimeters to be used in the dosimetry of X-ray bundles in mammography. A RADCAL ionization chamber, model RC6-M, and the semiconductor dosimeters UNFORS Xi and RADCAL Digitizer AGDM Accul-Gold were used. The calibration coefficients in terms of air kerma and uncertainties were obtained for the reference radiations of the W-Mo target-filter combinations. (author)

Workshop on measurement quality assurance for ionizing radiation: Proceedings

Energy Technology Data Exchange (ETDEWEB)

Heath, J.A.; Swinth, K.L. [comps.

1993-12-31

This workshop was held to review the status of secondary level calibration accreditation programs, review related measurement accreditation programs, document lessons learned, and to present changes in programs due to new national priorities involving radioactivity measurements. Contents include: fundamentals of measurement quality assurance (MQA), standards for MQA programs; perspectives and policies; complete MQA programs; future MQA programs; QA/QC programs--radioactivity; QA/QC programs--dosimetry; laboratory procedures for QA/QC; in-house control of reference dosimetry laboratories; in-house controls of radioactivity laboratories; and poster session. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

Workshop on measurement quality assurance for ionizing radiation: Proceedings

International Nuclear Information System (INIS)

Heath, J.A.; Swinth, K.L.

1993-01-01

This workshop was held to review the status of secondary level calibration accreditation programs, review related measurement accreditation programs, document lessons learned, and to present changes in programs due to new national priorities involving radioactivity measurements. Contents include: fundamentals of measurement quality assurance (MQA), standards for MQA programs; perspectives and policies; complete MQA programs; future MQA programs; QA/QC programs--radioactivity; QA/QC programs--dosimetry; laboratory procedures for QA/QC; in-house control of reference dosimetry laboratories; in-house controls of radioactivity laboratories; and poster session. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

Relative dosimetry by Ebt-3

International Nuclear Information System (INIS)

De Leon A, M. A.; Rivera M, T.; Hernandez O, J. O.

2015-10-01

In the present work relative dosimetry in two linear accelerator for radiation therapy was studied. Both Varian Oncology systems named Varian Clinac 2100-Cd and MLC Varian Clinac i X were used. Gaf Chromic Ebt-3 film was used. Measurements have been performed in a water equivalent phantom, using 6 MV and 18 MV photon beams on both Linacs. Both calibration and Electron irradiations were carried out with the ionization chamber placed at the isocenter, below a stack of solid water slabs, at the depth of dose maximum (D max), with a Source-to-Surface Distance (SSD) of 100 cm and a field size of 10 cm x 10 cm. Calibration and dosimetric measurements photons were carried out under IAEA-TRS 398 protocol. Results of relative dosimetry in the present work are discussed. (Author)

Collection of abstracts. 6. national symposium on radiation dosimetry

International Nuclear Information System (INIS)

1983-08-01

Abstracts are given of the total of 137 papers presented at the symposium. The papers discussed radiation dosimetry methods, dosemeters and detectors, the metrology and calibration of radiation sources, calibration standards, and radioactivity monitoring. (J.P.)

76 FR 18645 - Third Party Testing for Certain Children's Products; Notice of Requirements for Accreditation of...

Science.gov (United States)

2011-04-05

... to the International Standards Organization (ISO)/International Electrotechnical Commission (IEC) Standard ISO/IEC 17025:2005, ``General Requirements for the Competence of Testing and Calibration... paint ban and 16 CFR part 1303, it must be accredited to ISO/IEC 17025- 2005 by an accreditation body...

Dosimetry systems for radiation processing

International Nuclear Information System (INIS)

McLaughlin, W.L.; Desrosiers, M.F.

1995-01-01

Dosimetry serves important functions in radiation processing, where large absorbed doses and dose rates from photon and electron sources have to be measured with reasonable accuracy. Proven dosimetry systems are widely used to perform radiation measurements in development of new processes, validation, qualification and verification (quality control) of established processes and archival documentation of day-to-day and plant-to-plant processing uniformity. Proper calibration and traceability of routine dosimetry systems to standards are crucial to the success of many large-volume radiation processes. Recent innovations and advances in performance of systems that enhance radiation measurement assurance and process diagnostics include dose-mapping media (new radiochromic film and solutions), optical waveguide systems for food irradiation, solid-state devices for real-time and passive dosimetry over wide dose-rate and dose ranges, and improved analytical instruments and data acquisition. (author)

Group: radiation dosimetry

International Nuclear Information System (INIS)

Caldas, L.V.E.

1990-01-01

The main activities of the radiation dosimetry group is described, including the calibration of instruments, sources and radioactive solutions and the determination of neutron flux; development, production and market dosimetric materials; development radiation sensor make the control of radiation dose received by IPEN workers; development new techniques for monitoring, etc. (C.G.C.)

Time-resolved diode dosimetry calibration through Monte Carlo modeling for in vivo passive scattered proton therapy range verification.

Science.gov (United States)

Toltz, Allison; Hoesl, Michaela; Schuemann, Jan; Seuntjens, Jan; Lu, Hsiao-Ming; Paganetti, Harald

2017-11-01

Our group previously introduced an in vivo proton range verification methodology in which a silicon diode array system is used to correlate the dose rate profile per range modulation wheel cycle of the detector signal to the water-equivalent path length (WEPL) for passively scattered proton beam delivery. The implementation of this system requires a set of calibration data to establish a beam-specific response to WEPL fit for the selected 'scout' beam (a 1 cm overshoot of the predicted detector depth with a dose of 4 cGy) in water-equivalent plastic. This necessitates a separate set of measurements for every 'scout' beam that may be appropriate to the clinical case. The current study demonstrates the use of Monte Carlo simulations for calibration of the time-resolved diode dosimetry technique. Measurements for three 'scout' beams were compared against simulated detector response with Monte Carlo methods using the Tool for Particle Simulation (TOPAS). The 'scout' beams were then applied in the simulation environment to simulated water-equivalent plastic, a CT of water-equivalent plastic, and a patient CT data set to assess uncertainty. Simulated detector response in water-equivalent plastic was validated against measurements for 'scout' spread out Bragg peaks of range 10 cm, 15 cm, and 21 cm (168 MeV, 177 MeV, and 210 MeV) to within 3.4 mm for all beams, and to within 1 mm in the region where the detector is expected to lie. Feasibility has been shown for performing the calibration of the detector response for three 'scout' beams through simulation for the time-resolved diode dosimetry technique in passive scattered proton delivery. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Upgrading the Medical Physics Calibration Laboratory Towards ISO/IEC 17025: Radiation Standards and Calibration in Diagnostic Radiology

International Nuclear Information System (INIS)

Asmaliza Hashim; Muhammad Jamal Md Isa; Abd Aziz Mhd Ramli; Wan Hazlinda Ismail; Norhayati Abdullah; Shahrul Azlan Azizan; Siti Sara Deraman; Nor Azlin Azraai; Md Khairusalih Md Zin

2010-01-01

Calibration of quality control (QC) test tools used in diagnostic radiology is legally required under the Ministry of Health (MOH) requirement. The Medical Physics Calibration Laboratory of the Malaysian Nuclear Agency is the national focal point for the calibration of quality control test tools used in diagnostic radiology. The Medical Physics Calibration Laboratory has measurement traceability to primary standard dosimetry laboratory (Physikalisch-Technische Bundesanstalt (PTB)), thus providing an interface between the primary standard dosimetry laboratory and Malaysian hospitals, clinics and license class H holder. The Medical Physics Calibration Laboratory facility is comprised of a constant potential x-ray system with a capability of 160 kV tube and a series of reference and working standard ion chambers. The stability of reference and working standard ion chambers was measured using strontium-90. Dosimetric instruments used in diagnostic radiology is calibrated in terms of air kerma to comply with an International Code of Practices of dosimetry for example IAEA's Technical Report Series number 457. The new series of standard radiation qualities was established based on ISO/IEC 61267. The measurement of beam homogeneity was measured using film and ion chamber to define the field size at certain distance and kV output was measured using the spectrometer and non-invasive kVp meter. The uncertainties measurement was determined with expended uncertainties to a level of confidence of approximately 95% (coverage factor k=2). This paper describes the available facility and the effort of the Medical Physics Calibration Laboratory to upgrade the laboratory towards ISO/IEC 17025. (author)

Field calibration of PADC track etch detectors for local neutron dosimetry in man using different radiation qualities

Energy Technology Data Exchange (ETDEWEB)

Haelg, Roger A., E-mail: rhaelg@phys.ethz.ch [Institute for Radiotherapy, Radiotherapie Hirslanden AG, Hirslanden Medical Center, Rain 34, CH-5000 Aarau (Switzerland); Besserer, Juergen [Institute for Radiotherapy, Radiotherapie Hirslanden AG, Hirslanden Medical Center, Rain 34, CH-5000 Aarau (Switzerland); Boschung, Markus; Mayer, Sabine [Division for Radiation Safety and Security, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Clasie, Benjamin [Department of Radiation Oncology, Massachusetts General Hospital, 30 Fruit Street, Boston, MA 02114 (United States); Kry, Stephen F. [Department of Radiation Physics, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030 (United States); Schneider, Uwe [Institute for Radiotherapy, Radiotherapie Hirslanden AG, Hirslanden Medical Center, Rain 34, CH-5000 Aarau (Switzerland); Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 204, CH-8057 Zurich (Switzerland)

2012-12-01

In order to quantify the dose from neutrons to a patient for contemporary radiation treatment techniques, measurements inside phantoms, representing the patient, are necessary. Published reports on neutron dose measurements cover measurements performed free in air or on the surface of phantoms and the doses are expressed in terms of personal dose equivalent or ambient dose equivalent. This study focuses on measurements of local neutron doses inside a radiotherapy phantom and presents a field calibration procedure for PADC track etch detectors. An initial absolute calibration factor in terms of H{sub p}(10) for personal dosimetry is converted into neutron dose equivalent and additional calibration factors are derived to account for the spectral changes in the neutron fluence for different radiation therapy beam qualities and depths in the phantom. The neutron spectra used for the calculation of the calibration factors are determined in different depths by Monte Carlo simulations for the investigated radiation qualities. These spectra are used together with the energy dependent response function of the PADC detectors to account for the spectral changes in the neutron fluence. The resulting total calibration factors are 0.76 for a photon beam (in- and out-of-field), 1.00 (in-field) and 0.84 (out-of-field) for an active proton beam and 1.05 (in-field) and 0.91 (out-of-field) for a passive proton beam, respectively. The uncertainty for neutron dose measurements using this field calibration method is less than 40%. The extended calibration procedure presented in this work showed that it is possible to use PADC track etch detectors for measurements of local neutron dose equivalent inside anthropomorphic phantoms by accounting for spectral changes in the neutron fluence.

Dosemeter calibration in X-ray and in cobalt-60

International Nuclear Information System (INIS)

Silva, T.A. da

1988-01-01

Some tests about quality security for clinical dosemeter calibration in secondary standard dosimetry laboratory are described. The tests in gama calibration system, in X-ray calibration, in secondary standard dosimeter, in the dosemeter that will be calibrated, during the calibration and after the calibration are shown. (C.G.C.) [pt

Improving calibration accuracy in gel dosimetry

International Nuclear Information System (INIS)

Oldham, M.; McJury, M.; Webb, S.; Baustert, I.B.; Leach, M.O.

1998-01-01

A new method of calibrating gel dosimeters (applicable to both Fricke and polyacrylamide gels) is presented which has intrinsically higher accuracy than current methods, and requires less gel. Two test-tubes of gel (inner diameter 2.5 cm, length 20 cm) are irradiated separately with a 10x10cm 2 field end-on in a water bath, such that the characteristic depth-dose curve is recorded in the gel. The calibration is then determined by fitting the depth-dose measured in water, against the measured change in relaxivity with depth in the gel. Increased accuracy is achieved in this simple depth-dose geometry by averaging the relaxivity at each depth. A large number of calibration data points, each with relatively high accuracy, are obtained. Calibration data over the full range of dose (1.6-10 Gy) is obtained by irradiating one test-tube to 10 Gy at dose maximum (D max ), and the other to 4.5 Gy at D max . The new calibration method is compared with a 'standard method' where five identical test-tubes of gel were irradiated to different known doses between 2 and 10 Gy. The percentage uncertainties in the slope and intercept of the calibration fit are found to be lower with the new method by a factor of about 4 and 10 respectively, when compared with the standard method and with published values. The gel was found to respond linearly within the error bars up to doses of 7 Gy, with a slope of 0.233±0.001 s -1 Gy -1 and an intercept of 1.106±0.005 Gy. For higher doses, nonlinear behaviour was observed. (author)

Survey of international personnel radiation dosimetry programs

International Nuclear Information System (INIS)

Swaja, R.E.

1985-04-01

In September of 1983, a mail survey was conducted to determine the status of external personnel gamma and neutron radiation dosimetry programs at international agencies. A total of 130 agencies participated in this study including military, regulatory, university, hospital, laboratory, and utility facilities. Information concerning basic dosimeter types, calibration sources, calibration phantoms, corrections to dosimeter responses, evaluating agencies, dose equivalent reporting conventions, ranges of typical or expected dose equivalents, and degree of satisfaction with existing systems was obtained for the gamma and neutron personnel monitoring programs at responding agencies. Results of this survey indicate that to provide the best possible occupational radiation monitoring programs and to improve dosimetry accuracy in performance studies, facility dosimetrists, regulatory and standards agencies, and research laboratories must act within their areas of responsibility to become familiar with their radiation monitoring systems, establish common reporting guidelines and performance standards, and provide opportunities for dosimetry testing and evaluation. 14 references, 10 tables

Dosimetry for electron beam sterilization

International Nuclear Information System (INIS)

Miller, A.

2007-01-01

According to ISO 11137-1 (sect 4.3.4) dosimetry used in the development, validation and routine control of the sterilization process shall have measurement traceability to national or international standards and shall have a known level of uncertainty. It can only be obtained through calibration of the dosimeters. In presented lecture different types of dosimeter systems for electron beams (calorimeters, radiochromic film dosimeters, alanine / EPR) and their calibration are described

External dosimetry - Applications to radiation protection

International Nuclear Information System (INIS)

Faussot, Alain

2011-01-01

Dosimetry is the essential component of radiation protection. It allows to determine by calculation and measurement the absorbed dose value, i.e. the energy amounts deposited in matter by ionizing radiations. It deals also with the irradiation effects on living organisms and with their biological consequences. This reference book gathers all the necessary information to understand and master the external dosimetry and the metrology of ionizing radiations, from the effects of radiations to the calibration of radiation protection devices. The first part is devoted to physical dosimetry and allows to obtain in a rigorous manner the mathematical formalisms leading to the absorbed dose for different ionizing radiation fields. The second part presents the biological effects of ionizing radiations on living matter and the determination of a set of specific radiation protection concepts and data to express the 'risk' to develop a radio-induced cancer. The third part deals with the metrology of ionizing radiations through the standardized study of the methods used for the calibration of radiation protection equipments. Some practical exercises with their corrections are proposed at the end of each chapter

Calibration curves for biological dosimetry by drug-induced prematurely condensed chromosomes in human lymphocytes

International Nuclear Information System (INIS)

Kang, C. M.; Chung, H. C.; Cho, C. K.

2002-01-01

To develop the cytogenetic tool to detect chromosome damages after high dose exposure with 60 Coγ- rays, dose-response curves were measured for induction of prematurely condensed chromosomes (PCC) in peripheral lymphocytes. Blood was obtained from 10 different healthy donors, and given okadaic acid (OA) 500nM in cultured lymphocytes 1h after radiation exposure. Cells were analyzed by the frequencies of OA-induced PCC rings because it is difficult to obtain mitotic chromosomes using a conventional chromosome aberration (CA). PCC-rings were scored in cells exposed in the dose range of 0.2-16Gy. The frequency of the cells with PCC and the dose-response relationship for the yield of PCC rings were examined in the irradiated lymphocytes. The yield of PCC-rings increased with dose dependent-manner up to 16Gy. The observed dose-effect relationship for the percentage of cells with PCC-rings was calculated by linear-quadratic model. This technique can be applied to biological dosimetry of radiation exposures involving whole body irradiation to allow damaged chromosomes to be detected with great sensitivity. Detection of okadaic acid-induced PCC rings is a useful method up to 16Gy or more doses in estimating the absorbed doses of victims after high dose exposure. Calibration curves described in this paper will be used in our laboratory for biological dosimetry by PCC-ring after a high dose exposure

On multichannel film dosimetry with channel-independent perturbations

International Nuclear Information System (INIS)

Méndez, I.; Peterlin, P.; Hudej, R.; Strojnik, A.; Casar, B.

2014-01-01

Purpose: Different multichannel methods for film dosimetry have been proposed in the literature. Two of them are the weighted mean method and the method put forth byMicke et al. [“Multichannel film dosimetry with nonuniformity correction,” Med. Phys. 38, 2523–2534 (2011)] and Mayer et al. [“Enhanced dosimetry procedures and assessment for EBT2 radiochromic film,” Med. Phys. 39, 2147–2155 (2012)]. The purpose of this work was to compare their results and to develop a generalized channel-independent perturbations framework in which both methods enter as special cases. Methods: Four models of channel-independent perturbations were compared: weighted mean, Micke–Mayer method, uniform distribution, and truncated normal distribution. A closed-form formula to calculate film doses and the associated type B uncertainty for all four models was deduced. To evaluate the models, film dose distributions were compared with planned and measured dose distributions. At the same time, several elements of the dosimetry process were compared: film type EBT2 versus EBT3, different waiting-time windows, reflection mode versus transmission mode scanning, and planned versus measured dose distribution for film calibration and for γ-index analysis. The methods and the models described in this study are publicly accessible through IRISEU. Alpha 1.1 ( http://www.iriseu.com ). IRISEU. is a cloud computing web application for calibration and dosimetry of radiochromic films. Results: The truncated normal distribution model provided the best agreement between film and reference doses, both for calibration and γ-index verification, and proved itself superior to both the weighted mean model, which neglects correlations between the channels, and the Micke–Mayer model, whose accuracy depends on the properties of the sensitometric curves. With respect to the selection of dosimetry protocol, no significant differences were found between transmission and reflection mode scanning

On multichannel film dosimetry with channel-independent perturbations

Energy Technology Data Exchange (ETDEWEB)

Méndez, I., E-mail: nmendez@onko-i.si; Peterlin, P.; Hudej, R.; Strojnik, A.; Casar, B. [Department of Medical Physics, Institute of Oncology Ljubljana, Zaloška cesta 2, Ljubljana 1000 (Slovenia)

2014-01-15

Purpose: Different multichannel methods for film dosimetry have been proposed in the literature. Two of them are the weighted mean method and the method put forth byMicke et al. [“Multichannel film dosimetry with nonuniformity correction,” Med. Phys. 38, 2523–2534 (2011)] and Mayer et al. [“Enhanced dosimetry procedures and assessment for EBT2 radiochromic film,” Med. Phys. 39, 2147–2155 (2012)]. The purpose of this work was to compare their results and to develop a generalized channel-independent perturbations framework in which both methods enter as special cases. Methods: Four models of channel-independent perturbations were compared: weighted mean, Micke–Mayer method, uniform distribution, and truncated normal distribution. A closed-form formula to calculate film doses and the associated type B uncertainty for all four models was deduced. To evaluate the models, film dose distributions were compared with planned and measured dose distributions. At the same time, several elements of the dosimetry process were compared: film type EBT2 versus EBT3, different waiting-time windows, reflection mode versus transmission mode scanning, and planned versus measured dose distribution for film calibration and for γ-index analysis. The methods and the models described in this study are publicly accessible through IRISEU. Alpha 1.1 ( http://www.iriseu.com ). IRISEU. is a cloud computing web application for calibration and dosimetry of radiochromic films. Results: The truncated normal distribution model provided the best agreement between film and reference doses, both for calibration and γ-index verification, and proved itself superior to both the weighted mean model, which neglects correlations between the channels, and the Micke–Mayer model, whose accuracy depends on the properties of the sensitometric curves. With respect to the selection of dosimetry protocol, no significant differences were found between transmission and reflection mode scanning

Results of the dosimetry intercomparison

International Nuclear Information System (INIS)

Dure, Elsa S.

2000-07-01

The appropriate way to verify the accuracy of the results of dose reported by the laboratories that offer lend personal dosimetry service is in the periodic participation of round of intercomparison dosimetry, undertaken by laboratories whose standards are trace (Secondary Laboratory). The Laboratory of External Personal Dosimetry of the CNEA-PY has participated in three rounds of intercomparison. The first two were organized in the framework of the Model Project RLA/9/030 RADIOLOGICAL WASTE SECURITY, and the irradiations were carried out in the Laboratory of Regional Calibration of the Center of Nuclear Technology Development, Belo Horizonte-Brazil (1998) and in the National Laboratory of Metrology of the ionizing radiations of the Institute of Radioprotection and Dosimetry, Rio de Janeiro-Brazil (1999). The third was organized by the IAEA and the irradiations were made in the Physikalisch-Technische Bundesanstalt PTB, Braunschweig - Federal Republic of Germany (1999-2000) [es

States Moving from Accreditation to Accountability. Accreditation: State School Accreditation Policies

Science.gov (United States)

Wixom, Micah Ann

2014-01-01

Accreditation policies vary widely among the states. Since Education Commission of the States last reviewed public school accreditation policies in 1998, a number of states have seen their legislatures take a stronger role in accountability--resulting in a move from state-administered accreditation systems to outcomes-focused state accountability…

Dosimetry practices at the Radiation Technology Centre (Ghana)

International Nuclear Information System (INIS)

Emi-Reynolds, G.; Banini, G.K.; Ennison, I.

1997-01-01

Dosimetry practices undertaken to support research and pilot scale gamma irradiation activities at the Radiation Technology Centre of the Ghana Atomic Energy Commission are presented. The Fricke dosemeter was used for calibrating the gamma field of the gammacell-220. The Fricke system and the gammacell-220 were then used to calibrate the ethanol chlorobenzene (ECB) dosemeter. The Fricke and ECB dosemeter systems have become routine dosemeters at the centre. Dosimetry work has covered a wide range of research specimens and pilot scale products to establish the relevant irradiation protocol and parameters for routine treatment. These include yams, pineapple explants, blood for feeding tsetseflies, cocoa bud wood and cassava sticks. Pilot scale dosimetry studies on maize, medical devices like intravenous infusion sets and surgical gauze have also been completed. The results and observations made on some of these products are reported. (author). 4 refs., 5 figs

Statistical analysis of personal dosimetry of exposed workers; Analisis estadistico de la dosimetria personal de trabajadores expuestos

Energy Technology Data Exchange (ETDEWEB)

Sanchez Munoz, F. J.; Alejo Luque, L.; Mas Munoz, I.; Serrada Hierro, A.

2013-07-01

The dosimetry centers accredited by the Nuclear Safety Council (CSN) normally report overcoming legal limits, or some fraction thereof, but do not provide comparative dosimetric criteria indicating if assigned to a given dose is large TPE or small relative to that of their peers. In order to help to resolve the difficulties mentioned ds, it has developed an application that statistically processes the dosimetric data provided by the National Dosimetry Center. (Author)

Guidelines on calibration of neutron measuring devices

International Nuclear Information System (INIS)

Burger, G.

1988-01-01

The International Atomic Energy Agency and the World Health Organization have agreed to establish an IAEA/WHO Network of Secondary Standard Dosimetry Laboratories (SSDLs) in order to improve accuracy in applied radiation dosimetry throughout the world. These SSDLs must be equipped with, and maintain, secondary standard instruments, which have been calibrated against primary standards, and must be nominated by their governments for membership of the network. The majority of the existing SSDLs were established primarily to work with photon radiation (X-rays and gamma rays). Neutron sources are, however, increasingly being applied in industrial processes, research, nuclear power development and radiation biology and medicine. Thus, it is desirable that the SSDLs in countries using neutron sources on a regular basis should also fulfil the minimum requirements to calibrate neutron measuring devices. It is the primary purpose of this handbook to provide guidance on calibration of instruments for radiation protection. A calibration laboratory should also be in a position to calibrate instrumentation being used for the measurement of kerma and absorbed dose and their corresponding rates. This calibration is generally done with photons. In addition, since each neutron field is usually contaminated by photons produced in the source or by scatter in the surrounding media, neutron protection instrumentation has to be tested with respect to its intrinsic photon response. The laboratory will therefore need to possess equipment for photon calibration. This publication deals primarily with methods of applying radioactive neutron sources for calibration of instrumentation, and gives an indication of the space, manpower and facilities needed to fulfil the minimum requirements of a calibration laboratory for neutron work. It is intended to serve as a guide for centres about to start on neutron dosimetry standardization and calibration. 94 refs, 8 figs, 12 tabs

Variations of influence quantities in industrial irradiators and their effect on dosimetry performance

International Nuclear Information System (INIS)

Chu, R.D.H.

1999-01-01

Many environmental factors, including irradiation temperature, post-irradiation storage temperature, dose rate, relative humidity, oxygen content and the energy spectrum may affect the response of dosimetry systems used in industrial radiation processing. Although the effects of individual influence quantities have been extensively studied, the variations of these influence quantities in production irradiators and the complex relationships between the effects of different influence quantities make it difficult to assess the overall effect on the measurement uncertainty. In the development of new dosimetry systems it is important to know the effect of each influence quantity and developers of new dosimetry systems should perform studies over a wide range of irradiation conditions. Analysis parameters and manufacturing specifications should be chosen to minimize the effect of influence quantities in the environments where the dosimeters will be used. Because of possible relationships between different influence quantities, care must be taken to ensure that the response function determined in the calibration of the dosimetry system is applicable for the conditions in which the dosimeters will be used. Reference standard dosimetry systems which have been thoroughly studied and have known relationships between dose response and influence quantities should be used to verify the calibration of routine dosimetry systems under the actual conditions of use. Better understanding of the variations in influence quantities in industrial irradiators may be obtained by modeling or direct measurements and may provide improvements in the calibration of routine dosimetry system and reduction of the overall measurement uncertainty. (author)

Field dosimetry on sterilization area of medical-hospitable materials

International Nuclear Information System (INIS)

Mariano, C.S.T.P.; Campos, L.L.

1992-01-01

The calcium sulfate doped with dysprosium, used in high dose dosimetry by electron paramagnetic resonance (EPR), is studied on field dosimetry for medical-hospitable materials sterilization. The calibration curves of EPR signal in function of absorbed dose in air and the thermal decay of EPR signal at room temperature are also presented. (C.G.C)

Dosimetry techniques applied to thermoluminescent age estimation

International Nuclear Information System (INIS)

Erramli, H.

1986-12-01

The reliability and the ease of the field application of the measuring techniques of natural radioactivity dosimetry are studied. The natural radioactivity in minerals in composed of the internal dose deposited by alpha and beta radiations issued from the sample itself and the external dose deposited by gamma and cosmic radiations issued from the surroundings of the sample. Two technics for external dosimetry are examined in details. TL Dosimetry and field gamma dosimetry. Calibration and experimental conditions are presented. A new integrated dosimetric method for internal and external dose measure is proposed: the TL dosimeter is placed in the soil in exactly the same conditions as the sample ones, during a time long enough for the total dose evaluation [fr

Technical basis document for internal dosimetry

CERN Document Server

Hickman, D P

1991-01-01

This document provides the technical basis for the Chem-Nuclear Geotech (Geotech) internal dosimetry program. Geotech policy describes the intentions of the company in complying with radiation protection standards and the as low as reasonably achievable (ALARA) program. It uses this policy and applicable protection standards to derive acceptable methods and levels of bioassay to assure compliance. The models and computational methods used are described in detail within this document. FR-om these models, dose- conversion factors and derived limits are computed. These computations are then verified using existing documentation and verification information or by demonstration of the calculations used to obtain the dose-conversion factors and derived limits. Recommendations for methods of optimizing the internal dosimetry program to provide effective monitoring and dose assessment for workers are provided in the last section of this document. This document is intended to be used in establishing an accredited dosi...

Guidelines for the calibration of personnel dosimeters

International Nuclear Information System (INIS)

Roberson, P.L.; Holbrook, K.L.

1984-01-01

This guide describes minimum acceptable performance levels for personnel dosimetry systems used at Department of Energy (DOE) facilities. The goal is to improve both the quality of radiological calibrations and the methods of comparing reported occupational doses between DOE facilities. Reference calibration techniques are defined. A standard for evaluation of personnel dosimetry systems and recommended design parameters for personnel dosimeters are also included. Approximate intervals for the radiation energies for which these guidelines are appropriate are 15 keV to 2 MeV for photons; above 0.3 MeV for beta particles; and 1 keV to 2 MeV for neutrons. An analysis of ANSI N13.11 was completed using performance evaluations of selected personnel dosimetry systems in use at DOE facilities. The results of this analysis are incorporated in the guidelines

IAEA/WHO TLD postal dose audit service and high precision measurements for radiotherapy level dosimetry

International Nuclear Information System (INIS)

Izewska, J.; Bera, P.; Vatnitsky, S.

2002-01-01

Since 1969 the International Atomic Energy Agency, together with the World Health Organization, has performed postal TLD audits to verify calibration of radiotherapy beams in developing countries. The TLD programme also monitors activities of Secondary Standard Dosimetry Laboratories (SSDLs). The programme has checked approximately 4000 clinical beams in over 1100 hospitals, and in many instances significant errors have been detected in the beam calibration. Subsequent follow-up actions help to resolve the discrepancies, thus preventing further mistreatment of patients. The audits for SSDLs check the implementation of the dosimetry protocol in order to assure proper dissemination of dosimetry standards to the end-users. The TLD audit results for SSDLs show good consistency in the basic dosimetry worldwide. New TLD procedures and equipment have recently been introduced by the IAEA that include a modified TLD calibration methodology and computerised tools for automation of dose calculation from TLD readings. (author)

Implementation of the International Code of Practice on Dosimetry in Diagnostic Radiology (TRS 457): Review of Test Results

International Nuclear Information System (INIS)

2011-01-01

In 2007, the IAEA published Dosimetry in Diagnostic Radiology: An International Code of Practice (IAEA Technical Reports Series No. 457). This publication recommends procedures for calibration and dosimetric measurement for the attainment of standardized dosimetry. It also addresses requirements both in standards dosimetry laboratories, especially Secondary Standards Dosimetry Laboratories (SSDLs), and in clinical centres for radiology, as found in most hospitals. The implementation of TRS No. 457 decreases the uncertainty in the dosimetry of diagnostic radiology beams and provides Member States with a unified and consistent framework for dosimetry in diagnostic radiology, which previously did not exist. A coordinated research project (CRP E2.10.06) was established in order to provide practical guidance to professionals at SSDLs and to clinical medical physicists on the implementation of TRS No. 457. This includes the calibration of radiological dosimetry instrumentation, the dissemination of calibration coefficients to clinical centres and the establishment of dosimetric measurement processes in clinical settings. The main goals of the CRP were to: Test the procedures recommended in TRS No. 457 for calibration of radiation detectors in different types of diagnostic beams and measuring instruments for varying diagnostic X ray modalities; Test the clinical dosimetry procedures, including the use of phantoms and patient dose surveys; Report on the practical implementation of TRS No. 457 at both SSDLs and hospital sites. Testing of TRS No. 457 was performed by a group of medical physicists from hospitals and SSDLs from various institutions worldwide

Calibration of well-type ionization chambers

International Nuclear Information System (INIS)

Alves, C.F.E.; Leite, S.P.; Pires, E.J.; Magalhaes, L.A.G.; David, M.G.; Almeida, C.E. de

2015-01-01

This paper presents the methodology developed by the Laboratorio de Ciencias Radiologicas and presently in use for determining of the calibration coefficient for well-type chambers used in the dosimetry of 192 Ir high dose rate sources. Uncertainty analysis involving the calibration procedure are discussed. (author)

CABAS: A freely available PC program for fitting calibration curves in chromosome aberration dosimetry

International Nuclear Information System (INIS)

Deperas, J.; Szluiska, M.; Deperas-Kaminska, M.; Edwards, A.; Lloyd, D.; Lindholm, C.; Romm, H.; Roy, L.; Moss, R.; Morand, J.; Wojcik, A.

2007-01-01

The aim of biological dosimetry is to estimate the dose and the associated uncertainty to which an accident victim was exposed. This process requires the use of the maximum-likelihood method for fitting a calibration curve, a procedure that is not implemented in most statistical computer programs. Several laboratories have produced their own programs, but these are frequently not user-friendly and not available to outside users. We developed a software for fitting a linear-quadratic dose-response relationship by the method of maximum-likelihood and for estimating a dose from the number of aberrations observed. The program called as CABAS consists of the main curve-fitting and dose estimating module and modules for calculating the dose in cases of partial body exposure, for estimating the minimum number of cells necessary to detect a given dose of radiation and for calculating the dose in the case of a protracted exposure. (authors)

Total skin high-dose-rate electron therapy dosimetry using TG-51

International Nuclear Information System (INIS)

Gossman, Michael S.; Sharma, Subhash C.

2004-01-01

An approach to dosimetry for total skin electron therapy (TSET) is discussed using the currently accepted TG-51 high-energy calibration protocol. The methodology incorporates water phantom data for absolute calibration and plastic phantom data for efficient reference dosimetry. The scheme is simplified to include the high-dose-rate mode conversion and provides support for its use, as it becomes more available on newer linear accelerators. Using a 6-field, modified Stanford technique, one may follow the process for accurate determination of absorbed dose

Secondary standard dosimetry laboratory at INFLPR

Energy Technology Data Exchange (ETDEWEB)

Scarlat, F.; Minea, R.; Scarisoreanu, A.; Badita, E.; Sima, E.; Dumitrascu, M.; Stancu, E.; Vancea, C., E-mail: scarlat.f@gmail.com [National Institute for Laser, Plasma and Radiation Physics - INFLPR, Bucharest (Romania)

2011-07-01

National Institute for Laser, Plasma and Radiation Physics (INFLPR) has constructed a High Energy Secondary Standard Dosimetry Laboratory SSDL-STARDOOR - for performing dosimetric calibrations according to ISO IEC SR/EN 17025:2005 standards. This is outfitted with UNIDOS Secondary Standard Dosimeter from PTW (Freiburg Physikalisch-Technische Werksttaten) calibrated at the PTB-Braunschweig (German Federal Institute of Physics and Metrology). A radiation beam of the quality of Q used by our laboratory as calibration source are provided by INFLPR 7 MeV electron beam linear accelerator mounted in our facility. (author)

The Radiotherapy Dosimetry Audit System In the UK

International Nuclear Information System (INIS)

Thwaites, D.I.

1999-01-01

Two national radiotherapy dosimetry intercomparisons have been earned out in the UK, involving all radiotherapy institutes. The first was concerned with megavoltage photon beams and looked at beam calibration and simple three-field planned distributions in a geometric phantom. The intercomparisons were carried out by an independent intercomparison physicist visiting each department in turn and making measurements with ion chambers, following a fixed protocol. The beam calibration intercomparison was earned out on every 60 C o beam and every MV x-ray beam, whilst the planned comparisons were carried out on one beam only. The plans included effects of wedges, oblique incidence and inhomogeneities. The study was unfunded and took a significant time (1988-1991) to cover the 65 or so centres. It was followed up by a national electron dosimetry intercomparison which was fended (Department of Health) and which ran from 1994-1996. This audited three electron beam energies in each centre (depth dose, beam energy, dose calibration) and also included a follow-up of the original photon beam intercomparison. In general these studies showed good consistency of dosimetry across the UK centres, with mean (measured/locally stated) doses being close to unity and standard deviations of the distributions of values being approx. 1.5 and 1% for photons, 1.8% for electrons for beam calibration and 2.5-3.5% for the planned multi-beam situations. 97-100% of measurements were within the pre-set 3% tolerance for beam calibration and around 90% of the measurements within a pre-set 5% tolerance for planned situations. The studies did highlight some areas where increased on Q A could provide benefits. In particular the photon intercomparison discovered one 60 C o unit mis calibration which led to national recommendations for the implementation of Quality Systems in radiotherapy departments

[Determining biomedical equipment calibration in health care Institutions in the Risaralda Department of Colombia].

Science.gov (United States)

López-Isaza, Giovanni A; Llamosa-Rincón, Luis E

2008-01-01

Determining quality features related to tracking biomedical equipment calibration patterns and their electrical safety as implemented by Health Care Institutions in the Risaralda department. This was a descriptive study using non-probabilistic sampling and the criterion of a greater equipment inventory and service demand for Clinics, Aesthetic, Radiology and Dentistry Centres and Hospitals. Census; the instrument was applied to 32 health-care institutions distributed throughout the Risaralda departments 14 municipalities between September 2005 and January 2006. Hospitals was the category having a highest number of electro-medical equipment (56%). Pereira (the capital of Risaralda) had 81% of all electro-medical equipment. All the institutions lacked NTC-ISO-IEC-17025 accreditation regarding standards certified by the Superintendence of Industry and Commerce. None of the institutions externally contracted by the institutions being surveyed was accredited. There is a public health risk in the Risaralda department; all health-care institutions lacked NTC-ISO-IEC-17025 accreditation and external institutions (in turn being hired by them for calibrating their equipment) also lacked accreditation. Based on the information obtained from non-calibrated equipment having international patterns, there is a great danger that determining the quality of biomedical equipment calibration patterns may be erroneous. It also places health-care institutions at a competitive disadvantage when compared to other accredited institutions in Colombia or in other countries.

Dosimetry for Electron Beam Applications

DEFF Research Database (Denmark)

Miller, Arne

1983-01-01

This report describes two aspects of electron bean dosimetry, on one hand developaent of thin fil« dosimeters and measurements of their properties, and on the other hand developaent of calorimeters for calibration of routine dosimeters, e.g. thin films. Two types of radiochromic thin film...

Role of secondary standard dosimetry laboratory in radiation protection program

International Nuclear Information System (INIS)

Rahman, Sohaila; Ali, Noriah Mohd.

2008-01-01

Full text: The radiation dosimetry program is an important element of operational radiation protection. Dosimetry data enable workers and radiation protection professionals to evaluate and control work practices to eliminate unnecessary exposure to ionizing radiation. The usefulness of the data produced however depends on its quality and traceability. The emphasis of the global dosimetry program is focused through the IAEA/WHO network of secondary standard dosimetry laboratories (SSDLs), which aims for the determination of SI quantities through proper traceable calibration of radiation protection equipment. The responsibility of SSDL-NUCLEAR MALAYSIA to guarantee a reliable dosimetry service, which is traceable to international standards, is elucidated. It acts as the basis for harmonized occupational radiation monitoring in Malaysia.

76 FR 52548 - National Veterinary Accreditation Program; Currently Accredited Veterinarians Performing...

Science.gov (United States)

2011-08-23

.... APHIS-2006-0093] RIN 0579-AC04 National Veterinary Accreditation Program; Currently Accredited... accredited in the National Veterinary Accreditation Program (NVAP) may continue to perform accredited duties..., 2011. FOR FURTHER INFORMATION CONTACT: Dr. Todd Behre, National Veterinary Accreditation Program, VS...

Comparative study among calibration methods of clinical applicators of beta radiation

International Nuclear Information System (INIS)

Antonio, Patricia de Lara

2009-01-01

90 Sr+ 90 Y clinical applicators are instruments used in brachytherapy procedures and they have to be periodically calibrated, according to international standards and recommendations. In this work, four calibration methods of dermatological and ophthalmic applicators were studied, comparing the results with those given by the calibration certificates of the manufacturers. The methods included the use of the standard applicator of the Calibration Laboratory (LCI), calibrated by the National Institute of Standards and Technology; an Amersham applicator (LCI) as reference; a mini-extrapolation chamber developed at LCI as an absolute standard; and thermoluminescent dosimetry. The mini-extrapolation chamber and a PTW commercial extrapolation chamber were studied in relation to their performance through quality control tests of their response, as leakage current, repeatability and reproducibility. The distribution of the depth dose in water, that presents high importance in dosimetry of clinical applicators, was determined using the mini extrapolation chamber and the thermoluminescent dosimeters. The results obtained were considered satisfactory for the both cases, and comparable to the data of the IAEA (2002) standard. Furthermore, a dosimetry postal kit was developed for the calibration of clinical applicators using the thermoluminescent technique, to be sent to clinics and hospitals, without the need of the transport of the sources to IPEN for calibration. (author)

The role of the IAEA Dosimetry Laboratory in the dissemination of standards for radiation protection

International Nuclear Information System (INIS)

Czap, L.; Andreo, P.; Matscheko, G.

1998-01-01

Approximately 90% of the Secondary Standard Dosimetry Laboratories (SSDLs) provide users with calibrations of radiation protection instruments, and the IAEA is taking every necessary effort to insure that SSDLs measurements are traceable to Primary Standards. The Agency has proper radiation sources available to provide traceable calibrations to the SSDLs involved in measurements on diagnostic x-ray generators, including an x-ray unit specifically for mammography dedicated to standardization procedures. The different photon beam qualities and calibration procedures available in the Agency's Dosimetry Laboratory are described

Automation of the Calibration of Reference Dosimeters Used in Radiotherapy

International Nuclear Information System (INIS)

Romero Acosta, A.; Gutierrez Lores, S.

2013-01-01

Traceability, accuracy and consistency of radiation measurements are essential in radiation dosimetry, particularly in radiotherapy, where the outcome of treatments is highly dependent on the radiation dose delivered to patients. The role of Secondary Standard Dosimetry Laboratories (SSDLs) is crucial in providing traceable calibrations to hospitals, since these laboratories disseminate calibrations at specific radiation qualities appropriate to the use of radiation measuring instruments. These laboratories follow IAEA/WHO guidelines for calibration procedures, often being current and charge measurements described in these guidelines a tedious task. However, these measurements are usually done using modern electrometers which are equipped with a RS-232 interface that allows instrument control from a PC. This paper presents the design and employment of an automated system aimed to the measurements of the radiotherapy dosimeters calibration process for Cobalt-60 gamma rays. A software was developed using Lab View, in order to achieve the acquisition of the charge values measured, calculation of the calibration coefficient and issue of a calibration certificate. A primary data report file is filled and stored in the PC's hard disk. By using this software tool, a better control over the calibration process is achieved, it reduces the need for human intervention and it also reduces the exposure of the laboratory staff. The automated system has been used for the calibration of reference dosimeters used in radiotherapy at the Cuban Secondary Standard Dosimetry Laboratory of the Center for Radiation Protection and Hygiene (Author)

The Seibersdorf TL Personnel Dosimetry Service

Energy Technology Data Exchange (ETDEWEB)

Duftschmid, K E [Oesterreichisches Forschungszentrum Seibersdorf GmbH (Austria)

1994-11-01

Since 1976 the Department for Radiation Protection of the Austrian Research Centre Seibersdorf has been operating a TLD Personnel Monitoring Service, which presently covers about 18,000 radiation workers in Austria, with monthly monitoring periods. We have been the first accredited monitoring service in Europe, which fully converted from film dosimetry to TLD. From the beginning up to 1991 the service was based on three automated TLD systems Model 2271 from HARSHAW, USA. After extensive testing and comparisons, since almost four years now, the monitoring service has been operating on two HARSHAW 8800 systems, which are described in more detail below. (author).

The Seibersdorf TL Personnel Dosimetry Service

International Nuclear Information System (INIS)

Duftschmid, K.E.

1994-11-01

Since 1976 the Department for Radiation Protection of the Austrian Research Centre Seibersdorf has been operating a TLD Personnel Monitoring Service, which presently covers about 18,000 radiation workers in Austria, with monthly monitoring periods. We have been the first accredited monitoring service in Europe, which fully converted from film dosimetry to TLD. From the beginning up to 1991 the service was based on three automated TLD systems Model 2271 from HARSHAW, USA. After extensive testing and comparisons, since almost four years now, the monitoring service has been operating on two HARSHAW 8800 systems, which are described in more detail below. (author)

Calibration of helical tomotherapy machine using EPR/alanine dosimetry.

Science.gov (United States)

Perichon, Nicolas; Garcia, Tristan; François, Pascal; Lourenço, Valérie; Lesven, Caroline; Bordy, Jean-Marc

2011-03-01

Current codes of practice for clinical reference dosimetry of high-energy photon beams in conventional radiotherapy recommend using a 10 x 10 cm2 square field, with the detector at a reference depth of 10 cm in water and 100 cm source to surface distance (SSD) (AAPM TG-51) or 100 cm source-to-axis distance (SAD) (IAEA TRS-398). However, the maximum field size of a helical tomotherapy (HT) machine is 40 x 5 cm2 defined at 85 cm SAD. These nonstandard conditions prevent a direct implementation of these protocols. The purpose of this study is twofold: To check the absorbed dose in water and dose rate calibration of a tomotherapy unit as well as the accuracy of the tomotherapy treatment planning system (TPS) calculations for a specific test case. Both topics are based on the use of electron paramagnetic resonance (EPR) using alanine as transfer dosimeter between the Laboratoire National Henri Becquerel (LNHB) 60Co-gamma-ray reference beam and the Institut Curie's HT beam. Irradiations performed in the LNHB reference 60Co-gamma-ray beam allowed setting up the calibration method, which was then implemented and tested at the LNHB 6 MV linac x-ray beam, resulting in a deviation of 1.6% (at a 1% standard uncertainty) relative to the reference value determined with the standard IAEA TRS-398 protocol. HT beam dose rate estimation shows a difference of 2% with the value stated by the manufacturer at a 2% standard uncertainty. A 4% deviation between measured dose and the calculation from the tomotherapy TPS was found. The latter was originated by an inadequate representation of the phantom CT-scan values and, consequently, mass densities within the phantom. This difference has been explained by the mass density values given by the CT-scan and used by the TPS which were not the true ones. Once corrected using Monte Carlo N-Particle simulations to validate the accuracy of this process, the difference between corrected TPS calculations and alanine measured dose values was then

Calibration of farmer dosemeters

International Nuclear Information System (INIS)

Ahmad, S.S.; Anwar, K.; Arshed, W.; Mubarak, M.A.; Orfi, S.D.

1984-08-01

The Farmer Dosemeters of Atomic Energy Medical Centre (AEMC) Jamshoro were calibrated in the Secondary Standard Dosimetry Laboratory (SSDL) at PINSTECH, using the NPL Secondary Standard Therapy level X-ray exposure meter. The results are presented in this report. (authors)

Characterization and Simulation of a New Design Parallel-Plate Ionization Chamber for CT Dosimetry at Calibration Laboratories

Science.gov (United States)

Perini, Ana P.; Neves, Lucio P.; Maia, Ana F.; Caldas, Linda V. E.

2013-12-01

In this work, a new extended-length parallel-plate ionization chamber was tested in the standard radiation qualities for computed tomography established according to the half-value layers defined at the IEC 61267 standard, at the Calibration Laboratory of the Instituto de Pesquisas Energéticas e Nucleares (IPEN). The experimental characterization was made following the IEC 61674 standard recommendations. The experimental results obtained with the ionization chamber studied in this work were compared to those obtained with a commercial pencil ionization chamber, showing a good agreement. With the use of the PENELOPE Monte Carlo code, simulations were undertaken to evaluate the influence of the cables, insulator, PMMA body, collecting electrode, guard ring, screws, as well as different materials and geometrical arrangements, on the energy deposited on the ionization chamber sensitive volume. The maximum influence observed was 13.3% for the collecting electrode, and regarding the use of different materials and design, the substitutions showed that the original project presented the most suitable configuration. The experimental and simulated results obtained in this work show that this ionization chamber has appropriate characteristics to be used at calibration laboratories, for dosimetry in standard computed tomography and diagnostic radiology quality beams.

Performance of a parallel plate ionization chamber in beta radiation dosimetry

International Nuclear Information System (INIS)

Antonio, Patricia L.; Caldas, Linda V.E.

2011-01-01

A homemade parallel plate ionization chamber with graphite collecting electrode, and developed for use in mammography beams, was tested in relation to its usefulness in beta radiation dosimetry at the Calibration Laboratory of IPEN. Characterization tests of this ionization chamber were performed, using the Sr-90 + Y-90, Kr-85 and Pm-147 sources of a beta secondary standard system. The results of saturation, leakage current, stabilization time, response stability, linearity, angular dependence, and calibration coefficients are within the recommended limits of international recommendations that indicate that this chamber may be used for beta radiation dosimetry. (author)

Performance of a parallel plate ionization chamber in beta radiation dosimetry

Energy Technology Data Exchange (ETDEWEB)

Antonio, Patricia L.; Caldas, Linda V.E., E-mail: patrilan@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-07-01

A homemade parallel plate ionization chamber with graphite collecting electrode, and developed for use in mammography beams, was tested in relation to its usefulness in beta radiation dosimetry at the Calibration Laboratory of IPEN. Characterization tests of this ionization chamber were performed, using the Sr-90 + Y-90, Kr-85 and Pm-147 sources of a beta secondary standard system. The results of saturation, leakage current, stabilization time, response stability, linearity, angular dependence, and calibration coefficients are within the recommended limits of international recommendations that indicate that this chamber may be used for beta radiation dosimetry. (author)

75 FR 59605 - National Veterinary Accreditation Program; Currently Accredited Veterinarians Performing...

Science.gov (United States)

2010-09-28

.... APHIS-2006-0093] RIN 0579-AC04 National Veterinary Accreditation Program; Currently Accredited... Veterinary Accreditation Program (NVAP) may continue to perform accredited duties and to elect to continue to..., National Veterinary Accreditation Program, VS, APHIS, 4700 River Road Unit 200, Riverdale, MD 20737; (301...

TH-A-204-01: Part I - Key Data for Ionizing-Radiation Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Seltzer, S. [National Institute of Standards & Technology (United States)

2016-06-15

The ICRU is currently finalizing a report on key data for radiation dosimetry. This multi-year review has resulted in a number of recommendations regarding “fundamental” data that are used in dosimetry related to radiation therapy. This educational session will explain the background for the ICRU committee’s work, the content and conclusions of the report and the impact on outputs, including NIST primary standards, ADCL calibration coefficients and clinical reference dosimetry. Parameters and beam modalities potentially affected by this report include: The mean excitation energy, I, for graphite, air, and water, The average energy required to create an ion pair in dry air (commonly referred to as W/e), The uncertainty in the determination of air kerma in kV x-rays The absolute value of Co-60 and Cs-137 primary standards and the dissemination of calibration coefficients, The determination of air kerma strength for Ir-192 HDR brachytherapy sources Ion chamber kQ factors for linac MV beams Ion chamber kQ factors for proton beams. The changes in reference dosimetry that would result from adoption of the ICRU recommendations are of the order of 0.5% to 1%, an effect that will not impact clinical dose delivery but will be detectable in the clinical setting. This session will also outline how worldwide metrology is coordinated through the Convention of the Meter and therefore how the international dosimetry community will proceed with adopting these recommendations so that uniformity from country to country in reference dosimetry is maintained. Timelines and communications methods will also be discussed to ensure that users, such as clinical medical physicists, are not surprised when their chamber’s calibration coefficient apparently changes. Learning Objectives: Understand the background for the ICRU committee’s work on key dosimetry data. Understand the proposed changes to key data and the impacts on reference dosimetry. Understand the methodology and timeline

TH-A-204-00: Key Dosimetry Data - Impact of New ICRU Recommendations

Energy Technology Data Exchange (ETDEWEB)

NONE

2016-06-15

The ICRU is currently finalizing a report on key data for radiation dosimetry. This multi-year review has resulted in a number of recommendations regarding “fundamental” data that are used in dosimetry related to radiation therapy. This educational session will explain the background for the ICRU committee’s work, the content and conclusions of the report and the impact on outputs, including NIST primary standards, ADCL calibration coefficients and clinical reference dosimetry. Parameters and beam modalities potentially affected by this report include: The mean excitation energy, I, for graphite, air, and water, The average energy required to create an ion pair in dry air (commonly referred to as W/e), The uncertainty in the determination of air kerma in kV xrays The absolute value of Co-60 and Cs-137 primary standards and the dissemination of calibration coefficients, The determination of air kerma strength for Ir-192 HDR brachytherapy sources Ion chamber kQ factors for linac MV beams Ion chamber kQ factors for proton beams. The changes in reference dosimetry that would result from adoption of the ICRU recommendations are of the order of 0.5% to 1%, an effect that will not impact clinical dose delivery but will be detectable in the clinical setting. This session will also outline how worldwide metrology is coordinated through the Convention of the Meter and therefore how the international dosimetry community will proceed with adopting these recommendations so that uniformity from country to country in reference dosimetry is maintained. Timelines and communications methods will also be discussed to ensure that users, such as clinical medical physicists, are not surprised when their chamber’s calibration coefficient apparently changes. Learning Objectives: Understand the background for the ICRU committee’s work on key dosimetry data. Understand the proposed changes to key data and the impacts on reference dosimetry. Understand the methodology and timeline

Organisation of a laboratory of photographic dosimetry

International Nuclear Information System (INIS)

Soudain, Georges

1961-01-01

After a recall of the main properties of photographic dosimetry, the author describes the principle of this method, and comments the issue of chromatic sensitivity of photographic emulsions. He discusses the calibration process for gamma radiation, X rays, and thermal neutrons. He describes how fast neutron dosimetry is performed. In the next part, he describes the organisation of the photometry laboratory which has to prepare and distribute dosimeters, to collect and exploit them, and to prepare a publication of results. These different missions and tasks are described

Lyoluminescence dosimetry of the radiation in industrial doses

International Nuclear Information System (INIS)

Vigna Filho, E. del.

1984-01-01

The γ-rays lyoluminescence (LL) dosimetry study is presented. The basic principles involved, both in the method and radiation dosimetry, the equivalence between water and lyoluminescent materials, apparatus, irradiation technique and calibration method are discussed. The LL response dependence with environmental conditions are presented. These were temperature, humidity, storage time and the dependence on dissolved mass. A pre-reading thermal treatment was developed to overcome previous difficulties. The developed technique was applied to dose intercomparisons. (M.A.C.) [pt

Evaluation of surface contamination based on certifiably traceable, internationally accreditable measurements

International Nuclear Information System (INIS)

Whitlock, G.D.

1992-01-01

National Accreditation and Measurement Service (NAMAS) adopted by the EUROMET agreement requires that the calibration of monitoring instruments be traceable internationally with the objective that radiation hazard assessment be improved. This objective is achieved for Tritium surface contamination by employing calibration sources and evaluation methods which comply with ISO standards including the measurement of activity removable by Volatilization as well as dust. Consideration should be given to organic binding of tritium in the skin with its implications in the event of litigation. (author)

Dosimetry on the radiological risks prevention in radiotherapy

International Nuclear Information System (INIS)

Fornet R, O. M.; Perez G, F.

2014-08-01

Dosimetry in its various forms plays a determining role on the radiological risks prevention in radiotherapy. To prove this in this paper is shown an analysis based on the risk matrix method, how the dosimetry can influence in each stages of a radiotherapy service; installation and acceptance, operation, maintenance and calibration. For each one of these stages the role that can play is analyzed as either the initiating event of a radiological accident or limiting barrier of these events of the dosimetric processes used for the individual dosimetry, the area monitoring, fixed or portable, for radiation beam dosimetry and of the patients for a radiotherapy service with cobalt-therapy equipment. The result of the study shows that the application of a prospective approach in the role evaluation of dosimetry in the prevention and mitigation of the consequences of a radiological accident in radiotherapy is crucial and should be subject to permanent evaluation at each development stage of these services. (author)

Commissioning dosimetry for the laboratory irradiation facility type PX-γ-30

International Nuclear Information System (INIS)

Prieto Miranda, E.F.; Cuesta Fuente, G.I.; Chavez Ardanza, A.; Sainz Vidal, D.

1997-01-01

In the present paper at the laboratory irradiation type PX-y-30 was carried out the commissioning dosimetry, which belongs to Radiological Department of the CEADEN. It was determined the dose distribution as well as principal dosimetric parameters of the irradiation process. Besides, an irradiation position was found for the calibration or intercomparison of dosimetry systems

Personnel neutron dose assessment upgrade: Volume 1, Personnel neutron dosimetry assessment: [Final report

International Nuclear Information System (INIS)

Hadlock, D.E.; Brackenbush, L.W.; Griffith, R.V.; Hankins, D.E.; Parkhurst, M.A.; Stroud, C.M.; Faust, L.G.; Vallario, E.J.

1988-07-01

This report provides guidance on the characteristics, use, and calibration criteria for personnel neutron dosimeters. The report is applicable for neutrons with energies ranging from thermal to less than 20 MeV. Background for general neutron dosimetry requirements is provided, as is relevant federal regulations and other standards. The characteristics of personnel neutron dosimeters are discussed, with particular attention paid to passive neutron dosimetry systems. Two of the systems discussed are used at DOE and DOE-contractor facilities (nuclear track emulsion and thermoluminescent-albedo) and another (the combination TLD/TED) was recently developed. Topics discussed in the field applications of these dosimeters include their theory of operation, their processing, readout, and interpretation, and their advantages and disadvantages for field use. The procedures required for occupational neutron dosimetry are discussed, including radiation monitoring and the wearing of dosimeters, their exchange periods, dose equivalent evaluations, and the documenting of neutron exposures. The coverage of dosimeter testing, maintenance, and calibration includes guidance on the selection of calibration sources, the effects of irradiation geometries, lower limits of detectability, fading, frequency of calibration, spectrometry, and quality control. 49 refs., 6 figs., 8 tabs

5th symposium on neutron dosimetry

Energy Technology Data Exchange (ETDEWEB)

Spurny, F

1985-03-01

The symposium was held in Neuherberg near Munich on September 17-20, 1984 and was attended by 200 specialists from 20 coutries. The participants discussed the following areas of neutron dosimetry: basic concept and analysis of irradiation, basic data, proportional counters in radiation protection, detector response and spectrometry, enviromental monitoring, radiobiology and biophysical models, analysis of neutron fields, thermoluminescent detectors, personnel monitoring, calibration, measurement in the environment of /sup 252/Cf sources, analysis of fields and detector response, standardization dosimetry, ionization chambers, planning of therapeutical irradiation study of depth dose distribution, facilities for neutron therapy and international comparison. (E.S.).

5th symposium on neutron dosimetry

International Nuclear Information System (INIS)

Spurny, F.

1985-01-01

The symposium was held in Neuherberg near Munich on September 17-20, 1984 and was attended by 200 specialists from 20 coutries. The participants discussed the following areas of neutron dosimetry: basic concept and analysis of irradiation, basic data, proportional counters in radiation protection, detector response and spectrometry, enviromental monitoring, radiobiology and biophysical models, analysis of neutron fields, thermoluminescent detectors, personnel monitoring, calibration, measurement in the environment of 252 Cf sources, analysis of fields and detector response, standardization dosimetry, ionization chambers, planning of therapeutical irradiation study of depth dose distribution, facilities for neutron therapy and international comparison. (E.S.)

Activities developed by the biological dosimetry laboratory of the Autoridad Regulatoria Nuclear - ARN of Argentina; Actividades desarrolladas por el laboratorio de dosimetria biologica de la Autoridad Regulatoria Nuclear de Argentina

Energy Technology Data Exchange (ETDEWEB)

Radl, A.; Sapienza, C. E.; Taja, M. R.; Bubniak, R.; Deminge, M.; Di Giorgio, M., E-mail: csapienza@arn.gob.ar [Autoridad Regulatoria Nuclear (ARN), Buenos Aires (Argentina)

2013-07-01

Biological dosimetry (DB) allows to estimate doses absorbed in individuals exposed to ionizing radiation through the quantification of stable and unstable chromosome aberrations (SCA and UCA). The frequency of these aberrations is referred to a calibration dose response curve (in vitro) to determine the doses of the individual to the whole body. The DB is a necessary support for programs of national radiation protection and response systems in nuclear or radiological emergencies in the event of accidental or incidental, single overexposure or large scale. In this context the Laboratory of Dosimetry Biological (LDB) of the Authority Regulatory Nuclear (ARN) Argentina develops and applies different dosimeters cytogenetic from four decades ago. These dosimeters provide a fact more within the whole of the information necessary for an accidental, complementing the physical and clinical dosimetry exposure assessment. The most widely used in the DB biodosimetric method is the quantification of SCA (dicentrics and rings Central) from a sample of venous blood. The LDB is accredited for the trial, under rules IRAM 301: 2005 (ISO / IEC 17025: 2005) and ISO 19238:2004. Test applies to the immediate dosimetry evaluation of acute exposures, all or a large part of the body in the range 0,1-5 Gy. In this context the LDB is part of the Latin American network of DB (LBDNet), BioDoseNet-who and response system in radiological emergencies and nuclear IAEA-RANET, being enabled to summon the LBDNet if necessary.

Comparisons of radiation dosimetry between Louvain (Belgium) and Edinburgh (UK)

International Nuclear Information System (INIS)

Law, J.; Prignot, M.; Wambersie, A.

1975-01-01

A comparison of radiation dosimetry performed between Edinburgh and Louvain using the FeSO 4 system, was reported. The procedure adopted provided comparisons both of solution response and of spectrophotometer calibration, and also provided a comparison of ionization dosimetry and irradiation techniques at the two centres. Therefore dosimeter solutions were prepared in both centres, FeSO 4 samples were irradiated either in Edinburgh (4 MV X-rays) or in Louvain ( 60 Co), finally optical densities were measured using the spectrophotometer of either centre. For these different comparisons, the samples were transported once of twice. An agreement between the two centres better than 1% was observed, both for ionization dosimetry and irradiation techniques and for spectrophotometer calibration. The ratio of Louvain to Edinburgh solution response was found close to 1 (0.998+-0.004). However, a previous comparison showed a discrepancy of 2% which illustrates the care needed in checking the purity of the solution components and mainly of the distilled water

Calibration of dosemeters and survey instruments for photon

International Nuclear Information System (INIS)

Alamares, A.L.; Caseria, E.S.

1995-01-01

The Philippine Nuclear Research Institute (PNRI), the country's regulatory agency, through its Radiation Protection Unit of the Nuclear Regulations Licensing and Safeguard Division provides the calibration services of nuclear instruments used by various institutions. The periodic calibration and standardization of radiation and protection survey instruments are done to insure correct and valid radiation readings. It is also a regulatory requirement for radiation workers to use only operable and precalibrated survey instruments for their work with radioactive materials. The PNRI maintains and operates the Secondary Standard Dosimetry Laboratory (SSDL). It provides the periodic calibration and standardization of radiation monitoring and protection survey instruments, and also the radiological hazard and performance evaluation surveys of radiotherapy facilities and others. For the calibration of survey instruments, the standard sources of Cs-137 and Co-60 are used. The calibration procedures for survey meters and pocket dosimeters are explained. The clients served are shown. The personnel dosimetry using film badges, the application of ICRU operational quantities, and the problems encountered and recommendations are reported. (K.I.)

Development of a quality assurance program for ionizing radiation secondary calibration laboratories

Energy Technology Data Exchange (ETDEWEB)

Heaton, H.T. II; Taylor, A.R. Jr. [Center for Devices and Radiological Health, Rockville, MD (United States)

1993-12-31

For calibration laboratories, routine calibrations of instruments meeting stated accuracy goals are important. One method of achieving the accuracy goals is to establish and follow a quality assurance program designed to monitor all aspects of the calibration program and to provide the appropriate feedback mechanism if adjustments are needed. In the United States there are a number of organizations with laboratory accreditation programs. All existing accreditation programs require that the laboratory implement a quality assurance program with essentially the same elements in all of these programs. Collectively, these elements have been designated as a Measurement Quality Assurance (MQA) program. This paper will briefly discuss the interrelationship of the elements of an MQA program. Using the Center for Devices and Radiological Health (CDRH) X-ray Calibration Laboratory (XCL) as an example, it will focus on setting up a quality control program for the equipment in a Secondary Calibration Laboratory.

Development of a quality assurance program for ionizing radiation secondary calibration laboratories

International Nuclear Information System (INIS)

Heaton, H.T. II; Taylor, A.R. Jr.

1993-01-01

For calibration laboratories, routine calibrations of instruments meeting stated accuracy goals are important. One method of achieving the accuracy goals is to establish and follow a quality assurance program designed to monitor all aspects of the calibration program and to provide the appropriate feedback mechanism if adjustments are needed. In the United States there are a number of organizations with laboratory accreditation programs. All existing accreditation programs require that the laboratory implement a quality assurance program with essentially the same elements in all of these programs. Collectively, these elements have been designated as a Measurement Quality Assurance (MQA) program. This paper will briefly discuss the interrelationship of the elements of an MQA program. Using the Center for Devices and Radiological Health (CDRH) X-ray Calibration Laboratory (XCL) as an example, it will focus on setting up a quality control program for the equipment in a Secondary Calibration Laboratory

A dosimetry study comparing NCS report-5, IAEA TRS-381, AAPM TG-51 and IAEA TRS-398 in three clinical electron beam energies

International Nuclear Information System (INIS)

Palmans, Hugo; Nafaa, Laila; Patoul, Nathalie de; Denis, Jean-Marc; Tomsej, Milan; Vynckier, Stefaan

2003-01-01

New codes of practice for reference dosimetry in clinical high-energy photon and electron beams have been published recently, to replace the air kerma based codes of practice that have determined the dosimetry of these beams for the past twenty years. In the present work, we compared dosimetry based on the two most widespread absorbed dose based recommendations (AAPM TG-51 and IAEA TRS-398) with two air kerma based recommendations (NCS report-5 and IAEA TRS-381). Measurements were performed in three clinical electron beam energies using two NE2571-type cylindrical chambers, two Markus-type plane-parallel chambers and two NACP-02-type plane-parallel chambers. Dosimetry based on direct calibrations of all chambers in 60 Co was investigated, as well as dosimetry based on cross-calibrations of plane-parallel chambers against a cylindrical chamber in a high-energy electron beam. Furthermore, 60 Co perturbation factors for plane-parallel chambers were derived. It is shown that the use of 60 Co calibration factors could result in deviations of more than 2% for plane-parallel chambers between the old and new codes of practice, whereas the use of cross-calibration factors, which is the first recommendation in the new codes, reduces the differences to less than 0.8% for all situations investigated here. The results thus show that neither the chamber-to-chamber variations, nor the obtained absolute dose values are significantly altered by changing from air kerma based dosimetry to absorbed dose based dosimetry when using calibration factors obtained from the Laboratory for Standard Dosimetry, Ghent, Belgium. The values of the 60 Co perturbation factor for plane-parallel chambers (k att · k m for the air kerma based and p wall for the absorbed based codes of practice) that are obtained from comparing the results based on 60 Co calibrations and cross-calibrations are within the experimental uncertainties in agreement with the results from other investigators

An on-site dosimetry audit for high-energy electron beams

Directory of Open Access Journals (Sweden)

Leon de Prez

2018-01-01

Full Text Available Background and purpose: External dosimetry audits are powerful quality assurance instruments for radiotherapy. The aim of this study was to implement an electron dosimetry audit based on a contemporary code of practice within the requirements for calibration laboratories performing proficiency tests. This involved the determination of suitable acceptance criteria based on thorough uncertainty analyses. Materials and methods: Subject of the audit was the determination of absorbed dose to water, Dw, and the beam quality specifier, R50,dos. Fifteen electron beams were measured in four institutes according to the Belgian-Dutch code of practice for high-energy electron beams. The expanded uncertainty (k = 2 for the Dw values was 3.6% for a Roos chamber calibrated in 60Co and 3.2% for a Roos chamber cross-calibrated against a Farmer chamber. The expanded uncertainty for the beam quality specifier, R50,dos, was 0.14 cm. The audit acceptance levels were based on the expanded uncertainties for the comparison results and estimated to be 2.4%. Results: The audit was implemented and validated successfully. All Dw audit results were satisfactory with differences in Dw values mostly smaller than 0.5% and always smaller than 1%. Except for one, differences in R50,dos were smaller than 0.2 cm and always smaller than 0.3 cm. Conclusions: An electron dosimetry audit based on absorbed dose to water and present-day requirements for calibration laboratories performing proficiency tests was successfully implemented. It proved international traceability of the participants value with an uncertainty better than 3.6% (k = 2. Keywords: Absorbed dose to water, Audit, Code of practice, Dosimetry, Electron beam, Radiation therapy

Electromedical devices test laboratories accreditation

International Nuclear Information System (INIS)

Murad, C; Rubio, D; Ponce, S; Alvarez Abri, A; Terron, A; Vicencio, D; Fascioli, E

2007-01-01

In the last years, the technology and equipment at hospitals have been increase in a great way as the risks of their implementation. Safety in medical equipment must be considered an important issue to protect patients and their users. For this reason, test and calibrations laboratories must verify the correct performance of this kind of devices under national and international standards. Is an essential mission for laboratories to develop their measurement activities taking into account a quality management system. In this article, we intend to transmit our experience working to achieve an accredited Test Laboratories for medical devices in National technological University

Radiation Calibration Measurements

International Nuclear Information System (INIS)

Omondi, C.

2017-01-01

KEBS Radiation Dosimetry mandate are: Custodian of Kenya Standards on Ionizing radiation, Ensure traceability to International System (SI ) and Calibration radiation equipment. RAF 8/040 on Radioisotope applications for troubleshooting and optimizing industrial process established Radiotracer Laboratory objective is to introduce and implement radiotracer technique for problem solving of industrial challenges. Gamma ray scanning technique applied is to Locate blockages, Locate liquid in vapor lines, Locate areas of lost refractory or lining in a pipe and Measure flowing densities. Equipment used for diagnostic and radiation protection must be calibrated to ensure Accuracy and Traceability

Accredited Birth Centers

Science.gov (United States)

... Danbury, CT 06810 203-748-6000 Accredited Since March 1998 Corvallis Birth & Women's Health Center Accredited 2314 NW Kings Blvd, Suite ... Washington, DC 20002 202-398-5520 Accredited Since March 2001 Flagstaff Birth and Women's Center Accredited 401 West Aspen Avenue Flagstaff, AZ ...

Hanford External Dosimetry Technical Basis Manual PNL-MA-842

Energy Technology Data Exchange (ETDEWEB)

Rathbone, Bruce A.

2010-04-01

The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at the U.S. Department of Energy (DOE) Hanford site. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with requirements of 10 CFR 835, the DOE Laboratory Accreditation Program, the DOE Richland Operations Office, DOE Office of River Protection, DOE Pacific Northwest Office of Science, and Hanford’s DOE contractors. The dosimetry system is operated by the Pacific Northwest National Laboratory (PNNL) Hanford External Dosimetry Program which provides dosimetry services to PNNL and all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since its inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. The first revision to be released through PNNL’s Electronic Records & Information Capture Architecture database was designated Revision 0. Revision numbers that are whole numbers reflect major revisions typically involving significant changes to all chapters in the document. Revision

Hanford External Dosimetry Technical Basis Manual PNL-MA-842

Energy Technology Data Exchange (ETDEWEB)

Rathbone, Bruce A.

2011-04-04

The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at the U.S. Department of Energy (DOE) Hanford site. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with requirements of 10 CFR 835, the DOE Laboratory Accreditation Program, the DOE Richland Operations Office, DOE Office of River Protection, DOE Pacific Northwest Office of Science, and Hanford’s DOE contractors. The dosimetry system is operated by the Pacific Northwest National Laboratory (PNNL) Hanford External Dosimetry Program which provides dosimetry services to PNNL and all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since its inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. The first revision to be released through PNNL’s Electronic Records & Information Capture Architecture database was designated Revision 0. Revision numbers that are whole numbers reflect major revisions typically involving significant changes to all chapters in the document. Revision

Calibration of ratemeters used for gamma radiation detection

International Nuclear Information System (INIS)

Hantanirina, P.A.

2017-01-01

The Secondary Standard Dosimetry Laboratory (SSDL) of INSTN-Madagascar is in charge of the calibration of every dosimetry measurement instrument in hospitals and companies using radioactive sources in Madagascar. It has a secondary standard delivered and calibrated by a Primary Standard Laboratory in Dosimetry (PSLD). This standard is used to compare its reference values with those displayed on the instruments to be calibrated. During our training period, three (3) ratemeters were calibrated, the Graetz X5DE, the Graetz X5C and the Identifinder 2. We have determined the calibration factor for every ratemeter by doing calculation with the reference value. By using the three surveymeters for direct radiations measurements, it has been found that the difference between the displayed values and the real values for every ratemeter does not exceed the tolerance limit which is 20 %. Then we can conclude that these ratemeters are still in good condition of functioning. Concerning the calibration factor curve N_k with the K_a_i_r , we can observe that for the Graetz X5C ratemeter, this curve is almost constant. As well as for the linearity, it is still the Graetz X5C ratemeter which is linear almost integrally for the measured and calculated dose rate values. So we can say that this ratemeter is the most recommended for the radiations measurements.This work which has been carried within the framework of collaboration between the section PNAE (Physique Nucléaire Appliquée et Environnement) of the University of Antananarivo and INSTN-Madagascar has been a good and rewarding experience which allowed us to put into practice all knowledges acquired during our years of studies. [fr

Dosimetry in diagnostic and interventional radiology - ICRU and IAEA activities

International Nuclear Information System (INIS)

Zoetelief, J.; Pernicka, F.

2002-01-01

Full text: Main aims of patient dosimetry in diagnostic and interventional radiology are to determine dosimetric quantities for establishment and use of guidance levels or diagnostic reference levels and for comparative risk assessment. In the latter case, the average doses to the organs and tissues at risk should be assessed. Only limited number of measurements serve to potential risk assessment of the examination and intervention. An additional objective of dosimetry in diagnostic and interventional radiology is the assessment of equipment performance. Ionization chambers are the main devices used for dosimetric measurements in diagnostic and interventional radiology but other devices with special properties are also used. Important examples are thermoluminescent detectors (TLDs) and semiconductor detectors. For most dosemeters used in x-ray medical imaging the desired quantity for calibration of dosemeters is the air kerma free-in-air. Calibrations should be made at appropriate radiation qualities, for which recommendations are available for conventional radiology. It is important that the calibrations are traceable to the international measurement system. The uncertainty of dose measurements in medical x-ray imaging, for comparative risk assessments as well as for quality assurance, should not exceed about 7 per cent in terms of the expanded uncertainty using a coverage factor of 2. The dosimetric approaches in general diagnostic radiology, mammography and computed tomography are slightly different, resulting in application specific dosimetric quantities. Consequently, different protocols for patient dosimetry are available for these different purposes. In general diagnostic radiology, various quantities and terminologies have been used for the specification of dose on the central beam axis at the point where the x-ray beam enters the patient (or a phantom representing the patient). These include the exposure at skin entrance (ESE), the input radiation exposure

Improvement of the WBC calibration of the Internal Dosimetry Laboratory of the CDTN/CNEN using MCNPX code

Energy Technology Data Exchange (ETDEWEB)

Guerra P, F.; Heeren de O, A. [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Programa de Pos Graduacao em Ciencias e Tecnicas Nucleares, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Melo, B. M.; Lacerda, M. A. S.; Da Silva, T. A.; Ferreira F, T. C., E-mail: tcff01@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear, Programa de Pos Graduacao / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

2015-10-15

The Plan of Radiological Protection licensed by the National Nuclear Energy Commission - CNEN in Brazil includes the risks of assessment of internal and external exposure by implementing a program of individual monitoring which is responsible of controlling exposures and ensuring the maintenance of radiation safety. The Laboratory of Internal Dosimetry of the Center for Development of Nuclear Technology - LID/CDTN is responsible for routine monitoring of internal contamination of the Individuals Occupationally Exposed (IOEs). These are, the IOEs involved in handling {sup 18}F produced by the Unit for Research and Production of Radiopharmaceuticals sources; as well a monitoring of the entire body of workers from the Research Reactor TRIGA IPR-R1/CDTN or whenever there is any risk of accidental incorporation. The determination of photon emitting radionuclides from the human body requires calibration techniques of the counting geometries, in order to obtain a curve of efficiency. The calibration process normally makes use of physical phantoms containing certified activities of the radionuclides of interest. The objective of this project is the calibration of the WBC facility of the LID/CDTN using the BOMAB physical phantom and Monte Carlo simulations. Three steps were needed to complete the calibration process. First, the BOMAB was filled with a KCl solution and several measurements of the gamma ray energy (1.46 MeV) emitted by {sup 40}K were done. Second, simulations using MCNPX code were performed to calculate the counting efficiency (Ce) for the BOMAB model phantom and compared with the measurements Ce results. Third and last step, the modeled BOMAB phantom was used to calculate the Ce covering the energy range of interest. The results showed a good agreement and are within the expected ratio between the measured and simulated results. (Author)

Improvement of the WBC calibration of the Internal Dosimetry Laboratory of the CDTN/CNEN using MCNPX code

International Nuclear Information System (INIS)

Guerra P, F.; Heeren de O, A.; Melo, B. M.; Lacerda, M. A. S.; Da Silva, T. A.; Ferreira F, T. C.

2015-10-01

The Plan of Radiological Protection licensed by the National Nuclear Energy Commission - CNEN in Brazil includes the risks of assessment of internal and external exposure by implementing a program of individual monitoring which is responsible of controlling exposures and ensuring the maintenance of radiation safety. The Laboratory of Internal Dosimetry of the Center for Development of Nuclear Technology - LID/CDTN is responsible for routine monitoring of internal contamination of the Individuals Occupationally Exposed (IOEs). These are, the IOEs involved in handling 18 F produced by the Unit for Research and Production of Radiopharmaceuticals sources; as well a monitoring of the entire body of workers from the Research Reactor TRIGA IPR-R1/CDTN or whenever there is any risk of accidental incorporation. The determination of photon emitting radionuclides from the human body requires calibration techniques of the counting geometries, in order to obtain a curve of efficiency. The calibration process normally makes use of physical phantoms containing certified activities of the radionuclides of interest. The objective of this project is the calibration of the WBC facility of the LID/CDTN using the BOMAB physical phantom and Monte Carlo simulations. Three steps were needed to complete the calibration process. First, the BOMAB was filled with a KCl solution and several measurements of the gamma ray energy (1.46 MeV) emitted by 40 K were done. Second, simulations using MCNPX code were performed to calculate the counting efficiency (Ce) for the BOMAB model phantom and compared with the measurements Ce results. Third and last step, the modeled BOMAB phantom was used to calculate the Ce covering the energy range of interest. The results showed a good agreement and are within the expected ratio between the measured and simulated results. (Author)

Calibration of nuclear medicine gamma counters

International Nuclear Information System (INIS)

Orlic, M.; Spasic-Jokic, V.; Jovanovic, M.; Vranjes, S. . E-mail address of corresponding author: morlic@vin.bg.ac.yu; Orlic, M.)

2005-01-01

In this paper the practical problem of nuclear medicine gamma counters calibration has been solved by using dose calibrators CRC-15R with standard error ±5%. The samples from technetium generators have been measured both by dose calibrators CRC-15R and gamma counter ICN Gamma 3.33 taking into account decay correction. Only the linear part of the curve has practical meaning. The advantage of this procedure satisfies the requirements from international standards: the calibration of sources used for medical exposure be traceable to a standard dosimetry laboratory and radiopharmaceuticals for nuclear medicine procedures be calibrated in terms of activity of the radiopharmaceutical to be administered. (author)

Clinical electron beam dosimetry: transition from AAPM TG-25 to AAPM TG-70

International Nuclear Information System (INIS)

Mihailidis, Dimitris

2017-01-01

The absolute calibration of clinical electron beams is increasingly based on TG-51 protocol. In addition, recently published dosimetry data on electrons beams bring up the question of how would one need to modify the widely used TG-25 that originally was based on TG-21 calibration protocol? The answer to the question is given by the recently published TG-70. This new protocol operates as supplement and update to TG-25 on issues that need to be modified because of TG-51 approach to electron dosimetry and because of newer data on clinical electron beams. It describes in detail the procedure of converting measured depth-ionization curves with ion chambers into depth-dose curves, making use of recently published stopping-power ratios and other conversion factors. It also describes the use of water equivalent phantoms to perform relative electron dosimetry based on recently published conversions factors. The report discusses small and irregularly shaped electron field dosimetry using the concept of lateral buildup ratio (LBR) as an avenue to evaluate electronic equilibrium and compute dose per MU for those fields. Finally, it gives some common clinical examples where electron beam dosimetry are applied

Factors influencing EPR dosimetry in fingernails

International Nuclear Information System (INIS)

Dubner, D.L.; Spinella, M.R.; Bof, E.

2010-01-01

The technique based on the detection of ionizing radiation induced radicals by EPR in tooth enamel is an established method for the dosimetry of exposed persons in radiological emergencies. Dosimetry based on EPR spectral analysis of fingernail clippings, currently under development, has the practical advantage of the easier sample collection. A limiting factor is that overlapping the radiation induced signal (RIS), fingernails have shown the presence of two mechanically induced signals, called MIS1 and MIS2, due to elastic and plastic deformation respectively, at the time of fingernails cutting. With a water treatment, MIS1 is eliminated while MIS2 is considerably reduced. The calibration curves needed for radiation accident dosimetry should have 'universal' characteristics, ie. Represent the variability that can be found in different individuals. Early studies were directed to the analysis of factors affecting the development of such universal calibration curves. The peak to peak amplitude of the signal before and after the water treatment as well as the effect of size and number of clippings were studied. Furthermore, the interpersonal and intrapersonal variability were analyzed. Taking into account these previous studies, the optimal conditions for measurement were determined and EPR spectra of samples irradiated at different doses were used for the developing of dose-response curves. This paper presents the analysis of the results.(authors) [es

Accredition: An accredited utility's perspective

International Nuclear Information System (INIS)

Jambrovic, H.

1990-01-01

Accredition is a quality assurance program that applies to electricity billing meters. Under the Electricity and Gas Inspection Act, an electricity meter is not a legal billing device until a prototype has been scrutinized and approved for use by Consumer and Corporate Affairs Canada (CCAC) laboratories, and a meter cannot be used for billing purposes unless its accuracy and condition have been inspected and the meter is sealed to prevent tampering. In 1986 an ammendment to the act allowed accredited organizations to inspect, verify and seal their own billing meters. Ontario Hydro embarked on a program to become accredited in 1987, to offset spiraling government inspection fees in the order of $500,000/y, and to be less dependent on the availability of government inspectors. Ontario Hydro achieved accredition status two years after embarking on the program, which involved completion of cost benefit analysis, securing senior management commitment, preparation of a comprehensive quality assurance program manual, implementation of quality assurance program policies, procedures and controls, submitting meter shop operations and field meter handling practices to both internal Ontario Hydro and external government audit, and correction of audit findings. 2 figs

A new method for dosimetry with films radiochromic; Un nuevo metodo para la dosimetria con peliculas radiocromica

Energy Technology Data Exchange (ETDEWEB)

Mendez Carot, I.

2013-07-01

in this paper a new method is presented and the results of the comparison between the calibration is summarized based on a planning reference and calibration obtained from the irradiated fragments measure different dose levels multichannel compare dosimetry based on the weighted average dosimetry described by Micke et al.(present in the FilmQAPro software) and, finally, show different results obtained with the method proposed in several applications clinics. (Author)

Accreditation and training on internal dosimetry in a laboratory network in Brazil: an increasing demand.

Science.gov (United States)

Dantas, B M; Dantas, A L A; Acar, M E D; Cardoso, J C S; Julião, L M Q C; Lima, M F; Taddei, M H T; Arine, D R; Alonso, T; Ramos, M A P; Fajgelj, A

2011-03-01

In recent years, Brazilian Nuclear Programme has been reviewed and updated by government authorities in face of the demand for energy supply and its associated environmental constraints. The immediate impact of new national programmes and projects in nuclear field is the increase in the number of exposed personnel and the consequent need for reliable dosimetry services in the country. Several Technical Documents related to internal dosimetry have been released by the International Atomic Energy Agency and International Commission on Radiological Protection. However, standard bioassay procedures and methodologies for bioassay data interpretation are still under discussion and, in some cases, both in routine and emergency internal monitoring, procedures can vary from one laboratory to another and responses may differ markedly among Dosimetry Laboratories. Thus, it may be difficult to interpret and use bioassay data generated from different laboratories of a network. The main goal of this work is to implement a National Network of Laboratories aimed to provide reliable internal monitoring services in Brazil. The establishment of harmonised in vivo and in vitro radioanalytical techniques, dose assessment methods and the implementation of the ISO/IEC 17025 requirements will result in the recognition of technical competence of the network.

Comparison between IAEA/TRS-277 and IAEA/TRS-398 protocols for electron beam dosimetry with cylindrical ionization chambers

International Nuclear Information System (INIS)

Souza, Roberto Salomon de

2004-01-01

With the purpose to guarantee an uncertainty in the dosimetry in radiation therapy, the International Atomic Energy Agency (IAEA) published in 1987 the Technical Reports Series (TRS) number 277 - Absorbed Dose Determination in Photon and Electron Beams - An International Code of Practice -, updated in 1997, when was published its second edition. In 2000 was published the TRS number 398 - Absorbed Dose Determination in External Beam Radiotherapy - An International Code of Practice for Dosimetry Based on Standards of Absorbed Dose to Water. The TRS number 398 brings a great conceptual change in relation to the basis of the formalism, before based on calibration factor in terms of air kerma, and now based on calibration factor in terms of absorbed dose in water. Since the TRS number 398 was published, the Secondary Standard Dosimetry Laboratories are calibrating the user's ionization chambers in terms of absorbed dose to water. However, nor all the clinics in Rio de Janeiro and Brazil have its ionization chambers calibrated in terms of absorbed dose to water. The National Cancer Institute, where the measurements were taken, was the first institution in the Rio de Janeiro to have its ionization chambers calibrated in terms of a new formalism. This work describes a comparison between dosimetry done with a cylindrical ionization chamber under electron beams utilizing the TRS number 277 formalism, based on air kerma, and the TRS number 398 formalism, based on absorbed dose to water, reporting the uncertainties variation of the dosimetry associated to each protocol. (author)

First Interlaboratory Comparison on Calibration of Temperature-Controlled Enclosures in Turkey

Science.gov (United States)

Uytun, A.; Kalemci, M.

2017-11-01

The number of accredited laboratories in the field of calibration of temperature-controlled enclosures has been increasing in Turkey. One of the main criteria demonstrating the competence of a calibration laboratory is successful participation in interlaboratory comparisons. Therefore, TUBITAK UME Temperature Laboratory organized the first interlaboratory comparison on "Calibration of Temperature-Controlled Enclosures" in Turkey as a pilot laboratory between January and November, 2013. Forty accredited laboratories which provide routine calibration services to the industry in this field participated in the comparison. The standards used during the comparison was a climatic chamber for the measurements at -40 {°}C, -20 {°}C, 40 {°}C and 100 {°}C and an oven for the measurements at 200 {°}C. The protocol of the comparison was prepared considering guide EURAMET cg-20 and BS EN/IEC standards 600068-3-5 and 600068-3-11. During the comparison measurements, each participant had the liberty to choose the most convenient calibration points in terms of their accreditation scope among the values mentioned above and carried out on-site measurements at UME. The details and the results of this comparison are given in the paper. Determination of the statistical consistency of the results with the uncertainties given by the participants can be assessed by the method of En value assessment for each laboratory. En values for all measurement results based on the results of pilot and participating laboratories were calculated.

Status of computed tomography dosimetry for wide cone beam scanners

International Nuclear Information System (INIS)

2011-01-01

International standardization in dosimetry is essential for the successful exploitation of radiation technology. To provide such standardization in diagnostic radiology, the IAEA published Code of Practice entitled Dosimetry in Diagnostic Radiology: An International Code of Practice (IAEA Technical Reports Series No. 457; 2007), which recommends procedures for calibration and dosimetric measurement both in standards dosimetry laboratories, especially Secondary Standards Dosimetry Laboratories (SSDLs), and in clinical centres for radiology, as found in most hospitals. These standards address the main dosimetric methodologies needed in clinical diagnostic radiology, with the calibration of associated dosimetric equipment, including the measurement methodologies for computed tomography (CT). For some time now there has been a growing awareness that radiation dose originating from medical diagnostic procedures in radiology, is contributing an increasing proportion to the total population dose, with a large component coming from CT examinations. This is accompanied by rapid developments in CT technology, including the use of increasingly wide X ray scanning beams, which are presenting problems in dosimetry that currently cannot be adequately addressed by existing standards. This situation has received attention from a number of professional bodies, and institutions have proposed and are investigating new and adapted dosimetric models in order to find robust solutions to these problems that are critically affecting clinical application of CT dosimetry. In view of these concerns, and as a response to a recommendation from a coordinated research project that reviewed the implementation of IAEA Technical Reports Series No. 457, a meeting was held to review current dosimetric methodologies and to determine if a practical solution for dosimetry for wide X ray beam CT scanners was currently available. The meeting rapidly formed the view that there was an interim solution that

NIST high-dose calibration services

International Nuclear Information System (INIS)

Humphreys, J.C.

1989-01-01

There is a need for the standardization of high-dose measurements used in the radiation-processing industry in order to provide assured traceability to national standards. NIST provides dosimetry calibration services to this industry. One of these services involves administration of known absorbed doses of gamma rays to customer-supplied dosimeters. The dosimeters are packaged to provide electron equilibrium conditions and are irradiated in a standard 60 Co calibration facility; this provides a calibration of that batch of dosimeters. Another service consists of supplying to a customer calibrated transfer dosimeters for irradiation with the customer's radiation source. The irradiated transfer dosimeters are then returned to NIST for analysis; the results are reported to the customer, providing a calibration of the dose rate of the customer's source. (orig.)

Dosimetry standards for radiation processing

International Nuclear Information System (INIS)

Farrar, H. IV

1999-01-01

For irradiation treatments to be reproducible in the laboratory and then in the commercial environment, and for products to have certified absorbed doses, standardized dosimetry techniques are needed. This need is being satisfied by standards being developed by experts from around the world under the auspices of Subcommittee E10.01 of the American Society for Testing and Materials (ASTM). In the time period since it was formed in 1984, the subcommittee has grown to 150 members from 43 countries, representing a broad cross-section of industry, government and university interests. With cooperation from other international organizations, it has taken the combined part-time effort of all these people more than 13 years to complete 24 dosimetry standards. Four are specifically for food irradiation or agricultural applications, but the majority apply to all forms of gamma, x-ray, Bremsstrahlung and electron beam radiation processing, including dosimetry for sterilization of health care products and the radiation processing of fruits, vegetables, meats, spices, processed foods, plastics, inks, medical wastes and paper. An additional 6 standards are under development. Most of the standards provide exact procedures for using individual dosimetry systems or for characterizing various types of irradiation facilities, but one covers the selection and calibration of dosimetry systems, and another covers the treatment of uncertainties. Together, this set of standards covers essentially all aspects of dosimetry for radiation processing. The first 20 of these standards have been adopted in their present form by the International Organization of Standardization (ISO), and will be published by ISO in 1999. (author)

The need for international standardization in clinical beta dosimetry for brachytherapy

International Nuclear Information System (INIS)

Quast, U.; Boehm, J.; Kaulich, T.W.

2002-01-01

Beta radiation has found increasing interest in radiotherapy. Besides the curative treatment of small and medium-sized intraocular tumors by means of ophthalmic beta radiation plaques, intravascular brachytherapy has proven to successfully overcome the severe problem of restenosis after interventional treatment of arterial stenosis in coronaries and peripheral vessels in many clinical trials with a large number of patients. Prior to initiating procedures applying beta radiation in radiotherapy, however, there is a common need to specify methods for the determination and specification of the absorbed dose to water or tissue and their spatial distributions. The IAEA-TECDOC-1274 Calibration of photon and beta ray sources used in brachytherapy (2002) is a help for photon brachytherapy calibration. But, for beta seed and line sources, IAEA recommends well type ionization chambers as working standards which are far from measuring absorbed dose to water of the radiation clinically used. Although the application of such working standards seems to be more precise, large errors can occur when the medical physicist has to convert the calibration data to absorbed dose to water of the beta radiation emitted. The user must believe that the source is equally activated and that the manufacturer did not change the design and construction of the source encapsulation. With the DGMP Report 16 (2001) Guidelines for medical physical aspects of intravascular brachytherapy a very detailed code of practice is given, especially for the calibration and clinical dosimetry of intravascular beta radiation sources. As there is a global need for standardization in clinical dosimetry for intravascular brachytherapy utilizing beta radiation, the DIN-NAR, the German committee on standardization in radiology, task group dosimetry, has initiated an international adhoc working group for a new ISO work item proposal on the standardization of procedures in clinical dosimetry to guarantee reliable

Calibration of photon and beta ray sources used in brachytherapy. Guidelines on standardized procedures at Secondary Standards Dosimetry Laboratories; Calibracion de fuentes de fotones y rayos beta usadas en braquiterapia. Guia de procedimiento estandarizados en Laboratorios Secundarios de Calibracion Dosimetrica (LSCD) y en hospitales

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-03-01

It has generally been recognized that international harmonization in radiotherapy dosimetry is essential. Consequently, the IAEA has given much effort to this, for example by publishing a number of reports in the Technical Reports Series (TRS) for external beam dosimetry, most notably TRS-277 and more recently TRS-398. Both of these reports describe in detail the steps to be taken for absorbed dose determination in water and they are often referred to as 'dosimetry protocols'. Similar to TRS-277, it is expected that TRS-398 will be adopted or used as a model by a large number of countries as their national protocol. In 1996, the IAEA established a calibration service for low dose rate (LDR) 137 Cs brachytherapy sources, which is the most widely used source for treatment of gynecological cancer. To further enhance harmonization in brachytherapy dosimetry, the IAEA published in 1999 IAEA-TECDOC-1079 entitled 'Calibration of Brachytherapy Sources. Guidelines on Standardized Procedures for the Calibration of Brachytherapy Sources at Secondary Standard Dosimetry Laboratories (SSDLs) and Hospitals'. The report was well received and was distributed in a large number of copies to the members of the IAEA/WHO network of SSDLs and to medical physicists working with brachytherapy. The present report is an update of the aforementioned TECDOC. Whereas TECDOC-1079 described methods for calibrating brachytherapy sources with photon energies at or above those of {sup 192}Ir, the current report has a wider scope in that it deals with standardization of calibration of all the most commonly used brachytherapy sources, including both photon and beta emitting sources. The latter sources have been in use for a few decades already, but their calibration methods have been unclear. Methods are also described for calibrating sources used in the rapidly growing field of cardiovascular angioplasty. In this application, irradiation of the vessel wall is done in an attempt to prevent restenosis

Calibration of high-dose radiation facilities (Handbook)

International Nuclear Information System (INIS)

Gupta, B.L.; Bhat, R.M.

1986-01-01

In India at present several high intensity radiation sources are used. There are 135 teletheraphy machines and 65 high intensity cobalt-60 sources in the form of gamma chambers (2.5 Ci) and PANBIT (50 Ci). Several food irradiation facilities and a medical sterilization plant ISOMED are also in operation. The application of these high intensity sources involve a wide variation of dose from 10 Gy to 100 kGy. Accurate and reproducible radiation dosimetry is essential in the use of these sources. This handbook is especially compiled for calibration of high-dose radiation facilities. The first few chapters discuss such topics as interaction of radiation with matter, radiation chemistry, radiation processing, commonly used high intensity radiation sources and their special features, radiation units and dosimetry principles. In the chapters which follow, chemical dosimeters are discussed in detail. This discussion covers Fricke dosimeter, FBX dosimeter, ceric sulphate dosimeter, free radical dosimetry, coloured indicators for irrdiation verification. A final chapter is devoted to practical hints to be followed in calibration work. (author)

Dosimetry and process control for radiation processing

International Nuclear Information System (INIS)

Mod Ali, N.

2002-01-01

Complete text of publication follows. Accurate radiation dosimetry can provide quality assurance in radiation processing. Considerable relevant experiences in dosimetry by the SSDL-MINT has necessitate the development of methods making measurement at gamma plant traceable to the national standard. It involves the establishment of proper calibration procedure and selection of appropriate transfer system/technique to assure adequate traceability to a primary radiation standard. The effort forms the basis for irradiation process control, the legal approval of the process by the public health authorities (medical product sterilization and food preservation) and the safety and acceptance of the product

Working conditions analysis according T.L. personal dosimetry results

International Nuclear Information System (INIS)

Marinkovic, O.; Jovanovic, S.

2006-01-01

Laboratory for personal dosimetry in the Institute of Occupational and Radiological Health, Belgrade, used TLD more than twenty years. Before that, film dosimetry was main method in external monitoring. T.L. dosimetry was started with Reader Toledo 654 and crystals Mg B 4 O 7 . Finally, from 1992 laboratory has Harshaw TLD Reader Model 6600. Dosimeters are crystals LiF type 100, card packed, worn in standard filtrated holders. Personal dosimetry data are keeping 30 years for each worker according to regulations. The data from 1990 are in electronic form. Long experience enables conclusion that new technique means more advantages in practice. Recommendation from this laboratory practice refers to TLD read-out cycle. The longest period should be one month. LiF is recommended crystal. Glow curve deconvolution gives information about chronological irradiation. It is very important to conclude was dosimetry irradiated by 'one-shot' or continuously. Preparing calibration for determination the time since accident laboratory has to define adequate dose calibration methodology including low temperature peaks. Possibility to follow working conditions analyzing TLD glow curve is much more important than low decrease of dose severity. Time depend analyze is not possible if TLD would be read-out more than (approximately) six weeks after irradiation. If ionizing sources produce such low dose and has negligible probability of accidental exposure (according nowadays regulation read-out frequency could be once in three month), the recommendation is not to use external personal monitoring. Reading personal dosimeters once in three months deemed not useful. Complete and successful personal dosimetry dictates using system that enables glow curve shape representation to be sure that signal is ionizing irradiation result or not. Time depend analyze imparts information about protection permanence. In special circumstance, it is possible to estimate the time of exposure. This is extremely

Calibration of RB reactor power

International Nuclear Information System (INIS)

Sotic, O.; Markovic, H.; Ninkovic, M.; Strugar, P.; Dimitrijevic, Z.; Takac, S.; Stefanovic, D.; Kocic, A.; Vranic, S.

1976-09-01

The first and only calibration of RB reactor power was done in 1962, and the obtained calibration ratio was used irrespective of the lattice pitch and core configuration. Since the RB reactor is being prepared for operation at higher power levels it was indispensable to reexamine the calibration ratio, estimate its dependence on the lattice pitch, critical level of heavy water and thickness of the side reflector. It was necessary to verify the reliability of control and dosimetry instruments, and establish neutron and gamma dose dependence on reactor power. Two series of experiments were done in June 1976. First series was devoted to tests of control and dosimetry instrumentation and measurements of radiation in the RB reactor building dependent on reactor power. Second series covered measurement of thermal and epithermal neuron fluxes in the reactor core and calculation of reactor power. Four different reactor cores were chosen for these experiments. Reactor pitches were 8, 8√2, and 16 cm with 40, 52 and 82 fuel channels containing 2% enriched fuel. Obtained results and analysis of these results are presented in this document with conclusions related to reactor safe operation

Development of 3D Slicer based film dosimetry analysis

International Nuclear Information System (INIS)

Alexander, K M; Schreiner, L J; Robinson, A; Pinter, C; Fichtinger, G

2017-01-01

Radiochromic film dosimetry has been widely adopted in the clinic as it is a convenient option for dose measurement and verification. Film dosimetry analysis is typically performed using expensive commercial software, or custom made scripts in Matlab. However, common clinical film analysis software is not transparent regarding what corrections/optimizations are running behind the scenes. In this work, an extension to the open-source medical imaging platform 3D Slicer was developed and implemented in our centre for film dosimetry analysis. This extension streamlines importing treatment planning system dose and film imaging data, film calibration, registration, and comparison of 2D dose distributions, enabling greater accessibility to film analysis and higher reliability. (paper)

Statistical analysis on experimental calibration data for flowmeters in pressure pipes

Science.gov (United States)

Lazzarin, Alessandro; Orsi, Enrico; Sanfilippo, Umberto

2017-08-01

This paper shows a statistical analysis on experimental calibration data for flowmeters (i.e.: electromagnetic, ultrasonic, turbine flowmeters) in pressure pipes. The experimental calibration data set consists of the whole archive of the calibration tests carried out on 246 flowmeters from January 2001 to October 2015 at Settore Portate of Laboratorio di Idraulica “G. Fantoli” of Politecnico di Milano, that is accredited as LAT 104 for a flow range between 3 l/s and 80 l/s, with a certified Calibration and Measurement Capability (CMC) - formerly known as Best Measurement Capability (BMC) - equal to 0.2%. The data set is split into three subsets, respectively consisting in: 94 electromagnetic, 83 ultrasonic and 69 turbine flowmeters; each subset is analysed separately from the others, but then a final comparison is carried out. In particular, the main focus of the statistical analysis is the correction C, that is the difference between the flow rate Q measured by the calibration facility (through the accredited procedures and the certified reference specimen) minus the flow rate QM contemporarily recorded by the flowmeter under calibration, expressed as a percentage of the same QM .

New instrument calibration facility for the DOE Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Wilkie, W.H.; Polz, E.J. [Westinghouse Savannah River Company, Aiken, SC (United States)

1993-12-31

A new laboratory facility is being designed, constructed, and equipped at the Savannah River Site (SRS) as a fiscal year 1992 line item project. This facility will provide space and equipment for test, evaluation, repair, maintenance, and calibration of radiation monitoring instrumentation. The project will replace an obsolete facility and will allow implementation of program upgrades necessary to meet ANSI N323 requirements and National Voluntary Laboratory Accreditation Program (NVLAP) criteria for accreditation of federally owned secondary calibration laboratories. An outline of the project is presented including description, scope, cost, management organization, chronology, and current status. Selected design criteria and their impacts on the project are discussed. The upgraded SRS calibration program is described, and important features of the new facility and equipment that will accommodate this program are listed. The floor plan for the facility is shown, and equipment summaries and functional descriptions for each area are provided.

New instrument calibration facility for the DOE Savannah River Site

International Nuclear Information System (INIS)

Wilkie, W.H.; Polz, E.J.

1993-01-01

A new laboratory facility is being designed, constructed, and equipped at the Savannah River Site (SRS) as a fiscal year 1992 line item project. This facility will provide space and equipment for test, evaluation, repair, maintenance, and calibration of radiation monitoring instrumentation. The project will replace an obsolete facility and will allow implementation of program upgrades necessary to meet ANSI N323 requirements and National Voluntary Laboratory Accreditation Program (NVLAP) criteria for accreditation of federally owned secondary calibration laboratories. An outline of the project is presented including description, scope, cost, management organization, chronology, and current status. Selected design criteria and their impacts on the project are discussed. The upgraded SRS calibration program is described, and important features of the new facility and equipment that will accommodate this program are listed. The floor plan for the facility is shown, and equipment summaries and functional descriptions for each area are provided

Intercalibration of radiological measurements for surveillance purposes of the internal dosimetry laboratory coordinated by the IAEA

International Nuclear Information System (INIS)

Alfaro L, M.M.

2002-07-01

The ININ of Mexico participated in this intercomparison organized by the IAEA in 2000. The objective of this activity is that the dosimetry laboratories that participate can validate the programs of internal dosimetry, with the purpose of improving its capacity in the evaluation of the internal dose and have access to a mechanism to evaluate its dosimetry system under real conditions. The specific objectives of this intercomparison were: 1. To evaluate the participant's capacity to manage the measurements of individual monitoring in terms of the activity in the phantom. 2. To provide the access to the unique calibration resources that otherwise would not be available. 3. To compare the operation of several detection systems, the geometry, phantoms, calibration methods and methods for the evaluation of activity of the radionuclide used by each institution. 4. To provide the independent verification of the direct measurement methods of the dosimetry service. (Author)

Interlaboratory niobium dosimetry comparison

International Nuclear Information System (INIS)

Wille, P.

1980-01-01

For an interlaboratory comparison of neutron dosimetry using niobium the 93 sup(m)Nb activities of irradiated niobium monitors were measured. This work was performed to compare the applied techniques of dosimetry with Nb in different laboratories. The niobium monitors were irradiated in the fast breeder EBRII, USA and the BR2, Belgium. The monitors were dissolved and several samples were prepared. Their niobium contents were determined by the 94 Nb-count rates. since the original specific count rate was known. The KX radiations of the 93 sup(m)Nb of the samples and of a calibrated Nb-foil were compared. This foil was measured by PTB, Braunschweig and CBNM, Geel, which we additionally compared with the KX radiation of 88 Sr produced by a thin 88 Y source from a 88 Y-standard solution (PTB). (orig.) [de

A method to improve application technique in Alanine/ESR dosimetry

International Nuclear Information System (INIS)

Choi, Hoon; Ha, Ju Hee; Choi, Won; Lim, Young Khi

2008-01-01

Full text: For long-term radiation monitoring to assess the cable aging in harsh condition of nuclear power plant, ESR dosimetry method using alanine dosimeters was already recommended in many technical document and paper. Several ESR dosimetry systems were already produced and used widely, but the actual application of these systems for industrial dosimetry needs careful consideration of error sources in process of dose measurement. The alanine dosimeters were measured by E-scan alanine analyzer system or EMX ESR spectrometer. For the accurate measurement of the dosimeters, we have studied various source of errors. First, this paper discusses sources of inaccuracy related to data processing. To make a meaningful dose assessment, the dosimeter measurements need to be compared with measurements made using certified dosimeters of known dose. This is achieved by performing the routine calibration procedure which creates a calibration curve and corresponding fit coefficients from measurements made with a set of dosimeters with known certified dose. The calibration curves in ESR dosimetry are usually constructed by means of the least-squares technique in its simplest variant. The recommended alternative linearity several replicate measurements of Y at each used X value. Also, measurement is subject to error, so repeat measurements will not be identical. A technical description of a linear calibration is assumed that the dispersion of the measurements is the same for each standard. But in some cases, the standard deviation has to be specified separately for each value of concentration. In this case, it used the WLS (Weighted Least-Squared Regression) method instead of the OLS (Ordinary Least-Squared Regression) method. Second, the precision of the ESR spectrum was showed as a reproducibility test for the two ESR systems. The reproducibility test was performed at an absorbed dose of 1 k Gy, which is at least three orders of magnitude above the background reading of an

Accreditation and Educational Quality: Are Students in Accredited Programs More Academically Engaged?

Science.gov (United States)

Cole, James S.; Cole, Shu T.

2008-01-01

There has been a great deal of debate regarding the value of program accreditation. Two research questions guided this study: 1) are students enrolled in accredited parks, recreation, and leisure programs more academically engaged than students enrolled in non-accredited programs, and 2) do students enrolled in accredited parks, recreation, and…

Quality assurance programs at the PNL calibrations laboratory

International Nuclear Information System (INIS)

Piper, R.K.; McDonald, J.C.; Fox, R.A.; Eichner, F.N.

1993-03-01

The calibrations laboratory at Pacific Northwest Laboratory (PNL) serves as a radiological standardization facility for personnel and environmental dosimetry and radiological survey instruments. As part of this function, the calibrations laboratory must maintain radiological reference fields with calibrations traceable to the National Institute of Standards and Technology (NIST). This task is accomplished by a combination of (1) sources or reference instruments calibrated at or by NIST, (2) measurement quality assurance (MQA) interactions with NIST, and (3) rigorous internal annual and quarterly calibration verifications. This paper describes a representative sample of the facilities, sources, and actions used to maintain accurate and traceable fields

Calibration of sources for alpha spectroscopy systems

International Nuclear Information System (INIS)

Freitas, I.S.M.; Goncalez, O.L.

1992-01-01

This paper describes the calibration methodology for measuring the total alpha activity of plane and thin sources with the Alpha Spectrometer for Silicon Detector in the Nuclear Measures and Dosimetry laboratory at IEAv/CTA. (author)

Practical applications of the new ICRP recommendation to external dosimetry

International Nuclear Information System (INIS)

Kraus, W.

1992-01-01

Focussing on external dosimetry for occupational exposure the consequences of the new quantities equivalent dose (radiation weighting factor), effective dose (tissue weighting factor) and the ICRU operational quantities for individual and area dosimetry are discussed. Despite some arguments against the new quantities they should be introduced as rapidly as possible to keep international uniformity in radiation protection monitoring. It is shown that they provide a conservative estimate of the effective dose for photons and neutrons. In photon dosimetry only minor changes of the conversion factors relating operational quantities to effective dose is observed. In neutron dosimetry the conversion factors change by a factor of up to 2. It is pointed out that there is a urgent need to calculate standardized conversion factors for field quantities -operational quantities- organ and effective dose in a joint effort of ICRP and ICRU. This includes standardization of calibration methods for individual dosimetry using suitable phantoms instead of the sphere. (author)

Dosimeter calibration facilities and methods at the Radiation Measurement Laboratory of the Centre d'etudes nucleaires, Grenoble

International Nuclear Information System (INIS)

Choudens, H. de; Herbaut, Y.; Haddad, A.; Giroux, J.; Rouillon, J.; CEA Centre d'Etudes Nucleaires de Grenoble, 38

1975-01-01

At the Centre d'etudes nucleaires, Grenoble, the Radiation Measurement Laboratory, which forms part of the Environmental Protection and Research Department, serves the entire Centre for purposes of dosimetry and the calibration of dose meters. The needs of radiation protection are such that one must have facilities for checking periodically the calibration of radiation-monitoring instruments and developing special dosimetry techniques. It was thought a good idea to arrange for the dosimetry and radiation protection team to assist other groups working at the Centre - in particular, the staff of the biology and radiobiology laboratories - and also bodies outside the framework of the French Commissariat a l'energie atomique. Thus, technical collaboration has been established with, for example, Grenoble's Centre hospitalier universitaire (university clinic), which makes use of the facilities and skills available at the Radiation Measurement Laboratory for solving special dosimetry problems. With the Laboratory's facilities it is possible to calibrate dose meters for gamma, beta and neutron measurements

Automation of radiation dosimetry using PTW dosemeter and LabVIEWTM

International Nuclear Information System (INIS)

Weiss, C.; Al-Frouh, K.; Anjak, O.

2011-01-01

Automation of UNIDOS 'Dosemeter' using personal computer (PC) is discussed in this paper. In order to save time and eliminate human operation errors during the radiation dosimetry, suitable software, using LabVIEW TM graphical programming language, was written to automate and facilitate the processes of measurements, analysis and data storage. The software calculates the calibration factor of the ionization chamber in terms of air kerma or absorbed dose to water according to IAEA dosimetry protocols. It also has the ability to print a calibration certificate. The obtained results using this software are found to be more reliable and flexible than those obtained by manual methods previously employed. Using LabVIEW TM as a development tool is extremely convenient to make things easier when software modifications and improvements are needed.

Relative dosimetry by Ebt-3; Dosimetria relativa por EBT3

Energy Technology Data Exchange (ETDEWEB)

De Leon A, M. A.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, 11500 Mexico D. F. (Mexico); Hernandez O, J. O., E-mail: madla16@hotmail.com [Hospital General de Mexico, Dr. Balmis 148, Col. Doctores, 06726 Mexico D. F. (Mexico)

2015-10-15

In the present work relative dosimetry in two linear accelerator for radiation therapy was studied. Both Varian Oncology systems named Varian Clinac 2100-Cd and MLC Varian Clinac i X were used. Gaf Chromic Ebt-3 film was used. Measurements have been performed in a water equivalent phantom, using 6 MV and 18 MV photon beams on both Linacs. Both calibration and Electron irradiations were carried out with the ionization chamber placed at the isocenter, below a stack of solid water slabs, at the depth of dose maximum (D max), with a Source-to-Surface Distance (SSD) of 100 cm and a field size of 10 cm x 10 cm. Calibration and dosimetric measurements photons were carried out under IAEA-TRS 398 protocol. Results of relative dosimetry in the present work are discussed. (Author)

Training Accreditation Program

International Nuclear Information System (INIS)

1989-01-01

The Training Accreditation Program establishes the objectives and criteria against which DOE nuclear facility training is evaluated to determine its readiness for accreditation. Training programs are evaluated against the accreditation objectives and criteria by facility personnel during the initial self-evaluation process. From this self-evaluation, action plans are made by the contractor to address the scope of work necessary in order to upgrade any deficiencies noted. This scope of work must be formally documented in the Training Program Accreditation Plan. When reviewed and approved by the responsible Head of the Field Organization and cognizant Program Secretarial Office, EH-1 concurrence is obtained. This plan then becomes the document which guides accreditation efforts for the contractor

Performance comparisons of selected personnel-dosimetry systems in use at Department of Energy facilities

International Nuclear Information System (INIS)

Roberson, P.L; Holbrook, K.L.; Yoder, R.C.; Fox, R.A.; Hadley, R.T.; Hogan, B.T.; Hooker, C.D.

1983-10-01

Dosimeter performance data were collected to help develop a uniform approach to the calibration and use of personnel dosimetry systems for Department of Energy (DOE) laboratories. Eleven DOE laboratories participated in six months of testing using the American National Draft Standard, Criteria for Testing Personnel Dosimetry Performance, ANSI N13.11, and additional testing categories. The tests described in ANSI N13.11 used a pass/fail system to determine compliance with the draft standard. Recalculation to PNL irradiations showed that the 137 Cs, 90 Sr/ 90 Y, and 252 Cf categories can be recalibrated to have acceptable performance for nearly all participant systems. Deficient dosimeter design or handling techniques caused poor performance in the x-ray category for nearly half of the participants. Too little filtration for the deep-dose element caused poor performance in the beta/photon mixture category for one participant. Two participants had excessively high standard deviations in the neutron category due to dosimeter design or handling deficiencies. The participating dosimetry systems were separated into three categories on their dose evaluation procedure for low-energy photons. These were film dosimeters, fixed-calibration thermoluminescent (TL) dosimeters, and variable-calibration TL dosimeters. The performance of the variable-calibration design was best while the film dosimeters performed considerably worse than either TL dosimeter design. Beta energy dependence studies confirmed a strong correlation between sensitive element thickness, shallow element filtration and low-energy beta response. Studies of neutron calibration conditions for each participant suggested a relationship between response and calibration facility design

Calibration Laboratory of the Paul Scherrer Institute

International Nuclear Information System (INIS)

Gmuer, K.; Wernli, C.

1994-01-01

Calibration and working checks of radiation protection instruments are carried out at the Calibration Laboratory of the Paul Scherrer Institute. In view of the new radiation protection regulation, the calibration laboratory received an official federal status. The accreditation procedure in cooperation with the Federal Office of Metrology enabled a critical review of the techniques and methods applied. Specifically, personal responsibilities, time intervals for recalibration of standard instruments, maximum permissible errors of verification, traceability and accuracy of the standard instruments, form and content of the certificates were defined, and the traceability of the standards and quality assurance were reconsidered. (orig.) [de

Design, comparison, and testing of a new user-friendly extremity dosimetry system

Energy Technology Data Exchange (ETDEWEB)

Stadtmann, H.; Schmitzer, C.; Michler, E. [Austrian Research Centre, Seibersdorf (Austria); Fellinger, J.; Velbeck, K.J.; Rotunda, J.E. [BICRON RMP, Solon (United States)

2000-05-01

A new extremity TLD system has been developed and tested that provides for user convenience and automated processing while meeting various accreditation requirements. The design is a result of successful collaboration among organisational entities in different countries and included research centres, users, and the manufacturer. The primary consideration was to meet the needs of the medical market, without losing sight of the needs of research laboratories and power plants. This dosimetry system design provides various detector designs based on the need to measure photons or betas. Beyond the fundamental need for accurate dosimetry, the system meets the customers need for a versatile and comfortable ring and provides for both hot and cold sterilisation. The system represents a unique integration of components comprising the finger ring, dosimeter and dosimeter identification system, and TLD Instruments. The dosimeter identification system in the TLD Reader incorporates a CCD Camera and Machine Vision Technology to interpret the circular bar codes used to quickly and accurately identifies each individual dosimeter. Portability of this dosimetry system has been realised with the adaptation into multiple TLD Instruments. (author)

Design, comparison, and testing of a new user-friendly extremity dosimetry system

International Nuclear Information System (INIS)

Stadtmann, H.; Schmitzer, C.; Michler, E.; Fellinger, J.; Velbeck, K.J.; Rotunda, J.E.

2000-01-01

A new extremity TLD system has been developed and tested that provides for user convenience and automated processing while meeting various accreditation requirements. The design is a result of successful collaboration among organisational entities in different countries and included research centres, users, and the manufacturer. The primary consideration was to meet the needs of the medical market, without losing sight of the needs of research laboratories and power plants. This dosimetry system design provides various detector designs based on the need to measure photons or betas. Beyond the fundamental need for accurate dosimetry, the system meets the customers need for a versatile and comfortable ring and provides for both hot and cold sterilisation. The system represents a unique integration of components comprising the finger ring, dosimeter and dosimeter identification system, and TLD Instruments. The dosimeter identification system in the TLD Reader incorporates a CCD Camera and Machine Vision Technology to interpret the circular bar codes used to quickly and accurately identifies each individual dosimeter. Portability of this dosimetry system has been realised with the adaptation into multiple TLD Instruments. (author)

Performance testing of UK personal dosimetry laboratories

CERN Document Server

Marshall, T O

1985-01-01

The proposed Ionising Radiations Regulations will require all UK personal dosimetry laboratories that monitor classified personnel to be approved for personal dosimetry by the Health and Safety Executive. It is suggested that these approvals should be based on general and supplementary criteria published by the British Calibration Service (BCS) for laboratory approval for the provision of personal dosimetry services. These criteria specify certain qualitative requirements and also indicate the need for regular tests of performance to be carried out to ensure constancy of dosimetric standards. This report concerns the latter. The status of the BCS criteria is discussed and the need for additional documents to cover new techniques and some modifications to existing documents is indicated. A means is described by which the technical performance of laboratories, concerned with personal monitoring for external radiations, can be assessed, both initially and ongoing. The costs to establish the scheme and operate it...

Improving the accuracy of ionization chamber dosimetry in small megavoltage x-ray fields

Science.gov (United States)

McNiven, Andrea L.

The dosimetry of small x-ray fields is difficult, but important, in many radiation therapy delivery methods. The accuracy of ion chambers for small field applications, however, is limited due to the relatively large size of the chamber with respect to the field size, leading to partial volume effects, lateral electronic disequilibrium and calibration difficulties. The goal of this dissertation was to investigate the use of ionization chambers for the purpose of dosimetry in small megavoltage photon beams with the aim of improving clinical dose measurements in stereotactic radiotherapy and helical tomotherapy. A new method for the direct determination of the sensitive volume of small-volume ion chambers using micro computed tomography (muCT) was investigated using four nominally identical small-volume (0.56 cm3) cylindrical ion chambers. Agreement between their measured relative volume and ionization measurements (within 2%) demonstrated the feasibility of volume determination through muCT. Cavity-gas calibration coefficients were also determined, demonstrating the promise for accurate ion chamber calibration based partially on muCT. The accuracy of relative dose factor measurements in 6MV stereotactic x-ray fields (5 to 40mm diameter) was investigated using a set of prototype plane-parallel ionization chambers (diameters of 2, 4, 10 and 20mm). Chamber and field size specific correction factors ( CSFQ ), that account for perturbation of the secondary electron fluence, were calculated using Monte Carlo simulation methods (BEAM/EGSnrc simulations). These correction factors (e.g. CSFQ = 1.76 (2mm chamber, 5mm field) allow for accurate relative dose factor (RDF) measurement when applied to ionization readings, under conditions of electronic disequilibrium. With respect to the dosimetry of helical tomotherapy, a novel application of the ion chambers was developed to characterize the fan beam size and effective dose rate. Characterization was based on an adaptation of the

Direct megavoltage photon calibration service in Australia

International Nuclear Information System (INIS)

Butler, D.J.; Ramanthan, G.; Oliver, C.; Cole, A.; Harty, P.D.; Wright, T.; Webb, D.V.; Lye, J.; Followill, D.S.

2014-01-01

The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) maintains the Australian primary standard of absorbed dose. Until recently, the standard was used to calibrate ionisation chambers only in 60 Co gamma rays. These chambers are then used by radiotherapy clinics to determine linac output, using a correction factor (k Q ) to take into account the different spectra of 60 Co and the linac. Over the period 2010–2013, ARPANSA adapted the primary standard to work in megavoltage linac beams, and has developed a calibration service at three photon beams (6, 10 and 18 MV) from an Elekta Synergy linac. We describe the details of the new calibration service, the method validation and the use of the new calibration factors with the International Atomic Energy Agency’s TRS-398 dosimetry Code of Practice. The expected changes in absorbed dose measurements in the clinic when shifting from 60 Co to the direct calibration are determined. For a Farmer chamber (model 2571), the measured chamber calibration coefficient is expected to be reduced by 0.4, 1.0 and 1.1 % respectively for these three beams when compared to the factor derived from 60 Co. These results are in overall agreement with international absorbed dose standards and calculations by Muir and Rogers in 2010 of k Q factors using Monte Carlo techniques. The reasons for and against moving to the new service are discussed in the light of the requirements of clinical dosimetry.

Calibration of working standard ionization chambers and dose standardization

International Nuclear Information System (INIS)

Abd Elmahoud, A. A. B.

2011-01-01

Measurements were performed for the calibration of two working standard ionization chambers in the secondary standard dosimetry laboratory of Sudan. 600 cc cylindrical former type and 1800 cc cylindrical radical radiation protection level ionization chambers were calibrated against 1000 cc spherical reference standard ionization chamber. The chamber were calibrated at X-ray narrow spectrum series with beam energies ranged from (33-116 KeV) in addition to 1''3''7''Cs beam with 662 KeV energy. The chambers 0.6 cc and 0.3 cc therapy level ionization were used for dose standardization and beam output calibrations of cobalt-60 radiotherapy machine located at the National Cancer Institute, University of Gazira. Concerning beam output measurements for 6''0''Co radiotherapy machine, dosimetric measurements were performed in accordance with the relevant per IAEA dosimetry protocols TRS-277 and TRS-398. The kinetic energy released per unit mass in air (air kerma) were obtained by multiplying the corrected electrometer reading (nC/min) by the calibration factors (Gy/n C) of the chambers from given in the calibration certificate. The uncertainty of measurements of air kerma were calculated for the all ionization chambers (combined uncertainty) the calibration factors of these ionization chambers then were calculated by comparing the reading of air kerma of secondary standard ionization chambers to than from radical and farmer chambers. The result of calibration working standard ionization chambers showed different calibration factors ranged from 0.99 to 1.52 for different radiation energies and these differences were due to chambers response and specification. The absorbed dose to to water calculated for therapy ionization chamber using two code of practice TRS-277 and TRS-398 as beam output for 6''0''Co radiotherapy machine and it can be used as a reference for future beam output calibration in radiotherapy dosimetry. The measurement of absorbed dose to water showed that the

Use of Balance Calibration Certificate to Calculate the Errors of Indication and Measurement Uncertainty in Mass Determinations Performed in Medical Laboratories

Directory of Open Access Journals (Sweden)

Adriana VÂLCU

2011-09-01

Full Text Available Based on the reference document, the article proposes the way to calculate the errors of indication and associated measurement uncertainties, by resorting to the general information provided by the calibration certificate of a balance (non-automatic weighing instruments, shortly NAWI used in medical field. The paper may be also considered a useful guideline for: operators working in laboratories accredited in medical (or other various fields where the weighing operations are part of their testing activities; test houses, laboratories, or manufacturers using calibrated non-automatic weighing instruments for measurements relevant for the quality of production subject to QM requirements (e.g. ISO 9000 series, ISO 10012, ISO/IEC 17025; bodies accrediting laboratories; accredited laboratories for the calibration of NAWI. Article refers only to electronic weighing instruments having maximum capacity up to 30 kg. Starting from the results provided by a calibration certificate it is presented an example of calculation.

Components of laboratory accreditation.

Science.gov (United States)

Royal, P D

1995-12-01

Accreditation or certification is a recognition given to an operation or product that has been evaluated against a standard; be it regulatory or voluntary. The purpose of accreditation is to provide the consumer with a level of confidence in the quality of operation (process) and the product of an organization. Environmental Protection Agency/OCM has proposed the development of an accreditation program under National Environmental Laboratory Accreditation Program for Good Laboratory Practice (GLP) laboratories as a supplement to the current program. This proposal was the result of the Inspector General Office reports that identified weaknesses in the current operation. Several accreditation programs can be evaluated and common components identified when proposing a structure for accrediting a GLP system. An understanding of these components is useful in building that structure. Internationally accepted accreditation programs provide a template for building a U.S. GLP accreditation program. This presentation will discuss the traditional structure of accreditation as presented in the Organization of Economic Cooperative Development/GLP program, ISO-9000 Accreditation and ISO/IEC Guide 25 Standard, and the Canadian Association for Environmental Analytical Laboratories, which has a biological component. Most accreditation programs are managed by a recognized third party, either privately or with government oversight. Common components often include a formal review of required credentials to evaluate organizational structure, a site visit to evaluate the facility, and a performance evaluation to assess technical competence. Laboratory performance is measured against written standards and scored. A formal report is then sent to the laboratory indicating accreditation status. Usually, there is a scheduled reevaluation built into the program. Fee structures vary considerably and will need to be examined closely when building a GLP program.

Dosimetry; La dosimetrie

Energy Technology Data Exchange (ETDEWEB)

Le Couteulx, I.; Apretna, D.; Beaugerie, M.F. [Electricite de France (EDF), 75 - Paris (France)] [and others

2003-07-01

Eight articles treat the dosimetry. Two articles evaluate the radiation doses in specific cases, dosimetry of patients in radiodiagnosis, three articles are devoted to detectors (neutrons and x and gamma radiations) and a computer code to build up the dosimetry of an accident due to an external exposure. (N.C.)

Impact of SPECT corrections on 3D-dosimetry for liver transarterial radioembolization using the patient relative calibration methodology

Energy Technology Data Exchange (ETDEWEB)

Pacilio, Massimiliano, E-mail: mpacilio@scamilloforlanini.rm.it; Basile, Chiara [Department of Medical Physics, Azienda Ospedaliera San Camillo Forlanini, Rome 00152 (Italy); Ferrari, Mahila; Botta, Francesca; Cremonesi, Marta [Department of Medical Physics, Istituto Europeo di Oncologia, Milan 20141 (Italy); Chiesa, Carlo [Department of Nuclear Medicine, Istituto Nazionale Tumori IRCCS Foundation, Milan 20133 (Italy); Lorenzon, Leda; Becci, Domenico [Postgraduate School of Medical Physics, “Sapienza” University of Rome, Rome 00185 (Italy); Mira, Marta [Post graduate Health Physics School, University of Milan, Milan 20122 (Italy); Torres, Leonel Alberto; Vergara Gil, Alex [Department of Nuclear Medicine, Clinical Research Division of the Center of Isotopes (DIC-CENTIS), Havana 11100 (Cuba); Coca Perez, Marco [Department of PET-CT and Nuclear Medicine, Imaging Center Medscan-Concepciòn, Concepciòn 4070061 (Chile); Ljungberg, Michael [Department of Medical Radiation Physics, University of Lund, Lund 22100 (Sweden); Pani, Roberto [Department of Medico-surgical Sciences and Biotecnologies, “Sapienza” University of Rome, Rome 00185 (Italy)

2016-07-15

Purpose: Many centers aim to plan liver transarterial radioembolization (TARE) with dosimetry, even without CT-based attenuation correction (AC), or with unoptimized scatter correction (SC) methods. This work investigates the impact of presence vs absence of such corrections, and limited spatial resolution, on 3D dosimetry for TARE. Methods: Three voxelized phantoms were derived from CT images of real patients with different body sizes. Simulations of {sup 99m}Tc-SPECT projections were performed with the SIMIND code, assuming three activity distributions in the liver: uniform, inside a “liver’s segment,” or distributing multiple uptaking nodules (“nonuniform liver”), with a tumoral liver/healthy parenchyma ratio of 5:1. Projection data were reconstructed by a commercial workstation, with OSEM protocol not specifically optimized for dosimetry (spatial resolution of 12.6 mm), with/without SC (optimized, or with parameters predefined by the manufacturer; dual energy window), and with/without AC. Activity in voxels was calculated by a relative calibration, assuming identical microspheres and {sup 99m}Tc-SPECT counts spatial distribution. 3D dose distributions were calculated by convolution with {sup 90}Y voxel S-values, assuming permanent trapping of microspheres. Cumulative dose-volume histograms in lesions and healthy parenchyma from different reconstructions were compared with those obtained from the reference biodistribution (the “gold standard,” GS), assessing differences for D95%, D70%, and D50% (i.e., minimum value of the absorbed dose to a percentage of the irradiated volume). γ tool analysis with tolerance of 3%/13 mm was used to evaluate the agreement between GS and simulated cases. The influence of deep-breathing was studied, blurring the reference biodistributions with a 3D anisotropic gaussian kernel, and performing the simulations once again. Results: Differences of the dosimetric indicators were noticeable in some cases, always negative

Metrology and quality of radiation therapy dosimetry of electron, photon and epithermal neutron beams

Energy Technology Data Exchange (ETDEWEB)

Kosunen, A

1999-08-01

In radiation therapy using electron and photon beams the dosimetry chain consists of several sequential phases starting by the realisation of the dose quantity in the Primary Standard Dosimetry Laboratory and ending to the calculation of the dose to a patient. A similar procedure can be described for the dosimetry of epithermal neutron beams in boron neutron capture therapy (BNCT). To achieve the required accuracy of the dose delivered to a patient the quality of all steps in the dosimetry procedure has to be considered. This work is focused on two items in the dosimetry chains: the determination of the dose in the reference conditions and the evaluation of the accuracy of dose calculation methods. The issues investigated and discussed in detail are: a)the calibration methods of plane parallel ionisation chambers used in electron beam dosimetry, (b) the specification of the critical dosimetric parameter i.e. the ratio of stopping powers for water to air, (S I ?){sup water} {sub air}, in photon beams, (c) the feasibility of the twin ionization chamber technique for dosimetry in epithermal neutron beams applied to BNCT and (d) the determination accuracy of the calculated dose distributions in phantoms in electron, photon, and epithermal neutron beams. The results demonstrate that up to a 3% improvement in the consistency of dose determinations in electron beams is achieved by the calibration of plane parallel ionisation chambers in high energy electron beams instead of calibrations in {sup 60}Co gamma beams. In photon beam dosimetry (S I ?){sup water} {sub air} can be determined with an accuracy of 0.2% using the percentage dose at the 10 cm depth, %dd(10), as a beam specifier. The use of %odd(10) requires the elimination of the electron contamination in the photon beam. By a twin ionisation chamber technique the gamma dose can be determined with uncertainty of 6% (1 standard deviation) and the total neutron dose with an uncertainty of 15 to 20% (1 standard deviation

Metrology and quality of radiation therapy dosimetry of electron, photon and epithermal neutron beams

International Nuclear Information System (INIS)

Kosunen, A.

1999-08-01

In radiation therapy using electron and photon beams the dosimetry chain consists of several sequential phases starting by the realisation of the dose quantity in the Primary Standard Dosimetry Laboratory and ending to the calculation of the dose to a patient. A similar procedure can be described for the dosimetry of epithermal neutron beams in boron neutron capture therapy (BNCT). To achieve the required accuracy of the dose delivered to a patient the quality of all steps in the dosimetry procedure has to be considered. This work is focused on two items in the dosimetry chains: the determination of the dose in the reference conditions and the evaluation of the accuracy of dose calculation methods. The issues investigated and discussed in detail are: a)the calibration methods of plane parallel ionisation chambers used in electron beam dosimetry, (b) the specification of the critical dosimetric parameter i.e. the ratio of stopping powers for water to air, (S I ?) water air , in photon beams, (c) the feasibility of the twin ionization chamber technique for dosimetry in epithermal neutron beams applied to BNCT and (d) the determination accuracy of the calculated dose distributions in phantoms in electron, photon, and epithermal neutron beams. The results demonstrate that up to a 3% improvement in the consistency of dose determinations in electron beams is achieved by the calibration of plane parallel ionisation chambers in high energy electron beams instead of calibrations in 60 Co gamma beams. In photon beam dosimetry (S I ?) water air can be determined with an accuracy of 0.2% using the percentage dose at the 10 cm depth, %dd(10), as a beam specifier. The use of %odd(10) requires the elimination of the electron contamination in the photon beam. By a twin ionisation chamber technique the gamma dose can be determined with uncertainty of 6% (1 standard deviation) and the total neutron dose with an uncertainty of 15 to 20% (1 standard deviation). To improve the accuracy

Secondary standard dosimetry system with automatic dose/rate calculation

International Nuclear Information System (INIS)

Duftschmid, K.E.; Bernhart, J.; Stehno, G.; Klosch, W.

1980-01-01

A versatile and automated secondary standard instrument has been designed for quick and accurate dose/rate measurement in a wide range of radiation intensity and quality (between 1 μR and 100 kR; 0.2 nC/kg - 20C/kg) for protection and therapy level dosimetry. The system is based on a series of secondary standard ionization chambers connected to a precision digital current integrator with microprocessor circuitry for data evaluation and control. Input of measurement parameters and calibration factors stored in an exchangeable memory chip provide computation of dose/rate values in the desired units. The ionization chambers provide excellent long-term stability and energy response and can be used with internal check sources to test validity of calibration. The system is a useful tool particularly for daily measurements in a secondary standard dosimetry laboratory or radiation therapy center. (H.K.)

Accredited dose measurements for validation of radiation sterilized products

DEFF Research Database (Denmark)

Miller, A.

1993-01-01

for control of radiation sterilization. The accredited services include: 1. 1. Irradiation of dosimeters and test samples with cobalt-60 gamma rays. 2. 2. Irradiation of dosimeters and test samples with 10 MeV electrons. 3. 3. Issue of and measurement with calibrated dosimeters. 4. 4. Measurement...... of the dosimetric parameters of an irradiation facility. 5. 5. Measurement of absorbed dose distribution in irradiated products. The paper describes these services and the procedures necessary for their execution....

Polymer gel dosimeters with enhanced sensitivity for use in x-ray CT polymer gel dosimetry

International Nuclear Information System (INIS)

Jirasek, A; Hilts, M; McAuley, K B

2010-01-01

A primary limitation of current x-ray CT polymer gel dosimetry is the low contrast, and hence poor dose resolution, of dose images produced by the system. The low contrast is largely due to the low-dose sensitivity of current formulations of polymer gel for x-ray CT imaging. This study reports on the investigation of new dosimeter formulations with improved dose sensitivity for x-ray CT polymer gel dosimetry. We incorporate an isopropanol co-solvent into an N-isopropylacrylamide-based gel formulation in order to increase the total monomer/crosslinker concentration (%T) within the formulation. It is shown that gels of high %T exhibit enhanced dose sensitivity and dose resolutions over traditional formulations. The gels are shown to be temporally stable and reproducible. A single formulation (16%T) is used to demonstrate the capabilities of the x-ray CT polymer gel dosimetry system in measuring known dose distributions. A 1 L gel volume is exposed to three separate irradiations: a single-field percent depth dose, a two-field 'cross' and a three-field 'test case'. The first two irradiations are used to generate a dose calibration curve by which images are calibrated. The calibrated images are compared with treatment planning predictions and it is shown that the x-ray CT polymer gel dosimetry system is capable of capturing spatial and dose information accurately. The proposed new gel formulation is shown to be sensitive, stable and to improve the dose resolution over current formulations so as to provide a feasible gel for clinical applications of x-ray CT polymer gel dosimetry.

Characterization of a 137Cs standard source for calibration purposes at CRCN-NE

International Nuclear Information System (INIS)

Oliveira, Mercia L.; Santos, Marcus A.P. dos; Benvides, Clayton A.

2008-01-01

Radiation protection monitoring instruments should be calibrated by accredited calibration laboratories. To offer calibration services, a laboratory must accomplish all requirements established by the national regulatory agency. The Calibration Service of the Centro Regional de Ciencias Nucleares (CRCN-NE), Comissao Nacional de Energia Nuclear, Recife, Brazil, is trying to achieve this accreditation. In the present work, a 137 Cs standard source was characterized following the national and international recommendations and the results are presented. This source is a commercially available single source irradiator model 28-8A, manufactured by J.L. Shepherd and Associates, with initial activity of 444 GBq (05/13/03). To provide different air kerma rates, as required for the calibration of portable radiation monitors, this irradiator have a set of four lead attenuators with different thickness, providing attenuation factors equal to 2, 4, 10 and 100 times (nominally). The performed tests included: size and uniformity of the radiation standard field at calibration reference position, variation of the air kerma rate for different lead attenuators, determination of attenuation factors for each lead attenuator configuration, and determination of the radiation scattering at the calibration reference position. The results showed the usefulness of the 137 Cs standard source for the calibration of radiation protection monitoring detectors. (author)

Codes of practice and protocols for the dosimetry in reference conditions of proton and ion beams

International Nuclear Information System (INIS)

Vatnitsky, S.; Andreo, P.

2002-01-01

The advantages of radiotherapy protons and heavier charged-particle beams, the technological feasibility, and the clinical results obtained so far have led to the establishment of about 20 treatment facilities worldwide and plans to open another 20 proton and light-ion therapy centres in the next five years. In order to meet the expanding capabilities of treatment techniques, considerable effort has been devoted during the last fifteen years to the development of the dosimetry and calibration of such beams. This paper reviews these developments and summarizes the present status of Codes of Practice and protocols for the dosimetry in reference conditions of proton and ion beams. The first dosimetry protocol for heavy-particle radiotherapy beams, AAPM TG 20, was based on the use of Faraday cups and calorimeters, whereas ionization chamber dosimetry received little attention. Following the trends in 'nuclear particle' radiotherapy, TG 20 included recommendations for specifying 'dose to tissue'. The lack of availability of a harmonized set of data for the different particles made this protocol to include data for stopping-powers and for the mean energy required to produce and ion pair in air, W air , from multiple authors, without enough attention being paid to their consistency. The increased focus into proton beams was materialized in the publication of the ECHED Code of Practice, dedicated exclusively to protons, where ionization dosimetry received more attention than in TG 20. It was not until the publication of the Supplement to the ECHED recommendations that ionization chambers having a 60 CO calibration factor were recommended as a reference detector for proton dosimetry, and data supplied for chambers with different wall materials. The emphasis on ionization chamber-based proton dosimetry was complemented with a recommendation for using water as dosimetry phantom material and the necessary data on tissue and water to air stopping-power ratios and W air . One of

A Threat to Accreditation: Defamation Judgment against an Accreditation Team Member.

Science.gov (United States)

Flygare, Thomas J.

1980-01-01

Delaware Law School founder Alfred Avins successfully sued accreditation team member James White for defamation as a result of comments made in 1974 and 1975. An appeals brief claims Avins was a "public figure," that he consented to accreditation, and that the accreditation process deserves court protection against such suits. (PGD)

Accreditation of nuclear engineering programs

International Nuclear Information System (INIS)

Williamson, T.G.

1989-01-01

The American Nuclear Society (ANS) Professional Development and Accreditation Committee (PDAC) has the responsibility for accreditation of engineering and technology programs for nuclear and similarly named programs. This committee provides society liaison with the Accreditation Board for Engineering and Technology (ABET), is responsible for the appointment and training of accreditation visitors, nomination of members for the ABET Board and Accreditation Commissions, and review of the criteria for accreditation of nuclear-related programs. The committee is composed of 21 members representing academia and industry. The ABET consists of 19 participating bodies, primarily professional societies, and 4 affiliate bodies. Representation on ABET is determined by the size of the professional society and the number of programs accredited. The ANS, as a participating body, has one member on the ABET board, two members on the Engineering Accreditation Commission, and one on the Technology Accreditation Commission. The ABET board sets ABET policy and the commissions are responsible for accreditation visits

Internal dosimetry for occupationally exposed personnel in nuclear medicine

International Nuclear Information System (INIS)

Garcia, M.T.; Alfaro, L.M.M.; Angeles, C.A.

2013-01-01

Internal dosimetry plays an important role in nuclear medicine dosimetry control of personnel occupationally exposed, and that in recent years there has been a large increase in the use of radionuclides both in medical diagnosis as radiotherapy. But currently, in Mexico and in many parts of the world, this internal dosimetry control is not performed. The Instituto Nacional de lnvestigaciones Nucleares de Mexico (ININ) together with the Centro Oncologico de Toluca (ISEMMYM) have developed a simple and feasible methodology for monitoring of personnel working in these facilities. It was aimed to carry out the dosimetry of the personnel, due to the incorporation of I-131, using the spectrometric devices that the hospital has, a gamma camera. The first step in this methodology was to make a thyroid phantom to meet the specifications of the ninth ANSI. This phantom is compared under controlled conditions with RMC- II phantom used for system calibration of the ININ internal dosimetry (ACCUSCAN - Ll), and with another phantom developed in Brazil with ANSI specifications, in order to determine the variations in measurements due to the density of the material of each of the phantoms and adjust to the system ACCUSCAN, already certificate. Furthermore, necessary counts were performed with the gamma camera of the phantom developed at ININ, with a standard source of 133 Ba which simulates the energy of 131 I. With these data, were determined the counting efficiencies for a distance of 15 to 20 cm between the surface of the phantom and the the plate of the detectors. Another important aspect was to determine the lower limit of detection (LLD). In this paper we present the results obtained from the detectors calibration of the gamma camera of the hospital.

The UK radiotherapy dosimetry audit network

International Nuclear Information System (INIS)

Thwaites, D.I.

2002-01-01

Full text: Radiotherapy dosimetry intercomparison in the UK has been carried out in limited studies since the 1960s. However the first national dosimetry intercomparison involving all radiotherapy centres was conducted in the late 1980s. This was based on visits to each centre, using ionisation chamber dosimetry. It audited megavoltage photon beam calibration and other single field parameters. It also measured doses in a three-field 'treatment' in a trapezoidal phantom constructed from epoxy-resin water-equivalent material and compared these to locally planned doses. This included off-axis points, oblique incidence, inhomogeneities, etc. The study found mean measured beam calibration doses close to stated values (ratio 1.003), with a standard deviation (sd) of the distribution of 1.5% and 97% of doses within the pro-set 3% tolerance. For the planned multi-field irradiations, mean dose ratios (measured/stated) were 1.01 (sd 3%, 90% of results within 5%). A number of discrepancies were identified, leading to improved practice. A follow up study (mid-1990s) for electron beam audit also repeated the megavoltage photon calibration audit. For photons, an improvement was noted (mean ratio 1.003, sd 1.0%, 100% within 3%), whilst for electron beams, the mean ratio of measured/stated dose was 0.994 (sd 1.8%, 94% within 3%, 99% within 5%). In parallel with - and growing out of - this, a national audit network began to develop in 1991/2. It utilised similar methodology to the intercomparison and a network approach to allow parallel developments of the scope of the system. The network has eight regional groups, each with up to 10 radiotherapy centres, serving average populations of 7-8 million. Each group organises audits of its own centres and has developed at its own pace. Most have piloted methodology, phantoms, etc. for new audits which can then be used by other groups. All 65 UK centres are included. The network is co-ordinated by an IPEM Steering Committee (current chair

Studies on dosimetric tests applying source irradiation force of Cs-137 for using in chambers for calibration and TLD type dosimeters

International Nuclear Information System (INIS)

Ribeiro, Laila Lorena X.; Barbosa, Rugles Cesar; Correa, Rosangela S.

2011-01-01

The West Central region of Brazil does not have a basic infrastructure for research, development, training programs, and personnel dosimetry education. All of them applied to environmental, industrial and medical uses. Service deployment for irradiance of TLD, via 137 Cs irradiator J. L. SHEPHERD model 28-8A (444 activity GBq) in CRCN-CO, it is necessary to introduce procedures for calibration of the radiator and other procedures related to dosimetry and calibration. Such procedures should be repeated periodically, as necessary to introduce techniques that make the service of the CRCN-CO a template, and that meet all standards requirements for radioprotection and operation of dosimetry and calibration. The objective of this work was to evaluate the radiation field of Cs-137, and the automatic system which systematizes the calibration procedures attached to a system control target for the radiator/calibration of monitors, and portable dosimeters. (author)

CERN radiation protection (RP) calibration facilities

Energy Technology Data Exchange (ETDEWEB)

Pozzi, Fabio

2016-04-14

Radiation protection calibration facilities are essential to ensure the correct operation of radiation protection instrumentation. Calibrations are performed in specific radiation fields according to the type of instrument to be calibrated: neutrons, photons, X-rays, beta and alpha particles. Some of the instruments are also tested in mixed radiation fields as often encountered close to high-energy particle accelerators. Moreover, calibration facilities are of great importance to evaluate the performance of prototype detectors; testing and measuring the response of a prototype detector to well-known and -characterized radiation fields contributes to improving and optimizing its design and capabilities. The CERN Radiation Protection group is in charge of performing the regular calibrations of all CERN radiation protection devices; these include operational and passive dosimeters, neutron and photon survey-meters, and fixed radiation detectors to monitor the ambient dose equivalent, H*(10), inside CERN accelerators and at the CERN borders. A new state-of-the-art radiation protection calibration facility was designed, constructed and commissioned following the related ISO recommendations to replace the previous ageing (more than 30 years old) laboratory. In fact, the new laboratory aims also at the official accreditation according to the ISO standards in order to be able to release certified calibrations. Four radiation fields are provided: neutrons, photons and beta sources and an X-ray generator. Its construction did not only involve a pure civil engineering work; many radiation protection studies were performed to provide a facility that could answer the CERN calibration needs and fulfill all related safety requirements. Monte Carlo simulations have been confirmed to be a valuable tool for the optimization of the building design, the radiation protection aspects, e.g. shielding, and, as consequence, the overall cost. After the source and irradiator installation

Advances in biomedical dosimetry

International Nuclear Information System (INIS)

1981-01-01

Full text: Radiation dosimetry, the accurate determination of the absorbed dose within an irradiated body or a piece of material, is a prerequisite for all applications of ionizing radiation. This has been known since the very first radiation applications in medicine and biology, and increasing efforts are being made by radiation researchers to develop more reliable, effective and safe instruments, and to further improve dosimetric accuracy for all types of radiation used. Development of new techniques and instrumentation was particularly fast in the field of both medical diagnostic and therapeutic radiology. Thus, in Paris in October the IAEA held the latest symposium in its continuing series on dosimetry in medicine and biology. The last one was held in Vienna in 1975. High-quality dosimetry is obviously of great importance for human health, whether the objectives lie in the prevention and control of risks associated with the nuclear industry, in medical uses of radioactive substances or X-ray beams for diagnostic purposes, or in the application of photon, electron or neutron beams in radiotherapy. The symposium dealt with the following subjects: General aspects of dosimetry; Special physical and biomedical aspects; Determination of absorbed dose; Standardization and calibration of dosimetric systems; and Development of dosimetric systems. The forty or so papers presented and the discussions that followed them brought out a certain number of dominant themes, among which three deserve particular mention. - The recent generalization of the International System of Units having prompted a fundamental reassessment of the dosimetric quantities to be considered in calibrating measuring instruments, various proposals were advanced by the representatives of national metrology laboratories to replace the quantity 'exposure' (SI unit = coulomb/kg) by 'Kerma' or 'absorbed dose' (unit joule/kg, the special name of which is 'gray'), this latter being closer to the practical

Dosimetry systems for radiation processing in Japan

International Nuclear Information System (INIS)

Tamura, Naoyuki

1995-01-01

The present situation of dosimetry systems for radiation processing industry in Japan is reviewed. For gamma-rays irradiation the parallel-plate ionization chamber in TRCRE, JAERI has been placed as a reference standard dosimeter for processing-level dose. Various solid and liquid chemical dosimeters are used as routine dosimeters for gamma processing industries. Alanine dosimeters is used for the irradiation purpose which needs precise dosimetry. For electron-beam irradiation the electron current density meter and the total absorption calorimeter of TRCRE are used for the calibration of routine dosimeters. Plastic film dosimeters, such as cellulose triacetate and radiochromic dye are used as routine dosimeters for electron processing industries. When the official traceability systems for processing-level dosimetry now under investigation is completed, the ionization chamber of TRCRE is expected to have a role of the primary standard dosimeter and the specified alanine dosimeter will be nominated for the secondary or reference standard dosimeter. (author)

Performance testing of UK personal dosimetry laboratories

International Nuclear Information System (INIS)

Marshall, T.O.

1985-01-01

The proposed Ionising Radiations Regulations will require all UK personal dosimetry laboratories that monitor classified personnel to be approved for personal dosimetry by the Health and Safety Executive. It is suggested that these approvals should be based on general and supplementary criteria published by the British Calibration Service (BCS) for laboratory approval for the provision of personal dosimetry services. These criteria specify certain qualitative requirements and also indicate the need for regular tests of performance to be carried out to ensure constancy of dosimetric standards. This report concerns the latter. The status of the BCS criteria is discussed and the need for additional documents to cover new techniques and some modifications to existing documents is indicated. A means is described by which the technical performance of laboratories, concerned with personal monitoring for external radiations, can be assessed, both initially and ongoing. The costs to establish the scheme and operate it are also estimated. (author)

Activities on calibration of radiation protection instruments in Indonesia

International Nuclear Information System (INIS)

Trijoko, S.

1995-01-01

As the use of the ionizing radiation emitted by radionuclides or produced by modern machines in Indonesia has increased significantly in the past two decades, the demand for radiation protection measures has also grown up very rapidly. In the mind of Indonesian people, ionizing radiation is always associated with atomic bombs. Indonesian government has set up National Atomic Energy Agency (BATAN) through the Act No. 31/1964. The BATAN has responsibility in the research and development, implementation and inspection of the safe use of ionizing radiation for peaceful purposes, and always put a great concern on radiation protection matter. The Center for Standardization and Radiation Safety Research (CSRSR) has been founded to implement research and services in the fields of radiation safety, standardization, dosimetry, radiation health, as well as the application of nuclear techniques to medicine. In order to provide the national reference in terms of radiation dosimetry and calibration, the Secondary Standard Dosimetry Laboratory was completely set up in Jakarta by 1984. As available facilities, radiation instruments and radiation sources are described. Calibration and personal monitoring services are reported. (K.I.)

Individual monitoring dosimetry in Europe

International Nuclear Information System (INIS)

Menzel, H.G.

1991-01-01

This report discusses the various types of individual monitoring systems presently in use within the European community and neutron dosimetry research being coordinated by the EURADOS working group. Research is currently being conducted on nuclear track dosimeters, primarily with CR-39 (TM), and TLD-albedo dosimeters. Studies are being conducted on the energy and angular response of each type of dosimeter. Because the response of dosimeters depends on the energy of the neutrons, it is necessary to have spectral information to accurately assess the dose. Neutron energy spectrum measurements are being performed in typical work place environments. Work is also progressing on development of calibration sources which will be representative of the neutron energy spectrum found in typical neutron exposure situations. This work utilizes 14 MeV neutrons incident on a uranium block with various other filters. Research is also continuing on neutron dosimetry using tissue equivalent proportional counters and microdosimetric techniques. The results of intercomparisons between several different instruments are discussed. In addition to personnel dosimetry, these systems are being used to record the dose to passengers and flight crews aboard commercial aircraft

Surviving Accreditation: A QIAS Ideas Bank. Accreditation and Beyond Series, Volume I.

Science.gov (United States)

Ferry, Jan

This publication provides information on the accreditation process for early childhood education and care providers participating in the Quality Improvement and Accreditation System (QIAS), developed by the National Childcare Accreditation Council of Australia. The publication is divided into sections corresponding to steps in the…

Proficiency Testing Activities of Frequency Calibration Laboratories in Taiwan, 2009

Science.gov (United States)

2009-11-01

cht.com.tw Abstract In order to meet the requirements of ISO 17025 and the demand of TAF (Taiwan Accreditation Foundation) for calibration inter... IEC 17025 General requirements for the competence of testing and calibration laboratories. The proficiency testing results are then important...on-site evaluation, an assessment team is organized to examine the technical competence of the labs and their compliance with the requirements of ISO

Dosimetry for radiation processing

International Nuclear Information System (INIS)

Kumar, A.; Reddy, A.R.

1994-01-01

The last few years have seen a significant increase in the use of ionising radiation in industrial processes and also international trade in irradiated products. With this, the demand for internationally accepted dosimetric techniques, accredited to international standards has also increased which is further stimulated by the emergence of ISO-9000 series of standards in industries. The present paper describes some of the important dosimetric techniques used in radiation processing, the role of IAEA in evolving internationally accepted standards and work carried out at the Defence Laboratories, Jodhpur in the development of a cheap, broad dose range and simple dosimeter for routine dosimetry. For this polyhydroxy alcohols viz., mannitol, sorbitol and inositol were studied using the spectrophotometric read out method. Out of the alcohols studied mannitol was found to be most promising covering a dose range of 0.01 kGy - 100 kGy. (author). 26 refs., 3 figs., 1 tab

Polymer gel dosimeters with enhanced sensitivity for use in x-ray CT polymer gel dosimetry

Energy Technology Data Exchange (ETDEWEB)

Jirasek, A [Department of Physics and Astronomy, University of Victoria, Victoria BC V8W 3P6 (Canada); Hilts, M [Medical Physics, BC Cancer Agency-Vancouver Island Centre, Victoria BC V6R 2B6 (Canada); McAuley, K B, E-mail: jirasek@uvic.c [Department of Chemical Engineering, Queens University, Kingston, ON K7 L 3N6 (Canada)

2010-09-21

A primary limitation of current x-ray CT polymer gel dosimetry is the low contrast, and hence poor dose resolution, of dose images produced by the system. The low contrast is largely due to the low-dose sensitivity of current formulations of polymer gel for x-ray CT imaging. This study reports on the investigation of new dosimeter formulations with improved dose sensitivity for x-ray CT polymer gel dosimetry. We incorporate an isopropanol co-solvent into an N-isopropylacrylamide-based gel formulation in order to increase the total monomer/crosslinker concentration (%T) within the formulation. It is shown that gels of high %T exhibit enhanced dose sensitivity and dose resolutions over traditional formulations. The gels are shown to be temporally stable and reproducible. A single formulation (16%T) is used to demonstrate the capabilities of the x-ray CT polymer gel dosimetry system in measuring known dose distributions. A 1 L gel volume is exposed to three separate irradiations: a single-field percent depth dose, a two-field 'cross' and a three-field 'test case'. The first two irradiations are used to generate a dose calibration curve by which images are calibrated. The calibrated images are compared with treatment planning predictions and it is shown that the x-ray CT polymer gel dosimetry system is capable of capturing spatial and dose information accurately. The proposed new gel formulation is shown to be sensitive, stable and to improve the dose resolution over current formulations so as to provide a feasible gel for clinical applications of x-ray CT polymer gel dosimetry.

Dosimetry with the scanned proton beam on the PSI gantry

International Nuclear Information System (INIS)

Coray, A.; Pedroni, E.; Boehringer, T.; Lin, S.; Lomax, T.; Goitein, G.

2002-01-01

Full text: The irradiation facility at PSI is designed for the treatment of deep seated tumours with a proton beam energy of up to 270 MeV. The spot scanning technique, which uses a proton pencil beam applied to the patient, is performed on a compact isocentric gantry. An optimal three-dimensional conformation of the dose distribution to the target volume can be realized. A fast steering system and a redundant interlock system are in operation. The dose delivery is controlled by a parallel plate transmission chamber, which is calibrated in terms of number of protons per monitor unit. The therapy planning is based on an empirical model, which takes into account attenuation of primary protons and losses outside the primary beam through secondary products. The therapy plan predicts an absolute dose. The calibration of the primary monitor is done using a reference thimble ionization chamber inside a homogeneous geometrical dose volume. The reference system is calibrated in a cobalt field at the national office of metrology in terms of absorbed dose to water. The dosimetry protocol used up to last year was based on the ICRU Report Nr. 59, we have switched to the IAEA Code of Practice starting this beam period. Data on the monitor calibration for various energies and using two different reference systems will be shown. The calibration of the beam monitor using a Faraday Cup in the static pencil beam results in a good agreement with the ionization chamber measurements, with a deviation of less than 1%. Following the daily setup of the machine, an extensive quality control and safety check of the whole system is performed. The daily dosimetry quality assurance program includes: measurement of dose rate and monitor ratios; check of the beam position monitors; measurement of a depth dose curve; dose measurement in a regular dose field. The doses measured daily in a regular scanned field show a standard deviation of about 1 %. Further daily checks results, which illustrate

Calibration of a whole body counter and 'In Vivo' measurements for internal dosimetry evaluation in Chile, two years experience

International Nuclear Information System (INIS)

Pinones O, Osvaldo; Sanhueza M, Sylvia

2008-01-01

In Chile the internal Dosimetry evaluation have been doing for more than 20 years ago by 'in vitro' measurements, however the 'in vivo' measurements just have available for 2 years due to the installation, calibration and completion of a Whole Body Counter. The Whole Body Counter of the CCHEN, corresponds to the shielded room type (4.2 x 3.3 x 2.0 m), is located in the second subterranean of the North Wing of the building of Laboratories of the La Reina Nuclear Center in Santiago City, (3 meters under the ground). It is composed by 12 cm thickness walls of concrete, then successive layers of 2 mm of thickness with: lead, cadmium and copper, 1 cm of acrylic and finally 2 mm of wood. The measurement system is composed by: 2 detectors of NaI (Tl) of 8 x 3 inches (BICRON) that operate to 800 volts (+) and allow the detection of gamma emitters of high energy (>100 keV). It has the possibility of measurement fixes (thyroid) and route (whole body) using for it a pneumatic system that allows the displacement of the detectors on a central axis. It has two positions of location of the detectors, one of 90 degrees with respect to the central axis when the system is in rest or entrance retirement of patient and one of 45 degrees approximately when the measurement is made. For the calibration, two simulators were used: Thyroid simulator from the IRD (Brazil), and Whole Body, BOMAB simulator ( 133 Ba, 137 Cs and 60 Co) from the IAEA. 10 measurements of 300 seconds each one per geometry and different detector-patient distances were done: 20.0; 25.0; 30.0; 37.7 and 101.1 cm (considering high level incorporations). For the analysis of spectrum, software 'Genie 2000' and for the calculation of dose, program 'AIDE' obtained through ARCAL RLA/9/049 'Harmonization of Procedures of Internal Dosimetry', were used. To date, 300 measurements have been made and the results were used for the evaluation of the internal Dosimetry of the Professional Exposed Workers (PEW), but also to improve

Foreign criteria and programs

International Nuclear Information System (INIS)

Swinth, K.L.; Thompson, I.M.G.

1993-03-01

The concept of measurement quality assurance (MQA) as embodied in National Institute of Standards and Technology (NIST) programs is not generally used within European programs for testing or accreditation. Although the essential elements of quality control and quality assurance are in the European programs, the concept of testing the capability of the laboratory itself, in terms of its performance for the designated measurements, may not be included. Rather, the European programs use the concept of periodic calibration of laboratory reference standards against the next highest level of standards. Thus, they embody the concept of measurement traceability to appropriate primary standards. Within Europe a series of calibration accreditation programs has been established in the various countries tied together through a multilateral agreement. The radiation measurement programs are based on the International Organization for Standardization (ISO) 9000 series of standards. The purpose of this paper is to outline the overall operation of European Accreditation Programs in the radiation calibration and measurement areas. The operation of the radiation measurement programs of the National Measurement Accreditation Service (NAMAS) in the United Kingdom is described in detail along with other European programs. The manner in which these programs relate to individual dosimetry service programs is also described

Neutron personnel dosimetry

International Nuclear Information System (INIS)

Griffith, R.V.

1982-01-01

The measurement of neutron exposures to personnel is an issue that has received increased attention in the last few years. It is important to consider key aspects of the whole dosimetry system when developing dose estimates. This begins with selection of proper dosimeters and survey instruments, and extends through the calibration methods. One must match the spectral response and sensitivity of the dosimeter to the spectral characteristics of the neutron fields. Threshold detectors that are insensitive to large fractions of neutrons in the lower energy portion of reactor spectra should be avoided. Use of two or more detectors with responses that complement each other will improve measurement quality. It is important to understand the spectral response of survey instruments, so that spectra which result in significant overresponse do not lead to overestimation of dose. Calibration sources that do not match operational field spectra can contribute to highly erroneous results. In those situations, in-field calibration techniques should be employed. Although some detection developments have been made in recent years, a lot can be done with existing technology until fully satisfactory, long term solutions are obtained

Biophysical dosimetry using electron paramagnetic resonance in human tooth

International Nuclear Information System (INIS)

Khan, R.F.H.; Boreham, D.R.; Rink, W.J.

2002-01-01

Accidental dosimetry utilizing radiation induced paramagnetic species in biophysical tissues like teeth is a technique; that can measure the amount of radiation exposure to an individual. The major problem in implementing this technique at low doses is the presence of native organic signal, and various other artifacts produced as a result of sample processing. After a series of experimental trials, we developed an optimum set of rules, which uses high temperature ultrasonic treatment of enamel in KOH, multiple sample rotation during in-cavity measurement of natural and calibrated added irradiations, and dose construction using a backward extrapolation method. By using this we report the successful dose reconstruction in a few of our laboratory samples in 100 mGy range (76.29 ± 30.14) mGy with reasonably low uncertainty. Keywords: biophysical dosimetry, human tooth enamel, low dose measurements, accidental dosimetry (author)

Is gerontology ready for accreditation?

Science.gov (United States)

Haley, William E; Ferraro, Kenneth F; Montgomery, Rhonda J V

2012-01-01

The authors review widely accepted criteria for program accreditation and compare gerontology with well-established accredited fields including clinical psychology and social work. At present gerontology lacks many necessary elements for credible professional accreditation, including defined scope of practice, applied curriculum, faculty with applied professional credentials, and resources necessary to support professional credentialing review. Accreditation with weak requirements will be dismissed as "vanity" accreditation, and strict requirements will be impossible for many resource-poor programs to achieve, putting unaccredited programs at increased risk for elimination. Accreditation may be appropriate in the future, but it should be limited to professional or applied gerontology, perhaps for programs conferring bachelor's or master's degrees. Options other than accreditation to enhance professional skills and employability of gerontology graduates are discussed.

Study of film dosimetry for radiotherapy with Gafchromic-RTQ plates

International Nuclear Information System (INIS)

Diaz Moreno, Rogelio Manuel; Lara Mas, Elier; Alfonso Laguardia, Rodolfo

2009-01-01

Film dosimetry allows quality control processes (CC) for advanced radiotherapy treatments, not achievable with other types of systems dosimetry, as is the determination of two-dimensional dose distribution provided with the planned treatment in selected planes. The aim of this work was to establish the possibilities of making this type of CC with the means available in the INOR. Plates were used radiochromic Gafchromic-RTQ, for quality control, which irradiated with Elekta Precise linear accelerator, according to the test planning developed in the treatment planning system Precise Plan. Were used as image processing software the Mephysto mc2, PTW, and routines scheduled at home on Matlab. Was prepared calibration curve Dose-response for these plates, and applied this calibration curve at other boards with known radiation dose to estimate proximity of the dose obtained through calibration. Other tests were performed to determine the conditions of repeatability and optimal parameters of the process. Conditions were established that are obtained more reliable , the which are lower than those reported Gafchromic-EBT plates, especially designed quantitative dosimetric purposes, but in certain ranges allow evaluate the of a plan with an acceptable degree of approximation. (author)

SU-D-BRC-04: Development of Proton Tissue Equivalent Materials for Calibration and Dosimetry Studies

Energy Technology Data Exchange (ETDEWEB)

Olguin, E [Gainesville, FL (United States); Flampouri, S [University of Florida Proton Therapy Institute, Jacksonville, FL (United States); Lipnharski, I [University of Florida, Gainesville, FL (United States); Bolch, W [University Florida, Gainesville, FL (United States)

2016-06-15

Purpose: To develop new proton tissue equivalent materials (PTEM), urethane and fiberglass based, for proton therapy calibration and dosimetry studies. Existing tissue equivalent plastics are applicable only for x-rays because they focus on matching mass attenuation coefficients. This study aims to create new plastics that match mass stopping powers for proton therapy applications instead. Methods: New PTEMs were constructed using urethane and fiberglass resin materials for soft, fat, bone, and lung tissue. The stoichiometric analysis method was first used to determine the elemental composition of each unknown constituent. New initial formulae were then developed for each of the 4 PTEMs using the new elemental compositions and various additives. Samples of each plastic were then created and exposed to a well defined proton beam at the UF Health Proton Therapy Institute (UFHPTI) to validate its mass stopping power. Results: The stoichiometric analysis method revealed the elemental composition of the 3 components used in creating the PTEMs. These urethane and fiberglass based resins were combined with additives such as calcium carbonate, aluminum hydroxide, and phenolic micro spheres to achieve the desired mass stopping powers and densities. Validation at the UFHPTI revealed adjustments had to be made to the formulae, but the plastics eventually had the desired properties after a few iterations. The mass stopping power, density, and Hounsfield Unit of each of the 4 PTEMs were within acceptable tolerances. Conclusion: Four proton tissue equivalent plastics were developed: soft, fat, bone, and lung tissue. These plastics match each of the corresponding tissue’s mass stopping power, density, and Hounsfield Unit, meaning they are truly tissue equivalent for proton therapy applications. They can now be used to calibrate proton therapy treatment planning systems, improve range uncertainties, validate proton therapy Monte Carlo simulations, and assess in-field and out

Dosimetry characterization of the commercial CaF2 for beta radiation of 90Sr + 90Y

International Nuclear Information System (INIS)

Oliveira, Mercia L.; Caldas, Linda V.E.

2003-01-01

This work studies the dosimetric characteristics of the CaF 2 commercial dosimetry for detection of 90 Sr + 90 Y beta radiation for using in the calibration of flat and concave appliers. Were determined the repetitiousness and linearity of answers of the samples, and their calibration curves

Air kerma standardization for diagnostic radiology, and requirements proposal for calibration laboratories

International Nuclear Information System (INIS)

Ramos, Manoel Mattos Oliveira

2009-01-01

The demand for calibration services and quality control in diagnostic radiology has grown in the country since the publication of the governmental regulation 453, issued by the Ministry of Health in 1998. At that time, to produce results facing the new legislation, many laboratories used different standards and radiation qualities, some of which could be inadequate. The international standards neither supplied consistent radiation qualities and standardization for the different types of equipment available. This situation changed with the publication of the new edition of the IEC 61267 standard, published in 2005. A metrology network was created, but it is not yet accredited by the accreditation organism of the country, INMETRO. The objective of this work was to implement the standardization of the air kerma for the un attenuated qualities (RQR) of IEC 61267, and to develop a requirement proposal for instruments calibration laboratories. Results of interlaboratory comparisons demonstrate that the quantity is standardized and internationally traceable. A laboratory requirement proposal was finalized and it shall be submitted to INMETRO to be used as auxiliary normative document in laboratory accreditation. (author)

Neutron dosimetry in containment of a pressurized water reactor utilizing the Panasonic UD-802 dosimetry system

International Nuclear Information System (INIS)

Kralick, S.C.

1984-01-01

The Panasonic UD-802 dosimeter was evaluated as a potential neutron dosimeter for use in containment of a PWR. The Panasonic UD-802 dosimeter, although designed as a beta and gamma dosimeter, is also sensitive to neutrons. UD-802 dosimeters were mounted on polyethylene phantoms and irradiated to known doses at selected locations in containment. The known neutron dose equivalents were determined based on remmeter dose rate measurements and stay times. The thermoluminescent response of the dosimeters and the known neutron dose equivalents were used to obtain a calibration factor at each location. The average calibration factor was 3.7 (unit of dosimeter response per mrem) and all calibration factors were within +-30% of this mean value. The dosimeter distance from the phantom was found to have minimal effect on the response but the system was directionally dependent, necessitating a correction in the calibration factor. The minimum significant dosimeter response was determined independent of any calibration factor. The minimum significant response of the UD-802 to neutrons is a function of the corresponding gamma exposure rate. It is concluded that the Panasonic UD-802 dosimeter can be used for neutron dosimetry in PWR containment

Dosimetry study comparing NCS report-2 versus IAEA TRS-398 protocol for high energy photon beams

International Nuclear Information System (INIS)

Attalaa, E.M.; Khaled, N.E.; Abou Elenein, H.S.; Elsayed, A.A.

2005-01-01

In this work a dosimetry study is presented in which the results of absorbed dose determined at reference condition according to the IAEA TRS-398 protocol and the NCS report-2 are compared. The IAEA TRS-398 protocol for absorbed dose calibration is based on ionization chamber having absorbed dose to water calibration factor N d w, while the NCS-2 dosimetry report for absorbed dose calibration is based on an ionization chamber having air- kerma calibration factor N k . This study shows that the absorbed dose which is calculated with The IAEA TRS-398 formalisms is higher than that calculated with NCS report-2 formalisms within range from 0.4 to 0.9% in cobalt-60 beam as sensed by different ionization chambers, and from 0.2 to 1.1% for different higher energy photon beams of 6, 8 and 18 MV. The chambers used are PTW 30001, 30004, and NE-2571; which have calibration factors N k and N d w traceable to the BIPM (Bureau International des Poids et Mesures)

Automated Calibration of Dosimeters for Diagnostic Radiology

International Nuclear Information System (INIS)

Romero Acosta, A.; Gutierrez Lores, S.

2015-01-01

Calibration of dosimeters for diagnostic radiology includes current and charge measurements, which are often repetitive. However, these measurements are usually done using modern electrometers, which are equipped with an RS-232 interface that enables instrument control from a computer. This paper presents an automated system aimed to the measurements for the calibration of dosimeters used in diagnostic radiology. A software application was developed, in order to achieve the acquisition of the electric charge readings, measured values of the monitor chamber, calculation of the calibration coefficient and issue of a calibration certificate. A primary data record file is filled and stored in the computer hard disk. The calibration method used was calibration by substitution. With this system, a better control over the calibration process is achieved and the need for human intervention is reduced. the automated system will be used in the calibration of dosimeters for diagnostic radiology at the Cuban Secondary Standard Dosimetry Laboratory of the Center for Radiation Protection and Hygiene. (Author)

Fiber-coupled Al_2O_3:C radioluminescence dosimetry for total body irradiations

International Nuclear Information System (INIS)

Buranurak, S.; Andersen, C.E.

2016-01-01

In vivo dosimetry can be important and relevant in radiotherapy, especially when commissioning new treatment techniques at hospitals. This study investigates the potential use of fiber-coupled radioluminescence (RL) dosimetry based on Al_2O_3:C or organic plastic scintillators for this purpose in the context of Total Body Irradiations (TBIs) where patients are treated with large fields of 6 or 18 MV photons at an extended source-to-surface distance (SSD). The study shows that Al_2O_3:C dosimetry using the saturated-RL protocol may be suitable for real-time in vivo dosimetry during TBI treatments from the perspective of the good agreement with alanine dosimetry and other critical phantom tests, including the ability to cope with the large stem signal experienced during TBI treatments at extended SSD. In contrast, the chromatic stem removal technique often used for organic plastic scintillators did not work well in large fields with the tested calibration procedure and instrumentation. An apparent dose-rate effect discussed in a previous study of the RL properties of Al_2O_3:C (Andersen et al., 2011) was found to have resulted from an overlooked dead time problem in the counting system, and this potential caveat can therefore be removed from the list of potential problems associated with fiber-coupled Al_2O_3:C dosimetry using the saturated-RL protocol. This further has implications for TBI dosimetry using the RL Al_2O_3:C system due to large dose-rate differences between calibrations at the iso-center and in vivo measurements at extended source-to-surface distances. - Highlights: • Fiber-coupled dosimetry can be used for measurements during total body irradiations. • An apparent dose-effect associated with radioluminescence from Al2O3:C was resolved. • The gated-counting stem removal procedure worked well for Al2O3:C in pulsed accelerator beams. • The chromatic stem removal procedure did not work well with the tested instrumentation and organic plastic

A fast dual wavelength laser beam fluid-less optical CT scanner for radiotherapy 3D gel dosimetry II: dosimetric performance

Science.gov (United States)

Ramm, Daniel

2018-02-01

New clinical radiotherapy dosimetry systems need comprehensive demonstration of measurement quality. Practicality and reliability are other important aspects for clinical dosimeters. In this work the performance of an optical CT scanner for true 3D dosimetry is assessed using a radiochromic gel dosimeter. The fluid-less scanner utilised dual lasers to avoid the necessity for pre-irradiation scans and give greater robustness of image quality, enhancing practicality. Calibration methods using both cuvettes and reconstructed volumes were developed. Dosimetric accuracy was similar for dual and single wavelength measurements, except that cuvette calibration reliability was reduced for dual wavelength without pre-irradiation scanning. Detailed performance parameters were specified for the dosimetry system indicating the suitability for clinical use. The most significant limitations of the system were due to the gel dosimeter rather than the optical CT scanner. Quality assurance guidelines were developed to maintain dosimetry system performance in routine use.

Topics in radiation dosimetry radiation dosimetry

CERN Document Server

1972-01-01

Radiation Dosimetry, Supplement 1: Topics in Radiation Dosimetry covers instruments and techniques in dealing with special dosimetry problems. The book discusses thermoluminescence dosimetry in archeological dating; dosimetric applications of track etching; vacuum chambers of radiation measurement. The text also describes wall-less detectors in microdosimetry; dosimetry of low-energy X-rays; and the theory and general applicability of the gamma-ray theory of track effects to various systems. Dose equivalent determinations in neutron fields by means of moderator techniques; as well as developm

Does accreditation stimulate change? A study of the impact of the accreditation process on Canadian healthcare organizations

Directory of Open Access Journals (Sweden)

Shabah Abdo

2010-04-01

Full Text Available Abstract Background One way to improve quality and safety in healthcare organizations (HCOs is through accreditation. Accreditation is a rigorous external evaluation process that comprises self-assessment against a given set of standards, an on-site survey followed by a report with or without recommendations, and the award or refusal of accreditation status. This study evaluates how the accreditation process helps introduce organizational changes that enhance the quality and safety of care. Methods We used an embedded multiple case study design to explore organizational characteristics and identify changes linked to the accreditation process. We employed a theoretical framework to analyze various elements and for each case, we interviewed top managers, conducted focus groups with staff directly involved in the accreditation process, and analyzed self-assessment reports, accreditation reports and other case-related documents. Results The context in which accreditation took place, including the organizational context, influenced the type of change dynamics that occurred in HCOs. Furthermore, while accreditation itself was not necessarily the element that initiated change, the accreditation process was a highly effective tool for (i accelerating integration and stimulating a spirit of cooperation in newly merged HCOs; (ii helping to introduce continuous quality improvement programs to newly accredited or not-yet-accredited organizations; (iii creating new leadership for quality improvement initiatives; (iv increasing social capital by giving staff the opportunity to develop relationships; and (v fostering links between HCOs and other stakeholders. The study also found that HCOs' motivation to introduce accreditation-related changes dwindled over time. Conclusions We conclude that the accreditation process is an effective leitmotiv for the introduction of change but is nonetheless subject to a learning cycle and a learning curve. Institutions invest

The United Kingdom's radiotherapy dosimetry audit network

International Nuclear Information System (INIS)

Thwaites, D.I.; Allahverdi, M.; Powley, S.K.; Nisbet, A.

2003-01-01

The first comprehensive national dosimetry intercomparison in the United Kingdom involving all UK radiotherapy centres was carried out in the late 1980s. Out of this a regular radiotherapy dosimetry audit network evolved in the early 1990s. The network is co-ordinated by the Institute of Physics and Engineering in Medicine and comprises eight co-operative regional groups. Audits are based on site visits using ionization chambers and epoxy resin water substitute phantoms. The basic audit methodology and phantom design follows that of the original national intercomparison exercise. However, most of the groups have evolved more complex methods, to extend the audit scope to include other parameters, other parts of the radiotherapy process and other treatment modalities. A number of the groups have developed phantoms to simulate various clinical treatment situations, enabling the sharing of phantoms and expertise between groups, but retaining a common base. Besides megavoltage external beam photon dosimetry, a number of the groups have also included the audit of kilovoltage X ray beams, electron beams and brachytherapy dosimetry. The National Physical Laboratory is involved in the network and carries out basic beam calibration audits to link the groups. The network is described and the methods and results are illustrated using the Scottish+ group as an example. (author)

CDC/NACCHO Accreditation Support Initiative: advancing readiness for local and tribal health department accreditation.

Science.gov (United States)

Monteiro, Erinn; Fisher, Jessica Solomon; Daub, Teresa; Zamperetti, Michelle Chuk

2014-01-01

Health departments have various unique needs that must be addressed in preparing for national accreditation. These needs require time and resources, shortages that many health departments face. The Accreditation Support Initiative's goal was to test the assumption that even small amounts of dedicated funding can help health departments make important progress in their readiness to apply for and achieve accreditation. Participating sites' scopes of work were unique to the needs of each site and based on the proposed activities outlined in their applications. Deliverables and various sources of data were collected from sites throughout the project period (December 2011-May 2012). Awardees included 1 tribal and 12 local health departments, as well as 5 organizations supporting the readiness of local and tribal health departments. Sites dedicated their funding toward staff time, accreditation fees, completion of documentation, and other accreditation readiness needs and produced a number of deliverables and example documents. All sites indicated that they made accreditation readiness gains that would not have occurred without this funding. Preliminary evaluation data from the first year of the Accreditation Support Initiative indicate that flexible funding arrangements may be an effective way to increase health departments' accreditation readiness.

Strengthening organizational performance through accreditation research-a framework for twelve interrelated studies: the ACCREDIT project study protocol

Directory of Open Access Journals (Sweden)

Pope Catherine

2011-10-01

Full Text Available Abstract Background Service accreditation is a structured process of recognising and promoting performance and adherence to standards. Typically, accreditation agencies either receive standards from an authorized body or develop new and upgrade existing standards through research and expert views. They then apply standards, criteria and performance indicators, testing their effects, and monitoring compliance with them. The accreditation process has been widely adopted. The international investments in accreditation are considerable. However, reliable evidence of its efficiency or effectiveness in achieving organizational improvements is sparse and the value of accreditation in cost-benefit terms has yet to be demonstrated. Although some evidence suggests that accreditation promotes the improvement and standardization of care, there have been calls to strengthen its research base. In response, the ACCREDIT (Accreditation Collaborative for the Conduct of Research, Evaluation and Designated Investigations through Teamwork project has been established to evaluate the effectiveness of Australian accreditation in achieving its goals. ACCREDIT is a partnership of key researchers, policymakers and agencies. Findings We present the framework for our studies in accreditation. Four specific aims of the ACCREDIT project, which will direct our findings, are to: (i evaluate current accreditation processes; (ii analyse the costs and benefits of accreditation; (iii improve future accreditation via evidence; and (iv develop and apply new standards of consumer involvement in accreditation. These will be addressed through 12 interrelated studies designed to examine specific issues identified as a high priority. Novel techniques, a mix of qualitative and quantitative methods, and randomized designs relevant for health-care research have been developed. These methods allow us to circumvent the fragmented and incommensurate findings that can be generated in small

Strengthening organizational performance through accreditation research-a framework for twelve interrelated studies: the ACCREDIT project study protocol.

Science.gov (United States)

Braithwaite, Jeffrey; Westbrook, Johanna; Johnston, Brian; Clark, Stephen; Brandon, Mark; Banks, Margaret; Hughes, Clifford; Greenfield, David; Pawsey, Marjorie; Corbett, Angus; Georgiou, Andrew; Callen, Joanne; Ovretveit, John; Pope, Catherine; Suñol, Rosa; Shaw, Charles; Debono, Deborah; Westbrook, Mary; Hinchcliff, Reece; Moldovan, Max

2011-10-09

Service accreditation is a structured process of recognising and promoting performance and adherence to standards. Typically, accreditation agencies either receive standards from an authorized body or develop new and upgrade existing standards through research and expert views. They then apply standards, criteria and performance indicators, testing their effects, and monitoring compliance with them. The accreditation process has been widely adopted. The international investments in accreditation are considerable. However, reliable evidence of its efficiency or effectiveness in achieving organizational improvements is sparse and the value of accreditation in cost-benefit terms has yet to be demonstrated. Although some evidence suggests that accreditation promotes the improvement and standardization of care, there have been calls to strengthen its research base.In response, the ACCREDIT (Accreditation Collaborative for the Conduct of Research, Evaluation and Designated Investigations through Teamwork) project has been established to evaluate the effectiveness of Australian accreditation in achieving its goals. ACCREDIT is a partnership of key researchers, policymakers and agencies. We present the framework for our studies in accreditation. Four specific aims of the ACCREDIT project, which will direct our findings, are to: (i) evaluate current accreditation processes; (ii) analyse the costs and benefits of accreditation; (iii) improve future accreditation via evidence; and (iv) develop and apply new standards of consumer involvement in accreditation. These will be addressed through 12 interrelated studies designed to examine specific issues identified as a high priority. Novel techniques, a mix of qualitative and quantitative methods, and randomized designs relevant for health-care research have been developed. These methods allow us to circumvent the fragmented and incommensurate findings that can be generated in small-scale, project-based studies. The overall

Accuracy and efficiency of published film dosimetry techniques using a flat-bed scanner and EBT3 film.

Science.gov (United States)

Spelleken, E; Crowe, S B; Sutherland, B; Challens, C; Kairn, T

2018-03-01

Gafchromic EBT3 film is widely used for patient specific quality assurance of complex treatment plans. Film dosimetry techniques commonly involve the use of transmission scanning to produce TIFF files, which are analysed using a non-linear calibration relationship between the dose and red channel net optical density (netOD). Numerous film calibration techniques featured in the literature have not been independently verified or evaluated. A range of previously published film dosimetry techniques were re-evaluated, to identify whether these methods produce better results than the commonly-used non-linear, netOD method. EBT3 film was irradiated at calibration doses between 0 and 4000 cGy and 25 pieces of film were irradiated at 200 cGy to evaluate uniformity. The film was scanned using two different scanners: The Epson Perfection V800 and the Epson Expression 10000XL. Calibration curves, uncertainty in the fit of the curve, overall uncertainty and uniformity were calculated following the methods described by the different calibration techniques. It was found that protocols based on a conventional film dosimetry technique produced results that were accurate and uniform to within 1%, while some of the unconventional techniques produced much higher uncertainties (> 25% for some techniques). Some of the uncommon methods produced reliable results when irradiated to the standard treatment doses (film analysis technique which uses transmission scanning, red colour channel analysis, netOD and a non-linear calibration curve for measuring doses up to 4000 cGy when using EBT3 film.

Radiation Dosimetry for Quality Control of Food Preservation and Disinfestation

DEFF Research Database (Denmark)

McLaughlin, W.L.; Miller, Arne; Uribe, R.M.

1983-01-01

In the use of x and gamma rays and scanned electron beams to extend the shelf life of food by delay of sprouting and ripening, killing of microbes, and control of insect population, quality assurance is provided by standardized radiation dosimetry. By strategic placement of calibrated dosimeters...

In vivo dosimetry with thermoluminescent dosimeters in radiotherapy: entrance and exit doses

International Nuclear Information System (INIS)

Alves, C.; Lopes, M.C.

2000-01-01

In vivo dosimetry, by entrance and exit dose measurements, is a vital part of a radiotherapy quality assurance program. The uncertainty associated with dose delivery is internationally accepted to be within 5% or inferior depending on the tumor pathology. Thermoluminescent dosimetry is one of the dosimetric techniques used to verify the agreement between delivered and prescribed doses. Nevertheless, it requires a very accurate calibration methodology. We have used LiF chips (4.5 mm diameter and 0.8 mm thick) calibrated towards a PTW ionization chamber of 0.3 cc, in three photon energies: Co-60, 4 and 6 MeV. The TLD reader used was a Rialto 688 from NE Technology and the annealing oven the Eurotherm type 815. The calibration methodology relies on the experimental determination of individual correction factors and on a correction factor derived from a control group of dosimeters. The exit and entrance dose measurements are performed in quite different situations. To be able to achieve those two quantities with TLD, these should be independently calibrated according to the measurement conditions. Alternatively, we can use a single calibration, in entrance dose, and convert the result to the exit dose value by introducing some correction factors. These corrections are related to the different measurement depths and to the different backscattering contributions. We have proved that within an acceptable error we can perform a single calibration and adopt the correction factors which are energy and field size dependent. (author)

Dosimetry of ionizing radiation. Fundamentals and applications. Dosimetrie ionisierender Strahlen. Grundlagen und Anwendungen

Energy Technology Data Exchange (ETDEWEB)

Reich, H [ed.

1990-01-01

In the first chapter of the book, a brief description is given of the historical development of dosimetry, of its objectives and special role within the context of general physical metrology, followed by detailed explanations of the physical fundamentals of this science: the sources and fields of radiation, interactions between radiation and matter as well as radiation detectors. The terminology and units of measurement used in dosimetry are explained in a separate chapter. Chapters 7 and 8, which outline the various theoretical and experimental methods of dose determination, are the most essential contributions to this volume. Chapter 9 deals with the ways in which dosimetry is used in special cases in radiotherapy as well as in the measurement of very small or very large doses. Chapter 10 gives a survey of recently introduced units of measurements and methods to calculate the body dose with reference to the particular type of exposure used. Appendix A contains tables of measuring units, physical constants and measuring techniques along with at-a-glance information on the legal regulations concerning the calibration of dosimeters. Appendix B gives practical guidance on the handling of hardware-related inaccuracies of measurement in dose determination procedures and appendix C embraces 22 pages of tables showing data on radiation physics. (orig./HP) With 150 figs., 50 tabs. in the text, and annex with tables.

ISO/IEC 17025 laboratory accreditation of NRC Acoustical Standards Program

Science.gov (United States)

Wong, George S. K.; Wu, Lixue; Hanes, Peter; Ohm, Won-Suk

2004-05-01

Experience gained during the external accreditation of the Acoustical Standards Program at the Institute for National Measurement Standards of the National Research Council is discussed. Some highlights include the preparation of documents for calibration procedures, control documents with attention to reducing future paper work and the need to maintain documentation or paper trails to satisfy the external assessors. General recommendations will be given for laboratories that are contemplating an external audit in accordance to the requirements of ISO/IEC 17025.

[Accreditation of medical laboratories].

Science.gov (United States)

Horváth, Andrea Rita; Ring, Rózsa; Fehér, Miklós; Mikó, Tivadar

2003-07-27

In Hungary, the National Accreditation Body was established by government in 1995 as an independent, non-profit organization, and has exclusive rights to accredit, amongst others, medical laboratories. The National Accreditation Body has two Specialist Advisory Committees in the health care sector. One is the Health Care Specialist Advisory Committee that accredits certifying bodies, which deal with certification of hospitals. The other Specialist Advisory Committee for Medical Laboratories is directly involved in accrediting medical laboratory services of health care institutions. The Specialist Advisory Committee for Medical Laboratories is a multidisciplinary peer review group of experts from all disciplines of in vitro diagnostics, i.e. laboratory medicine, microbiology, histopathology and blood banking. At present, the only published International Standard applicable to laboratories is ISO/IEC 17025:1999. Work has been in progress on the official approval of the new ISO 15189 standard, specific to medical laboratories. Until the official approval of the International Standard ISO 15189, as accreditation standard, the Hungarian National Accreditation Body has decided to progress with accreditation by formulating explanatory notes to the ISO/IEC 17025:1999 document, using ISO/FDIS 15189:2000, the European EC4 criteria and CPA (UK) Ltd accreditation standards as guidelines. This harmonized guideline provides 'explanations' that facilitate the application of ISO/IEC 17025:1999 to medical laboratories, and can be used as a checklist for the verification of compliance during the onsite assessment of the laboratory. The harmonized guideline adapted the process model of ISO 9001:2000 to rearrange the main clauses of ISO/IEC 17025:1999. This rearrangement does not only make the guideline compliant with ISO 9001:2000 but also improves understanding for those working in medical laboratories, and facilitates the training and education of laboratory staff. With the

Clinical dosimetry in diagnostic and interventional radiology

International Nuclear Information System (INIS)

Dimcheva, M.; Sergieva, S.; Jovanovska, A.

2012-01-01

Full text: Introduction: Diagnostic and interventional procedures involving x-rays are the most significant contributor to total population dose form man made sources of ionizing radiation. Purpose and aim: X-ray imaging generally covers a diverse range of examination types, many of which are increasing in frequency and technical complexity. Materials and methods: The European Directives 96/29 and 97/43 EURATOM stress the importance of accurate dosimetry and require calibration of all measuring equipment related to application of ionizing radiation in medicine. Results: The paper gives and overview of current system of dosimetry of ionizing radiations that is relevant for metrology and clinical applications. It also reflects recently achieved international harmonization in the field promoted by International Atomic Energy Agency (IAEA). Discussion: Objectives of clinical dose measurements in diagnostic and interventional radiology are multiple, as assessment of equipment performance, or assessment of risk emerging from use of ionizing radiation Conclusion: Therefore, from the clinical point of view, the requirements for dosimeters and procedures to assess dose to standard dosimetry phantoms and patients in clinical diverse modalities, as computed tomography are presented

Biodosimetry versus physical dosimetry for emergency dose assessment following large-scale radiological exposures

International Nuclear Information System (INIS)

McKeever, S.W.S.; Sholom, S.

2016-01-01

Existing data on intercomparisons involving biodosimetry or physical dosimetry methods are analyzed and the results interpreted regarding their efficacy in triage in emergency dosimetry following mass casualty radiological events. The biodosimetry technique examined is dicentric chromosome aberrations (DCA). The physical dosimetry techniques include electron paramagnetic resonance (EPR) of biological material (teeth) and physical material (smartphone screen glass), and optically stimulated luminescence (OSL) of electronic components (surface mount resistors) from mobile phones. Issues relating to calibration and interpretation of the data are discussed. An important conclusion of the analysis is that more research is critically needed to interpret the efficacy of the various methods. Included in this needed research are intercomparisons of the various methods in controlled experiments and the need to harmonize protocols. - Highlights: • Utility of bio- and physical dosimetry methods for emergency dosimetry triage. • Analysis of intercomparison data for different bio- and physical dosimetry methods. • The percentage of false positives and false negatives for a simulated IND event. • More research, especially intercomparisons, is required to reduce uncertainties.

Accreditation and radiation protection - the cost or smaller doses and reliable results

International Nuclear Information System (INIS)

Omahen, G.; Zdesar, U.

2011-01-01

Laboratories involved in the protection against radiation and therefore in the measurement of radioactivity, dose rate and contamination have always been tied to the quality of their measurements, particularly those that have performed measurements for nuclear power plants. However in the laboratories more than quality it was more important, that people are professional, that they are engaged in scientific work and know how to interpret the results. Very often these are things that do not go along with reviewing the measuring instruments and quality records. However customer requires measurement results that can be trusted. This is the purpose of the standard SIST EN ISO / IEC 17025 in which the requirements for testing and calibration laboratories are standardised. The standard in force since 1999. In some countries, requests for accreditation of testing laboratories according to SIST EN ISO / IEC 17025 is even in regulation. This request is for example in the Croatian and Slovenian regulations for laboratories involved in measuring the radioactivity, dose rate, contamination, or by checking the X-ray apparatus. Several laboratories have been accreditation for several years. From that experience we can conclude that customer gets reliable results from the accredited laboratories at relatively low cost. On the other side laboratory which his accredited has introduced a line of work and his laboratory, there are rules for equipment, personnel, training and all that eventually enhanced measurement expertise. With accreditation, it is much easier to compensate for the loss of workers due to pension or leaving the laboratory because every moment must always be in the laboratory at least two who know how to work on the method. Accreditation is not improving radiation protection or reducing Becquerel in the air. But at least we know how accurate mSv or Bq are and how small mSv and Bq can be measured. (author) [sr

Measuring Systems for Thermometer Calibration in Low-Temperature Range

Science.gov (United States)

Szmyrka-Grzebyk, A.; Lipiński, L.; Manuszkiewicz, H.; Kowal, A.; Grykałowska, A.; Jancewicz, D.

2011-12-01

The national temperature standard for the low-temperature range between 13.8033 K and 273.16 K has been established in Poland at the Institute of Low Temperature and Structure Research (INTiBS). The standard consists of sealed cells for realization of six fixed points of the International Temperature Scale of 1990 (ITS-90) in the low-temperature range, an adiabatic cryostat and Isotech water and mercury triple-point baths, capsule standard resistance thermometers (CSPRT), and AC and DC bridges with standard resistors for thermometers resistance measurements. INTiBS calibrates CSPRTs at the low-temperature fixed points with uncertainties less than 1 mK. In lower temperature range—between 2.5 K and about 25 K — rhodium-iron (RhFe) resistance thermometers are calibrated by comparison with a standard which participated in the EURAMET.T-K1.1 comparison. INTiBS offers a calibration service for industrial platinum resistance thermometers and for digital thermometers between 77 K and 273 K. These types of thermometers may be calibrated at INTiBS also in a higher temperature range up to 550°C. The Laboratory of Temperature Standard at INTiBS acquired an accreditation from the Polish Centre for Accreditation. A management system according to EN ISO/IEC 17025:2005 was established at the Laboratory and presented on EURAMET QSM Forum.

The 4th international comparison on EPR dosimetry with tooth enamel

Energy Technology Data Exchange (ETDEWEB)

Fattibene, P., E-mail: paola.fattibene@iss.it [Istituto Superiore di Sanita, Department of Technology and Health, Viale Regina Elena 299, I-00162 Rome (Italy); Wieser, A. [Helmholtz Zentrum Muenchen, Neuherberg D-85764 (Germany); Adolfsson, E. [Linkoeping University, SE-58185 Linkoeping (Sweden); Benevides, L.A. [Naval Dosimetry Center, Bethesda MD 20889-5600 (United States); Brai, M. [University of Palermo, I-90128 Palermo (Italy); Callens, F. [Ghent University, B-9000 Gent (Belgium); Chumak, V. [Research Center for Radiation Medicine AMS, 04050 Kiev (Ukraine); Ciesielski, B. [Medical University of Gdansk, 80-211 Gdansk (Poland); Della Monaca, S. [Istituto Superiore di Sanita, Department of Technology and Health, Viale Regina Elena 299, I-00162 Rome (Italy); Regina Elena Institute, I-00144 Rome (Italy); Emerich, K. [Medical University of Gdansk, 80-211 Gdansk (Poland); Department of Paediatric Dentistry, 80-208 Gdansk (Poland); Gustafsson, H. [Linkoeping University, SE-58185 Linkoeping (Sweden); Hirai, Y. [Radiation Effects Research Foundation, Minami-ku, Hiroshima 732-0815 (Japan); Hoshi, M. [Hiroshima University, Minami-ku, Hiroshima 734-8553 (Japan); Israelsson, A. [Linkoeping University, SE-58185 Linkoeping (Sweden); Ivannikov, A. [Medical Radiological Research Center, Obninsk, Kaluga region (Russian Federation); Ivanov, D. [Institute of Metal Physics, Yekaterinburg 620041 (Russian Federation); Kaminska, J. [Medical University of Gdansk, 80-211 Gdansk (Poland); Ke, Wu [Beijing Institute of Radiation Medicine, Beijing 100850 (China); Lund, E. [Linkoeping University, SE-58185 Linkoeping (Sweden); Marrale, M. [University of Palermo, I-90128 Palermo (Italy)

2011-09-15

This paper presents the results of the 4th International Comparison of in vitro electron paramagnetic resonance dosimetry with tooth enamel, where the performance parameters of tooth enamel dosimetry methods were compared among sixteen laboratories from all over the world. The participating laboratories were asked to determine a calibration curve with a set of tooth enamel powder samples provided by the organizers. Nine molar teeth extracted following medical indication from German donors and collected between 1997 and 2007 were prepared and irradiated at the Helmholtz Zentrum Muenchen. Five out of six samples were irradiated at 0.1, 0.2, 0.5, 1.0 and 1.5 Gy air kerma; and one unirradiated sample was kept as control. The doses delivered to the individual samples were unknown to the participants, who were asked to measure each sample nine times, and to report the EPR signal response, the mass of aliquots measured, and the parameters of EPR signal acquisition and signal evaluation. Critical dose and detection limit were calculated by the organizers on the basis of the calibration-curve parameters obtained at every laboratory. For calibration curves obtained by measuring every calibration sample three times, the mean value of the detection limit was 205 mGy, ranging from 56 to 649 mGy. The participants were also invited to provide the signal response and the nominal dose of their current dose calibration curve (wherever available), the critical dose and detection limit of which were also calculated by the organizers.

The international protocol for the dosimetry of external radiotherapy beams based on standards of absorbed dose to water

International Nuclear Information System (INIS)

Andreo, P.

2001-01-01

An International Code of Practice (CoP, or dosimetry protocol) for external beam radiotherapy dosimetry based on standards of absorbed dose to water has been published by the IAEA on behalf of IAEA, WHO, PAHO and ESTRO. The CoP provides a systematic and internationally unified approach for the determination of the absorbed dose to water in reference conditions with radiotherapy beams. The development of absorbed-dose-to-water standards for high-energy photons and electrons offers the possibility of reducing the uncertainty in the dosimetry of radiotherapy beams. Many laboratories already provide calibrations at the radiation quality of 60Co gamma-rays and some have extended calibrations to high-energy photon and electron beams. The dosimetry of kilovoltage x-rays, as well as that of proton and ion beams can also be based on these standards. Thus, a coherent dosimetry system based on the same formalism is achieved for practically all radiotherapy beams. The practical use of the CoP as simple. The document is formed by a set of different CoPs for each radiation type, which include detailed procedures and worksheets. All CoPs are based on ND,w chamber calibrations at a reference beam quality Qo, together with radiation beam quality correction factors kQ preferably measured directly for the user's chamber in a standards laboratory. Calculated values of kQ are provided together with their uncertainty estimates. Beam quality specifiers are 60Co, TPR20,10 (high-energy photons), R50 (electrons), HVL and kV (x-rays) and Rres (protons and ions) [es

Dosimetry study for electron beam irradiation in radiation processing

International Nuclear Information System (INIS)

Sunaga, Hiromi; Haruyama, Yasuyuki; Takizawa, Haruki; Kojima, Takuji; Yotsumoto, Keiichi

1995-01-01

For certain critical applications such as medical device sterilization and food irradiation, accurate calibration of electron energy and absorbed dose is required to assure the quality of irradiated products. To meet this requirement, TRCRE, JAERI has carried out research and development on high dose radiation dosimetry for electron beams in the energy range used in radiation processing (0.15 - 3.0 MeV). JAERI has developed a simultaneous electron beam energy and dosimeter calibration system that consist of a total absorption calorimeter, an electron current density meter, and a stacked thin-film dosimeter set. For low energy electrons, where it is important to measure the depth-dose profile in materials with high depth resolution, we studied the feasibility of a method using Gafchromic film dosimeters. This film, which has an 8-μm thick sensitive layer, is combined with a stepped array of absorber films of the same thickness to produce a high-resolution depth-dose profile on the Gafchromic film. The depth-dose profile obtained in this manner has about five times greater resolution than conventional radiochromic film dosimetry. (author)

The development of UK protocols for electron beam dosimetry

International Nuclear Information System (INIS)

Thwaites, D.I.

1995-01-01

The IPSM Electron Dosimetry Working Party has completed a new set of recommendations for clinical electron beam dosimetry to replace the 1985 Code of Practice and its 1992 addendum. The current approach takes account of the significant body of relevant work over the last ten years and adopts the best consistent set of physical data currently available. It is still an air-kerma based approach, but adopts the N D formalism. This means that single conversion/correction factors are no longer retained. The new Code of Practice is intended to provide a solid basis for clinical practice at present, and to allow confident assessment of the introduction of the direct absorbed dose calibration service for electrons, currently under development by NPL, when that is ready. The structure of the new Code is reviewed, with discussion of changes from the 1985 approach and of the physical data incorporated. In particular the changes for parallel plate chamber calibration and use are discussed. Points of similarity and difference to other international codes are noted and the doses measured using different codes are compared

Light-water-reactor pressure-vessel surveillance dosimetry using solid-state track recorders

International Nuclear Information System (INIS)

Ruddy, F.H.; Roberts, J.H.; Gold, R.; Preston, C.C.

1983-07-01

The accumulation of neutron dose by the pressure vessel of an operating nuclear power plant results in damage in the form of steel embrittlement. In order to ascertain the safe operating lifetime of the reactor pressure vessel, dosimetric measurements must be made to evaluate the neutron dose to the pressure vessel and relate this dose to the cumulative radiation damage. Advanced dosimetry techniques are being evaluated for surveillance of operating reactors. Solid-state track recorder (SSTR) techniques are included among these advanced dosimetry techniques. Described herein are low neutron fluence calibration and standardization measurements that are being carried out in pressure vessel mockup benchmark neutron fields in the USA, Belgium, and England. In addition, high fluence SSTR dosimetry capsules have been irradiated with metallurgical specimens in a pressure vessel mockup facility. The design and deployment of advances SSTR dosimetry capsules in operating power reactors are also described

On the calibration of radiotherapy dosemeters in Australia

International Nuclear Information System (INIS)

Huntley, R.; Kotler, L.; Webb, D.

2000-01-01

Full text: Dosemeters for external beam radiotherapy are calibrated in Australia by ARPANSA, against the national primary standards of exposure and absorbed dose. The primary standards are free air chambers for exposure at low and medium energy X-rays, a graphite cavity chamber for exposure at 60 Co, and a graphite calorimeter for absorbed dose at 60 Co and high energy (MV) X -rays. Radiotherapy dosemeters are calibrated against these standards using a well documented formalism to provide calibration factors suitable for use with dosimetry protocols. A dosemeter usually comprises an ionization chamber connected to an independent electrometer. These are calibrated separately if possible. A combined calibration factor is reported together with the electrometer calibration factor (sensitivity). The dosimetry protocol used in radiotherapy centres in Australia and New Zealand is currently the simplified version of the IAEA TRS277 protocol, published by the New Zealand NRL and recommended by the ACPSEM. This protocol requires the use of an exposure or air kerma calibration factor at 60 Co (Nx or Nk) to evaluate the absorbed dose to air calibration factor N D . The chamber is then placed in a water phantom with its centre displaced from the reference point by p eff . ARPANSA can also supply calibration factors in absorbed dose to water (N D,w ), as required as input to the new IAEA CoP. If an absorbed dose to water calibration factor is used by the radiotherapy centre, the chamber should be placed with its centre at the reference point in the water phantom. ARPANSA has for some years coordinated the participation of Australian radiotherapy centres in the IAEA TLD Quality Audit service. Note that this service does not represent a calibration and should not be referred to as such. The only calibration is that provided by ARPANSA for a reference dosemeter at each radiotherapy centre. As soon as the ANSTO SSDL is operational, calibrations of reference dosemeters will also be

Diode In-vivo Dosimetry for External Beam Radiotherapy: Patient Data Analysis

International Nuclear Information System (INIS)

Mrcela, I.; Bokulic, T.; Budanec, M; Froebe, A.; Soldic, Z.; Kusic, Z.

2008-01-01

In-vivo dosimetry is known as simple and reliable method for checking the final accuracy of the dose delivered in external radiotherapy making a supplement to the regular quality control. Entrance dose measurements in the beginning of the treatment assure detection of major errors that can affect the therapy outcome. Silicon diodes are often the detectors of choice for their ability of real time dose measurements and the simplicity of use. There are many publications describing the procedures for the implementation of in-vivo dosimetry. Routine in-vivo dosimetry has been introduced in our department after initial procedures including physical characterization, calibration and determination of correction factors for the detectors in use. This work presents patient data analysis with more than 700 field measurements taken in last 2 years period

Analysis of ISO/IEC 17025 for establishment of KOLAS (Korea Laboratory Accreditation Scheme) quality assurance system

International Nuclear Information System (INIS)

Nam, Ji Hee

2000-12-01

Besides one existent accredited lab, radioactive material chemical analysis lab, five test laboratories and two calibration labs are under plan to acquire the accreditation from KOLAS. But the current Quality Manual was developed according to ISO Guide 25 that was superceded by ISO/IEC 17025. Since it is tailored to the radioactive material chemical analysis lab, a number of requirements of the Manual are not applicable to the labs other than radioactive material chemical analysis lab. Through the analysis of ISO/IEC 17025, a model of quality system was established which is not only consistent with ISO/IEC 17025 but reflective of the KAERI's situation

Intercomparison of dispersed radiation readings among film dosimetry, electronic and OSL with X-rays for low dose

International Nuclear Information System (INIS)

Andisco, D.; Blanco, S.; Bourel, V.; Schmidt, L.; Di Risio, C.

2014-08-01

One of the personal dosimetry methods more used for several decades is the dosimetry type film, characterized to possess readings with certain margin of trust. Today other methods exist that many times are presupposed more reliable due to the nature of the detection like the electronic dosimeters or the OSL (Optically Stimulated Luminescence) dosimetry. With the purpose of comparing different methods and to can determining the existent differences among each method has been carried out an intercomparison assay. The different dosimeters have been exposed to dispersed radiation generated by a Hemodynamics equipment of the type -arch in C- and a dispersing system of the primary beam. Film dosimeters have been used; OSL (In Light), OSL (Nano Dots) and Electronic with the purpose of knowing and to valorize the existent differences among its readings. Always, the intercomparison exercises have demonstrated to be an useful tool when establishing the measurement capacity and the quality of the results emitted by the laboratories of personal dosimetry services. Also, this type of assays allows obtaining quality indicators of the laboratory performance and they are habitual part of the procedures for accreditation of the same ones. The Optically Stimulated Luminescence is a technology that has grown in Argentina so much in the area of personal dosimetry as in dosimetry in vivo (radiotherapy area). In this intercomparison study, the answers corresponding to each technology were looked for oneself irradiation of the disperse type, that is to say, of very low energy. (Author)

Measurement of absorbed doses near interfaces, and dose mapping using gas chromic dosimetry media. Vol. 2

Energy Technology Data Exchange (ETDEWEB)

Abdel-Rehim, F; Said, F I.A.; Abdel-Fattah, A A [National Centre for Radiation Research and Technology, Atomic Energy Athority, P.O.Box 29 Nasr City, Cairo (Egypt)

1996-03-01

Gas chromic dosimetry media is a thin-coated film which has advantages for high-dose radiation dosimetry, and produces high-resolution radiation image for gamma radiation. Therefore, these films were calibrated for the dose range 0.1-50 kGy in terms of increase in absorbance at 600 nm, 400 nm; increase in the area of the absorption spectra in the ranges 395-405 nm and 320-450 nm wave length as a function of absorbed dose in water. The calibrated films were used for measurement of absorbed doses close to metal interface, and dose mapping of the radiation field inside product box during a run for sterilizing surgical gloves at the mega-gamma irradiation facility.7 figs.

Accreditation: a cultural control strategy.

Science.gov (United States)

Paccioni, André; Sicotte, Claude; Champagne, François

2008-01-01

The purpose of this paper is to describe and understand the effects of the accreditation process on organizational control and quality management practices in two Quebec primary-care health organizations. A multiple-case longitudinal study was conducted taking a mixed qualitative/quantitative approach. An analytical model was developed of the effects of the accreditation process on the type of organizational control exercised and the quality management practices implemented. The data were collected through group interviews, semi-directed interviews of key informers, non-participant observations, a review of the literature, and structured questionnaires distributed to all the employees working in both institutions. The accreditation process has fostered the implementation of consultation mechanisms in self-assessment teams. Improving assessments of client satisfaction was identified as a prime objective but, in terms of the values promoted in organizations, accreditation has little effect on the perceptions of employees not directly involved in the process. As long as not all staff members have integrated the basis for accreditation and its outcomes, the accreditation process appears to remain an external, bureaucratic control instrument. This study provides a theoretical model for understanding organizational changes brought about by accreditation of primary services. Through self-assessment of professional values and standards, accreditation may foster better quality management practices.

Clinical Psychology Training: Accreditation and Beyond.

Science.gov (United States)

Levenson, Robert W

2017-05-08

Beginning with efforts in the late 1940s to ensure that clinical psychologists were adequately trained to meet the mental health needs of the veterans of World War II, the accreditation of clinical psychologists has largely been the province of the Commission on Accreditation of the American Psychological Association. However, in 2008 the Psychological Clinical Science Accreditation System began accrediting doctoral programs that adhere to the clinical science training model. This review discusses the goals of accreditation and the history of the accreditation of graduate programs in clinical psychology, and provides an overview of the evaluation procedures used by these two systems. Accreditation is viewed against the backdrop of the slow rate of progress in reducing the burden of mental illness and the changes in clinical psychology training that might help improve this situation. The review concludes with a set of five recommendations for improving accreditation.

CT head-scan dosimetry in an anthropomorphic phantom and associated measurement of ACR accreditation-phantom imaging metrics under clinically representative scan conditions

Energy Technology Data Exchange (ETDEWEB)

Brunner, Claudia C.; Stern, Stanley H.; Chakrabarti, Kish [U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993 (United States); Minniti, Ronaldo [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899 (United States); Parry, Marie I. [Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, Maryland 20889 (United States); Skopec, Marlene [National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892 (United States)

2013-08-15

Purpose: To measure radiation absorbed dose and its distribution in an anthropomorphic head phantom under clinically representative scan conditions in three widely used computed tomography (CT) scanners, and to relate those dose values to metrics such as high-contrast resolution, noise, and contrast-to-noise ratio (CNR) in the American College of Radiology CT accreditation phantom.Methods: By inserting optically stimulated luminescence dosimeters (OSLDs) in the head of an anthropomorphic phantom specially developed for CT dosimetry (University of Florida, Gainesville), we measured dose with three commonly used scanners (GE Discovery CT750 HD, Siemens Definition, Philips Brilliance 64) at two different clinical sites (Walter Reed National Military Medical Center, National Institutes of Health). The scanners were set to operate with the same data-acquisition and image-reconstruction protocols as used clinically for typical head scans, respective of the practices of each facility for each scanner. We also analyzed images of the ACR CT accreditation phantom with the corresponding protocols. While the Siemens Definition and the Philips Brilliance protocols utilized only conventional, filtered back-projection (FBP) image-reconstruction methods, the GE Discovery also employed its particular version of an adaptive statistical iterative reconstruction (ASIR) algorithm that can be blended in desired proportions with the FBP algorithm. We did an objective image-metrics analysis evaluating the modulation transfer function (MTF), noise power spectrum (NPS), and CNR for images reconstructed with FBP. For images reconstructed with ASIR, we only analyzed the CNR, since MTF and NPS results are expected to depend on the object for iterative reconstruction algorithms.Results: The OSLD measurements showed that the Siemens Definition and the Philips Brilliance scanners (located at two different clinical facilities) yield average absorbed doses in tissue of 42.6 and 43.1 m

A feasibility study using radiochromic films for fast neutron 2D passive dosimetry

International Nuclear Information System (INIS)

Brady, Samuel L; Fallin, Brent; Gunasingha, Rathnayaka; Yoshizumi, Terry T; Howell, Calvin R; Crowell, Alexander S; Tonchev, Anton P; Dewhirst, Mark W

2010-01-01

The objective of this paper is threefold: (1) to establish sensitivity of XRQA and EBT radiochromic films to fast neutron exposure; (2) to develop a film response to radiation dose calibration curve and (3) to investigate a two-dimensional (2D) film dosimetry technique for use in establishing an experimental setup for a radiobiological irradiation of mice and to assess the dose to the mice in this setup. The films were exposed to a 10 MeV neutron beam via the 2 H(d,n) 3 He reaction. The XRQA film response was a factor of 1.39 greater than EBT film response to the 10 MeV neutron beam when exposed to a neutron dose of 165 cGy. A film response-to-soft tissue dose calibration function was established over a range of 0-10 Gy and had a goodness of fit of 0.9926 with the calibration data. The 2D film dosimetry technique estimated the neutron dose to the mice by measuring the dose using a mouse phantom and by placing a piece of film on the exterior of the experimental mouse setup. The film results were benchmarked using Monte Carlo and aluminum (Al) foil activation measurements. The radiochromic film, Monte Carlo and Al foil dose measurements were strongly correlated, and the film within the mouse phantom agreed to better than 7% of the externally mounted films. These results demonstrated the potential application of radiochromic films for passive 2D neutron dosimetry.

Comparison of theoretical and experimental determinations of calibration factors for cylindrical and parallel plates ionization chambers

International Nuclear Information System (INIS)

Vallejos, Matias; Montano, Gustavo A.; Stefanic, Amalia; Saravi, Margarita

2009-01-01

The Ionizing Radiation Dosimetry Section of CNEA is the National Laboratory of Dosimeter Reference, having been designated by the National Institute of Industrial Technology (INTI, deposit taker by Law 19,511/72 of the national standards for metrology) for the safekeeping and operation of the national standards for dosimetry (Agreement INTI - CNEA, February 2004). From their creation, the CRRD provides, among other services, the calibration of dosemeters used in radiotherapy, in terms of Kerma in air, and since year 2002 provides calibration in terms of absorbed dose in water. In this work, those elements appear whereupon it counts the laboratory and that they tend to consolidate the securing of the quality of the results obtained in the calibrations of dosemeters. (author)

Dosimetry for electron beam application

International Nuclear Information System (INIS)

Miller, A.

1983-12-01

This report describes two aspects of electron beam dosimetry, on one hand development of film dosimeters and measurements of their properties, and on the other hand development of calorimeters for calibration of routine dosimeters, e.g. thin films. Two types of radiochromic thin film dosimeters have been developed in this department, and the properties of these and commercially available dosimeters have been measured and found to be comparable. Calorimeters which are in use for routine measurements, are being investigated with reference to their application as standardizing instruments, and new calorimeters are being developed. (author)

Characterization of the materials used in the construction of a physical phantom for calibration of 18F-FDG internal dosimetry system

International Nuclear Information System (INIS)

Vital, Katia D.; Mendes, Bruno M.; Fonseca, Telma C.F.; Silva, Teógenes A. da

2017-01-01

The Internal Dosimetry Laboratory (LDI) of the Nuclear Technology Development Center (CDTN) in Minas Gerais, Brazil, is responsible for the routine monitoring of Occupationally Exposed Individuals (OEIs) to 18 F-FDG and other radiopharmaceuticals produced at CDTN. The monitoring system is usually calibrated using a physical head simulator, since 18 F is usually incorporated into the brain at the time of contamination. However, the geometry of the brain is not adequately represented by the latex pocket, which does not fill the entire volume of the volume skull. In this study, the characterization of the materials regarding the composition, density and attenuation coefficient of the materials used in the production of the new physical head simulator was carried out. An equivalent tissue material containing 97% water, 2.5% agar, 0.5% urea and 8 MBq of 18 F-FDG was produced, the interior of the skull was filled with the material. After solidification, experimental measurements were performed on the NaI(Tl) 3 x 3 s cintillation detector, the density of the simulant material was determined by the flotation method and the attenuation coefficient of the XCOM database software provided by NIST. It was concluded that the PVC skull has acceptable characteristics to simulate a human skull in 18 F-FDG internal dosimetry. The agar gel was shown to be a stable material capable of modeling different geometries and simulating the incorporation of 18 F-FDG into the brain. (author)

Methodology of ABNT ISO/IEC GUIA 25 implantation in the laboratories of radionuclides analysis in environmental samples of the Analysis Division/CNEN

International Nuclear Information System (INIS)

Oliveira, Josue Peter de

1997-07-01

The ISO/EEC Guide 25: 1993 Standard G eneral requirements for the competence of calibration and testing laboratories . Is published in Brazil by Brazilian Association for Technical Standards (ABNT) as ABNT ISO/DEC GUIA 25 and establishes general requirements a laboratory must demonstrate to meet, in order to be recognized as having technical competence (accreditation) to carry out specifics calibration or testing. Therefore, the accredited laboratory starts, respectively, taking part from the Brazilian Calibration Network (RBC) or from the Brazilian Testing Laboratories Network (RBLE) . The Environmental Radioanalysis Division (DIAMB) from Environmental Radiological Protection Department (DEPRA) from Institute of Radiation Protection and Dosimetry (IRD) from Brazilian National Nuclear Energy Commission (CNEN) is a laboratory responsible for analyzing radionuclides deriving for the samples from DEPRA's Surveillance Program, research and servings, due to an eventual radionuclide contamination in environment, foods and others raw materials for human consumption; including for importation and exportation products certification purposes. For all these reasons, DIAMB needs its formal recognition for carrying out radionuclides analysis in environmental samples. This work aims to provide a methodology in order to guide a laboratory which has the intention to implement a accreditation process. It also describes policies to meet the requirements related to the Standard, guidance needed to specification of some steps and also comments some points from the Standard in order to become easier all the accreditation process comprehension. (author)

Is Gerontology Ready for Accreditation?

Science.gov (United States)

Haley, William E.; Ferraro, Kenneth F.; Montgomery, Rhonda J. V.

2012-01-01

The authors review widely accepted criteria for program accreditation and compare gerontology with well-established accredited fields including clinical psychology and social work. At present gerontology lacks many necessary elements for credible professional accreditation, including defined scope of practice, applied curriculum, faculty with…

Calibrations of pocket dosemeters using a comparison method

International Nuclear Information System (INIS)

Somarriba V, I.

1996-01-01

This monograph is dedicated mainly to the calibration of pocket dosemeters. Various types of radiation sources used in hospitals and different radiation detectors with emphasis on ionization chambers are briefly presented. Calibration methods based on the use of a reference dosemeter were developed to calibrate all pocket dosemeters existing at the Radiation Physics and Metrology Laboratory. Some of these dosemeters were used in personnel dosimetry at hospitals. Moreover, a study was realized about factors that affect the measurements with pocket dosemeters in the long term, such as discharges due to cosmic radiation. A DBASE IV program was developed to store the information included in the hospital's registry

The accreditation programs and proficiency test in Taiwan for personnel dosimeter services (1991-1998)

International Nuclear Information System (INIS)

Lee, B.T.; Hwang, W.S.; Su, S.H.

2000-01-01

According to the ionizing radiation safety regulation approved by the ROC Atomic Energy Council (AEC), personnel dosimeter processors shall be accredited by the Chinese National Laboratory Accreditation (CNLA) program before offering dosimeter services and shall be accredited every two years (now has been rescheduled to be every three years since 1996). The aim of this program is to secure quality and technical capability of personnel dosimeters, and to provide systematic improvement for the internal calibration and testing laboratory applying for accreditation by means of assessment procedures. The criteria used to evaluate the capability at laboratories are ISO/IEC 25 (1990) and technical guide in different accreditation fields. The Institute of Nuclear Energy Research (INER) was entrusted by CNLA as the central laboratory to perform the proficiency test of personnel dosimeters for laboratory accreditation in December 1990. Such proficiency tests, based on ANSI N13.11 (1983), which is mainly separated to accident categories and protection categories which consists of eight parts of tests including single and mixture radiation of x-ray, gamma, beta and neutron, have been conducted four times, in 1991, 1993, 1995 and 1998. This paper deals with the test procedures and results of proficiency tests of personnel dosimeters from 1991 until 1998. The results of the four proficiency tests showed that, for accident categories, the pass rate is about 91%; for protection categories, the pass rate is about 98%. Meanwhile, the central laboratory will adopt a new version of HPS N13.11 (1993) to replace ANSI N13.11 (1983) as new criteria for the next proficiency test to be conducted in 2001. (author)

Accreditation in general practice in Denmark

DEFF Research Database (Denmark)

Andersen, Merethe K; Pedersen, Line B; Siersma, Volkert

2017-01-01

Background: Accreditation is used increasingly in health systems worldwide. However, there is a lack of evidence on the effects of accreditation, particularly in general practice. In 2016 a mandatory accreditation scheme was initiated in Denmark, and during a 3-year period all practices, as default...... general practitioners in Denmark. Practices allocated to accreditation in 2016 serve as the intervention group, and practices allocated to accreditation in 2018 serve as controls. The selected outcomes should meet the following criteria: (1) a high degree of clinical relevance; (2) the possibility...... practice and mortality. All outcomes relate to quality indicators included in the Danish Healthcare Quality Program, which is based on general principles for accreditation. Discussion: The consequences of accreditation and standard-setting processes are generally under-researched, particularly in general...

Calibration of RB reactor power; Kalibrisanje snage reaktora RB

Energy Technology Data Exchange (ETDEWEB)

Sotic, O; Markovic, H; Ninkovic, M; Strugar, P; Dimitrijevic, Z; Takac, S; Stefanovic, D; Kocic, A; Vranic, S [Boris Kidric Institute of Nuclear Sciences Vinca, Beograd (Yugoslavia)

1976-09-15

The first and only calibration of RB reactor power was done in 1962, and the obtained calibration ratio was used irrespective of the lattice pitch and core configuration. Since the RB reactor is being prepared for operation at higher power levels it was indispensable to reexamine the calibration ratio, estimate its dependence on the lattice pitch, critical level of heavy water and thickness of the side reflector. It was necessary to verify the reliability of control and dosimetry instruments, and establish neutron and gamma dose dependence on reactor power. Two series of experiments were done in June 1976. First series was devoted to tests of control and dosimetry instrumentation and measurements of radiation in the RB reactor building dependent on reactor power. Second series covered measurement of thermal and epithermal neuron fluxes in the reactor core and calculation of reactor power. Four different reactor cores were chosen for these experiments. Reactor pitches were 8, 8{radical}2, and 16 cm with 40, 52 and 82 fuel channels containing 2% enriched fuel. Obtained results and analysis of these results are presented in this document with conclusions related to reactor safe operation.

Standards of Quality: Accreditation Guidelines Redesigned

Science.gov (United States)

Forsythe, Hazel; Andrews, Frances; Stanley, M. Sue; Anderson, Carol L.

2011-01-01

To ensure optimal standards for AAFCS program accreditation, the Council for Accreditation (CFA) conducted a review and revision of the "2001 AAFCS Standards for Accreditation." The CFA took a three-pronged approach including (a) a review of academic accreditations that had relationships to the FCS disciplines, (b) concept, content, and process…

Hospital accreditation: staff experiences and perceptions.

Science.gov (United States)

Bogh, Søren Bie; Blom, Ane; Raben, Ditte Caroline; Braithwaite, Jeffrey; Thude, Bettina; Hollnagel, Erik; Plessen, Christian von

2018-06-11

Purpose The purpose of this paper is to understand how staff at various levels perceive and understand hospital accreditation generally and in relation to quality improvement (QI) specifically. Design/methodology/approach In a newly accredited Danish hospital, the authors conducted semi-structured interviews to capture broad ranging experiences. Medical doctors, nurses, a quality coordinator and a quality department employee participated. Interviews were audio recorded and subjected to framework analysis. Findings Staff reported that The Danish Healthcare Quality Programme affected management priorities: office time and working on documentation, which reduced time with patients and on improvement activities. Organisational structures were improved during preparation for accreditation. Staff perceived that the hospital was better prepared for new QI initiatives after accreditation; staff found disease specific requirements unnecessary. Other areas benefited from accreditation. Interviewees expected that organisational changes, owing to accreditation, would be sustained and that the QI focus would continue. Practical implications Accreditation is a critical and complete hospital review, including areas that often are neglected. Accreditation dominates hospital agendas during preparation and surveyor visits, potentially reducing patient care and other QI initiatives. Improvements are less likely to occur in areas that other QI initiatives addressed. Yet, accreditation creates organisational foundations for future QI initiatives. Originality/value The authors study contributes new insights into how hospital staff at different organisational levels perceive and understand accreditation.

Evaluating uncertainties in the cross-calibration of parallel ion chambers used in electron beam radiotherapy

International Nuclear Information System (INIS)

Anderson, Ernani; Travassos, Paulo; Ferreira, Max da Silva; Carvalho, Samira Marques de; Silva, Michele Maria da; Peixoto, Jose Guilherme Pereira; Salmon Junior, Helio Augusto

2015-01-01

This study aims to estimative the combined standard uncertainty for a detector parallel plate used for dosimetry of electron beams in linear accelerators for radiotherapy, which has been calibrated by the cross-calibration method. Keeping the combined standard uncertainty next of the uncertainty informed in the calibration certificate of the reference chamber, become possible establish the calibration factor of the detector. The combined standard uncertainty obtained in this study was 2.5 %. (author)

Calibration of reference KAP-meters at SSDL and cross calibration of clinical KAP-meters

International Nuclear Information System (INIS)

Hetland, Per O.; Friberg, Eva G.; Oevreboe, Kirsti M.; Bjerke, Hans H.

2009-01-01

In the summer of 2007 the secondary standard dosimetry laboratory (SSDL) in Norway established a calibration service for reference air-kerma product meter (KAP-meter). The air-kerma area product, PKA, is a dosimetric quantity that can be directly related to the patient dose and used for risk assessment associated with different x-ray examinations. The calibration of reference KAP-meters at the SSDL gives important information on parameters influencing the calibration factor for different types of KAP-meters. The use of reference KAP-meters calibrated at the SSDL is an easy and reliable way to calibrate or verify the PKA indicated by the x-ray equipment out in the clinics. Material and methods. Twelve KAP-meters were calibrated at the SSDL by use of the substitution method at five diagnostic radiation qualities (RQRs). Results. The calibration factors varied from 0.94 to 1.18. The energy response of the individual KAP-meters varied by a total of 20% between the different RQRs and the typical chamber transmission factors ranged from 0.78 to 0.91. Discussion. It is important to use a calibrated reference KAP-meter and a harmonised calibration method in the PKA calibration in hospitals. The obtained uncertainty in the PKA readings is comparable with other calibration methods if the information in the calibration certificate is correct used, corrections are made and proper positioning of the KAP-chamber is performed. This will ensure a reliable estimate of the patient dose and a proper optimisation of conventional x-ray examinations and interventional procedures

Comparing Hp(3) evaluated from the conversion coefficients from air kerma to personal dose equivalent for eye lens dosimetry calibrated on a new cylindrical PMMA phantom

Science.gov (United States)

Esor, J.; Sudchai, W.; Monthonwattana, S.; Pungkun, V.; Intang, A.

2017-06-01

Based on a new occupational dose limit recommended by ICRP (2011), the annual dose limit for the lens of the eye for workers should be reduced from 150 mSv/y to 20 mSv/y averaged over 5 consecutive years in which no single year exceeding 50 mSv. This new dose limit directly affects radiologists and cardiologists whose work involves high radiation exposure over 20 mSv/y. Eye lens dosimetry (Hp(3)) has become increasingly important and should be evaluated directly based on dosimeters that are worn closely to the eye. Normally, Hp(3) dose algorithm was carried out by the combination of Hp(0.07) and Hp(10) values while dosimeters were calibrated on slab PMMA phantom. Recently, there were three reports from European Union that have shown the conversion coefficients from air kerma to Hp(3). These conversion coefficients carried out by ORAMED, PTB and CEA Saclay projects were performed by using a new cylindrical head phantom. In this study, various delivered doses were calculated using those three conversion coefficients while nanoDot, small OSL dosimeters, were used for Hp(3) measurement. These calibrations were performed with a standard X-ray generator at Secondary Standard Dosimetry Laboratory (SSDL). Delivered doses (Hp(3)) using those three conversion coefficients were compared with Hp(3) from nanoDot measurements. The results showed that percentage differences between delivered doses evaluated from the conversion coefficient of each project and Hp(3) doses evaluated from the nanoDots were found to be not exceeding -11.48 %, -8.85 % and -8.85 % for ORAMED, PTB and CEA Saclay project, respectively.

42 CFR 8.13 - Revocation of accreditation and accreditation body approval.

Science.gov (United States)

2010-10-01

... GENERAL PROVISIONS CERTIFICATION OF OPIOID TREATMENT PROGRAMS Certification and Treatment Standards § 8.13... period of 1 year after the date of withdrawal of approval of the accreditation body, unless SAMHSA.... (2) Within 1 year from the date of withdrawal of approval of an accreditation body, or within any...

University Accreditation using Data Warehouse

Science.gov (United States)

Sinaga, A. S.; Girsang, A. S.

2017-01-01

The accreditation aims assuring the quality the quality of the institution education. The institution needs the comprehensive documents for giving the information accurately before reviewed by assessor. Therefore, academic documents should be stored effectively to ease fulfilling the requirement of accreditation. However, the data are generally derived from various sources, various types, not structured and dispersed. This paper proposes designing a data warehouse to integrate all various data to prepare a good academic document for accreditation in a university. The data warehouse is built using nine steps that was introduced by Kimball. This method is applied to produce a data warehouse based on the accreditation assessment focusing in academic part. The data warehouse shows that it can analyse the data to prepare the accreditation assessment documents.

CNEA's (Comision Nacional de Energia Atomica) experience in the preparation of a national system for laboratory accreditation

International Nuclear Information System (INIS)

Piacquadio, N.H.; Palacios, T.A.; Casa, V.A.; Koll, J.H.

1993-01-01

Within the regional markets, as it is the case of MERCOSUR , the laboratories which are suppliers of test and calibration results, are mutually recognized through the National Accreditation Systems. In Argentina there is a project to create a Center for the Accreditation of Test Laboratories. CNEA, which is involved in the execution of large projects and has adopted quality assurance criteria for a long time, requires for internal and external laboratories to be qualified. At the beginning of this year, a Committee for the Qualification of Laboratories was created in the Research and Development and Fuel Cycle Areas. Its objective was planning, management of documents, coordination, evaluation and quantification of laboratories, according to national IRAM and international ISO standards. This paper analyzes the organization of the system and the methods to evaluate and qualify laboratories as a process of growing up leading to the future National Accreditation System. (author). 3 figs

Experiences in the continuous improvement of quality assurance of the dosimetry services of SLDC-MD-ININ

International Nuclear Information System (INIS)

Tovar M, V. M.; Vergara M, F.; Perez M, V.; Anaya M, R.; Cejudo A, J.; Alvarez R, J. T.; Arenas O, A.; Cruz F, C.

2010-09-01

From 2003 the Secondary Laboratory of Dosimetric Calibration (SLDC) of Metrology Department of Ionizing Radiations (MD), has complemented the Quality Manual of National Institute of Nuclear Research (ININ) according to the standard ISO 9001: 2000. However, due to that the National Center of Metrology of Mexico delegates its functions in the dosimetry and activity area for the field of the ionizing radiations to the ININ: one of the requirements so that the ININ has been designated as -Declared Institute- before the International Office of Weights and Measurements, it is to demonstrate before the Inter-American System of Metrology that the quality system of the SLDC fulfills the standard ISO/IEC 17025: 2005, satisfied this requirement the Inter-American System of Metrology in their meeting of evaluation of quality systems, Ottawa (2007) grants a certification document to the SLDC that guarantees their capacities of calibration measurements for dosimetry services. Concretely, inside the standard activities ISO 9000 with respect to the point 8 on measurement, analysis and improvement the Management of Quality Assurance of ININ carries out at year two interns auditing and every month is given continuation to the non conformities detected in the procedures that support the services of the SLDC for dosimetry with purposes of radiological protection and clinical dosimetry. (Author)

Quality assurance of the treatments performed with a linear accelerator by means of in vivo dosimetry

International Nuclear Information System (INIS)

Jornet, N.; Ribas, M.; Eudaldo, T.; Carrasco, P.

2001-01-01

In vivo dosimetry by means of diode detectors has been used routinely in our hospital since 1996 to guarantee the dose administrated to patients undergoing a radiotherapy treatment. The aim of this work is to present how in vivo dosimetry was implemented in our centre and which kind of errors have been discovered and corrected. Before the implementation it has to be clear which kind of errors want to be traced, the tolerance and action level, who will perform the measurements and who will evaluate them. Once all these things are clear, the first thing to do is to choose the more appropriate type of diodes and to calibrate them. The lower the tolerance level, the more accurate the calibration has to be. At this point the training and motivation of people who will be involved is very important to succeed in implementing routine use of in vivo dosimetry. Choosing one treatment unit and one easy and frequent treatment technique is a good way of starting implementation. We started with prostate treatments. In vivo entrance and exit doses were measured and dose to the ICRU point was calculated. Nowadays in vivo dosimetry is performed in the second session of all treatments (X-rays and electrons). (author)

Secondary calibration laboratory for dosimetry in levels of therapy at the University of Santiago; Laboratorio secundario de calibracion para dosimetria en niveles de terapia en la Universidad de Santiago

Energy Technology Data Exchange (ETDEWEB)

Gomez Rodriguez, F.; Gonzalez Castano, D. M.; Pazos Alvarez, A.

2011-07-01

A basic inherent benefits provided by the existence of a traceability chain radiation in any application, add the legal requirement for hospitals as pointed to by the RO. 1566/1998, which sets quality standards in radiotherapy. The decree attributed to hospital specialists radio physics in article 10 the responsibility for determining the acceptance and initial reference state of radiation generating equipment for therapeutic purposes, and the establishment and implementation of quality control programs associated and technical and physical aspects of radiation dosimetry. Different international organizations such as ICRU and IAEA recommendations on maintaining the accuracy of the dose delivered to patients in general, should be placed at least 5% considering the whole chain irradiation. In order to achieve this purpose it is necessary to establish programs of quality control and calibration dosimetric regular basis. The protocol of the IAEA TRS398 recommended dose calibration in water because it is a quantity of interest closest to clinical use and allows a relative uncertainty in the calibration environment reduced to 1%.. (Author)

TU-D-201-03: Results of a Survey On the Implementation of the TG-51 Protocol and Associated Addendum On Reference Dosimetry of External Beams

Energy Technology Data Exchange (ETDEWEB)

Kim, G [University of California, San Diego, La Jolla, CA (United States); Muir, B [National Research Council, Ottawa, AB (Canada); Culberson, W [University of Wisconsin Madison, Madison, WI (United States); Davis, S [McGill University Health Center, Montreal, QC (Canada); Huang, Y [Henry Ford Health System, West Bloomfield, MI (United States); Lee, S [University of Maryland School of Medicine, Columbia, MD (United States); Lowenstein, J [UT MD Anderson Cancer Center, Houston, TX (United States); Sarfehnia, A [Sunnybrook Health Science Center, Toronto, ON (Canada); Tolani, N [Michael E. DeBakey VA Medical Center, Sugarland (United States); Siebers, J [University of Virginia Health System, Charlottesville, VA (United States)

2016-06-15

Purpose: The working group on the review and extension of the TG-51 protocol (WGTG51) collected data from American Association of Physicists in Medicine (AAPM) members with respect to their current TG-51 and associated addendum usage in the interest of considering future protocol addenda and guidance on reference dosimetry best practices. This study reports an overview of this survey on dosimetry of external beams. Methods: Fourteen survey questions were developed by WGTG51 and released in November 2015. The questions collected information on reference dosimetry, beam quality specification, and ancillary calibration equipment. Results: Of the 190 submissions completed worldwide (U.S. 70%), 83% were AAPM members. Of the respondents, 33.5% implemented the TG-51 addendum, with the maximum calibration difference for any photon beam, with respect to the original TG-51 protocol, being <1% for 97.4% of responses. One major finding is that 81.8% of respondents used the same cylindrical ionization chamber for photon and electron dosimetry, implying that many clinics are foregoing the use of parallel-plate chambers. Other evidence suggests equivalent dosimetric results can be obtained with both cylindrical and parallel-plate chambers in electron beams. This, combined with users comfort with cylindrical chambers for electrons will likely impact recommendations put forward in an upcoming electron beam addendum to the TG-51 protocol. Data collected on ancillary equipment showed 58.2% (45.0%) of the thermometers (barometers) in use for beam calibration had NIST traceable calibration certificates, but 48.4% (42.7%) were never recalibrated. Conclusion: This survey provides a snapshot of TG-51 external beam reference dosimetry practice in radiotherapy centers. Findings demonstrate the rapid take-up of the TG-51 photon beam addendum and raise issues for the WGTG51 to focus on going forward, including guidelines on ancillary equipment and the choice of chamber for electron beam

Evaluation of the energy dependence of ionization chambers pencil type calibrated beam tomography standards

International Nuclear Information System (INIS)

Fontes, Ladyjane Pereira; Potiens, Maria da Penha A.

2015-01-01

The Instrument Calibration Laboratory of IPEN (LCI - IPEN) performs calibrations of pencil-type ionization chambers (IC) used in measures of dosimetric survey on clinical systems of Computed Tomography (CT). Many users make mistakes when using a calibrated ionization chamber in their CT dosimetry systems. In this work a methodology for determination of factors of correction for quality (Kq) through the calibration curve that is specific for each ionization chamber was established. Furthermore, it was possible to demonstrate the energy dependence on an pencil-type Ionization Chamber(IC) calibrated at the LCI - IPEN. (author)

Calibration procedures for mammography dosemeters in Poland

International Nuclear Information System (INIS)

Gwiazdowska, B.; Ulkowski, P.; Tolwinski, J.; Bulski, W.

2002-01-01

Breast cancer is the most frequent tumour in women and the effectiveness of the treatment depends dramatically on the early detection of the disease. That is the reason why in Poland the mammography control examinations are strongly supported by the Centre of Oncology. In Poland there are over 400 mammography units which account for about 300,000 examinations per year. An investigation performed by the Medical Physics Department of the Centre of Oncology in Warsaw at about 100 mammography facilities proved that in most cases the doses absorbed by the patients could be reduced without decrease of image quality. This is one of the reasons why the Polish Secondary Standard Dosimetry Laboratory (SSDL) dealing mainly with calibration of radiotherapy dosemeters is extending its activities and therefore new facilities and equipment adapted for calibration of mammographic dosemeters have been installed. The mammography dosimetry calibration equipment is permanently installed in the same laboratory room where the radiotherapy dosemeters are calibrated. A base of a mammography unit no longer in clinical use, together with its movable system has been adapted to handle ionization chamber holders. An X-ray tube with a 50 kV high frequency generator was also installed. The tube, a Varian type OEG-50-2, (designed for laboratory applications) with molybdenum anode of an anode angle 23,7 deg. and with a large focus, effective size approximately 5 mm 2 , has an inherent filtration of 0,25 mm beryllium. It is installed in a housing with 2mm lead shielding; a cone shaped beam is formed by a system of three collimators

Test of an albedo neutron dosimetry system: TLD calibration and readout procedure, neutron calibration, dosimetry properties, routine application

International Nuclear Information System (INIS)

Piesch, E.; Burgkhardt, B.

1988-03-01

The two-component albedo dosemeter in use consists of an universal boron-loaded plastic encapsulation, the beta and albedo neutron windows of which are adopted to the corresponding TLD system of the manufacturers Alnor, Harshaw, Panasonic and Vinten. Beside the TLD detectors the capsule may contain also track etch detectors. Within a BMU project the system was investigated by four governmental measurement services in the FRG with respect to its qualification for personnel monitoring with emphasis in the readout and calibration procedures for the TLD system, the evaluation technique for the estimation of the photon and neutron dose equivalent in routine monitoring and the calibration of the personnel dosemeter in stray neutron fields. The test has shown the readiness of the system to act in the application areas of nuclear power reactors and linacs behind heavy shieldings, in the fuel element cycle, use of fissile materials, criticality, use of radionuclide sources, high energy particle accelerators. The uncertainty due to energy dependence was found to be within a factor of 2 for a single application area. In the case of irradiations from the front half space the dose equivalent H'(10) is indicated sufficiently independent of the direction of the radiation incidence. After completion of the test the albedo dosemeter became the official neutron personnel dosemeter in the FRG. It allows the separate estimation of the dose equivalent of hard beta radiation, photon radiation and neutrons. (orig./HP) [de

Development of an international code of practice for dosimetry in X-ray diagnostic radiology

International Nuclear Information System (INIS)

Pernicka, F.; Carlsson, G.A.; Dance, D.R.; DeWerd, L.A.; Kramer, H.-M.; Ng, K.-H.

2001-01-01

Medical x-ray examinations contribute greatly to the population dose from man-made radiation sources. There is a need to control this dose and therefore to optimise the design and use of x-ray imaging systems. A key stage in this process is the standardisation of the procedures for dose measurement in the clinic. The Dosimetry and Medical Radiation Physics Section of the IAEA has a number of activities to further advance the standards for x-ray diagnostics. One of these activities is the coordination of a working group to develop a code of practice, which will facilitate the IAEA calibration activities, TLD intercomparisons and audits, educational activities, and technical assistance to Member States. The code of practice will aid in the standardisation of various dosimetric techniques in x-ray diagnostic radiology. The CoP working group has had an initial meeting to review the current status of dosimetry for conventional radiology, fluoroscopy, mammography, computed tomography and dental radiology. The CoP will include the establishment of standards and calibrations at the SSDLs, phantom and patient measurements and procedures for dosimetry in the clinic. (author)

Dosimetry at the Los Alamos Critical Experiments Facility: Past, present, and future

International Nuclear Information System (INIS)

Malenfant, R.E.

1993-10-01

Although the primary reason for the existence of the Los Alamos Critical Experiments Facility is to provide basic data on the physics of systems of fissile material, the physical arrangements and ability to provide sources of radiation have led to applications for all types of radiation dosimetry. In the broad definition of radiation phenomena, the facility has provided sources to evaluate biological effects, radiation shielding and transport, and measurements of basic parameters such as the evaluation of delayed neutron parameters. Within the last 15 years, many of the radiation measurements have been directed to calibration and intercomparison of dosimetry related to nuclear criticality safety. Future plans include (1) the new applications of Godiva IV, a bare-metal pulse assembly, for dosimetry (including an evaluation of neutron and gamma-ray room return); (2) a proposal to relocate the Health Physics Research Reactor from the Oak Ridge National Laboratory to Los Alamos, which will provide the opportunity to continue the application of a primary benchmark source to radiation dosimetry; and (3) a proposal to employ SHEBA, a low-enrichment solution assembly, for accident dosimetry and evaluation

IADC's well control accreditation program

International Nuclear Information System (INIS)

Kropla, S.M.

1997-01-01

WellCAP is a well control accreditation program devised and implemented by the International Association of Drilling Contractors (IADC). It is a worldwide comprehensive system that defines a well control training curriculum, establishes minimum standards and recommends guidelines for course structure. The program began in mid-1993 and is viewed as a means for training institutions to demonstrate industry recognition to customers, contractors and local governments. Schools can apply to have their courses accredited. The accreditation system is administered by a review panel. The application process requires that the school perform a detailed review of its curriculum and operations and bring them in line with the WellCAP curriculum and accreditation criteria. Currently, more than 75 schools around the world have requested application materials for WellCAP. To date fifteen schools have been fully accredited

EURADOS intercomparison 2006 to harmonise European early warning dosimetry systems

International Nuclear Information System (INIS)

Dombrowski, H.; Neumaier, S.; Thompson, I. M. G.; Wissmann, F.

2009-01-01

In 2006, the European Radiation Dosimetry (EURADOS) Working Group on Environmental Radiation Monitoring (WG3) organised a third European intercomparison of dosimetry systems operated in national early warning networks. Similar to the intercomparisons in 1999 and 2002, the main aim of this exercise was to support the process of harmonisation of area monitoring in Europe by providing the network operators with basic information on the calibration and performance of their dosimetry systems. In order to characterise these systems, their following basic parameters were investigated: the response to terrestrial and cosmic radiation, the detectors' inherent background, the response at low dose rates, the energy dependence of the response as well as the sensitivity of the detector systems to small changes of the dose rate in a natural environmental radiation field. In the 2006 EURADOS intercomparison, scientists from seven countries participated to study the characteristics of 11 detector systems. All results are presented in terms of the operational quantity ambient dose equivalent, H * (10). The advent of this quantity has caused the development of new detector systems for area monitoring. Some of these new systems participated in a EURADOS intercomparison for the first time. The results are consistently presented together with uncertainties so that statistical effects can be distinguished from real detector features, which improves the interpretation of the results. By using the results of this intercomparison, some detectors were re-calibrated. The achievable improvements concerning harmonisation in dose-rate measurements in the natural environment are discussed. (authors)

Investigation of the applicability of a special parallel-plate ionization chamber for x-ray beam dosimetry

International Nuclear Information System (INIS)

Perini, Ana P.; Neves, Lucio P.; Caldas, Linda V.E.

2014-01-01

Diagnostic x-rays are the greatest source of exposition to ionizing radiation of the population worldwide. In order to obtain accurate and lower-cost dosimeters for quality control assurance of medical x-ray facilities, a special ionization chamber was designed at the Calibration Laboratory of the IPEN, for dosimetry in diagnostic radiology beams. For the chamber characterization some tests were undertaken. Monte Carlo simulations were proposed to evaluate the distribution of the deposited energy in the sensitive volume of the ionization chamber and the collecting electrode effect on the chamber response. According to the obtained results, this special ionization chamber presents potential use for dosimetry of conventional diagnostic radiology beams. - Highlights: • An ionization chamber with a novel design was characterized for x-ray beam dosimetry. • This ionization chamber was evaluated in diagnostic radiology qualities. • The characterization tests results were within the recommended limits. • Monte Carlo simulations were employed to evaluate the design of the dosimeter. • The developed prototype is a good alternative for calibration laboratories and clinics

Worldwide QA networks for radiotherapy dosimetry

International Nuclear Information System (INIS)

Izewska, J.; Svensson, H.; Ibbott, G.

2002-01-01

A number of national or international organizations have developed various types and levels of external audits for radiotherapy dosimetry. There are three major programmes who make available external audits, based on mailed TLD (thermoluminescent dosimetry), to local radiotherapy centres on a regular basis. These are the IAEA/WHO TLD postal dose audit service operating worldwide, the European Society for Therapeutic Radiology and Oncology (ESTRO) system, EQUAL, in European Union (EU) and the Radiological Physics Center (RPC) in North America. The IAEA, in collaboration with WHO, was the first organization to initiate TLD audits on an international scale in 1969, using mailed system, and has a well-established programme for providing dose verification in reference conditions. Over 32 years, the IAEA/WHO TLD audit service has checked the calibration of more than 4300 radiotherapy beams in about 1200 hospitals world-wide. Only 74% of those hospitals who receive TLDs for the first time have results with deviation between measured and stated dose within acceptance limits of ±5%, while approximately 88% of the users that have benefited from a previous TLD audit are successful. EQUAL, an audit programme set up in 1998 by ESTRO, involves the verification of output for high energy photon and electron beams, and the audit of beam parameters in non-reference conditions. More than 300 beams are checked each year, mainly in the countries of EU, covering approximately 500 hospitals. The results show that although 98% of the beam calibrations are within the tolerance level of ±5%, a second check was required in 10% of the participating centres, because a deviation larger than ±5% was observed in at least one of the beam parameters in non-reference conditions. EQUAL has been linked to another European network (EC network) which tested the audit methodology prior to its application. The RPC has been funded continuously since 1968 to monitor radiation therapy dose delivery at

Tracking Success: Outputs Versus Outcomes-A Comparison of Accredited and Non-Accredited Public Health Agencies' Community Health Improvement Plan objectives.

Science.gov (United States)

Perrault, Evan K; Inderstrodt-Stephens, Jill; Hintz, Elizabeth A

2018-06-01

With funding for public health initiatives declining, creating measurable objectives that are focused on tracking and changing population outcomes (i.e., knowledge, attitudes, or behaviors), instead of those that are focused on health agencies' own outputs (e.g., promoting services, developing communication messages) have seen a renewed focus. This study analyzed 4094 objectives from the Community Health Improvement Plans (CHIPs) of 280 local PHAB-accredited and non-accredited public health agencies across the United States. Results revealed that accredited agencies were no more successful at creating outcomes-focused objectives (35% of those coded) compared to non-accredited agencies (33% of those coded; Z = 1.35, p = .18). The majority of objectives were focused on outputs (accredited: 61.2%; non-accredited: 63.3%; Z = 0.72, p = .47). Outcomes-focused objectives primarily sought to change behaviors (accredited: 85.43%; non-accredited: 80.6%), followed by changes in knowledge (accredited: 9.75%; non-accredited: 10.8%) and attitudes (accredited: 1.6%; non-accredited: 5.1%). Non-accredited agencies had more double-barreled objectives (49.9%) compared to accredited agencies (32%; Z = 11.43, p < .001). The authors recommend that accreditation procedures place a renewed focus on ensuring that public health agencies strive to achieve outcomes. It is also advocated that public health agencies work with interdisciplinary teams of Health Communicators who can help them develop procedures to effectively and efficiently measure outcomes of knowledge and attitudes that are influential drivers of behavioral changes.

Chemical dosimetry principles in high dose dosimetry

International Nuclear Information System (INIS)

Mhatre, Sachin G.V.

2016-01-01

In radiation processing, activities of principal concern are process validation and process control. The objective of such formalized procedures is to establish documentary evidence that the irradiation process has achieved the desired results. The key element of such activities is inevitably a well characterized reliable dosimetry system that is traceable to recognized national and international dosimetry standards. Only such dosimetry systems can help establish the required documentary evidence. In addition, industrial radiation processing such as irradiation of foodstuffs and sterilization of health careproducts are both highly regulated, in particular with regard to dose. Besides, dosimetry is necessary for scaling up processes from the research level to the industrial level. Thus, accurate dosimetry is indispensable

Traceable calibration of hospital 192Ir HDR sources

International Nuclear Information System (INIS)

Govinda Rajan, K.N.; Bhatt, B.C.; Pendse, A.M.; Kannan, V.

2002-01-01

Presently, no primary standard exists for the standardization of remote afterloading 192 Ir HDR sources. These sources are, therefore, being standardized by a few Secondary Standard Dosimetry Laboratories (SSDLs), in terms of Air Kerma Strength (AKS) or Reference Air Kerma Rate (RAKR) using a 0.6 cc Farmer type chamber, set up as an Interim Standard. These SSDLs offer calibration to well type of ionization chambers that are normally used by the hospitals for calibrating the 192 lr HDR source. Presently, in many countries, including India, well chambers are not commercially available. Nor do these countries offer any calibration service for 192 lr HDR source. With the result users make use of well chambers imported from different countries with their calibration traceable to the country of origin. Since no intercomparisons between these countries have been reported, the measurement consistency between hospitals becomes questionable. The problem is compounded by the fact that these chambers are used for several years without re-calibration since no calibration service is locally available. For instance, in India, the chambers have been in use in hospitals, since 1994, without a second calibration. Not all hospitals use the well chamber for the calibration of the 192 lr HDR source. Many hospitals make use of 0.6 cc chambers, in air, at short source to chamber distances, for measuring the AKS of the source. The latter method is prone to much larger inaccuracy due to the use of very short source to chamber distances without proper calibration jigs, use of 60 Co calibration factor for 192 Ir HDR source calibrations, neglecting correction factors for room scatter, fluence non-uniformity, use of arbitrary buildup factors for the buildup cap of the chamber etc. A comparison of the procedures used at hospitals revealed that various arbitrary methods are in use at hospitals. An indigenously developed well chamber was calibrated against a Reference Standard traceable to the

ALGORITHM VERIFICATION FOR A TLD PERSONAL DOSIMETRY SYSTEM

International Nuclear Information System (INIS)

SHAHEIN, A.; SOLIMAN, H.A.; MAGHRABY, A.

2008-01-01

Dose algorithms are used in thermoluminescence personnel dosimetry for the interpretation of the dosimeter response in terms of equivalent dose. In the present study, an automated Harshaw 6600 reader was vigorously tested prior to the use for dose calculation algorithm according to the standard established by the US Department of Energy Laboratory Accreditation Program (DOELAP). Also, manual Harshaw 4500 reader was used along with the ICRU slab phantom and the RANDO phantom in experimentally determining the photon personal doses in terms of deep dose; Hp(10), shallow dose; Hp(0.07), and eye lens dose; Hp(3). Also, a Monte Carlo simulation program (VMC-dc) free code was used to simulate RANDO phantom irradiation process. The accuracy of the automated system lies well within DOELAP tolerance limits in all test categories

Calibrating page sized Gafchromic EBT3 films

International Nuclear Information System (INIS)

Crijns, W.; Maes, F.; Heide, U. A. van der; Van den Heuvel, F.

2013-01-01

Purpose: The purpose is the development of a novel calibration method for dosimetry with Gafchromic EBT3 films. The method should be applicable for pretreatment verification of volumetric modulated arc, and intensity modulated radiotherapy. Because the exposed area on film can be large for such treatments, lateral scan errors must be taken into account. The correction for the lateral scan effect is obtained from the calibration data itself. Methods: In this work, the film measurements were modeled using their relative scan values (Transmittance, T). Inside the transmittance domain a linear combination and a parabolic lateral scan correction described the observed transmittance values. The linear combination model, combined a monomer transmittance state (T 0 ) and a polymer transmittance state (T ∞ ) of the film. The dose domain was associated with the observed effects in the transmittance domain through a rational calibration function. On the calibration film only simple static fields were applied and page sized films were used for calibration and measurements (treatment verification). Four different calibration setups were considered and compared with respect to dose estimation accuracy. The first (I) used a calibration table from 32 regions of interest (ROIs) spread on 4 calibration films, the second (II) used 16 ROIs spread on 2 calibration films, the third (III), and fourth (IV) used 8 ROIs spread on a single calibration film. The calibration tables of the setups I, II, and IV contained eight dose levels delivered to different positions on the films, while for setup III only four dose levels were applied. Validation was performed by irradiating film strips with known doses at two different time points over the course of a week. Accuracy of the dose response and the lateral effect correction was estimated using the dose difference and the root mean squared error (RMSE), respectively. Results: A calibration based on two films was the optimal balance between

Answer to request on the ININ internal dosimetry

International Nuclear Information System (INIS)

Alfaro L, M.M.

1999-05-01

In this report it is presented the reply to CNSNS asking for information about the methodology for the evaluation of the occupational dose due to internal contamination. The characteristics of the installation, type and dimensions of the shield room, construction materials, type of detecting, calibration geometries, type of used phantom, intervals of energy of the calibration, type of routine measurements, detection limit for Cs-137 and Co-60, code to carry out the analysis of the spectra, evaluation of the measurement data, whole body system type armchair with anthropomorphic phantom, whole body system of vertical scanning, distribution and location diagram of the internal dosimetry laboratory there are among the treated aspects. (Author

Characterization of the materials used in the construction of a physical phantom for calibration of {sup 18}F-FDG internal dosimetry system

Energy Technology Data Exchange (ETDEWEB)

Vital, Katia D.; Mendes, Bruno M.; Fonseca, Telma C.F.; Silva, Teógenes A. da, E-mail: katiadvitall@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte - MG (Brazil)

2017-07-01

The Internal Dosimetry Laboratory (LDI) of the Nuclear Technology Development Center (CDTN) in Minas Gerais, Brazil, is responsible for the routine monitoring of Occupationally Exposed Individuals (OEIs) to {sup 18}F-FDG and other radiopharmaceuticals produced at CDTN. The monitoring system is usually calibrated using a physical head simulator, since {sup 18}F is usually incorporated into the brain at the time of contamination. However, the geometry of the brain is not adequately represented by the latex pocket, which does not fill the entire volume of the volume skull. In this study, the characterization of the materials regarding the composition, density and attenuation coefficient of the materials used in the production of the new physical head simulator was carried out. An equivalent tissue material containing 97% water, 2.5% agar, 0.5% urea and 8 MBq of {sup 18}F-FDG was produced, the interior of the skull was filled with the material. After solidification, experimental measurements were performed on the NaI(Tl) 3 {sup x}3{sup s}cintillation detector, the density of the simulant material was determined by the flotation method and the attenuation coefficient of the XCOM database software provided by NIST. It was concluded that the PVC skull has acceptable characteristics to simulate a human skull in {sup 18}F-FDG internal dosimetry. The agar gel was shown to be a stable material capable of modeling different geometries and simulating the incorporation of {sup 18}F-FDG into the brain. (author)

Alanine-EPR as a transfer standard dosimetry system for low energy X radiation

International Nuclear Information System (INIS)

Khoury, H.J.; Silva, E.J. da; Mehta, K.; Barros, V.S. de; Asfora, V.K.; Guzzo, P.L.; Parker, A.G.

2015-01-01

The purpose of this paper is to evaluate the use of alanine-EPR as a transfer standard dosimetry system for low energy X radiation, such as that in RS-2400, which operates in the range from 25 to 150 kV and 2 to 45 mA. Two types of alanine dosimeters were investigated. One is a commercial alanine pellets from Aérial-Centre de Ressources Technologiques, France and one was prepared in our laboratory (LMRI-DEN/UFPE). The EPR spectra of the irradiated dosimeters were recorded in the Nuclear Energy Department of UFPE, using a Bruker EMX10 EPR spectrometer operating in the X-band. The alanine-EPR dosimetry system was calibrated in the range of 20–220 Gy in this X-ray field, against an ionization chamber calibrated at the relevant X-ray energy with traceability to PTB. The results showed that both alanine dosimeters presented a linear dose response the same sensitivity, when the EPR signal was normalized to alanine mass. The total uncertainty in the measured dose was estimated to be about 3%. The results indicate that it is possible to use the alanine-EPR dosimetry system for validation of a low-energy X ray irradiator, such as RS-2400.

Accreditation Outcome Scores: Teacher Attitudes toward the Accreditation Process and Professional Development

Science.gov (United States)

Ulmer, Phillip Gregory

2015-01-01

Accreditation is an essential component in the history of education in the United States and is a central catalyst for quality education, continuous improvement, and positive growth in student achievement. Although previous researchers identified teachers as an essential component in meeting accreditation outcomes, additional information was…

Comparison of infusion pumps calibration methods

Science.gov (United States)

Batista, Elsa; Godinho, Isabel; do Céu Ferreira, Maria; Furtado, Andreia; Lucas, Peter; Silva, Claudia

2017-12-01

Nowadays, several types of infusion pump are commonly used for drug delivery, such as syringe pumps and peristaltic pumps. These instruments present different measuring features and capacities according to their use and therapeutic application. In order to ensure the metrological traceability of these flow and volume measuring equipment, it is necessary to use suitable calibration methods and standards. Two different calibration methods can be used to determine the flow error of infusion pumps. One is the gravimetric method, considered as a primary method, commonly used by National Metrology Institutes. The other calibration method, a secondary method, relies on an infusion device analyser (IDA) and is typically used by hospital maintenance offices. The suitability of the IDA calibration method was assessed by testing several infusion instruments at different flow rates using the gravimetric method. In addition, a measurement comparison between Portuguese Accredited Laboratories and hospital maintenance offices was performed under the coordination of the Portuguese Institute for Quality, the National Metrology Institute. The obtained results were directly related to the used calibration method and are presented in this paper. This work has been developed in the framework of the EURAMET projects EMRP MeDD and EMPIR 15SIP03.

100 years of solid state dosimetry and radiation protection dosimetry

International Nuclear Information System (INIS)

Bartlett, David T.

2008-01-01

The use of solid state detectors in radiation dosimetry has passed its 100th anniversary. The major applications of these detectors in radiation dosimetry have been in personal dosimetry, retrospective dosimetry, dating, medical dosimetry, the characterization of radiation fields, and also in microdosimetry and radiobiology research. In this introductory paper for the 15th International Conference, I shall speak of the history of solid state dosimetry and of the radiation measurement quantities that developed at the same time, mention some landmark developments in detectors and applications, speak a bit more about dosimetry and measurement quantities, and briefly look at the past and future

Commission for the Accreditation of Birth Centers

Science.gov (United States)

... Learning Login: Commissioners Birth Centers CABC Learning Place Home Accredited Birth Centers Find CABC Accredited Birth Centers What does ... In the Pursuit of Excellence You are here: Home In the ... for the Accreditation of Birth Centers (CABC) provides support, education, and accreditation to ...

Dosimetry during mango irradiation using Gafchromic HD-810 film

International Nuclear Information System (INIS)

Sharma, S. D.; Chilkulwar, R. H.; Kumar, R.

2009-01-01

The dosimetric characteristics of Gafchromic HD-810 film were evaluated for its possible use as a high-dose dosemeter for routine dosimetry during mango irradiation. The film dosemeter sample of size 2 x 2 cm 2 was used throughout the course of this work. The irradiation of the film dosemeter for characterisation and calibration purposes was carried out in a gamma irradiator. The dose-response of the Gafchromic HD-810 film dosemeter at 550 nm was found to be linear in the dose range 50-1000 Gy, which indicates the feasibility of using this film for dosimetry up to 1000 Gy. The mean inter-dosemeter variation was within 2%, which gives better dose-response consistency of the HD-810 film. The radiation absorbed dose measured by the Gafchromic HD-810 film dosemeter during mango irradiation was compared with that measured by a standard Ceric-cerous dosemeter. This study establishes the Gafchromic HD-810 film as a convenient and technically suitable dosemeter for high-dose dosimetry up to 1.0 kGy during mango irradiation. (authors)

Personnel dosimetry methods introduced in the Czechoslovak national laboratories

International Nuclear Information System (INIS)

Trousil, J.; Singer, J.; Kokta, L.; Prouza, Z.

1979-01-01

Personnel dosimetry methods are described that were developed in the Institute for Research, Production and Application of Radioisotopes and that have been or will be introduced in the national personnel dosimetry service. In Czechoslovakia, workers exposed to a radiation risk are divided into two groups, according to the level of the risk. The criterion is the possibility of exceeding one tenth of the MPD. For the higher risk group, a complex dose meter is usually used for dosimetry of photon and beta radiation; it contains a film dose meter and a radiothermoluminescent (RTL) glass dose meter. The RTL glass dose meter also serves as an accident dose meter. For neutron dosimetry, a dose meter comprising a solid-state track detector in combination with fissionable foils has been introduced. For accident dosimetry, a silicon diode of Czechoslovak production is used. For the lower risk group, only the introduction of an RTL dose meter is foreseen. There will be a three month control period; for neutron dosimetry, the track detector in combination with fissionable foils is retained. For measurements of hand doses, a themoluminescent ring dose meter has been introduced. The dose meters are described, giving information on the types of detectors employed, measurement techniques and descriptions of the basic characteristics of the instruments, their basic dosimetric parameters and the dose and energy ranges which can be measured. The results of international comparisons are presented; these have served to confirm the measurement precision. In conclusion, some questions of dose-meter calibration are summarized, and the problems of dose measurement in mixed fields of neutrons and gamma rays are discussed. (author)

22 CFR 96.99 - Converting an application for temporary accreditation to an application for full accreditation.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Converting an application for temporary accreditation to an application for full accreditation. 96.99 Section 96.99 Foreign Relations DEPARTMENT OF... INTERCOUNTRY ADOPTION ACT OF 2000 (IAA) Procedures and Standards Relating to Temporary Accreditation § 96.99...

Dosimetry intercomparisons between fast neutron radiotherapy facilities

International Nuclear Information System (INIS)

Almond, P.R.; Smith, A.R.; Smathers, J.B.; Otte, V.A.

1975-01-01

Neutron dosimetry intercomparisons have been made between M.D. Anderson Hospital and Tumor Institute, Naval Research Laboratory, University of Washington Hospital, and Hammersmith Hospital. The parameters that are measured during these visits are: tissue kerma in air, tissue dose at depth of dose maximum, depth dose, beam profiles, neutron/gamma ratios and photon calibrations of ionization chambers. A preliminary report of these intercomparisons will be given including a comparison of the calculation and statement of tumor doses for each institution

Neutron dosimetry of the Little Boy device

International Nuclear Information System (INIS)

Pederson, R.A.; Plassmann, E.A.

1984-01-01

Neutron dose rates at several angular locations and at distances out to 0.5 mile have been measured during critical operation of the Little Boy replica. We used modified remmetes and thermoluminescent dosimetry techniques for the measurements. The present status of our analysis is presented including estimates of the neutron-dose-relaxation length in air and the variation of the neutron-to-gamma-ray dose ratio with distance from the replica. These results are preliminary and are subject to detector calibration measurements

7 CFR 205.506 - Granting accreditation.

Science.gov (United States)

2010-01-01

..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) ORGANIC FOODS PRODUCTION ACT PROVISIONS NATIONAL ORGANIC PROGRAM Accreditation of Certifying Agents § 205.506 Granting accreditation. (a... accreditation as provided in § 205.510(c), the certifying agent voluntarily ceases its certification activities...

Quality control for dose calibrators

International Nuclear Information System (INIS)

Mendes, L.C.G.

1984-01-01

Nuclear medicine laboratories are required to assay samples of radioactivity to be administered to patients. Almost universally, these assays are accomplished by use of a well ionization chamber isotope calibrator. The Instituto de Radioprotecao e Dosimetria (Institute for Radiological Protection and Dosimetry) of the Comissao Nacional de Energia Nuclear (National Commission for Nuclear Energy) is carrying out a National Quality Control Programme in Nuclear Medicine, supported by the International Atomic Energy Agency. The assessment of the current needs and practices of quality control in the entire country of Brazil includes Dose Calibrators and Scintillation Cameras, but this manual is restricted to the former. Quality Control Procedures for these Instruments are described in this document together with specific recommendations and assessment of its accuracy. (author)

Proposed Accreditation Standards for Degree-Granting Correspondence Programs Offered by Accredited Institutions.

Science.gov (United States)

McGraw-Hill Continuing Education Center, Washington, DC.

A study on proposed accreditation standards grew out of a need to (1) stimulate the growth of quality correspondence degree programs; and (2) provide a policy for accreditation of correspondence degree programs so that graduates would be encouraged to pursue advanced degree programs offered elsewhere by educational institutions. The study focused…

Biological dosimetry study in differentiated thyroid carcinoma patients treated with 131Iodine

International Nuclear Information System (INIS)

Vallerga, Maria Belen

2008-11-01

Biological Dosimetry allows individual dose assessments based on the effect produced by ionizing radiation on a given biological parameter. The current biological endpoint being scored is chromosomal aberrations, relying on a lymphocytes culture from the patient's blood. The measured yield of chromosome aberrations is referred to a calibration curve obtaining the whole body dose. Different scenarios of overexposure can be taken into account by modifying the calculations leading to the dose estimate. Differentiated Thyroid Carcinoma patients undergo thyroidectomy followed by internal radiotherapy with 131 I. The treatment's success entails the delivery of a lethal dose to the tumour within the maximum tolerable dose to a critical organ (blood doses over 2 Gy could lead to bone marrow depression). Currently, there is no established agreement for the selection of radioiodine dosage. Historically, the empiric approach, based on clinical and biochemical data, has been recommended. Nevertheless, this method may not be associated with optimal outcomes. On the other hand, the dosimetric approach attempts to determine the maximum allowable activity to be administered, establishing its biokinetics by a diagnostic 131 I study. The methodology may be modified to further individualized treatment, however it requires validation. Biological dosimetry provides an independent measure of radiotherapy effect, as such it might aid in the validation process. Nonetheless, biological dosimetry has traditionally been applied in cases of external and accidental overexposure to ionizing radiation. Accordingly, it is mandatory to assess its value in medical internal incorporations (main objective of the present study). The applied treatment strategy comprises whole body dose assessment by biological and internal dosimetry in order to administer a personalized therapeutic activity. Overall, 20 patients with differentiated thyroid carcinoma were included in the study. For biological dosimetry

A quality assurance system for personal monitoring in Ireland: experience to date and transition from EN 45001 to ISO/IEC 17025

International Nuclear Information System (INIS)

Currivan, L.; Spain, D.; Rafferty, B.

2002-01-01

Up to 2000 the RPII was the competent authority for approval of dosimetry services operating within Ireland. However the transposition into Irish Law of Council Directive 96/29 Euratom in May 2000 means that dosimetry services operating in Ireland must now attain accreditation to the standard of EN-45001 or its equivalent. To comply with this new legislation the RPII sought accreditation for the Dosimetry Service from the Irish National Accreditation Board (NAB). In accordance with the EN-45000 series of European Standards and the relevant ISO guides NAB tests accuracy of results and accredits organisations as appropriate. In September 2000 accreditation was granted to the Dosimetry Service for individual monitoring of personnel who are occupationally exposed to ionising radiation. The scope of the accreditation covers the evaluation of personal doses, for photon and beta, using TLD. Frequent internal quality audits, together with periodic inter-laboratory test programmes, ensure that these quality standards are maintained. This accreditation fulfils the approval under legislation for dosimetry services. The new standard, ISO/IEC 17025, was introduced by ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) in 1999. This standard was introduced in Ireland by NAB and will be implemented for future assessments. The aim of this paper is to describe the quality system currently operated by the RPII's Dosimetry Service, our practical experience to date, and to outline the transition from EN-45001 to ISO/IEC 17025

Radiochromic film calibration for the RQT9 quality beam

Science.gov (United States)

Costa, K. C.; Gomez, A. M. L.; Alonso, T. C.; Mourao, A. P.

2017-11-01

When ionizing radiation interacts with matter it generates energy deposition. Radiation dosimetry is important for medical applications of ionizing radiation due to the increasing demand for diagnostic radiology and radiotherapy. Different dosimetry methods are used and each one has its advantages and disadvantages. The film is a dose measurement method that records the energy deposition by the darkening of its emulsion. Radiochromic films have a little visible light sensitivity and respond better to ionizing radiation exposure. The aim of this study is to obtain the resulting calibration curve by the irradiation of radiochromic film strips, making it possible to relate the darkening of the film with the absorbed dose, in order to measure doses in experiments with X-ray beam of 120 kV, in computed tomography (CT). Film strips of GAFCHROMIC XR-QA2 were exposed according to RQT9 reference radiation, which defines an X-ray beam generated from a voltage of 120 kV. Strips were irradiated in "Laboratório de Calibração de Dosímetros do Centro de Desenvolvimento da Tecnologia Nuclear" (LCD / CDTN) at a dose range of 5-30 mGy, corresponding to the range values commonly used in CT scans. Digital images of the irradiated films were analyzed by using the ImageJ software. The darkening responses on film strips according to the doses were observed and they allowed obtaining the corresponding numeric values to the darkening for each specific dose value. From the numerical values of darkening, a calibration curve was obtained, which correlates the darkening of the film strip with dose values in mGy. The calibration curve equation is a simplified method for obtaining absorbed dose values using digital images of radiochromic films irradiated. With the calibration curve, radiochromic films may be applied on dosimetry in experiments on CT scans using X-ray beam of 120 kV, in order to improve CT acquisition image processes.

Hanford External Dosimetry Technical Basis Manual PNL-MA-842

International Nuclear Information System (INIS)

Rathbone, Bruce A.

2007-01-01

The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at Hanford. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with 10 CFR 835, DOELAP, DOE-RL, ORP, PNSO, and Hanford contractor requirements. The dosimetry system is operated by PNNL's Hanford External Dosimetry Program (HEDP) which provides dosimetry services to all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee (HPDAC) which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. Rev. 0 marks the first revision to be released through PNNL's Electronic Records and Information Capture Architecture (ERICA) database. Revision numbers that are whole numbers reflect major revisions typically involving changes to all chapters in the document. Revision numbers that include a decimal fraction reflect minor revisions, usually restricted to selected chapters or selected pages in the document. Revision Log: Rev. 0 (2/25/2005) Major revision and expansion. Rev. 0.1 (3/12/2007) Minor

Hanford External Dosimetry Technical Basis Manual PNL-MA-842

Energy Technology Data Exchange (ETDEWEB)

Rathbone, Bruce A.

2007-03-12

The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at Hanford. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with 10 CFR 835, DOELAP, DOE-RL, ORP, PNSO, and Hanford contractor requirements. The dosimetry system is operated by PNNL’s Hanford External Dosimetry Program (HEDP) which provides dosimetry services to all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee (HPDAC) which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. Rev. 0 marks the first revision to be released through PNNL’s Electronic Records & Information Capture Architecture (ERICA) database. Revision numbers that are whole numbers reflect major revisions typically involving changes to all chapters in the document. Revision numbers that include a decimal fraction reflect minor revisions, usually restricted to selected chapters or selected pages in the document. Revision Log: Rev. 0 (2/25/2005) Major revision and expansion. Rev. 0.1 (3/12/2007) Minor

Implementation of the method air-kerma product area in KAP camera calibration with reference qualities of X-ray series at the SSDL RQR of Mexico

International Nuclear Information System (INIS)

Cejudo, Jesus; Tovar, Victor M.

2013-01-01

The X-Ray machines, at a reference laboratory for the instrument calibration in diagnostic radiology, should compliance with the ISO requirements. Sometimes there is not available as much laboratories as needed in Latin American countries. So this project shows the KAP ionization chamber implementation method using the TRS-457 radiation quality from the IAEA at the SSDL of Mexico. The KAP instruments calibration method consists in doing a substitution comparison using a standard reference with traceability to a primary laboratory and a transmission-monitoring chamber that measures the number of photons of the X-ray primary beam. A KAP chamber calibration requires a special array that consists in collocating the chamber in two different positions of its calibration process. Then, with air kerma-area product coefficient together with a corrected electrometer measure at referential conditions, the patient dosimetry magnitudes are calculated. The dosimetry necessity at hospitals always will be in function of possessing a highly reliable calibration coefficient chamber for making these measures. That dosimetry results will help in reducing the total or partial irradiation emitted to the human body of the patient. This is how stochastic risks will be lessened due to diagnostic studies. The purpose of this project is to have a synergy with calibration for making known that the SSDL of Mexico has the technical capacity to act as a link between primary standard dosimetry laboratories and the ionizing radiation equipment users who require that their KAP chamber have traceability from the primary standard to the user. (author)

IAEA/SSDL intercomparison of calibration factors for therapy level ionization chambers

International Nuclear Information System (INIS)

Lu Jilong; Cheng Jinsheng; Guo Zhaohui; Li Kaibao

2005-01-01

Objective: By participating in IAEA-SSDL intercomparison, a dose to water calibration factor was introduced in order to check the measuring accuracy of 60 Co radiotherapy dose level standard and ensure the reliability and consistency of our calibration. Methods: The authors carried out both air kerma and absorbed dose to water calibrations against 60 Co γ-rays for one of our field class ionization chambers, and sent the results together with the chamber to IAEA dosimetry laboratory for calibration, then IAEA calibrated it and gave the deviation of the intercomparison. Results: The deviation of our air kerma calibration factors is -0.5%, and the deviation of our absorbed dose to water calibration factors is 0.4%. Conclusion: The deviation of calibration factors between IAEA and SSDL should be no more than ±1.5%. Therefore, the result of this intercomparison is considered satisfactory. (authors)

Development of transfer standard devices for ensuring the accurate calibration of ultrasonic physical therapy machines in clinical use

International Nuclear Information System (INIS)

Hekkenberg, R T; Richards, A; Beissner, K; Zeqiri, B; Prout, G; Cantrall, Ch; Bezemer, R A; Koch, Ch; Hodnett, M

2004-01-01

Physical therapy ultrasound is widely applied to patients. However, many devices do not comply with the relevant standard stating that the actual power output shall be within ±20% of the device indication. Extreme cases have been reported: from delivering effectively no ultrasound or operating at maximum power at all powers indicated. This can potentially lead to patient injury as well as mistreatment. The present European (EC) project is an ongoing attempt to improve the quality of the treatment of patients being treated with ultrasonic physical-therapy. A Portable ultrasound Power Standard (PPS) is being developed and accurately calibrated. The PPS includes: Ultrasound transducers (including one exhibiting an unusual output) and a driver for the ultrasound transducers that has calibration and proficiency test functions. Also included with the PPS is a Cavitation Detector to determine the onset of cavitation occurring within the propagation medium. The PPS will be suitable for conducting in-the-field accreditation (proficiency testing and calibration). In order to be accredited it will be important to be able to show traceability of the calibration, the calibration process and qualification of testing staff. The clinical user will benefit from traceability because treatments will be performed more reliably

Does the accreditation of private dental practices work? Time to rethink how accreditation can improve patient safety.

Science.gov (United States)

Jean, Gillian

2017-10-09

Accreditation to demonstrate engagement with the National Safety and Quality Health Service Standards (Standards) is compulsory for most hospital and healthcare settings, but to date remains voluntary for private dental practices (PDPs). The regulatory framework governing the dental profession lacks a proactive element to drive improvements in quality and safety of care, and an accreditation scheme can strengthen existing regulation. The current model of accreditation operating in accordance with the Australian Health Service Safety and Quality Accreditation Scheme (Scheme) is based on the Standards, which were written for a hospital model of healthcare service. The majority of PDPs are small office-based businesses with clear leadership structure and employing six staff or fewer. The Scheme is overly bureaucratic given the simplicity of the PDP business model. This article considers whether accreditation has a proven track record of improving quality of service and offers opinions about how a more appropriate safety management program for PDPs may look. What is known about the topic? There has been minimal research about the impact of accreditation schemes in improving patient safety in PDP. What does this paper add? This paper proposes a redesign of the Scheme to make it more relevant to PDPs. The paper offers strategies to minimise duplication of purpose between accreditation and existing legislation; and to strengthen critical elements of accreditation to improve effects on patient safety. What are the implications for practitioners? A redesigned accreditation scheme will support dental practitioners to implement a quality assurance system with improved efficiency, reduced administrative burden, and optimised patient safety.

Dosimetry characteristics of the Leksell gamma knife for stereotactic radiosurgery

International Nuclear Information System (INIS)

Wu, A.; Lindner, G.; Maitz, A.; Smarra, N.; Turco, R.F.; Kalend, A.M.; Lunsford, L.D.; Flickinger, J.C.; Bloomer, W.D.

1988-01-01

Gamma knife radiosurgery refers to the treatment procedure that delivers very high dose to a small brain lesion with 201 highly focused beams of Co-60. The hemispheric array of these multiple sources with the sizes of beams ranging from 4, 8, 14, to 18 mm makes the determination of dosimetry characteristics of the radiation field very complex. This paper describes the structures, operations, and dose characteristics of gamma knife. Dosimetry measurements were made using ion chamber, TLD, diode, and films to calibrate the dose outputs of the combination of 201 beams of 4, 8, 14, or 18 mm in diameter irradiating from various directions. Results of measured isodose distribution and dose profiles for the various diameter beams are also presented

Assessment of national dosimetry quality audits results for teletherapy machines from 1989 to 2015.

Science.gov (United States)

Muhammad, Wazir; Ullah, Asad; Mahmood, Khalid; Matiullah

2016-01-01

The purpose of this study was to ensure accuracy in radiation dose delivery, external dosimetry quality audit has an equal importance with routine dosimetry performed at clinics. To do so, dosimetry quality audit was organized by the Secondary Standard Dosimetry Laboratory (SSDL) of Pakistan Institute of Nuclear Science and Technology (PINSTECH) at the national level to investigate and minimize uncertainties involved in the measurement of absorbed dose, and to improve the accuracy of dose measurement at different radiotherapy hospitals. A total of 181 dosimetry quality audits (i.e., 102 of Co-60 and 79 of linear accelerators) for teletherapy units installed at 22 different sites were performed from 1989 to 2015. The percent deviation between users’ calculated/stated dose and evaluated dose (in the result of on-site dosimetry visits) were calculated and the results were analyzed with respect to the limits of ± 2.5% (ICRU "optimal model") ± 3.0% (IAEA on-site dosimetry visits limit) and ± 5.0% (ICRU minimal or "lowest acceptable" model). The results showed that out of 181 total on-site dosimetry visits, 20.44%, 16.02%, and 4.42% were out of acceptable limits of ± 2.5% ± 3.0%, and ± 5.0%, respectively. The importance of a proper ongoing quality assurance program, recommendations of the followed protocols, and properly calibrated thermometers, pressure gauges, and humidity meters at radiotherapy hospitals are essential in maintaining consistency and uniformity of absorbed dose measurements for precision in dose delivery.

IS 2010 and ABET Accreditation: An Analysis of ABET-Accredited Information Systems Programs

Science.gov (United States)

Saulnier, Bruce; White, Bruce

2011-01-01

Many strong forces are converging on information systems academic departments. Among these forces are quality considerations, accreditation, curriculum models, declining/steady student enrollments, and keeping current with respect to emerging technologies and trends. ABET, formerly the Accrediting Board for Engineering and Technology, is at…

Conventional radiation-biological dosimetry using frequencies of unstable chromosome aberrations

International Nuclear Information System (INIS)

Ramalho, Adriana T.; Costa, Maria Lucia P.; Oliveira, Monica S.

1998-01-01

Frequency of chromosome aberrations detected by conventional cytogenetics is a very useful parameter in biological radiodosimetry. It can be used for estimating absorbed doses in individuals working with radioactive sources and individuals accidentally exposed to radiation. In the first case subjects wear physical dosimeters as a routine safety habit. The laboratory at the Institute of Radioprotection and Dosimetry (IRD, Brazil) has been using conventional cytogenetic analysis to complement data obtained by physical dosimetry since 1983. Until now, more than one hundred cases were investigated where individual physical dosimeters detected occupational exposure (above the safety limits allowed). In total, only 34% of these cases were confirmed by conventional cytogenetic dosimetry. Also, conventional cytogenetic analysis following the radiation accident of Goiania (Brazil) in 1987 have been used. Peripheral lymphocytes from 129 exposed or potentially exposed individuals were analyzed for the frequencies of unstable chromosomal aberrations (dicentrics, centric rings and acentrics fragments) to estimate absorbed radiation doses. During the emergency period, doses were estimated to help immediate medical treatment using in vitro calibration curves produced before the accident. Later on, doses were assessed once more using new in vitro calibration curves. A drawback of this technique is that unstable aberrations are lost after exposure. To investigate the mean lifespan of lymphocytes containing dicentric and ring aberrations, we have followed 15 victims of the Goiania accident over all these years. Results suggest that the disappearance of unstable aberrations is dose-dependent. This could explain the variation in the results found among studies in this field