A Fourier analysis on the maximum acceptable grid size for discrete proton beam dose calculation

International Nuclear Information System (INIS)

Li, Haisen S.; Romeijn, H. Edwin; Dempsey, James F.

2006-01-01

We developed an analytical method for determining the maximum acceptable grid size for discrete dose calculation in proton therapy treatment plan optimization, so that the accuracy of the optimized dose distribution is guaranteed in the phase of dose sampling and the superfluous computational work is avoided. The accuracy of dose sampling was judged by the criterion that the continuous dose distribution could be reconstructed from the discrete dose within a 2% error limit. To keep the error caused by the discrete dose sampling under a 2% limit, the dose grid size cannot exceed a maximum acceptable value. The method was based on Fourier analysis and the Shannon-Nyquist sampling theorem as an extension of our previous analysis for photon beam intensity modulated radiation therapy [J. F. Dempsey, H. E. Romeijn, J. G. Li, D. A. Low, and J. R. Palta, Med. Phys. 32, 380-388 (2005)]. The proton beam model used for the analysis was a near mono-energetic (of width about 1% the incident energy) and monodirectional infinitesimal (nonintegrated) pencil beam in water medium. By monodirection, we mean that the proton particles are in the same direction before entering the water medium and the various scattering prior to entrance to water is not taken into account. In intensity modulated proton therapy, the elementary intensity modulation entity for proton therapy is either an infinitesimal or finite sized beamlet. Since a finite sized beamlet is the superposition of infinitesimal pencil beams, the result of the maximum acceptable grid size obtained with infinitesimal pencil beam also applies to finite sized beamlet. The analytic Bragg curve function proposed by Bortfeld [T. Bortfeld, Med. Phys. 24, 2024-2033 (1997)] was employed. The lateral profile was approximated by a depth dependent Gaussian distribution. The model included the spreads of the Bragg peak and the lateral profiles due to multiple Coulomb scattering. The dependence of the maximum acceptable dose grid size on the

Relationship between Individual External Doses, Ambient Dose Rates and Individuals' Activity-Patterns in Affected Areas in Fukushima following the Fukushima Daiichi Nuclear Power Plant Accident.

Directory of Open Access Journals (Sweden)

Wataru Naito

Full Text Available The accident at Fukushima Daiichi Nuclear Power Plant on March 11, 2011, released radioactive material into the atmosphere and contaminated the land in Fukushima and several neighboring prefectures. Five years after the nuclear disaster, the radiation levels have greatly decreased due to physical decay, weathering, and decontamination operations in Fukushima. The populations of 12 communities were forced to evacuate after the accident; as of March 2016, the evacuation order has been lifted in only a limited area, and permanent habitation is still prohibited in most of the areas. In order for the government to lift the evacuation order and for individuals to return to their original residential areas, it is important to assess current and future realistic individual external doses. Here, we used personal dosimeters along with the Global Positioning System and Geographic Information System to understand realistic individual external doses and to relate individual external doses, ambient doses, and activity-patterns of individuals in the affected areas in Fukushima. The results showed that the additional individual external doses were well correlated to the additional ambient doses based on the airborne monitoring survey. The results of linear regression analysis suggested that the additional individual external doses were on average about one-fifth that of the additional ambient doses. The reduction factors, which are defined as the ratios of the additional individual external doses to the additional ambient doses, were calculated to be on average 0.14 and 0.32 for time spent at home and outdoors, respectively. Analysis of the contribution of various activity patterns to the total individual external dose demonstrated good agreement with the average fraction of time spent daily in each activity, but the contribution due to being outdoors varied widely. These results are a valuable contribution to understanding realistic individual external doses

Dose coefficients for individual occupationally exposed

International Nuclear Information System (INIS)

2005-11-01

This Regulation refers to the requirements of the Regulation CNEN-NN.3.01, 'Basic Act of Radiological Protection', aiming its application to the dose calculation, with purposes of conformity verification with limits and restrictions of doses and level of reference for individual occupationally exposed, according to the express in its section 5

Savannah River Site radioiodine atmospheric releases and offsite maximum doses

International Nuclear Information System (INIS)

Marter, W.L.

1990-01-01

Radioisotopes of iodine have been released to the atmosphere from the Savannah River Site since 1955. The releases, mostly from the 200-F and 200-H Chemical Separations areas, consist of the isotopes, I-129 and 1-131. Small amounts of 1-131 and 1-133 have also been released from reactor facilities and the Savannah River Laboratory. This reference memorandum was issued to summarize our current knowledge of releases of radioiodines and resultant maximum offsite doses. This memorandum supplements the reference memorandum by providing more detailed supporting technical information. Doses reported in this memorandum from consumption of the milk containing the highest I-131 concentration following the 1961 1-131 release incident are about 1% higher than reported in the reference memorandum. This is the result of using unrounded 1-131 concentrations of I-131 in milk in this memo. It is emphasized here that this technical report does not constitute a dose reconstruction in the same sense as the dose reconstruction effort currently underway at Hanford. This report uses existing published data for radioiodine releases and existing transport and dosimetry models

Prediction of the maximum dosage to man from the fallout of nuclear devices V. Estimation of the maximum dose from internal emitters in aquatic food supply

International Nuclear Information System (INIS)

Tamplin, A.R.; Fisher, H.L.; Chapman, W.H.

1968-01-01

A method is described for estimating the maximum internal dose that could result from the radionuclides released to an aquatic environment. By means of this analysis one can identify the nuclides that could contribute most to the internal dose, and determine the contribution of each nuclide to the total dose. The calculations required to estimate the maximum dose to an infant's bone subsequent to the construction of a sea-level canal are presented to illustrate the overall method. The results are shown to serve the basic aims of preshot rad-safe analysis and of guidance for postshot documentation. The usefulness of the analysis in providing guidance for device design is further pointed out. (author)

Individualized Dose Prescription for Hypofractionation in Advanced Non-Small-Cell Lung Cancer Radiotherapy: An in silico Trial

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, Aswin L.; Troost, Esther G.C.; Huizenga, Henk; Kaanders, Johannes H.A.M. [Radboud University Nijmegen Medical Centre, Department of Radiation Oncology, Nijmegen (Netherlands); Bussink, Johan, E-mail: j.bussink@rther.umcn.nl [Radboud University Nijmegen Medical Centre, Department of Radiation Oncology, Nijmegen (Netherlands)

2012-08-01

Purpose: Local tumor control and outcome remain poor in patients with advanced non-small-cell lung cancer (NSCLC) treated by external beam radiotherapy. We investigated the therapeutic gain of individualized dose prescription with dose escalation based on normal tissue dose constraints for various hypofractionation schemes delivered with intensity-modulated radiation therapy. Methods and Materials: For 38 Stage III NSCLC patients, the dose level of an existing curative treatment plan with standard fractionation (66 Gy) was rescaled based on dose constraints for the lung, spinal cord, esophagus, brachial plexus, and heart. The effect on tumor total dose (TTD) and biologic tumor effective dose in 2-Gy fractions (TED) corrected for overall treatment time (OTT) was compared for isotoxic and maximally tolerable schemes given in 15, 20, and 33 fractions. Rescaling was accomplished by altering the dose per fraction and/or the number of fractions while keeping the relative dose distribution of the original treatment plan. Results: For 30 of the 38 patients, dose escalation by individualized hypofractionation yielded therapeutic gain. For the maximally tolerable dose scheme in 33 fractions (MTD{sub 33}), individualized dose escalation resulted in a 2.5-21% gain in TTD. In the isotoxic schemes, the number of fractions could be reduced with a marginal increase in TED. For the maximally tolerable dose schemes, the TED could be escalated up to 36.6%, and for all patients beyond the level of the isotoxic and the MTD{sub 33} schemes (range, 3.3-36.6%). Reduction of the OTT contributed to the therapeutic gain of the shortened schemes. For the maximally tolerable schemes, the maximum esophageal dose was the dominant dose-limiting constraint in most patients. Conclusions: This modeling study showed that individualized dose prescription for hypofractionation in NSCLC radiotherapy, based on scaling of existing treatment plans up to normal tissue dose constraints, enables dose

Dose to individuals: who and how

International Nuclear Information System (INIS)

Till, J.E.

2003-01-01

In 2002 the Main Commission established a Task Group on 'Characterisation of the Individual for the Purpose of Assessing compliance with Dose Constraints'. This paper highlights some of the Task Group's key recommendations and provides a basis for discussion for break out sessions that follow. Although the title indicates that I will address 'who' the individual is and 'how' the individual is characterised, I thought it wise to first mention 'why' we are concerned about the individual in the consolidated recommendations. Here are a few reasons why characterising the individual is important. First, the proposed consolidated recommendations place greater emphasis on individual-related criteria rather than societal or collective dose based criteria. This has been explained in the earlier presentation by Dr. Clarke. Also, it is necessary to update guidance on how to identify and characterise critical groups and individuals since this topic has not been thoroughly addressed by The International Commission on Radiological Protection (ICRP) since the publication of ICRP 43 (ICRP, 1985). Finally, the report intends to address additional conceptual and technical issues related to determining compliance with constraints and making decisions in emergency situations. The scope of the Task Group's work places emphasis on prospective exposure situations. It does not address medical and occupational exposures. (author)

An investigation of rugby scrimmaging posture and individual maximum pushing force.

Science.gov (United States)

Wu, Wen-Lan; Chang, Jyh-Jong; Wu, Jia-Hroung; Guo, Lan-Yuen

2007-02-01

Although rugby is a popular contact sport and the isokinetic muscle torque assessment has recently found widespread application in the field of sports medicine, little research has examined the factors associated with the performance of game-specific skills directly by using the isokinetic-type rugby scrimmaging machine. This study is designed to (a) measure and observe the differences in the maximum individual pushing forward force produced by scrimmaging in different body postures (3 body heights x 2 foot positions) with a self-developed rugby scrimmaging machine and (b) observe the variations in hip, knee, and ankle angles at different body postures and explore the relationship between these angle values and the individual maximum pushing force. Ten national rugby players were invited to participate in the examination. The experimental equipment included a self-developed rugby scrimmaging machine and a 3-dimensional motion analysis system. Our results showed that the foot positions (parallel and nonparallel foot positions) do not affect the maximum pushing force; however, the maximum pushing force was significantly lower in posture I (36% body height) than in posture II (38%) and posture III (40%). The maximum forward force in posture III (40% body height) was also slightly greater than for the scrum in posture II (38% body height). In addition, it was determined that hip, knee, and ankle angles under parallel feet positioning are factors that are closely negatively related in terms of affecting maximum pushing force in scrimmaging. In cross-feet postures, there was a positive correlation between individual forward force and hip angle of the rear leg. From our results, we can conclude that if the player stands in an appropriate starting position at the early stage of scrimmaging, it will benefit the forward force production.

Calculate the maximum expected dose for technical radio physicists a cobalt machine

International Nuclear Information System (INIS)

Avila Avila, Rafael; Perez Velasquez, Reytel; Gonzalez Lapez, Nadia

2009-01-01

Considering the daily operations carried out by technicians Radiophysics Medical Service Department of Radiation Oncology Hospital V. General Teaching I. Lenin in the city of Holguin, during a working week (Between Monday and Friday) as an important element in calculating the maximum expected dose (MDE). From the exponential decay law which is subject the source activity, we propose corrections to the cumulative doses in the weekly period, leading to obtaining a formula which takes into a cumulative dose during working days and sees no dose accumulation of rest days (Saturday and Sunday). The estimate factor correction is made from a power series expansion convergent is truncated at the n-th term coincides with the week period for which you want to calculate the dose. As initial condition is adopted ambient dose equivalent rate as a given, which allows estimate MDE in the moments after or before this. Calculations were proposed use of an Excel spreadsheet that allows simple and accessible processing the formula obtained. (author)

Application of maximum values for radiation exposure and principles for the calculation of radiation doses

International Nuclear Information System (INIS)

2007-08-01

The guide presents the definitions of equivalent dose and effective dose, the principles for calculating these doses, and instructions for applying their maximum values. The limits (Annual Limit on Intake and Derived Air Concentration) derived from dose limits are also presented for the purpose of monitoring exposure to internal radiation. The calculation of radiation doses caused to a patient from medical research and treatment involving exposure to ionizing radiation is beyond the scope of this ST Guide

Estimation of maximum credible atmospheric radioactivity concentrations and dose rates from nuclear tests

International Nuclear Information System (INIS)

Telegadas, K.

1979-01-01

A simple technique is presented for estimating maximum credible gross beta air concentrations from nuclear detonations in the atmosphere, based on aircraft sampling of radioactivity following each Chinese nuclear test from 1964 to 1976. The calculated concentration is a function of the total yield and fission yield, initial vertical radioactivity distribution, time after detonation, and rate of horizontal spread of the debris with time. calculated maximum credible concentrations are compared with the highest concentrations measured during aircraft sampling. The technique provides a reasonable estimate of maximum air concentrations from 1 to 10 days after a detonation. An estimate of the whole-body external gamma dose rate corresponding to the maximum credible gross beta concentration is also given. (author)

Should repository release criteria be based on collective dose, release limits, or individual doses?

International Nuclear Information System (INIS)

Channell, J.K.; Neill, R.H.

1999-01-01

The advantages and disadvantages of using each of 3 alternative methods (collective dose, release limits, and individual dose) as release criteria for determining long-term high level or transuranic waste repository performance of naturally occurring releases or man-made intrusions are evaluated. Each of the alternative approaches have positive aspects and each has uncertainties that require some arbitrary assumptions. A comparison of the numerical results from evaluating the three alternatives at WIPP leads to the conclusion that a collective dose is preferable because it is more site specific and allows consideration of the full effects of human intrusion. The main objection to release limits is they do not use site specific criteria to determine the radiological effect on local and regional populations. Individual dose criteria used and recommended in the United States have ignored doses to drillers and the public from wastes brought to the surface by human intrusion because these doses can be greater than acceptable limits. Also, there is disagreement about defining the location and lifestyle of the individual

Georgia fishery study: implications for dose calculations

International Nuclear Information System (INIS)

Turcotte, M.D.S.

1983-01-01

Fish consumption will contribute a major portion of the estimated individual and population doses from L-Reactor liquid releases and Cs-137 remobilization in Steel Creek. It is therefore important that the values for fish consumption used in dose calculations be as realistic as possible. Since publication of the L-Reactor Environmental Information Document (EID), data have become available on sport fishing in the Savannah River. These data provide SRP with site-specific sport fish harvest and consumption values for use in dose calculations. The Georgia fishery data support the total population fish consumption and calculated dose reported in the EID. The data indicate, however, that both the EID average and maximum individual fish consumption have been underestimated, although each to a different degree. The average fish consumption value used in the EID is approximately 3% below the lower limit of the fish consumption range calculated using the Georgia data. A fish consumption value of 11.3 kg/yr should be used to recalculate dose to the average individual from L-Reactor restart. Maximum fish consumption in the EID has been underestimated by approximately 60%, and doses to the maximum individual should also be recalculated. Future dose calculations should utilize an average fish consumption value of 11.3 kg/yr, and a maximum fish consumption value of 34 kg/yr

SU-E-T-578: On Definition of Minimum and Maximum Dose for Target Volume

Energy Technology Data Exchange (ETDEWEB)

Gong, Y; Yu, J; Xiao, Y [Thomas Jefferson University Hospital, Philadelphia, PA (United States)

2015-06-15

Purpose: This study aims to investigate the impact of different minimum and maximum dose definitions in radiotherapy treatment plan quality evaluation criteria by using tumor control probability (TCP) models. Methods: Dosimetric criteria used in RTOG 1308 protocol are used in the investigation. RTOG 1308 is a phase III randomized trial comparing overall survival after photon versus proton chemoradiotherapy for inoperable stage II-IIIB NSCLC. The prescription dose for planning target volume (PTV) is 70Gy. Maximum dose (Dmax) should not exceed 84Gy and minimum dose (Dmin) should not go below 59.5Gy in order for the plan to be “per protocol” (satisfactory).A mathematical model that simulates the characteristics of PTV dose volume histogram (DVH) curve with normalized volume is built. The Dmax and Dmin are noted as percentage volumes Dη% and D(100-δ)%, with η and d ranging from 0 to 3.5. The model includes three straight line sections and goes through four points: D95%= 70Gy, Dη%= 84Gy, D(100-δ)%= 59.5 Gy, and D100%= 0Gy. For each set of η and δ, the TCP value is calculated using the inhomogeneously irradiated tumor logistic model with D50= 74.5Gy and γ50=3.52. Results: TCP varies within 0.9% with η; and δ values between 0 and 1. With η and η varies between 0 and 2, TCP change was up to 2.4%. With η and δ variations from 0 to 3.5, maximum of 8.3% TCP difference is seen. Conclusion: When defined maximum and minimum volume varied more than 2%, significant TCP variations were seen. It is recommended less than 2% volume used in definition of Dmax or Dmin for target dosimetric evaluation criteria. This project was supported by NIH grants U10CA180868, U10CA180822, U24CA180803, U24CA12014 and PA CURE Grant.

SU-E-T-578: On Definition of Minimum and Maximum Dose for Target Volume

International Nuclear Information System (INIS)

Gong, Y; Yu, J; Xiao, Y

2015-01-01

Purpose: This study aims to investigate the impact of different minimum and maximum dose definitions in radiotherapy treatment plan quality evaluation criteria by using tumor control probability (TCP) models. Methods: Dosimetric criteria used in RTOG 1308 protocol are used in the investigation. RTOG 1308 is a phase III randomized trial comparing overall survival after photon versus proton chemoradiotherapy for inoperable stage II-IIIB NSCLC. The prescription dose for planning target volume (PTV) is 70Gy. Maximum dose (Dmax) should not exceed 84Gy and minimum dose (Dmin) should not go below 59.5Gy in order for the plan to be “per protocol” (satisfactory).A mathematical model that simulates the characteristics of PTV dose volume histogram (DVH) curve with normalized volume is built. The Dmax and Dmin are noted as percentage volumes Dη% and D(100-δ)%, with η and d ranging from 0 to 3.5. The model includes three straight line sections and goes through four points: D95%= 70Gy, Dη%= 84Gy, D(100-δ)%= 59.5 Gy, and D100%= 0Gy. For each set of η and δ, the TCP value is calculated using the inhomogeneously irradiated tumor logistic model with D50= 74.5Gy and γ50=3.52. Results: TCP varies within 0.9% with η; and δ values between 0 and 1. With η and η varies between 0 and 2, TCP change was up to 2.4%. With η and δ variations from 0 to 3.5, maximum of 8.3% TCP difference is seen. Conclusion: When defined maximum and minimum volume varied more than 2%, significant TCP variations were seen. It is recommended less than 2% volume used in definition of Dmax or Dmin for target dosimetric evaluation criteria. This project was supported by NIH grants U10CA180868, U10CA180822, U24CA180803, U24CA12014 and PA CURE Grant

Dose constraints and guidance for exposure of individuals knowingly and willingly helping in the support and comfort of individuals undergoing medical exposure

International Nuclear Information System (INIS)

Jansen, J. Th M.; Zoetelief, J.

2006-01-01

The council of the European Union (EU) has adopted directive 97/43/ EURATOM that states that Member States shall ensure that dose constraints are established for exposure of those individuals (voluntary helpers) knowingly and willingly helping patients undergoing medical diagnosis or treatment. This study investigates for which medical diagnoses and treatments voluntary helpers are active. It provides a rough estimation of the effective dose to the voluntary helper for various applications. It summarises the dose constraints established in various EU Member States. Voluntary helpers are especially active in paediatric radiology and in nuclear medicine for both diagnostic and for therapeutic purposes. No voluntary helpers are active during radiotherapy. Voluntary helpers are commonly one of the parents, relatives or friends of the patient. In The Netherlands, the highest effective dose to voluntary helpers of ∼2.3 mSv is found for therapy of patients younger than 1 y with metaiodobenzylguanidine labelled with 131 I. Effective doses to voluntary helpers in paediatric radiology are, generally, quite small, i.e. lower than several tens of μSv at maximum without wearing protective clothing. (authors)

Monitoring of individual doses and its information management system for CAEP's employees

International Nuclear Information System (INIS)

Wei Xiye; Lei Jiarong; Yuan Yonggang; Zhao Lin; Zhao Minzhi; Cui Gaoxian

2007-01-01

Employees' individual dose is very important to radiation workers, this paper introduces the monitoring of individual doses for the employees of CAEP in brief. A mass of employees' individual dose information records needed for being disposed, the data management software IDDMS for individual dose was developed. This paper describes the database structure, main modules, statistic and printing functions in this program. Based on much experience of many years in data management of individual dose, this program is developed using the object-oriented language Visual Foxpro 6.0. Meanwhile, it had been tested for several months. The results show that this software can be used directly for daily management of individual dose, and report forms of individual dose can also be printed easily for the related superior department. (authors)

Values of dose and individual of a individual thermoluminescent dosimeter submitted to x and gamma radiations

International Nuclear Information System (INIS)

Moraes, Cassiana Viccari de; Pela, Carlos Alberto

2001-01-01

The individual monitoring provides information for the control of exposures, and estimates the dose received by individuals. This is an essential tool in personal dosimetry. It's based on a radiation protection concept, allowing an individual exposure control, besides guaranteeing that the dose restrictions will not be exceeded. Usually, the dose monitoring is performed by using an individual dosemeter placed on a representative position of the most exposed point on the thoracic surface. The dosemeter, which is analyzed in the present work, is made of three CaSO 4 -Dy thermoluminescent detectors, plastic filters, copper and copper-lead, mounted in an acrylic support. The dose received by on each detector, which forms the dosemeter, is related according to their energetic curve dependence. The dose amount is calculated from these curves by using an algorithm, and it was taken in to consideration the detector calibration and thermoluminescent responses, due to the x and g radiation exposure. That algorithm has the capacity to determine the energies that were irradiated the detector. Therefore, to aid the service in the moment of evaluate the dose received by the individual and where it is coming from. The algorithm has provided individual dose value H x , defined as operational quantity for photons adopted in the Brazilian Metric System. The algorithm can determine two dose values and such values have been analyzed according to the kind of irradiated energy on the dosimeter and it has shown that both values are within established limits by Instituto de Radioprotecao e Dosimetria (IRD). (author)

Monitoring and dose recording for the individual

International Nuclear Information System (INIS)

1988-01-01

This document specifies the conditions under which monitoring of individuals is required. For workers identified as Atomic Radiation Workers, determination of dose or exposure must be made. In circumstances where personal monitoring techniques are impractical, doses and exposures may be estimated by non-personal monitoring techniques. For workers not identified as Atomic Radiation Workers, licensees must be able to demonstrate that there is no reasonable potential for accumulating radiation doses or exposures in excess of regulatory limits. (L.L.)

Application of maximum values for radiation exposure and principles for the calculation of radiation dose

International Nuclear Information System (INIS)

2000-01-01

The guide sets out the mathematical definitions and principles involved in the calculation of the equivalent dose and the effective dose, and the instructions concerning the application of the maximum values of these quantities. further, for monitoring the dose caused by internal radiation, the guide defines the limits derived from annual dose limits (the Annual Limit on Intake and the Derived Air Concentration). Finally, the guide defines the operational quantities to be used in estimating the equivalent dose and the effective dose, and also sets out the definitions of some other quantities and concepts to be used in monitoring radiation exposure. The guide does not include the calculation of patient doses carried out for the purposes of quality assurance

Application of maximum values for radiation exposure and principles for the calculation of radiation dose

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

The guide sets out the mathematical definitions and principles involved in the calculation of the equivalent dose and the effective dose, and the instructions concerning the application of the maximum values of these quantities. further, for monitoring the dose caused by internal radiation, the guide defines the limits derived from annual dose limits (the Annual Limit on Intake and the Derived Air Concentration). Finally, the guide defines the operational quantities to be used in estimating the equivalent dose and the effective dose, and also sets out the definitions of some other quantities and concepts to be used in monitoring radiation exposure. The guide does not include the calculation of patient doses carried out for the purposes of quality assurance.

Maximum tolerated dose in a phase I trial on adaptive dose painting by numbers for head and neck cancer

International Nuclear Information System (INIS)

Madani, Indira; Duprez, Fréderic; Boterberg, Tom; Van de Wiele, Christophe; Bonte, Katrien; Deron, Philippe; De Gersem, Werner; Coghe, Marc; De Neve, Wilfried

2011-01-01

Purpose: To determine the maximum tolerated dose (MTD) in a phase I trial on adaptive dose-painting-by-numbers (DPBN) for non-metastatic head and neck cancer. Materials and methods: Adaptive intensity-modulated radiotherapy was based on voxel intensity of pre-treatment and per-treatment [ 18 F]fluoro-2-deoxy-D-glucose positron emission tomography ( 18 F-FDG-PET) scans. Dose was escalated to a median total dose of 80.9 Gy in the high-dose clinical target volume (dose level I) and 85.9 Gy in the gross tumor volume (dose level II). The MTD would be reached, if ⩾33% of patients developed any grade ⩾4 toxicity (DLT) up to 3 months follow-up. Results: Between February 2007 and August 2009, seven patients at dose level I and 14 at dose level II were treated. All patients completed treatment without interruption. At a median follow-up for surviving patients of 38 (dose level I) and 22 months (dose level II) there was no grade ⩾4 toxicity during treatment and follow-up but six cases of mucosal ulcers at latency of 4–10 months, of which five (36%) were observed at dose level II. Mucosal ulcers healed spontaneously in four patients. Conclusions: Considering late mucosal ulcers as DLT, the MTD of a median dose of 80.9 Gy has been reached in our trial.

Hazards and maximum permissible doses of radiation for man

International Nuclear Information System (INIS)

Walinder, G.

1977-11-01

Maximum permissible dose levels are primarely based on risks for genetic damage and cancer. The reason for this is the observation that such late effects of radiation seem to arise even after doses that are to low to give rise to acute effects. In contrast to the tumour incidence found in irradiated human populations no genetic effects of radiation have been observed in man. This does not mean that genetic effects have not been induced but that it has been impossible to find an increase or to discern them among all the congenital defects, that can not be ascribed to the irradiation. As a consequence, the radiological risk estimation has been concentrated on the hazard of malignant diseases. Tumour risks are generally expressed as excess rates of incidence and mortality per million persons per rem. These figures are, however, not obtained from direct epidemiological observations but have been calculated from such data under the assumption of a linear relationship between effect and radiation dose. This formal extrapolation of observed data involves an uncertainty which, of course, is proportionately greater for the calculated effects in the millirem range. However, although the calculated tumour risks can not be said to be founded on direct scientific evidence, there are scientific reasons to believe that the figures derived from the formal extrapolations constitute an upper limit of possible ri02050

Annual individual doses for personnel dealing with ionizing radiation sources

International Nuclear Information System (INIS)

Poplavskij, K.K.

1982-01-01

Data on annual individual doses for personnel of national economy enterprises, research institutes, high schools, medical establishments dealing with ionizing radiation sources are presented. It is shown that radiation dose for the personnel constitutes only shares of standards established by sanitary legislation. Numeral values of individual doses of the personnel are determined by the type, character and scope of using ionizing radiation sources

Evaluating the maximum patient radiation dose in cardiac interventional procedures

International Nuclear Information System (INIS)

Kato, M.; Chida, K.; Sato, T.; Oosaka, H.; Tosa, T.; Kadowaki, K.

2011-01-01

Many of the X-ray systems that are used for cardiac interventional radiology provide no way to evaluate the patient maximum skin dose (MSD). The authors report a new method for evaluating the MSD by using the cumulative patient entrance skin dose (ESD), which includes a back-scatter factor and the number of cine-angiography frames during percutaneous coronary intervention (PCI). Four hundred consecutive PCI patients (315 men and 85 women) were studied. The correlation between the cumulative ESD and number of cine-angiography frames was investigated. The irradiation and overlapping fields were verified using dose-mapping software. A good correlation was found between the cumulative ESD and the number of cine-angiography frames. The MSD could be estimated using the proportion of cine-angiography frames used for the main angle of view relative to the total number of cine-angiography frames and multiplying this by the cumulative ESD. The average MSD (3.0±1.9 Gy) was lower than the average cumulative ESD (4.6±2.6 Gy). This method is an easy way to estimate the MSD during PCI. (authors)

Nuclear medicine external individual occupational doses in Rio de Janeiro

International Nuclear Information System (INIS)

Mauricio, Claudia L.P.; Lima, Ana Luiza S.; Silva, Herica L.R. da; Santos, Denison Souza; Silva, Claudio Ribeiro da

2009-01-01

According to the Brazilian National Database there are about 300 Nuclear Medicine Services (NMS) in Brazil, 44 of them located in the State of Rio de Janeiro (RJ). Individual dose measurements are an important input for the evaluation of occupational exposure in order to demonstrate the effectiveness of radioprotection implementation and to keep individual doses as low as possible. In Brazil, most nuclear medicine (NM) staff is routinely monitored for external dose. The internal committed dose is estimated only in abnormal conditions. This paper makes a statistics analysis of all the RJ NMS annual external occupational doses in year 2005. A study of the evolution of monthly external individual doses higher than 4.00 mSv from 2004 to 2008 is also presented. The number of registered thorax monthly dose higher than 4.0 mSv is increasing, as its value. In this period the highest dose measured reaches 56.9 mSv, in one month, in 2008. About 50% of the annual doses are smaller than the monthly record level of 0.20 mSv. In 2005, around 100 professionals of RJ NMS received annual doses higher than 4.0 mSv, considering only external doses, but no one receives doses higher than 20.0 mSv. Extremities dosimeters are used by about 15% of the staff. In some cases, these doses are more than 10 times higher than the dose in thorax. This study shows the importance to improve radiation protection procedures in NM. (author)

Individual dose monitoring of occupational exposure in nuclear industry system (1991-2000)

International Nuclear Information System (INIS)

Yang Lianzhen; Ma Jizeng; Li Taosheng

2005-01-01

The summary and main results of individual dose monitoring (1990-2000) from occupational exposure in China Nuclear Industry System are presented in this paper. During ten years, the external collective effective dose to workers in seven plants (not uranium mines and processing mills) and institutes is 98.48 person ·Sv, the per capita effective dose is 1.97 mSv. The general situation for individual dose monitoring from internal exposure is also introduced. The annual average committed effective dose is less than 5.0 mSv. The individual dose monitoring results (1991-1992) for occupational exposure from Uranium mines and processing mills are depicted. In the end, the individual dose monitoring data in nuclear industry system are preliminarily analysed. (authors)

Once-daily dosing of saquinavir and low-dose ritonavir in HIV-1-infected individuals: a pharmacokinetic pilot study

NARCIS (Netherlands)

van Heeswijk, R. P.; Veldkamp, A. I.; Mulder, J. W.; Meenhorst, P. L.; Lange, J. M.; Beijnen, J. H.; Hoetelmans, R. M.

2000-01-01

To investigate the steady-state pharmacokinetics of a once-daily dosing regimen of saquinavir soft gelatin capsules in combination with a low dose of ritonavir in HIV-1-infected individuals. Open-label, multi-dose, pharmacokinetic pilot study. Seven HIV-1-infected individuals who were treated with

Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

Energy Technology Data Exchange (ETDEWEB)

Koga, Taeko; Morishima, Hiroshige [Kinki Univ., Atomic Energy Research Institute, Osaka (Japan); Tatsumi, Kusuo [Kinki Univ., Life Science Research Institute, Osaka (Japan); Nakai, Sayaka; Sugahara, Tsutomu [Health Research Foundation, Kyoto (Japan); Yuan Yongling [Labor Hygiene Institute of Hunan Prov. (China); Wei Luxin [Laboratory of Industorial Hygiene, Ministry of Health (China)

2001-01-01

As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: (1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. (2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

International Nuclear Information System (INIS)

Koga, Taeko; Morishima, Hiroshige; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2001-01-01

As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: 1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. 2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

THE RESULTS OF INDIVIDUAL DOSE CONTROL OF HEALTH INSTITUTIONS STAFF

Directory of Open Access Journals (Sweden)

E. N. Shleenkova

2014-01-01

Full Text Available The  work  provides  comparative  assessment  of  the  levels  of  occupational  exposure  of  Saint-Petersburg health institutions staff. The analysis was carried out of the 891 individual doses measurement results which have  being  obtained  during  5  years  investigations  (2009-2013.  The  comparing  of  the  average  annual effective doses was carried out for 4 groups of medical specialists: x-ray laboratory assistant, radiotherapist, radiographer of dental clinics and X-ray surgery staff (surgeons, anesthesiologists and surgical nurses who are working close to irradiation source. It is shown that the annual effective dose average value is about 0.5 mSv for the first three groups of medical specialists. The same value for X-ray surgery staff is 1.6 mSv. Individual  annual  exposure  doses  have  not  exceeded  the  main  dose  limits  required  by  Radiation  Safety Standard 99/2009. The issues are considered of the estimation exactness of the effective dose basing on the results of individual dose equivalent measurement. 

Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

International Nuclear Information System (INIS)

Morishima, Hiroshige; Koga, Taeko; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2000-01-01

As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

Energy Technology Data Exchange (ETDEWEB)

Morishima, Hiroshige; Koga, Taeko [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2000-10-01

As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

Criteria for calculation of effective dose from the individual monitoring; Criterios para calculo de dose efetiva a partir da monitoracao individual

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-11-15

This Regulation refers to the requirements of the Regulation CNEN-NN.3.01. 'Basic Act of Radiological Protection', as expressed in the section 5.9, and its application to the effective dose calculation for individual occupationally exposed. from the internal and external individual monitoring data

Development of sustained and dual drug release co-extrusion formulations for individual dosing.

Science.gov (United States)

Laukamp, Eva Julia; Vynckier, An-Katrien; Voorspoels, Jody; Thommes, Markus; Breitkreutz, Joerg

2015-01-01

In personalized medicine and patient-centered medical treatment individual dosing of medicines is crucial. The Solid Dosage Pen (SDP) allows for an individual dosing of solid drug carriers by cutting them into tablet-like slices. The aim of the present study was the development of sustained release and dual release formulations with carbamazepine (CBZ) via hot-melt co-extrusion for the use in the SDP. The selection of appropriate coat- and core-formulations was performed by adapting the mechanical properties (like tensile strength and E-modulus) for example. By using different excipients (polyethyleneglycols, poloxamers, white wax, stearic acid, and carnauba wax) and drug loadings (30-50%) tailored dissolution kinetics was achieved showing cube root or zero order release mechanisms. Besides a biphasic drug release, the dose-dependent dissolution characteristics of sustained release formulations were minimized by a co-extruded wax-coated formulation. The dissolution profiles of the co-extrudates were confirmed during short term stability study (six months at 21.0 ± 0.2 °C, 45%r.h.). Due to a good layer adhesion of core and coat and adequate mechanical properties (maximum cutting force of 35.8 ± 2.0 N and 26.4 ± 2.8 N and E-modulus of 118.1 ± 8.4 and 33.9 ± 4.5 MPa for the dual drug release and the wax-coated co-extrudates, respectively) cutting off doses via the SDP was precise. While differences of the process parameters (like the barrel temperature) between the core- and the coat-layer resulted in unsatisfying content uniformities for the wax-coated co-extrudates, the content uniformity of the dual drug release co-extrudates was found to be in compliance with pharmacopoeial specification. Copyright © 2015 Elsevier B.V. All rights reserved.

Dose assessment around TR-2 reactor due to maximum credible accident

International Nuclear Information System (INIS)

Turgut, M. H.; Adalioglu, U.; Aytekin, A.

2001-01-01

The revision of safety analysis report of TR-2 research reactor had been initiated in 1995. The whole accident analysis and accepted scenario for maximum credible accident has been revised according to the new safety concepts and the impact to be given to the environment due to this scenario has been assessed. This paper comprises all results of these calculations. The accepted maximum credible accident scenario is the partial blockage of the whole reactor core which resulted in the release of 25% of the core inventory. The DOSER code which uses very conservative modelling of atmospheric distributions were modified for the assessment calculations. Pasquill conditions based on the local weather observations, topography, and building affects were considered. The thyroid and whole body doses for 16 sectors and up to 10 km of distance around CNAEM were obtained. Release models were puff and a prolonged one of two hours of duration. Release fractions for the active isotopes were chosen from literature which were realistic

Dose estimates in Japan following the Chernobyl reactor accident

International Nuclear Information System (INIS)

Togawa, Orihiko; Homma, Toshimitsu; Iijima, Toshinori; Midorikawa, Yuji.

1988-02-01

Estimates have been made of the maximum individual doses and the collective doses in Japan following the Chernobyl reactor accident. Based on the measured data of ground deposition and radionuclide concentrations in air, raw milk, milk on sale and leafy vegetables, the doses from some significant radionuclides were calculated for 5 typical exposure pathways; cloudshine, groundshine, inhalation, ingestion of milk and leafy vegetables. The maximum effective dose equivalents for hypothetical individuals were calculated to be 1.8 mrem for adults, 3.7 mrem for children and 6.0 mrem for infants. The collective effective dose equivalent in Japan was estimated to be 5.8 x 10 4 man · rem; 0.50 mrem of the average dose per capita. (author)

Individual dose control of workers

International Nuclear Information System (INIS)

Keverling Buisman, A.S.

1990-01-01

This publication has the character of a set of recommendations towards in practice working radiation protection specialists who are involved within their company or institute with the organization and performance of measurements in order to control the individual radiation burden caused by external exposition and internal contamination in applying radioactive materials and radiation apparatus. This publication gives information about the practical performance of personnel dosimetry at external exposure with a personnel dosimeter, which is carried on the body. The individual control of internal contamination is a much more complicated task. This publication assumes, with regard to this part, that people who are involved with it have been schooled as a radiation specialist level-3. For this part this publication contains numerical information needed for assessing of the individual effective follow-dose equivalence in occurring cases. A list with data of much used radionuclides is included. Also dosimetric data are presented which may be useful in case of contamination of skin and wounds. (author). 14 refs.; 2 figs.; 17 tabs

Individual-dose distribution for the population in different regions with radioactive contamination

International Nuclear Information System (INIS)

Keirim-Markus, I.B.; Kleshchenko, E.D.; Kushnereva, K.K.

1995-01-01

The reconstruction of individual doses as a result of the Chernobyl accident often relied on the method of EPR measurement from the enamel from extracted teeth. This method was used reliably, with individual confirmations of its indications being obtained. In determining the relatively small irradiation dose to the population, doubts arise because of the fact that the measured dose is often greater than the dose calculated by an indirect method---from external radiation fields at the location and the contents of radionuclides in foods. It is necessary, therefore, to perform an independent check of the results. In this paper, we describe one method for checking the reliability---comparing the measurements of the dose from several teeth in the same individual---in determining the dose from tooth enamel for the population of the Kamensk-Ural region of Sverdlovsk province. This group lived in the zone of passage for the eastern Ural radioactive wake in 1957. The error of the dose determination for different samples was different, since it depends on the mass and quality of the enamel obtained. The results presented show that the method of EPR dosimetry using the enamel of extracted teeth makes it possible to determine quite reliably the individual dose of external radiation from the background up to several Gy of the measurements. Our method compares measurements

Development of a pharmacokinetic‐guided dose individualization strategy for hydroxyurea treatment in children with sickle cell anaemia

Science.gov (United States)

Dong, Min; McGann, Patrick T.; Mizuno, Tomoyuki; Ware, Russell E.

2016-01-01

AIMS Hydroxyurea has emerged as the primary disease‐modifying therapy for patients with sickle cell anaemia (SCA). The laboratory and clinical benefits of hydroxyurea are optimal at maximum tolerated dose (MTD), but the current empirical dose escalation process often takes up to 12 months. The purpose of this study was to develop a pharmacokinetic‐guided dosing strategy to reduce the time required to reach hydroxyurea MTD in children with SCA. Methods Pharmacokinetic (PK) data from the HUSTLE trial (NCT00305175) were used to develop a population PK model using non‐linear mixed effects modelling (nonmem 7.2). A D‐optimal sampling strategy was developed to estimate individual PK and hydroxyurea exposure (area under the concentration–time curve (AUC)). The initial AUC target was derived from HUSTLE clinical data and defined as the mean AUC at MTD. Results PK profiles were best described by a one compartment with Michaelis–Menten elimination and a transit absorption model. Body weight and cystatin C were identified as significant predictors of hydroxyurea clearance. The following clinically feasible sampling times are included in a new prospective protocol: pre‐dose (baseline), 15–20 min, 50–60 min and 3 h after an initial 20 mg kg–1 oral dose. The mean target AUC(0,∞) for initial dose titration was 115 mg l–1 h. Conclusion We developed a PK model‐based individualized dosing strategy for the prospective Therapeutic Response Evaluation and Adherence Trial (TREAT, ClinicalTrials.gov NCT02286154). This approach has the potential to optimize the dose titration of hydroxyurea therapy for children with SCA, such that the clinical benefits at MTD are achieved more quickly. PMID:26615061

Development of a pharmacokinetic-guided dose individualization strategy for hydroxyurea treatment in children with sickle cell anaemia.

Science.gov (United States)

Dong, Min; McGann, Patrick T; Mizuno, Tomoyuki; Ware, Russell E; Vinks, Alexander A

2016-04-01

Hydroxyurea has emerged as the primary disease-modifying therapy for patients with sickle cell anaemia (SCA). The laboratory and clinical benefits of hydroxyurea are optimal at maximum tolerated dose (MTD), but the current empirical dose escalation process often takes up to 12 months. The purpose of this study was to develop a pharmacokinetic-guided dosing strategy to reduce the time required to reach hydroxyurea MTD in children with SCA. Pharmacokinetic (PK) data from the HUSTLE trial (NCT00305175) were used to develop a population PK model using non-linear mixed effects modelling (nonmem 7.2). A D-optimal sampling strategy was developed to estimate individual PK and hydroxyurea exposure (area under the concentration-time curve (AUC)). The initial AUC target was derived from HUSTLE clinical data and defined as the mean AUC at MTD. PK profiles were best described by a one compartment with Michaelis-Menten elimination and a transit absorption model. Body weight and cystatin C were identified as significant predictors of hydroxyurea clearance. The following clinically feasible sampling times are included in a new prospective protocol: pre-dose (baseline), 15-20 min, 50-60 min and 3 h after an initial 20 mg kg(-1) oral dose. The mean target AUC(0,∞) for initial dose titration was 115 mg l(-1)  h. We developed a PK model-based individualized dosing strategy for the prospective Therapeutic Response Evaluation and Adherence Trial (TREAT, ClinicalTrials.gov NCT02286154). This approach has the potential to optimize the dose titration of hydroxyurea therapy for children with SCA, such that the clinical benefits at MTD are achieved more quickly. © 2015 The British Pharmacological Society.

Statistics and assessment of individual dose from occupational exposure in nuclear industry (1985-1990)

International Nuclear Information System (INIS)

Wang Yunfang; Yang Lianzhen

1993-01-01

The summary and main results of individual dose monitoring (1985-1990) from occupational exposure in nuclear industry are presented. The statistical results show that the annual collective dose equivalent from external exposure to workers in six plants and institutes in 1985-1990 are 29.88, 26.95, 19.16, 14.26, 9.08 and 9.22 man · Sv, respectively. The annual average dose equivalent are 4.98, 4.66, 3.65, 2.79, 2.40 and 2,27 mSv, respectively. The general situation for individual dose monitoring from internal exposure is briefly introduced. The internal exposure dose from uranium, plutonium and tritium in some facilities are given. The annual average committed effective dose equivalent are less than 5.0 mSv. The individual dose monitoring results for occupational exposure from uranium mining are depicted. The individual dose monitoring data are analysed preliminarily

Estimation of doses to individuals from radionuclides disposed of in Solid Waste Storage Area 6

International Nuclear Information System (INIS)

Fields, D.E.; Boegly, W.J. Jr.; Huff, D.D.

1986-01-01

A simple methodology has been applied to estimate maximum possible doses to individuals from exposure to radionuclides released from Solid Waste Storage Area No. 6. This is the only operating shallow-land disposal site for radioactive waste at the Oak Ridge National Laboratory. The methodology is based upon simple, conservative assumptions. A data base of radionuclides disposed of in trenches and auger holes was prepared, and several radionuclide transport and ingestion scenarios were considered. The results of these simulations demonstrate the potential for adverse health effects associated with this waste disposal area, and support the need for further calculations using more complete and realistic assumptions

Neutron spectrum and dose-equivalent in shuttle flights during solar maximum

Energy Technology Data Exchange (ETDEWEB)

Keith, J E; Badhwar, G D; Lindstrom, D J [National Aeronautics and Space Administration, Houston, TX (United States). Lyndon B. Johnson Space Center

1992-01-01

This paper presents unambiguous measurements of the spectrum of neutrons found in spacecraft during spaceflight. The neutron spectrum was measured from thermal energies to about 10 MeV using a completely passive system of metal foils as neutron detectors. These foils were exposed to the neutron flux bare, covered by thermal neutron absorbers (Gd) and inside moderators (Bonner spheres). This set of detectors was flown on three U.S. Space Shuttle flights, STS-28, STS-36 and STS-31, during the solar maximum. We show that the measurements of the radioactivity of these foils lead to a differential neutron energy spectrum in all three flights that can be represented by a power law, J(E){approx equal}E{sup -0.765} neutrons cm{sup -2} day {sup -1} MeV{sup -1}. We also show that the measurements are even better represented by a linear combination of the terrestrial neutron albedo and a spectrum of neutrons locally produced in a aluminium by protons, computed by a previous author. We use both approximations to the neutron spectrum to produce a worst case and most probable case for the neutron spectra and the resulting dose-equivalents, computed using ICRP-51 neutron fluence-dose conversion tables. We compare these to the skin dose-equivalents due to charged particles during the same flights. (author).

Benefits of the maximum tolerated dose (MTD) and maximum tolerated concentration (MTC) concept in aquatic toxicology

International Nuclear Information System (INIS)

Hutchinson, Thomas H.; Boegi, Christian; Winter, Matthew J.; Owens, J. Willie

2009-01-01

There is increasing recognition of the need to identify specific sublethal effects of chemicals, such as reproductive toxicity, and specific modes of actions of the chemicals, such as interference with the endocrine system. To achieve these aims requires criteria which provide a basis to interpret study findings so as to separate these specific toxicities and modes of action from not only acute lethality per se but also from severe inanition and malaise that non-specifically compromise reproductive capacity and the response of endocrine endpoints. Mammalian toxicologists have recognized that very high dose levels are sometimes required to elicit both specific adverse effects and present the potential of non-specific 'systemic toxicity'. Mammalian toxicologists have developed the concept of a maximum tolerated dose (MTD) beyond which a specific toxicity or action cannot be attributed to a test substance due to the compromised state of the organism. Ecotoxicologists are now confronted by a similar challenge and must develop an analogous concept of a MTD and the respective criteria. As examples of this conundrum, we note recent developments in efforts to validate protocols for fish reproductive toxicity and endocrine screens (e.g. some chemicals originally selected as 'negatives' elicited decreases in fecundity or changes in endpoints intended to be biomarkers for endocrine modes of action). Unless analogous criteria can be developed, the potentially confounding effects of systemic toxicity may then undermine the reliable assessment of specific reproductive effects or biomarkers such as vitellogenin or spiggin. The same issue confronts other areas of aquatic toxicology (e.g., genotoxicity) and the use of aquatic animals for preclinical assessments of drugs (e.g., use of zebrafish for drug safety assessment). We propose that there are benefits to adopting the concept of an MTD for toxicology and pharmacology studies using fish and other aquatic organisms and the

Individual external monitoring system for gamma and X ray evaluation of the individual dose equivalent 'HP(10)', utilizing a photographic dosimetry technique

International Nuclear Information System (INIS)

Santoro, Christiana; Filho, Joao Antonio

2008-01-01

Full text: Individual monitoring evaluates external sources of ionizing radiation X, γ, β and n, to which workers are occupationally exposed, for ensuring safe and acceptable radiological conditions in their places of employment. The dose received by workers should attend the limits authorized by national regulatory organs. Nowadays, there are two radiometric unit systems, based on resolutions of the National Nuclear Energy Commission (NNEC) and the International Commission on Radiation Units and Measurements (ICRU); in the conventional (NNEC) system, the doses received by workers are evaluated through the individual dose H x , where dosemeters used on surface of thorax are calibrated in terms of air kerma; in the recent system (ICRU), the doses are evaluated through the individual dose equivalent H P (d), where dosemeters are calibrated in terms of dose from phantom. The recent system improves the method of evaluation, by taking into account the scattering effect and absorption of radiation in the human body. This work adapts a photographic dosimetry service to the recent ICRU publications, for evaluation of individual monitoring, in function of the individual dose equivalent H P (10) of strong penetrating radiation. For this, a methodology based on linear programming and determination of calibration curves is used for radiation capacities, wide (W) and narrow (N) spectra, as described by the International Organization for Standardization (ISO 4037-1, 1995). These calibration curves offer better accuracy in the determination of doses and energy, which will improve the quality of the service given to society. The results show that the values of individual dose equivalent, evaluated at intervals of 0.2 to 200 mSv, have lower significant uncertainties (10%) than those recommended by the ICRP 75, for individual monitoring; therefore, the evaluation system for developed doses attends the new recommendations proposed by International Commissions. From what has been

Individualized Neoral doses in pediatric renal transplantation.

Science.gov (United States)

García, Y; Muquillaza, P; Valdebenito, S

2010-01-01

We propose a model to calculate individualized Neoral doses based on individual oral clearance (CL/F)(i) and AUC((0-12h)) values. The equation proposed by Dr. Ke-Hua Wu (2005), was employed to calculate the CL/F(i) = 28,5 - (1.24*POD) - 0.252*(TBil-11) + 0,188*(Weight o-58) -0,191*(Age-42) - 2,42*INHI - 0,212*(HCT-28), where CI/F = (L/h), POD = postoperative days, Bil.T = total bilirubin level (umol/L), CBW = in kilograms, age = in years, INHI = concurrent metabolic inhibitors present (1) or absence (0), and HCT = hematocrit percentage. The AUC((0-12h)) was calculated from the C(2) value using the equation AUC((0-12h)) = 815,578 + 4,44696*C(2), derived from the linear correlation observed in earlier work at Clinica Las Condes Hospital. The studied population were 30 kidney transplanted children at Luis Calvo Mackenna Hospital, between 2002 and 2006, who were divided into 2 similar groups according to accurate C(2) sampling time collections. The control group 1 was composed of 13 patients of age 9.85 +/- 4 years whose samples were collected correctly. Group 2 was composed of 17 patients of age 10.43 +/- 6 years with 252 C(2) samples, which were obtained at medical control. All patients were under oral treatment with prednisone, azathioprine, nifedipine, and Neoral administered twice day according the weight of the patient and the C(2) level. Relating Neoral administered doses to calculated doses according to the proposed model, the control group showed a linear correlation coefficient r = 0.924; r(2) = 85.4%; (P calculate Neoral doses had a predictive value of 85.0% when C(2) samples were collected correctly.

Quantification of individual of individual annual doses to the public due to Embalse NPP operation

International Nuclear Information System (INIS)

Salas, Carlos

2008-01-01

This paper compares the individual annual doses to the public produced during Embalse NPP operation and the natural radiation doses absorbed in everyday life by the same individuals. The basic idea is to show several examples that allow the comparison. Therefore, everybody will get a clear picture of the radiological contamination that surrounds us and the actual influence that Embalse NPP's operation has in the environment. The first concept to be considered is that the human body cells cannot distinguish whether radiation comes from a natural or an artificial source (a source created by man). This is of great importance in the case of the popular myth that says that radiation coming from artificial sources is the only damaging radiation, and that other types of radiation are innocuous, and represent no hazard to human health. We can preliminarily state that when considering the same dose, the effects of both kinds of radiation in human body are equal. (author)

A preliminary study to find out maximum occlusal bite force in Indian individuals

DEFF Research Database (Denmark)

Jain, Veena; Mathur, Vijay Prakash; Pillai, Rajath

2014-01-01

PURPOSE: This preliminary hospital based study was designed to measure the mean maximum bite force (MMBF) in healthy Indian individuals. An attempt was made to correlate MMBF with body mass index (BMI) and some of the anthropometric features. METHODOLOGY: A total of 358 healthy subjects in the ag...

Estimation of population dose from all sources in Japan

International Nuclear Information System (INIS)

Kusama, Tomoko; Nakagawa, Takeo; Kai, Michiaki; Yoshizawa, Yasuo

1988-01-01

The purposes of estimation of population doses are to understand the per-caput doses of the public member from each artificial radiation source and to determine the proportion contributed of the doses from each individual source to the total irradiated population. We divided the population doses into two categories: individual-related and source-related population doses. The individual-related population dose is estimated based on the maximum assumption for use in allocation of the dose limits for members of the public. The source-related population dose is estimated both to justify the sources and practices and to optimize radiation protection. The source-related population dose, therefore, should be estimated as realistically as possible. We investigated all sources that caused exposure to the population in Japan from the above points of view

X-rays individual dose assessment using TLD dosimeters

International Nuclear Information System (INIS)

Salas, Carlos

2008-01-01

This paper describes the methodology used in Embalse NPP for measuring individual X-ray dose in dentists and radiologists, who work in areas near the plant. Personnel is provided with TLD personal dosimeters for thoracic use, as well as TLD ring dosimeters. This individual X-ray dosimetry is fundamental in order to know the effective energy coming from the radiation field, since the dosimetry factors depend on it. On the other hand, the response of the TLD crystals also depends of the effective energy; this accentuates the problem when assessing the individual dose. The X-ray dosimeter must simultaneously determine the value of the effective energy and the corresponding dose value. The basic principle for determining effective energy is by using at least two different TLD materials covered by filters of different thickness. The TLD materials used have totally energy responses. Therefore, different readouts from each of the crystals are obtained. The ratio between both readouts provides a factor that depends of the effective energy but that is 'independent' from the exposure values irradiated to the dosimeter. The Personal TLD dosimeter currently in use is Bicron-Harshaw. It comprises a carrier model 8807. This carrier contains a card model 2211 which groups two TLD 200 crystals and two TLD 100 crystals. It has internal filters at each side of the TLD 200 crystals. The periodical calibration of these dosimeters consists in the irradiation of some dosimeters with different X-ray energy beams in the National Atomic Energy Commission (CNEA). This dosimeter was used, by the National Regulatory Authority (ARN) in several comparisons, always getting satisfactory results. (author)

Dose record keeping: a multi purpose tool in individual monitoring

International Nuclear Information System (INIS)

Bermann, F.; Julius, H.W.

1993-01-01

Proper recording of radiation doses is an essential part of the process of individual monitoring and shares in the same objective. A dose record keeping system is more than just a computer based data storage system and should rather be a Dose Registration and Information System (DRIS). Objectives of dose record keeping are given. As a result of the integration of member states of the European Communities, co-operation and exchange of personnel between countries will be increasing. This will probably require national dose registration systems and adequate data communication between them. These developments emphasize the necessity for international harmonization of dose record keeping systems and categorization of the data they contain. General characteristics and specific aspects of dose record keeping systems will be dealt with. Attention will also be given to some special applications of the recorded information, such as: the use of data for epidemiological studies and for QA purposes. (authors). 5 tabs., 4 refs

Influence on the individual dose by using lead aprons at hemodynamic services

International Nuclear Information System (INIS)

Alonso, Thessa Cristina; Silva, Teogenes Augusto da

2005-01-01

In interventional radiology, heart catheterism procedures are done with therapeutic and diagnosis purposes. In those medical practices, staff members are required to wear lead aprons for individual protection beside other protective equipment like thyroid lead protector, lead eyeglasses and gloves. The proper and suitable equipment is chosen according to the exam type. Exposure of medical team is under discussion concerned to use of the individual dosimeter under or on the lead apron and the need to apply a dose correction factor of 0.01 in the first case to estimate the effective dose. This work investigates personal doses of medical team in interventional radiology services of two hospitals in Belo Horizonte. Individual thermoluminescent dosimeters were fastened under and on lead aprons during one month period to measure the personal dose equivalents, Hp(10). Results indicate that the dose correction factor due to the lead apron presence is not a proper correction for interventional radiology exams; different factors are suggested if the worker is closer or not so close the x-ray beam. Additionally, it is emphasized that the use of adequate protective aprons and conscientious behavior according to a safety culture can minimize the radiation exposure of those professionals. (author)

Individual doses' register of occupationally exposed persons in the Republic of Moldova

International Nuclear Information System (INIS)

Hustuc, A.; Chiruta, Iu.

2009-01-01

The storage and processing of the data acquired through different monitoring techniques are of vital importance for controlling the individual doses of the occupationally exposed workers facilitating the determination of exposure pathway and furthering the policy of radiological protection. The use of the data bases for the evidence of the individual doses of the occupationally exposed workers to the ionizing radiation is useful in studies of risks and potential exposure, and in future epidemiological studies. (authors)

Individual Dose Calculations with Use of the Revised Techa River Dosimetry System TRDS-2009D

Energy Technology Data Exchange (ETDEWEB)

Degteva, M. O.; Shagina, N. B.; Tolstykh, E. I.; Vorobiova, M. I.; Anspaugh, L. R.; Napier, Bruce A.

2009-10-23

An updated deterministic version of the Techa River Dosimetry System (TRDS-2009D) has been developed to estimate individual doses from external exposure and intake of radionuclides for residents living on the Techa River contaminated as a result of radioactive releases from the Mayak plutonium facility in 1949–1956. The TRDS-2009D is designed as a flexible system that uses, depending on the input data for an individual, various elements of system databases to provide the dosimetric variables requested by the user. Several phases are included in the computation schedule. The first phase includes calculations with use of a common protocol for all cohort members based on village-average-intake functions and external dose rates; individual data on age, gender and history of residence are included in the first phase. This phase results in dose estimates similar to those obtained with system TRDS-2000 used previously to derive risks of health effects in the Techa River Cohort. The second phase includes refinement of individual internal doses for those persons who have had body-burden measurements or exposure parameters specific to the household where he/she lived on the Techa River. The third phase includes summation of individual doses from environmental exposure and from radiological examinations. The results of TRDS-2009D dose calculations have demonstrated for the ETRC members on average a moderate increase in RBM dose estimates (34%) and a minor increase (5%) in estimates of stomach dose. The calculations for the members of the ETROC indicated similar small changes for stomach, but significant increase in RBM doses (400%). Individual-dose assessments performed with use of TRDS-2009D have been provided to epidemiologists for exploratory risk analysis in the ETRC and ETROC. These data provide an opportunity to evaluate the possible impact on radiogenic risk of such factors as confounding exposure (environmental and medical), changes in the Techa River source

Regulatory Forum Opinion Piece*: Retrospective Evaluation of Doses in the 26-week Tg.rasH2 Mice Carcinogenicity Studies: Recommendation to Eliminate High Doses at Maximum Tolerated Dose (MTD) in Future Studies.

Science.gov (United States)

Paranjpe, Madhav G; Denton, Melissa D; Vidmar, Tom J; Elbekai, Reem H

2015-07-01

High doses in Tg.rasH2 carcinogenicity studies are usually set at the maximum tolerated dose (MTD), although this dose selection strategy has not been critically evaluated. We analyzed the body weight gains (BWGs), mortality, and tumor response in control and treated groups of 29 Tg.rasH2 studies conducted at BioReliance. Based on our analysis, it is evident that the MTD was exceeded at the high and/or mid-doses in several studies. The incidence of tumors in high doses was lower when compared to the low and mid-doses of both sexes. Thus, we recommend that the high dose in male mice should not exceed one-half of the estimated MTD (EMTD), as it is currently chosen, and the next dose should be one-fourth of the EMTD. Because females were less sensitive to decrements in BWG, the high dose in female mice should not exceed two-third of EMTD and the next dose group should be one-third of EMTD. If needed, a third dose group should be set at one-eighth EMTD in males and one-sixth EMTD in females. In addition, for compounds that do not show toxicity in the range finding studies, a limit dose should be applied for the 26-week carcinogenicity studies. © 2014 by The Author(s).

Maximum likelihood estimation of dose-response parameters for therapeutic operating characteristic (TOC) analysis of carcinoma of the nasopharynx

International Nuclear Information System (INIS)

Metz, C.E.; Tokars, R.P.; Kronman, H.B.; Griem, M.L.

1982-01-01

A Therapeutic Operating Characteristic (TOC) curve for radiation therapy plots, for all possible treatment doses, the probability of tumor ablation as a function of the probability of radiation-induced complication. Application of this analysis to actual therapeutic situation requires that dose-response curves for ablation and for complication be estimated from clinical data. We describe an approach in which ''maximum likelihood estimates'' of these dose-response curves are made, and we apply this approach to data collected on responses to radiotherapy for carcinoma of the nasopharynx. TOC curves constructed from the estimated dose-response curves are subject to moderately large uncertainties because of the limitations of available data.These TOC curves suggest, however, that treatment doses greater than 1800 rem may substantially increase the probability of tumor ablation with little increase in the risk of radiation-induced cervical myelopathy, especially for T1 and T2 tumors

Skin dose estimation due to a contamination by a radionuclide β emitter: are doses equivalent good estimator of protection quantities?

International Nuclear Information System (INIS)

Bourgois, L.

2011-01-01

When handling radioactive β emitters, measurements in terms of personal dose equivalents H p (0.07) are used to estimate the equivalent dose limit to skin or extremities given by regulations. First of all, analytical expressions for individual dose equivalents H p (0.07) and equivalent doses to the extremities H skin are given for a point source and for contamination with a radionuclide β emitter. Second of all, operational quantities and protection quantities are compared. It is shown that in this case the operational quantities significantly overstate the protection quantities. For a skin contamination the ratio between operational quantities and protection quantities is 2 for a maximum β energy of 3 MeV and 90 for a maximum β energy of 150 keV. (author)

Collective dose, conceptual basis and practical applications

International Nuclear Information System (INIS)

Bonka, H.

1985-01-01

In the ICRP Publications no. 22(1973) and no. 26(1977), the ICRP recommends that the maximum permissible whole-body dose by kept below the dose limits corresponding to the sum of all effective dose equivalents of the persons concerned, i.e. the collective dose. The effective dose equivalent is recommended by the ICRP for use as a new quantity for evaluating the stochastic radiation dose for individual persons. Examples are given by the author explaining cost-benefit analyses according to ICRP recommendations, especially discussing the definition of optimum local dose limits with regard to shielding design in nuclear installations. (DG) [de

Correlation of patient maximum skin doses in cardiac procedures with various dose indicators

International Nuclear Information System (INIS)

Domienik, J.; Papierz, S.; Jankowski, J.; Peruga, J.Z.; Werduch, A.; Religa, W.

2008-01-01

In most countries of European Union, legislation requires the determination of the total skin dose received by patients during interventional procedures in order to prevent deterministic damages. Various dose indicators like dose-area product (DAP), cumulative dose (CD) and entrance dose at the patient plane (EFD) are used for patient dosimetry purposes in clinical practice. This study aimed at relating those dose indicators with doses ascribed to the most irradiated areas of the patient skin usually expressed in terms of local maximal skin dose (MSD). The study was performed in two different facilities for two most common cardiac procedures coronary angiography (CA) and percutaneous coronary interventions (PCI). For CA procedures, the registered values of fluoroscopy time, total DAP and MSD were in the range (0.7-27.3) min, (16-317) Gy cm 2 and (43-1507) mGy, respectively, and for interventions, accordingly (2.1-43.6) min, (17-425) Gy cm 2 , (71-1555) mGy. Moreover, for CA procedures, CD and EFD were in the ranges (295-4689) mGy and (121-1768) mGy and for PCI (267-6524) mGy and (68-2279) mGy, respectively. No general and satisfactory correlation was found for safe estimation of MSD. However, results show that the best dose indicator which might serve for rough, preliminary estimation is DAP value. In the study, the appropriate trigger levels were proposed for both facilities. (authors)

User Instructions for the CiderF Individual Dose Code and Associated Utility Codes

Energy Technology Data Exchange (ETDEWEB)

Eslinger, Paul W.; Napier, Bruce A.

2013-08-30

Historical activities at facilities producing nuclear materials for weapons released radioactivity into the air and water. Past studies in the United States have evaluated the release, atmospheric transport and environmental accumulation of 131I from the nuclear facilities at Hanford in Washington State and the resulting dose to members of the public (Farris et al. 1994). A multi-year dose reconstruction effort (Mokrov et al. 2004) is also being conducted to produce representative dose estimates for members of the public living near Mayak, Russia, from atmospheric releases of 131I at the facilities of the Mayak Production Association. The approach to calculating individual doses to members of the public from historical releases of airborne 131I has the following general steps: • Construct estimates of releases 131I to the air from production facilities. • Model the transport of 131I in the air and subsequent deposition on the ground and vegetation. • Model the accumulation of 131I in soil, water and food products (environmental media). • Calculate the dose for an individual by matching the appropriate lifestyle and consumption data for the individual to the concentrations of 131I in environmental media at their residence location. A number of computer codes were developed to facilitate the study of airborne 131I emissions at Hanford. The RATCHET code modeled movement of 131I in the atmosphere (Ramsdell Jr. et al. 1994). The DECARTES code modeled accumulation of 131I in environmental media (Miley et al. 1994). The CIDER computer code estimated annual doses to individuals (Eslinger et al. 1994) using the equations and parameters specific to Hanford (Snyder et al. 1994). Several of the computer codes developed to model 131I releases from Hanford are general enough to be used for other facilities. This document provides user instructions for computer codes calculating doses to members of the public from atmospheric 131I that have two major differences from the

WAYS TO INCREASE ACCURACY AND RELIABILITY OF INDIVIDUAL DOSES ASSESSMENTS IN PERSONNEL WITHIN THERMOLUMINESCENCE TECHNIQUE

Directory of Open Access Journals (Sweden)

G. N. Kaydanovskiy

2012-01-01

Full Text Available The paper analyses the main sources of measurement errors of individual doses in personnel performed within the thermoluminescence technique and gives recommendations to minimize these errors. The reasons that reduce reliability of effective dose assessments derived from measured values of personal dose equivalent are imperfections of guidance documents. Changes to the Guidelines «Organization and implementation of individual dosimetric control. Staff of health institutions» are justified.

Effects of Minimum and Maximum Doses of Furosemide on Fractional Shortening Parameter in Echocardiography of the New Zealand White Rabbit

Directory of Open Access Journals (Sweden)

Roham Vali, Mohammad Nasrollahzadeh Masouleh* and Siamak Mashhady Rafie1

2013-04-01

Full Text Available There is no data on the effect of maximum and minimum doses of furosemide on heart's work performance and amount of fractional shortening (FS in echocardiography of rabbit. This study was designed to validate probability of the mentionable effect. Twenty-four healthy female New Zealand white rabbits were divided into four equal groups. Maximum and minimum doses of furosemide were used for the first and second groups and the injection solution for the third and fourth groups was sodium chloride 0.9% which had the same calculated volumes of furosemide for the first two groups, respectively. The left ventricle FS in statutory times (0, 2, 5, 15, 30 minutes was determined by echocardiography. Measurements of Mean±SD, maximum and minimum amounts for FS values in all groups before injection and in statutory times were calculated. Statistical analysis revealed non-significant correlation between the means of FS. The results of this study showed that furosemide can be used as a diuretic agent for preparing a window approach in abdominal ultrasonography examination with no harmful effect on cardiac function.

Uncertainties in individual doses in a case-control study of thyroid cancer after the Chernobyl accident

International Nuclear Information System (INIS)

Drozdovitch, V.; Maceika, E.; Khrouch, V.; Zvonova, I.; Vlasov, O.; Bouville, A.; Cardis, E.

2007-01-01

Individual radiation doses to the thyroid were reconstructed for 2239 subjects of a case-control study of thyroid cancer among young people that was carried out in regions of Belarus and Russia contaminated by radioactive fallout from the Chernobyl accident. Although the process of dose reconstruction provides a point estimate of each subject's dose, it is obvious that there is uncertainty associated with these dose calculations. The following main sources of uncertainty in the estimated individual doses were identified: (1) shared and un-shared errors associated with parameters of the dosimetry model; and (2) un-shared errors that are associated with the variability, reliability and ability of information from the personal interviews. Besides setting up proper distributions for the parameters of the dosimetry model, inter-individual correlations were also defined to take into account shared errors. By the application of Monte Carlo simulations, a set of approximately log-normally distributed thyroid doses was obtained for each subject; the geometric standard deviations of the distributions are found to vary among individuals from 1.7 to 3.7. (authors)

Effects of different strength training frequencies on maximum strength, body composition and functional capacity in healthy older individuals.

Science.gov (United States)

Turpela, Mari; Häkkinen, Keijo; Haff, Guy Gregory; Walker, Simon

2017-11-01

There is controversy in the literature regarding the dose-response relationship of strength training in healthy older participants. The present study determined training frequency effects on maximum strength, muscle mass and functional capacity over 6months following an initial 3-month preparatory strength training period. One-hundred and six 64-75year old volunteers were randomly assigned to one of four groups; performing strength training one (EX1), two (EX2), or three (EX3) times per week and a non-training control (CON) group. Whole-body strength training was performed using 2-5 sets and 4-12 repetitions per exercise and 7-9 exercises per session. Before and after the intervention, maximum dynamic leg press (1-RM) and isometric knee extensor and plantarflexor strength, body composition and quadriceps cross-sectional area, as well as functional capacity (maximum 7.5m forward and backward walking speed, timed-up-and-go test, loaded 10-stair climb test) were measured. All experimental groups increased leg press 1-RM more than CON (EX1: 3±8%, EX2: 6±6%, EX3: 10±8%, CON: -3±6%, Ptraining frequency would induce greater benefit to maximum walking speed (i.e. functional capacity) despite a clear dose-response in dynamic 1-RM strength, at least when predominantly using machine weight-training. It appears that beneficial functional capacity improvements can be achieved through low frequency training (i.e. 1-2 times per week) in previously untrained healthy older participants. Copyright © 2017 Elsevier Inc. All rights reserved.

Estimate of absorbed dose received by individuals irradiated with neutrons

International Nuclear Information System (INIS)

Fonseca, E.S. da; Mauricio, C.L.P.

1995-01-01

An innovating methodology is proposed to estimate the absorbed dose received by individuals irradiated with neutrons in an accident, even in the case that the victim is not using any kind of neutron dosemeter. The method combines direct measurements of 24 Na and 32 P activated in the human body. The calculation method was developed using data taken from previously published papers and experimental measurements. Other irradiations results in different neutron spectra prove the validity of the methodology here proposed. Using a whole body counter to measure 24 Na activity, it is possible to evaluate neutron absorbed doses in the order of 140 μGy of very soft (thermal) spectra. For fast neutron fields, the lower limit for neutron dose detection increases, but the present method continues to be very useful in accidents, with higher neutron doses. (author). 5 refs., 1 fig., 4 tabs

The ICRP Proposed Maximum Public Dose Constraints of o.3 mSv/y: a Major Issue for the Nuclear Industry

International Nuclear Information System (INIS)

Saint-Pierre, S.; Coates, R.

2004-01-01

The International Commission on Radiological Protection (ICRP) is currently developing a new set of Recommendations on Radiological Protection. A value of 0.3mSv/y for the maximum public dose constraint has been discussed by ICRP. This value represents a major concern for the nuclear industry at large. The primary issue arises from the lack of any new scientific evidence on public health effects from ionising radiation to support, in practice, the proposed reduction by about a factor of 3 (from 1 to 0.3 mSv/y) of the upper bound value for public dose impact from a nuclear activity or site. Such a change would create a de facto limit on public exposure from specific sources at a dose level of about one tenth of average natural background and an even smaller fraction of the typical range of background exposures and exposures from medical sources. This cannot be justified on public health grounds. The WNA supports ICRP's renewed intention, as expressed at the NEA-ICRP Stakeholder Forum in Lanzarote (April 2003), to retain the concept of a public dose limit at 1 mSv/y. We strongly believe that the current system comprising of the dose limit and the ALARA Principle provides the necessary flexibility and tools for regulators to address all situations in all countries. The WNA consider that the question of setting an upper bound dose constraint (below 1 mSv/y) at the country/site specific level is best left for discussion and agreement between the local stakeholders rather than at an international level. When considering the potential practical implications of a maximum dose constraint, it is important to look beyond the very low off-site dose impacts (on the public) resulting from annual routine radioactive discharges of nuclear industrial sites. There are many off-site and on-site practical situations, related to public exposures (both workers and the public) and worker classification as well as activities such transportation, decommissioning and site remediation, for

The ICRP Proposed Maximum Public Dose Constraints of o.3 mSv/y: a Major Issue for the Nuclear Industry

Energy Technology Data Exchange (ETDEWEB)

Saint-Pierre, S.; Coates, R.

2004-07-01

The International Commission on Radiological Protection (ICRP) is currently developing a new set of Recommendations on Radiological Protection. A value of 0.3mSv/y for the maximum public dose constraint has been discussed by ICRP. This value represents a major concern for the nuclear industry at large. The primary issue arises from the lack of any new scientific evidence on public health effects from ionising radiation to support, in practice, the proposed reduction by about a factor of 3 (from 1 to 0.3 mSv/y) of the upper bound value for public dose impact from a nuclear activity or site. Such a change would create a de facto limit on public exposure from specific sources at a dose level of about one tenth of average natural background and an even smaller fraction of the typical range of background exposures and exposures from medical sources. This cannot be justified on public health grounds. The WNA supports ICRP's renewed intention, as expressed at the NEA-ICRP Stakeholder Forum in Lanzarote (April 2003), to retain the concept of a public dose limit at 1 mSv/y. We strongly believe that the current system comprising of the dose limit and the ALARA Principle provides the necessary flexibility and tools for regulators to address all situations in all countries. The WNA consider that the question of setting an upper bound dose constraint (below 1 mSv/y) at the country/site specific level is best left for discussion and agreement between the local stakeholders rather than at an international level. When considering the potential practical implications of a maximum dose constraint, it is important to look beyond the very low off-site dose impacts (on the public) resulting from annual routine radioactive discharges of nuclear industrial sites. There are many off-site and on-site practical situations, related to public exposures (both workers and the public) and worker classification as well as activities such transportation, decommissioning and site remediation

SU-F-J-59: Assessment of Dose Response Distribution in Individual Human Tumor

Energy Technology Data Exchange (ETDEWEB)

Yan, D [William Beaumont Hospital, Royal Oak, MI (United States); Chen, S; Krauss, D; Chen, P [Beaumont Health System, Royal Oak, Michigan (United States); Wilson, G [Beaumont Health System, Royal Oak, MI (United States)

2016-06-15

Purpose: To fulfill precision radiotherapy via adaptive dose painting by number, voxel-by-voxel dose response or radio-sensitivity in individual human tumor needs to be determined in early treatment to guide treatment adaptation. In this study, multiple FDG PET images obtained pre- and weekly during the treatment course were utilized to determine the distribution/spectrum of dose response parameters in individual human tumors. Methods: FDG PET/CT images of 18 HN cancer patients were used in the study. Spatial parametric image of tumor metabolic ratio (dSUV) was created following voxel by voxel deformable image registration. Each voxel value in dSUV was a function of pre-treatment baseline SUV and treatment delivered dose, and used as a surrogate of tumor survival fraction (SF). Regression fitting with break points was performed using the LQ-model with tumor proliferation for the control and failure group of tumors separately. The distribution and spectrum of radiation sensitivity and growth in individual tumors were determined and evaluated. Results: Spectrum of tumor dose-sensitivity and proliferation in the controlled group was broad with α in tumor survival LQ-model from 0.17 to 0.8. It was proportional to the baseline SUV. Tlag was about 21∼25 days, and Tpot about 0.56∼1.67 days respectively. Commonly tumor voxels with high radio-sensitivity or larger α had small Tlag and Tpot. For the failure group, the radio-sensitivity α was low within 0.05 to 0.3, but did not show clear Tlag. In addition, tumor voxel radio-sensitivity could be estimated during the early treatment weeks. Conclusion: Dose response distribution with respect to radio-sensitivity and growth in individual human tumor can be determined using FDG PET imaging based tumor metabolic ratio measured in early treatment course. The discover is critical and provides a potential quantitative objective to implement tumor specific precision radiotherapy via adaptive dose painting by number.

MAXIMUM NUMBER OF REPETITIONS, TOTAL WEIGHT LIFTED AND NEUROMUSCULAR FATIGUE IN INDIVIDUALS WITH DIFFERENT TRAINING BACKGROUNDS

Directory of Open Access Journals (Sweden)

Valeria Panissa

2013-04-01

Full Text Available The aim of this study was to evaluate the performance, as well as neuromuscular activity, in a strength task in subjects with different training backgrounds. Participants (n = 26 were divided into three groups according to their training backgrounds (aerobic, strength or mixed and submitted to three sessions: (1 determination of the maximum oxygen uptake during the incremental treadmill test to exhaustion and familiarization of the evaluation of maximum strength (1RM for the half squat; (2 1RM determination; and (3 strength exercise, four sets at 80�0of the 1RM, in which the maximum number of repetitions (MNR, the total weight lifted (TWL, the root mean square (RMS and median frequency (MF of the electromyographic (EMG activity for the second and last repetition were computed. There was an effect of group for MNR, with the aerobic group performing a higher MNR compared to the strength group (P = 0.045, and an effect on MF with a higher value in the second repetition than in the last repetition (P = 0.016. These results demonstrated that individuals with better aerobic fitness were more fatigue resistant than strength trained individuals. The absence of differences in EMG signals indicates that individuals with different training backgrounds have a similar pattern of motor unit recruitment during a resistance exercise performed until failure, and that the greater capacity to perform the MNR probably can be explained by peripheral adaptations.

Regulatory Forum Opinion Piece*: Retrospective Evaluation of Doses in the 26-week Tg.rasH2 Mice Carcinogenicity Studies: Recommendation to Eliminate High Doses at Maximum Tolerated Dose in Future Studies. A Response to the Counterpoints.

Science.gov (United States)

Paranjpe, Madhav G; Denton, Melissa D; Vidmar, Tom J; Elbekai, Reem H

2016-01-01

We recently conducted a retrospective analysis of data collected from 29 Tg.rasH2 carcinogenicity studies conducted at our facility to determine how successful was the strategy of choosing the high dose of the 26-week studies based on an estimated maximum tolerated dose (MTD). As a result of our publication, 2 counterviews were expressed. Both counterviews illustrate very valid points in their interpretation of our data. In this article, we would like to highlight clarifications based on several points and issues they have raised in their papers, namely, the dose-level selection, determining if MTD was exceeded in 26-week studies, and a discussion on the number of dose groups to be used in the studies. © The Author(s) 2015.

HADOC: a computer code for calculation of external and inhalation doses from acute radionuclide releases

International Nuclear Information System (INIS)

Strenge, D.L.; Peloquin, R.A.

1981-04-01

The computer code HADOC (Hanford Acute Dose Calculations) is described and instructions for its use are presented. The code calculates external dose from air submersion and inhalation doses following acute radionuclide releases. Atmospheric dispersion is calculated using the Hanford model with options to determine maximum conditions. Building wake effects and terrain variation may also be considered. Doses are calculated using dose conversion factor supplied in a data library. Doses are reported for one and fifty year dose commitment periods for the maximum individual and the regional population (within 50 miles). The fractional contribution to dose by radionuclide and exposure mode are also printed if requested

Concept and approaches used in assessing individual and collective doses from releases of radioactive effluents

International Nuclear Information System (INIS)

1988-06-01

To guide on the applications of the principles for limiting radioactive releases contained in Safety Series 77, the Agency is in the process of preparing a number of safety guides. The first one is this present document which deals with the principal aspects of the methods for the assessment of the individual and collective dose. It aims at giving a general guidance to those responsible for establishing programmes for the determination of individual doses as well as collective doses in connection with licensing a site for a nuclear installation. The document is concerned with the principles applied for calculating individual and collective doses from routine releases of radionuclides to the atmosphere and hydrosphere but not releases directly to the geosphere, as in waste management. These areas will be covered by other Agency publications. 75 refs, figs and tabs

Individual and collective doses associated with the transport of irradiated magnox fuel within the UK

International Nuclear Information System (INIS)

Macdonald, H.F.; Mairs, J.H.

1978-12-01

A method is described of evaluating the individual and collective doses arising during the transport of irradiated fuel from a system of nuclear power stations to a central reprocessing plant. The doses associated with irradiated Magnox fuel movements in the UK are estimated and compared with those resulting from other phases of the nuclear fuel cycle. In addition, the individual and collective doses implied by the accidental activity release limits contained within the 1973 IAEA Tranport Regulations are discussed. (author)

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

International Nuclear Information System (INIS)

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

1993-01-01

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

Estimation of individual doses from external exposures and dose-group classification of cohort members in high background radiation area in Yangjiang, China

International Nuclear Information System (INIS)

Yuan Yongling; Shen Hong; Sun Quanfu; Wei Luxin

1999-01-01

Objective: In order to estimate annual effective doses from external exposures in the high background radiation area (HBRA) and in the control area (CA) , the authors measured absorbed dose rates in air from terrestrial gamma radiation with different dosimeters. A dose group classification was an important step for analyzing the dose effects relationship among the cohort members in the investigated areas. The authors used the hamlet specific average annual effective doses of all the 526 hamlets in the investigated areas. A classification of four dose groups was made for the cohort members (high, moderate, low and control) . Methods: For the purpose of studying the dose effect relationships among the cohort members in HBRA and CA, it would be ideal that each subject has his own record of individual accumulated doses received before the evaluation. However, rt is difficult to realize it in practice (each of 106517 persons should wear TLD for a long time) . Thus the authors planned two sets of measurements. Firstly, to measure the environmental dose rates (outdoor, indoor, over the bed) in every hamlet of the investigated area (526 hamlets) , considering the occupancy factors for males and females of different age groups to convert to the annual effective dose from the data of dose rates. Secondly, to measure the individual cumulative dose with TLD for part of the subjects in the investigated areas. Results: Based on the two sets of measurements, the estimates of average annual effective doses in HBRA were 211.86 and 206.75 x 10 -5 Sv/a, respectively, 68.60 and 67.11 x 10 -5 Sv/a, respectively(gamma radiation only) . The intercomparison between these two sets of measurement showed that they were in good correlation. Thus the authors are able to yield the equations of linear regression: Y = 0.9937 + 6.0444, r = 0.9949. Conclusions: The authors took the value obtained from direct measurement as 'standard' , and 15 % for uncertainty of measurement. Since the estimates of

Ingestion dosimetry for assessment of individual dose to the population in HBRA

International Nuclear Information System (INIS)

Jojo, P.J.; Pereira, Christa E.; Chaougaonkar, M.P.

2012-05-01

Epidemiological studies on the population residing in the HBRA in Kerala is of considerable interest from the point of view of understanding the effects of low and chronic radiation exposures on the health of human population. The scope of these studies includes the simultaneous and time integrated measurements of both inhalation dose and external gamma dose due to environmental radiation, which are useful in the analysis of epidemiological studies. While the doses due to external gamma radiation and inhalation can be measured with a reasonable accuracy for an individual, measurement of ingestion dose for the same is quite difficult. In this research project, the radioactivity contents of the food items most commonly used by the population in the region is analysed and then the ingestion dose is estimated using standardized methodologies. (author)

Effects of low dose irradiation on NK activity of normal individuals and patients with cancer

International Nuclear Information System (INIS)

Tian Hailin; Su Liaoyuan

1994-10-01

Effects of low dose irradiation on NK activity of lymphocytes and on K 562 cells were studied. The NK activity was determined by means of 3 H-TdR release assay. While 3 H-TdR incorporation was used to reflect functional changes of K 562 cells after low dose irradiation. 21 patients with cancer and 10 normal individuals were detected. The results indicated that the NK activity of lymphocytes in normal individuals increased significantly after 10 and 50 cGy γ-ray irradiation, while in patients with cancer the NK activity of lymphocytes increased only at the dose of 50 cGy irradiation. The increase of NK activity in normal individuals was higher than that in patients with cancer after same doses of irradiation. When K 562 cells were irradiated by 10 cGy γ-rays, the 3 H-TdR incorporation value increased. After exposed to over 50 cGy the stimulating effect disappeared

Individually dosed omalizumab: an effective treatment for severe peanut allergy.

Science.gov (United States)

Brandström, J; Vetander, M; Lilja, G; Johansson, S G O; Sundqvist, A-C; Kalm, F; Nilsson, C; Nopp, A

2017-04-01

Treatment with omalizumab has shown a positive effect on food allergies, but no dosages are established. Basophil allergen threshold sensitivity (CD-sens) can be used to objectively measure omalizumab treatment efficacy and correlates with the outcome of double-blind placebo-controlled food challenge to peanut. To evaluate whether individualized omalizumab treatment monitored by CD-sens could be an effective intervention for suppression of allergic reactions to peanut. Severely peanut allergic adolescents (n = 23) were treated with omalizumab for 8 weeks, and CD-sens was analysed before and after. Based on whether CD-sens was suppressed after 8 weeks, the patients either were subject to a peanut challenge or received eight more weeks with increased dose of omalizumab, followed by peanut challenge or another 8-week cycle of omalizumab. IgE and IgE-antibodies to peanut and its components were analysed before treatment. After individualized omalizumab treatment (8-24 weeks), all patients continued with an open peanut challenge with no (n = 18) or mild (n = 5) objective allergic symptoms. Patients (n = 15) needing an elevated omalizumab dose (ED) to suppress CD-sens had significantly higher CD-sens values at baseline 1.49 (0.44-20.5) compared to those (n = 8) who managed with normal dose (ND) 0.32 (0.24-5.5) (P omalizumab, monitored by CD-sens, is an effective and safe treatment for severe peanut allergy. The ratio of IgE-ab to storage protein Ara h 2/IgE as well as CD-sens to peanut may predict the need of a higher omalizumab dose. Clinical trials numbers: EudraCT; 2012-005625-78, ClinicalTrials.gov; NCT02402231. © 2016 John Wiley & Sons Ltd.

40 CFR 130.7 - Total maximum daily loads (TMDL) and individual water quality-based effluent limitations.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Total maximum daily loads (TMDL) and individual water quality-based effluent limitations. 130.7 Section 130.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS WATER QUALITY PLANNING AND MANAGEMENT § 130.7 Total...

Main clinical, therapeutic and technical factors related to patient's maximum skin dose in interventional cardiology procedures

Science.gov (United States)

Journy, N; Sinno-Tellier, S; Maccia, C; Le Tertre, A; Pirard, P; Pagès, P; Eilstein, D; Donadieu, J; Bar, O

2012-01-01

Objective The study aimed to characterise the factors related to the X-ray dose delivered to the patient's skin during interventional cardiology procedures. Methods We studied 177 coronary angiographies (CAs) and/or percutaneous transluminal coronary angioplasties (PTCAs) carried out in a French clinic on the same radiography table. The clinical and therapeutic characteristics, and the technical parameters of the procedures, were collected. The dose area product (DAP) and the maximum skin dose (MSD) were measured by an ionisation chamber (Diamentor; Philips, Amsterdam, The Netherlands) and radiosensitive film (Gafchromic; International Specialty Products Advanced Materials Group, Wayne, NJ). Multivariate analyses were used to assess the effects of the factors of interest on dose. Results The mean MSD and DAP were respectively 389 mGy and 65 Gy cm−2 for CAs, and 916 mGy and 69 Gy cm−2 for PTCAs. For 8% of the procedures, the MSD exceeded 2 Gy. Although a linear relationship between the MSD and the DAP was observed for CAs (r=0.93), a simple extrapolation of such a model to PTCAs would lead to an inadequate assessment of the risk, especially for the highest dose values. For PTCAs, the body mass index, the therapeutic complexity, the fluoroscopy time and the number of cine frames were independent explanatory factors of the MSD, whoever the practitioner was. Moreover, the effect of technical factors such as collimation, cinematography settings and X-ray tube orientations on the DAP was shown. Conclusion Optimising the technical options for interventional procedures and training staff on radiation protection might notably reduce the dose and ultimately avoid patient skin lesions. PMID:22457404

Comparison of measured and estimated maximum skin doses during CT fluoroscopy lung biopsies

Energy Technology Data Exchange (ETDEWEB)

Zanca, F., E-mail: Federica.Zanca@med.kuleuven.be [Department of Radiology, Leuven University Center of Medical Physics in Radiology, UZ Leuven, Herestraat 49, 3000 Leuven, Belgium and Imaging and Pathology Department, UZ Leuven, Herestraat 49, Box 7003 3000 Leuven (Belgium); Jacobs, A. [Department of Radiology, Leuven University Center of Medical Physics in Radiology, UZ Leuven, Herestraat 49, 3000 Leuven (Belgium); Crijns, W. [Department of Radiotherapy, UZ Leuven, Herestraat 49, 3000 Leuven (Belgium); De Wever, W. [Imaging and Pathology Department, UZ Leuven, Herestraat 49, Box 7003 3000 Leuven, Belgium and Department of Radiology, UZ Leuven, Herestraat 49, 3000 Leuven (Belgium)

2014-07-15

Purpose: To measure patient-specific maximum skin dose (MSD) associated with CT fluoroscopy (CTF) lung biopsies and to compare measured MSD with the MSD estimated from phantom measurements, as well as with the CTDIvol of patient examinations. Methods: Data from 50 patients with lung lesions who underwent a CT fluoroscopy-guided biopsy were collected. The CT protocol consisted of a low-kilovoltage (80 kV) protocol used in combination with an algorithm for dose reduction to the radiology staff during the interventional procedure, HandCare (HC). MSD was assessed during each intervention using EBT2 gafchromic films positioned on patient skin. Lesion size, position, total fluoroscopy time, and patient-effective diameter were registered for each patient. Dose rates were also estimated at the surface of a normal-size anthropomorphic thorax phantom using a 10 cm pencil ionization chamber placed at every 30°, for a full rotation, with and without HC. Measured MSD was compared with MSD values estimated from the phantom measurements and with the cumulative CTDIvol of the procedure. Results: The median measured MSD was 141 mGy (range 38–410 mGy) while the median cumulative CTDIvol was 72 mGy (range 24–262 mGy). The ratio between the MSD estimated from phantom measurements and the measured MSD was 0.87 (range 0.12–4.1) on average. In 72% of cases the estimated MSD underestimated the measured MSD, while in 28% of the cases it overestimated it. The same trend was observed for the ratio of cumulative CTDIvol and measured MSD. No trend was observed as a function of patient size. Conclusions: On average, estimated MSD from dose rate measurements on phantom as well as from CTDIvol of patient examinations underestimates the measured value of MSD. This can be attributed to deviations of the patient's body habitus from the standard phantom size and to patient positioning in the gantry during the procedure.

Comparison of measured and estimated maximum skin doses during CT fluoroscopy lung biopsies

International Nuclear Information System (INIS)

Zanca, F.; Jacobs, A.; Crijns, W.; De Wever, W.

2014-01-01

Purpose: To measure patient-specific maximum skin dose (MSD) associated with CT fluoroscopy (CTF) lung biopsies and to compare measured MSD with the MSD estimated from phantom measurements, as well as with the CTDIvol of patient examinations. Methods: Data from 50 patients with lung lesions who underwent a CT fluoroscopy-guided biopsy were collected. The CT protocol consisted of a low-kilovoltage (80 kV) protocol used in combination with an algorithm for dose reduction to the radiology staff during the interventional procedure, HandCare (HC). MSD was assessed during each intervention using EBT2 gafchromic films positioned on patient skin. Lesion size, position, total fluoroscopy time, and patient-effective diameter were registered for each patient. Dose rates were also estimated at the surface of a normal-size anthropomorphic thorax phantom using a 10 cm pencil ionization chamber placed at every 30°, for a full rotation, with and without HC. Measured MSD was compared with MSD values estimated from the phantom measurements and with the cumulative CTDIvol of the procedure. Results: The median measured MSD was 141 mGy (range 38–410 mGy) while the median cumulative CTDIvol was 72 mGy (range 24–262 mGy). The ratio between the MSD estimated from phantom measurements and the measured MSD was 0.87 (range 0.12–4.1) on average. In 72% of cases the estimated MSD underestimated the measured MSD, while in 28% of the cases it overestimated it. The same trend was observed for the ratio of cumulative CTDIvol and measured MSD. No trend was observed as a function of patient size. Conclusions: On average, estimated MSD from dose rate measurements on phantom as well as from CTDIvol of patient examinations underestimates the measured value of MSD. This can be attributed to deviations of the patient's body habitus from the standard phantom size and to patient positioning in the gantry during the procedure

Principles for the establishment of upper bounds to doses to individuals from global and regional sources

International Nuclear Information System (INIS)

1989-01-01

The IAEA Safety Guide, Safety Series No. 77 (1986), Principles for Limiting Releases of Radioactive Effluents into the Environment, identifies the concept of upper bounds to individual dose. They are the fractions of the dose limit for members of the public allocated to the various different sources and practices which can give rise to individual exposure. This Guide is concerned with the contributions to individual dose which may arise from other sources in the same region and also from sources which are far away but which, because of the nature of the radionuclides involved, give rise to a global component of dose. Consideration is given to the need for control of such exposures and the means by which it could be achieved. The text may be seen as providing expansion of the guidance given in Safety Series No. 77. 24 refs

Dose-Effect Relationships for Individual Pelvic Floor Muscles and Anorectal Complaints After Prostate Radiotherapy

International Nuclear Information System (INIS)

Smeenk, Robert Jan; Hoffmann, Aswin L.; Hopman, Wim P.M.; Lin, Emile N.J. Th. van; Kaanders, Johannes H.A.M.

2012-01-01

Purpose: To delineate the individual pelvic floor muscles considered to be involved in anorectal toxicity and to investigate dose-effect relationships for fecal incontinence-related complaints after prostate radiotherapy (RT). Methods and Materials: In 48 patients treated for localized prostate cancer, the internal anal sphincter (IAS) muscle, the external anal sphincter (EAS) muscle, the puborectalis muscle (PRM), and the levator ani muscles (LAM) in addition to the anal wall (Awall) and rectal wall (Rwall) were retrospectively delineated on planning computed tomography scans. Dose parameters were obtained and compared between patients with and without fecal urgency, incontinence, and frequency. Dose-effect curves were constructed. Finally, the effect of an endorectal balloon, which was applied in 28 patients, was investigated. Results: The total volume of the pelvic floor muscles together was about three times that of the Awall. The PRM was exposed to the highest RT dose, whereas the EAS received the lowest dose. Several anal and rectal dose parameters, as well as doses to all separate pelvic floor muscles, were associated with urgency, while incontinence was associated mainly with doses to the EAS and PRM. Based on the dose-effect curves, the following constraints regarding mean doses could be deduced to reduce the risk of urgency: ≤30 Gy to the IAS; ≤10 Gy to the EAS; ≤50 Gy to the PRM; and ≤40 Gy to the LAM. No dose-effect relationships for frequency were observed. Patients treated with an endorectal balloon reported significantly less urgency and incontinence, while their treatment plans showed significantly lower doses to the Awall, Rwall, and all pelvic floor muscles. Conclusions: Incontinence-related complaints show specific dose-effect relationships to individual pelvic floor muscles. Dose constraints for each muscle can be identified for RT planning. When only the Awall is delineated, substantial components of the continence apparatus are

Dose-effect relationships for individual pelvic floor muscles and anorectal complaints after prostate radiotherapy.

Science.gov (United States)

Smeenk, Robert Jan; Hoffmann, Aswin L; Hopman, Wim P M; van Lin, Emile N J Th; Kaanders, Johannes H A M

2012-06-01

To delineate the individual pelvic floor muscles considered to be involved in anorectal toxicity and to investigate dose-effect relationships for fecal incontinence-related complaints after prostate radiotherapy (RT). In 48 patients treated for localized prostate cancer, the internal anal sphincter (IAS) muscle, the external anal sphincter (EAS) muscle, the puborectalis muscle (PRM), and the levator ani muscles (LAM) in addition to the anal wall (Awall) and rectal wall (Rwall) were retrospectively delineated on planning computed tomography scans. Dose parameters were obtained and compared between patients with and without fecal urgency, incontinence, and frequency. Dose-effect curves were constructed. Finally, the effect of an endorectal balloon, which was applied in 28 patients, was investigated. The total volume of the pelvic floor muscles together was about three times that of the Awall. The PRM was exposed to the highest RT dose, whereas the EAS received the lowest dose. Several anal and rectal dose parameters, as well as doses to all separate pelvic floor muscles, were associated with urgency, while incontinence was associated mainly with doses to the EAS and PRM. Based on the dose-effect curves, the following constraints regarding mean doses could be deduced to reduce the risk of urgency: ≤ 30 Gy to the IAS; ≤ 10 Gy to the EAS; ≤ 50 Gy to the PRM; and ≤ 40 Gy to the LAM. No dose-effect relationships for frequency were observed. Patients treated with an endorectal balloon reported significantly less urgency and incontinence, while their treatment plans showed significantly lower doses to the Awall, Rwall, and all pelvic floor muscles. Incontinence-related complaints show specific dose-effect relationships to individual pelvic floor muscles. Dose constraints for each muscle can be identified for RT planning. When only the Awall is delineated, substantial components of the continence apparatus are excluded. Copyright © 2012 Elsevier Inc. All rights

MRI-assisted versus conventional treatment planning in brachytherapy of cervical and endometrial carcinoma: The impact of individual anatomy on dose distribution in target volume and organs at risk

International Nuclear Information System (INIS)

Wulf, Joern; Sauer, Otto A.; Herbolsheimer, Michael; Oppitz, Ulrich; Flentje, Michael

1996-01-01

endometrial carcinoma showed, that only 37.5% (min. 35%, max. 39%, volume range from 69cc to 250 cc) of target volume was covered by the reference isodose. The dose to organs at risk, identified with MRI-data, peaked generally higher compared to the estimated or measured dose in conventional treatment planning. MRI-assisted calculated maximum dose to the dorsal bladder wall was 10.35 Gy/fx at mean in cervical- and 6.67 Gy/fx in endometrial carcinoma, while the equivalent doses calculated as ICRU-reference point were 5.4 Gy/fx (cervical-ca.) resp. 5.1 Gy/fx (endometrial-ca). Mean irradiated bladder volume at 7 Gy isodose was 2.9 cc in cervical- and 5 cc in endometrial carcinoma. The mean of the maximum dose to the ventral rectum wall was 8.5 Gy/fx (MRI) vs. 5.1 Gy/fx (ICRU-point) in cervical- and 10.34 Gy/fx (MRI) vs. 2.4 Gy/fx (ICRU) in endometrial carcinoma. The irradiated volume at 7 Gy isodose was smaller than 1 cc in both entities. The irradiated volume and dose to small intestine was not relevant in most patients, however, the 7Gy isodose included 6 cc of small intestine in one patient. Conclusion: Pelvic anatomy differs widely among patients with cervical and endometrial cancer. Standard dose prescription fits only about 50% of patients and might be hazardous for patients with small and insufficient for patients with large uteri. Dose calculation to organs at risk in conventional treatment planning relies on the position of bladder and rectum catheters, where MRI identifies the organs at risk most adjacent to high dose isodose. MRI helps to identify those patients with small or large uteri, who could benefit from an individualized dose prescription. Furthermore, MRI information on dose to target and organs at risk might provide new insight in dose-volume relationships and could improve tumor control probability without compromise to normal tissue complication probability

Method of predicting the mean lung dose based on a patient's anatomy and dose-volume histograms

Energy Technology Data Exchange (ETDEWEB)

Zawadzka, Anna, E-mail: a.zawadzka@zfm.coi.pl [Medical Physics Department, Centre of Oncology, Maria Sklodowska-Curie Memorial Cancer Center, Warsaw (Poland); Nesteruk, Marta [Faculty of Physics, University of Warsaw, Warsaw (Poland); Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich (Switzerland); Brzozowska, Beata [Faculty of Physics, University of Warsaw, Warsaw (Poland); Kukołowicz, Paweł F. [Medical Physics Department, Centre of Oncology, Maria Sklodowska-Curie Memorial Cancer Center, Warsaw (Poland)

2017-04-01

The aim of this study was to propose a method to predict the minimum achievable mean lung dose (MLD) and corresponding dosimetric parameters for organs-at-risk (OAR) based on individual patient anatomy. For each patient, the dose for 36 equidistant individual multileaf collimator shaped fields in the treatment planning system (TPS) was calculated. Based on these dose matrices, the MLD for each patient was predicted by the homemade DosePredictor software in which the solution of linear equations was implemented. The software prediction results were validated based on 3D conformal radiotherapy (3D-CRT) and volumetric modulated arc therapy (VMAT) plans previously prepared for 16 patients with stage III non–small-cell lung cancer (NSCLC). For each patient, dosimetric parameters derived from plans and the results calculated by DosePredictor were compared. The MLD, the maximum dose to the spinal cord (D{sub max} {sub cord}) and the mean esophageal dose (MED) were analyzed. There was a strong correlation between the MLD calculated by the DosePredictor and those obtained in treatment plans regardless of the technique used. The correlation coefficient was 0.96 for both 3D-CRT and VMAT techniques. In a similar manner, MED correlations of 0.98 and 0.96 were obtained for 3D-CRT and VMAT plans, respectively. The maximum dose to the spinal cord was not predicted very well. The correlation coefficient was 0.30 and 0.61 for 3D-CRT and VMAT, respectively. The presented method allows us to predict the minimum MLD and corresponding dosimetric parameters to OARs without the necessity of plan preparation. The method can serve as a guide during the treatment planning process, for example, as initial constraints in VMAT optimization. It allows the probability of lung pneumonitis to be predicted.

10 CFR 20.1502 - Conditions requiring individual monitoring of external and internal occupational dose.

Science.gov (United States)

2010-01-01

... external and internal occupational dose. Each licensee shall monitor exposures to radiation and radioactive... 10 Energy 1 2010-01-01 2010-01-01 false Conditions requiring individual monitoring of external and internal occupational dose. 20.1502 Section 20.1502 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR...

Predictive patient-specific dosimetry and individualized dosing of pretargeted radioimmunotherapy in patients with advanced colorectal cancer

Energy Technology Data Exchange (ETDEWEB)

Schoffelen, Rafke; Woliner-van der Weg, Wietske; Visser, Eric P.; Oyen, Wim J.G.; Boerman, Otto C. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, PO Box 9101, Nijmegen (Netherlands); Goldenberg, David M. [Garden State Cancer Center, Morris Plains, NJ (United States); Immunomedics, Inc., Morris Plains, NJ (United States); IBC Pharmaceuticals, Inc., Morris Plains, NJ (United States); Sharkey, Robert M.; McBride, William J.; Chang, Chien-Hsing [Immunomedics, Inc., Morris Plains, NJ (United States); Rossi, Edmund A. [IBC Pharmaceuticals, Inc., Morris Plains, NJ (United States); Graaf, Winette T.A. van der [Radboud University Medical Center, Department of Medical Oncology, Nijmegen (Netherlands)

2014-08-15

Pretargeted radioimmunotherapy (PRIT) with bispecific antibodies (bsMAb) and a radiolabeled peptide reduces the radiation dose to normal tissues. Here we report the accuracy of an {sup 111}In-labeled pretherapy test dose for personalized dosing of {sup 177}Lu-labeled IMP288 following pretargeting with the anti-CEA x anti-hapten bsMAb, TF2, in patients with metastatic colorectal cancer (CRC). In 20 patients bone marrow absorbed doses (BMD) and doses to the kidneys were predicted based on blood samples and scintigrams acquired after {sup 111}In-IMP288 injection for individualized dosing of PRIT with {sup 177}Lu-IMP288. Different dose schedules were studied, varying the interval between the bsMAb and peptide administration (5 days vs. 1 day), increasing the bsMAb dose (75 mg vs. 150 mg), and lowering the peptide dose (100 μg vs. 25 μg). TF2 and {sup 111}In/{sup 177}Lu-IMP288 clearance was highly variable. A strong correlation was observed between peptide residence times and individual TF2 blood concentrations at the time of peptide injection (Spearman's ρ = 0.94, P < 0.0001). PRIT with 7.4 GBq {sup 177}Lu-IMP288 resulted in low radiation doses to normal tissues (BMD <0.5 Gy, kidney dose <3 Gy). Predicted {sup 177}Lu-IMP288 BMD were in good agreement with the actual measured doses (mean ± SD difference -0.0026 ± 0.028 mGy/MBq). Hematological toxicity was mild in most patients, with only two (10 %) having grade 3-4 thrombocytopenia. A correlation was found between platelet toxicity and BMD (Spearman's ρ = 0.58, P = 0.008). No nonhematological toxicity was observed. These results show that individual high activity doses in PRIT in patients with CEA-expressing CRC could be safely administered by predicting the radiation dose to red marrow and kidneys, based on dosimetric analysis of a test dose of TF2 and {sup 111}In-IMP288. (orig.)

Environmental aspects and public exposure doses of airborne radioactive effluents from a PWR-power plant

International Nuclear Information System (INIS)

Song Miaofa; Zhang Jin; Fu Rongchu; Hu Yinxiu

1989-04-01

It is estimated that the environmental aspects and public exposure doses of airborne radioactive effluents from a imaginary 0.3 GW PWR-power plant which sited on the site of a large coalfired power plant estimated before. The major contributor to public exposure is found to be the release of 14 C and the critical pathway is food ingestion. A maximum annual individual body effective dose equivalent of 7.112 x 10 -6 Sv · (GW · a) -1 is found at the point of 0.5 km southeast of the source. The collective dose equivalent in the area around the plant within a radius of 100 km is to be 0.5974 man-Sv · a) -1 . Both maximum individual and collective effective dose equivalents of the PWR-power plant are much lower than those of the coal-fired one. If the ash emission ratio of the latter decreases from 24.6% to 1%, public exposure doses of the two plants would be nearly equal

Evaluation of dose from external irradiation for individuals living in areas affected by the Fukushima Daiichi nuclear plant accident

International Nuclear Information System (INIS)

Naito, Wataru; Uesaka, Motoki; Yamada, Chie; Ishii, Hideki

2015-01-01

In order to effectively and appropriately manage external radiation doses in the affected areas of Fukushima, it is important to identify when, where and how much exposure occurred. It is also necessary to quantitatively measure external exposure and air dose rates for different activity patterns in individuals living and working in Japanese-style buildings. The authors used a new personal dosemeter (D-shuttle) along with a global positioning system and geographical information system to relate personal dose rate with activity patterns and air dose rate. Hourly individual doses obtained by D-shuttle can provide an effective communication tool for those who want to identify when and how much exposure occurs. Personal monitoring of 26 volunteers showed that personal doses obtained from D-shuttle were ∼30 % of cumulative air dose estimated by data from the airborne monitoring survey. This analysis showed that, for most study volunteers, the exposure from staying at home represented about half of the total cumulative dose. This suggests that even though the peak exposure doses may be observed outside of working hours, to develop appropriate countermeasures for external dose reduction, it is thus important to identify the contributions of individuals' time-activities. This study provides a valuable basis for developing a realistic and pragmatic method to estimate external doses of individuals in Fukushima. (authors)

Cumulative effective and individual organ dose levels in paediatric patients undergoing multiple catheterizations for congenital heart disease

International Nuclear Information System (INIS)

Jones, T.P.; Brennan, P.C.; Ryan, E.

2017-01-01

This study examines the cumulative radiation dose levels received by a group of children who underwent multiple cardiac catheterisation procedures during the investigation and management of congenital heart disease (CHD). The purpose is to calculate cumulative doses, identify higher dose individuals, outline the inconsistencies with risk assessment and encourage the establishment of dose databases in order to facilitate the longitudinal research necessary to better understand health risks. A retrospective review of patient records for 117 paediatric patients who have undergone two or more cardiac catheterizations for the investigation of CHD was undertaken. This cohort consisted of patients who were catheterised over a period from September 2002 to August 2014. The age distribution was from newborn to 17 y. Archived kerma-area product (P KA ) and fluoroscopy time (T) readings were retrieved and analysed. Cumulative effective and individual organ doses were determined. The cumulative P KA levels ranged from 1.8 to 651.2 Gycm 2 , whilst cumulative effective dose levels varied from 2 to 259 mSv. The cumulative fluoroscopy time was shown to vary from 8.1 to 193.5 min. Median cumulative organ doses ranged from 3 to 94 mGy. Cumulative effective dose levels are highly variable but may exceed 250 mSv. Individual organ and effective dose measurements remain useful for comparison purposes between institutions although current methodologies used for determining lifetime risks are inadequate. (authors)

Estimation of dose distribution in occupationally exposed individuals to FDG-18F

International Nuclear Information System (INIS)

Lacerda, Isabelle V. Batista de; Cabral, Manuela O. Monteiro; Vieira, Jose Wilson

2014-01-01

The use of unsealed radiation sources in nuclear medicine can lead to important incorporation of radionuclides, especially for occupationally exposed individuals (OEIs) during production and handling of radiopharmaceuticals. In this study, computer simulation was proposed as an alternative methodology for evaluation of the absorbed dose distribution and for the effective dose value in OEIs. For this purpose, the Exposure Computational Model (ECM) which is named as FSUP (Female Adult Mesh - supine) were used. This ECM is composed of: voxel phantom FASH (Female Adult MeSH) in the supine position, the MC code EGSnrc and an algorithm simulator of general internal source. This algorithm was modified to adapt to specific needs of the positron emission from FDG- 18 F. The obtained results are presented as absorbed dose/accumulated activity. To obtain the absorbed dose distribution it was necessary to use accumulative activity data from the in vivo bioassay. The absorbed dose distribution and the value of estimated effective dose in this study did not exceed the limits for occupational exposure. Therefore, the creation of a database with the distribution of accumulated activity is suggested in order to estimate the absorbed dose in radiosensitive organs and the effective dose for OEI in similar environment. (author)

The MLC tongue-and-groove effect on IMRT dose distributions

Energy Technology Data Exchange (ETDEWEB)

Deng Jun [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305 (United States). E-mail: jun@reyes.stanford.edu; Pawlicki, Todd; Chen Yan; Li Jinsheng; Jiang, Steve B.; Ma, C.-M. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305 (United States)

2001-04-01

We have investigated the tongue-and-groove effect on the IMRT dose distributions for a Varian MLC. We have compared the dose distributions calculated using the intensity maps with and without the tongue-and-groove effect. Our results showed that, for one intensity-modulated treatment field, the maximum tongue-and-groove effect could be up to 10% of the maximum dose in the dose distributions. For an IMRT treatment with multiple gantry angles ({>=} 5), the difference between the dose distributions with and without the tongue-and-groove effect was hardly visible, less than 1.6% for the two typical clinical cases studied. After considering the patient setup errors, the dose distributions were smoothed with reduced and insignificant differences between plans with and without the tongue-and-groove effect. Therefore, for a multiple-field IMRT plan ({>=} 5), the tongue-and-groove effect on the IMRT dose distributions will be generally clinically insignificant due to the smearing effect of individual fields. The tongue-and-groove effect on an IMRT plan with small number of fields (<5) will vary depending on the number of fields in a plan (coplanar or non-coplanar), the MLC leaf sequences and the patient setup uncertainty, and may be significant (>5% of maximum dose) in some cases, especially when the patient setup uncertainty is small ({<=} 2 mm). (author)

Reconstruction of individual doses in population evacuated from Pripyat based on imitation stochastic model

International Nuclear Information System (INIS)

Chumak, V.V.

1998-01-01

Imitation stochastic approach to the reconstruction of individual doses of a large group of irradiated population (12632 persons) was used for the first time,evaluation of uncertainty of the obtained results was made. When the error of the dose reconstruction is small, the method is reliable providing a high accuracy of the results

Individual dose and exposure of Italian children to ultrafine particles.

Science.gov (United States)

Buonanno, G; Marini, S; Morawska, L; Fuoco, F C

2012-11-01

Time-activity patterns and the airborne pollutant concentrations encountered by children each day are an important determinant of individual exposure to airborne particles. This is demonstrated in this work by using hand-held devices to measure the real-time individual exposure of more than 100 children aged 8-11 years to particle number concentrations and average particle diameter, as well as alveolar and tracheobronchial deposited surface area concentration. A GPS-logger and activity diaries were also used to give explanation to the measurement results. Children were divided in three sample groups: two groups comprised of urban schools (school time from 8:30 am to 1:30 pm) with lunch and dinner at home, and the third group of a rural school with only dinner at home. The mean individual exposure to particle number concentration was found to differ between the three groups, ranging from 6.2 × 10(4)part.cm(-3) for children attending one urban school to 1.6 × 10(4)part.cm(-3) for the rural school. The corresponding daily alveolar deposited surface area dose varied from about 1.7 × 10(3)mm(2) for urban schools to 6.0 × 10(2)mm(2) for the rural school. For all of the children monitored, the lowest particle number concentrations are found during sleeping time and the highest were found during eating time. With regard to alveolar deposited surface area dose, a child's home was the major contributor (about 70%), with school contributing about 17% for urban schools and 27% for the rural school. An important contribution arises from the cooking/eating time spent at home, which accounted for approximately 20% of overall exposure, corresponding to more than 200 mm(2). These activities represent the highest dose received per time unit, with very high values also encountered by children with a fireplace at home, as well as those that spend considerable time stuck in traffic jams. Copyright © 2012 Elsevier B.V. All rights reserved.

Monitoring and assessment of individual doses of occupationally exposed workers due to intake of radionuclides

International Nuclear Information System (INIS)

Alexander, O. A.

2014-04-01

Monitoring and estimation of individual intakes of radionuclides can be complex. Doses of intakes cannot be measured directly, however must be assessed from the monitoring data of the individual. The individual monitoring data includes whole body counting, excretion analysis (urine or faecal). In the estimation of these data requires that the assessor makes assumptions about the exposure scenario, including the pattern and mode of radionuclide intake. Also physicochemical characteristics of the material involved and the period of time between exposure and measurement. This project report seeks to provide some underlying guidance on monitoring programmes and data interpretation using case study. In this present study the committed effective dose (CED) 1.20mSv exceeded the recording level (i.e. 1mSv) however it was below the investigation level (i.e. 2mSv). The present study recommends that as an essential part in internal dosimetry, specialists be capable of recognizing conditions warranting follow-up bioassay and dose evaluation. Personnel should be familiar with the relevant internal dosimetry literature and the recommendations of national and international scientific organizations with regard to internal dose. (au)

Personal monitoring and assessment of doses received by radiation workers

International Nuclear Information System (INIS)

Swindon, T.N.; Morris, N.D.

1981-12-01

The Personal Radiation Monitoring Service operated by the Australian Radiation Laboratory is outlined and the types of monitors used for assessment of doses received by radiation workers are described. The distribution of doses received by radiation workers in different occupational categories is determined. From these distributions, the average doses received have been assessed and the maximum likely additional increase in cancer deaths in Australia as a result of occupational exposure estimated. This increase is shown to be very small. There is, however, a considerable spread of doses received by individuals within occupational groups

Validation of calculated tissue maximum ratio obtained from measured percentage depth dose (PPD) data for high energy photon beam ( 6 MV and 15 MV)

International Nuclear Information System (INIS)

Osei, J.E.

2014-07-01

During external beam radiotherapy treatments, high doses are delivered to the cancerous cell. Accuracy and precision of dose delivery are primary requirements for effective and efficiency in treatment. This leads to the consideration of treatment parameters such as percentage depth dose (PDD), tissue air ratio (TAR) and tissue phantom ratio (TPR), which show the dose distribution in the patient. Nevertheless, tissue air ratio (TAR) for treatment time calculation, calls for the need to measure in-air-dose rate. For lower energies, measurement is not a problem but for higher energies, in-air measurement is not attainable due to the large build-up material required for the measurement. Tissue maximum ratio (TMR) is the quantity required to replace tissue air ratio (TAR) for high energy photon beam. It is known that tissue maximum ratio (TMR) is an important dosimetric function in radiotherapy treatment. As the calculation methods used to determine tissue maximum ratio (TMR) from percentage depth dose (PDD) were derived by considering the differences between TMR and PDD such as geometry and field size, where phantom scatter or peak scatter factors are used to correct dosimetric variation due to field size difference. The purpose of this study is to examine the accuracy of calculated tissue maximum ratio (TMR) data with measured TMR values for 6 MV and 15 MV photon beam at Sweden Ghana Medical Centre. With the help of the Blue motorize water phantom and the Omni pro-Accept software, Pdd values from which TMRs are calculated were measured at 100 cm source-to-surface distance (SSD) for various square field sizes from 5x5 cm to 40x40 cm and depth of 1.5 cm to 25 cm for 6 MV and 15 MV x-ray beam. With the same field sizes, depths and energies, the TMR values were measured. The validity of the calculated data was determined by making a comparison with values measured experimentally at some selected field sizes and depths. The results show that; the reference depth of maximum

Estimated radiation dose from timepieces containing tritium

International Nuclear Information System (INIS)

McDowell-Boyer, L.M.

1980-01-01

Luminescent timepieces containing radioactive tritium, either in elemental form or incorporated into paint, are available to the general public. The purpose of this study was to estimate potential radiation dose commitments received by the public annually as a result of exposure to tritium which may escape from the timepieces during their distribution, use, repair, and disposal. Much uncertainty is associated with final dose estimates due to limitations of empirical data from which exposure parameters were derived. Maximum individual dose estimates were generally less than 3 μSv/yr, but ranged up to 2 mSv under worst-case conditions postulated. Estimated annual collective (population) doses were less than 5 person/Sv per million timepieces distributed

Calculations of individual doses for Techa River Cohort members exposed to atmospheric radioiodine from Mayak releases

Energy Technology Data Exchange (ETDEWEB)

Napier, Bruce A.; Eslinger, Paul W.; Tolstykh, Evgenia I.; Vorobiova, Marina I.; Tokareva, Elena E.; Akhramenko, Boris N.; Krivoschapov, Victor A.; Degteva, Marina O.

2017-11-01

Time-dependent thyroid doses were reconstructed for Techa River Cohort members living near the Mayak production facilities from 131I released to the atmosphere for all relevant exposure pathways. The calculational approach uses four general steps: 1) construct estimates of releases of 131I to the air from production facilities; 2) model the transport of 131I in the air and subsequent deposition on the ground and vegetation; 3) model the accumulation of 131I in soil, water, and food products (environmental media); and 4) calculate individual doses by matching appropriate lifestyle and consumption data for the individual to concentrations of 131I in environmental media. The dose calculations are implemented in a Monte Carlo framework that produces best estimates and confidence intervals of dose time-histories. The 131I contribution was 75-99% of the thyroid dose. The mean total thyroid dose for cohort members was 193 mGy and the median was 53 mGy. Thyroid doses for about 3% of cohort members were larger than 1 Gy. About 7% of children born in 1940-1950 had doses larger than 1 Gy. The uncertainty in the 131I dose estimates is low enough for this approach to be used in regional epidemiological studies.

Individual doses from radionuclides released to the Baltic coast

International Nuclear Information System (INIS)

Bergstroem, U.; Nordlinder, S.

1991-01-01

Individual doses to critical groups from a continuous unit release of nuclides from high-level waste to a coast area were calculated. The selection of nuclides for this study was based on experience of their importance from a radiological point of view. The coastal area should be representative for average conditions along the Swedish Baltic coast. The costal area was simulated in the model by compartments for water and sediment, respectively. Six exposure pathways for activity from the water and sediment reservoirs were considered. The ecosystem was assumed to be similar to present conditions in Sweden. This was also the case concerning diet and living habits. In addition, the doses from naturally occurring nuclides in the uranium decay chains were calculated, based on natural levels. The calculations were carried out with the BIOPATH and PRISM codes. The latter code was used to obtain the uncertainty in the results due to the uncertainty in the input parameter values. (au) (34 refs., 15 tbls.)

Establishing an individual dosing system for patients undergoing interventional transcatheter arterial embolization: Radiochromic film and Monte Carlo simulation

International Nuclear Information System (INIS)

Tsai, Hui-Yu; Lai, Pei-Ling; Li, Yang-Ying; Tyan, Yeu-Sheng

2011-01-01

Less invasive imaging-guided vascular interventions with fluoroscopy and digital subtraction angiography have recently become widespread and have been successfully used for treating various diseases. However, interventional fluoroscopy procedures may present deterministic and stochastic radiation risks. The International Commission on Radiological Protection (ICRP) and the Food and Drug Administration have requested identifying procedures that may involve patient doses greater than the recommended thresholds. In this study, radiochromic dosimetric media, known as self-developing films, and measurement-based Monte Carlo simulations were used to establish an interventional radiology dosing system for individual patients undergoing interventional transcatheter arterial embolization. The peak skin dose, evaluated from the entrance surface dose distribution, was 21% less than the cumulated dose reported from the console. A 3D dose map incorporated into CT images was established. The organ doses and effective doses for individual patients were evaluated using this dosing system. This system could be applied very well to other fluoroscopic or interventional procedures for patient dose management.

Population pharmacokinetics and maximum a posteriori probability Bayesian estimator of abacavir: application of individualized therapy in HIV-infected infants and toddlers.

NARCIS (Netherlands)

Zhao, W.; Cella, M.; Pasqua, O. Della; Burger, D.M.; Jacqz-Aigrain, E.

2012-01-01

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Abacavir is used to treat HIV infection in both adults and children. The recommended paediatric dose is 8 mg kg(-1) twice daily up to a maximum of 300 mg twice daily. Weight was identified as the central covariate influencing pharmacokinetics of abacavir in

[MAXIMUM SINGLE DOSE OF COLLOIDAL SILVER NEGATIVELY AFFECTS ERYTHROPOIESIS IN VITRO].

Science.gov (United States)

Tishevskayal, N V; Zakharovl, Y M; Bolotovl, A A; Arkhipenko, Yu V; Sazontova, T G

2015-01-01

Erythroblastic islets (EI) of rat bone marrow were cultured for 24 h in the presence of silver nanoparticles (1.07 · 10(-4) mg/ml; 1.07 · 10(-3) mg/ml; and 1.07 · 10(-2) mg/mL). The colloidal silver at 1.07 · 10(-3) mg/ml concentration inhibited the formation of new Elby disrupting contacts of bone marrow macrophages with CFU-E (erythropoiesis de novo) by 65.3% (p Colloidal silver nanoparticles suppressed the reconstruction of erythropoiesis and inhibited the formation of new EI by disrupting contacts of CFU-E and central macrophages with matured erythroidal "crown" (erythropoiesis de repeto). The colloidal silver concentration of 1.07 · 10(-3) mg/ml in the culture medium also reduced the number of self-reconstructing EI by 67.5% (p colloidal silver reduced this value by 93.7% (p Silver nanoparticles retarded maturation of erythroid cells at the stage of oxiphylic normoblast denucleation: 1.07 · 10(-3) mg/ml colloidal silver increased the number of mature El by 53% (p colloidal silver in concentration equivalent to the maximum single dose is related to the effect of silver nanoparticles rather than glycerol present in the colloidal suspension.

Effect of changes of personal interview data on estimation of individual thyroid dose

International Nuclear Information System (INIS)

Tret'yakevich, S.S.

2008-01-01

Results of initial and second personal interviews are analyzed for more than one thousand men. Change of individual thyroid dose is considered as consequence of changes of personal interview data. (authors)

Evaluation of the occupational dose in hemodynamic procedures

International Nuclear Information System (INIS)

Silva, Amanda J. da; Fernandes, Ivani M.; Sordi, Gian Maria A.A.; Carneiro, Janete C. Gaburo

2010-01-01

The purpose of this study was to evaluate the dose received by health professionals in a hemodynamic service. It was necessary to know the profile of these professional, to carry out a survey the occupational external doses during the years 2000 to 2009 and to evaluate the distribution of the effective dose from the special procedures guided by fluoroscopy. A self-applied questionnaire was used to delineate the profile of health professionals, taking into account variables such as gender, age, individual monitoring time, number of jobs and tasks performed in the sector. In addition, it was performed an examination of the external individual monitoring doses from the records of the institution. The sample was composed of 35 professionals, 11 males and 24 females, with mean age of (43.0 +- 10.4) years. The average monitoring time of individuals analyzed within the institution was (11.3 +- 9.1) years, considering the period before the study. The minimum record dose level was 0.2 mSv and the maximum dose was 22.7 mSv. Doctors and nursing assistants were the professionals more exposed to radiation, due probably remaining closer to the examination table and X-ray tube during the interventional procedure. (author)

Estimates of the individual and collective doses in consumer products containing radioactive substances

International Nuclear Information System (INIS)

Eleveld, H.; Pruppers, M.J.M.

2000-01-01

Here, consumer products refer to products in which radionuclides have been intentionally incorporated and which can be supplied to members of the public without special surveillance. This group of products includes, for instance, ionisation smoke detectors and timepieces with radium-painted dials. These products can cause a radiation dose to members of the public in various stages of life. In 1996 the European Council laid down basic safety standards in Directive 96/29/Euratom for protecting the health of the general public from the dangers arising from ionising radiation. The Directive contains activity concentrations and total activity per radionuclide, the so-called exemption levels, below which a practice using this radionuclide is exempted from the duty to report. Implementing the Directive in the framework of Dutch legislation, the proposed policy for consumer products is to show a distinction between products with activity concentrations and total activity above and below the exemption levels. Besides the exemption levels being used as activity criteria for the consumer products, two dose criteria an individual dose of 10 microSv/a and a collective dose of 1 manSv/a are also employed. In the study leading to this report, the most recent information on consumer products was first collected and the activity per product, and in some cases also the activity concentration, was tested against the exemption levels. Next, the expected individual and collective doses for members of the public were calculated in the storage and trade phase, as well as the user and disposal phase of the consumer products. In the storage and trade phase, the dose for shop personnel was also estimated. Finally, the doses ware tested against the dose criteria. Gas mantles, static elimination devices, gaseous tritium light sources (GTLS), ceramic tiles, welding rods and camera lenses and eyepieces (belongs to the consumer products for which at least one of the activity criteria is exceeded

Individualized FSH dosing based on ovarian reserve testing in women starting IVF/ICSI : A multicentre trial and cost-effectiveness analysis

NARCIS (Netherlands)

van Tilborg, Theodora C.; Oudshoorn, Simone C.; Eijkemans, Marinus J. C.; Mochtar, Monique H.; van Golde, Ron J. T.; Hoek, Annemieke; Kuchenbecker, Walter K. H.; Fleischer, Kathrin; de Bruin, Jan Peter; Groen, Henk; van Wely, Madelon; Lambalk, Cornelis B.; Laven, Joop S. E.; Mol, Ben Willem J.; Broekmans, Frank J. M.; Torrance, Helen L.

2017-01-01

STUDY QUESTION: Is there a difference in live birth rate and/or cost-effectiveness between antral follicle count (AFC)-based individualized FSH dosing or standard FSH dosing in women starting IVF or ICSI treatment? SUMMARY ANSWER: In women initiating IVF/ICSI, AFC-based individualized FSH dosing

Individualized FSH dosing based on ovarian reserve testing in women starting IVF/ICSI: a multicentre trial and cost-effectiveness analysis

NARCIS (Netherlands)

van Tilborg, Theodora C.; Oudshoorn, Simone C.; Eijkemans, Marinus J. C.; Mochtar, Monique H.; van Golde, Ron J. T.; Hoek, Annemieke; Kuchenbecker, Walter K. H.; Fleischer, Kathrin; de Bruin, Jan Peter; Groen, Henk; van Wely, Madelon; Lambalk, Cornelis B.; Laven, Joop S. E.; Mol, Ben Willem J.; Broekmans, Frank J. M.; Torrance, Helen L.

2017-01-01

STUDY QUESTION: Is there a difference in live birth rate and/or cost-effectiveness between antral follicle count (AFC)-based individualized FSH dosing or standard FSH dosing in women starting IVF or ICSI treatment? SUMMARY ANSWER: In women initiating IVF/ICSI, AFC-based individualized FSH dosing

EPR spectrum deconvolution and dose assessment of fossil tooth enamel using maximum likelihood common factor analysis

International Nuclear Information System (INIS)

Vanhaelewyn, G.; Callens, F.; Gruen, R.

2000-01-01

In order to determine the components which give rise to the EPR spectrum around g = 2 we have applied Maximum Likelihood Common Factor Analysis (MLCFA) on the EPR spectra of enamel sample 1126 which has previously been analysed by continuous wave and pulsed EPR as well as EPR microscopy. MLCFA yielded agreeing results on three sets of X-band spectra and the following components were identified: an orthorhombic component attributed to CO - 2 , an axial component CO 3- 3 , as well as four isotropic components, three of which could be attributed to SO - 2 , a tumbling CO - 2 and a central line of a dimethyl radical. The X-band results were confirmed by analysis of Q-band spectra where three additional isotropic lines were found, however, these three components could not be attributed to known radicals. The orthorhombic component was used to establish dose response curves for the assessment of the past radiation dose, D E . The results appear to be more reliable than those based on conventional peak-to-peak EPR intensity measurements or simple Gaussian deconvolution methods

Exposure dose estimation of nursing personnel and visitors following "1"2"5I brachytherapy

International Nuclear Information System (INIS)

Nakazato, Kazuhisa; Kikuchi, Hirosumi; Hotta, Harumi; Nishizawa, Kunihide

2007-01-01

An automated access management system to the controlled sickrooms for "1"2"5I brachytherapy was developed. The system consists of access control and video surveillance units. The patients implanted "1"2"5I seeds were isolated for about 20 h after surgery in the controlled sickrooms. The maximum doses and dose rates of the nurses and visitors were estimated by using the legal upper limit activity of 1,300 MBq, the measured longest staying time, and the shortest distance between the patients and individuals. Video analysis revealed activities of the nurses, patients, and visitors in the controlled sickroom, and relationships between the access frequency and staying time. The nurses' measured doses ranged from 1 to 3 μSv, and averaged 1.6 μSv. The nurses' maximum dose and dose rate were 16 μSv and 5.6 nSv·h"-"1·MBq"-"1. The visitors' maximum dose and dose rate were 6 μSv and 2.6 nSv·h"-"1·MBq"-"1. The nurses and visitors' exposure doses per patient were estimated to be negligible compared with the annual limit of the public. (author)

Occupational dose at Rokkasho reprocessing plant (RRP)

International Nuclear Information System (INIS)

Takashima, F.; Taguchi, R.; Kano, M.; Moriyama, T.; Ogaki, K.; Noda, K.

2008-01-01

In Japan, Rokkasho Reprocessing Plant (RRP) is going to start the operation in service as the first large-scale commercial reprocessing plant of spent fuels that has annual reprocessing quantity of 800tU pr in maximum. The occupational external exposure is controlled for the purpose of keeping dose as low as reasonably achievable, and it is monitored by the personal dosimeter. On the other hand, the occupational internal exposure is controlled for the purpose of preventing, and it is monitored by the periodical evaluation of internal dose from the radioactive concentration in air of workplace. The individual doses of radiation workers are less than the dose limits in the statute and our lower management values enough. Dose data will be stored continuously and the rational management method will be examined. (author)

Dose-response relationship of autonomic nervous system responses to individualized training impulse in marathon runners.

Science.gov (United States)

Manzi, Vincenzo; Castagna, Carlo; Padua, Elvira; Lombardo, Mauro; D'Ottavio, Stefano; Massaro, Michele; Volterrani, Maurizio; Iellamo, Ferdinando

2009-06-01

In athletes, exercise training induces autonomic nervous system (ANS) adaptations that could be used to monitor training status. However, the relationship between training and ANS in athletes has been investigated without regard for individual training loads. We tested the hypothesis that in long-distance athletes, changes in ANS parameters are dose-response related to individual volume/intensity training load and could predict athletic performance. A spectral analysis of heart rate (HR), systolic arterial pressure variability, and baroreflex sensitivity by the sequences technique was investigated in eight recreational athletes during a 6-mo training period culminating with a marathon. Individualized training load responses were monitored by a modified training impulse (TRIMP(i)) method, which was determined in each athlete using the individual HR and lactate profiling determined during a treadmill test. Monthly TRIMP(i) steadily increased during the training period. All the ANS parameters were significantly and very highly correlated to the dose of exercise with a second-order regression model (r(2) ranged from 0.90 to 0.99; P marathon. These results suggest that in recreational athletes, ANS adaptations to exercise training are dose related on an individual basis, showing a progressive shift toward a sympathetic predominance, and that LF oscillations in HRV at peak training load could predict athletic achievement in this athlete population.

Production and bromatologic composition of grass-mombaça (Panicum maximum Jacq., submitted to different sources and doses of acidity corrective / Produção e composição bromatológica da forragem do capim-mombaça (Panicum maximum Jacq., submetidos a diferentes fontes e doses de corretivo de acidez

Directory of Open Access Journals (Sweden)

Francisco Maximino Fernandes

2010-04-01

Full Text Available The experiment was carried in protected (greenhouse atmosphere, in University of Engineering, UNESP of Ilha Solteira-SP, with the objective of evaluating sources (limestone and calcium silicate slag and doses (0,0 – 0,5 – 1,0 – 1,5 – 2,0 times the recommended dose of corrective in the bromatologic composition, tillering and production of dry matter of the grass mombaça (Panicum maximum Jacq.. The lineation was completely randomized design, with four repetitions. It was evaluated the tiller number, the production of dry matter, the gross protein, neutral detergent fiber (NDF and acid detergent fiber (ADF. The corrective influenced the tillering in almost all of the countings. The limestone provided larger production of dry matter in the doses of 1,5 and 2,0 times the recommended dose. The bromatologic composition of the forage was not influenced by the corrective and doses.O experimento foi conduzido em ambiente protegido (estufa, na Faculdade de Engenharia, UNESP de Ilha Solteira, com o objetivo de avaliar fontes (calcário e escória silicatada e doses (0,0 – 0,5 – 1,0 – 1,5 – 2,0 vezes a dose recomendada de corretivos na composição bromatológica, perfilhamento e produção de matéria seca do capim-mombaça (Panicum maximum Jacq.. O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições. Avaliou-se o número de perfilhos, a produção de matéria seca e os teores de proteína bruta (PB, fibra em detergente neutro (FDN e fibra em detergente ácido (FDA. Os corretivos influenciaram o perfilhamento em quase todas as contagens. O calcário proporcionou maior produção de matéria seca nas doses de 1,5 e 2,0 vezes a dose recomendada. A composição bromatológica da forragem não foi influenciada pelos corretivos e doses utilizadas.

EDO, Doses to Man and Organs from Reactor Operation Noble Gas and Liquid Waste Release

International Nuclear Information System (INIS)

Rodenas Diago, Jose; Serradell Garcia, Vicente

1983-01-01

1 - Description of problem or function: EDO evaluates individual and collective doses to man from atmospheric releases of noble gases and other gaseous effluents. 2 - Method of solution: The dose calculations are carried out by following the guide- lines of USNRC Regulatory Guide 1.109. Radiation exposure for maximum individuals and population are estimated within 30 km from the nuclear plant. This area is divided into 160 circular trapezoids, to which computations are referred. Four age groups, seven organs for internal dose and two for external dose have been considered. Dose calculations are done through 14 pathways, 7 for liquid effluents, one for noble gases, and 6 for the rest of gaseous effluents. 3 - Restrictions on the complexity of the problem: The following are the maximum dimension sizes preset in the code: 73 radionuclides (other than noble gases); 15 noble gases; 160 circular trapezoids; 31 chemical elements; 4 types of aquatic foods; 15 points of exposure for shorelines; 15 trapezoids influenced by each point; 4 terrestrial food pathways; 100 centres of population. Some of these limits can be varied

EDO, Doses to Man and Organs from Reactor Operation Noble Gas and Liquid Waste Release

Energy Technology Data Exchange (ETDEWEB)

Rodenas Diago, Jose; Serradell Garcia, Vicente [Departamento de Ingenieria Nuclear, Escuela Tecnica Superior de Ingenieros Industriales, Universidad Politecnica, Camino de Vera 2/n Apartado 2012, Valencia (Spain)

1983-10-18

1 - Description of problem or function: EDO evaluates individual and collective doses to man from atmospheric releases of noble gases and other gaseous effluents. 2 - Method of solution: The dose calculations are carried out by following the guide- lines of USNRC Regulatory Guide 1.109. Radiation exposure for maximum individuals and population are estimated within 30 km from the nuclear plant. This area is divided into 160 circular trapezoids, to which computations are referred. Four age groups, seven organs for internal dose and two for external dose have been considered. Dose calculations are done through 14 pathways, 7 for liquid effluents, one for noble gases, and 6 for the rest of gaseous effluents. 3 - Restrictions on the complexity of the problem: The following are the maximum dimension sizes preset in the code: 73 radionuclides (other than noble gases); 15 noble gases; 160 circular trapezoids; 31 chemical elements; 4 types of aquatic foods; 15 points of exposure for shorelines; 15 trapezoids influenced by each point; 4 terrestrial food pathways; 100 centres of population. Some of these limits can be varied.

Offsite radiation doses summarized from Hanford environmental monitoring reports for the years 1957-1984

International Nuclear Information System (INIS)

Soldat, J.K.; Price, K.R.; McCormack, W.D.

1986-02-01

Since 1957, evaluations of offsite impacts from each year of operation have been summarized in publicly available, annual environmental reports. These evaluations included estimates of potential radiation exposure to members of the public, either in terms of percentages of the then permissible limits or in terms of radiation dose. The estimated potential radiation doses to maximally exposed individuals from each year of Hanford operations are summarized in a series of tables and figures. The applicable standard for radiation dose to an individual for whom the maximum exposure was estimated is also shown. Although the estimates address potential radiation doses to the public from each year of operations at Hanford between 1957 and 1984, their sum will not produce an accurate estimate of doses accumulated over this time period. The estimates were the best evaluations available at the time to assess potential dose from the current year of operation as well as from any radionuclides still present in the environment from previous years of operation. There was a constant striving for improved evaluation of the potential radiation doses received by members of the public, and as a result the methods and assumptions used to estimate doses were periodically modified to add new pathways of exposure and to increase the accuracy of the dose calculations. Three conclusions were reached from this review: radiation doses reported for the years 1957 through 1984 for the maximum individual did not exceed the applicable dose standards; radiation doses reported over the past 27 years are not additive because of the changing and inconsistent methods used; and results from environmental monitoring and the associated dose calculations reported over the 27 years from 1957 through 1984 do not suggest a significant dose contribution from the buildup in the environment of radioactive materials associated with Hanford operations

Assessment of individual doses and intervention planning at CERN

International Nuclear Information System (INIS)

Brugger, M.; Forkel-Wirth, D.; Gaborit, J.C.; Menzel, H.; Roesler, S.

2006-01-01

Founded in 1954, CERN is the European Organization for Nuclear Research, one of the world's largest international particle physics centres. It sits astride the Franco-Swiss border near Geneva. The Large Hadron Collider (LHC) is currently being installed in a 27-kilometer ring tunnel, buried deep below the countryside on the outskirts of Geneva, Switzerland and the Pays de Gex, France. When its operation begins in 2007, the LHC will be the world's most power particle accelerator. The start-up and the operation of the LHC will mark a new era for CERN's operational radiation protection. The total surface of CERN's radiation areas will enlarge significantly and a large number of work places have to be regularly monitored by CERN's radiation protection group. The maintenance personnel will comprise CERN staff, outside contractors and a large number of physicists from all over the world. CERN meets this challenge by applying optimisation processes already in the design of accelerator and detector components and by an appropriate intervention and dose planning during operation. Detailed Monte Carlo calculations were performed during the design phase of the LHC and were used to identify the potential radiation hazards during future maintenance in areas with elevated beam losses (accelerator ejection and injection, beam dumps, target areas or beam cleaning insertions) and thus elevated dose rates. In an iterative way, the design of the accelerator components and the layout of these regions were optimised. The impact of the proposed modifications on the dose to personnel was evaluated by Monte Carlo simulations. Calculated individual and collective doses were then compared to design constraints. (author)

Assessment of Individual Doses and Intervention Planning at CERN

International Nuclear Information System (INIS)

Brugger, M.; Forkel-Wirth, D.; Gaborit, J.C.; Menzel, H.; Roesler, S.; Vincke, H.

2006-01-01

Founded in 1954, CERN is the European Organization for Nuclear Research, one of the world's largest international particle physics centres. It sits astride the Franco-Swiss border near Geneva. The Large Hadron Collider (Lhc) is currently being installed in a 27-kilometer ring tunnel, buried deep below the countryside on the outskirts of Geneva, Switzerland and the Pays de Gex, France. When its operation begins in 2007, the Lhc will be the world's most powerful particle accelerator. The start-up and the operation of the Lhc will mark a new era for CERN's operational radiation protection. The total surface of CERN's radiation areas will enlarge significantly and a large number of work places have to be regularly monitored by CERN's radiation protection group. The maintenance personnel will comprise CERN staff, outside contractors and a large number of physicists from all over the world. CERN meets this challenge by applying optimisation processes already in the design of accelerator and detector components and by an appropriate intervention and dose planning during operation. Detailed Monte Carlo calculations were performed during the design phase of the Lhc and were used to identify the potential radiation hazards during future maintenance in areas with elevated beam losses (accelerator ejection and injection, beam dumps, target areas or beam cleaning insertions) and thus elevated dose rates. In an iterative way, the design of the accelerator components and the layout of these regions were optimised. The impact of the proposed modifications on the dose to personnel was evaluated by Monte Carlo simulations. Calculated individual and collective doses were then compared to design constraints. (authors)

Individual dose burden evaluation in the residents of the vicinity of Semipalatinsk nuclear test site

International Nuclear Information System (INIS)

Lipikhina, A.V.; Valivach, M.N.; Kurakina, N.N.; Kosatov, V.G.; Federbush, E.G.; Bugembayeva, M.D.

2003-01-01

Full text: The evaluation of individual dose burden can be make by an estimation method based on the following parameters: - dose rate in the concrete settlement after concrete explosion; - time of stay of an individual under a cloud; - behavior of the individual in the subsequent time; - diet. The archive and published materials available today have these input parameters. At the same time, these materials have significant gaps, and are very contradictory. For example, the available published data on the explosion made on 24.09.1951 (the main dose forming explosion in Kainar) have the following data ranges: - gamma-radiation dose rate at 24 hours after explosion (71.3-304) mR/h; out-door time in an adult man - (6-16) h/day in the summer, (3-16) h/day in the winter; - consumption of milk by an adult man - (0.2-1) l/day. The time of stay of an individual under a cloud depends on the distance from epicenter to settlement and on wind velocity at the time of explosion. For explosion 24.09.1951 the following data have been published: distance from epicenter to settlement Kainar- (139-150) km; wind velocity-(15.0-26.4) km/h. Based on these ranges of data we can obtain, for example, the effective external gamma exposure dose estimates in an adult man (office worker), which range from 2.6 to 23.4 cSv. To verify these input data, we have determined: the distance from epicenter to settlement Kainar. This was made using electronic maps of Kazakhstan (SN ISBN 5-94552-085-x), and also the data of geographic coordinates database of the Russian Ministry of Emergency Situations. The distance is 142.1 km; the wind velocity based on the archive data of the Kazakh Regional State Weather Center, which was 15 km /h; - the out-door time in an adult man (office worker) was determined based on the results of an interview of Kainar residents. The out-door time in the adult was 6.859 h/day in the summer and 4.598 h/day in the winter. Based on these verified data the effective external gamma

Estimation of dose distribution in occupationally exposed individuals to FDG-{sup 18}F

Energy Technology Data Exchange (ETDEWEB)

Lacerda, Isabelle V. Batista de; Cabral, Manuela O. Monteiro; Vieira, Jose Wilson, E-mail: ilacerda.bolsista@cnen.gov.br, E-mail: manuela.omc@gmail.com [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Oliveira, Mercia Liane de; Andrade Lima, Fernando R. de, E-mail: falima@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

2014-07-01

The use of unsealed radiation sources in nuclear medicine can lead to important incorporation of radionuclides, especially for occupationally exposed individuals (OEIs) during production and handling of radiopharmaceuticals. In this study, computer simulation was proposed as an alternative methodology for evaluation of the absorbed dose distribution and for the effective dose value in OEIs. For this purpose, the Exposure Computational Model (ECM) which is named as FSUP (Female Adult Mesh - supine) were used. This ECM is composed of: voxel phantom FASH (Female Adult MeSH) in the supine position, the MC code EGSnrc and an algorithm simulator of general internal source. This algorithm was modified to adapt to specific needs of the positron emission from FDG-{sup 18}F. The obtained results are presented as absorbed dose/accumulated activity. To obtain the absorbed dose distribution it was necessary to use accumulative activity data from the in vivo bioassay. The absorbed dose distribution and the value of estimated effective dose in this study did not exceed the limits for occupational exposure. Therefore, the creation of a database with the distribution of accumulated activity is suggested in order to estimate the absorbed dose in radiosensitive organs and the effective dose for OEI in similar environment. (author)

Individualized Dosing of Children's Liquid Medications in the Community Pharmacy Setting: A Survey of Parents and Guardians

Directory of Open Access Journals (Sweden)

Jamie Shelly

2013-01-01

Full Text Available Objectives: 1 To determine parents' and/or guardians' interest in having pharmacists provide children's liquid medications in a pre-measured, individualized dosing device 2 To assess parents' and/or guardians' perception of dosing liquid medications for a child. Design: Observational survey Setting: Regional chain pharmacy in North Carolina Participants: > 18 years old, parent/guardian of a childchain, responsible for administering child's liquid medication Intervention: 14 item questionnaire Main Outcome Measure: Interest in pharmacists providing children's liquid medications in pre-measured, individualized dosing devices Results: 250 questionnaires were mailed; 42 were marked "return to sender" (16.8%, 22 were returned completed (10.6%, and 20 of the 22 met inclusion criteria (9.6%. 95% of study participants reported being interested in having pharmacists provide children's liquid medications in the proposed dosing device, and 40% were willing to pay for such a service. 90% of respondents reported it is "not at all difficult" to understand the amount of dose a child is to receive, while 55% reported it is "not at all difficult" to measure doses. 25% of respondents reported sometimes using a kitchen spoon to measure a child's medication. Conclusion: Community pharmacists should explore providing children's liquid medications in an individualized dosing device, as study results determined parents are interested in and willing to pay for the theoretical device. Further large-scale studies would be beneficial in determining interest in and willingness to pay for the dosing device in various pharmacy settings nationwide.   Type: Original Research

Genetic variants associated with warfarin dose in African-American individuals: a genome-wide association study

OpenAIRE

Perera, Minoli A; Cavallari, Larisa H; Limdi, Nita A; Gamazon, Eric R; Konkashbaev, Anuar; Daneshjou, Roxana; Pluzhnikov, Anna; Crawford, Dana C; Wang, Jelai; Liu, Nianjun; Tatonetti, Nicholas; Bourgeois, Stephane; Takahashi, Harumi; Bradford, Yukiko; Burkley, Benjamin M

2013-01-01

Summary BackgroundVKORC1 and CYP2C9 are important contributors to warfarin dose variability, but explain less variability for individuals of African descent than for those of European or Asian descent. We aimed to identify additional variants contributing to warfarin dose requirements in African Americans. MethodsWe did a genome-wide association study of discovery and replication cohorts. Samples from African-American adults (aged ≥18 years) who were taking a stable maintenance dose of warfar...

Individualized FSH dosing based on ovarian reserve testing in women starting IVF/ICSI: a multicentre trial and cost-effectiveness analysis

OpenAIRE

van Tilborg, Theodora C.; Oudshoorn, Simone C.; Eijkemans, Marinus J. C.; Mochtar, Monique H.; van Golde, Ron J. T.; Hoek, Annemieke; Kuchenbecker, Walter K. H.; Fleischer, Kathrin; de Bruin, Jan Peter; Groen, Henk; van Wely, Madelon; Lambalk, Cornelis B.; Laven, Joop S. E.; Mol, Ben Willem J.; Broekmans, Frank J. M.

2017-01-01

STUDY QUESTION: Is there a difference in live birth rate and/or cost-effectiveness between antral follicle count (AFC)-based individualized FSH dosing or standard FSH dosing in women starting IVF or ICSI treatment? SUMMARY ANSWER: In women initiating IVF/ICSI, AFC-based individualized FSH dosing does not improve live birth rates or reduce costs as compared to a standard FSH dose. WHAT IS KNOWN ALREADY: In IVF or ICSI, ovarian reserve testing is often used to adjust the FSH dose in order to no...

An Internal Dose Assessment Associated with Personal Food Intake

Energy Technology Data Exchange (ETDEWEB)

Lee, Joeun; Jae, Moosung [Hanyang University, Seoul (Korea, Republic of); Hwang, Wontae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

ICRP (International Commission on Radiological Protection), Therefore, had recommended the concept of 'Critical Group'. Recently the ICRP has recommended the use of 'Representative Person' on the new basic recommendation 103. On the other hand the U.S. NRC (Nuclear Regulatory Commission) has adopted more conservative concept, 'Maximum Exposed Individuals (MEI)' of critical Group. The dose assessment in Korea is based on MEI. Although dose assessment based on MEI is easy to receive the permission of the regulatory authority, it is not efficient. Meanwhile, the internal dose by food consumption takes an important part. Therefore, in this study, the internal dose assessment was performed in accordance with ICRP's new recommendations. The internal dose assessment was performed in accordance with ICRP's new recommendations. It showed 13.2% decreased of the annual internal dose due to gaseous effluents by replacing MEI to the concept of representative person. Also, this calculation based on new ICRP's recommendation has to be extended to all areas of individual dose assessment. Then, more accurate and efficient values might be obtained for dose assessment.

Individual and collective dose rates from naturally-occurring radionuclides in seafood

International Nuclear Information System (INIS)

Pentreath, R.J.; Camplin, W.C.; Allington, D.J.

1989-01-01

Although seafoods are not a large item in the UK diet, they are of interest because of the above-average quantities of naturally-occurring radionuclides which they contain -particularly shellfish. The single most important contributor is 210 Po; studies have therefore been made to examine the contribution which this nuclide makes to the dose received, both collectively and to individual high-rate consumers of shellfish. (author)

Individual dose due to radioactivity accidental release from fusion reactor

Energy Technology Data Exchange (ETDEWEB)

Nie, Baojie [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); University of Science and Technology of China, Hefei, Anhui, 230027 (China); Ni, Muyi, E-mail: muyi.ni@fds.org.cn [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); Wei, Shiping [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); University of Science and Technology of China, Hefei, Anhui, 230027 (China)

2017-04-05

Highlights: • Conservative early dose of different unit fusion radioactivity release were assessed. • Data of accident level in INES for fusion reactor were proposed. • Method of environmental restoration time after fusion accident was proposed. • The maximum possible accident level for ITER like fusion reactor is 6. • We need 34–52 years to live after the fusion hypothetical accident. - Abstract: As an important index shaping the design of fusion safety system, evaluation of public radiation consequences have risen as a hot topic on the way to develop fusion energy. In this work, the comprehensive public early dose was evaluated due to unit gram tritium (HT/HTO), activated dust, activated corrosion products (ACPs) and activated gases accidental release from ITER like fusion reactor. Meanwhile, considering that we cannot completely eliminate the occurrence likelihood of multi-failure of vacuum vessel and tokamak building, we conservatively evaluated the public radiation consequences and environment restoration after the worst hypothetical accident preliminarily. The comparison results show early dose of different unit radioactivity release under different conditions. After further performing the radiation consequences, we find it possible that the hypothetical accident for ITER like fusion reactor would result in a level 6 accident according to INES, not appear level 7 like Chernobyl or Fukushima accidents. And from the point of environment restoration, we need at least 69 years for case 1 (1 kg HTO and 1000 kg dust release) and 34–52 years for case 2 (1 kg HTO and 10kg–100 kg dust release) to wait the contaminated zone drop below the general public safety limit (1mSv per year) before it is suitable for human habitation.

Model-Based Individualized Treatment of Chemotherapeutics: Bayesian Population Modeling and Dose Optimization.

Directory of Open Access Journals (Sweden)

Devaraj Jayachandran

Full Text Available 6-Mercaptopurine (6-MP is one of the key drugs in the treatment of many pediatric cancers, auto immune diseases and inflammatory bowel disease. 6-MP is a prodrug, converted to an active metabolite 6-thioguanine nucleotide (6-TGN through enzymatic reaction involving thiopurine methyltransferase (TPMT. Pharmacogenomic variation observed in the TPMT enzyme produces a significant variation in drug response among the patient population. Despite 6-MP's widespread use and observed variation in treatment response, efforts at quantitative optimization of dose regimens for individual patients are limited. In addition, research efforts devoted on pharmacogenomics to predict clinical responses are proving far from ideal. In this work, we present a Bayesian population modeling approach to develop a pharmacological model for 6-MP metabolism in humans. In the face of scarcity of data in clinical settings, a global sensitivity analysis based model reduction approach is used to minimize the parameter space. For accurate estimation of sensitive parameters, robust optimal experimental design based on D-optimality criteria was exploited. With the patient-specific model, a model predictive control algorithm is used to optimize the dose scheduling with the objective of maintaining the 6-TGN concentration within its therapeutic window. More importantly, for the first time, we show how the incorporation of information from different levels of biological chain-of response (i.e. gene expression-enzyme phenotype-drug phenotype plays a critical role in determining the uncertainty in predicting therapeutic target. The model and the control approach can be utilized in the clinical setting to individualize 6-MP dosing based on the patient's ability to metabolize the drug instead of the traditional standard-dose-for-all approach.

Model-Based Individualized Treatment of Chemotherapeutics: Bayesian Population Modeling and Dose Optimization

Science.gov (United States)

Jayachandran, Devaraj; Laínez-Aguirre, José; Rundell, Ann; Vik, Terry; Hannemann, Robert; Reklaitis, Gintaras; Ramkrishna, Doraiswami

2015-01-01

6-Mercaptopurine (6-MP) is one of the key drugs in the treatment of many pediatric cancers, auto immune diseases and inflammatory bowel disease. 6-MP is a prodrug, converted to an active metabolite 6-thioguanine nucleotide (6-TGN) through enzymatic reaction involving thiopurine methyltransferase (TPMT). Pharmacogenomic variation observed in the TPMT enzyme produces a significant variation in drug response among the patient population. Despite 6-MP’s widespread use and observed variation in treatment response, efforts at quantitative optimization of dose regimens for individual patients are limited. In addition, research efforts devoted on pharmacogenomics to predict clinical responses are proving far from ideal. In this work, we present a Bayesian population modeling approach to develop a pharmacological model for 6-MP metabolism in humans. In the face of scarcity of data in clinical settings, a global sensitivity analysis based model reduction approach is used to minimize the parameter space. For accurate estimation of sensitive parameters, robust optimal experimental design based on D-optimality criteria was exploited. With the patient-specific model, a model predictive control algorithm is used to optimize the dose scheduling with the objective of maintaining the 6-TGN concentration within its therapeutic window. More importantly, for the first time, we show how the incorporation of information from different levels of biological chain-of response (i.e. gene expression-enzyme phenotype-drug phenotype) plays a critical role in determining the uncertainty in predicting therapeutic target. The model and the control approach can be utilized in the clinical setting to individualize 6-MP dosing based on the patient’s ability to metabolize the drug instead of the traditional standard-dose-for-all approach. PMID:26226448

Uncertainties in estimating heart doses from 2D-tangential breast cancer radiotherapy

DEFF Research Database (Denmark)

Laugaard Lorenzen, Ebbe; Brink, Carsten; Taylor, Carolyn W.

2016-01-01

BACKGROUND AND PURPOSE: We evaluated the accuracy of three methods of estimating radiation dose to the heart from two-dimensional tangential radiotherapy for breast cancer, as used in Denmark during 1982-2002. MATERIAL AND METHODS: Three tangential radiotherapy regimens were reconstructed using CT......-based planning scans for 40 patients with left-sided and 10 with right-sided breast cancer. Setup errors and organ motion were simulated using estimated uncertainties. For left-sided patients, mean heart dose was related to maximum heart distance in the medial field. RESULTS: For left-sided breast cancer, mean...... to the uncertainty of estimates based on individual CT-scans. For right-sided breast cancer patients, mean heart dose based on individual CT-scans was always

Controllable dose: a discussion on the control of individual doses from single sources

International Nuclear Information System (INIS)

Clarke, R.H.

1999-01-01

Contaminated land is an issue of considerable interest in many countries. It arises as a result of accidental releases, as from Chernobyl, and from manmade activities including atmospheric testing of nuclear weapons. Contamination is also an historic liability from, for example, plants using radium, or from excessive effluent discharges. A particular issue at present is the decommissioning of nuclear facilities, old reactors and weapons fabrication facilities. These liabilities require the expenditure of considerable amounts of money and some people think that too much money is being, and will be, spent to achieve low levels of residual contamination. If contaminated land is not cleaned up there is public concern and in some countries there will be litigation, charging that the environmental risk is too great. These concerns have led to an increased pressure from some individuals to propose a threshold in the dose-response relationship in order to reduce the expenditure. It is true that, increasingly, our science is judged in the courts rather than by national academies os science. Judge and jury will decide on the issue of the threshold and it is they who must be convinced as to whether there are no risks at low doses of radiation. The issue is primarily in relation to public non occupational exposure, and because of the continuing lack of definitive scientific evidence, a new approach to protection could be considered (author)

Controllable dose: a discussion on the control of individual doses from single sources

International Nuclear Information System (INIS)

Clarke, R.

1999-01-01

Contaminated land is an issue of considerable interest in many countries. It arises as a result of accidental releases, as from Chernobyl, and from manmade activities including atmospheric testing of nuclear weapons. Contamination is also an historic liability from, for example, plants using radium, or from excessive effluent discharges. A particular issue at present is the decommissioning of nuclear facilities, old reactors and weapons fabrication facilities. These liabilities require the expenditure of considerable amounts of money and some people think that too much money is being, and will be, spent to achieve low levels of residual contamination. If contaminated land is not cleaned up these is public concern and in some countries there will be litigation, charging that the environmental risk is too great. These concerns have led to an increased pressure from some individuals to propose a threshold in the dose-responses relationship in order to reduce the expenditure. It is true that, increasingly, our science is judged in the courts rather by national academies of sciences. Judge and jury decide on the issue to the threshold and it is they who must convinced as to whether there are no risks at low doses of radiation. The issue is primarily in relation to public not occupational exposure, and because of the continuing lack of definitive scientific evidence, a new approach to protection could be considered. (author)

Assessment of the individual thyroid dose for the cohort members of the Belarusian-American epidemiological study

International Nuclear Information System (INIS)

Minenko, Victor; Kuchta, Tatyana; Khrutchinsky, Arkady; Kutsen, Semion; Bouville, Andre; Drozdovitch, Vladimir; Luckyanov, Nickolas; Shinkarev, Sergey; Gavrilin, Yury; Khrouch, Valeri

2008-01-01

Full text: The U.S. National Cancer Institute and the Ministry of Health of Belarus conduct jointly an epidemiological study of thyroid cancer and other thyroid diseases in a cohort of 12,000 Belarusian subjects aged up to 18 years at the time of the Chernobyl accident in 1986. One of the important aspects of the study is the reconstruction of individual doses for all cohort members. Reconstruction of thyroid doses is based on the measurements of 131 I content in the thyroid glands of the subjects, which were performed in May-June 1986. In addition, the following information elicited by the personal interview is used to evaluate individual 131 I intake function for each cohort member: residential history; consumption rates of milk, dairy products and leafy vegetables and origin of consumed foodstuffs; and individual countermeasures undertaken shortly after the accident. The second round of thyroid doses estimation, which is currently conducted, includes Monte Carlo calculations of the age-dependent conversion coefficients from the measuring devices reading to the 131 I activity in the thyroid; estimation of the influence of surface contamination and internal body-burden on the exposure rate measured near the thyroid; and validation of parameters of the radioecological model used to assess the 131 I intake function. The revised thyroid dose estimates and their uncertainties will be presented, and the results obtained will be compared with the previous set of thyroid dose estimates. (author)

Individualized toxicity-titrated 6-mercaptopurine increments during high-dose methotrexate consolidation treatment of lower risk childhood acute lymphoblastic leukemia

DEFF Research Database (Denmark)

Frandsen, Thomas Leth; Abrahamsson, Jonas; Lausen, Birgitte Frederiksen

2011-01-01

This study explored the feasibility and toxicity of individualized toxicity-titrated 6-mercaptopurine (6MP) dose increments during post-remission treatment with High-dose methotrexate (HDM) (5000 mg/m2, ×3) in 38 patients with Childhood (ALL). Patients were increased in steps of 25 mg 6MP/m2 per...... the remaining patients (P = 0·03). This study shows individualized toxicity-titrated 6MP dosing during consolidation is feasible without increased risk of toxicity....

Direct measurement of a patient's entrance skin dose during pediatric cardiac catheterization

International Nuclear Information System (INIS)

Sun, Lue; Mizuno, Yusuke; Goto, Takahisa; Iwamoto, Mari; Koguchi, Yasuhiro; Miyamoto, Yuka; Tsuboi, Koji; Chida, Koichi; Moritake, Takashi

2014-01-01

Children with complex congenital heart diseases often require repeated cardiac catheterization; however, children are more radiosensitive than adults. Therefore, radiation-induced carcinogenesis is an important consideration for children who undergo those procedures. We measured entrance skin doses (ESDs) using radio-photoluminescence dosimeter (RPLD) chips during cardiac catheterization for 15 pediatric patients (median age, 1.92 years; males, n = 9; females, n = 6) with cardiac diseases. Four RPLD chips were placed on the patient's posterior and right side of the chest. Correlations between maximum ESD and dose-area products (DAP), total number of frames, total fluoroscopic time, number of cine runs, cumulative dose at the interventional reference point (IRP), body weight, chest thickness, and height were analyzed. The maximum ESD was 80 ± 59 (mean ± standard deviation) mGy. Maximum ESD closely correlated with both DAP (r = 0.78) and cumulative dose at the IRP (r = 0.82). Maximum ESD for coiling and ballooning tended to be higher than that for ablation, balloon atrial septostomy, and diagnostic procedures. In conclusion, we directly measured ESD using RPLD chips and found that maximum ESD could be estimated in real-time using angiographic parameters, such as DAP and cumulative dose at the IRP. Children requiring repeated catheterizations would be exposed to high radiation levels throughout their lives, although treatment influences radiation dose. Therefore, the radiation dose associated with individual cardiac catheterizations should be analyzed, and the effects of radiation throughout the lives of such patients should be followed. (author)

The individual tolerance concept is not the sole explanation for the probit dose-effect model

Energy Technology Data Exchange (ETDEWEB)

Newman, M.C.; McCloskey, J.T.

2000-02-01

Predominant methods for analyzing dose- or concentration-effect data (i.e., probit analysis) are based on the concept of individual tolerance or individual effective dose (IED, the smallest characteristic dose needed to kill an individual). An alternative explanation (stochasticity hypothesis) is that individuals do not have unique tolerances: death results from stochastic processes occurring similarly in all individuals. These opposing hypotheses were tested with two types of experiments. First, time to stupefaction (TTS) was measured for zebra fish (Brachydanio rerio) exposed to benzocaine. The same 40 fish were exposed during five trials to test if the same order for TTS was maintained among trials. The IED hypothesis was supported with a minor stochastic component being present. Second, eastern mosquitofish (Gambusia holbrooki) were exposed to sublethal or lethal NaCl concentrations until a large portion of the lethally exposed fish died. After sufficient time for recovery, fish sublethally exposed and fish surviving lethal exposure were exposed simultaneously to lethal NaCl concentrations. No statistically significant effect was found of previous exposure on survival time but a large stochastic component to the survival dynamics was obvious. Repetition of this second type of test with pentachlorophenol also provided no support for the IED hypothesis. The authors conclude that neither hypothesis alone was the sole or dominant explanation for the lognormal (probit) model. Determination of the correct explanation (IED or stochastic) or the relative contributions of each is crucial to predicting consequences to populations after repeated or chronic exposures to any particular toxicant.

Dose-effect relationship in production of dicentrics and rings in blood lymphocytes of individuals living in high background radiation area

International Nuclear Information System (INIS)

Jiang Tao; Hayata, I.; Wang Cunyan

1999-01-01

Objective: To explore the dose-effect relationship in the production of chromosome aberrations by high background radiation by using statistically appropriate individual measurements. Methods: Chromosome analysis was performed in separated blood lymphocytes of 39 family members of different ages from either high background radiation area (HBRA) or control area (CA). Individual cumulative doses ranged from 23.9-261.3 and 5.2-29.8 mGy for HBRA and CA, respectively. A total of about 100,000 cells were scored and dicentric and ring chromosome (dic + Rc) aberrations recorded. Results: In the case of HBRA, individual chromosome aberration frequencies increased with age within each family. The increasing trend was in general not significantly different among families. The increase in individual aberration was closely correlated with age and cumulative dose. Age-and dose-effect relationship fit well the linear equation: Y = 0.0448X + 0.4913 (R 2 = 0.7814) for age and Y 0.0156X + 0.5715 (R 2 = 0.7061) for cumulative dose, respectively. In the case of CA, there was no significant difference in aberration yields among individuals of different ages, and the group mean aberration frequency was 1.24 +- 0.69 x 10 -3 . Conclusions: Dic and Rc can continuously accumulate over a lifetime chronic low dose exposures, and can serve as a reliable biological indicator. However, the ultimate sensitivity is about 50 mGy

The choice of individual dose criterion at which to restrict agricultural produce following an unplanned release of radioactive material to atmosphere

International Nuclear Information System (INIS)

Dionian, J.; Simmonds, J.R.

1985-06-01

In the event of an accidental release of radioactive material to atmosphere, the introduction of emergency countermeasures will be based on the need to limit the risk to individuals. However, it has been suggested that a form of cost-benefit analysis may be used as an input to decisions on the withdrawal of countermeasures, although it is recognised that these decisions may be influenced by factors other than those directly related to radiological protection. In this study, a method based on cost-benefit analysis is illustrated for assessing the optimum level of individual dose at which restrictions on agricultural production may be considered. This requires monetary values to be assigned to both the lost food production and to the health detriment, expressed as the collective effective dose equivalent commitment. It has been assumed in this analysis that food-supply restrictions are both introduced and withdrawn at the same projected level of annual individual dose. The effect on the optimum dose level of the following parameters is examined: the type of produce restricted; the size of the release; the site and direction of the release; the weather conditions; and the cost assigned to unit collective dose. It is shown that the optimum dose criterion, based on the effective dose equivalent received by an individual from a years intake of food, varies over practically the whole range of individual dose considered, i.e., 0.1 to 50 mSv. However, it is concluded that 5 mSv would represent the optimum dose criterion in a substantial number of cases. (author)

Approach to calculating upper bounds on maximum individual doses from the use of contaminated well water following a WIPP repository breach. Report EEG-9

International Nuclear Information System (INIS)

Spiegler, P.

1981-09-01

As part of the assessment of the potential radiological consequences of the proposed Waste Isolation Pilot Plant (WIPP), this report evaluates the post-closure radiation dose commitments associated with a possible breach event which involves dissolution of the repository by groundwaters and subsequent transport of the nuclear waste through an aquifer to a well assumed to exist at a point 3 miles downstream from the repository. The concentrations of uranium and plutonium isotopes at the well are based on the nuclear waste inventory presently proposed for WIPP and basic assumptions concerning the transport of waste as well as treatment to reduce the salinity of the water. The concentrations of U-233, Pu-239, and Pu-240, all radionuclides originally emplaced as waste in the repository, would exceed current EPA drinking water limits. The concentrations of U-234, U-235, and U-236, all decay products of plutonium isotopes originally emplaced as waste, would be well below current EPA drinking water limits. The 50-year dose commitments from one year of drinking treated water contaminated with U-233 or Pu-239 and Pu-240 were found to be comparable to a one-year dose from natural background. The 50-year dose commitments from one year of drinking milk would be no more than about 1/5 the dose obtained from ingestion of treated water. These doses are considered upper bounds because of several very conservative assumptions which are discussed in the report

Efficiency analysis of using tailored individual doses of radioiodine and fine tuning using a low-dose antithyroid drug in the treatment of Graves' disease.

Science.gov (United States)

Liu, Chang-Jiang; Dong, Yan-Yu; Wang, Yi-Wei; Wang, Kai-Hua; Zeng, Qun-Yan

2011-03-01

To evaluate the effect of using tailored individual doses of radioiodine (¹³¹I) and fine tuning using low-dose antithyroid drug (ATD) in the treatment of Graves' disease, and an attempt to establish a therapeutic strategy that can keep both high rate of euthyroidism and low incidence of hypothyroidism. The dose of radioiodine was calculated using the calculated dose formula, and low-dose ATD was used as a way of fine tuning during follow-up. The intended dose of radioiodine was modified according to the patient's age at radioiodine therapy, thyroid size, and duration of hyperthyroidism before radioiodine therapy in the study group; it was set as 2.96 MBq/g of thyroid in the control group. Twenty patients with Graves' disease were nonrandomly assigned to the control group and 98 patients with Graves' disease to the study group. The outcomes, which included euthyroidism, hypothyroidism, and persistent hyperthyroidism, were determined according to the patients' states at the end of follow-up. In the study group, 74 patients (75.5%) achieved the euthyroid state, six patients (6.1%) became hypothyroid, and 18 patients (18.4%) remained hyperthyroid. The rate of euthyroidism was statistically different between the study group and the control group (75.5 vs. 50%, P=0.03). Of 98 patients with Graves' disease in the study group, 19 patients were additionally treated with ATD during follow-up, and 12 patients achieved euthyroidism. In different age groups or duration of hyperthyroidism groups, the rate of euthyroidism was not statistically different among subgroups of goiter grade 1, grade 2, and grade 3 (P>0.05). Similarly, in different age groups or duration of hyperthyroidism groups, the incidence of hypothyroidism was not statistically different among subgroups of goiter grade 1, grade 2, and grade 3 (P>0.05). However, binary logistic regression analysis showed that thyroid size was associated with overtreatment and undertreatment in our study. Individual doses of

6LiF sandwich type detectors for low dose individual monitoring in mixed neutron-photon fields

International Nuclear Information System (INIS)

Olko, P.; Budzanowski, M.; Bilski, P.; Burgkhardt, B.; Piesch, E.

1994-01-01

ICRP Publication 60 recommends the reduction of the annual dose limit for occupational exposure from 50 to 20 mSv and a doubling of the quality factor for medium energy neutrons. If occupational doses are evaluated every month (which is obligatory e.g. in Germany and in Poland), the individual neutron dosemeter will have to measure neutron doses in the range of 100 μSv. No commercially available, automatic individual dosimetry monitoring system exists that fulfils this requirement. Some of the parameters which influence the evaluation of the neutron dose from readings of TL dosemeters have been studied in order to decrease the variance of the measured neutron signal. In mixed neutron-photon fields, clear separation of the neutron component from the total reading depends also on the uncertainty of the gamma dose measurements. While the thermal albedo neutrons are absorbed mostly at the surface of the 6 LiF detector, the reduction of the detector thickness results in a decrease of its photon sensitivity, while its neutron sensitivity is almost principally maintained. As a consequence, the uncertainty of gamma dose contributes with lower weight to the variance of the evaluated neutron signal. First tests of an optimised 200 μm thick sandwich detector and 0.9 mm thick standard LiF chips were made at low neutron and photon dose ranges using different readers, in order to determine the uncertainty versus dose for different neutron-photon combinations. The conditions under which the new sandwich type detectors may improve albedo neutron dosimetry are demonstrated. (Author)

Annual individual hygienic assessment of natural exposure doses of the Altai territory model areas population

Directory of Open Access Journals (Sweden)

N. Yu. Potseluev

2016-01-01

Full Text Available The goal is to determine ionizing radiation natural sources exposure regularities of Altai Territory model areas population. The materials and methods. 11376 radon measurements, 1247 gamma radiation meas-urements in an open area and in residential and office buildings were performed, selection of 189 drinking water tests was carried out. Results. Complex radiation and hygienic examination of the region with the most large municipalities number with model areas allocation was conducted. The assessment of the Altai Territory population’s individual annual radiation doses from natural radionuclides has revealed a number of the regularities depending on the terrain’s ecological and geographical type. Following the research results, ranging the region territories taking into account of annual effective doses of the population from natural sources for 2009-2015 was carried out. The annual individual effective dose of the Altai Territory upland areas population presented by the highest values and ranges from 7.36 mSv / year to 8.19 mSv / year. Foothill regions of Altai and in Salair ridge are characterized by increased population exposure from natural sources. Here the dose ranges from 5.09 mSv / year to 6.22 mSv / year. Steppe and forest-steppe territories are characterized by the lowest level of the natural radiation which is ranging from 3.23 mSv / year to 4.11 mSv / year, that doesn’t exceed the all-Russian levels. Most of the hygienic radon equivalent equilibrium volume activity standards exceedances were registered in mountain and foothill areas buildings. A number of radon anomalies is revealed also in steppe areas. Med exceedances ranged from 203 ± 17.8 Bq / m3 to 480 ± 37.9 Bq / m3. Given the fact that most of these buildings belong to the administrative or educational institutions with an eight-hour working day, the dose of radiation for people there can be up to 10 mSv / year. Conclusion. Spreading of individual annual effective

Reliability of individual doses relating to the epidemiological studies on nuclear industry workers in Japan (1). Historical changes on definition of radiation dose, historical changes on technical standards of measurement and radiation workplace

International Nuclear Information System (INIS)

Numakunai, Takao; Ishiguro, Hideharu; Kawada, Yasushi; Minami, Kentaro; Yoshimoto, Yasuhiko.

1997-01-01

Records of radiation workers collected in the Research Organization for Information of Science and Technology, concerning individual doses from 1957 to 1992 were used for epidemiological studies for obtaining the scientific information of the effect of low dose radiation. Since many changes were made on definition of radiation dose, dosimetry technology and so on during such a long time period, reliability of recorded individual doses and of their measurement should be evaluated for validation, which is the purpose of this paper. Followings were discussed and validation was made. Historical changes on standards for radiation protection: ICRP Recommendation and ICRU Report, and changes of law concerning radiation dose in Japan and of dose standards. Changes on dosimetry for radiation protection: ICRP Recommendation and working place dosimetry, trends of investigations for introduction of measured practical doses, ICRU sphere as a receptor, and introduction of measured practical doses. Characteristics of radiation field and radiation exposure: Radiation source and characteristics of radiation field; Research and development organizations for atomic power, atomic power plants, facilities for nuclear fuel, Classification of radiation works and characteristics of the exposure; BWR, PWR, GCR. Changes on the standards of individual dosemeter and on its use: method to use individual dosemeter and its installation, measurement of individual dose and Japanese Industrial Standard (JIS); Standard of the film badge for X and gamma rays, Standard of the film badge for neutron, Standard for thermoluminescence dosemeter, and changes on selection of the major apparatus and on its use. (K.H.)

Maximum likelihood as a common computational framework in tomotherapy

International Nuclear Information System (INIS)

Olivera, G.H.; Shepard, D.M.; Reckwerdt, P.J.; Ruchala, K.; Zachman, J.; Fitchard, E.E.; Mackie, T.R.

1998-01-01

Tomotherapy is a dose delivery technique using helical or axial intensity modulated beams. One of the strengths of the tomotherapy concept is that it can incorporate a number of processes into a single piece of equipment. These processes include treatment optimization planning, dose reconstruction and kilovoltage/megavoltage image reconstruction. A common computational technique that could be used for all of these processes would be very appealing. The maximum likelihood estimator, originally developed for emission tomography, can serve as a useful tool in imaging and radiotherapy. We believe that this approach can play an important role in the processes of optimization planning, dose reconstruction and kilovoltage and/or megavoltage image reconstruction. These processes involve computations that require comparable physical methods. They are also based on equivalent assumptions, and they have similar mathematical solutions. As a result, the maximum likelihood approach is able to provide a common framework for all three of these computational problems. We will demonstrate how maximum likelihood methods can be applied to optimization planning, dose reconstruction and megavoltage image reconstruction in tomotherapy. Results for planning optimization, dose reconstruction and megavoltage image reconstruction will be presented. Strengths and weaknesses of the methodology are analysed. Future directions for this work are also suggested. (author)

Population dose commitments due to radioactive releases from nuclear power plant sites in 1987

International Nuclear Information System (INIS)

Baker, D.A.

1990-08-01

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1987. Fifty-year dose commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 70 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for reach of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The site average individual dose commitment from all pathways ranged from a low of 2 x 10 -6 mrem to a high of 0.009 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. However, licensee calculation of doses to the maximally exposed individual at some sites indicated values of up to approximately 100 times average individual doses (on the order of a few millirem per year). 2 refs., 2 figs., 7 tabs

Genetically significant dose assessments of occupationally exposed individuals involved in industrial and medical radiographic procedures in certain establishments in Nigeria

International Nuclear Information System (INIS)

Jibiri, N.N.; Oguntade, G. T.

2007-01-01

The main source of radiation doses received by humans from man-made sources of ionizing radiation in medicine and industry comes from X-rays. The genetic risks of ionizing radiation effects on an individual who is occupationally exposed largely depend on the magnitude of the radiation dose received, period of practice, work load and radio logical procedures involved. In this work, using the linear non-thresh old model, we have attempted to assess the level of genetic risk of occupationally exposed individuals in two medical and industrial establishments in Nigeria by estimating their genetically significant dose values. The estimation was based on continuous personnel radiation dose monitoring data for the individuals in each of the establishments over a three year period (1998-2001). The estimated genetically significant dose values in the years considered were 12 mSv for the medical, and 29 mSv for the industrial personnel. Appropriate radiation protection precautions should be taken by the personnel to adhere to standard operational practices in order to minimize the genetically significant dose resulting from radio logical practices

Individualized Dosing of Children’s Liquid Medications in the Community Pharmacy Setting: A Survey of Parents and Guardians

Directory of Open Access Journals (Sweden)

Lingxiao Zhai, MS

2013-01-01

Full Text Available Objectives: 1 To determine parents’ and/or guardians’ interest in having pharmacists provide children’s liquid medications in a pre-measured, individualized dosing device 2 To assess parents’ and/or guardians’ perception of dosing liquid medications for a child. Design: Observational survey Setting: Regional chain pharmacy in North Carolina Participants: > 18 years old, parent/guardian of a child <13 who had prescription filled for liquid medication within the pharmacy chain, responsible for administering child’s liquid medication Intervention: 14 item questionnaire Main Outcome Measure: Interest in pharmacists providing children’s liquid medications in pre-measured, individualized dosing devices Results: 250 questionnaires were mailed; 42 were marked “return to sender” (16.8%, 22 were returned completed (10.6%, and 20 of the 22 met inclusion criteria (9.6%. 95% of study participants reported being interested in having pharmacists provide children’s liquid medications in the proposed dosing device, and 40% were willing to pay for such a service. 90% of respondents reported it is “not at all difficult” to understand the amount of dose a child is to receive, while 55% reported it is “not at all difficult” to measure doses. 25% of respondents reported sometimes using a kitchen spoon to measure a child’s medication. Conclusion: Community pharmacists should explore providing children’s liquid medications in an individualized dosing device, as study results determined parents are interested in and willing to pay for the theoretical device. Further large-scale studies would be beneficial in determining interest in and willingness to pay for the dosing device in various pharmacy settings nationwide.

Skin dose variation: influence of energy

International Nuclear Information System (INIS)

Cheung, T.; Yu, P.K.N.; Butson, M.J.; Cancer Services, Wollongong, NSW

2004-01-01

Full text: This research aimed to quantitatively evaluate the differences in percentage dose of maximum for 6MV and 18MV x-ray beams within the first lcm of interactions. Thus provide quantitative information regarding the basal, dermal and subcutaneous dose differences achievable with these two types of high-energy x-ray beams. Percentage dose of maximum build up curves are measured for most clinical field sizes using 6MV and 18MV x-ray beams. Calculations are performed to produce quantitative results highlighting the percentage dose of maximum differences delivered to various depths within the skin and subcutaneous tissue region by these two beams Results have shown that basal cell layer doses are not significantly different for 6MV and 18Mv x-ray beams At depths beyond the surface and basal cell layer there is a measurable and significant difference in delivered dose. This variation increases to 20% of maximum and 22% of maximum at Imm and 1cm depths respectively. The percentage variations are larger for smaller field sizes where the photon in phantom component of the delivered dose is the most significant contributor to dose By producing graphs or tables of % dose differences in the build up region we can provide quantitative information to the oncologist for consideration (if skin and subcutaneous tissue doses are of importance) during the beam energy selection process for treatment. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

Individual radiation doses. Annual report 1995

International Nuclear Information System (INIS)

Bergman, L.

1995-05-01

During the year we measured whole body doses on 10226 bearers, distributed as follows: 0-0,5 mSv on 8816 persons, 0,6-1,0 mSv on 693 persons, 1,1-5,0 on 678 persons, >5 mSv on 39 persons. At higher dose than 4 mSv/4 weeks, the reason to the irradiation will be investigated. 2 figs, 2 tabs

Development of a kinetic model and calculation of radiation dose estimates for sodium iodide-131I in athyroid individuals

International Nuclear Information System (INIS)

Rodriguez, M.

1997-07-01

The treatment for some thyroid carcinomas involves surgically removing the thyroid gland and administering the radiopharmaceutical Sodium iodide- 131 I (NaI). A diagnostic dose of NaI is given to the patient to determine if remnant tissue from the gland remains or larger doses are administered in order to treat the malignant tissue. Past research regarding NaI uptake and retention in euthyroid individuals (normal functioning thyroid) reveal that radioiodine concentrates mainly in the thyroid tissue and the remaining material is excreted from the body. The majority of radioiodine in athyroid (without thyroid) individuals is also eliminated from the body; however, there has been recent evidence of a long-term retention phase for individuals with no radioiodine concentrating tissue. The general purpose of this study was to develop a kinetic model and estimate the absorbed dose to athyroid individuals regarding the distribution and retention of NaI

Dose-effect relationships for individual pelvic floor muscles and anorectal complaints after prostate radiotherapy.

NARCIS (Netherlands)

Smeenk, R.J.; Hoffmann, A.L.; Hopman, W.P.M.; Lin, E.N.J.T. van; Kaanders, J.H.A.M.

2012-01-01

PURPOSE: To delineate the individual pelvic floor muscles considered to be involved in anorectal toxicity and to investigate dose-effect relationships for fecal incontinence-related complaints after prostate radiotherapy (RT). METHODS AND MATERIALS: In 48 patients treated for localized prostate

A study on the food consumption rates for off-site radiological dose assessment around Korean Nuclear Power Plants

International Nuclear Information System (INIS)

Lee, Gab Bock; Chung, Yang Geun

2008-01-01

The internal dose by food consumption mostly accounts for radiological dose of public around Nuclear Power Plants (NPPs). But, food consumption rates applied to off-site dose calculation in Korea which are the result of field investigation around Kori NPP by the KAERI (Korea Atomic Energy Research Institute) in 1988, are not able to reflect the latest dietary characteristics of Korean. The food consumption rates to be used for radiological dose assessment in Korea are based on the maximum individual of US NRC (Nuclear Regulatory Commission) Regulatory Guide 1.109. However, the representative individual of the critical group is considered in the recent ICRP (International Commission on Radiological Protection) recommendation and European nations' practice. Therefore, the study on the re-establishment of the food consumption rates for individual around nuclear power plant sites in Korea was carried out to reflect on the recent change of the Korean dietary characteristics and to apply the representative individual of critical group to domestic regulations. The ministry of Health and Welfare Affairs has investigated the food and nutrition of nations every 3 years based on the Law of National Health Improvement. The statistical data such as mean, standard deviation, various percentile values about food consumption rates to be used for the representative individual of the critical group were analyzed by using the raw data of the national food consumption survey in 2001∼2002. Also, the food consumption rates for maximum individual are re-estimated

Measurements of individual doses from external radiation in the Brjansk region of the Russian republic of the USSR

International Nuclear Information System (INIS)

Wallstroem, E.; Woehni, T.

1991-01-01

Individual doses from external photon radiation to various occupational groups in three different villages in the Brjansk region of the Russian republic of the USSR have been measured by individual TL-dosemeters. A total of 86 persons were monitored for a period of 10 days in September 1990, from which 83 dosemeters were returned. The villages had different levels of deposition, but they all belonged to the ''strictly controlled zone'', i.e. deposition levels 555 to 1480 kBq/m 2 (15 to 40 Ci/km 2 ). The results show individual effective dose equivalents during one month in the range 80 to 1000 μSv. Schoolchildren received the lowest doses, and different groups of fields workers the highest. Estimated mean annual effective dose equivalents ranged from 2.0 mSv to 4.6 mSv for the different occupational groups and types of dwellings. Monthly mean effective dose equivalents relative to the reported mean deposition of Cs-137 ranged from 110 (in-door workers in stone houses) to 290 μSv per MBq/m 2 (out-door workers in wooden houses). The reported results are lower than theorectical estimates based on the reported level on contamination. The ratio of the mean effective dose equivalent for persons living in wooden and stone houses ranged from 1.4 to 2.6 for the various villages and occupational groups. 21 refs., 5 figs., 9 tabs

Biosphere Dose Conversion Factors for Reasonably Maximally Exposed Individual and Average Member of Critical Group

International Nuclear Information System (INIS)

K. Montague

2000-01-01

The purpose of this calculation is to develop additional Biosphere Dose Conversion Factors (BDCFs) for a reasonably maximally exposed individual (RMEI) for the periods 10,000 years and 1,000,000 years after the repository closure. In addition, Biosphere Dose Conversion Factors for the average member of a critical group are calculated for those additional radionuclides postulated to reach the environment during the period after 10,000 years and up to 1,000,000 years. After the permanent closure of the repository, the engineered systems within the repository will eventually lose their abilities to contain radionuclide inventory, and the radionuclides will migrate through the geosphere and eventually enter the local water table moving toward inhabited areas. The primary release scenario is a groundwater well used for drinking water supply and irrigation, and this calculation takes these postulated releases and follows them through various pathways until they result in a dose to either a member of critical group or a reasonably maximally exposed individual. The pathways considered in this calculation include inhalation, ingestion, and direct exposure

Patch test concentrations (doses in mg/cm2 ) for the 12 non-mix fragrance substances regulated by European legislation.

Science.gov (United States)

Bruze, Magnus; Svedman, Cecilia; Andersen, Klaus Ejner; Bruynzeel, Derk; Goossens, An; Johansen, Jeanne Duus; Matura, Mihaly; Orton, David; Vigan, Martine

2012-03-01

According to EU legislation, 26 fragrance substance allergens must be labelled on cosmetic products. For 12 of them, the optimal patch test concentration/dose has not been evaluated. To establish the optimal patch test doses in mg/cm2 for the 12 fragrance substances that are not included in fragrance mix I or II in the European baseline patch test series. Patch testing with the 12 fragrance substances was performed in a stepwise manner encompassing up to five rounds in at least 100 dermatitis patients for each round. Before patch testing, an individual maximum concentration/dose was determined for each fragrance substance. The predetermined maximum patch test concentrations/doses could be tested for all 12 fragrance substances, with no observable adverse reactions being noted. For each fragrance substance investigated, it is recommended that half of the maximum patch test dose (mg/cm2) be used for aimed and screening patch testing. © 2012 John Wiley & Sons A/S.

Nonlinearity and thresholds in dose-response relationships for carcinogenicity due to sampling variation, logarithmic dose scaling, or small differences in individual susceptibility

International Nuclear Information System (INIS)

Lutz, W.K.; Gaylor, D.W.; Conolly, R.B.; Lutz, R.W.

2005-01-01

Nonlinear and threshold-like shapes of dose-response curves are often observed in tests for carcinogenicity. Here, we present three examples where an apparent threshold is spurious and can be misleading for low dose extrapolation and human cancer risk assessment. Case 1: For experiments that are not replicated, such as rodent bioassays for carcinogenicity, random variation can lead to misinterpretation of the result. This situation was simulated by 20 random binomial samplings of 50 animals per group, assuming a true linear dose response from 5% to 25% tumor incidence at arbitrary dose levels 0, 0.5, 1, 2, and 4. Linearity was suggested only by 8 of the 20 simulations. Four simulations did not reveal the carcinogenicity at all. Three exhibited thresholds, two showed a nonmonotonic behavior with a decrease at low dose, followed by a significant increase at high dose ('hormesis'). Case 2: Logarithmic representation of the dose axis transforms a straight line into a sublinear (up-bent) curve, which can be misinterpreted to indicate a threshold. This is most pronounced if the dose scale includes a wide low dose range. Linear regression of net tumor incidences and intersection with the dose axis results in an apparent threshold, even with an underlying true linear dose-incidence relationship. Case 3: Nonlinear shapes of dose-cancer incidence curves are rarely seen with epidemiological data in humans. The discrepancy to data in rodents may in part be explained by a wider span of individual susceptibilities for tumor induction in humans due to more diverse genetic background and modulation by co-carcinogenic lifestyle factors. Linear extrapolation of a human cancer risk could therefore be appropriate even if animal bioassays show nonlinearity

Occupational dose trends in Tanzania

International Nuclear Information System (INIS)

Muhogora, W.E.; Nyanda, A.M.; Ngaile, J.E.; Lema, U.S.

1998-01-01

This paper describes the present status of occupational radiation exposure of monitored workers in Tanzania from 1986 to 1997. The analysis of dose records observes over this period, a fluctuating trend both in the individual and collective doses. The trend is more related to the fluctuations of the number of radiation workers than to the possible radiation safety changes of the working conditions. It has been found that, the maximum annual dose for the worker in all work categories was about 18 mSv y -1 . This suggests that the occupational radiation exposure in all practices satisfies the current dose limitation system. The national exposure summary shows that, the highest collective dose of 12.8 man-Sv which is 90% of the total collective dose, was due to medical applications. The applications in industry and research had a contribution of nearly 0.8 and 0.7 man-Sv respectively. From the professional point of view, the medical diagnostic radiographers received the highest collective dose of 11.2 man-Sv. Although the medical physicists recorded the minimum collective dose of nearly 0.07 man-Sv, the data shows that this profession received the highest mean dose of about 33 mSv in 12 years. Some achievements of the personnel monitoring services and suggestions for future improvement are pointed out. (author)

Methodical approach to reconstruct individual internal doses for persons residing in areas of Belarus contaminated as a result of the Chernobyl accident

International Nuclear Information System (INIS)

Skryabin, Anatoly; Belsky, Yuri

2008-01-01

Full text: The studies on the risk to population of low-level exposure following the Chernobyl accident require the estimation of the individual doses. The most difficult aspect is the estimation of internal exposure (IAED int ). Level of individual internal exposure due to ingestion of long-lived caesium isotopes defines by individual 'food habits' (IFH) of the person. Non-standard methodical approach is suggested to evaluate internal doses taking into IFH: 1) IFH are generally conservative by food characteristic and steady in time; 2) IFH of the person determines his dose which can be calculated using data of personal interview and the special table of conformity establishing connection between IFH and corresponding percentile interval in a variation line of doses in given settlement; 3) IAED int (1986-2005) is calculated as the sum of annual doses of the individual for all period of exposure and in all settlements of residing. To develop the model, WBC measurements data (around 1.5 millions) collected in 1987-2005 for population of around 1000 Belarusian settlements were used. The input data for IAEA int calculation include consumption of dose-significant products, duration, and place of residence obtained by mean of individual questionnaire; WBC measurements data; table of conformity (IFH → IAED int ). (author)

Field size and dose distribution of electron beam

International Nuclear Information System (INIS)

Kang, Wee Saing

1980-01-01

The author concerns some relations between the field size and dose distribution of electron beams. The doses of electron beams are measured by either an ion chamber with an electrometer or by film for dosimetry. We analyzes qualitatively some relations; the energy of incident electron beams and depths of maximum dose, field sizes of electron beams and depth of maximum dose, field size and scatter factor, electron energy and scatter factor, collimator shape and scatter factor, electron energy and surface dose, field size and surface dose, field size and central axis depth dose, and field size and practical range. He meets with some results. They are that the field size of electron beam has influence on the depth of maximum dose, scatter factor, surface dose and central axis depth dose, scatter factor depends on the field size and energy of electron beam, and the shape of the collimator, and the depth of maximum dose and the surface dose depend on the energy of electron beam, but the practical range of electron beam is independent of field size

An approach to routine individual internal dose monitoring at the object 'Shelter' personnel considering uncertainties

International Nuclear Information System (INIS)

Mel'nichuk, D.V.; Bondarenko, O.O.; Medvedjev, S.Yu.

2002-01-01

An approach to organisation of routine individual internal dose monitoring of the personnel of the Object 'Shelter' is presented in the work, that considers individualised uncertainties. In this aspect two methods of effective dose assessment based on bioassay are considered in the work: (1) traditional indirect method at which application results of workplace monitoring are not taken into account, and (2) a combined method in which both results of bioassay measurements and workplace monitoring are considered

Implication of new CEC recommendations for individual monitoring for external radiation doses to the skin and the extremities

International Nuclear Information System (INIS)

Christensen, P.; Julius, H.W.; Marshall, T.O.

1991-01-01

A drafting group consisting of the above authors has assisted the CEC in revising the CEC document Technical Recommendations for Monitoring the Exposure to Individuals to External Radiation, EUR 5287, published in 1975. The paper highlights sections of the revised version relating particularly to irradiation of the skin and the extremities and focusses on problems connected to exposure to weakly penetrating radiations. Concepts of individual monitoring for external radiation exposures to the skin of the whole body and to the extremities are discussed and guidance is given as regards dose quantities and dosemeter calibration procedures. A method of quantifying the overall accuracy of the dose measurements as a result of the various uncertainty components connected with the dosimetry system is suggested and requirements on the accuracy of the dose measurements complying with the ICRP requirements on overall accuracy for individual monitoring are specified. Moreover, implications of the accuracy requirements for the design and type testing of the dosemeter are discussed. (author)

Internal quality control program for individual monitoring service

Energy Technology Data Exchange (ETDEWEB)

Mauricio, Claudia L.P.; Moura Junior, Jose; Patrao, Karla C.S. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mail: claudia@ird.gov.br; moura@ird.gov.br; karla@ird.gov.br

2007-07-01

With a focus on continuous improvement, since 2002, a special internal procedure for following and checking the performance of our individual monitoring services has been implemented. A fictitious installation, named 'Fantasma' has been created, initially, with 4 film badges and 7 thermoluminescent dosimetric ring users. Since 2005, this quality control program includes also the albedo neutron individual monitoring service. Monthly, the 'Fantasma' test monitors are irradiated by traceable Cs-137 and Am-Be sources. The calibration quantities are: the photon dose equivalent (H{sub x}) for the photographic individual monitor, the maximum dose equivalent (MADE) for the albedo neutron individual monitor and the personal dose equivalent at 0.07 mm depth (H{sub p}(0.07)) for ring monitor. Up to now, all results show compliance with the specific trumpet curves acceptance limits. Once, a small sub-evaluation tendency has been noted and this information was used to improve the film system. For the photographic film system, the evaluated value to reference dose ratios range from 0.71 to 1.12, with a mean value of 0.91 {+-} 0.12. For the ring system, the ratio ranges from 0.69 to 1.40, with a mean value of 1.02 {+-} 0.07. For the neutron system, which presents intrinsic larger uncertainties, the ratio ranged from 0.67 to 1.88, with mean value of 1.16 {+-} 0.27. (author)

Intercomparison On Depth Dose Measurement

International Nuclear Information System (INIS)

Rohmah, N; Akhadi, M

1996-01-01

Intercomparation on personal dose evaluation system has been carried out between CSRSR-NAEA of Indonesia toward Standard Laboratory of JAERI (Japan) and ARL (Australia). The intercomparison was in 10 amm depth dose measurement , Hp (10), from the intercomparison result could be stated that personal depth dose measurement conducted by CSRSR was sufficiently good. Deviation of dose measurement result using personal dosemeter of TLD BG-1 type which were used by CSRSR in the intercomparison and routine photon personal dose monitoring was still in internationally agreed limit. Maximum deviation of reported doses by CSRSR compared to delivered doses for dosemeter irradiation by JAERI was -10.0 percent and by ARL was +29 percent. Maximum deviation permitted in personal dose monitoring is ± 50 percent

Cumulative radiation dose of multiple trauma patients during their hospitalization

International Nuclear Information System (INIS)

Wang Zhikang; Sun Jianzhong; Zhao Zudan

2012-01-01

Objective: To study the cumulative radiation dose of multiple trauma patients during their hospitalization and to analyze the dose influence factors. Methods: The DLP for CT and DR were retrospectively collected from the patients during June, 2009 and April, 2011 at a university affiliated hospital. The cumulative radiation doses were calculated by summing typical effective doses of the anatomic regions scanned. Results: The cumulative radiation doses of 113 patients were collected. The maximum,minimum and the mean values of cumulative effective doses were 153.3, 16.48 mSv and (52.3 ± 26.6) mSv. Conclusions: Multiple trauma patients have high cumulative radiation exposure. Therefore, the management of cumulative radiation doses should be enhanced. To establish the individualized radiation exposure archives will be helpful for the clinicians and technicians to make decision whether to image again and how to select the imaging parameters. (authors)

A method for assessing the annual dose to the most exposed individual from tritium and 14C reactor discharges to atmosphere

International Nuclear Information System (INIS)

Nair, S.

1979-10-01

A method is described for assessing the annual dose to the most exposed individual from routine releases of tritium and 14 C to the atmosphere during normal reactor operations. A detailed assessment has been made of the resulting equilibrium contamination levels in a range of foodstuffs typical of an average UK diet and of the annual doses resulting from a chronic intake of tritium and 14 C via inhalation, ingestion and, additionally, in the case of tritium, via skin absorption. Equilibrium annual doses from the global circulation of tritium and 14 C have also been calculated. Upper limits to the effective annual dose-equivalents to the most exposed individual were found to be 0.6 rem.yr -1 and 100 rem.yr -1 per Ci.yr -1 release of tritium and 14 C respectively, with the ingestion pathway contributing significantly to the overall exposure. The most exposed individual was found to be a Reference 10 year old child. The methods outlined for calculating the ingestion dose from tritium and 14 C releases hav been incorporated into the more generally applicable code FOODDOSE. The code may be used to make more realistic dose calculations to the individuals based on site-specific surveys of variables such as local meteorology, local diet and local land use for agriculture, which may lead to doses smaller than the upper limit values quoted by factors of 20 and 200 for tritium and 14 C respectively. (author)

Development of a kinetic model and calculation of radiation dose estimates for sodium iodide-{sup 131}I in athyroid individuals

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, M.

1997-07-01

The treatment for some thyroid carcinomas involves surgically removing the thyroid gland and administering the radiopharmaceutical Sodium iodide-{sup 131}I (NaI). A diagnostic dose of NaI is given to the patient to determine if remnant tissue from the gland remains or larger doses are administered in order to treat the malignant tissue. Past research regarding NaI uptake and retention in euthyroid individuals (normal functioning thyroid) reveal that radioiodine concentrates mainly in the thyroid tissue and the remaining material is excreted from the body. The majority of radioiodine in athyroid (without thyroid) individuals is also eliminated from the body; however, there has been recent evidence of a long-term retention phase for individuals with no radioiodine concentrating tissue. The general purpose of this study was to develop a kinetic model and estimate the absorbed dose to athyroid individuals regarding the distribution and retention of NaI.

Progress in structure recovery from low dose exposures: Mixed molecular adsorption, exploitation of symmetry and reconstruction from the minimum signal level

Energy Technology Data Exchange (ETDEWEB)

Kramberger, C., E-mail: Christian.Kramberger-Kaplan@univie.ac.at; Meyer, J.C., E-mail: Jannik.Meyer@univie.ac.at

2016-11-15

We investigate the recovery of structures from large-area, low dose exposures that distribute the dose over many identical copies of an object. The reconstruction is done via a maximum likelihood approach that does neither require to identify nor align the individual particles. We also simulate small molecular adsorbates on graphene and demonstrate the retrieval of images with atomic resolution from large area and extremely low dose raw data. Doses as low as 5 e{sup −}/Å{sup 2} are sufficient if all symmetries (translations, rotations and mirrors) of the supporting membrane are exploited to retrieve the structure of individual adsorbed molecules. We compare different optimization schemes, consider mixed molecules and adsorption sites, and requirements on the amount of data. We further demonstrate that the maximum likelihood approach is only count limited by requiring at least three independent counts per entity. Finally, we demonstrate that the approach works with real experimental data and in the presence of aberrations.

Contribution to optimization of individual doses of workers in shipment of generator technetium-99m

International Nuclear Information System (INIS)

Fonseca, Lizandra Pereira de Souza

2010-01-01

The Instituto de Pesquisas Energeticas e Nucleares, IPEN, radiopharmaceuticals research and produce that are distributed throughout Brazil, currently the radiopharmaceutical with the largest number of packaged shipped per year and with the highest total activity is the 99m technetium generator. To reduce individual doses for workers involved in the production of radiopharmaceuticals was performed a study of radiological protection optimization in the shipment process of technetium generator, using the techniques: differential cost-benefit analysis, integral cost-benefit analysis, multi-attribute utility analysis and multi-criteria outranking analysis. With changes in the configuration of packed for generator dispatch and with the acquirement of a mat transporter it was possible establish 4 protection options. The attributes considered were the protection cost, collective dose, individual dose and physical effort by worker to move the package without the mat. To assess the robustness of analytical solutions found with the techniques used in the optimization we performed a sensitivity study and found that option 3 is more robust than option 1, which is no longer the analytical solution with an increase of R$ 20.000,00 the cost of protection. (author)

Genetic variants associated with warfarin dose in African-American individuals: a genome-wide association study

Science.gov (United States)

Perera, Minoli A; Cavallari, Larisa H; Limdi, Nita A; Gamazon, Eric R; Konkashbaev, Anuar; Daneshjou, Roxana; Pluzhnikov, Anna; Crawford, Dana C; Wang, Jelai; Liu, Nianjun; Tatonetti, Nicholas; Bourgeois, Stephane; Takahashi, Harumi; Bradford, Yukiko; Burkley, Benjamin M; Desnick, Robert J; Halperin, Jonathan L; Khalifa, Sherief I; Langaee, Taimour Y; Lubitz, Steven A; Nutescu, Edith A; Oetjens, Matthew; Shahin, Mohamed H; Patel, Shitalben R; Sagreiya, Hersh; Tector, Matthew; Weck, Karen E; Rieder, Mark J; Scott, Stuart A; Wu, Alan HB; Burmester, James K; Wadelius, Mia; Deloukas, Panos; Wagner, Michael J; Mushiroda, Taisei; Kubo, Michiaki; Roden, Dan M; Cox, Nancy J; Altman, Russ B; Klein, Teri E; Nakamura, Yusuke; Johnson, Julie A

2013-01-01

Summary Background VKORC1 and CYP2C9 are important contributors to warfarin dose variability, but explain less variability for individuals of African descent than for those of European or Asian descent. We aimed to identify additional variants contributing to warfarin dose requirements in African Americans. Methods We did a genome-wide association study of discovery and replication cohorts. Samples from African-American adults (aged ≥18 years) who were taking a stable maintenance dose of warfarin were obtained at International Warfarin Pharmacogenetics Consortium (IWPC) sites and the University of Alabama at Birmingham (Birmingham, AL, USA). Patients enrolled at IWPC sites but who were not used for discovery made up the independent replication cohort. All participants were genotyped. We did a stepwise conditional analysis, conditioning first for VKORC1 −1639G→A, followed by the composite genotype of CYP2C9*2 and CYP2C9*3. We prespecified a genome-wide significance threshold of p<5×10−8 in the discovery cohort and p<0·0038 in the replication cohort. Findings The discovery cohort contained 533 participants and the replication cohort 432 participants. After the prespecified conditioning in the discovery cohort, we identified an association between a novel single nucleotide polymorphism in the CYP2C cluster on chromosome 10 (rs12777823) and warfarin dose requirement that reached genome-wide significance (p=1·51×10−8). This association was confirmed in the replication cohort (p=5·04×10−5); analysis of the two cohorts together produced a p value of 4·5×10−12. Individuals heterozygous for the rs12777823 A allele need a dose reduction of 6·92 mg/week and those homozygous 9·34 mg/week. Regression analysis showed that the inclusion of rs12777823 significantly improves warfarin dose variability explained by the IWPC dosing algorithm (21% relative improvement). Interpretation A novel CYP2C single nucleotide polymorphism exerts a clinically relevant

Maximum tolerated dose evaluation of the AMPA modulator Org 26576 in healthy volunteers and depressed patients: a summary and method analysis of bridging research in support of phase II dose selection.

Science.gov (United States)

Nations, Kari R; Bursi, Roberta; Dogterom, Peter; Ereshefsky, Larry; Gertsik, Lev; Mant, Tim; Schipper, Jacques

2012-09-01

A key challenge to dose selection in early central nervous system (CNS) clinical drug development is that patient tolerability profiles often differ from those of healthy volunteers (HVs), yet HVs are the modal population for determining doses to be investigated in phase II trials. Without clear tolerability data from the target patient population, first efficacy trials may include doses that are either too high or too low, creating undue risk for study participants and the development program overall. Bridging trials address this challenge by carefully investigating safety and tolerability in the target population prior to full-scale proof-of-concept trials. Org 26576 is an alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor positive allosteric modulator that acts by modulating ionotropic AMPA-type glutamate receptors to enhance glutamatergic neurotransmission. In preparation for phase II efficacy trials in major depressive disorder (MDD), two separate phase I trials were conducted to evaluate safety, tolerability, and pharmacokinetics in HVs and in the target patient population. Both trials were randomized and placebo controlled, and included multiple rising-dose cohorts (HV range 100-400 mg bid; MDD range 100-600 mg bid). HVs (n = 36) and patients with MDD (n = 54) were dosed under similarly controlled conditions in an inpatient facility, HVs for up to 14 days and MDD patients for up to 28 days. Safety, tolerability, and pharmacokinetics were assessed frequently. Despite comparable pharmacokinetic profiles, the maximum tolerated dose (MTD) in depressed patients was 450 mg bid, twice the MTD established in HVs. No clinically relevant safety issues associated with Org 26576 were noted. This article presents safety, tolerability, and pharmacokinetic data from two different populations examined under similar dosing conditions. The important implications of such bridging work in phase II dose selection are discussed, as are study

Comparsion of maximum viscosity and viscometric method for identification of irradiated sweet potato starch

International Nuclear Information System (INIS)

Yi, Sang Duk; Yang, Jae Seung

2000-01-01

A study was carried out to compare viscosity and maximum viscosity methods for the detection of irradiated sweet potato starch. The viscosity of all samples decreased by increasing stirring speeds and irradiation doses. This trend was similar for maximum viscosity. Regression coefficients and expressions of viscosity and maximum viscosity with increasing irradiation dose were 0.9823 (y=335.02e -0. 3 366x ) at 120 rpm and 0.9939 (y =-42.544x+730.26). This trend in viscosity was similar for all stirring speeds. Parameter A, B and C values showed a dose dependent relation and were a better parameter for detecting irradiation treatment than maximum viscosity and the viscosity value it self. These results suggest that the detection of irradiated sweet potato starch is possible by both the viscometric and maximum visosity method. Therefore, the authors think that the maximum viscosity method can be proposed as one of the new methods to detect the irradiation treatment for sweet potato starch

Individual monitoring of external exposure in terms of personal dose equivalent, Hp(d)

International Nuclear Information System (INIS)

Fantuzzi, E.

2001-01-01

The institute for Radiation Protection of ENEA - Bologna has organised a one day-workshop on the subject: Individual monitoring of external exposure in terms of personal dose equivalent, H p (d). The aim of the workshop was the discussion of the new implications and modifications to be expected in the routine individual monitoring of external radiation, due to the issue of the Decree 241/00 (G.U. 31/8/2000) in charge since 01/01/2001. The decree set up in Italian law the standards contained in the European Directive EURATOM 96/29-Basic Standards for the Protection of Health of Workers and the General Public against Dangers arising from Ionizing Radiation. Among others, the definition of the operational quantities for external radiation for personal and environmental monitoring, H p (d) e H * (d) respectively as defined by ICRU (International Commission for Radiation Units and Measurements), requires to update the methods of measurements and calibration of the personal dosemeters and environmental monitors. This report collects the papers presented at the workshop dealing with the Personal Dose Equivalent, H p (d), the conversion coefficients, H p (d)/K a e H p (d)/ , obtained through Monte Carlo calculations published by ICRU and ICRP (International Commission for Radiation Protection), the new calibration procedures and the practical implication in the routine of individual monitoring in terms of H p (d). Eventually, in the last chapter, the answers to Frequently Asked Questions (FAQ) are briefly reported [it

Individualized FSH dosing based on ovarian reserve testing in women starting IVF/ICSI: a multicentre trial and cost-effectiveness analysis.

Science.gov (United States)

van Tilborg, Theodora C; Oudshoorn, Simone C; Eijkemans, Marinus J C; Mochtar, Monique H; van Golde, Ron J T; Hoek, Annemieke; Kuchenbecker, Walter K H; Fleischer, Kathrin; de Bruin, Jan Peter; Groen, Henk; van Wely, Madelon; Lambalk, Cornelis B; Laven, Joop S E; Mol, Ben Willem J; Broekmans, Frank J M; Torrance, Helen L

2017-12-01

Is there a difference in live birth rate and/or cost-effectiveness between antral follicle count (AFC)-based individualized FSH dosing or standard FSH dosing in women starting IVF or ICSI treatment? In women initiating IVF/ICSI, AFC-based individualized FSH dosing does not improve live birth rates or reduce costs as compared to a standard FSH dose. In IVF or ICSI, ovarian reserve testing is often used to adjust the FSH dose in order to normalize ovarian response and optimize live birth rates. However, no robust evidence for the (cost-)effectiveness of this practice exists. Between May 2011 and May 2014 we performed a multicentre prospective cohort study with two embedded RCTs in women scheduled for IVF/ICSI. Based on the AFC, women entered into one of the two RCTs (RCT1: AFC 15) or the cohort (AFC 11-15). The primary outcome was ongoing pregnancy achieved within 18 months after randomization resulting in a live birth (delivery of at least one live foetus after 24 weeks of gestation). Data from the cohort with weight 0.5 were combined with both RCTs in order to conduct a strategy analysis. Potential half-integer numbers were rounded up. Differences in costs and effects between the two treatment strategies were compared by bootstrapping. In both RCTs women were randomized to an individualized (RCT1:450/225 IU, RCT2:100 IU) or standard FSH dose (150 IU). Women in the cohort all received the standard dose (150 IU). Anti-Müllerian hormone (AMH) was measured to assess AMH post-hoc as a biomarker to individualize treatment. For RCT1 dose adjustment was allowed in subsequent cycles based on pre-specified criteria in the standard group only. For RCT2 dose adjustment was allowed in subsequent cycles in both groups. Both effectiveness and cost-effectiveness of the strategies were evaluated from an intention-to-treat perspective. We included 1515 women, of whom 483 (31.9%) entered the cohort, 511 (33.7%) RCT1 and 521 (34.4%) RCT2. Live births occurred in 420/747 (56.3%) women

Issues of assessment of doses from natural sources in working conditions: implications for the unified state system of individual dose monitoring

Directory of Open Access Journals (Sweden)

T. A. Kormanovskaya

2017-01-01

Full Text Available The aims of the work are: 1 an analysis of information on radiation doses from natural sources of ionizing radiation of employees of enterprises in some industries of the Russian Federation and 2 an assessment of the state of registration of doses from natural sources in working conditions in the Unified System of Individual Dose Control. Materials and methods. The analysis was performed on the results of the operation of the Federal database of radiation doses of the population due to natural and artificial radiation background in 2013–2015 on the basis of the forms of the Federal statistical observation No. 4-DOZ in terms of collecting information on the radiation doses of workers in some non-nuclear industries due to natural sources of ionizing radiation. Results. Analysis of enterprises in 17 industries in 23 regions of Russia connected with the specificity of production processes showed cases of natural exposure of workers at the dose level exceeding 5 mSv/year. We have identified those branches of industry, for which the doses were close to 5 mSv/year.Examples of reducing the radiation doses by reducing the time spent by workers in workplaces with high levels of radiation are given. The problems of insufficient representativeness of the sample data are due to the lack of interaction of the management of industrial enterprises with the bodies of the Rospotrebnadzor. The obtained data allow speaking about the problem of assessing the quality of radiation control in the organizations where additional exposure of workers from natural radiation sources is expected. It is necessary to create a system of regulatory and procedural documents to solve the problem at the national level.

Radiation doses from discharges into the sea at the Oskarshamn nuclear power plants

International Nuclear Information System (INIS)

Boge, R.; Nordlinder, S.

1981-04-01

Control measurements of the activity discharges and the radioecological concentrations at the Oskarshamn site are reported. The actual discharges were much lower than the allowed maximum discharges. The calculated individual and collective doses are small, and the effect on the recipient is negligible, considering both men and ecosystems. (L.E.)

Individual doses control in the units of ministry of defence and ministry of interior and administration in the years 1986 - 2000

International Nuclear Information System (INIS)

Jazwinski, J.; Nowosielska, E.M.; Janiak, M.K.

2003-01-01

The aim of presented work was the assessment of occupational radiation exposure and its distribution among the workers of Ministry of Defence and Ministry of Interior and Administration in the years 1986 - 2000. the research was conducted on the basis of data collected by Laboratory of Radiological Inspection and Individual Doses Control, Department of Radiation Protection and Radiobiology Military Institute of Hygiene and Epidemiology, Warsaw, Poland. The workers occupationally exposed to radiation were divided into following groups: government department (Ministry of Defence or Ministry of Interior and Administration), according to the age (below 25, 26-35, 36-45, 46-55 and above 56 years old), sex, education, (elementary, secondary, university) or job (doctors, nurses, rtg technicians, etc.). The number of workers covered with individual doses control changed in Ministry of Defence from 689 (in 1986) to 1030 (in 2000), and in Ministry of Interior and Administration from 261 to 924 in the same period. The percent of workers, who received doses below 2 mSv per year varied in Ministry of Defence from 91,6% (in 1997) to 99,4% (in 1990), and in Ministry of Interior and Administration from 96,8% (in 1993) to 99,4 (in 2000). Almost 99% of workers occupationally exposed to radiation and covered with individual doses control received doses below 15 mSv, irrespective of year or department. The analysis of collected data revealed, that for a large majority of occupationally exposed workers the risk arising from contact with ionizing radiation is minimal (over 99% of workers covered with individual doses control received doses below 2 mSv per year), however there are critical groups of workers, for which the received equivalent doses were about 30 - 50 mSv. Increased doses of radiation, however not exceeding obligatory limits, are noticed for workers taking part in surgical operations in X radiation field, urologic operations and diagnostic and or working on several

Vitamin D supplementation in nursing home patients: randomized controlled trial of standard daily dose versus individualized loading dose regimen.

Science.gov (United States)

Wijnen, Hugo; Salemink, Dayenne; Roovers, Lian; Taekema, Diana; de Boer, Hans

2015-05-01

Supplementation of cholecalciferol 800 IU daily appears to be insufficient to raise vitamin D levels to >75 nmol/l in nursing home (NH) patients. Our objective was to compare the efficacy of an individualized cholecalciferol loading dose (LD) regimen and a daily dose (DD) regimen of cholecalciferol 800 IU in reaching 25-OH vitamin D (25OHD) levels >75 nmol/l. A total of 30 NH patients with 25OHD levels 50 nmol/l were included. Patients were randomized using the minimization method in the LD or DD group. The cholecalciferol LD, calculated with an algorithm based on serum 25OHD level and body weight, was administered in divided doses of 50,000 IU twice a week, followed by a monthly maintenance dose of either 50,000 or 25,000 IU. The DD regimen consisted of cholecalciferol 800 IU daily for 26 weeks. Serum 25OHD, calcium, creatinine, phosphate, and parathyroid hormone were measured, and 2-minute walking test, handgrip strength, and timed get up and go test were assessed at baseline (T 0), after 5 weeks (T 5), 12 weeks (T 12), and 26 weeks (T 26). The primary endpoint was the percentage of patients with 25OHD levels >75 nmol/l at T 5. Secondary endpoints were the proportion of patients with 25OHD levels >75 nmol/l at T 26, safety of LD regimen, and improvement of performance tests with normalization of vitamin D levels. Median baseline 25OHD levels (interquartile range) were comparable between the 14 DD and 16 LD patients: 20.9 (15.9-29.6) and 21.7 (16.4-32.8) nmol/l, respectively. Levels of 25OHD >75 nmol/l at T 5 were reached in 79 % of the 14 LD patients, but in none of the 13 DD patients (p 75 nmol/l were reached in 83 % of the 12 LD patients and in 30 % of the ten DD patients (p tests was observed. In NH patients with severe 25OHD deficiency, an individualized calculated cholecalciferol LD is likely to be superior to a DD of cholecalciferol 800 IU in terms of the ability to rapidly normalize vitamin D levels.

Effective dose in individuals from exposure the patients treated with 131I using Monte Carlo method

International Nuclear Information System (INIS)

Carvalho Junior, Alberico B. de; Silva, Ademir X.

2007-01-01

In this work, using the Visual Monte Carlo code and the voxel phantom FAX, elaborated similar scenes of irradiation to the treatments used in the nuclear medicine, with the intention of estimate the effective dose in individuals from exposure the patients treated with 131 I. We considered often specific situations, such as doses to others while sleeping, using public or private transportation, or being in a cinema for a few hours. In the possible situations that has been considered, the value of the effective dose did not overcome 0.05 mSv, demonstrating that, for the considered parameters the patient could be release without receiving instructions from radioprotection. (author)

Modelling of hand phantoms and optimisation of dose measurements in inhomogeneous beta-photon radiation fields using the MCNP code

International Nuclear Information System (INIS)

Becker, Frank; Blunck, Christoph; Hegenbart, Lars; Heide, Bernd; Leone, Debora; Nagels, Sven; Schimmelpfeng, Jutta; Urban, Manfred

2008-01-01

Inhomogeneous beta-photon radiation fields make a reliable dose difficult to determine. Routine monitoring with dosemeters does not guarantee any accurate determination of the local skin dose. In general, correction factors are used to correct for the measured dose and the maximum exposure. However, strong underestimations of the maximum exposure are possible, depending on the individual handling and the reliability of dose measurements. Simulations provide the possibility to track the points of highest exposure and the origin of the highest dose. In this connection, simulations are performed with MCNPX. In order to investigate the local skin dose, two hand phantoms are used, a model based on geometrical elements and a voxel hand. A typical case of radio synoviorthesis, handling of a syringe filled with 90 Y, is simulated. Another simulation focuses on the selective internal radio therapy, revealing the origin of the main dose component in the mixed beta-photon radiation field of a 90 Y vial in an opened transport container. (author)

Does low-dose CCK-8 injection produce abdominal pain in 'truly normal' individuals?

International Nuclear Information System (INIS)

Ramsay, S.; Webb, B.; Hille, N.

1999-01-01

Full text: The development of abdominal pain following cholecystokinin (CCK) injection is not specific for biliary disease. Patients can develop abdominal pain with CCK during hepatobiliary studies and have normal gallbladder function. Does this non-biliary pain indicate pathology? High doses of CCK induce pain in functional bowel syndromes, but may also produce pain in normals. Pain is less common at lower CCK doses, and hence may be more significant. This study aimed to determine the rate at which the low dose of CCK used in hepatobiliary scans causes abdominal pain and other side-effects in 'truly normal' individuals. Some preliminary results of CCK-induced pain in gastro-oesophageal reflux (GOR) patients are also discussed. Six 'truly normal' subjects were studied. 'Truly normal' was defined as: no current history of abdominal pain; no biliary or gallbladder disease; no significant GIT pathology; not currently on medication designed to be pharmacologically active in the GIT. Each patient was given an intravenous dose of 0.01 μg-kg -1 of CCK8 over 3 min, and side-effects were recorded for 30 min. No subject had abdominal pain. Two developed nausea, 1 moderate and 1 mild. An identical dose of CCK was given to 2 patients with endoscopically proven GOR. Anti-reflux medication had been ceased for 12 h. After CCK, 1 patient developed typical 'reflux' pain and 1 was asymptomatic. In conclusion, none of our 'truly normal' patients had abdominal pain with low-dose CCK. This suggests that patients developing pain following injection of this dose of CCK are indeed abnormal. The literature infers these patients may have irritable bowel syndrome; however, this hypothesis is complicated by our preliminary results indicating that CCK can reproduce pain in some patients with GOR

Maximum Power from a Solar Panel

Directory of Open Access Journals (Sweden)

Michael Miller

2010-01-01

Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

Calculation of individual and population doses on Danish territory resulting from hypothetical core-melt accidents at the Barsebaeck reactor

International Nuclear Information System (INIS)

1977-01-01

Individual and population doses within Danish territory are calculated from hypothetical, severe core-melt accidents at the Swedish nuclear plant at Barsebaeck. The fission product inventory of the Barsebaeck reactor is calculated. The release fractions for the accidents are taken from WASH-1400. Based on parametric studies, doses are calculated for very unfavourable, but not incredible weather conditions. The probability of such conditions in combination with wind direction towards Danish territory is estimated. Doses to bone marrow, lungs, GI-tract and thyroid are calculated based on dose models developed at Risoe. These doses are found to be consistent with doses calculated with the models used in WASH-1400. (author)

Radiological dose assessment from the operation of Daeduk nuclear facilities

Energy Technology Data Exchange (ETDEWEB)

Hwang, Won Tae; Kim, Eun Han; Suh, Kyung Suk; Choi, Young Gil [Korea Atomic Energy Research Institute, Taejon (Korea)

2000-02-01

The objective of this project is to assure the public acceptance for nuclear facilities, and the environmental safety from the operation of Daeduk nuclear facilities, such as HANARO research reactor, nuclear fuel processing facilities and others. For identifying the integrity of their facilities, the maximum individual doses at the site boundary and on the areas with high population density were assessed. Also, the collective doses within radius 80 km from the site were assessed. The radiation impacts for residents around the site from the operation of Daeduk nuclear facilities in 1999 were neglectable. 8 refs., 10 figs., 27 tabs. (Author)

The choice of individual dose criterion at which to restrict agricultural produce following an unplanned release of radioactive material to atmosphere

CERN Document Server

Dionian, J

1985-01-01

In the event of an accidental release of radioactive material to atmosphere, the introduction of emergency countermeasures will be based on the need to limit the risk to individuals. However, it has been suggested that a form of cost-benefit analysis may be used as an input to decisions on the withdrawal of countermeasures, although it is recognised that these decisions may be influenced by factors other than those directly related to radiological protection. In this study, a method based on cost-benefit analysis is illustrated for assessing the optimum level of individual dose at which restrictions on agricultural production may be considered. This requires monetary values to be assigned to both the lost food production and to the health detriment, expressed as the collective effective dose equivalent commitment. It has been assumed in this analysis that food-supply restrictions are both introduced and withdrawn at the same projected level of annual individual dose. The effect on the optimum dose level of th...

An estimate of the maximal doses incurred by persons accompanying patients in the waiting area of a nuclear medicine department

International Nuclear Information System (INIS)

Dzik-Jurasz, A.S.K.; Farwell, J.

1997-01-01

The aim of the study was to make an estimate of the maximal doses that might be incurred by persons accompanying active patients in a nuclear medicine department waiting area. This was in order to determine whether the dose to such individuals approached current legislative or recently recommended limits. Thermoluminescent dosemeters were taped to the walls of the waiting area at waist level to the sitting individual, such that their record would reflect as closely as possible the dose incurred by an individual sitting next to an active patient. Dividing the recorded dose with the total occupancy time of that seat derived an average dose rate. Maximal doses were estimated by the product of the latter and maximal occupancy times. It was assumed that an accompanying individual would have been sitting next to the active patient for their whole duration of stay. The maximum estimates were 278 μSv and 103.2 μSv. These values are likely to be overestimates by the virtue of the TLD integrating the whole dose of its surrounds, especially adjacent active individuals. By current legislation and recent recommendations the values are reassuringly low, but idiosyncrasies in local practice might need to be considered in individual departments. (author)

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

International Nuclear Information System (INIS)

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

1980-01-01

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

Evaluation of concave dose distributions created using an inverse planning system

International Nuclear Information System (INIS)

Hunt, Margie A.; Hsiung, C.-Y.; Spirou, Spirodon V.; Chui, C.-S.; Amols, Howard I.; Ling, Clifton C.

2002-01-01

Purpose: To evaluate and develop optimum inverse treatment planning strategies for the treatment of concave targets adjacent to normal tissue structures. Methods and Materials: Optimized dose distributions were designed using an idealized geometry consisting of a cylindrical phantom with a concave kidney-shaped target (PTV) and cylindrical normal tissues (NT) placed 5-13 mm from the target. Targets with radii of curvature from 1 to 2.75 cm were paired with normal tissues with radii between 0.5 and 2.25 cm. The target was constrained to a prescription dose of 100% and minimum and maximum doses of 95% and 105% with relative penalties of 25. Maximum dose constraint parameters for the NT varied from 10% to 70% with penalties from 10 to 1000. Plans were evaluated using the PTV uniformity index (PTV D max /PTV D 95 ) and maximum normal tissue doses (NT D max /PTV D 95 ). Results: In nearly all situations, the achievable PTV uniformity index and the maximum NT dose exceeded the corresponding constraints. This was particularly true for small PTV-NT separations (5-8 mm) or strict NT dose constraints (10%-30%), where the achievable doses differed from the requested by 30% or more. The same constraint parameters applied to different PTV-NT separations yielded different dose distributions. For most geometries, a range of constraints could be identified that would lead to acceptable plans. The optimization results were fairly independent of beam energy and radius of curvature, but improved as the number of beams increased, particularly for small PTV-NT separations or strict dose constraints. Conclusion: Optimized dose distributions are strongly affected by both the constraint parameters and target-normal tissue geometry. Standard site-specific constraint templates can serve as a starting point for optimization, but the final constraints must be determined iteratively for individual patients. A strategy whereby NT constraints and penalties are modified until the highest

Effective dose and dose to crystalline lens during angiographic procedures

International Nuclear Information System (INIS)

Pages, J.

1998-01-01

The highest radiation doses levels received by radiologists are observed during interventional procedures. Doses to forehead and neck received by a radiologist executing angiographic examinations at the department of radiology at the academic hospital (AZ-VUB) have been measured for a group of 34 examinations. The doses to crystalline lens and the effective doses for a period of one year have been estimated. For the crystalline lens the maximum dose approaches the ICRP limit, that indicates the necessity for the radiologist to use leaded glasses. (N.C.)

The steady-state pharmacokinetics of nevirapine during once daily and twice daily dosing in HIV-1-infected individuals

NARCIS (Netherlands)

van Heeswijk, R. P.; Veldkamp, A. I.; Mulder, J. W.; Meenhorst, P. L.; Wit, F. W.; Lange, J. M.; Danner, S. A.; Foudraine, N. A.; Kwakkelstein, M. O.; Reiss, P.; Beijnen, J. H.; Hoetelmans, R. M.

2000-01-01

OBJECTIVE: To investigate and to compare the steady-state plasma pharmacokinetics of nevirapine in a dosing regimen of 400 mg once daily versus 200 mg twice daily in HIV-1-infected individuals. DESIGN: Open-label, randomized, cross-over study. METHODS: Twenty HIV-1-infected individuals who already

Individual dose reconstruction among residents living in the vicinity of the Semipalatinsk nuclear test site using EPR spectroscopy of tooth enamel.

Science.gov (United States)

Ivannikov, A I; Zhumadilov, Zh; Gusev, B I; Miyazawa, Ch; Jiao, L; Skvortsov, V G; Stepanenko, V F; Takada, J; Hoshi, M

2002-08-01

Individual accumulated doses were determined by EPR spectroscopy of tooth enamel for 26 adult persons residing in territories adjacent to the Semipalatinsk Nuclear Test Site (SNTS). The absorbed dose values due to radiation from nuclear tests were obtained after subtracting the contribution of natural background radiation from the total accumulated dose. The determined dose values ranged up to 250 mGy, except for one person from Semipalatinsk city with a measured dose of 2.8 +/- 0.4 Gy. Increased dose values were determined for the individuals whose teeth were formed before 1962, the end of the atmospheric nuclear tests. These values were found to be significantly larger than those obtained for a group of younger residents of heavily exposed territories and the residents of territories not exposed to radioactive fallout. These increased dose values are consistent with those based on officially registered data for the Northeastern part of Kazakstan adjacent to SNTS, which was exposed to high levels of radioactive fallout from nuclear tests in period 1949-1962.

Is the maximum permissible radiation burden for the population indeed permissible

International Nuclear Information System (INIS)

Renesse, R.L. van.

1975-01-01

It is argued that legislation based on the ICRP doses will, under economical influences, lead to a situation where the population is exposed to radiation doses near the maximum permissible dose. Due to cumulative radiation effects, this will introduce unacceptable health risks. Therefore, it will be necessary to lower the legal dose limit of 170 millrem per year per person by a factor 10 to 20

Individual Module Maximum Power Point Tracking for a Thermoelectric Generator Systems

DEFF Research Database (Denmark)

Vadstrup, Casper; Chen, Min; Schaltz, Erik

Thermo Electric Generator (TEG) modules are often connected in a series and/or parallel system in order to match the TEG system voltage with the load voltage. However, in order to be able to control the power production of the TEG system a DC/DC converter is inserted between the TEG system...... and the load. The DC/DC converter is under the control of a Maximum Power Point Tracker (MPPT) which insures that the TEG system produces the maximum possible power to the load. However, if the conditions, e.g. temperature, health, etc., of the TEG modules are different each TEG module will not produce its...

Assessment of pancreatic adenocarcinoma: use of low-dose whole pancreatic CT perfusion and individualized dual-energy CT scanning

International Nuclear Information System (INIS)

Li, Hai-ou; Guo, Jun; Li, Xiao; Qi, Yao-dong; Wang, Xi-ming; Xu, Zhuo-dong; Liu, Cheng; Chen, Jiu-hong

2015-01-01

The objective of this study was to investigate the value of low-dose whole pancreatic computed tomography (CT) perfusion integrated with individualized dual-energy CT (DECT) scanning in the diagnosis of pancreatic adenocarcinoma. Twenty patients with pancreatic adenocarcinoma underwent pancreatic CT perfusion as well as individualized dual-phase DECT pancreatic scans. Perfusion characteristics of non-tumourous pancreatic parenchyma and pancreatic adenocarcinoma were analysed. Weighted-average 120 kVp images and the optimal monoenergetic images in dual phase were reconstructed and the contrast noise ratio (CNR) of pancreas-to-tumour were compared. There were significant difference on blood flow as well as blood volume between pancreatic adenocarcinoma and the non-tumourous pancreatic parenchyma (P < 0.05), whereas no difference on permeability (P > 0.05). CNRs of pancreas-to-tumour in individualized pancreatic phase were significantly higher than those in venous phase (P < 0.05), and CNRs of optimal monoenergetic images were higher than those on weighted-average 120 kVp images (P < 0.05) in both phase. Total effective radiation dose of CT examination was around 9.32–13.75 mSv. Low-dose whole pancreatic CT perfusion can provide functional information, and the individualized pancreatic phase DECT scan is the optimal method for detecting pancreatic adenocarcinomas. The integration of the two techniques has great value in clinical application.

Radiation doses from residual radioactivity

International Nuclear Information System (INIS)

Okajima, Shunzo; Fujita, Shoichiro; Harley, John H.

1987-01-01

In this chapter available data and calculations for assessing the exposure of survivors of the Hiroshima and Nagasaki bombs and persons who entered the cities after the bombings have been presented. It appears that it is possible to produce firm estimates only for external radiation and, while the internal contribution for long-lived fission products appears small, there is no way to evaluate potential exposures to the short-lived fission products. The radiation exposure in the most highly contaminated fallout area of a few hectares at Nishiyama, Nagasaki, is estimated as 20 to 40 R when integrated from one hour to infinity using a decay exponent of -1.2. For the Hiroshima Koi-Takasu area, the corresponding exposure is estimated as 1 to 3 R. The falloff with distance for Nagasaki is not steep and an exposure of one-fifth of the maximum is spread over an area of perhaps 1000 ha. With the assumption stated above, the potential maximum exposures to external radiation from induced radioactivity at the hypocenter is estimated to be about 80 R fir Hiroshima and 30 to 40 R for Nagasaki with the assumptions stated above. These exposures fall off with both time and distance. The cumulative exposure would be about one-third as large after a day and only a few percent after a week. The falloff with distance is less striking, but can be estimated from the areas listed or from the curves shown in Gritzner and Woolson. Unlike the fallout, which exposed individuals in their living areas, exposures to induced activity came from reentry of individuals into the area around the hypocenter. As an example, an individual entering the Hiroshima hypocenter area after one day and working 10 or 20 hours a day for a week would have been exposed to about 10 R. If the person had been working at a distance of 500 m, the exposure would have been about 1 R and, at 1000 m, about 20 mR. The exposure described apply to the specified areas in the two cities. Application of these values to individuals

A smoothed maximum score estimator for the binary choice panel data model with individual fixed effects and applications to labour force participation

NARCIS (Netherlands)

Charlier, G.W.P.

1994-01-01

In a binary choice panel data model with individual effects and two time periods, Manski proposed the maximum score estimator, based on a discontinuous objective function, and proved its consistency under weak distributional assumptions. However, the rate of convergence of this estimator is low (N)

Influence of Genotype on Warfarin Maintenance Dose Predictions Produced Using a Bayesian Dose Individualization Tool.

Science.gov (United States)

Saffian, Shamin M; Duffull, Stephen B; Roberts, Rebecca L; Tait, Robert C; Black, Leanne; Lund, Kirstin A; Thomson, Alison H; Wright, Daniel F B

2016-12-01

A previously established Bayesian dosing tool for warfarin was found to produce biased maintenance dose predictions. In this study, we aimed (1) to determine whether the biased warfarin dose predictions previously observed could be replicated in a new cohort of patients from 2 different clinical settings, (2) to explore the influence of CYP2C9 and VKORC1 genotype on predictive performance of the Bayesian dosing tool, and (3) to determine whether the previous population used to develop the kinetic-pharmacodynamic model underpinning the Bayesian dosing tool was sufficiently different from the test (posterior) population to account for the biased dose predictions. The warfarin maintenance doses for 140 patients were predicted using the dosing tool and compared with the observed maintenance dose. The impact of genotype was assessed by predicting maintenance doses with prior parameter values known to be altered by genetic variability (eg, EC50 for VKORC1 genotype). The prior population was evaluated by fitting the published kinetic-pharmacodynamic model, which underpins the Bayesian tool, to the observed data using NONMEM and comparing the model parameter estimates with published values. The Bayesian tool produced positively biased dose predictions in the new cohort of patients (mean prediction error [95% confidence interval]; 0.32 mg/d [0.14-0.5]). The bias was only observed in patients requiring ≥7 mg/d. The direction and magnitude of the observed bias was not influenced by genotype. The prior model provided a good fit to our data, which suggests that the bias was not caused by different prior and posterior populations. Maintenance doses for patients requiring ≥7 mg/d were overpredicted. The bias was not due to the influence of genotype nor was it related to differences between the prior and posterior populations. There is a need for a more mechanistic model that captures warfarin dose-response relationship at higher warfarin doses.

Individualized drug dosing using RBF-Galerkin method: Case of anemia management in chronic kidney disease.

Science.gov (United States)

Mirinejad, Hossein; Gaweda, Adam E; Brier, Michael E; Zurada, Jacek M; Inanc, Tamer

2017-09-01

Anemia is a common comorbidity in patients with chronic kidney disease (CKD) and is frequently associated with decreased physical component of quality of life, as well as adverse cardiovascular events. Current treatment methods for renal anemia are mostly population-based approaches treating individual patients with a one-size-fits-all model. However, FDA recommendations stipulate individualized anemia treatment with precise control of the hemoglobin concentration and minimal drug utilization. In accordance with these recommendations, this work presents an individualized drug dosing approach to anemia management by leveraging the theory of optimal control. A Multiple Receding Horizon Control (MRHC) approach based on the RBF-Galerkin optimization method is proposed for individualized anemia management in CKD patients. Recently developed by the authors, the RBF-Galerkin method uses the radial basis function approximation along with the Galerkin error projection to solve constrained optimal control problems numerically. The proposed approach is applied to generate optimal dosing recommendations for individual patients. Performance of the proposed approach (MRHC) is compared in silico to that of a population-based anemia management protocol and an individualized multiple model predictive control method for two case scenarios: hemoglobin measurement with and without observational errors. In silico comparison indicates that hemoglobin concentration with MRHC method has less variation among the methods, especially in presence of measurement errors. In addition, the average achieved hemoglobin level from the MRHC is significantly closer to the target hemoglobin than that of the other two methods, according to the analysis of variance (ANOVA) statistical test. Furthermore, drug dosages recommended by the MRHC are more stable and accurate and reach the steady-state value notably faster than those generated by the other two methods. The proposed method is highly efficient for

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Patient doses in digital cardiac imaging

International Nuclear Information System (INIS)

Huda, W.; Ogden, K.M.; Roskopf, M.L.; Phadke, K.

2001-01-01

In this pilot study, we obtained estimates of entrance skin doses and the corresponding effective doses to patients undergoing digital cardiac imaging procedures on a GE Advantx LC/LP Plus system. Data were obtained for six patients undergoing diagnostic examinations and six patients who had interventional procedures. For each patient examination, radiographic techniques for fluoroscopic and digital cine imaging were recorded, together with the irradiation geometry. The projection with the highest exposure resulted in an average skin dose of 0.64 ± 0.41 Gy (maximum of 1.6 Gy). The average patient skin doses taking into account overlapping projections was 1.1 ± 0.8 Gy (maximum of 3.0 Gy). The exposure area product (EAP) incident on the patient was converted into the energy imparted to the patient and the corresponding effective dose. The average patient effective dose was 28 ± 14 mSv (maximum 62 mSv), with the resultant average fatal cancer risk estimated to be of the order of 8x10 -3 . Average doses for interventional procedures in cardiac imaging are higher than those associated with diagnostic examinations by approximately 50%. (author)

Failure-probability driven dose painting

International Nuclear Information System (INIS)

Vogelius, Ivan R.; Håkansson, Katrin; Due, Anne K.; Aznar, Marianne C.; Kristensen, Claus A.; Rasmussen, Jacob; Specht, Lena; Berthelsen, Anne K.; Bentzen, Søren M.

2013-01-01

Purpose: To demonstrate a data-driven dose-painting strategy based on the spatial distribution of recurrences in previously treated patients. The result is a quantitative way to define a dose prescription function, optimizing the predicted local control at constant treatment intensity. A dose planning study using the optimized dose prescription in 20 patients is performed.Methods: Patients treated at our center have five tumor subvolumes from the center of the tumor (PET positive volume) and out delineated. The spatial distribution of 48 failures in patients with complete clinical response after (chemo)radiation is used to derive a model for tumor control probability (TCP). The total TCP is fixed to the clinically observed 70% actuarial TCP at five years. Additionally, the authors match the distribution of failures between the five subvolumes to the observed distribution. The steepness of the dose–response is extracted from the literature and the authors assume 30% and 20% risk of subclinical involvement in the elective volumes. The result is a five-compartment dose response model matching the observed distribution of failures. The model is used to optimize the distribution of dose in individual patients, while keeping the treatment intensity constant and the maximum prescribed dose below 85 Gy.Results: The vast majority of failures occur centrally despite the small volumes of the central regions. Thus, optimizing the dose prescription yields higher doses to the central target volumes and lower doses to the elective volumes. The dose planning study shows that the modified prescription is clinically feasible. The optimized TCP is 89% (range: 82%–91%) as compared to the observed TCP of 70%.Conclusions: The observed distribution of locoregional failures was used to derive an objective, data-driven dose prescription function. The optimized dose is predicted to result in a substantial increase in local control without increasing the predicted risk of toxicity

Effective dose in individuals from exposure the patients treated with {sup 131}I using Monte Carlo method

Energy Technology Data Exchange (ETDEWEB)

Carvalho Junior, Alberico B. de; Silva, Ademir X. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: ajunior@con.ufrj.br; Hunt, John G. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN), Rio de Janeiro, RJ (Brazil)]. E-mail: john@ird.gov.br

2007-07-01

In this work, using the Visual Monte Carlo code and the voxel phantom FAX, elaborated similar scenes of irradiation to the treatments used in the nuclear medicine, with the intention of estimate the effective dose in individuals from exposure the patients treated with {sup 131}I. We considered often specific situations, such as doses to others while sleeping, using public or private transportation, or being in a cinema for a few hours. In the possible situations that has been considered, the value of the effective dose did not overcome 0.05 mSv, demonstrating that, for the considered parameters the patient could be release without receiving instructions from radioprotection. (author)

Skull base chordomas: analysis of dose-response characteristics

International Nuclear Information System (INIS)

Niemierko, Andrzej; Terahara, Atsuro; Goitein, Michael

1997-01-01

parameters of the time-dose-response relationship for the analyzed group of patients. For example, the maximum likelihood estimates of surviving fraction at 2Gy (SF 2 ) are 0.47 with 95% confidence limits of [0.45-0.49] for male and 0.53 [0.51-0.55] for female, with the coefficient of inter-patient variation in SF 2 of 4.3%. The density of clonogens was estimated to be 10 8.2 clonogens per cubic centimeter. In effect, the slope of the dose-response curve, γ 50 , was estimated to be 2.7 [1.9-3.2] for both male and female, and the ED 50 doses to be 67Gy and 73Gy respectively. Skull base chordomas of the female patients seemed to be not only more resistant to radiation but also recurring faster than that for male patients (the maximum likelihood estimates of the Weibull shape parameter β are 2.6 for female and 1.7 for male patients). Conclusions: This analysis revealed several clinically important characteristics of radioresponsiveness of skull base chordomas. The comprehensive patient data obtained using three-dimensional treatment planning system allowed us to demonstrate and quantify the existence of dose-response and dose-volume relationships. In consequence, we are able to estimate prospectively the individual's probability of staying recurrence-free and her/his overall survival characteristics as a function of the applied three-dimensional dose distribution and time after treatment. Based on the analysis our treatment protocols have been modified to account for differences in radiosensitivity between female and male patients

Dose assessment of remedial action for uranium tailing impoundment of a nuclear factory

International Nuclear Information System (INIS)

Li Xutong; Ma Ruwei; Guo Zede

2000-01-01

A large uranium tailing impoundment in China will be closure and remedial action have been planned. The remedial action will include shaping and covering the dam and beach in order to prevent the impoundment from damage and restrict spread of tailing sands and emission of radon. The author presents the analysis and estimation of the exposure to workers for remedial action and to public after the remedial action. To estimate the exposure to workers, the pathway of inhalation of radon, tailing sands in suspension and external γ exposure were taken into consideration. The exposure scenario is considered as probably maximum exposure to the workers who work on the tailing pile without any protection measures, the dose is 6.0 mSv/a. Two situation for the exposure to public after remedial action were considered: normal and abnormal condition. For the normal condition, inhalation of radon emitted from impoundment is only the pathway to public for the exposure, and individual dose for critical group of public is 0.053 mSv/a, collective dose for population within 80 km is 1.0 man·Sv/a. For the abnormal conditions, four scenarios were considered, i.e. dwelling on tailing pile, farming on tailing pile, living in a house built by contaminated materials and some temporal activities on the pile. The scenarios of dwellings is living in a house on the pile and drinking contaminated water. The maximum individual dose is 27 mSv/a

Application of ICRP recommendations relevant to internal dose

International Nuclear Information System (INIS)

Cowser, K.E.; Snyder, W.S.; Struxness, E.G.

1969-01-01

The intent of this paper is to review several of the basic concepts of radiation protection (with emphasis on internal dose) currently recommended by the International Commission on radiological Protection (ICRP), to summarize the assumptions and methods used in the calculation of internal dose, and to illustrate by example the practical application of the pertinent guidelines. Two broad subject areas are considered: (1) standards of radiation protection and (2) bases of internal dose estimation. Topics discussed within the framework of radiation protection standards include maximum permissible dose, categories of radiation exposure, maximum permissible dose commitment, simultaneous internal and external exposure, multiple organ exposure, and size of the exposed group. Discussion of internal dose estimation is limited to selected items that include the body burden of radionuclides and the calculation of absorbed dose, the dose equivalent, the derivation of maximum permissible concentration (MPC), the relationship of stable element intake to the MPC, and short term and chronic exposure situations. (author)

Application of ICRP recommendations relevant to internal dose

Energy Technology Data Exchange (ETDEWEB)

Cowser, K E; Snyder, W S; Struxness, E G [Health Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

1969-07-01

The intent of this paper is to review several of the basic concepts of radiation protection (with emphasis on internal dose) currently recommended by the International Commission on radiological Protection (ICRP), to summarize the assumptions and methods used in the calculation of internal dose, and to illustrate by example the practical application of the pertinent guidelines. Two broad subject areas are considered: (1) standards of radiation protection and (2) bases of internal dose estimation. Topics discussed within the framework of radiation protection standards include maximum permissible dose, categories of radiation exposure, maximum permissible dose commitment, simultaneous internal and external exposure, multiple organ exposure, and size of the exposed group. Discussion of internal dose estimation is limited to selected items that include the body burden of radionuclides and the calculation of absorbed dose, the dose equivalent, the derivation of maximum permissible concentration (MPC), the relationship of stable element intake to the MPC, and short term and chronic exposure situations. (author)

High-dose statin therapy in patients with stable coronary artery disease: treating the right patients based on individualized prediction of treatment effect

NARCIS (Netherlands)

Dorresteijn, Johannes A. N.; Boekholdt, S. Matthijs; van der Graaf, Yolanda; Kastelein, John J. P.; LaRosa, John C.; Pedersen, Terje R.; Demicco, David A.; Ridker, Paul M.; Cook, Nancy R.; Visseren, Frank L. J.

2013-01-01

Clinicians need to identify coronary artery disease patients for whom the benefits of high-dose versus usual-dose statin therapy outweigh potential harm. We therefore aimed to develop and validate a model for prediction of the incremental treatment effect of high-dose statins for individual patients

Measurements of dose with individual FAMOS transistors

Energy Technology Data Exchange (ETDEWEB)

Scheick, L.Z.; McNulty, P.J.; Roth, D.R.; Davis, M.G.; Mason, B.E.

1999-12-01

A new method is described for measuring the doses absorbed by microstructures from an exposure to ionizing radiation. The decrease in the duration of UltraViolet light (UV) exposure required to erase each cell of a commercial UltraViolet erasable Programmable Read Only Memory (UVPROM) correlates with the dose absorbed by the floating gate of that transistor. This technique facilitates analysis of the microdose distribution across the array and the occurrence of Single Event Upset (SEU) like anomalous shifts due to rare large energy-deposition events.

Measurements of dose with individual FAMOS transistors

International Nuclear Information System (INIS)

Scheick, L.Z.; McNulty, P.J.; Roth, D.R.; Davis, M.G.; Mason, B.E.

1999-01-01

A new method is described for measuring the doses absorbed by microstructures from an exposure to ionizing radiation. The decrease in the duration of UltraViolet light (UV) exposure required to erase each cell of a commercial UltraViolet erasable Programmable Read Only Memory (UVPROM) correlates with the dose absorbed by the floating gate of that transistor. This technique facilitates analysis of the microdose distribution across the array and the occurrence of Single Event Upset (SEU) like anomalous shifts due to rare large energy-deposition events

Population dose commitments due to radioactive releases from nuclear power plant sites in 1988

International Nuclear Information System (INIS)

Baker, D.A.

1992-01-01

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1988. Fifty-year commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 71 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total collective dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 16 person-rem to a low of 0.0011 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 1.1 person-rem. The total population dose for all sites was estimated at 75 person-rem for the 150 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 3 x 10 -7 mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. However, licensee calculation of doses to the maximally exposed individual at some sites indicated values of up to approximately 100 times average individual doses (on the order of a few millirem per year)

COSANI-2, Gamma Doses from SABINE Calculation, Activity from ANISN Flux Calculation

International Nuclear Information System (INIS)

Dupont, C.

1975-01-01

1 - Nature of physical problem solved: Retrieval of SABINE and/or ANISN results. Calculates in case of SABINE results the individual contributions of capture gamma rays in each region to the total gamma dose and to the total gamma heating may calculate in case of ANISN new activity rates starting from ANISN flux saved on tape and activity cross sections taken on an ANISN binary library tape. The program can draw on a BENSON plotter any of the following quantities: - group flux; - activity rates; - dose rates; - neutron spectra for SABINE; - neutron or gamma direct or adjoint spectra for ANISN; - gamma heating and dose rate for SABINE including individual contributions from each region. Several ANISN and/or SABINE cases can be drawn on the same graph for comparison purposes. 2 - Restrictions on the complexity of the problem: Maximum number of: - tapes containing ANISN and/or SABINE results: 5; - curves per graph: 3; - regions: 40; - points per curve: 500; - energy groups: 200

Dose-Response of Sodium Bicarbonate Ingestion Highlights Individuality in Time Course of Blood Analyte Responses.

Science.gov (United States)

Jones, Rebecca Louise; Stellingwerff, Trent; Artioli, Guilherme Giannini; Saunders, Bryan; Cooper, Simon; Sale, Craig

2016-10-01

To defend against hydrogen cation accumulation and muscle fatigue during exercise, sodium bicarbonate (NaHCO 3 ) ingestion is commonplace. The individualized dose-response relationship between NaHCO 3 ingestion and blood biochemistry is unclear. The present study investigated the bicarbonate, pH, base excess and sodium responses to NaHCO 3 ingestion. Sixteen healthy males (23 ± 2 years; 78.6 ± 15.1 kg) attended three randomized order-balanced, nonblinded sessions, ingesting a single dose of either 0.1, 0.2 or 0.3 g·kg -1 BM of NaHCO 3 (Intralabs, UK). Fingertip capillary blood was obtained at baseline and every 10 min for 1 hr, then every 15 min for a further 2 hr. There was a significant main effect of both time and condition for all assessed blood analytes (p ≤ .001). Blood analyte responses were significantly lower following 0.1 g·kg -1 BM compared with 0.2 g·kg -1 BM; bicarbonate concentrations and base excess were highest following ingestion of 0.3 g·kg -1 BM (p ≤ .01). Bicarbonate concentrations and pH significantly increased from baseline following all doses; the higher the dose the greater the increase. Large interindividual variability was shown in the magnitude of the increase in bicarbonate concentrations following each dose (+2.0-5; +5.1-8.1; and +6.0-12.3 mmol·L -1 for 0.1, 0.2 and 0.3 g·kg -1 BM) and in the range of time to peak concentrations (30-150; 40-165; and 75-180 min for 0.1, 0.2 and 0.3 g·kg -1 BM). The variability in bicarbonate responses was not affected by normalization to body mass. These results challenge current practices relating to NaHCO 3 supplementation and clearly show the need for athletes to individualize their ingestion protocol and trial varying dosages before competition.

Considerations on absorbed dose estimates based on different β-dose point kernels in internal dosimetry

International Nuclear Information System (INIS)

Uchida, Isao; Yamada, Yasuhiko; Yamashita, Takashi; Okigaki, Shigeyasu; Oyamada, Hiyoshimaru; Ito, Akira.

1995-01-01

In radiotherapy with radiopharmaceuticals, more accurate estimates of the three-dimensional (3-D) distribution of absorbed dose is important in specifying the activity to be administered to patients to deliver a prescribed absorbed dose to target volumes without exceeding the toxicity limit of normal tissues in the body. A calculation algorithm for the purpose has already been developed by the authors. An accurate 3-D distribution of absorbed dose based on the algorithm is given by convolution of the 3-D dose matrix for a unit cubic voxel containing unit cumulated activity, which is obtained by transforming a dose point kernel into a 3-D cubic dose matrix, with the 3-D cumulated activity distribution given by the same voxel size. However, beta-dose point kernels affecting accurate estimates of the 3-D absorbed dose distribution have been different among the investigators. The purpose of this study is to elucidate how different beta-dose point kernels in water influence on the estimates of the absorbed dose distribution due to the dose point kernel convolution method by the authors. Computer simulations were performed using the MIRD thyroid and lung phantoms under assumption of uniform activity distribution of 32 P. Using beta-dose point kernels derived from Monte Carlo simulations (EGS-4 or ACCEPT computer code), the differences among their point kernels gave little differences for the mean and maximum absorbed dose estimates for the MIRD phantoms used. In the estimates of mean and maximum absorbed doses calculated using different cubic voxel sizes (4x4x4 mm and 8x8x8 mm) for the MIRD thyroid phantom, the maximum absorbed doses for the 4x4x4 mm-voxel were estimated approximately 7% greater than the cases of the 8x8x8 mm-voxel. They were found in every beta-dose point kernel used in this study. On the other hand, the percentage difference of the mean absorbed doses in the both voxel sizes for each beta-dose point kernel was less than approximately 0.6%. (author)

Analysis of workers' dose records from the Greek Dose Registry Information System

International Nuclear Information System (INIS)

Kamenopoulou, V.; Dimitriou, P.; Proukakis, Ch.

1995-01-01

The object of this work is the study of the individual film badge annual dose information of classified workers in Greece, monitored and assessed by the central dosimetry service of the Greek Atomic Energy Commission. Dose summaries were recorded and processed by the Dose Registry Information System. The statistical analysis refers to the years 1989-93 and deals with the distribution of individuals in the occupational groups, the mean annual dose, the collective dose, the distribution of the dose over the different specialties and the number of workers that have exceeded any of the established dose limits. Results concerning the annual dose summaries, demonstrate a year-by-year reduction in the mean individual dose to workers in the health sector. Conversely, exposures in the industrial sector did not show any decreasing tendency during the period under consideration. (Author)

The Time-Dose-Response Relationship for Elicitation of Contact Dermatitis in Isoeugenol Allergic Individuals

DEFF Research Database (Denmark)

Andersen, K. E.; Johansen, J. D.; Bruze, M.

2001-01-01

The elicitation response in allergic contact dermatitis is dose dependent, but the time-concentration relationship for elicitation has not previously been described. In this study 27 isoeugenol-sensitive patients participated in serial dilution patch tests with isoeugenol and a double-blinded Rep......The elicitation response in allergic contact dermatitis is dose dependent, but the time-concentration relationship for elicitation has not previously been described. In this study 27 isoeugenol-sensitive patients participated in serial dilution patch tests with isoeugenol and a double......-blinded Repeated Open Application Test (ROAT) using two concentrations of isoeugenol, 0.2 and 0.05%. Seven controls without isoeugenol allergy were also included. The participants applied 3.72 +/- 1.57 (mean +/- SD) mg/cm(2) of coded isoeugenol solutions twice a day to a 3 x 3 cm(2) area on the volar aspect...... of the right and left arm, respectively. For each test site the applications continued until a reaction appeared or for a maximum of 28 days. The minimal criteria for a positive reaction regarded as allergic contact dermatitis was persistent erythema at the ROAT test site. All controls were negative and 16...

Comparative evaluations of individual radiation doses at hospital environment in two decades 73-82 and 86-95

International Nuclear Information System (INIS)

Carreira, Mauricio Costa; Almeida, Adelaide de; Santos, Maria Concepta P.S.

1996-01-01

Individual radiation doses in two decades of Hospital das Clinicas, Ribeirao Preto, Sao Paulo State, Brazil, are analysed. The annual values are studied according to the hospital service and specific worker categories. The workers are classified in categories A or B as recommended by ICRP 35. Three types of individual monitors (film badges, Ca So 4 and Li F + Ca So 4 ) supplied by three distinct laboratories are compared

MONITORING OF INDIVIDUAL DOSES FOR MEDICAL WORKERS OF DENTAL POLYCLINIC’S X-RAY ROOMS IN DUSHANBE, THE REPUBLIC OF TADJIKISTAN

Directory of Open Access Journals (Sweden)

N. U. Hakimova

2016-01-01

Full Text Available The article presents the data and analyses of personnel’s average annual external exposure doses monitoring via the thermoluminescent dosimetry method used for X-ray radiological personnel in dental polyclinics of Dushanbe, Tadjikistan Republic over a 5-year period ( 2010–2014 . Out of 42 registered medical institutions dental polyclinics amounted up to only just 14%. For this work thermoluminescent dosimeters were used ( with LiF: Mg, Ti with the thermoluminescent dosimetric installation “ Harshaw – 4500” as the reader device. Monitoring results comparison of individual dose equivalent Hp ( 10 values was conducted for two groups of medical workers: medical doctors and X-ray lab technicians. It is demonstrated that radiological technicians’ professional exposure doses are on the average by 23% higher than those for medical doctors.The average individual exposure doses over the above indicated period amount to 0,93 mSv and 1,3 mSv for doctors and X-ray lab technicians, respectively, and are in the range from 0,45 mSv to 2,39 mSv. The doses include contribution from the natural background. The values of doses recorded for the personnel in dental polyclinic correspond to those recorded for the workers in the routine X-ray rooms.

Dose-to-medium vs. dose-to-water: Dosimetric evaluation of dose reporting modes in Acuros XB for prostate, lung and breast cancer

Directory of Open Access Journals (Sweden)

Suresh Rana

2014-12-01

Full Text Available Purpose: Acuros XB (AXB dose calculation algorithm is available for external beam photon dose calculations in Eclipse treatment planning system (TPS. The AXB can report the absorbed dose in two modes: dose-to-water (Dw and dose-to-medium (Dm. The main purpose of this study was to compare the dosimetric results of the AXB_Dm with that of AXB_Dw on real patient treatment plans. Methods: Four groups of patients (prostate cancer, stereotactic body radiation therapy (SBRT lung cancer, left breast cancer, and right breast cancer were selected for this study, and each group consisted of 5 cases. The treatment plans of all cases were generated in the Eclipse TPS. For each case, treatment plans were computed using AXB_Dw and AXB_Dm for identical beam arrangements. Dosimetric evaluation was done by comparing various dosimetric parameters in the AXB_Dw plans with that of AXB_Dm plans for the corresponding patient case. Results: For the prostate cancer, the mean planning target volume (PTV dose in the AXB_Dw plans was higher by up to 1.0%, but the mean PTV dose was within ±0.3% for the SBRT lung cancer. The analysis of organs at risk (OAR results in the prostate cancer showed that AXB_Dw plans consistently produced higher values for the bladder and femoral heads but not for the rectum. In the case of SBRT lung cancer, a clear trend was seen for the heart mean dose and spinal cord maximum dose, with AXB_Dw plans producing higher values than the AXB_Dm plans. However, the difference in the lung doses between the AXB_Dm and AXB_Dw plans did not always produce a clear trend, with difference ranged from -1.4% to 2.9%. For both the left and right breast cancer, the AXB_Dm plans produced higher maximum dose to the PTV for all cases. The evaluation of the maximum dose to the skin showed higher values in the AXB_Dm plans for all 5 left breast cancer cases, whereas only 2 cases had higher maximum dose to the skin in the AXB_Dm plans for the right breast cancer

Dose Estimates for Site Radiography outside the Border to the Premises

Energy Technology Data Exchange (ETDEWEB)

Tanzi, C. P.; Eleveld, H.

2004-07-01

Radiography with X-ray generators or sealed radioactive sources (e.g. cobalt-60 and iridium-192) is a well-established non-destructive technique for the detection of internal flaws in welds and castings. The quality of the weld during the fabrication of pressure vessels, pipelines, storage tanks and other engineering structures can thus be verified. Often radiography is performed in an adequately shielded enclosure, but it may be necessary to perform it on location (site radiography). Paradoxically, if measurements are performed with other employees present, the main beam might be directed away towards the border of the premises in order to minimise the exposure of the workers but thus increasing the potential exposure to the population. In all cases a clearly marked enclosure has to be defined, to which neither non-radiological workers nor members of the public can have access. During a testing period, the maximum allowed dose rate at this enclosure is 10 microSv in one hour (only in exceptional cases 40 microSv) in the Netherlands. In addition, the Decree on radiation protection (in Dutch: {sup B}esluit stralingsbescherming{sup e}stablishes a further limit per location of 100 microSv per year, and the duty of reporting when the number of 3300 recordings at any one site is reached. This number is based on the assumption of a multifunctional individual dose of 0.03 microSv per recording at the enclosure. This multifunctional individual dose is defined as the dose received of an individual who lives in the vicinity of the source or location; this is a conservative approach considering the fact that the area around an industrial site is usually not intended to be residential area. However, for radiography in the field, skyshine might be underestimated, good collimation of the beam might not be seen as a priority, and the required monitoring may be difficult to guarantee along all of the enclosure. Also, there is an increasing availability of commercial portable X

Dose Estimates for Site Radiography outside the Border to the Premises

International Nuclear Information System (INIS)

Tanzi, C. P.; Eleveld, H.

2004-01-01

Radiography with X-ray generators or sealed radioactive sources (e.g. cobalt-60 and iridium-192) is a well-established non-destructive technique for the detection of internal flaws in welds and castings. The quality of the weld during the fabrication of pressure vessels, pipelines, storage tanks and other engineering structures can thus be verified. Often radiography is performed in an adequately shielded enclosure, but it may be necessary to perform it on location (site radiography). Paradoxically, if measurements are performed with other employees present, the main beam might be directed away towards the border of the premises in order to minimise the exposure of the workers but thus increasing the potential exposure to the population. In all cases a clearly marked enclosure has to be defined, to which neither non-radiological workers nor members of the public can have access. During a testing period, the maximum allowed dose rate at this enclosure is 10 microSv in one hour (only in exceptional cases 40 microSv) in the Netherlands. In addition, the Decree on radiation protection (in Dutch: B esluit stralingsbescherming e stablishes a further limit per location of 100 microSv per year, and the duty of reporting when the number of 3300 recordings at any one site is reached. This number is based on the assumption of a multifunctional individual dose of 0.03 microSv per recording at the enclosure. This multifunctional individual dose is defined as the dose received of an individual who lives in the vicinity of the source or location; this is a conservative approach considering the fact that the area around an industrial site is usually not intended to be residential area. However, for radiography in the field, skyshine might be underestimated, good collimation of the beam might not be seen as a priority, and the required monitoring may be difficult to guarantee along all of the enclosure. Also, there is an increasing availability of commercial portable X-ray units

Dosimetric systems of high dose, dose rate and dose uniformity in food and medical products

International Nuclear Information System (INIS)

Vargas, J.; Vivanco, M.; Castro, E.

2014-08-01

In the Instituto Peruano de Energia Nuclear (IPEN) we use the chemical dosimetry Astm-E-1026 Fricke as a standard dosimetric system of reference and different routine dosimetric systems of high doses, according to the applied doses to obtain the desired effects in the treated products and the doses range determined for each type of dosimeter. Fricke dosimetry is a chemical dosimeter in aqueous solution indicating the absorbed dose by means an increase in absorbance at a specific wavelength. A calibrated spectrophotometer with controlled temperature is used to measure absorbance. The adsorbed dose range should cover from 20 to 400 Gy, the Fricke solution is extremely sensitive to organic impurities, to traces of metal ions, in preparing chemical products of reactive grade must be used and the water purity is very important. Using the referential standard dosimetric system Fricke, was determined to March 5, 2013, using the referential standard dosimetric system Astm-1026 Fricke, were irradiated in triplicate Fricke dosimeters, to 5 irradiation times (20; 30; 40; 50 and 60 seconds) and by linear regression, the dose rate of 5.400648 kGy /h was determined in the central point of the irradiation chamber (irradiator Gamma cell 220 Excel), applying the decay formula, was compared with the obtained results by manufacturers by means the same dosimetric system in the year of its manufacture, being this to the date 5.44691 kGy /h, with an error rate of 0.85. After considering that the dosimetric solution responds to the results, we proceeded to the irradiation of a sample of 200 g of cereal instant food, 2 dosimeters were placed at the lateral ends of the central position to maximum dose and 2 dosimeters in upper and lower ends as minimum dose, they were applied same irradiation times; for statistical analysis, the maximum dose rate was 6.1006 kGy /h and the minimum dose rate of 5.2185 kGy /h; with a dose uniformity of 1.16. In medical material of micro pulverized bone for

Assessment of maximum tolerated dose of a new herbal drug, Semelil (ANGIPARSTM in patients with diabetic foot ulcer: A Phase I clinical trial

Directory of Open Access Journals (Sweden)

Heshmat R

2008-04-01

Full Text Available Background and the purpose of the study: In many cases of diabetic foot ulcer (DFU management, wound healing is incomplete, and wound closure and epithelial junctional integrity are rarely achieved. Our aim was to evaluate the maximum tolerated dose (MTD and dose-limiting toxicity (DLT of Semelil (ANGIPARSTM, a new herbal compound for wound treatment in a Phase I clinical trial.Methods: In this open label study, six male diabetic patients with a mean age of 57±7.6 years were treated with escalating intravenous doses of Semelil, which started at 2 cc/day to 13.5 cc/day for 28 days. Patients were assessed with a full physical exam; variables which analyzed included age, past history of diabetes and its duration, blood pressure, body temperature, weight, characteristics of DFU, Na, K, liver function test, Complete Blood Count and Differential(CBC & diff, serum amylase, HbA1c, PT, PTT, proteinuria, hematuria, and side effects were recorded. All the measurements were taken at the beginning of treatment, the end of week 2 and week 4. We also evaluated Semelil's side effects at the end of weeks 4 and 8 after ending therapy.Results and major conclusions: Up to the drug dose of 10 cc/day foot ulcer dramatically improved. We did not observe any clinical or laboratory side effects at this or lower dose levels in diabetic patients. With daily dose of 13.5 cc of Semelil we observed phlebitis at the infusion site, which was the only side effect. Therefore, in this study we determined the MTD of Semelil at 10 cc/day, and the only DLT was phlebitis in injection vein. The recommended dose of Semelil I.V. administration for Phase II studies was 4 cc/day.

Patient radiation doses from neuroradiology procedures

Energy Technology Data Exchange (ETDEWEB)

Garcia-Roman, M J; Abreu-Luis, J; Hernandez-Armas, J [Servicio de Fisica Medica, Hospital Universitario de Canarias, La Laguna, Tenerife (Spain); Prada-Martinez, E [Servicio de Radiodiagnostico, Hospital Universitario de Canarias, La Laguna, Tenerife (Spain)

2001-03-01

Following the presentation of radiation-induced deterministic effects by some patients undergoing neuroradiological procedures during successive sessions, such as temporary epilation, in the 'Hospital Universitario de Canarias', measurements were made of dose to patients. The maximum dose-area product measured by ionization chamber during these procedures was 39617 cGy.cm{sup 2} in a diagnostic of aneurysm and the maximum dose to the skin measured by thermoluminescent dosemeters (TLDs) was 462.53 mGy. This can justify certain deterministic effects but it is unlikely that the patients will suffer serious effects from this skin dose. Also, measurements were made of effective dose about two usual procedures, embolisation of tumour und embolisation of aneurysm. These procedures were reproduced with an anthropomorphic phantom Rando and doses were measured with TLDs. Effective doses obtained were 3.79 mSv and 4.11 mSv, respectively. The effective dose valued by the program EFFDOSE was less than values measured with TLDs. (author)

Patient radiation doses from neuroradiology procedures

International Nuclear Information System (INIS)

Garcia-Roman, M.J.; Abreu-Luis, J.; Hernandez-Armas, J.; Prada-Martinez, E.

2001-01-01

Following the presentation of radiation-induced deterministic effects by some patients undergoing neuroradiological procedures during successive sessions, such as temporary epilation, in the 'Hospital Universitario de Canarias', measurements were made of dose to patients. The maximum dose-area product measured by ionization chamber during these procedures was 39617 cGy.cm 2 in a diagnostic of aneurysm and the maximum dose to the skin measured by thermoluminescent dosemeters (TLDs) was 462.53 mGy. This can justify certain deterministic effects but it is unlikely that the patients will suffer serious effects from this skin dose. Also, measurements were made of effective dose about two usual procedures, embolisation of tumour und embolisation of aneurysm. These procedures were reproduced with an anthropomorphic phantom Rando and doses were measured with TLDs. Effective doses obtained were 3.79 mSv and 4.11 mSv, respectively. The effective dose valued by the program EFFDOSE was less than values measured with TLDs. (author)

Radiation dose in dental radiology

International Nuclear Information System (INIS)

Cohnen, M.; Kemper, J.; Moedder, U.; Moebes, O.; Pawelzik, J.

2002-01-01

The aim of this study was to compare radiation exposure in panoramic radiography (PR), dental CT, and digital volume tomography (DVT). An anthropomorphic Alderson-Rando phantom and two anatomical head phantoms with thermoluminescent dosimeters fixed at appropriate locations were exposed as in a dental examination. In PR and DVT, standard parameters were used while variables in CT included mA, pitch, and rotation time. Image noise was assessed in dental CT and DVT. Radiation doses to the skin and internal organs within the primary beam and resulting from scatter radiation were measured and expressed as maximum doses in mGy. For PR, DVT, and CT, these maximum doses were 0.65, 4.2, and 23 mGy. In dose-reduced CT protocols, radiation doses ranged from 10.9 to 6.1 mGy. Effective doses calculated on this basis showed values below 0.1 mSv for PR, DVT, and dose-reduced CT. Image noise was similar in DVT and low-dose CT. As radiation exposure and image noise of DVT is similar to low-dose CT, this imaging technique cannot be recommended as a general alternative to replace PR in dental radiology. (orig.)

Dose implications of adopting the CAC [Codex Alimentarius Commission] standard for the control of food in Hong Kong

International Nuclear Information System (INIS)

Poon, C.B.; Au, S.M.

1997-01-01

Based on several assumptions on food consumption and contamination, the dose implication in using the Codex Alimentarius Commission (CAC) standard for the control of food in Hong Kong following a nuclear accident has been studied. Calculations are performed on six likely contaminated food types and on three radionuclide groups. Results show that the maximum individual doses arisig from the ingestion pathway are most probably below 0.2 mSv. This dose is so low that it would not cause any serious health problem to the people of Hong Kong. (author)

The survey of the surface doses of the dental x-ray machines

International Nuclear Information System (INIS)

Lee, Jae Seo; Kang, Byung Cheol; Yoon, Suk Ja

2005-01-01

The purpose of this study was to investigate variability of doses with same exposure parameters and evaluate radiographic density according to the variability of doses. Twenty-eight MAX-GLS (Shinhung Co, Seoul, Korea), twenty-one D-60-S (DongSeo Med, Seoul, Korea), and eleven REX-601 (Yoshida Dental MFG, Tokyo, Japan) dental x-ray machines were selected for this study. Surface doses were measured under selected combinations of tube voltage, tube current, exposure time, and constant distance 42 cm from the focal spot to the surface of the Multi-O-meter (Unfors Instrument, Billdal, Sweden). Radiographic densities were measured on the films at maximum, minimum and mean surface doses of each brand of x-ray units. With MAX-GLS, the maximum surface doses were thirteen to fourteen times as much as the minimum surfaces doses. With D-60-S, the maximum surface doses were three to eight times as much as the minimum surface doses. With REX-601, the maximum surface doses were six to ten times as much as the minimum surface doses. The differences in radiographic densities among maximum, mean, and minimum doses were significant (p<0.01). The surface exposure doses of each x-ray machine at the same exposure parameters were different within the same manufacturer's machines.

Individual Genetic Susceptibility

International Nuclear Information System (INIS)

Hall, Eric J.

2008-01-01

Risk estimates derived from epidemiological studies of exposed populations, as well as the maximum permissible doses allowed for occupational exposure and exposure of the public to ionizing radiation are all based on the assumption that the human population is uniform in its radiosensitivity, except for a small number of individuals, such as ATM homozygotes who are easily identified by their clinical symptoms. The hypothesis upon which this proposal is based is that the human population is not homogeneous in radiosensitiviry, but that radiosensitive sub-groups exist which are not easy to identify. These individuals would suffer an increased incidence of detrimental radiation effects, and distort the shape of the dose response relationship. The radiosensitivity of these groups depend on the expression levels of specific proteins. The plan was to investigate the effect of 3 relatively rare, high penetrate genes available in mice, namely Atm, mRad9 and Brca1. The purpose of radiation protection is to prevent deterministic effects of clinical significance and limit stochastic effects to acceptable levels. We plan, therefore to compare with wild type animals the radiosensitivity of mice heterozygous for each of the genes mentioned above, as well as double heterozygotes for pairs of genes, using two biological endpoints: (a) Ocular cataracts as an important and relevant deterministic effect, and (b) Oncogenic transformation in cultured embryo fibroblasts, as a surrogate for carcinogenesis, the most relevant stochastic effect.

Dose estimation and radiation control measures for individuals having close contact with patients administered in vivo nuclear medicine

International Nuclear Information System (INIS)

Konishi, E.; Abe, K.; Kusama, T.

1993-01-01

Patients who have been administered radiopharmaceuticals become a source of exposure to a non-occupational individual helping in support and comfort of these patients. We measured external dose rates at several distances from 84 adult patients administered radiopharmaceuticals, and urinary excretion of radioactivity in their patients. And we estimated the maximal dose for persons having close contact with patients administered radiopharmaceuticals from the combination of these measurement data and scenarios of contact with patients. On the basis of the estimated values, we proposed the following dose constraint for care givers. (1) The dose constraint for a non-occupational care givers to an adult nuclear medicine patient should in no case exceed 300 μSv per patient per examination of any kind. (2) The dose constraint in ordinary examinations employing a radionuclide should not be greater than 15 μSv per patient per examination. (3 tabs.)

Reducing radiation dose in 64-row spiral CT coronary angiography: study based on individualized scan dosage protocol

International Nuclear Information System (INIS)

Kang Deqiang; Zhao Jing; Peng Nan; Hua Haiqin; Li Chao; Guo Ying; Shen Yun

2012-01-01

Objective: To investigate the methods of reducing radiation dose in CT coronary angiography through optimizing individualized scan dosage protocol. Methods: Two hundred patients (group A) underwent coronary CTA examination which was performed with fixed 120 kV and variable mA according to their BMI. The mA was set as 150-300 mA (BMI < 18.5 kg/m2), 300-500 mA (18.5 kg/m 2 ≤ BMI < 25.0 kg/m 2 ), and 500-800 mA (BMI ≥ 25.0 kg/m 2 ). When all examinations were finished, a linear regression was employed to analyze the correlation between mA and BMI, body surface (Suf), image noise (SD) respectively. The results of the analysis were used to formulate a regression equation, which was further used to establish a table list for quick search on how much mA that individualized coronary CTA scan would need. Another 200 patients (group B) enrolled for the individualized scan were scanned under new protocol that previous study established. The tube voltage was 100 and 120 kV. The tube current was variable according to the data in the table list. One-way ANOVA and Kruskal-wallis H test were used for statistics. Results: Regression equation between mA and BMI, Suf, SD was: mA =17.984 × BMI + 169.149 × Suf-2.282 × SD-361.039. The SD (group A: 32.08 ± 5.80, group B: 28.60±4.47), dose index volume (CTDI vol ) [group A: (41.97 ± 11.37) mGy, group B: (33.18±10.07) mGy], effective dose(ED) [group A: (10.91 ±3.07) mSy, group B: (8.83 ±2.72)mSv] had significant differences between the two groups (F=43.45, 63.71, 49.07 respectively, P<0.01 for all). The SD and ED results obtained in group B were better than those in group A. Conclusion: Better performances were obtained when BMI combined Suf was used as a new individualized protocol than when BMI was used only, which means good image quality and lower radiation dosage in coronary CTA examination. (authors)

Biphasic dose responses in biology, toxicology and medicine: Accounting for their generalizability and quantitative features

International Nuclear Information System (INIS)

Calabrese, Edward J.

2013-01-01

The most common quantitative feature of the hormetic-biphasic dose response is its modest stimulatory response which at maximum is only 30–60% greater than control values, an observation that is consistently independent of biological model, level of organization (i.e., cell, organ or individual), endpoint measured, chemical/physical agent studied, or mechanism. This quantitative feature suggests an underlying “upstream” mechanism common across biological systems, therefore basic and general. Hormetic dose response relationships represent an estimate of the peak performance of integrative biological processes that are allometrically based. Hormetic responses reflect both direct stimulatory or overcompensation responses to damage induced by relatively low doses of chemical or physical agents. The integration of the hormetic dose response within an allometric framework provides, for the first time, an explanation for both the generality and the quantitative features of the hormetic dose response. -- Highlights: •The hormetic stimulation is at maximum 30–60% greater than control responses. •Hormesis is a measure of biological performance and plasticity. •The hormetic response is evolutionary based and highly generalizable. -- This paper provides a biologically based explanation for the generalizability/quantitative features of the hormetic dose response, representing a fundamental contribution to the field

Application of maximum radiation exposure values and monitoring of radiation exposure

International Nuclear Information System (INIS)

1996-01-01

The guide presents the principles to be applied in calculating the equivalent dose and the effective dose, instructions on application of the maximum values for radiation exposure, and instruction on monitoring of radiation exposure. In addition, the measurable quantities to be used in monitoring the radiation exposure are presented. (2 refs.)

Collection and use of individual behavioral and consumption rate data to improve reconstruction of thyroid doses from nuclear weapons tests in Kazakhstan

International Nuclear Information System (INIS)

Drozdovitch, Vladimir; Schonfeld, Sara; Bouville, Andre; Land, Charles; Luckyanov, Nick; Simon, Steven L.; Schwerin, Michael

2008-01-01

Full text: Historical behavioral and consumption rate data were collected from residents of Kazakhstan exposed to nuclear weapons testing fallout using a focus group data collection strategy. These data will enable improved thyroid dose estimation in a radiation epidemiological study being carried out the U.S. National Cancer Institute. The study on the relationship of radiation exposure from weapons testing fallout and thyroid disease in a cohort of 2,994 subjects is now in a stage of improving earlier dose estimates based on individual information collected from a basic questionnaire administered to the study population in 1998. The study subjects of both Kazakh and Russian origin were exposed during childhood to radioactive fallout from nuclear weapons tests conducted at the Semipalatinsk Nuclear Test Site between 1949 and 1962. Due to the long time since exposure, a well developed strategy is necessary to encourage accurate memory recall. Limitations of the data collected in 1998 suggested the need to obtain reliable information that is tailored specific to the requirements of the dose reconstruction algorithm and to the evaluation of individual dose uncertainties. Focus group data collection in Kazakhstan in 2007 involved four 8-person focus groups (three of women and one of men) in each of four exposed settlements where thyroid disease screening was conducted in 1998. Age-specific data on relevant childhood behaviour, including time spent indoors and consumption of milk and other dairy products from cows, goats, horses, and sheep, were collected from women's groups. Men's focus groups were interviewed about construction materials of houses and schools as well as animal grazing patterns and supplemental feed to animals. Information obtained from the focus groups are being used to derive the settlement-, ethnicity-, age-, and gender-specific (where appropriate) probability density distributions on individual consumption rates of milk and dairy products

Individual fluorouracil dose adjustment in FOLFOX based on pharmacokinetic follow-up compared with conventional body-area-surface dosing: a phase II, proof-of-concept study.

Science.gov (United States)

Capitain, Olivier; Asevoaia, Andreaa; Boisdron-Celle, Michele; Poirier, Anne-Lise; Morel, Alain; Gamelin, Erick

2012-12-01

To compare the efficacy and safety of pharmacokinetically (PK) guided fluorouracil (5-FU) dose adjustment vs. standard body-surface-area (BSA) dosing in a FOLFOX (folinic acid, fluorouracil, oxaliplatin) regimen in metastatic colorectal cancer (mCRC). A total of 118 patients with mCRC were administered individually determined PK-adjusted 5-FU in first-line FOLFOX chemotherapy. The comparison arm consisted of 39 patients, and these patients were also treated with FOLFOX with 5-FU by BSA. For the PK-adjusted arm 5-FU was monitored during infusion, and the dose for the next cycle was based on a dose-adjustment chart to achieve a therapeutic area under curve range (5-FU(ODPM Protocol)). The objective response rate was 69.7% in the PK-adjusted arm, and median overall survival and median progression-free survival were 28 and 16 months, respectively. In the traditional patients who received BSA dosage, objective response rate was 46%, and overall survival and progression-free survival were 22 and 10 months, respectively. Grade 3/4 toxicity was 1.7% for diarrhea, 0.8% for mucositis, and 18% for neutropenia in the dose-monitored group; they were 12%, 15%, and 25%, respectively, in the BSA group. Efficacy and tolerability of PK-adjusted FOLFOX dosing was much higher than traditional BSA dosing in agreement with previous reports for 5-FU monotherapy PK-adjusted dosing. Analysis of these results suggests that PK-guided 5-FU therapy offers added value to combination therapy for mCRC. Copyright © 2012 Elsevier Inc. All rights reserved.

Inter-Individual Variability in Human Response to Low-Dose Ionizing Radiation, Final Report

International Nuclear Information System (INIS)

Rocke, David

2016-01-01

In order to investigate inter-individual variability in response to low-dose ionizing radiation, we are working with three models, 1) in-vivo irradiated human skin, for which we have a realistic model, but with few subjects, all from a previous project, 2) ex-vivo irradiated human skin, for which we also have a realistic model, though with the limitations involved in keeping skin pieces alive in media, and 3) MatTek EpiDermFT skin plugs, which provides a more realistic model than cell lines, which is more controllable than human samples.

Inter-Individual Variability in Human Response to Low-Dose Ionizing Radiation, Final Report

Energy Technology Data Exchange (ETDEWEB)

Rocke, David [Univ. of California, Davis, CA (United States)

2016-08-01

In order to investigate inter-individual variability in response to low-dose ionizing radiation, we are working with three models, 1) in-vivo irradiated human skin, for which we have a realistic model, but with few subjects, all from a previous project, 2) ex-vivo irradiated human skin, for which we also have a realistic model, though with the limitations involved in keeping skin pieces alive in media, and 3) MatTek EpiDermFT skin plugs, which provides a more realistic model than cell lines, which is more controllable than human samples.

Human Dose-Response Data for Francisella tularensis and a Dose- and Time-Dependent Mathematical Model of Early-Phase Fever Associated with Tularemia After Inhalation Exposure.

Science.gov (United States)

McClellan, Gene; Coleman, Margaret; Crary, David; Thurman, Alec; Thran, Brandolyn

2018-04-25

Military health risk assessors, medical planners, operational planners, and defense system developers require knowledge of human responses to doses of biothreat agents to support force health protection and chemical, biological, radiological, nuclear (CBRN) defense missions. This article reviews extensive data from 118 human volunteers administered aerosols of the bacterial agent Francisella tularensis, strain Schu S4, which causes tularemia. The data set includes incidence of early-phase febrile illness following administration of well-characterized inhaled doses of F. tularensis. Supplemental data on human body temperature profiles over time available from de-identified case reports is also presented. A unified, logically consistent model of early-phase febrile illness is described as a lognormal dose-response function for febrile illness linked with a stochastic time profile of fever. Three parameters are estimated from the human data to describe the time profile: incubation period or onset time for fever; rise time of fever; and near-maximum body temperature. Inhaled dose-dependence and variability are characterized for each of the three parameters. These parameters enable a stochastic model for the response of an exposed population through incorporation of individual-by-individual variability by drawing random samples from the statistical distributions of these three parameters for each individual. This model provides risk assessors and medical decisionmakers reliable representations of the predicted health impacts of early-phase febrile illness for as long as one week after aerosol exposures of human populations to F. tularensis. © 2018 Society for Risk Analysis.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus—the ‘D-shuttle’ project—

International Nuclear Information System (INIS)

Adachi, N; Adamovitch, V; Adjovi, Y; Antonietti, H; Arkoun, G; Blanchard, M; Aida, K; Akamatsu, H; Akiyama, S; Akli, A; Bernard, E; Ando, A; Andrault, T; Ayrault, D; Anzai, S; Avenoso, C; Bernardini, L; Berthet, E; Banasiewicz, M; Banaśkiewicz, M

2016-01-01

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter ‘D-shuttle’ for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries. (paper)

Radiation-induced rib fracture after stereotactic body radiotherapy with a total dose of 54-56 Gy given in 9-7 fractions for patients with peripheral lung tumor: impact of maximum dose and fraction size.

Science.gov (United States)

Aoki, Masahiko; Sato, Mariko; Hirose, Katsumi; Akimoto, Hiroyoshi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Ono, Shuichi; Takai, Yoshihiro

2015-04-22

Radiation-induced rib fracture after stereotactic body radiotherapy (SBRT) for lung cancer has been recently reported. However, incidence of radiation-induced rib fracture after SBRT using moderate fraction sizes with a long-term follow-up time are not clarified. We examined incidence and risk factors of radiation-induced rib fracture after SBRT using moderate fraction sizes for the patients with peripherally located lung tumor. During 2003-2008, 41 patients with 42 lung tumors were treated with SBRT to 54-56 Gy in 9-7 fractions. The endpoint in the study was radiation-induced rib fracture detected by CT scan after the treatment. All ribs where the irradiated doses were more than 80% of prescribed dose were selected and contoured to build the dose-volume histograms (DVHs). Comparisons of the several factors obtained from the DVHs and the probabilities of rib fracture calculated by Kaplan-Meier method were performed in the study. Median follow-up time was 68 months. Among 75 contoured ribs, 23 rib fractures were observed in 34% of the patients during 16-48 months after SBRT, however, no patients complained of chest wall pain. The 4-year probabilities of rib fracture for maximum dose of ribs (Dmax) more than and less than 54 Gy were 47.7% and 12.9% (p = 0.0184), and for fraction size of 6, 7 and 8 Gy were 19.5%, 31.2% and 55.7% (p = 0.0458), respectively. Other factors, such as D2cc, mean dose of ribs, V10-55, age, sex, and planning target volume were not significantly different. The doses and fractionations used in this study resulted in no clinically significant rib fractures for this population, but that higher Dmax and dose per fraction treatments resulted in an increase in asymptomatic grade 1 rib fractures.

Preliminary results on food consumption rates for off-site dose calculation of nuclear power plants

International Nuclear Information System (INIS)

Lee, Gab Bock; Chung, Yang Geun; Bang, Sun Young; Kang, Duk Won

2005-01-01

The Internal dose by food consumption mostly account for radiological dose of public around nuclear power plants(NPP). But, food consumption rate applied to off-site dose calculation in Korea which is the result of field investigation around Kori NPP by the KAERI in 1988. is not reflected of the latest dietary characteristics. The Ministry of Health and Welfare Affairs has investigated the food and nutrition of nations every 3 years based on the Law of National Health Improvement. To update the food consumption rates of the maximum individual, the analysis of the national food investigation results and field surveys around nuclear power plant sites have been carried out

Effective dose of individuals from the surrounding public to the facilities of the Abadia de Goiás radioactive waste disposal

International Nuclear Information System (INIS)

Ribeiro, E.; Borges, A.F. de Almeida; Camargos, K.M.; Santos, E.E. dos; Correa, R. da S.; Ferreira, N.C.; Ribeiro, N.V.

2017-01-01

The study presents the level of effective annual dose that individuals from the public - surrounding the repository of wastes with Cs-137, located in Abadia de Goiás, GO, Brazil - have received, according to analyzes carried out from June 2015 to July 2016. It was considered reference to the annual effective radiation dose limit of 0.3 mSv / year established by the National Nuclear Energy Commission (CNEN) for the impact of repositories on individuals in the public. Cs-137 activity determinations were performed on samples of surface water (ASU), groundwater (ASB), river bottom sediments (SED), soil (SOL) and vegetation (VEG). With these results, the effective doses were estimated for ASU and BSA consumption of 6.64 x 10 -4 mSv / year and for SED exposure, 3.92 x 10 - 6 mSv / year and for ASB use, 6.22 x 10 -3 mSv / year. For SOL and VEG, activity values of Cs-137 were used as indicators of contamination. It was observed that the effective annual doses were below the limit established by the norms, which can be inferred that the installation has been operating safely, without causing a radiological impact to the environment and individuals of the public

The 1st Nuclear Test in the former USSR of 29 August 1949: Comparison of individual dose estimates by modeling with EPR retrospective dosimetry and luminescence retrospective dosimetry data for Dolon village, Kazakhstan

Energy Technology Data Exchange (ETDEWEB)

Stepanenko, V.F. [Medical Radiological Research Center of RAMS, 4 Korolev Str., Obninsk 249036 (Russian Federation); Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan)], E-mail: mrrc@obninsk.ru; Hoshi, M. [Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Ivannikov, A.I. [Medical Radiological Research Center of RAMS, 4 Korolev Str., Obninsk 249036 (Russian Federation); Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Bailiff, I.K. [Luminescence Dating and Dosimetry Laboratory, University of Durham, South Road, Durham, DHI 3LE (United Kingdom); Zhumadilov, K. [Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Skvortsov, V.G. [Medical Radiological Research Center of RAMS, 4 Korolev Str., Obninsk 249036 (Russian Federation); Argembaeva, R. [Scientifical Research Institute for Radiation Medicine, 258, Gagarina Str., P.B. 49, Semipalatinsk 490026 (Kazakhstan); Tsyb, A.F. [Medical Radiological Research Center of RAMS, 4 Korolev Str., Obninsk 249036 (Russian Federation)

2007-07-15

Three methods of individual dose reconstruction, namely dose calculations based on the available archive data and on the individual questioning of inhabitants, EPR dosimetry in human tooth enamel, and retrospective luminescence dosimetry (RLD) with quartz inclusions in the bricks were applied for assessment of accumulated external doses in Dolon village (Kazakhstan), which is one of the most affected settlements as a result of 29.08.1949 nuclear test at Semipalatinsk nuclear test site. Dose values obtained by EPR and RLD methods were compared with computed dose values. The available data on soil contamination with {sup 137}Cs and {sup 239+240}Pu in the vicinity and inside Dolon village were used for interpretation of the results of comparison. Based on a calculated value of 2260 mGy for the dose in the air along the central axis of the trace located NW of Dolon, the doses in the air over whole village and for the south-eastern part of the village containing the RLD sampling points were estimated as 775{+-}40 and 645{+-}70mGy, respectively, the latter correlates well with the RLD dose value of 460{+-}92mGy. The 'upper level' of the mean 'shielding and behavior' factor of dose reduction for inhabitants of Dolon village was estimated as 0.28{+-}0.07; this was performed by comparing the individual EPR tooth enamel doses with the calculated mean dose for the settlement. The individual dose estimates by EPR dosimetry were compared with individual dose values obtained by modeling. Uncertainties of the calculated individual doses were evaluated using Monte Carlo simulations. The individual dose estimates by EPR method are lower in comparison with mean computed doses and with RLD data, but they are in a good consistency with computed individual dose values in Dolon village based on the results of individual questioning with account of individual 'shielding and behavior' factors.

The 1st Nuclear Test in the former USSR of 29 August 1949: Comparison of individual dose estimates by modeling with EPR retrospective dosimetry and luminescence retrospective dosimetry data for Dolon village, Kazakhstan

International Nuclear Information System (INIS)

Stepanenko, V.F.; Hoshi, M.; Ivannikov, A.I.; Bailiff, I.K.; Zhumadilov, K.; Skvortsov, V.G.; Argembaeva, R.; Tsyb, A.F.

2007-01-01

Three methods of individual dose reconstruction, namely dose calculations based on the available archive data and on the individual questioning of inhabitants, EPR dosimetry in human tooth enamel, and retrospective luminescence dosimetry (RLD) with quartz inclusions in the bricks were applied for assessment of accumulated external doses in Dolon village (Kazakhstan), which is one of the most affected settlements as a result of 29.08.1949 nuclear test at Semipalatinsk nuclear test site. Dose values obtained by EPR and RLD methods were compared with computed dose values. The available data on soil contamination with 137 Cs and 239+240 Pu in the vicinity and inside Dolon village were used for interpretation of the results of comparison. Based on a calculated value of 2260 mGy for the dose in the air along the central axis of the trace located NW of Dolon, the doses in the air over whole village and for the south-eastern part of the village containing the RLD sampling points were estimated as 775±40 and 645±70mGy, respectively, the latter correlates well with the RLD dose value of 460±92mGy. The 'upper level' of the mean 'shielding and behavior' factor of dose reduction for inhabitants of Dolon village was estimated as 0.28±0.07; this was performed by comparing the individual EPR tooth enamel doses with the calculated mean dose for the settlement. The individual dose estimates by EPR dosimetry were compared with individual dose values obtained by modeling. Uncertainties of the calculated individual doses were evaluated using Monte Carlo simulations. The individual dose estimates by EPR method are lower in comparison with mean computed doses and with RLD data, but they are in a good consistency with computed individual dose values in Dolon village based on the results of individual questioning with account of individual 'shielding and behavior' factors

Results of neutron dose measurements at the Rossendorf research reactors taking the actual neutron spectra into account

International Nuclear Information System (INIS)

Rimpler, A.; Kneschke, H.

1985-01-01

Based on a systematic evaluation of area dose studies at the beginning of the seventies, no individual routine neutron monitoring has been performed at the Rossendorf research reactors. To check this decision, a limited number of persons has been monitored with solid-state nuclear track detectors for several years. The dosemeters were calibrated on the basis of neutron spectra determined at the working places by means of the Bonner sphere method. Intermediate neutrons with a 1/E/sup α/ Fermi distribution were dominating. The fraction of fast neutrons was practically negligible. The obtained spectra, radiation, field quantities and results of individual dose measurements are presented. The dosemeter most appropriate for such neutron fields would be a 12-inch Bonner sphere rem counter. As the mean annual neutron exposure of research workers at the reactor amounted to only 2% of the maximum permissible dose, individual routine monitoring will, also in the future, not be neccessary. (author)

Pegylated interferon fractal pharmacokinetics: individualized dosing for hepatitis C virus infection.

Science.gov (United States)

Jain, Mamta K; Pasipanodya, Jotam G; Alder, Lara; Lee, William M; Gumbo, Tawanda

2013-03-01

Despite recent advances in hepatitis C virus (HCV) therapeutics, the combination of pegylated interferon and ribavirin (PEGIFN/RBV) remains the cornerstone of treatment. Optimization and individualization of PEGIFN dosing could improve outcomes. Week one PEGIFN serum concentrations in 42 HCV genotype 1-infected patients treated with conventional PEGIFN/RBV were analyzed using multicompartmental pharmacokinetic models. For each patient, pharmacokinetic parameter estimates, weight, age, interleukin-28B (IL-28B) single-nucleotide polymorphism, CD4 count, baseline HCV RNA, gender, race, and HIV status were examined using classification and regression tree analysis to identify factors predictive of sustained viral response (SVR). Survival analysis was performed to compare the time to undetectable viral load in patients with and without the highest scoring predictor. PEGIFN concentrations varied at least 87-fold. Pharmacokinetics were best described by a two-compartment model with an 8.4-h absorption lag. Patient weight correlated with PEGIFN systemic clearance based on fractal geometry relationships. SVR was achieved in 36% of patients; a PEGIFN cumulative 1-week area under the curve (AUC) of ≤0.79 mg · h/liter scored highest in predicting poor response, followed by a weight of ≥93.7 kg. Patients with a PEGIFN AUC of >0.79 mg · h/liter achieved undetectable viral load more rapidly than those with a lower AUC (hazard ratio, 1.63; 95% confidence interval, 1.21 to 2.04). PEGIFN exhibits wide pharmacokinetic variability, mainly driven by patient weight, so that the standard dose may not reach levels needed to achieve SVR. Optimizing dose to patient weight and PEGIFN AUC in the first week offers a solution to improve SVR and to potentially shorten duration of therapy.

PRODUTIVIDADE DE CAPIM-MOMBAÇA (Panicum maximum, COM DIFERENTES DOSES DE BIOFERTILIZANTE / MOMBAÇA GRASS PRODUCTIVITY (Panicum maximum, WITH DIFFERENT DOSES OF BIOFERTILIZER

Directory of Open Access Journals (Sweden)

A. Simonetti

2016-03-01

Full Text Available O presente estudo teve por objetivo verificar a influência da aplicação do dejeto de bovino leiteiro tratados em biodigestores anaeróbios, na forma de biofertilizante, sobre a produtividade da capim Mombaça, em condições de sequeiro.  O trabalho foi conduzido no Instituto de Biotecnologia – IBIOTEC, pertencente à UNIARA, Araraquara – SP. Para obtenção do biofertilizante, foi feita a diluição dos dejetos em água e armazenado em um biodigestor modelo indiano de fibra de vidro com capacidade útil de 1000 L, instalado no referido instituto. As fertilizações foram feitas a lanço após cada rebaixamento das parcelas. O delineamento utilizado foi em blocos casualizados, com quatro tratamentos e quatro repetições, com diferentes doses do biofertilizante, sendo: 0; 50m³; 100m³ e 200m³/ha-1.  As variáveis avaliadas foram: altura, produção por hectare (matéria seca e matéria verde, e qualidade bromatológica. Foram observados que os tratamentos que receberam a maior dosagem de biofertilizante, apresentaram maiores valores para produtividade Matéria Seca, Matéria Verde e teor de proteína. Conclui-se que a aplicação de biofertilizante é benéfico ao sistema de pastagem, porém suas doses devem ser estudadas e a sua resposta na produção pode obtidas a longo prazo.

Influence of the Target Vessel on the Location and Area of Maximum Skin Dose during Percutaneous Coronary Intervention

International Nuclear Information System (INIS)

Chida, K.; Fuda, K.; Kagaya, Y.; Saito, H.; Takai, Y.; Kohzuki, M.; Takahash i, S.; Yamada, S.; Zuguchi, M.

2007-01-01

Background: A number of cases involving radiation-associated patient skin injury attributable to percutaneous coronary intervention (PCI) have been reported. Knowledge of the location and area of the patient's maximum skin dose (MSD) in PCI is necessary to reduce the risk of skin injury. Purpose: To determine the location and area of the MSD in PCI, and separately analyze the effects of different target vessels. Material and Methods: 197 consecutive PCI procedures were studied, and the location and area of the MSD were calculated by a skin-dose mapping software program: Caregraph. The target vessels of the PCI procedures were divided into four groups based on the American Heart Association (AHA) classification. Results: The sites of the MSD for AHA no.1-3, AHA no.4, and AHA no.11-15 were located mainly on the right back skin, the lower right or center back skin, and the upper back skin areas, respectively, whereas the MSD sites for the AHA no. 5-10 PCI were widely spread. The MSD area for the AHA no. 4 PCI was larger than that for the AHA no. 11-15 PCI (P<0.0001). Conclusion: Although the radiation associated with PCI can be widely spread and variable, we observed a tendency regarding the location and area of the MSD when we separately analyzed the data for different target vessels. We recommend the use of a smaller radiation field size and the elimination of overlapping fields during PCI

Individualized Hydrocodone Therapy Based on Phenotype, Pharmacogenetics, and Pharmacokinetic Dosing.

Science.gov (United States)

Linares, Oscar A; Fudin, Jeffrey; Daly, Annemarie L; Boston, Raymond C

2015-12-01

(1) To quantify hydrocodone (HC) and hydromorphone (HM) metabolite pharmacokinetics with pharmacogenetics in CYP2D6 ultra-rapid metabolizer (UM), extensive metabolizer (EM), and poor metabolizer (PM) metabolizer phenotypes. (2) To develop an HC phenotype-specific dosing strategy for HC that accounts for HM production using clinical pharmacokinetics integrated with pharmacogenetics for patient safety. In silico clinical trial simulation. Healthy white men and women without comorbidities or history of opioid, or any other drug or nutraceutical use, age 26.3±5.7 years (mean±SD; range, 19 to 36 y) and weight 71.9±16.8 kg (range, 50 to 108 kg). CYP2D6 phenotype-specific HC clinical pharmacokinetic parameter estimates and phenotype-specific percentages of HM formed from HC. PMs had lower indices of HC disposition compared with UMs and EMs. Clearance was reduced by nearly 60% and the t1/2 was increased by about 68% compared with EMs. The canonical order for HC clearance was UM>EM>PM. HC elimination mainly by the liver, represented by ke, was reduced about 70% in PM. However, HC's apparent Vd was not significantly different among UMs, EMs, and PM. The canonical order of predicted plasma HM concentrations was UM>EM>PM. For each of the CYP2D6 phenotypes, the mean predicted HM levels were within HM's therapeutic range, which indicates HC has significant phenotype-dependent pro-drug effects. Our results demonstrate that pharmacogenetics afford clinicians an opportunity to individualize HC dosing, while adding enhanced opportunity to account for its conversion to HM in the body.

Dose distributions of pendulum fields in the field border plane

International Nuclear Information System (INIS)

Schrader, R.

1986-01-01

Calculations (program SIDOS-U2) and LiF measurements taken in a cylindric water phantom are used to investigate the isodose distributions of different pendulum irradiation methods (Co-60) in a plane which is parallel to the central ray plane and crosses the field borders at the depth of the axis. The dose values compared to the maximum values of the central ray plane are completely different for each pendulum method. In case of monoaxial pendulum methods around small angles, the maximum dose value found in the border plane is less than 50% of the dose in the central ray plane. The relative maximum of the border plane moves to tissues laying in a greater depth. In case of bi-axial methods, the maximum value of the border plane can be much more than 50% of the maximum dose measured in the central ray plane. (orig.) [de

Methods of assessment of individual and collective doses to transport workers and members of the public during the transport of radioactive material

International Nuclear Information System (INIS)

Vohra, K.G.; Subrahmanian, G.; Nandakumar, A.N.; Kher, R.K.; Iyer, S.R.K.

1986-01-01

Transport workers handling radioactive cargoes are generally exposed to the highest dose rates of any population group. Methods of assessment of dose received by transport workers are studied to arrive at a useful method. An empirical model based on a detailed work study of individuals handling radioactive cargoes and the exposure rates at various distances from specific individual packages is developed. The personnel doses thus calculated compared reasonably well with the doses recorded on personnel monitoring badges. The personnel doses were also evaluated with reference to the total transport index handled by the workers, yielding results consistent with those reported elsewhere by earlier researchers. For assessing the collective dose to the public due to urban transport of radioactive material, the space around the vehicle transporting cargo was divided into a number of cells of dimensions 1mx1m. The radiation level in each cell was measured and the pedestrian density along the route was obtained. Using the pedestrian occupancy in the cells and the measured radiation levels, the total dose to the public was assessed. A similar assessment was made with respect to the passengers in the neighbouring vehicles. The suggested method of calculation may aid determination of the route and time of transport and the preferable traffic configuration for the vehicle carrying the radioactive consignments for optimizing the dose to the urban public

Occupational dose assessment in interventional cardiology in Serbia

International Nuclear Information System (INIS)

Kaljevic, J.; Ciraj-Bjelac, O.; Stankovic, J.; Arandjic, D.; Bozovic, P.; Antic, V.

2016-01-01

The objective of this work is to assess the occupational dose in interventional cardiology in a large hospital in Belgrade, Serbia. A double-dosimetry method was applied for the estimation of whole-body dose, using thermoluminescent dosemeters, calibrated in terms of the personal dose equivalent H p (10). Besides the double-dosimetry method, eye dose was also estimated by means of measuring ambient dose equivalent, H*(10), and doses per procedure were reported. Doses were assessed for 13 physicians, 6 nurses and 10 radiographers, for 2 consequent years. The maximum annual effective dose assessed was 4.3, 2.1 and 1.3 mSv for physicians, nurses and radiographers, respectively. The maximum doses recorded by the dosemeter worn at the collar level (over the apron) were 16.8, 11.9 and 4.5 mSv, respectively. This value was used for the eye lens dose assessment. Estimated doses are in accordance with or higher than annual dose limits for the occupational exposure. (authors)

Population dose commitments due to radioactive releases from nuclear-power-plant sites in 1978

International Nuclear Information System (INIS)

Peloquin, R.A.; Schwab, J.D.; Baker, D.A.

1982-06-01

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1978. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each site. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each site is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitment from both liquid and airborne pathways ranged from a high of 200 person-rem to a low of 0.0004 person-rem with an arithmetic mean of 14 person-rem. The total population dose for allsites was estimated at 660 person-rem for the 93 million people considered at risk. The average individual dose commitment from all pathways on a site basis ranged from a low of 3 x 10 -6 mrem to a high of 0.08 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites

Population dose commitments due to radioactive releases from Nuclear-Power-Plant Sites in 1979

International Nuclear Information System (INIS)

Baker, D.A.; Peloquin, R.A.

1982-12-01

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1979. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each site. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each site is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitment from both liquid and airborne pathways ranged from a high of 1300 person-rem to a low of 0.0002 person-rem with an arithmetic mean of 38 person-rem. The total population dose for all sites was estimated at 1800 person-rem for the 94 million people considered at risk. The average individual dose commitment from all pathways on a site basis ranged from a low of 2 x 10 - 6 mrem to a high of 0.7 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites

Ingestion of Nevada Test Site Fallout: Internal dose estimates

International Nuclear Information System (INIS)

Whicker, F.W.; Kirchner, T.B.; Anspaugh, L.R.

1996-01-01

This paper summarizes individual and collective dose estimates for the internal organs of hypothetical yet representative residents of selected communities that received measurable fallout from nuclear detonations at the Nevada Test Site. The doses, which resulted from ingestion of local and regional food products contaminated with over 20 radionuclides, were estimated with use of the PATHWAY food-chain-transport model to provide estimates of central tendency and uncertainty. The thyroid gland received much higher doses than other internal organs and tissues. In a avery few cases, infants might have received thyroid doses in excess of 1 Gy, depending on location, diet, and timing of fallout. 131 I was the primary thyroid dose contributor, and fresh milk was the main exposure pathway. With the exception of the thyroid, organ doses from the ingestion pathway were much smaller (<3%) than those from external gamma exposure to deposited fallout. Doses to residents living closest to the Nevada Test Site were contributed mainly by a few fallout events; doses to more distantly located people were generally smaller, but a greater number of events provided measurable contributions. The effectiveness of different fallout events in producing internal organ doses through ingestion varied dramatically with seasonal timing of the test, with maximum dose per unit fallout occurring for early summer depositions when milk cows were on pasture and fresh, local vegetables were used. Within specific communities, internal doses differed by age, sex, and lifestyle. Collective internal dose estimates for specific geographic areas are provided

PABLM, Doses from Radioactive Releases to Atmosphere and Food Chain

International Nuclear Information System (INIS)

Napier, B.A.; Kennedy, W.E. Jr.; Soldat, J.K.

1983-01-01

1 - Description of problem or function: PABLM calculates internal radiation doses to man from radionuclides in food products and external radiation doses from radionuclides in the environment. Radiation doses from radionuclides in the environment may be calculated from deposition on the soil or plants during an atmospheric or liquid release, or from exposure to residual radionuclides after the releases have ended. Radioactive decay is considered during the release, after deposition, and during holdup of food after harvest. The radiation dose models consider exposure to radionuclides deposited on the ground or crops from contaminated air or irrigation water, radionuclides in contaminated drinking water, aquatic foods raised in contaminated water, and radionuclides in bodies of water and sediments where people might fish, boat, or swim. For vegetation, the radiation dose model considers both direct deposition and uptake through roots. Doses may be calculated for either a maximum-exposed individual or for a population group. The program is designed to calculate accumulated radiation doses from the chronic ingestion of food products that contain radionuclides and doses from the external exposure to radionuclides in the environment. A first-year committed dose is calculated as well as an integrated dose for a selected number of years. 2 - Method of solution: A chain decay scheme including branching for transitions to and from isomeric states is used for radioactive decay. The equations for calculating internal radiation doses are derived from those given by the International Commission on Radio- logical Protection (ICRP) for body burdens and the maximum possible concentration (MPC) for each radionuclide. These doses are calculated as a function of radionuclide concentration in food products, ingestion rates, and a radionuclide-specific dose- commitment factor. Radiation doses from external exposure to contaminated water and soil are calculated using the basic assumption

Dose commitments due to radioactive releases from nuclear power plant sites: Methodology and data base. Supplement 1

Energy Technology Data Exchange (ETDEWEB)

Baker, D.A. [Pacific Northwest National Lab., Richland, WA (United States)

1996-06-01

This manual describes a dose assessment system used to estimate the population or collective dose commitments received via both airborne and waterborne pathways by persons living within a 2- to 80-kilometer region of a commercial operating power reactor for a specific year of effluent releases. Computer programs, data files, and utility routines are included which can be used in conjunction with an IBM or compatible personal computer to produce the required dose commitments and their statistical distributions. In addition, maximum individual airborne and waterborne dose commitments are estimated and compared to 10 CFR Part 50, Appendix 1, design objectives. This supplement is the last report in the NUREG/CR-2850 series.

Dose commitments due to radioactive releases from nuclear power plant sites: Methodology and data base. Supplement 1

International Nuclear Information System (INIS)

Baker, D.A.

1996-06-01

This manual describes a dose assessment system used to estimate the population or collective dose commitments received via both airborne and waterborne pathways by persons living within a 2- to 80-kilometer region of a commercial operating power reactor for a specific year of effluent releases. Computer programs, data files, and utility routines are included which can be used in conjunction with an IBM or compatible personal computer to produce the required dose commitments and their statistical distributions. In addition, maximum individual airborne and waterborne dose commitments are estimated and compared to 10 CFR Part 50, Appendix 1, design objectives. This supplement is the last report in the NUREG/CR-2850 series

Avoiding OHSS: Controlled Ovarian Low-Dose Stimulation in Women with PCOS.

Science.gov (United States)

Fischer, D; Reisenbüchler, C; Rösner, S; Haussmann, J; Wimberger, P; Goeckenjan, M

2016-06-01

The polycystic ovary syndrome is a common endocrine disorder which influences outcome and potential risks involved with controlled ovarian stimulation for artificial reproductive techniques (ART). Concrete practical recommendations for the dosage of gonadotropins, the preferred protocol and preventive methods to avoid ovarian hyperstimulation syndrome (OHSS) are lacking. We present retrospective data of 235 individually calculated gonadotropin low-dose stimulations for ART in a single center from 2012 to 2014. Clinical data and outcome parameter of patients diagnosed with PCOS according to Rotterdam criteria (n = 39) were compared with patients without PCOS (n = 196). The starting dose of gonadotropins was individually calculated depending on patients' age, BMI, ovarian reserve, ovarian response in previous cycles, and diagnostic criteria of PCOS. Mean age and duration of infertility did not differ between the groups, whereas mean BMI (p = 0.007) and AMH (p PCOS-group. A lower mean FSH-starting and maximum dose was administered to women with PCOS (p PCOS-patients did not differ from those of the control group (42.2 % and 34.4 % respectively). Neither mild, nor moderate or severe manifestation of OHSS occurred significantly more often in patients with PCOS. Our study supports the use of a calculated low-dose FSH-stimulation strategy in ART for patients with PCOS. Further randomized clinical trials should confirm this strategy and lead to define individual risk factors for OHSS, which can be used for recommendation of safer ART-techniques like in vitro maturation.

Estimation of individual radiation doses determined by the biological dosimetry method at the inhabitants of the Chernobyl region

International Nuclear Information System (INIS)

Nikolaevich, L.N.

1997-01-01

The results obtained by the method of the chromosome aberration analysis in human peripheral blood lymphocytes are given. Hematologically healthy inhabitants of Vetka and Khoiniki districts in Gomel Region (80 adults and 38 children), as well as persons suffering from hemoblastosis (acute lymphoblastic leukemia, acute myeloblastic leukemia) were examined. 27258 metaphase cells being analysed. Only two-hit aberrations (dicentric and ring chromosomes with fragments and without them), specific disturbances in response to radiation effect, were tested for estimating an individual dose of ionizing radiation. The examined groups of adults and children were formed depending on the value of an individual radiation dose: 0 kGy; from 0 to 1,4 kGy and from 1,5 to 3,0 kGy. 39% of adults took the dose up to 1,5 kGy and about 9% did above 2,0 kGy. The tendency towards increasing the amount of aberrant lymphocytes in peripheral blood is observed in persons who took the dose above 2,0 kGy. Among children 52,6% took the doses from 1,5 to 3,0 kGy. No increase in the level of aberrant cells in comparison with the children from the 'zero group' was observed in those children. Apparently, in some cases slightly reduced radiation doses can be obtained by the data of the chromosome analysis method since with the time elimination of a portion of these cells with unstable chromosome aberrations takes place. Elimination of chromosome aberrations in lymphocytes can be caused by different infectious processes which are accompanied by a pronounced immune response inducing inclusion of lymphocytes with aberrations in mitosis and , as a result, disappearance of unstable mutations. However, together with elimination of old chromosome aberrations new ones, caused by ongoing radiation, emerge in people living in radio contaminated regions and thus, the radiation dose determined by the chromosome analysis method even increases with years that can favour rise in malignant tumors. The radiation dose

Estimation of population doses from diagnostic medical examinations in Japan, 1974. III. Per caput mean marrow dose and leukemia significant dose

Energy Technology Data Exchange (ETDEWEB)

Hashizume, T; Maruyama, T; Kumamoto, Y [National Inst. of Radiological Sciences, Chiba (Japan)

1976-03-01

The mean per capita marrow dose and leukemia-significant dose from radiographic and fluoroscopic examinations in Japan have been estimated based on a 1974 nation wide survey of randomly sampled hospitals and clinics. To determine the mean marrow dose to an individual from a certain exposure of a given type of examination, the active marrow in the whole body was divided into 119 parts for an adult and 103 for a child. Dosimetric points on which the individual marrow doses were determined were set up in the center of each marrow part. The individual marrow doses at the dosimetric points in the beams of practical diagnostic x-rays were calculated on the basis of the exposure data on the patients selected in the nation wide survey, using depth dose curves experimentally determined for diagnostic x-rays. The mean individual marrow dose was averaged over the active marrow by summing, for each dosimetric point, the product of the fraction of active marrow exposed and the individual marrow dose at the dosimetric point. The leukemia significant dose was calculated by adopting a weighting factor that is, a leukemia significant factor. The factor was determined from the shape of the time-incidence curve for radiation-induced leukemia from the Hiroshima A-bomb and from the survival statistics for the average population. The resultant mean per capita marrow dose from radiographic and fluoroscopic examination was 37.0 and 70.0 mrad/person/year, respectively, with a total of 107.05 mrad/person/year. The leukemia significant dose was 32.1 mrad/person/year for radiographic examination and 61.2 mrad/person/year, with a total of 93.3. These values were compared with those of 1960 and 1969.

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Individual variations in dose response for spatial memory learning among outbred wistar rats exposed from 5 to 20 cGy of (56) Fe particles.

Science.gov (United States)

Wyrobek, Andrew J; Britten, Richard A

2016-06-01

Exposures of brain tissue to ionizing radiation can lead to persistent deficits in cognitive functions and behaviors. However, little is known about the quantitative relationships between exposure dose and neurological risks, especially for lower doses and among genetically diverse individuals. We investigated the dose relationship for spatial memory learning among genetically outbred male Wistar rats exposed to graded doses of (56) Fe particles (sham, 5, 10, 15, and 20 cGy; 1 GeV/n). Spatial memory learning was assessed on a Barnes maze using REL3 ratios measured at three months after exposure. Irradiated animals showed dose-dependent declines in spatial memory learning that were fit by a linear regression (P for slope learning at 10 cGy exposures, no detectable learning between 10 and 15 cGy, and worsened performances between 15 and 20 cGy. The proportions of poor learners and the magnitude of their impairment were fit by linear regressions with doubling doses of ∼10 cGy. In contrast, there were no detectable deficits in learning among the good learners in this dose range. Our findings suggest that genetically diverse individuals can vary substantially in their spatial memory learning, and that exposures at low doses appear to preferentially impact poor learners. This hypothesis invites future investigations of the genetic and physiological mechanisms of inter-individual variations in brain function related to spatial memory learning after low-dose HZE radiation exposures and to determine whether it also applies to physical trauma to brain tissue and exposures to chemical neurotoxicants. Environ. Mol. Mutagen. 57:331-340, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

42 CFR 409.62 - Lifetime maximum on inpatient psychiatric care.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Lifetime maximum on inpatient psychiatric care. 409....62 Lifetime maximum on inpatient psychiatric care. There is a lifetime maximum of 190 days on inpatient psychiatric hospital services available to any beneficiary. Therefore, once an individual receives...

Assessment of eye lens doses for workers during interventional radiology procedures

International Nuclear Information System (INIS)

Urboniene, A.; Sadzeviciene, E.; Ziliukas, J.

2015-01-01

The assessment of eye lens doses for workers during interventional radiology (IR) procedures was performed using a new eye lens dosemeter. In parallel, the results of routine individual monitoring were analysed and compared with the results obtained from measurements with a new eye lens dosemeter. The eye lens doses were assessed using H p (3) measured at the level of the eyes and were compared with H p (10) measured with the whole-body dosemeter above the lead collar. The information about use of protective measures, the number of performed interventional procedures per month and their fluoroscopy time was also collected. The assessment of doses to the lens of the eye was done for 50 IR workers at 9 Lithuanian hospitals for the period of 2012-2013. If the use of lead glasses is not taken into account, the estimated maximum annual dose equivalent to the lens of the eye was 82 mSv. (authors)

Insignificant levels of dose

International Nuclear Information System (INIS)

Webb, G.A.M.; McLean, A.S.

1977-01-01

The procedures recommended by the International Commission on Radiological Protection (ICRP) for making decisions concerning controllable sources of radiation exposure of the public include 'justification' and 'optimisation'. The tool recommended by the ICRP for reaching these decisions is collective dose or dose commitment supplemented by consideration of doses to individuals. In both these considerations the practical problem arises of whether very small doses to large numbers of people should contribute to the final decision-making process. It may be that at levels of dose which are small increments on natural background, the relationship between dose and effect is linear even though the slope may be close to zero. If so, collective dose is a meaningful concept and the calculation of total detriment for the purpose of justification could legitimately include all doses. In the calculation of collective doses for the purpose of optimisation, which involves decisions on how much money or resource should be allocated to dose reduction, it is necessary to appraise radiation detriment realistically. At low levels of dose to the individual such as those small by comparison with variations in natural background within the UK, the risk to the individual is such that his well-being will not be significantly changed by the presence or absence of the radiation dose. These small doses, which are well below the point at which an individual attaches significance, should not carry a societal significance. Societal acceptance of risk is analysed with a view to assessing a level of possible risk, and hence dose, below which resources should not in general be diverted to secure further reduction. A formulation for collective dose commitment is proposed incorporating a cut-off to exclude insignificant doses. The implications of this formulation in practical situations are discussed

Biosphere Modeling for the Dose Assessment of a HLW Repository: Development of ACBIO

Energy Technology Data Exchange (ETDEWEB)

Lee, Youn Myoung; Hwang, Yong Soo; Kang, Chul Hyung

2006-01-15

For the purpose of evaluating a dose rate to an individual due to a long-term release of nuclides from a HLW repository, a biosphere assessment model and an implemented code, ACBIO, based on the BIOMASS methodology have been developed by utilizing AMBER, a general compartment modeling tool. To demonstrate its practicability and usability as well as to observe the sensitivity of the compartment scheme, the concentration, the activity in the compartments as well as the annual flux between the compartments at their peak values, were calculated and investigated. For each case when changing the structure of the compartments and GBIs as well as varying selected input Kd values, all of which seem very important among the others, the dose rate per nuclide release rate is calculated separately and analyzed. From the maximum dose rates, the flux to dose conversion factors for each nuclide were derived, which are used for converting the nuclide release rate appearing from the geosphere through various GBIs to dose rates (Sv/y) for an individual in a critical group. It has also been observed that the compartment scheme, the identification of a possible exposure group and the GBIs could all be highly sensitive to the final consequences in a biosphere modeling.

Biosphere Modeling for the Dose Assessment of a HLW Repository: Development of ACBIO

International Nuclear Information System (INIS)

Lee, Youn Myoung; Hwang, Yong Soo; Kang, Chul Hyung

2006-01-01

For the purpose of evaluating a dose rate to an individual due to a long-term release of nuclides from a HLW repository, a biosphere assessment model and an implemented code, ACBIO, based on the BIOMASS methodology have been developed by utilizing AMBER, a general compartment modeling tool. To demonstrate its practicability and usability as well as to observe the sensitivity of the compartment scheme, the concentration, the activity in the compartments as well as the annual flux between the compartments at their peak values, were calculated and investigated. For each case when changing the structure of the compartments and GBIs as well as varying selected input Kd values, all of which seem very important among the others, the dose rate per nuclide release rate is calculated separately and analyzed. From the maximum dose rates, the flux to dose conversion factors for each nuclide were derived, which are used for converting the nuclide release rate appearing from the geosphere through various GBIs to dose rates (Sv/y) for an individual in a critical group. It has also been observed that the compartment scheme, the identification of a possible exposure group and the GBIs could all be highly sensitive to the final consequences in a biosphere modeling

Effects of Preceding Ethanol Intake on Glucose Response to Low-Dose Glucagon in Individuals With Type 1 Diabetes

DEFF Research Database (Denmark)

Ranjan, Ajenthen; Nørgaard, Kirsten; Tetzschner, Rikke

2018-01-01

OBJECTIVE: This study investigated whether preceding ethanol intake impairs glucose response to low-dose glucagon in individuals with type 1 diabetes. RESEARCH DESIGN AND METHODS: This was a randomized, crossover, placebo-controlled study in 12 insulin pump-treated individuals (median...... ethanol compared with placebo. The second glucagon bolus had similar responses between visits, but PG remained 1.8 ± 0.7 mmol/L lower after ethanol compared with placebo. CONCLUSIONS: The ability of low-dose glucagon to treat mild hypoglycemia persisted with preceding ethanol intake, although it tended...... to be metabolized, and a subcutaneous (s.c.) insulin bolus was given to induce mild hypoglycemia. When plasma glucose (PG) was ≤3.9 mmol/L, 100 µg glucagon was given s.c., followed by another s.c. 100 µg glucagon 2 h later. Primary end point was incremental peak PG induced by the first glucagon bolus. RESULTS...

From personnel dose to personal dose

International Nuclear Information System (INIS)

Hoefert, M.; Raffnsoe, R.C.; Tuyn, J.W.N.; Wittekind, D.

1985-01-01

From following the development of personnel doses at CERN over the past six years it has become evident that work in areas of induced radioactivity is the principal cause of exposure. The results of photon dose measurements free-in-air and around a phantom are presented and discussed in the light of new quantities in individual monitoring. The importance of these results, with respect to the practical situation, is discussed and the problem of phantom size is mentioned. Finally, the results of dose measurements in the phantom are presented, since such information is important in cases where it becomes necessary to transform personnel doses into personal doses. (author)

The usefulness of metal markers for CTV-based dose prescription in high-dose-rate interstitial brachytherapy

International Nuclear Information System (INIS)

Yoshida, Ken; Mitomo, Masanori; Nose, Takayuki; Koizumi, Masahiko; Nishiyama, Kinji; Yoshida, Mineo

2002-01-01

We employ a clinical target volume (CTV)-based dose prescription for high-dose-rate (HDR) interstitial brachytherapy. However, it is not easy to define CTV and organs at risk (OAR) from X-ray film or CT scanning. To solve this problem, we have utilized metal markers since October 1999. Moreover, metal markers can help modify dose prescription. By regulating the doses to the metal markers, refining the dose prescription can easily be achieved. In this research, we investigated the usefulness of the metal markers. Between October 1999 and May 2001, 51 patients were implanted with metal markers at Osaka Medical Center for Cancer and Cardiovascular Diseases (OMCC), Osaka National Hospital (ONH) and Sanda City Hospital (SCH). Forty-nine patients (head and neck: 32; pelvis: 11; soft tissue: 3; breast: 3) using metal markers were analyzed. During operation, we implanted 179 metal markers (49 patients) to CTV and 151 markers (26 patients) to OAR. At treatment planning, CTV was reconstructed judging from the metal markers, applicator position and operation records. Generally, we prescribed the tumoricidal dose to an isodose surface that covers CTV. We also planned to limit the doses to OAR lower than certain levels. The maximum normal tissue doses were decided 80%, 150%, 100%, 50% and 200% of the prescribed doses for the rectum, the urethra, the mandible, the skin and the large vessel, respectively. The doses to the metal markers using CTV-based dose prescription were generated. These were compared with the doses theoretically calculated with the Paris system. Treatment results were also investigated. The doses to the 158 metal markers (42 patients) for CTV were higher than ''tumoricidal dose''. In 7 patients, as a result of compromised dose prescription, 9 markers were lower than the tumoricidal dose. The other 12 markers (7%) were excluded from dose evaluation because they were judged as miss-implanted. The doses to the 142 metal markers (24 patients) for OAR were lower

Benefit-harm analysis and charts for individualized and preference-sensitive prevention: example of low dose aspirin for primary prevention of cardiovascular disease and cancer.

Science.gov (United States)

Puhan, Milo A; Yu, Tsung; Stegeman, Inge; Varadhan, Ravi; Singh, Sonal; Boyd, Cynthia M

2015-10-01

Clinical practice guidelines provide separate recommendations for different diseases that may be prevented or treated by the same intervention. Also, they commonly provide recommendations for entire populations but not for individuals. To address these two limitations, our aim was to conduct benefit-harm analyses for a wide range of individuals using the example of low dose aspirin for primary prevention of cardiovascular disease and cancer and to develop Benefit-Harm Charts that show the overall benefit-harm balance for individuals. We used quantitative benefit-harm modeling that included 16 outcomes to estimate the probability that low dose aspirin provides more benefits than harms for a wide range of men and women between 45 and 84 years of age and without a previous myocardial infarction, severe ischemic stroke, or cancer. We repeated the quantitative benefit-harm modeling for different combinations of age, sex, and outcome risks for severe ischemic and hemorrhagic stroke, myocardial infarction, cancers, and severe gastrointestinal bleeds. The analyses considered weights for the outcomes, statistical uncertainty of the effects of aspirin, and death as a competing risk. We constructed Benefit-Harm Charts that show the benefit-harm balance for different combinations of outcome risks. The Benefit-Harm Charts ( http://www.benefit-harm-balance.com ) we have created show that the benefit-harm balance differs largely across a primary prevention population. Low dose aspirin is likely to provide more benefits than harms in men, elderly people, and in those at low risk for severe gastrointestinal bleeds. Individual preferences have a major impact on the benefit-harm balance. If, for example, it is a high priority for individuals to prevent stroke and severe cancers while severe gastrointestinal bleeds are deemed to be of little importance, the benefit-harm balance is likely to favor low dose aspirin for most individuals. Instead, if severe gastrointestinal bleeds are

Protocol for adaptation of internal dosimetry techniques for planning of individualized doses of 131I in pediatric patients

International Nuclear Information System (INIS)

Biancardi, Rodrigo

2011-01-01

The optimization of radiation doses is emphasized in diseases with good prognosis, as differentiated thyroid carcinomas, especially in pediatric patients, since the radiation risk is conversely proportional to age. Aiming to establish individual treatment planning, it has been studied four dosimetry methodologies (external dose monitoring, image quantification, urine and blood bioassay) for four 13.3 ± 1.5-year-old female patients, who received 107 ± 15 MBq (2,9 ± 0,4 mCi) for tracer dose and 5.5 ± 0.3 GBq (149 ± 8 mCi) for thyroid ablation. Effective half-lives, residence times and cumulated activities were estimated in organs and tissues with iodine uptake, through planar images quantification by conjugate-view and attenuation correction, in order to compare biokinetic behavior in tracer dose and ablative dose phases. For external monitoring, two patients had similar whole-body effective half-lives in both phases. For this methodology, despite the uncertainties associated to measurements, equipment used and procedures performed were adequate. For urine bioassay, there were not similarities among the patients whole-body effective half-lives. Through blood bioassay, it was observed that 0.2 % of the administered activity for ablative dose remained in the blood until 76 hours after administration. The external monitoring allowed estimating effective doses in patients mothers by conversion of the environmental equivalent dose. In the ablative dose phase, the effective doses resulted in 1.3 ± 0.3 mSv in the hospital and 0.3 ± 0.1 mSv in patients houses. (author)

Fast skin dose estimation system for interventional radiology.

Science.gov (United States)

Takata, Takeshi; Kotoku, Jun'ichi; Maejima, Hideyuki; Kumagai, Shinobu; Arai, Norikazu; Kobayashi, Takenori; Shiraishi, Kenshiro; Yamamoto, Masayoshi; Kondo, Hiroshi; Furui, Shigeru

2018-03-01

To minimise the radiation dermatitis related to interventional radiology (IR), rapid and accurate dose estimation has been sought for all procedures. We propose a technique for estimating the patient skin dose rapidly and accurately using Monte Carlo (MC) simulation with a graphical processing unit (GPU, GTX 1080; Nvidia Corp.). The skin dose distribution is simulated based on an individual patient's computed tomography (CT) dataset for fluoroscopic conditions after the CT dataset has been segmented into air, water and bone based on pixel values. The skin is assumed to be one layer at the outer surface of the body. Fluoroscopic conditions are obtained from a log file of a fluoroscopic examination. Estimating the absorbed skin dose distribution requires calibration of the dose simulated by our system. For this purpose, a linear function was used to approximate the relation between the simulated dose and the measured dose using radiophotoluminescence (RPL) glass dosimeters in a water-equivalent phantom. Differences of maximum skin dose between our system and the Particle and Heavy Ion Transport code System (PHITS) were as high as 6.1%. The relative statistical error (2 σ) for the simulated dose obtained using our system was ≤3.5%. Using a GPU, the simulation on the chest CT dataset aiming at the heart was within 3.49 s on average: the GPU is 122 times faster than a CPU (Core i7-7700K; Intel Corp.). Our system (using the GPU, the log file, and the CT dataset) estimated the skin dose more rapidly and more accurately than conventional methods.

Occupational dose constraint

International Nuclear Information System (INIS)

Heilbron Filho, Paulo Fernando Lavalle; Xavier, Ana Maria

2005-01-01

The revision process of the international radiological protection regulations has resulted in the adoption of new concepts, such as practice, intervention, avoidable and restriction of dose (dose constraint). The latter deserving of special mention since it may involve reducing a priori of the dose limits established both for the public and to individuals occupationally exposed, values that can be further reduced, depending on the application of the principle of optimization. This article aims to present, with clarity, from the criteria adopted to define dose constraint values to the public, a methodology to establish the dose constraint values for occupationally exposed individuals, as well as an example of the application of this methodology to the practice of industrial radiography

INTERCOMPARISON ON THE MEASUREMENT OF THE QUANTITY PERSONAL DOSE EQUIVALENT HP(10) IN PHOTON FIELDS. LINEARITY DEPENDENCE, LOWER LIMIT OF DETECTION AND UNCERTAINTY IN MEASUREMENT OF DOSIMETRY SYSTEMS OF INDIVIDUAL MONITORING SERVICES IN GABON AND GHANA.

Science.gov (United States)

Ondo Meye, P; Schandorf, C; Amoako, J K; Manteaw, P O; Amoatey, E A; Adjei, D N

2017-12-01

An inter-comparison study was conducted to assess the capability of dosimetry systems of individual monitoring services (IMSs) in Gabon and Ghana to measure personal dose equivalent Hp(10) in photon fields. The performance indicators assessed were the lower limit of detection, linearity and uncertainty in measurement. Monthly and quarterly recording levels were proposed with corresponding values of 0.08 and 0.025 mSv, and 0.05 and 0.15 mSv for the TLD and OSL systems, respectively. The linearity dependence of the dosimetry systems was performed following the requirement given in the Standard IEC 62387 of the International Electrotechnical Commission (IEC). The results obtained for the two systems were satisfactory. The procedure followed for the uncertainty assessment is the one given in the IEC technical report TR62461. The maximum relative overall uncertainties, in absolute value, expressed in terms of Hp(10), for the TL dosimetry system Harshaw 6600, are 44. 35% for true doses below 0.40 mSv and 36.33% for true doses ≥0.40 mSv. For the OSL dosimetry system microStar, the maximum relative overall uncertainties, in absolute value, are 52.17% for true doses below 0.40 mSv and 37.43% for true doses ≥0.40 mSv. These results are in good agreement with the requirements for accuracy of the International Commission on Radiological protection. When expressing the uncertainties in terms of response, comparison with the IAEA requirements for overall accuracy showed that the uncertainty results were also acceptable. The values of Hp(10) directly measured by the two dosimetry systems showed a significant underestimation for the Harshaw 6600 system, and a slight overestimation for the microStar system. After correction for linearity of the measured doses, the two dosimetry systems gave better and comparable results. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

ARRRG/FOOD, Doses from Radioactive Release to Food Chain

International Nuclear Information System (INIS)

Napier, B.A.; Roswell, R.L.; Kennedy, W.E. Jr.; Strenge, D.L.

1984-01-01

1 - Description of problem or function: ARRRG calculates radiation doses to humans for radionuclides released to bodies of water from which people might obtain fish, other aquatic foods, or drinking water, and in which they might fish, swim, or boat. FOOD calculates radiation doses to humans from deposition on farm or garden soil and crops during either an atmospheric or water release of radionuclides. Deposition may be either directly from the air or from irrigation water. With both programs, doses may be calculated for either a maximum- exposed individual or for a population group. Doses calculated are a one-year dose and a committed dose from one year of exposure. The exposure is usually considered as chronic; however, equations are included to calculate dose and dose commitment from acute, one-time, exposure. 2 - Method of solution: The radiation doses from external exposure to contaminated farm fields or shorelines are calculated assuming an 'infinite' flat plane source of radionuclides. A factor of two is included for surface roughness, and a modifying factor is used to compensate for finite extent in the shoreline calculations. The radionuclide concentrations in aquatic and irrigated food products are based on the radionuclide concentration in the contaminated water, which is based on the release rate of radioactive contamination and the characteristics of the receiving water body. Concentration of radionuclides in plants depends on the concentrations in the soil, air, and water. Concentration of radionuclides in farm animal products, such as milk, meat, or eggs, depends on the animal's consumption of feed, forage, and water containing radionuclides. For persons swimming in contaminated water, the dose is calculated assuming that the body of water is an infinite medium relative to the range of emitted radiations. Persons boating on the water are assumed to be exposed to a dose rate half that of swimmers. Internal doses are calculated as a function of

Radiation-induced rib fracture after stereotactic body radiotherapy with a total dose of 54–56 Gy given in 9–7 fractions for patients with peripheral lung tumor: impact of maximum dose and fraction size

International Nuclear Information System (INIS)

Aoki, Masahiko; Sato, Mariko; Hirose, Katsumi; Akimoto, Hiroyoshi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Ono, Shuichi; Takai, Yoshihiro

2015-01-01

Radiation-induced rib fracture after stereotactic body radiotherapy (SBRT) for lung cancer has been recently reported. However, incidence of radiation-induced rib fracture after SBRT using moderate fraction sizes with a long-term follow-up time are not clarified. We examined incidence and risk factors of radiation-induced rib fracture after SBRT using moderate fraction sizes for the patients with peripherally located lung tumor. During 2003–2008, 41 patients with 42 lung tumors were treated with SBRT to 54–56 Gy in 9–7 fractions. The endpoint in the study was radiation-induced rib fracture detected by CT scan after the treatment. All ribs where the irradiated doses were more than 80% of prescribed dose were selected and contoured to build the dose-volume histograms (DVHs). Comparisons of the several factors obtained from the DVHs and the probabilities of rib fracture calculated by Kaplan-Meier method were performed in the study. Median follow-up time was 68 months. Among 75 contoured ribs, 23 rib fractures were observed in 34% of the patients during 16–48 months after SBRT, however, no patients complained of chest wall pain. The 4-year probabilities of rib fracture for maximum dose of ribs (Dmax) more than and less than 54 Gy were 47.7% and 12.9% (p = 0.0184), and for fraction size of 6, 7 and 8 Gy were 19.5%, 31.2% and 55.7% (p = 0.0458), respectively. Other factors, such as D2cc, mean dose of ribs, V10–55, age, sex, and planning target volume were not significantly different. The doses and fractionations used in this study resulted in no clinically significant rib fractures for this population, but that higher Dmax and dose per fraction treatments resulted in an increase in asymptomatic grade 1 rib fractures

Radiation doses to normal tissues during craniospinal irradiation ...

African Journals Online (AJOL)

Mohamed Farouk Mostafa

2011-10-15

Oct 15, 2011 ... not in the center of the brain as this shows lower doses to eyes and lenses. ª 2011 Alexandria .... dose plan function was used to check the dose coverage of the .... maximum dose received by the right and left lens were listed.

Population dose commitments due to radioactive releases from nuclear power plant sites in 1986

International Nuclear Information System (INIS)

Baker, D.A.

1989-10-01

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1986. Fifty-year dose commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 66 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 31 person-rem to a low of 0.0007 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 1.7 person-rem. The total population dose for all sites was estimated at 110 person-rem for the 140 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 2 x 10 -6 mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. 12 refs

Population dose commitments due to radioactive releases from nuclear power plant sites in 1984

International Nuclear Information System (INIS)

Baker, D.A.

1988-01-01

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1984. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 56 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 110 person-rem to a low of 0.002 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 5 person-rem. The total population dose for all sites was estimated at 280 person-rem for the 100 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 6 x 10 -6 mrem to a high of 0.04 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites

Population dose commitments due to radioactive releases from nuclear power plant sites in 1985

International Nuclear Information System (INIS)

Baker, D.A.

1988-08-01

Population radiation dose commitments have been estimated from reported radionuclide releases from commericial power reactors operating during 1985. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 61 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 73 person-rem to a low of 0.011 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 3 person-rem. The total population dose for all sites was estimated at 200 person-rem for the 110 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 5 /times/ 10/sup /minus/6/ mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites

Evaluation of personal dose equivalent 'HP(d)' in a external individual monitoring system for X and gamma radiation

International Nuclear Information System (INIS)

Santoro, C.; Antonio Filho, J.; Santos, M.A.P.

2007-01-01

The good of individual monitoring for external radiation is the assessment of occupational exposure from X and γ radiations in order to assure that the radiological conditions of the workplace are acceptable, safe and satisfactory. The evaluation of radiations doses for workers must not exceed dose limits specified for workers, according to national regulatory agencies. Nowadays, there are two external monitoring systems in use, both based on ICRU definitions. In the conventional system, the workers doses are evaluated in terms of Hx. The personal dosimeter is worn over chest surface and it is calibrated in function of air kerma. In the new system, the workers doses are evaluated in terms of HP(d) and the personal dosimeter is calibrated in function of phantom doses. The aim of this paper is to adapt an external dosimetry laboratory (based on photographic dosimetry) to evaluate the personal dosimeters in terms of HP(d). In this way, a simple methodology, based on linear programming, was utilized. In this adaptation, calibration curves were obtained for radiation qualities (W and N series) described by International Organization for Standardization (ISO 4037-1, 1995). These calibration curves offer a better accuracy on dose determinations and energy below 140 keV, improving the quality of service rendered the society. (author)

Factors affecting radiation doses from dedicated rail transport of spent reactor fuel

International Nuclear Information System (INIS)

Martin, J.E.

1988-01-01

This paper reports there are two exposure control concerns associated with the shipment of spent reactor fuel in dedicated trains -- compliance with transportation regulations for maximum allowable radiation levels, and minimizing the dose received by the general public. This article examines the methods used to calculate the dose equivalent rates alongside stationary (transport regulations) and moving trains (public exposure) of various lengths. The factors examined include the source term, the effect of overlapping radiation fields, the speed of the train, and the location of the population relative to the train. Trains made up of series of cars that individually meet transport regulations can, as a whole, exceed transport vehicle dose equivalent rate limits by up to 23% due to overlapping radiation fields. For moving trains and the worst case analyzed -- a person located 20 feet from the tracks and a train speed of 5 mph --- 141 rail cars would have to pass by to deliver a dose equivalent of 1 mrem

Motion-induced dose artifacts in helical tomotherapy

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Kim, Bryan; Chen, Jeff; Battista, Jerry [London Regional Cancer Program, London Health Sciences Centre, London, ON (Canada); Kron, Tomas [Peter MacCallum Cancer Center, Melbourne (Australia)], E-mail: bryan.kim@lhsc.on.ca

2009-10-07

Tumor motion is a particular concern for a complex treatment modality such as helical tomotherapy, where couch position, gantry rotation and MLC leaf opening all change with time. In the present study, we have investigated the impact of tumor motion for helical tomotherapy, which could result in three distinct motion-induced dose artifacts, namely (1) dose rounding, (2) dose rippling and (3) IMRT leaf opening asynchronization effect. Dose rounding and dose rippling effects have been previously described, while the IMRT leaf opening asynchronization effect is a newly discovered motion-induced dose artifact. Dose rounding is the penumbral widening of a delivered dose distribution near the edges of a target volume along the direction of tumor motion. Dose rippling is a series of periodic dose peaks and valleys observed within the target region along the direction of couch motion, due to an asynchronous interplay between the couch motion and the longitudinal component of tumor motion. The IMRT leaf opening asynchronization effect is caused by an asynchronous interplay between the temporal patterns of leaf openings and tumor motion. The characteristics of each dose artifact were investigated individually as functions of target motion amplitude and period for both non-IMRT and IMRT helical tomotherapy cases, through computer simulation modeling and experimental verification. The longitudinal dose profiles generated by the simulation program agreed with the experimental data within {+-}0.5% and {+-}1.5% inside the PTV region for the non-IMRT and IMRT cases, respectively. The dose rounding effect produced a penumbral increase up to 20.5 mm for peak-to-peak target motion amplitudes ranging from 1.0 cm to 5.0 cm. Maximum dose rippling magnitude of 25% was calculated, when the target motion period approached an unusually high value of 10 s. The IMRT leaf opening asynchronization effect produced dose differences ranging from -29% to 7% inside the PTV region. This information

Impact of geometric uncertainties on dose calculations for intensity modulated radiation therapy of prostate cancer

Science.gov (United States)

Jiang, Runqing

uniform dose per fraction (EUDf) and NTCP. The dose distribution including geometric uncertainties was determined from integration of the convolution of the static dose gradient with the PDF. Integration of the convolution of the static dose and derivative of the PDF can also be used to determine the dose including geometric uncertainties although this method was not investigated in detail. Local maximum dose gradient (LMDG) was determined via optimization of dose objective function by manually adjusting DVH control points or selecting beam numbers and directions during IMRT treatment planning. Minimum SD (SDmin) is used when geometric uncertainty is corrected with verification imaging. Maximum SD (SDmax) is used when the geometric uncertainty is known to be large and difficult to manage. SDmax was 4.38 mm in anterior-posterior (AP) direction, 2.70 mm in left-right (LR) direction and 4.35 mm in superior-inferior (SI) direction; SDmin was 1.1 mm in all three directions if less than 2 mm threshold was used for uncorrected fractions in every direction. EUDf is a useful QA parameter for interpreting the biological impact of geometric uncertainties on the static dose distribution. The EUD f has been used as the basis for the time-course NTCP evaluation in the thesis. Relative NTCP values are useful for comparative QA checking by normalizing known complications (e.g. reported in the RTOG studies) to specific DVH control points. For prostate cancer patients, rectal complications were evaluated from specific RTOG clinical trials and detailed evaluation of the treatment techniques (e.g. dose prescription, DVH, number of beams, bean angles). Treatment plans that did not meet DVH constraints represented additional complication risk. Geometric uncertainties improved or worsened rectal NTCP depending on individual internal organ motion within patient.

Modification of beta dose evaluation algorithm for better accuracy in personnel monitoring

International Nuclear Information System (INIS)

Rakesh, R.B.; Kumar, Munish; Sneha, C.; Ratna, P.; Datta, D.

2016-01-01

Dose due to beta radiations is the main contributor to the skin dose. Assessment of individual dose (whole body, skin, extremity) in India is based on CaSO 4 :Dy based Teflon embedded TLD badge used for personnel monitoring. The design of the dosemeter enables identification of radiation type which, in turn, allows use of radiation specific algorithm for dose evaluation. The difference of response of three discs of the TLD badge to beta radiation in beta/beta-gamma fields is due to the presence of different filters corresponding to the three discs. The response of disc under metal filter (D 1 ) to beta being negligible while that of open disc (D 3 ) is the maximum. The ratio of response of open disc to that under Perspex (D 3 /D 2 ) to beta is highly dependent on its energy and angle of incidence. Therefore estimation of dose due to beta is based on response of open disc corrected for the energy of beta using D 3 /D 2

Editorial: New operational dose equivalent quantities

International Nuclear Information System (INIS)

Harvey, J.R.

1985-01-01

The ICRU Report 39 entitled ''Determination of Dose Equivalents Resulting from External Radiation Sources'' is briefly discussed. Four new operational dose equivalent quantities have been recommended in ICRU 39. The 'ambient dose equivalent' and the 'directional dose equivalent' are applicable to environmental monitoring and the 'individual dose equivalent, penetrating' and the 'individual dose equivalent, superficial' are applicable to individual monitoring. The quantities should meet the needs of day-to-day operational practice, while being acceptable to those concerned with metrological precision, and at the same time be used to give effective control consistent with current perceptions of the risks associated with exposure to ionizing radiations. (U.K.)

ON THE ADVISABILITY OF REJECTION OF SUBTRACTION OF BACKGROUND DOSIMETERS INDICATION VALUES FROM THE MEASURED VALUES OF INDIVIDUAL DOSES OF OCCUPATIONAL EXPOSURE OF A-GROUP PERSONNEL

Directory of Open Access Journals (Sweden)

A. N. Barkovskiy

2013-01-01

Full Text Available An article contains substantiation of advisability of rejection of subtraction of background dosimeters indication values from the measured values of individual doses of occupational exposure of A-group personnel in the process of carrying out of individual dosimetry control of medical organizations stuff which was implemented in the Methodical Guideline 2.6.1.3015-12. It is shown that mentioned procedure is firstly incorrect when we deal with low doses, when the impact of natural exposure could be really considerable and secondary senseless when we deal with dose values close to the dose limit value for A-group personnel when the impact of natural exposure is much lower then the error of measurements. It is suggested to carry out the account of the impact of natural exposure into personnel average doses basing on the analysis of statistical distributions of personnel individual doses and on indications of background dosimeters. It is suggested to add the information about indications of background dosimeters into the Base of Federal Statistical Supervision № 1-DOS as it is prescribed in the Methodical Guideline 2.6.1.3015-12. This article is the respond to the article of A.I. Grigoriev published in the present issue of Journal, in which the author contests the reasonableness of this provision.

Cocoa consumption dose-dependently improves flow-mediated dilation and arterial stiffness decreasing blood pressure in healthy individuals.

Science.gov (United States)

Grassi, Davide; Desideri, Giovambattista; Necozione, Stefano; di Giosia, Paolo; Barnabei, Remo; Allegaert, Leen; Bernaert, Herwig; Ferri, Claudio

2015-02-01

Cocoa flavonoids exert beneficial vascular effects and reduce the risk of cardiovascular morbidity and mortality. Nevertheless, the involved mechanisms have not been clarified and no study has yet focused on the dose-response effects. We aimed to investigate the effects of different doses of cocoa flavonoids on flow-mediated dilation (FMD), endothelin-1 (ET-1), pulse wave velocity (PWV), and SBP and DBP. According to a randomized, double-blind, controlled, cross-over design, 20 healthy volunteers (1.5% improvement in FMD in 20 individuals: 0.99 at alpha = 0.05) were assigned to receive either five treatments with daily intake of 10 g cocoa (0, 80, 200, 500 and 800 mg cocoa flavonoids/day) in five periods lasting 1 week each. Cocoa dose-dependently increased FMD from 6.2% (control) to 7.3, 7.6, 8.1 and 8.2% after the different flavonoid doses, respectively (P cocoa flavonoids per day increased FMD (P Cocoa dose-dependently decreased PWV (P Cocoa intake decreased office blood pressure (BP) (SBP: -4.8 ± 1.03  mmHg, P cocoa ingestion decreased 24-h (P = 0.05) and daytime (P = 0.038) SBP, and 24-h (P = 0.0064), daytime (P = 0.0088) and night-time (P = 0.0352) pulse pressure. Compared with the control, cocoa dose-dependently decreased ET-1 levels [from 17.1 (control) to 15.2, 14.5, 14.2 and 14.1 pg/ml, after the different flavonoid doses, respectively (P for treatment cocoa dose-dependently improved FMD and decreased PWV and ET-1 also by ameliorating office and monitored BP. Our findings are clinically relevant, suggesting cocoa, with very low calorie intake, might be reasonably incorporated into a dietary approach, representing a consistent tool in cardiovascular prevention.

Influence of intravenous opioid dose on postoperative ileus.

Science.gov (United States)

Barletta, Jeffrey F; Asgeirsson, Theodor; Senagore, Anthony J

2011-07-01

Intravenous opioids represent a major component in the pathophysiology of postoperative ileus (POI). However, the most appropriate measure and threshold to quantify the association between opioid dose (eg, average daily, cumulative, maximum daily) and POI remains unknown. To evaluate the relationship between opioid dose, POI, and length of stay (LOS) and identify the opioid measure that was most strongly associated with POI. Consecutive patients admitted to a community teaching hospital who underwent elective colorectal surgery by any technique with an enhanced-recovery protocol postoperatively were retrospectively identified. Patients were excluded if they received epidural analgesia, developed a major intraabdominal complication or medical complication, or had a prolonged workup prior to surgery. Intravenous opioid doses were quantified and converted to hydromorphone equivalents. Classification and regression tree (CART) analysis was used to determine the dosing threshold for the opioid measure most associated with POI and define high versus low use of opioids. Risk factors for POI and prolonged LOS were determined through multivariate analysis. The incidence of POI in 279 patients was 8.6%. CART analysis identified a maximum daily intravenous hydromorphone dose of 2 mg or more as the opioid measure most associated with POI. Multivariate analysis revealed maximum daily hydromorphone dose of 2 mg or more (p = 0.034), open surgical technique (p = 0.045), and days of intravenous narcotic therapy (p = 0.003) as significant risk factors for POI. Variables associated with increased LOS were POI (p POI and prolonged LOS, particularly when the maximum hydromorphone dose per day exceeds 2 mg. Clinicians should consider alternative, nonopioid-based pain management options when this occurs.

Controllable dose

International Nuclear Information System (INIS)

Alvarez R, J.T.; Anaya M, R.A.

2004-01-01

With the purpose of eliminating the controversy about the lineal hypothesis without threshold which found the systems of dose limitation of the recommendations of ICRP 26 and 60, at the end of last decade R. Clarke president of the ICRP proposed the concept of Controllable Dose: as the dose or dose sum that an individual receives from a particular source which can be reasonably controllable by means of any means; said concept proposes a change in the philosophy of the radiological protection of its concern by social approaches to an individual focus. In this work a panorama of the foundations is presented, convenient and inconveniences that this proposal has loosened in the international community of the radiological protection, with the purpose of to familiarize to our Mexican community in radiological protection with these new concepts. (Author)

Comparative study of eye dose and chest dose received during radiopharmaceutical production processes

International Nuclear Information System (INIS)

Chindarkar, A.S.; Chavan, S.V.; Sawant, D.K.; Sahoo, L.; Gopalakrishnan, R.K.; Sneha, C.; Sachdev, S.S.; Dey, A.C.

2018-01-01

Radiopharmaceutical laboratory, BRIT, Vashi produces different radiopharmaceuticals of 131 I, 153 Sm, 99 Mo/ 99m Tc and 177 Lu. Principle gamma energies of these isotopes vary from 103 to 740 KeV and their maximum beta energies vary from 384 to 1214 KeV. In the light of the revised eye lens dose limit recommended in IAEA Basic Safety Standard Interim Edition No. GSR Part 3 (IAEA-2011), the study of radiation dose for eye lens was carried out using CaSO 4 : Dy based Thermo luminescence dosimeter (TLD). This TLD was worn at center of the forehead to measure eye lens dose. This TLD dose was then compared with chest TLD dose to deduce any correlation between these TLD doses. These TLD doses were assessed on quarterly basis. Eight quarter data of these TLD doses were compared

Implication of new CEC recommendations for individual monitoring for external radiation doses to the skin and the extremities

DEFF Research Database (Denmark)

Christensen, P.; Julius, H.W.; Marshall, T.O.

1991-01-01

A drafting group consisting of the above authors has assisted the CEC in revising the CEC document Technical Recommendations for Monitoring the Exposure to Individuals to External Radiation, EUR 5287, published in 1975. The paper highlights sections of the revised version relating particularly...... to irradiation of the skin and the extremities and focusses on problems connected to exposure to weakly penetrating radiations. Concepts of individual monitoring for external radiation exposures to the skin of the whole body and to the extremities are discussed and guidance is given as regards dose quantities...

SU-G-201-14: Is Maximum Skin Dose a Reliable Metric for Accelerated Partial Breast Irradiation with Brachytherapy?

International Nuclear Information System (INIS)

Park, S; Ragab, O; Patel, S; Demanes, J; Kamrava, M; Kim, Y

2016-01-01

Purpose: To evaluate the reliability of the maximum point dose (Dmax) to the skin surface as a dosimetric constraint, we investigated the correlation between Dmax at the skin surface and dose metrics at various definitions of skin thickness. Methods: 42 patients treated with APBI using a Strut Adjusted Volume Implant (SAVI) applicator between 2010 and 2014 were retrospectively reviewed. Target (PTV-EVAL) and organs at risk (OARs: skin, lung, and ribs) were delineated on a CT following NSABP B-39 guidelines. Six skin structures were contoured: a rind 3cm external to the body surface and 1, 2, 3, 4, and 5mm thick rinds deep to the body surface. Inverse planning simulated annealing optimization was used to deliver 32–34Gy in 8-10 fractions to the target while minimizing OAR doses. Dmax, D0.1cc, D1.0cc, and D2.0cc to the various skin structures were calculated. Linear regressions between the metrics were evaluated using the coefficient of determination (R"2). Results: The average±SD PTV-EVAL volume and cavity-to-skin distances were 71.1±28.5cc and 6.9±5.0mm. The target V90 and V95 were 97.3±2.3% and 95.1±3.2%. The Dmax to the skin structures were 78.7±10.2% (skin surface), 82.2±10.7% (skin-1mm), 89.4±12.6% (skin-2mm), 97.9±15.4% (skin-3mm), 114.1±32.5% (skin-4mm), and 157.0±85.3% (skin-5mm). Linear regression analysis showed D1.0cc and D2.0cc to the skin 1mm and Dmax to the skin-4mm and 5mm were poorly correlated with other metrics (R"2=0.413±0.204). Dmax to the skin surface was well correlated (R"2=0.910±0.047) and D1.0cc to the skin-3mm was strongly correlated with all subsurface skin layers (R"2=0.935±0.050). Conclusion: Dmax to the skin surface is a relevant metric for breast skin dose. Contouring discontinuities in the skin with a 1mm subsurface rind and the active dwells in the skin 4 and 5mm introduced significant variations in skin DVH. D0.1cc, D1.0cc, and D2.0cc to a 3mm skin rind are more robust metrics in breast brachytherapy.

The biological response of plucked human hair to low-dose radiation: a measure of individual radiosensitivity and a technique for biological dosimetry

International Nuclear Information System (INIS)

Swain, D.

1997-01-01

It is often assumed that the effects of radiation are linear with dose and that high dose effects can be extrapolated to low dose levels. However, there are a variety of mechanisms which can alter the response at low doses. The most important of these relate to induced sensitivity or induced repair mechanisms. It is therefore important that this area is studied in more depth by looking at the molecular effects and damage to cells at low doses. It is well known that there are certain rare genetic syndromes which predispose individuals to cancer, e.g. ataxia telangiectasia. It is also probable that there is a large range of sensitivity in the natural variation of individuals to the risk of radiation-induced cancer. It is proposed that radiosensitivity is studied using stimulated lymphocytes from whole blood and the technique extended to look at the effects in cell cultures established from human hair. Radiation treatment of cell cultures established from plucked human hair has been previously advocated as a non-invasive technique for non-uniform biological dosimetry and it is proposed that these techniques are adapted to the use of hair to estimate individual radiosensitivity. The aim is to establish and optimize these techniques for culturing keratinocytes from plucked human hair follicles with a view to study biological markers for the subsequent assessment of radiosensitivity. Preliminary results are promising and suggest that the technique for culturing keratinocytes from hair presents a feasible approach. Results from this primary cell culture technique and results from the comparison of the micronuclei data obtained from the cell cultures and stimulated lymphocytes will be presented. (author)

CLINICAL AND PHARMACOLOGICAL APPROACHES TO OPTIMIZE THE DOSING REGIMEN OF ANTIBACTERIAL DRUGS IN PEDIATRICS

Directory of Open Access Journals (Sweden)

Natal’ya B. Lazareva

2018-01-01

Full Text Available The rational use of antibacterial drugs in children implies an adequate choice of the necessary medication, its dosing regimen, and the duration of treatment in order to achieve maximum efficacy and minimize toxic effects. The knowledge of pharmacokinetic and pharmacodynamic profiles of the antibacterial drug plays a crucial role for optimizing the dosing regimen. The strategy of individual choice of the dosing regimen, taking into account the principles of pharmacokinetics and pharmacodynamics, can be especially effective in patients with the expectedly changed parameters of pharmacokinetics and in infections caused by bacteria strains with low sensitivity to antibiotics. The review presents a contemporary view of pharmacokinetic and pharmacodynamic profiles of antibacterial drugs most commonly used in pediatrics and their relationship to the clinical efficacy of the administered therapy.

New recommendations for dose equivalent

International Nuclear Information System (INIS)

Bengtsson, G.

1985-01-01

In its report 39, the International Commission on Radiation Units and Measurements (ICRU), has defined four new quantities for the determination of dose equivalents from external sources: the ambient dose equivalent, the directional dose equivalent, the individual dose equivalent, penetrating and the individual dose equivalent, superficial. The rationale behind these concepts and their practical application are discussed. Reference is made to numerical values of these quantities which will be the subject of a coming publication from the International Commission on Radiological Protection, ICRP. (Author)

Repair and dose-response at low doses

International Nuclear Information System (INIS)

Totter, J.R.; Weinberg, A.M.

1977-04-01

The DNA of each individual is subject to formation of some 2-4 x 10 14 ion pairs during the first 30 years of life from background radiation. If a single hit is sufficient to cause cancer, as is implicit in the linear, no-threshold theories, it is unclear why all individuals do not succumb to cancer, unless repair mechanisms operate to remove the damage. We describe a simple model in which the exposed population displays a distribution of repair thresholds. The dose-response at low dose is shown to depend on the shape of the threshold distribution at low thresholds. If the probability of zero threshold is zero, the response at low dose is quadratic. The model is used to resolve a longstanding discrepancy between observed incidence of leukemia at Nagasaki and the predictions of the usual linear hypothesis

Pharmacokinetics, Safety and Tolerability of Melissa officinalis Extract which Contained Rosmarinic Acid in Healthy Individuals: A Randomized Controlled Trial.

Directory of Open Access Journals (Sweden)

Moeko Noguchi-Shinohara

Full Text Available The aim of this study was to evaluate the safety, tolerability and pharmacokinetics of single dose of Melissa officinalis extract which contained rosmarinic acid, including food-effects in healthy individuals. A total of eleven healthy individuals were randomly assigned to treatment arms in the two studies [Study 1 (fasted state and Study 2 (fed state]. Rosmarinic acid in serum was measured by a coulometric detection method using High-Performance Liquid Chromatography electrochemical detector. The serum concentration of total rosmarinic acid peaked at 1 hour after administration of Melissa officinalis extract containing 500mg rosmarinic acid in fasted state, with a maximum serum concentration 162.20 nmol/ L. The area under the curve for intact rosmarinic acid was calculated from the serum concentration-time profile to be 832.13 nmol • hour/ L. Food intake increases area under the curve and delayed time at which the maximum serum concentration. Rosmarinic acid supplementation did not affect liver, kidney, or blood cell function parameters. No adverse event was reported by any of the participants due to the study treatment. Single dose of Melissa officinalis extract containing 500 mg rosmarinic acid appears to be safe and tolerable in healthy individuals. Food intake increased the exposure of rosmarinic acid and delayed absorption of rosmarinic acid in healthy individuals.

CYP2C9 genotype vs. metabolic phenotype for individual drug dosing--a correlation analysis using flurbiprofen as probe drug.

Science.gov (United States)

Vogl, Silvia; Lutz, Roman W; Schönfelder, Gilbert; Lutz, Werner K

2015-01-01

Currently, genotyping of patients for polymorphic enzymes responsible for metabolic elimination is considered a possibility to adjust drug dose levels. For a patient to profit from this procedure, the interindividual differences in drug metabolism within one genotype should be smaller than those between different genotypes. We studied a large cohort of healthy young adults (283 subjects), correlating their CYP2C9 genotype to a simple phenotyping metric, using flurbiprofen as probe drug. Genotyping was conducted for CYP2C9*1, *2, *3. The urinary metabolic ratio MR (concentration of CYP2C9-dependent metabolite divided by concentration of flurbiprofen) determined two hours after flurbiprofen (8.75 mg) administration served as phenotyping metric. Linear statistical models correlating genotype and phenotype provided highly significant allele-specific MR estimates of 0.596 for the wild type allele CYP2C9*1, 0.405 for CYP2C9*2 (68 % of wild type), and 0.113 for CYP2C9*3 (19 % of wild type). If these estimates were used for flurbiprofen dose adjustment, taking 100 % for genotype *1/*1, an average reduction to 84 %, 60 %, 68 %, 43 %, and 19 % would result for genotype *1/*2, *1/*3, *2/*2, *2/*3, and *3/*3, respectively. Due to the large individual variation within genotypes with coefficients of variation ≥ 20 % and supposing the normal distribution, one in three individuals would be out of the average optimum dose by more than 20 %, one in 20 would be 40 % off. Whether this problem also applies to other CYPs and other drugs has to be investigated case by case. Our data for the given example, however, puts the benefit of individual drug dosing to question, if it is exclusively based on genotype.

CYP2C9 genotype vs. metabolic phenotype for individual drug dosing--a correlation analysis using flurbiprofen as probe drug.

Directory of Open Access Journals (Sweden)

Silvia Vogl

Full Text Available Currently, genotyping of patients for polymorphic enzymes responsible for metabolic elimination is considered a possibility to adjust drug dose levels. For a patient to profit from this procedure, the interindividual differences in drug metabolism within one genotype should be smaller than those between different genotypes. We studied a large cohort of healthy young adults (283 subjects, correlating their CYP2C9 genotype to a simple phenotyping metric, using flurbiprofen as probe drug. Genotyping was conducted for CYP2C9*1, *2, *3. The urinary metabolic ratio MR (concentration of CYP2C9-dependent metabolite divided by concentration of flurbiprofen determined two hours after flurbiprofen (8.75 mg administration served as phenotyping metric. Linear statistical models correlating genotype and phenotype provided highly significant allele-specific MR estimates of 0.596 for the wild type allele CYP2C9*1, 0.405 for CYP2C9*2 (68 % of wild type, and 0.113 for CYP2C9*3 (19 % of wild type. If these estimates were used for flurbiprofen dose adjustment, taking 100 % for genotype *1/*1, an average reduction to 84 %, 60 %, 68 %, 43 %, and 19 % would result for genotype *1/*2, *1/*3, *2/*2, *2/*3, and *3/*3, respectively. Due to the large individual variation within genotypes with coefficients of variation ≥ 20 % and supposing the normal distribution, one in three individuals would be out of the average optimum dose by more than 20 %, one in 20 would be 40 % off. Whether this problem also applies to other CYPs and other drugs has to be investigated case by case. Our data for the given example, however, puts the benefit of individual drug dosing to question, if it is exclusively based on genotype.

Solubility of hot fuel particles from Chernobyl--influencing parameters for individual radiation dose calculations.

Science.gov (United States)

Garger, Evgenii K; Meisenberg, Oliver; Odintsov, Oleksiy; Shynkarenko, Viktor; Tschiersch, Jochen

2013-10-15

Nuclear fuel particles of Chernobyl origin are carriers of increased radioactivity (hot particles) and are still present in the atmosphere of the Chernobyl exclusion zone. Workers in the zone may inhale these particles, which makes assessment necessary. The residence time in the lungs and the transfer in the blood of the inhaled radionuclides are crucial for inhalation dose assessment. Therefore, the dissolution of several kinds of nuclear fuel particles from air filters sampled in the Chernobyl exclusion zone was studied. For this purpose filter fragments with hot particles were submersed in simulated lung fluids (SLFs). The activities of the radionuclides (137)Cs, (90)Sr, (239+240)Pu and (241)Am were measured in the SLF and in the residuum of the fragments by radiometric methods after chemical treatment. Soluble fractions as well as dissolution rates of the nuclides were determined. The influence of the genesis of the hot particles, represented by the (137)Cs/(239+240)Pu ratio, on the availability of (137)Cs was demonstrated, whereas the dissolution of (90)Sr, (239+240)Pu and (241)Am proved to be independent of genesis. No difference in the dissolution of (137)Cs and (239+240)Pu was observed for the two applied types of SLF. Increased solubility was found for smaller hot particles. A two-component exponential model was used to describe the dissolution of the nuclides as a function of time. The results were applied for determining individual inhalation dose coefficients for the workers at the Chernobyl construction site. Greater dose coefficients for the respiratory tract and smaller coefficients for the other organs were calculated (compared to ICRP default values). The effective doses were in general lower for the considered radionuclides, for (241)Am even by one order of magnitude. © 2013 Elsevier B.V. All rights reserved.

Critical Dose of Internal Organs Internal Exposure - 13471

Energy Technology Data Exchange (ETDEWEB)

Grigoryan, G.; Amirjanyan, A. [Nuclear and Radiation Safety Centre (Armenia); Grigoryan, N. [Yerevan State Medical University 4Tigran Mets,375010 Yerevan (Armenia)

2013-07-01

The health threat posed by radionuclides has stimulated increased efforts to developed characterization on the biological behavior of radionuclides in humans in all ages. In an effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is assembling a set of age specific biokinetic models for environmentally important radioelements. Radioactive substances in the air, mainly through the respiratory system and digestive tract, is inside the body. Radioactive substances are unevenly distributed in various organs and tissues. Therefore, the degree of damage will depend not only on the dose of radiation have but also on the critical organ, which is the most accumulation of radioactive substances, which leads to the defeat of the entire human body. The main objective of radiation protection, to avoid exceeding the maximum permissible doses of external and internal exposure of a person to prevent the physical and genetic damage people. The maximum tolerated dose (MTD) of radiation is called a dose of radiation a person in uniform getting her for 50 years does not cause changes in the health of the exposed individual and his progeny. The following classification of critical organs, depending on the category of exposure on their degree of sensitivity to radiation: First group: the whole body, gonads and red bone marrow; Second group: muscle, fat, liver, kidney, spleen, gastrointestinal tract, lungs and lens of the eye; The third group: bone, thyroid and skin; Fourth group: the hands, forearms, feet. MTD exposure whole body, gonads and bone marrow represent the maximum exposures (5 rem per year) experienced by people in their normal activities. The purpose of this article is intended dose received from various internal organs of the radionuclides that may enter the body by inhalation, and gastrointestinal tract. The biokinetic model describes the time dependent distribution and excretion of different

Development of Real-Time Measurement of Effective Dose for High Dose Rate Neutron Fields

CERN Document Server

Braby, L A; Reece, W D

2003-01-01

Studies of the effects of low doses of ionizing radiation require sources of radiation which are well characterized in terms of the dose and the quality of the radiation. One of the best measures of the quality of neutron irradiation is the dose mean lineal energy. At very low dose rates this can be determined by measuring individual energy deposition events, and calculating the dose mean of the event size. However, at the dose rates that are normally required for biology experiments, the individual events can not be separated by radiation detectors. However, the total energy deposited in a specified time interval can be measured. This total energy has a random variation which depends on the size of the individual events, so the dose mean lineal energy can be calculated from the variance of repeated measurements of the energy deposited in a fixed time. We have developed a specialized charge integration circuit for the measurement of the charge produced in a small ion chamber in typical neutron irradiation exp...

A comparative analysis of exposure doses between the radiation workers in dental and general hospital

International Nuclear Information System (INIS)

Yang, Nam Hee; Chung, Woon Kwan; Dong, Kyung Rae; Ju, Yong Jin; Song, Ha Jin; Choi, Eun Jin

2015-01-01

Research and investigation is required for the exposure dose of radiation workers to work in the dental hospital as increasing interest in exposure dose of the dental hospital recently accordingly, study aim to minimize radiation exposure by making a follow-up study of individual exposure doses of radiation workers, analyzing the status on individual radiation exposure management, prediction the radiation disability risk levels by radiation, and alerting the workers to the danger of radiation exposure. Especially given the changes in the dental hospital radiation safety awareness conducted the study in order to minimize radiation exposure. This study performed analyses by a comparison between general and dental hospital, comparing each occupation, with the 116,220 exposure dose data by quarter and year of 5,811 subjects at general and dental hospital across South Korea from January 1, 2008 through December 31, 2012. The following are the results obtained by analyzing average values year and quarter. In term of hospital, average doses were significantly higher in general hospitals than detal ones. In terms of job, average doses were higher in radiological technologists the other workers. Especially, they showed statistically significant differences between radiological technologists than dentists. The above-mentioned results indicate that radiation workers were exposed to radiation for the past 5 years to the extent not exceeding the dose limit (maximum 50 mSv y -1 ). The limitation of this study is that radiation workers before 2008 were excluded from the study. Objective evaluation standards did not apply to the work circumstance or condition of each hospital. Therefore, it is deemed necessary to work out analysis criteria that will be used as objective evaluation standard. It will be necessary to study radiation exposure in more precise ways on the basis of objective analysis standard in the future. Should try to minimize the radiation individual dose of

A comparative analysis of exposure doses between the radiation workers in dental and general hospital

Energy Technology Data Exchange (ETDEWEB)

Yang, Nam Hee; Chung, Woon Kwan; Dong, Kyung Rae; Ju, Yong Jin; Song, Ha Jin [Dept. of Nuclear Engineering, Chosun University, Gwangju (Korea, Republic of); Choi, Eun Jin [Dept. of Public Health and Medicine, Dongshin University, Naju (Korea, Republic of)

2015-02-15

Research and investigation is required for the exposure dose of radiation workers to work in the dental hospital as increasing interest in exposure dose of the dental hospital recently accordingly, study aim to minimize radiation exposure by making a follow-up study of individual exposure doses of radiation workers, analyzing the status on individual radiation exposure management, prediction the radiation disability risk levels by radiation, and alerting the workers to the danger of radiation exposure. Especially given the changes in the dental hospital radiation safety awareness conducted the study in order to minimize radiation exposure. This study performed analyses by a comparison between general and dental hospital, comparing each occupation, with the 116,220 exposure dose data by quarter and year of 5,811 subjects at general and dental hospital across South Korea from January 1, 2008 through December 31, 2012. The following are the results obtained by analyzing average values year and quarter. In term of hospital, average doses were significantly higher in general hospitals than detal ones. In terms of job, average doses were higher in radiological technologists the other workers. Especially, they showed statistically significant differences between radiological technologists than dentists. The above-mentioned results indicate that radiation workers were exposed to radiation for the past 5 years to the extent not exceeding the dose limit (maximum 50 mSv y{sup -1}). The limitation of this study is that radiation workers before 2008 were excluded from the study. Objective evaluation standards did not apply to the work circumstance or condition of each hospital. Therefore, it is deemed necessary to work out analysis criteria that will be used as objective evaluation standard. It will be necessary to study radiation exposure in more precise ways on the basis of objective analysis standard in the future. Should try to minimize the radiation individual dose of

Conversion from tooth enamel dose to organ doses for electron spin resonance dosimetry

International Nuclear Information System (INIS)

Takahashi, Fumiaki; Yamaguchi, Yasuhiro; Saito, Kimiaki; Hamada, Tatsuji

2002-01-01

Conversion from tooth enamel dose to organ doses was analyzed to establish a method of retrospective individual dose assessment against external photon exposure by electron spin resonance (ESR) dosimetry. Dose to tooth enamel was obtained by Monte Carlo calculations using a modified MIRD-type phantom with a teeth part. The calculated tooth enamel doses were verified by measurements with thermo-luminescence dosimeters inserted in a physical head phantom. Energy and angular dependences of tooth enamel dose were compared with those of other organ doses. Additional Monte Carlo calculations were performed to study the effect of human model on the tooth enamel dose with a voxel-type phantom, which was based on computed tomography images of the physical phantom. The data derived with the modified MIRD-type phantom were applied to convert from tooth enamel dose to organ doses against external photon exposure in a hypothesized field, where scattered radiation was taken into account. The results indicated that energy distribution of photons incident to a human body is required to evaluate precisely an individual dose based on ESR dosimetry for teeth. (author)

Occupational dose assessment and national dose registry system in Iran

International Nuclear Information System (INIS)

Jafari-Zadeh, M.; Nazeri, F.; Hosseini-Pooya, S. M.; Taheri, M.; Gheshlaghi, F.; Kardan, M. R.; Babakhani, A.; Rastkhah, N.; Yousefi-Nejad, F.; Darabi, M.; Oruji, T.; Gholamali-Zadeh, Z.; Karimi-Diba, J.; Kazemi-Movahed, A. A.; Dashti-Pour, M. R.; Enferadi, A.; Jahanbakhshian, M. H.; Sadegh-Khani, M. R.

2011-01-01

This report presents status of external and internal dose assessment of workers and introducing the structure of National Dose Registry System of Iran (NDRSI). As well as types of individual dosemeters in use, techniques for internal dose assessment are presented. Results obtained from the International Atomic Energy Agency intercomparison programme on measurement of personal dose equivalent H p (10) and consistency of the measured doses with the delivered doses are shown. Also, implementation of dosimetry standards, establishment of quality management system, authorisation and approval procedure of dosimetry service providers are discussed. (authors)

Considerations on the establishment of maximum permissible exposure of man

International Nuclear Information System (INIS)

Jacobi, W.

1974-01-01

An attempt is made in the information lecture to give a quantitative analysis of the somatic radiation risk and to illustrate a concept to fix dose limiting values. Of primary importance is the limiting values. Of primary importance is the limiting value of the radiation exposure to the whole population. By consequential application of the risk concept, the following points are considered: 1) Definition of the risk for radiation late damages (cancer, leukemia); 2) relationship between radiation dose and thus caused radiation risk; 3) radiation risk and the dose limiting values at the time; 4) criteria for the maximum acceptable radiation risk; 5) limiting value which can be expected at the time. (HP/LH) [de

Estimation of eye lens doses received by pediatric interventional cardiologists.

Science.gov (United States)

Alejo, L; Koren, C; Ferrer, C; Corredoira, E; Serrada, A

2015-09-01

Maximum Hp(0.07) dose to the eye lens received in a year by the pediatric interventional cardiologists has been estimated. Optically stimulated luminescence dosimeters were placed on the eyes of an anthropomorphic phantom, whose position in the room simulates the most common irradiation conditions. Maximum workload was considered with data collected from procedures performed in the Hospital. None of the maximum values obtained exceed the dose limit of 20 mSv recommended by ICRP. Copyright © 2015 Elsevier Ltd. All rights reserved.

Population dose commitments due to radioactive releases from nuclear power plant sites in 1982. Volume 4

International Nuclear Information System (INIS)

Baker, D.A.; Peloquin, R.A.

1986-06-01

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1982. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 51 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each site is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments from both liquid and airborne pathways ranged from a high of 30 person-rem to a low of 0.007 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 3 person-rem. The total population dose for all sites was estimated at 130 person-rem for the 100 million people considered at risk. The average individual dose commitment from all pathways on a site basis ranged from a low of 6 x 10 -7 mrem to a high of 0.06 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites

Results for SEAFP-subtask A 10: Assessments of individual and collective doses to the public for routine and accidental releases of tritium and activation products

International Nuclear Information System (INIS)

Raskob, W.

1995-04-01

Dose calculations have been performed for accidental releases of tritium and activation products. Unit releases of 1 GBq per nuclide have been investigated for 31 fusion relevant nuclides. Additionally, unit releases of 1g of tritium and several activated materials have been studied. Under normal operation conditions, dose calculations have been performed for real source terms of tritium and activated materials. The individual dose values at the fence of the site (1 km) as well as the collective dose to the public (from 1 km to 100 km) have been obtained. As site specific parameters are still missing, different so called ''worst case'' release conditions have been applied. To have a first guess of the influence of the release duration on the dose to the Most Exposed Individual (MEI) in the vicinity of a reactor, different release durations, ranging from 1 hour up to 168 hours have been investigated, too. Finally, dose calculations have been performed for mobilisation source terms which take account of deposition and retention in the plant. This has been done for several RPM and APM source terms. The dose values of these final source terms seem to be less than every criteria to start emergency actions, however, some problems e.g. the behaviour of tritium in the plant, remain unsolved. (orig.)

Maximum permissible concentration (MPC) values for spontaneously fissioning radionuclides

International Nuclear Information System (INIS)

Ford, M.R.; Snyder, W.S.; Dillman, L.T.; Watson, S.B.

1976-01-01

The radiation hazards involved in handling certain of the transuranic nuclides that exhibit spontaneous fission as a mode of decay were reaccessed using recent advances in dosimetry and metabolic modeling. Maximum permissible concentration (MPC) values in air and water for occupational exposure (168 hr/week) were calculated for 244 Pu, 246 Cm, 248 Cm, 250 Cf, 252 Cf, 254 Cf, /sup 254m/Es, 255 Es, 254 Fm, and 256 Fm. The half-lives, branching ratios, and principal modes of decay of the parent-daughter members down to a member that makes a negligible contribution to the dose are given, and all daughters that make a significant contribution to the dose to body organs following inhalation or ingestion are included in the calculations. Dose commitments for body organs are also given

The patient dose survey and dose reduction in diagnostic radiology

International Nuclear Information System (INIS)

Dang Thanh Luong; Duong Van Vinh; Ha Ngoc Thach

2000-01-01

This paper presented the results of the patient dose survey in some hospitals in Hanoi from 1995 to 1997. The main investigated types of the X-ray examination were: Chest PA, LAT; Skull PA/AP, LAT; Lumbar spine AP, LAT; and Pelvis AP. The fluctuation of the entrance surface doses (ESD) was too large, even in the same type of X-ray examination and X-ray facility. It was found that the ratio of maximum and minimum ESD were ranged from 1.5 to 18. The mean values of ESD for chest and skull were higher than CEC recommended values, while the mean values of lumbar spine and pelvis were smaller than that of CEC recommended values. The result of dose intercomparison was also reported. Some methods of dose reduction were applied for improving the patient dose in X-ray departments such as a high kV technique, high sensitive screen-film combination. (author)

Problems arising from effects of low radiation doses in early pregnancy

International Nuclear Information System (INIS)

Neumeister, K.

1976-01-01

From 1970 to 1974, 37 expert opinions concerning interruption of pregnancy because of radiation stress of the foetus had to be given at the Centre for Clinical Radiobiology of the Karl-Marx University, Leipzig. In the cases investigated, radiation stress occurred between the first and tenth week of pregnancy at a maximum amount of approximately 20 R. X-ray diagnostic measures had been taken in the abdominal range or a tumour radiotherapy had been made, all in cases of unknown pregnancy. The individual determination of the foetal dose showed that different doses result, depending on the setting technique of photographs, physico-technical conditions and body size. In no case did anamnesis show special features. At the given doses an interruption seemed necessary only in one case (radiotherapy). According to this survey, diagnostic radiation stresses in early pregnancy almost always show radiation doses which, at the present stage of knowledge, do not make an interruption seem necessary. Individual differences of dose values for the same exposures, however, make it necessary to calculate exactly the radiation stress of the foetus in each case and to make the corresponding decision. As recent literature agrees in negating a so-called threshold dose for early damage, it is, apart from genetic considerations, necessary to avoid radiation stresses in early pregnancy for this reason also. In the author's opinion, an indication for an interruption is given at doses above 10 R (see also Hammer-Jacobsen, 1959). At lower radiation stresses, an interruption should be recommended in case of simultaneous additional noxae. This paper communicates the results of the check-ups of children who had been subject to a radiation stress of below 7 R in utero in the above cases. (author)

CONDOS: a model and computer code to estimate population and individual radiation doses to man from the distribution, use, and disposal of consumer products that contain radioactive materials

International Nuclear Information System (INIS)

O'Donnell, F.R.; McKay, L.R.; Burke, O.W.; Clark, F.H.

1975-05-01

A model and computer code (CONDOS) are described that estimate radiation doses to man from distribution, use, and disposal of a variety of consumer products that contain radioactive materials. CONDOS utilizes a generalized format in which the life span of a consumer product is divided into five main stages (distribution, transport, use, disposal, and emergencies) that require descriptions of the activities by which man may be exposed to the product (events) during each stage. These descriptions identify homogeneous groups of exposed persons and, thus, facilitate the selection of individuals who represent the exposed groups. The radiation doses associated with one year of product use to the total body and to selected reference organs and tissues of representative individuals can be estimated for each mode of exposure that is applicable to each event. Summation of the doses to representative individuals yields group and total population doses. An example of the use of CONDOS is given; the radiation doses associated with a hypothetical product are estimated for assumed conditions of exposure. (U.S.)

[The maximum heart rate in the exercise test: the 220-age formula or Sheffield's table?].

Science.gov (United States)

Mesquita, A; Trabulo, M; Mendes, M; Viana, J F; Seabra-Gomes, R

1996-02-01

To determine in the maximum cardiac rate in exercise test of apparently healthy individuals may be more properly estimated through 220-age formula (Astrand) or the Sheffield table. Retrospective analysis of clinical history and exercises test of apparently healthy individuals submitted to cardiac check-up. Sequential sampling of 170 healthy individuals submitted to cardiac check-up between April 1988 and September 1992. Comparison of maximum cardiac rate of individuals studied by the protocols of Bruce and modified Bruce, in interrupted exercise test by fatigue, and with the estimated values by the formulae: 220-age versus Sheffield table. The maximum cardiac heart rate is similar with both protocols. This parameter in normal individuals is better predicted by the 220-age formula. The theoretic maximum cardiac heart rate determined by 220-age formula should be recommended for a healthy, and for this reason the Sheffield table has been excluded from our clinical practice.

A preliminary assessment of individual doses in the environs of Berkeley, Gloucestershire, following the Chernobyl nuclear reactor accident

International Nuclear Information System (INIS)

Nair, S.; Darley, P.J.

1986-06-01

A preliminary assessment has been made of the individual doses to critical group members of the public in the environs of Berkeley arising from fallout resulting from the Chernobyl accident. The assessment was based on measurements of airborne radionuclide concentrations, ground deposition and nuclide concentrations in rainwater, tapwater, grass, milk and green vegetables. The committed effective dose-equivalent was found to be as follows:- Adult - 200 μSv, 1 year old child - 500 μSv, the 10 year old child receiving a dose intermediate between these two values. The estimate accounts only for the nuclides measured and the specific exposure routes considered namely ingestion of milk and vegetables, inhalation and external exposure. However, it is believed that the inclusion of a range of other nuclides of potential significance, which may have been present but not measured, and potential intakes from additional routes is unlikely to increase the above estimates by more than a factor of 2. (author)

Dose-volume complication analysis for visual pathway structures of patients with advanced paranasal sinus tumors

International Nuclear Information System (INIS)

Martel, Mary Kaye; Sandler, Howard M.; Cornblath, Wayne T.; Marsh, Lon H.; Hazuka, Mark B.; Roa, Wilson H.; Fraass, Benedict A.; Lichter, Allen S.

1997-01-01

Purpose: The purpose of the present work was to relate dose and volume information to complication data for visual pathway structures in patients with advanced paranasal sinus tumors. Methods and Materials: Three-dimensional (3D) dose distributions for chiasm, optic nerve, and retina were calculated and analyzed for 20 patients with advanced paranasal sinus malignant tumors. 3D treatment planning with beam's eye view capability was used to design beam and block arrangements, striving to spare the contralateral orbit (to lessen the chance of unilateral blindness) and frequently the ipsilateral orbit (to help prevent bilateral blindness). Point doses, dose-volume histogram analysis, and normal tissue complication probability (NTCP) calculations were performed. Published tolerance doses that indicate significant risk of complications were used as guidelines for analysis of the 3D dose distributions. Results: Point doses, percent volume exceeding a specified published tolerance dose, and NTCP calculations are given in detail for patients with complications versus patients without complications. Two optic nerves receiving maximum doses below the published tolerance dose sustained damage (mild vision loss). Three patients (of 13) without optic nerve sparing and/or chiasm sparing had moderate or severe vision loss. Complication data, including individual patient analysis to estimate overall risk for loss of vision, are given. Conclusion: 3D treatment planning techniques were used successfully to provide bilateral sparing of the globe for most patients. It was more difficult to spare the optic nerves, especially on the ipsilateral side, when prescription dose exceeded the normal tissue tolerance doses. NTCP calculations may be useful in assessing complication risk better than point dose tolerance criteria for the chiasm, optic nerve, and retina. It is important to assess the overall risk of blindness for the patient in addition to the risk for individual visual pathway

Maximum dose angle for oblique incidence on primary beam protective barriers in the design of medical radiation therapy facilities

International Nuclear Information System (INIS)

Fondevila, Damian; Arbiser, Silvio; Sansogne, Rosana; Brunetto, Monica; Dosoretz, Bernardo

2008-01-01

Primary barrier determinations for the shielding of medical radiation therapy facilities are generally made assuming normal beam incidence on the barrier, since this is geometrically the most unfavorable condition for that shielding barrier whenever the occupation line is allowed to run along the barrier. However, when the occupation line (for example, the wall of an adjacent building) runs perpendicular to the barrier (especially roof barrier), then two opposing factors come in to play: increasing obliquity angle with respect to the barrier increases the attenuation, while the distance to the calculation point decreases, hence, increasing the dose. As a result, there exists an angle (α max ) for which the equivalent dose results in a maximum, constituting the most unfavorable geometric condition for that shielding barrier. Based on the usual NCRP Report No. 151 model, this article presents a simple formula for obtaining α max , which is a function of the thickness of the barrier (t E ) and the equilibrium tenth-value layer (TVL e ) of the shielding material for the nominal energy of the beam. It can be seen that α max increases for increasing TVL e (hence, beam energy) and decreases for increasing t E , with a range of variation that goes from 13 to 40 deg for concrete barriers thicknesses in the range of 50-300 cm and most commercially available teletherapy machines. This parameter has not been calculated in the existing literature for radiotherapy facilities design and has practical applications, as in calculating the required unoccupied roof shielding for the protection of a nearby building located in the plane of the primary beam rotation

Maximum dose angle for oblique incidence on primary beam protective barriers in the design of medical radiation therapy facilities.

Science.gov (United States)

Fondevila, Damián; Arbiser, Silvio; Sansogne, Rosana; Brunetto, Mónica; Dosoretz, Bernardo

2008-05-01

Primary barrier determinations for the shielding of medical radiation therapy facilities are generally made assuming normal beam incidence on the barrier, since this is geometrically the most unfavorable condition for that shielding barrier whenever the occupation line is allowed to run along the barrier. However, when the occupation line (for example, the wall of an adjacent building) runs perpendicular to the barrier (especially roof barrier), then two opposing factors come in to play: increasing obliquity angle with respect to the barrier increases the attenuation, while the distance to the calculation point decreases, hence, increasing the dose. As a result, there exists an angle (alpha(max)) for which the equivalent dose results in a maximum, constituting the most unfavorable geometric condition for that shielding barrier. Based on the usual NCRP Report No. 151 model, this article presents a simple formula for obtaining alpha(max), which is a function of the thickness of the barrier (t(E)) and the equilibrium tenth-value layer (TVL(e)) of the shielding material for the nominal energy of the beam. It can be seen that alpha(max) increases for increasing TVL(e) (hence, beam energy) and decreases for increasing t(E), with a range of variation that goes from 13 to 40 deg for concrete barriers thicknesses in the range of 50-300 cm and most commercially available teletherapy machines. This parameter has not been calculated in the existing literature for radiotherapy facilities design and has practical applications, as in calculating the required unoccupied roof shielding for the protection of a nearby building located in the plane of the primary beam rotation.

Patient dose measurement and dose reduction in chest radiography

Directory of Open Access Journals (Sweden)

Milatović Aleksandra A.

2014-01-01

Full Text Available Investigations presented in this paper represent the first estimation of patient doses in chest radiography in Montenegro. In the initial stage of our study, we measured the entrance surface air kerma and kerma area product for chest radiography in five major health institutions in the country. A total of 214 patients were observed. We reported the mean value, minimum and third quartile values, as well as maximum values of surface air kerma and kerma area product of patient doses. In the second stage, the possibilities for dose reduction were investigated. Mean kerma area product values were 0.8 ± 0.5 Gycm2 for the posterior-anterior projection and 1.6 ± 0.9 Gycm2 for the lateral projection. The max/min ratio for the entrance surface air kerma was found to be 53 for the posterior-anterior projection and 88 for the lateral projection. Comparing the results obtained in Montenegro with results from other countries, we concluded that patient doses in our medical centres are significantly higher. Changes in exposure parameters and increased filtration contributed to a dose reduction of up to 36% for posterior-anterior chest examinations. The variability of the estimated dose values points to a significant space for dose reduction throughout the process of radiological practice optimisation.

Preliminary dose assessment of the Chernobyl accident

International Nuclear Information System (INIS)

Hull, A.P.

1987-01-01

From the major accident at Unit 4 of the Chernobyl nuclear power station, a plume of airborne radioactive fission products was initially carried northwesterly toward Poland, thence toward Scandinavia and into Central Europe. Reports of the levels of radioactivity in a variety of media and of external radiation levels were collected in the Department of Energy's Emergency Operations Center and compiled into a data bank. Portions of these and other data which were obtained directly from published and official reports were utilized to make a preliminary assessment of the extent and magnitude of the external dose to individuals downwind from Chernobyl. Radioactive 131 I was the predominant fission product. The time of arrival of the plume and the maximum concentrations of 131 I in air, vegetation and milk and the maximum reported depositions and external radiation levels have been tabulated country by country. A large amount of the total activity in the release was apparently carried to a significant elevation. The data suggest that in areas where rainfall occurred, deposition levels were from ten to one-hundred times those observed in nearby ''dry'' locations. Sufficient spectral data were obtained to establish average release fractions and to establish a reference spectra of the other nuclides in the release. Preliminary calculations indicated that the collective dose equivalent to the population in Scandinavia and Central Europe during the first year after the Chernobyl accident would be about 8 x 10 6 person-rem. From the Soviet report, it appears that a first year population dose of about 2 x 10 7 person-rem (2 x 10 5 Sv) will be received by the population who were downwind of Chernobyl within the U.S.S.R. during the accident and its subsequent releases over the following week. 32 refs., 14 figs., 20 tabs

Dose mapping role in gamma irradiation industry

International Nuclear Information System (INIS)

Noriah Mod Ali; John Konsoh Sangau; Mazni Abd Latif

2002-01-01

In this studies, the role of dosimetry activity in gamma irradiator was discussed. Dose distribution in the irradiator, which is a main needs in irradiator or chamber commissioning. This distribution data were used to confirm the dosimetry parameters i.e. exposure time, maximum and minimum dose map/points, and dose distribution - in which were used as guidelines for optimum product irradiation. (Author)

Dosimetry studies with 32P source and correlation of skin and eye lens doses

International Nuclear Information System (INIS)

Kumar, Munish; Gaonkar, U.P.; Koul, D.K.; Datta, D.; Saxena, S.K.; Kumar, Yogendra; Dash, A.

2018-01-01

Beta particles are one of the major contributors toward skin and eye lens doses at facilities handling beta sources. These sources find applications in industry, pharmaceuticals as well as in brachytherapy applications. The beta particles having maximum (E max ) energy > 0.07 MeV are capable of delivering skin dose whereas beta particles having maximum (E max ) energy > 0.7 MeV may also contribute towards dose to eye lens. Studies are performed using 32 P beta source as its maximum beta energy (E max ) is such that for sources having (E max ) of 1.71 MeV or beyond, there can be substantial contribution towards dose to eye lens even the dose limit recommended for skin is followed

Individualized toxicity-titrated 6-mercaptopurine increments during high-dose methotrexate consolidation treatment of lower risk childhood acute lymphoblastic leukaemia. A Nordic Society of Paediatric Haematology and Oncology (NOPHO) pilot study

DEFF Research Database (Denmark)

Frandsen, Thomas L; Abrahamsson, Jonas; Lausen, Birgitte

2011-01-01

This study explored the feasibility and toxicity of individualized toxicity-titrated 6-mercaptopurine (6MP) dose increments during post-remission treatment with High-dose methotrexate (HDM) (5000 mg/m(2), ×3) in 38 patients with Childhood (ALL). Patients were increased in steps of 25 mg 6MP/m(2...... the remaining patients (P = 0·03). This study shows individualized toxicity-titrated 6MP dosing during consolidation is feasible without increased risk of toxicity....

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-12-15

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

Issues with using radiological exposures as a company performance measure in a low dose environment

International Nuclear Information System (INIS)

Wilkins, Richard I.

2008-01-01

Full text: Collective and maximum individual doses are two measures commonly used as an indicator for measuring Company performance. There is often an expectation for year on year improvements by optimisation of exposures through improved working methods and modernisation of facilities. Eventually a level of exposure can be reached that is no longer easy to measure which makes meaningful trend analysis difficult. The paper discusses the issues that arose at AWE where the majority of exposures are close the limit of detection for the TLD system used. It details the investigation that was carried out when recorded doses where observed to unexpectedly increase significantly. The paper shows the significant effect of a small change in the background radiation levels that are subtracted for each individual dose measurement. Also discussed is the effect of using TLD dosimeter readers that have undergone recent maintenance and are therefore assessing slightly increased exposures. Compounding the apparent increase in gamma dose a slight change in the manufacturing process for the plastic neutron film in the neutron dosimeters also gave an increased neutron exposure measurement which is detailed. The paper concludes with describing the changes that have been made to better ensure reproducibility of the exposure measurements so that any improvements in Company performance can be shown. It also questions the use of Collective Dose as a performance measure which is commonly misused across the industry. (author)

SU-F-T-113: Inherent Functional Dependence of Spinal Cord Doses of Variable Irradiated Volumes in Spine SBRT

Energy Technology Data Exchange (ETDEWEB)

Ma, L; Braunstein, S; Chiu, J [University of California San Francisco, San Francisco, CA (United States); Sahgal, A [Sunnybrook Health Sciences Center, University of Toronto, Toronto, Ontario (Canada)

2016-06-15

Purpose: Spinal cord tolerance for SBRT has been recommended for the maximum point dose level or at irradiated volumes such as 0.35 mL or 10% of contoured volumes. In this study, we investigated an inherent functional relationship that associates these dose surrogates for irradiated spinal cord volumes of up to 3.0 mL. Methods: A hidden variable termed as Effective Dose Radius (EDR) was formulated based on a dose fall-off model to correlate dose at irradiated spinal cord volumes ranging from 0 mL (point maximum) to 3.0 mL. A cohort of 15 spine SBRT cases was randomly selected to derive an EDR-parameterized formula. The mean prescription dose for the studied cases was 21.0±8.0 Gy (range, 10–40Gy) delivered in 3±1 fractions with target volumes of 39.1 ± 70.6 mL. Linear regression and variance analysis were performed for the fitting parameters of variable EDR values. Results: No direct correlation was found between the dose at maximum point and doses at variable spinal cord volumes. For example, Pearson R{sup 2} = 0.643 and R{sup 2}= 0.491 were obtained when correlating the point maximum dose with the spinal cord dose at 1 mL and 3 mL, respectively. However, near perfect correlation (R{sup 2} ≥0.99) was obtained when corresponding parameterized EDRs. Specifically, Pearson R{sup 2}= 0.996 and R{sup 2} = 0.990 were obtained when correlating EDR (maximum point dose) with EDR (dose at 1 mL) and EDR(dose at 3 mL), respectively. As a result, high confidence level look-up tables were established to correlate spinal cord doses at the maximum point to any finite irradiated volumes. Conclusion: An inherent functional relationship was demonstrated for spine SBRT. Such a relationship unifies dose surrogates at variable cord volumes and proves that a single dose surrogate (e.g. point maximum dose) is mathematically sufficient in constraining the overall spinal cord dose tolerance for SBRT.

Emphysema quantification and lung volumetry in chest X-ray equivalent ultralow dose CT - Intra-individual comparison with standard dose CT.

Science.gov (United States)

Messerli, Michael; Ottilinger, Thorsten; Warschkow, René; Leschka, Sebastian; Alkadhi, Hatem; Wildermuth, Simon; Bauer, Ralf W

2017-06-01

To determine whether ultralow dose chest CT with tin filtration can be used for emphysema quantification and lung volumetry and to assess differences in emphysema measurements and lung volume between standard dose and ultralow dose CT scans using advanced modeled iterative reconstruction (ADMIRE). 84 consecutive patients from a prospective, IRB-approved single-center study were included and underwent clinically indicated standard dose chest CT (1.7±0.6mSv) and additional single-energy ultralow dose CT (0.14±0.01mSv) at 100kV and fixed tube current at 70mAs with tin filtration in the same session. Forty of the 84 patients (48%) had no emphysema, 44 (52%) had emphysema. One radiologist performed fully automated software-based pulmonary emphysema quantification and lung volumetry of standard and ultralow dose CT with different levels of ADMIRE. Friedman test and Wilcoxon rank sum test were used for multiple comparison of emphysema and lung volume. Lung volumes were compared using the concordance correlation coefficient. The median low-attenuation areas (LAA) using filtered back projection (FBP) in standard dose was 4.4% and decreased to 2.6%, 2.1% and 1.8% using ADMIRE 3, 4, and 5, respectively. The median values of LAA in ultralow dose CT were 5.7%, 4.1% and 2.4% for ADMIRE 3, 4, and 5, respectively. There was no statistically significant difference between LAA in standard dose CT using FBP and ultralow dose using ADMIRE 4 (p=0.358) as well as in standard dose CT using ADMIRE 3 and ultralow dose using ADMIRE 5 (p=0.966). In comparison with standard dose FBP the concordance correlation coefficients of lung volumetry were 1.000, 0.999, and 0.999 for ADMIRE 3, 4, and 5 in standard dose, and 0.972 for ADMIRE 3, 4 and 5 in ultralow dose CT. Ultralow dose CT at chest X-ray equivalent dose levels allows for lung volumetry as well as detection and quantification of emphysema. However, longitudinal emphysema analyses should be performed with the same scan protocol and

Excel-Based Tool for Pharmacokinetically Guided Dose Adjustment of Paclitaxel.

Science.gov (United States)

Kraff, Stefanie; Lindauer, Andreas; Joerger, Markus; Salamone, Salvatore J; Jaehde, Ulrich

2015-12-01

Neutropenia is a frequent and severe adverse event in patients receiving paclitaxel chemotherapy. The time above a paclitaxel threshold concentration of 0.05 μmol/L (Tc > 0.05 μmol/L) is a strong predictor for paclitaxel-associated neutropenia and has been proposed as a target pharmacokinetic (PK) parameter for paclitaxel therapeutic drug monitoring and dose adaptation. Up to now, individual Tc > 0.05 μmol/L values are estimated based on a published PK model of paclitaxel by using the software NONMEM. Because many clinicians are not familiar with the use of NONMEM, an Excel-based dosing tool was developed to allow calculation of paclitaxel Tc > 0.05 μmol/L and give clinicians an easy-to-use tool. Population PK parameters of paclitaxel were taken from a published PK model. An Alglib VBA code was implemented in Excel 2007 to compute differential equations for the paclitaxel PK model. Maximum a posteriori Bayesian estimates of the PK parameters were determined with the Excel Solver using individual drug concentrations. Concentrations from 250 patients were simulated receiving 1 cycle of paclitaxel chemotherapy. Predictions of paclitaxel Tc > 0.05 μmol/L as calculated by the Excel tool were compared with NONMEM, whereby maximum a posteriori Bayesian estimates were obtained using the POSTHOC function. There was a good concordance and comparable predictive performance between Excel and NONMEM regarding predicted paclitaxel plasma concentrations and Tc > 0.05 μmol/L values. Tc > 0.05 μmol/L had a maximum bias of 3% and an error on precision of 0.05 μmol/L values between both programs was 1%. The Excel-based tool can estimate the time above a paclitaxel threshold concentration of 0.05 μmol/L with acceptable accuracy and precision. The presented Excel tool allows reliable calculation of paclitaxel Tc > 0.05 μmol/L and thus allows target concentration intervention to improve the benefit-risk ratio of the drug. The easy use facilitates therapeutic drug monitoring in

Dose gradient curve: A new tool for evaluating dose gradient.

Science.gov (United States)

Sung, KiHoon; Choi, Young Eun

2018-01-01

Stereotactic radiotherapy, which delivers an ablative high radiation dose to a target volume for maximum local tumor control, requires a rapid dose fall-off outside the target volume to prevent extensive damage to nearby normal tissue. Currently, there is no tool to comprehensively evaluate the dose gradient near the target volume. We propose the dose gradient curve (DGC) as a new tool to evaluate the quality of a treatment plan with respect to the dose fall-off characteristics. The average distance between two isodose surfaces was represented by the dose gradient index (DGI) estimated by a simple equation using the volume and surface area of isodose levels. The surface area was calculated by mesh generation and surface triangulation. The DGC was defined as a plot of the DGI of each dose interval as a function of the dose. Two types of DGCs, differential and cumulative, were generated. The performance of the DGC was evaluated using stereotactic radiosurgery plans for virtual targets. Over the range of dose distributions, the dose gradient of each dose interval was well-characterized by the DGC in an easily understandable graph format. Significant changes in the DGC were observed reflecting the differences in planning situations and various prescription doses. The DGC is a rational method for visualizing the dose gradient as the average distance between two isodose surfaces; the shorter the distance, the steeper the dose gradient. By combining the DGC with the dose-volume histogram (DVH) in a single plot, the DGC can be utilized to evaluate not only the dose gradient but also the target coverage in routine clinical practice.

Ultralow dose CT for pulmonary nodule detection with chest X-ray equivalent dose - a prospective intra-individual comparative study

Energy Technology Data Exchange (ETDEWEB)

Messerli, Michael [University Zurich, Department of Nuclear Medicine, University Hospital Zurich, Zurich (Switzerland); Cantonal Hospital St. Gallen, Division of Radiology and Nuclear Medicine, St. Gallen (Switzerland); Kluckert, Thomas; Knitel, Meinhard; Desbiolles, Lotus; Bauer, Ralf W.; Wildermuth, Simon [Cantonal Hospital St. Gallen, Division of Radiology and Nuclear Medicine, St. Gallen (Switzerland); Waelti, Stephan [Cantonal Hospital St. Gallen, Division of Radiology and Nuclear Medicine, St. Gallen (Switzerland); University of Montreal, Department of Radiology, CHU Sainte-Justine, Montreal, Quebec (Canada); Rengier, Fabian [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Warschkow, Rene [Cantonal Hospital St. Gallen, Department of Surgery, St. Gallen (Switzerland); Alkadhi, Hatem [University Zurich, Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich (Switzerland); Leschka, Sebastian [Cantonal Hospital St. Gallen, Division of Radiology and Nuclear Medicine, St. Gallen (Switzerland); University Zurich, Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich (Switzerland)

2017-08-15

To prospectively evaluate the accuracy of ultralow radiation dose CT of the chest with tin filtration at 100 kV for pulmonary nodule detection. 202 consecutive patients undergoing clinically indicated chest CT (standard dose, 1.8 ± 0.7 mSv) were prospectively included and additionally scanned with an ultralow dose protocol (0.13 ± 0.01 mSv). Standard dose CT was read in consensus by two board-certified radiologists to determine the presence of lung nodules and served as standard of reference (SOR). Two radiologists assessed the presence of lung nodules and their locations on ultralow dose CT. Sensitivity and specificity of the ultralow dose protocol was compared against the SOR, including subgroup analyses of different nodule sizes and types. A mixed effects logistic regression was used to test for independent predictors for sensitivity of pulmonary nodule detection. 425 nodules (mean diameter 3.7 ± 2.9 mm) were found on SOR. Overall sensitivity for nodule detection by ultralow dose CT was 91%. In multivariate analysis, nodule type, size and patients BMI were independent predictors for sensitivity (p < 0.001). Ultralow dose chest CT at 100 kV with spectral shaping enables a high sensitivity for the detection of pulmonary nodules at exposure levels comparable to plain film chest X-ray. (orig.)

Intensity-modulated radiation therapy for nasopharyngeal carcinoma parotid sparing with euivalent uiform dose optimization

International Nuclear Information System (INIS)

Yue Weiyou; Dai Jianrong; Gao Li

2006-01-01

Objective: The aim of this study was to evaluate the role of an euivalent uiform dose (EUD) based optimization algorithm in sparing the parotids of patients with nasopharyngeal carcinoma (NPC) when they are treated with intensity-modulated radiation therapy (IMRT). Methods: 12 patients were randomly selected from the NPC patients who received IMRT treatments. For these patients, the treatment plans were designed with physical optimization constraints (dose/dose-volume constraints). Based on these plans, new plans were designed through replacing the physical constraints with maximum EUD for parotids, while keeping the physical objectives for targets and other organs at risk(OARs) unchanged. Comparison was then made between the new plan, which had EUD constraints to parotids, and the former for each individual patient. Results: While maintaining the dose to the targets and the other OARs un- changed, optimization with EUD constraints to parotids decreased the mean dose and V 30 of parotids significantly, simultaneously, the dose of target volume and other organs at risk keep stable, the values of probability were less than 0.05 by T-test. Conclusions: The doses to parotids can be reduced through optimization with EUD constraints. This finding is quite helpful to reduce the occurrence rate of parotid complications, and to provide spaces for escalating target dose. (authors)

Calculation of the individual effective dose equivalent in Italy following the Chernobyl accident

International Nuclear Information System (INIS)

Lotfi, M.; Mancioppi, S.; Piermattei, S.; Tommasino, L.; Azimi-Garakani, D.

1991-01-01

Estimates are presented here for the individual effective dose equivalents (EDE) from dietary intake of radiocaesium-contaminated food by the average Italian consumer in different age groups. Food items of consumption rate greater than 50kg/y were included in the food basket studies. In view of the pattern of food consumption in Italy, the radiocaesium concentrations of foodstuffs such as milk, milk products, bread, pasta, meat fruit, vegetables and babyfoods were measured between January 1987 and December 1988 inclusive. These measurements were carried out mainly by the environmental radioactivity laboratories in three administrative districts of Italy. The results show that the total individual EDE values received in 1987 from foodstuffs were around 175, 110 and 70 μSv/year for adults, children (up to 10 years old) and infants (up to one year old), respectively. The corresponding values for 1988 are about 15, 10 and 20 μSv/year, respectively. The EDE committed in the latter half relative to the first half of 1987 was a factor of 2.5 and 3 less for adults and children, respectively, and a factor of about 2 for infants. In 1988, no significant change was observed in EDE values during the year. (author)

Dose prescription complexity versus tumor control probability in biologically conformal radiotherapy

International Nuclear Information System (INIS)

South, C. P.; Evans, P. M.; Partridge, M.

2009-01-01

The technical feasibility and potential benefits of voxel-based nonuniform dose prescriptions for biologically heterogeneous tumors have been widely demonstrated. In some cases, an ''ideal'' dose prescription has been generated by individualizing the dose to every voxel within the target, but often this voxel-based prescription has been discretized into a small number of compartments. The number of dose levels utilized and the methods used for prescribing doses and assigning tumor voxels to different dose compartments have varied significantly. The authors present an investigation into the relationship between the complexity of the dose prescription and the tumor control probability (TCP) for a number of these methods. The linear quadratic model of cell killing was used in conjunction with a number of modeled tumors heterogeneous in clonogen density, oxygenation, or proliferation. Models based on simple mathematical functions, published biological data, and biological image data were investigated. Target voxels were assigned to dose compartments using (i) simple rules based on the initial biological distribution, (ii) iterative methods designed to maximize the achievable TCP, or (iii) methods based on an ideal dose prescription. The relative performance of the simple rules was found to depend on the form of heterogeneity of the tumor, while the iterative and ideal dose methods performed comparably for all models investigated. In all cases the maximum achievable TCP was approached within the first few (typically two to five) compartments. Results suggest that irrespective of the pattern of heterogeneity, the optimal dose prescription can be well approximated using only a few dose levels but only if both the compartment boundaries and prescribed dose levels are well chosen.

Creation and clinical application of real-time dose monitor using dose area product meter

International Nuclear Information System (INIS)

Matsubara, Kosuke; Uoyama, Yoshinori; Iida, Hiroji; Mizushima, Takashi

2004-01-01

The management of patient dose has become more of an issue in recent years. Dose can be determined non-invasively and in real time through the use of a dose area product meter, but it is the area dose value that is obtained. Therefore, we created a program that estimates entrance skin dose (ESD) in real time from area dose values obtained during procedures. We used Microsoft Visual C++ 6.0 (Standard Edition) for the programming language and C language for the programming environment. The value was a maximum 285.4 mGy at ileus tube insertion when measuring ESD for radiography of the digestive organ and non-vascular type interventional radiology (IVR) using the created program and seeking the average according to the procedures. The program that we created can be considered valid for monitoring ESD correctly and in real time. (author)

Dose individualization in PharmDIS-e

NARCIS (Netherlands)

Proost, JH; Punt, NC

2003-01-01

Individualized dosage regimen calculations require knowledge on the pharmacokinetic and pharmacodynamic properties of the drug and the characteristics of the patient. A PK-PD-based dosage regimen is not easily and generally applicable, mainly because the combination of available PK parameters and

Site-specific parameter values for the Nuclear Regulatory Commission's food pathway dose model

International Nuclear Information System (INIS)

Hamby, D.M.

1992-01-01

Routine operations at the Savannah River Site (SRS) in Western South Carolina result in radionuclide releases to the atmosphere and to the Savannah River. The resulting radiation doses to the off-site maximum individual and the off-site population within 80 km of the SRS are estimated on a yearly basis. These estimates are currently generated using dose models prescribed for the commercial nuclear power industry by the Nuclear Regulatory Commission (NRC). The NRC provides default values for dose-model parameters for facilities without resources to develop site-specific values. A survey of land- and water-use characteristics for the Savannah River area has been conducted to determine site-specific values for water recreation, consumption, and agricultural parameters used in the NRC Regulatory Guide 1.109 (1977) dosimetric models. These site parameters include local characteristics of meat, milk, and vegetable production; recreational and commercial activities on the Savannah River; and meat, milk, vegetable, and seafood consumption rates. This paper describes how parameter data were obtained at the Savannah River Site and the impacts of such data on off-site dose. Dose estimates using site-specific parameter values are compared to estimates using the NRC default values

Assessment of effectiveness of geologic isolation systems. ARRRG and FOOD: computer programs for calculating radiation dose to man from radionuclides in the environment

International Nuclear Information System (INIS)

Napier, B.A.; Roswell, R.L.; Kennedy, W.E. Jr.; Strenge, D.L.

1980-06-01

The computer programs ARRRG and FOOD were written to facilitate the calculation of internal radiation doses to man from the radionuclides in the environment and external radiation doses from radionuclides in the environment. Using ARRRG, radiation doses to man may be calculated for radionuclides released to bodies of water from which people might obtain fish, other aquatic foods, or drinking water, and in which they might fish, swim or boat. With the FOOD program, radiation doses to man may be calculated from deposition on farm or garden soil and crops during either an atmospheric or water release of radionuclides. Deposition may be either directly from the air or from irrigation water. Fifteen crop or animal product pathways may be chosen. ARRAG and FOOD doses may be calculated for either a maximum-exposed individual or for a population group. Doses calculated are a one-year dose and a committed dose from one year of exposure. The exposure is usually considered as chronic; however, equations are included to calculate dose and dose commitment from acute (one-time) exposure. The equations for calculating internal dose and dose commitment are derived from those given by the International Commission on Radiological Protection (ICRP) for body burdens and Maximum Permissible Concentration (MPC) of each radionuclide. The radiation doses from external exposure to contaminated farm fields or shorelines are calculated assuming an infinite flat plane source of radionuclides. A factor of two is included for surface roughness. A modifying factor to compensate for finite extent is included in the shoreline calculations

Assessment of effectiveness of geologic isolation systems. ARRRG and FOOD: computer programs for calculating radiation dose to man from radionuclides in the environment

Energy Technology Data Exchange (ETDEWEB)

Napier, B.A.; Roswell, R.L.; Kennedy, W.E. Jr.; Strenge, D.L.

1980-06-01

The computer programs ARRRG and FOOD were written to facilitate the calculation of internal radiation doses to man from the radionuclides in the environment and external radiation doses from radionuclides in the environment. Using ARRRG, radiation doses to man may be calculated for radionuclides released to bodies of water from which people might obtain fish, other aquatic foods, or drinking water, and in which they might fish, swim or boat. With the FOOD program, radiation doses to man may be calculated from deposition on farm or garden soil and crops during either an atmospheric or water release of radionuclides. Deposition may be either directly from the air or from irrigation water. Fifteen crop or animal product pathways may be chosen. ARRAG and FOOD doses may be calculated for either a maximum-exposed individual or for a population group. Doses calculated are a one-year dose and a committed dose from one year of exposure. The exposure is usually considered as chronic; however, equations are included to calculate dose and dose commitment from acute (one-time) exposure. The equations for calculating internal dose and dose commitment are derived from those given by the International Commission on Radiological Protection (ICRP) for body burdens and Maximum Permissible Concentration (MPC) of each radionuclide. The radiation doses from external exposure to contaminated farm fields or shorelines are calculated assuming an infinite flat plane source of radionuclides. A factor of two is included for surface roughness. A modifying factor to compensate for finite extent is included in the shoreline calculations.

Dose due to man-made radionuclides in terrestrial wild foods near Sellafield

International Nuclear Information System (INIS)

Fulker, M.J.; Jackson, D.; McKay, K.; John, C.; Leonard, D.R.P.

1998-01-01

Radiological dose implications for consumers of wild foods around Sellafield have been assessed. Habits were surveyed from 72 households, mostly within a few kilometres of Sellafield. A few people were included who lived further away but collect wild foods close to Sellafield. Dose estimates were based on measured gamma emitters, as well as 239 Pu, 241 Am, 14 C and 129 I in selected samples. In all cases, doses were dominated by 137 Cs. One infant was identified who consumed wild food, giving an estimated effective dose of 0.3 μSv a -1 . In the age group 2 to 10 years a mean dose of 0.51 μSv a -1 , and a maximum of 2.8 μSv a -1 , were estimated. Intakes by adults were higher and resulted in more radiologically significant doses. The extreme individual received a dose of 32 μSv a -1 largely due to consumption of honey that included contributions from the Chernobyl accident, and hedgerow fruits. This is comparable to doses to the critical group for consumption of conventional agricultural produce close to the Sellafield site. The 97.5th percentile dose, for all age groups of consumers taken together, was 16.6 μSv a -1 , or 6.2 μSv a -1 if the contributions from Chernobyl are excluded. Considering the contributions from different foods to the whole group of 181 wild food consumers, the rank order is honey, blackberries and venison. (author)

Atomic structure from large-area, low-dose exposures of materials: A new route to circumvent radiation damage

Energy Technology Data Exchange (ETDEWEB)

Meyer, J.C., E-mail: jannik.meyer@univie.ac.at; Kotakoski, J.; Mangler, C.

2014-10-15

Beam-induced structural modifications are a major nuisance in the study of materials by high-resolution electron microscopy. Here, we introduce a new approach to circumvent the radiation damage problem by a statistical treatment of large, noisy, low-dose data sets of non-periodic configurations (e.g. defects) in the material. We distribute the dose over a mixture of different defect structures at random positions and with random orientations, and recover representative model images via a maximum likelihood search. We demonstrate reconstructions from simulated images at such low doses that the location of individual entities is not possible. The approach may open a route to study currently inaccessible beam-sensitive configurations. - Highlights: • A new approach to circumvent radiation damage. • Statistical treatment of large noisy data sets. • Analysis of radiation sensitive material defects.

Recommendations to the Technical Steering Panel regarding approach for estimating individual radiation doses resulting from releases of radionuclides to the Columbia River

International Nuclear Information System (INIS)

Napier, B.A.; Brothers, A.J.

1992-07-01

At the direction of the Technical Steering Panel (TSP) of the Hanford Environmental Dose Reconstruction (HEDR) Project, Battelle staff have reviewed and analyzed available data regarding possible historical radiation doses to individuals resulting from radionuclide releases to the Columbia River. The objective of this review was to recommend to the TSP the spatial and temporal scope and level of effort on Columbia River work to most effectively extend work performed in Phase I of the project (PNL 1991a, PNL 1991b) to meet the project objectives. A number of options were analyzed. Four stretches of the Columbia River and adjacent Pacific coastal waters were defined and investigated for four time periods. Radiation doses arising from ten potentially major exposure pathways were evaluated for each of the time/location combinations, and several alternative methods were defined for estimating the doses from each pathway. Preliminary cost estimates were also developed for implementing dose estimation activities for each of the possible combinations

An individualized radiation dose escalation trial in non-small cell lung cancer based on FDG-PET imaging

Energy Technology Data Exchange (ETDEWEB)

Wanet, Marie; Goossens, Samuel; Lee, John Aldo; Janssens, Guillaume; Bol, Anne; Geets, Xavier [Universite Catholique de Louvain, Center of Molecular Imaging, Radiotherapy and Oncology (MIRO), Institut de Recherche Experimentale et Clinique, Brussels (Belgium); Delor, Antoine [Cliniques Universitaires Saint-Luc, Department of Radiation Oncology, Brussels (Belgium); Hanin, Francois-Xavier [Cliniques Universitaires Saint-Luc, Department of Nuclear Medicine, Brussels (Belgium); Ghaye, Benoit [Cliniques Universitaires Saint-Luc, Department of Radiology, Brussels (Belgium); Maanen, Aline van [Cliniques Universitaires Saint-Luc, Statistical Support Unit, Cancer Centre, Brussels (Belgium); Remouchamps, Vincent; Clermont, Christian [Clinique et Maternite Sainte Elisabeth, Department of Radiation Oncology, CHU UCL Namur (Belgium)

2017-10-15

The aim of the study was to assess the feasibility of an individualized 18F fluorodeoxyglucose positron emission tomography (FDG-PET)-guided dose escalation boost in non-small cell lung cancer (NSCLC) patients and to assess its impact on local tumor control and toxicity. A total of 13 patients with stage II-III NSCLC were enrolled to receive a dose of 62.5 Gy in 25 fractions to the CT-based planning target volume (PTV; primary tumor and affected lymph nodes). The fraction dose was increased within the individual PET-based PTV (PTV{sub PET}) using intensity modulated radiotherapy (IMRT) with a simultaneous integrated boost (SIB) until the predefined organ-at-risk (OAR) threshold was reached. Tumor response was assessed during follow-up by means of repeat FDG-PET/computed tomography. Acute and late toxicity were recorded and classified according to the CTCAE criteria (Version 4.0). Local progression-free survival was determined using the Kaplan-Meier method. The average dose to PTV{sub PET} reached 89.17 Gy for peripheral and 75 Gy for central tumors. After a median follow-up period of 29 months, seven patients were still alive, while six had died (four due to distant progression, two due to grade 5 toxicity). Local progression was seen in two patients in association with further recurrences. One and 2-year local progression free survival rates were 76.9% and 52.8%, respectively. Three cases of acute grade 3 esophagitis were seen. Two patients with central tumors developed late toxicity and died due to severe hemoptysis. These results suggest that a non-uniform and individualized dose escalation based on FDG-PET in IMRT delivery is feasible. The doses reached were higher in patients with peripheral compared to central tumors. This strategy enables good local control to be achieved at acceptable toxicity rates. However, dose escalation in centrally located tumors with direct invasion of mediastinal organs must be performed with great caution in order to avoid severe

Late effects of low doses and dose rates

International Nuclear Information System (INIS)

Paretzke, H.G.

1980-01-01

This paper outlines the spectrum of problems and approaches used in work on the derivation of quantitative prognoses of late effects in man of low doses and dose rates. The origins of principal problems encountered in radiation risks assessments, definitions and explanations of useful quantities, methods of deriving risk factors from biological and epidemiological data, and concepts of risk evaluation and problems of acceptance are individually discussed

Dose-mapping distribution around MNSR

CERN Document Server

Jamal, M H

2002-01-01

The aim of this study is to establish the dose-rate map through the determination of radiological dose-rate levels in reactor hall, adjacent rooms, and outside the MNSR facility. Controlling dose rate to reactor operating personnel , dose map was established. The map covers time and distances in the reactor hall, during reactor operation at nominal power. Different measurement of dose rates in other areas of the reactor buildings was established. The maximum dose rate, during normal operation of the MNSR was 40 and 21 Sv/hr on the top of the reactor and near the pool fence, respectively. Whereas, gamma and neutron doses have not exceeded natural background in all rooms adjacent to the reactor hall or nearly buildings. The relation between the dose rate for gamma rays and neutron flux at the top of cover of reactor pool was studied as well. It was found that this relation is linear.

Dose-mapping distribution around MNSR

International Nuclear Information System (INIS)

Jamal, M. H.; Khamis, I.

2002-12-01

The aim of this study is to establish the dose-rate map through the determination of radiological dose-rate levels in reactor hall, adjacent rooms, and outside the MNSR facility. Controlling dose rate to reactor operating personnel , dose map was established. The map covers time and distances in the reactor hall, during reactor operation at nominal power. Different measurement of dose rates in other areas of the reactor buildings was established. The maximum dose rate, during normal operation of the MNSR was 40 and 21 Sv/hr on the top of the reactor and near the pool fence, respectively. Whereas, gamma and neutron doses have not exceeded natural background in all rooms adjacent to the reactor hall or nearly buildings. The relation between the dose rate for gamma rays and neutron flux at the top of cover of reactor pool was studied as well. It was found that this relation is linear. (author)

Patch test concentrations (doses in mg/cm(2) ) for the 12 non-mix fragrance substances regulated by European legislation

DEFF Research Database (Denmark)

Bruze, Magnus; Svedman, Cecilia; Andersen, Klaus Ejner

2012-01-01

Background. According to EU legislation, 26 fragrance substance allergens must be labelled on cosmetic products. For 12 of them, the optimal patch test concentration/dose has not been evaluated. Objectives. To establish the optimal patch test doses in mg/cm(2) for the 12 fragrance substances......, it is recommended that half of the maximum patch test dose (mg/cm(2) ) be used for aimed and screening patch testing....... that are not included in fragrance mix I or II in the European baseline patch test series. Materials and Methods. Patch testing with the 12 fragrance substances was performed in a stepwise manner encompassing up to five rounds in at least 100 dermatitis patients for each round. Before patch testing, an individual...

Radiation dose considerations by intra-individual Monte Carlo simulations in dual source spiral coronary computed tomography angiography with electrocardiogram-triggered tube current modulation and adaptive pitch

Energy Technology Data Exchange (ETDEWEB)

May, Matthias S.; Kuettner, Axel; Lell, Michael M.; Wuest, Wolfgang; Scharf, Michael; Uder, Michael [University of Erlangen, Department of Radiology, Erlangen (Germany); Deak, Paul; Kalender, Willi A. [University of Erlangen, Department of Medical Physics, Erlangen (Germany); Keller, Andrea K.; Haeberle, Lothar [University of Erlangen, Department of Medical Informatics, Biometry and Epidemiology, Erlangen (Germany); Achenbach, Stephan; Seltmann, Martin [University of Erlangen, Department of Cardiology, Erlangen (Germany)

2012-03-15

To evaluate radiation dose levels in patients undergoing spiral coronary computed tomography angiography (CTA) on a dual-source system in clinical routine. Coronary CTA was performed for 56 patients with electrocardiogram-triggered tube current modulation (TCM) and heart-rate (HR) dependent pitch adaptation. Individual Monte Carlo (MC) simulations were performed for dose assessment. Retrospective simulations with constant tube current (CTC) served as reference. Lung tissue was segmented and used for organ and effective dose (ED) calculation. Estimates for mean relative ED was 7.1 {+-} 2.1 mSv/100 mAs for TCM and 12.5 {+-} 5.3 mSv/100 mAs for CTC (P < 0.001). Relative dose reduction at low HR ({<=}60 bpm) was highest (49 {+-} 5%) compared to intermediate (60-70 bpm, 33 {+-} 12%) and high HR (>70 bpm, 29 {+-} 12%). However lowest ED is achieved at high HR (5.2 {+-} 1.5 mSv/100 mAs), compared with intermediate (6.7 {+-} 1.6 mSv/100 mAs) and low (8.3 {+-} 2.1 mSv/100 mAs) HR when automated pitch adaptation is applied. Radiation dose savings up to 52% are achievable by TCM at low and regular HR. However lowest ED is attained at high HR by pitch adaptation despite inferior radiation dose reduction by TCM. circle Monte Carlo simulations allow for individual radiation dose calculations. (orig.)

Radiation dose considerations by intra-individual Monte Carlo simulations in dual source spiral coronary computed tomography angiography with electrocardiogram-triggered tube current modulation and adaptive pitch

International Nuclear Information System (INIS)

May, Matthias S.; Kuettner, Axel; Lell, Michael M.; Wuest, Wolfgang; Scharf, Michael; Uder, Michael; Deak, Paul; Kalender, Willi A.; Keller, Andrea K.; Haeberle, Lothar; Achenbach, Stephan; Seltmann, Martin

2012-01-01

To evaluate radiation dose levels in patients undergoing spiral coronary computed tomography angiography (CTA) on a dual-source system in clinical routine. Coronary CTA was performed for 56 patients with electrocardiogram-triggered tube current modulation (TCM) and heart-rate (HR) dependent pitch adaptation. Individual Monte Carlo (MC) simulations were performed for dose assessment. Retrospective simulations with constant tube current (CTC) served as reference. Lung tissue was segmented and used for organ and effective dose (ED) calculation. Estimates for mean relative ED was 7.1 ± 2.1 mSv/100 mAs for TCM and 12.5 ± 5.3 mSv/100 mAs for CTC (P 70 bpm, 29 ± 12%). However lowest ED is achieved at high HR (5.2 ± 1.5 mSv/100 mAs), compared with intermediate (6.7 ± 1.6 mSv/100 mAs) and low (8.3 ± 2.1 mSv/100 mAs) HR when automated pitch adaptation is applied. Radiation dose savings up to 52% are achievable by TCM at low and regular HR. However lowest ED is attained at high HR by pitch adaptation despite inferior radiation dose reduction by TCM. circle Monte Carlo simulations allow for individual radiation dose calculations. (orig.)

A real time dose monitoring and dose reconstruction tool for patient specific VMAT QA and delivery

International Nuclear Information System (INIS)

Tyagi, Neelam; Yang Kai; Gersten, David; Yan Di

2012-01-01

Purpose: To develop a real time dose monitoring and dose reconstruction tool to identify and quantify sources of errors during patient specific volumetric modulated arc therapy (VMAT) delivery and quality assurance. Methods: The authors develop a VMAT delivery monitor tool called linac data monitor that connects to the linac in clinical mode and records, displays, and compares real time machine parameters with the planned parameters. A new measure, called integral error, keeps a running total of leaf overshoot and undershoot errors in each leaf pair, multiplied by leaf width, and the amount of time during which the error exists in monitor unit delivery. Another tool reconstructs Pinnacle 3 ™ format delivered plan based on the saved machine logfile and recalculates actual delivered dose in patient anatomy. Delivery characteristics of various standard fractionation and stereotactic body radiation therapy (SBRT) VMAT plans delivered on Elekta Axesse and Synergy linacs were quantified. Results: The MLC and gantry errors for all the treatment sites were 0.00 ± 0.59 mm and 0.05 ± 0.31°, indicating a good MLC gain calibration. Standard fractionation plans had a larger gantry error than SBRT plans due to frequent dose rate changes. On average, the MLC errors were negligible but larger errors of up to 6 mm and 2.5° were seen when dose rate varied frequently. Large gantry errors occurred during the acceleration and deceleration process, and correlated well with MLC errors (r= 0.858, p= 0.0004). PTV mean, minimum, and maximum dose discrepancies were 0.87 ± 0.21%, 0.99 ± 0.59%, and 1.18 ± 0.52%, respectively. The organs at risk (OAR) doses were within 2.5%, except some OARs that showed up to 5.6% discrepancy in maximum dose. Real time displayed normalized total positive integral error (normalized to the total monitor units) correlated linearly with MLC (r= 0.9279, p < 0.001) and gantry errors (r= 0.742, p= 0.005). There is a strong correlation between total integral

RADIATION HYGIENIC MONITORING AND ASSESSMENT OF POPULATION DOSES IN RADIOACTIVELY CONTAMINATED AREAS OF TULA REGION