PRACTICAL METHODS FOR INTERNAL DOSE ASSESSMENT FOR RADIOIODINE INTAKE AFTER THYROID BLOCKING: CLASSIFICATION OF DEGREE OF BLOCKAGE AND DETERMINATION OF INSENSITIVE MEASUREMENT POINT

2019 ◽  
Vol 187 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Tae-Eun Kwon ◽  
MinSeok Park ◽  
Gyu-Hwan Jung ◽  
Yoonsun Chung ◽  
Wi-Ho Ha ◽  
...  
Keyword(s):  
Dose Assessment ◽  
Internal Dose ◽  
Urine Excretion ◽  
Normal Thyroid ◽  
Considerable Uncertainty ◽  
Biokinetic Model ◽  
Dosimetric Data ◽  
Dose Coefficients

Abstract Iodine thyroid blocking (ITB) suppresses the uptake of iodine to the thyroid and reduces internal doses after radioiodine intake; however, its disturbance of thyroid biokinetics causes considerable uncertainty in the use of dosimetric data intended for assessment of unblocked normal thyroid. To more accurately assess internal dose after ITB, practical dosimetry methods were proposed that consider the ITB effect in a dosimetric manner. A method using the ratio of urine excretion to thyroid retention activity was proposed to retrospectively determine individual-specific ITB levels; bioassay functions and dose coefficients corresponding to ITB levels were calculated separately using the latest biokinetic model and fundamental data. Moreover, insensitive measurement points of time, which led to similar results regardless of ITB level, were determined based on the dose per unit content. Proposed insensitive points for inhalation of vapour forms and particulate forms, respectively, were 1.5 days and 2 days after exposure.

scholarly journals Uncertainty quantification of bioassay functions for the internal dosimetry of radioiodine

2020 ◽  
Vol 61 (6) ◽  
pp. 860-870
Author(s):  
Tae-Eun Kwon ◽  
Yoonsun Chung ◽  
Jaeryong Yoo ◽  
Wi-Ho Ha ◽  
Minsu Cho
Keyword(s):  
Measurement Data ◽  
Dose Assessment ◽  
Internal Dosimetry ◽  
High Dose ◽  
Radiological Protection ◽  
Retention Function ◽  
Internal Dose ◽  
Actual Measurement ◽  
Monte Carlo Simulation Technique ◽  
Biokinetic Model

Abstract Bioassay functions, which are provided by the International Commission on Radiological Protection, are used to estimate the intake activity of radionuclides; however, they include considerable uncertainties in terms of the internal dosimetry for a particular individual. During a practical internal dose assessment, the uncertainty in the bioassay function is generally not introduced because of the difficulty in quantification. Therefore, to clarify the existence of uncertainty in the bioassay function and provide dosimetrists with an insight into this uncertainty, this study attempted to quantify the uncertainty in the thyroid retention function used for radioiodine exposure. The uncertainty was quantified using a probabilistic estimation of the thyroid retention function through the propagation of the distribution of biokinetic parameters by the Monte Carlo simulation technique. The uncertainties in the thyroid retention function, expressed in terms of the scattering factor, were in the ranges of 1.55–1.60 and 1.40–1.50 for within 24 h and after 24 h, respectively. In addition, the thyroid retention function within 24 h was compared with actual measurement data to confirm the uncertainty due to the use of first-order kinetics in the biokinetic model calculation. Significantly higher thyroid uptakes (by a factor of 1.9) were observed in the actual measurements. This study indicates that consideration of the uncertainty in the thyroid retention function can avoid a significant over- and under-estimation of the internal dose, particularly when a high dose is predicted.

scholarly journals Radiopharmacokinetic Modelling and Radiation Dose Assessment of 223ra Used for Treatment of Metastatic Castration Resistant Prostate Cancer

2020 ◽  
Author(s):  
Vera Höllriegl ◽  
Nina Petoussi-Henss ◽  
Juan Camilo Ocampo Ramos ◽  
Wei Bo Li
Keyword(s):  
Prostate Cancer ◽  
Dose Assessment ◽  
Radiological Protection ◽  
Bolus Administration ◽  
Time Activity ◽  
Biokinetic Model ◽  
Castration Resistant ◽  
Red Marrow ◽  
Dose Coefficients ◽  
Modelling Study

Abstract Purpose Ra-223-Dichloride (223Ra, Xofigo®) is used for treatment of patients suffering from castration-resistant metastatic prostate cancer. The objective of this work was to apply the most recent biokinetic model for radium and its progeny and dosimetric framework developed by the International Commission on Radiological Protection (ICRP) and to show their radiopharmacokinetic behaviour. Organ absorbed and equivalent doses after intravenous injection of 223Ra were estimated and compared to clinical data and other modelling study. Methods The most recent ICRP systemic biokinetic model of 223Ra and its progeny as well as the ICRP human alimentary tract model were applied for the radiopharmacokinetic modelling of Xofigo® biodistribution in patients after bolus administration. Independent kinetics was assumed for the progeny of 223Ra. The time activity curves for 223Ra were modelled and the time integrated activity coefficients, in the source regions for each progeny were determined. For estimating the organ absorbed doses, the Specific Absorbed Fractions (SAF) and dosimetric framework of ICRP were used together with the aforementioned values to estimate the organ absorbed and equivalent doses. Results The distribution of 223Ra after injection showed a rapid plasma clearance and a low urinary excretion. Main elimination was via faeces. Bone retention was found to be about 30% at 4 h post-injection. Similar tendencies were observed in clinic trials. The highest absorbed dose coefficients were found for bone endosteum, liver, and red marrow, followed by kidneys and colon. Conclusion The biokinetic modelling of 223Ra and its progeny may help to predict their distributions in patients after administration of Xofigo®. The organ dose coefficients of this work showed some variation to the values from clinical studies and of a previous compartmental modelling study. The dose to the bone endosteum was found to be lower by a factor of ca. 3 than previously estimated.

scholarly journals EURADOS work on internal dosimetry

2018 ◽  
Vol 47 (3-4) ◽  
pp. 75-82 ◽  
Author(s):  
B. Breustedt ◽  
E. Blanchardon ◽  
C-M. Castellani ◽  
G. Etherington ◽  
D. Franck ◽  
...  
Keyword(s):  
Dose Assessment ◽  
Assessment Process ◽  
Internal Dosimetry ◽  
Biokinetic Model ◽  
Intercomparison Exercises ◽  
Training Courses ◽  
Dose Coefficients ◽  
Sensitive Parameters ◽  
Structured Approach ◽  
Technical Recommendations

European Radiation Dosimetry Group (EURADOS) Working Group 7 is a network on internal dosimetry that brings together researchers from more than 60 institutions in 21 countries. The work of the group is organised into task groups that focus on different aspects, such as development and implementation of biokinetic models (e.g. for diethylenetriamine penta-acetic acid decorporation therapy), individual monitoring and the dose assessment process, Monte Carlo simulations for internal dosimetry, uncertainties in internal dosimetry, and internal microdosimetry. Several intercomparison exercises and training courses have been organised. The IDEAS guidelines, which describe – based on the International Commission on Radiological Protection’s (ICRP) biokinetic models and dose coefficients – a structured approach to the assessment of internal doses from monitoring data, are maintained and updated by the group. In addition, Technical Recommendations for Monitoring Individuals for Occupational Intakes of Radionuclides have been elaborated on behalf of the European Commission, DG-ENER (TECHREC Project, 2014–2016, coordinated by EURADOS). Quality assurance of the ICRP biokinetic models by calculation of retention and excretion functions for different scenarios has been performed and feedback was provided to ICRP. An uncertainty study of the recent caesium biokinetic model quantified the overall uncertainties, and identified the sensitive parameters of the model. A report with guidance on the application of ICRP biokinetic models and dose coefficients is being drafted at present. These and other examples of the group’s activities, which complement the work of ICRP, are presented.

THE ESSENCE, THE NEED FOR EVALUATION AND TYPES OF ECONOMIC POTENTIAL OF ENTERPRISES

2017 ◽  
Author(s):  
Olexandr Yemelyanov ◽  
Keyword(s):  
Economic Activity ◽  
Business Strategies ◽  
Enterprise Management ◽  
Value Assessment ◽  
Economic Potential ◽  
Enterprise Value ◽  
Development Assessment ◽  
State Of The Environment

The formation of business strategies of enterprises should be based on a preliminary assessment of their current and future economic opportunities. Such an assessment is to establish the value of the total economic potential of enterprises and its individual varieties. The purpose of this study was to clarify the essence of the economic potential of enterprises, justify the need for its evaluation and selection of its types. The main approaches to interpreting the terms "potential" and "enterprise potential" are identified. These include resource, result, resource-result, resource-target, and result-target concepts. It is established that the potential of any object, including the enterprise, can be interpreted as a set of its external functional properties, which this object shows or can show in a certain state of the environment in which it is located. Accordingly, the assessment of the potential of an object should be based on the identification and determination of its external properties, taking into account the environment in which the object is located. The main situations in which there is a need for information about certain components of the economic potential of the enterprise are identified, and the types of this potential and the consumers of the information about their level, corresponding to these situations, are determined. In particular, such situations include management of production and sales, management of financial and economic results of the enterprise, management of enterprise development, assessment of the company's need for various types of resources, assessment of enterprise value, assessment of current and future impact of the enterprise on the economy of the country (region), etc. The features of classification of types of enterprise potential existing in the scientific literature are supplemented by the following ones: by the main types of economic activity, by the dynamics of changes in the economic and production system of the enterprise, by consequences for the subject of enterprise potential assessment, by the stages of economic activity, enterprise potential, etc. The obtained results make it possible to improve the understanding of the complex patterns that underlie the formation of the economic potential of enterprises.

State Failure and the Political Violence Phenomenon: A Comparative Analysis of Iraq and Syria Cases

2016 ◽  
Vol 4 (2) ◽  
pp. 170 ◽  
Author(s):  
K. Eylem Özkaya Lassalle
Keyword(s):  
Cold War ◽  
Political Violence ◽  
State Failure ◽  
The Political ◽  
Collective Violence ◽  
Short Run ◽  
Definition Of ◽  
The Cold War

The concept of failed state came to the fore with the end of the Cold War, the collapse of the USSR and the disintegration of Yugoslavia. Political violence is central in these discussions on the definition of the concept or the determination of its dimensions (indicators). Specifically, the level of political violence, the type of political violence and intensity of political violence has been broached in the literature. An effective classification of political violence can lead us to a better understanding of state failure phenomenon. By using Tilly’s classification of collective violence which is based on extent of coordination among violent actors and salience of short-run damage, the role played by political violence in state failure can be understood clearly. In order to do this, two recent cases, Iraq and Syria will be examined.

Method of determination of the text direction on the image with the use of convolutional neural network

2020 ◽  
pp. 96-99
Author(s):  
P.L. Nikolaev
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Deep Neural Network ◽  
Binary Classification ◽  
Synthetic Data ◽  
Real Data ◽  
Method Of Determination ◽  
Classification Of Images

This article deals with method of binary classification of images with small text on them Classification is based on the fact that the text can have 2 directions – it can be positioned horizontally and read from left to right or it can be turned 180 degrees so the image must be rotated to read the sign. This type of text can be found on the covers of a variety of books, so in case of recognizing the covers, it is necessary first to determine the direction of the text before we will directly recognize it. The article suggests the development of a deep neural network for determination of the text position in the context of book covers recognizing. The results of training and testing of a convolutional neural network on synthetic data as well as the examples of the network functioning on the real data are presented.

Actual issues of systematization of scientific knowledge on the conditions of shot in the forensic ballistics

2020 ◽  
Vol 2020 (3) ◽  
pp. 164-169
Author(s):  
Igor' Latyshov ◽  
Fedor Samuylenko
Keyword(s):  
Scientific Knowledge ◽  
Communication Systems ◽  
Production Method ◽  
Natural Phenomenon ◽  
Projectile Energy ◽  
Energy Characteristics ◽  
Shot Classification ◽  
Forensic Ballistics

In this research, there was considered a challenge of constructing a system of scientific knowledge of the shot conditions in judicial ballistics. It was observed that there are underlying factors that are intended to ensureits [scientific knowledge] consistency: identification of the list of shot conditions, which require consideration when solving expert-level research tasks on weapons, cartridges and traces of their action; determination of the communication systems in the course of objects’ interaction, which present the result of exposure to the conditions of the shot; classification of the shot conditions based on the grounds significant for solving scientific and practical problems. The article contains the characteristics of a constructive, functional factor (condition) of weapons and cartridges influence, environmental and fire factors, the structure of the target and its physical properties, situational and spatial factors, and projectile energy characteristics. Highlighted are the forms of connections formed in the course of objects’ interaction, proposed are the author’s classifications of forensically significant shooting conditions with them being divided on the basis of the following criteria: production from the object of interaction, production from a natural phenomenon, production method, results weapon operation and utilization, duration of exposure, type of structural connections between interaction objects, number of conditions that apply when firing and the forming traces.

scholarly journals Internal dose assessment of 148Gd using isotope ratios of gamma-emitting 146Gd or 153Gd in accidently released spallation target particles

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
C. Rääf ◽  
V. Barkauskas ◽  
K. Eriksson Stenström ◽  
C. Bernhardsson ◽  
H. B. L. Pettersson
Keyword(s):  
Operation Time ◽  
Isotope Ratios ◽  
Dose Assessment ◽  
Sensitive Indicator ◽  
Whole Body ◽  
Internal Dose ◽  
Tungsten Target ◽  
Alpha Emitter ◽  
Spallation Source ◽  
Effective Doses

AbstractThe pure alpha emitter 148Gd may have a significant radiological impact in terms of internal dose to exposed humans in case of accidental releases from a spallation source using a tungsten target, such as the one to be used in the European Spallation Source (ESS). In this work we aim to present an approach to indirectly estimate the whole-body burden of 148Gd and the associated committed effective dose in exposed humans, by means of high-resolution gamma spectrometry of the gamma-emitting radiogadolinium isotopes 146Gd and 153Gd that are accompanied by 148Gd generated from the operation of the tungsten target. Theoretical minimum detectable whole-body activity (MDA) and associated internal doses from 148Gd are calculated using a combination of existing biokinetic models and recent computer simulation studies on the generated isotope ratios of 146Gd/148Gd and 153Gd/148Gd in the ESS target. Of the two gamma-emitting gadolinium isotopes, 146Gd is initially the most sensitive indicator of the presence of 148Gd if whole-body counting is performed within a month after the release, using the twin photo peaks of 146Gd centered at 115.4 keV (MDA < 1 Bq for ingested 148Gd, and < 25 Bq for inhaled 148Gd). The corresponding minimum detectable committed effective doses will be less than 1 µSv for ingested 148Gd, but substantially higher for inhaled 148Gd (up to 0.3 mSv), depending on operation time of the target prior to the release. However, a few months after an atmospheric release, 153Gd becomes a much more sensitive indicator of body burdens of 148Gd, with a minimum detectable committed effective doses ranging from 18 to 77 µSv for chronic ingestion and between 0.65 to 2.7 mSv for acute inhalation in connection to the release. The main issue with this indirect method for 148Gd internal dose estimation, is whether the primary photon peaks from 146 and 153Gd can be detected undisturbed. Preliminary simulations show that nuclides such as 182Ta may potentially create perturbations that could impair this evaluation method, and which impact needs to be further studied in future safety assessments of accidental target releases.

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