A dose resultante da contaminação interna pode ser estimada por meio de modelos biocinéticos em conjunto com os resultados experimentais obtidos de medidas de bioanálise e do conhecimento do momento da incorporação. Os modelos biocinéticos são representados por um conjunto de compartimentos que expressam o transporte, a retenção e a eliminação dos radionuclídeos do organismo. As publicações 66, 78 e 100 da ICRP apresentam modelos compartimentais para o trato respiratório, trato gastrointestinal e de distribuição sistêmica para diversos radionuclídeos de interesse para a proteção radiológica. O objetivo deste trabalho é desenvolver um código computacional para utilização em Dosimetria Interna considerando os principais radionuclídeos de interesse do IPEN do ponto de vista das exposições ocupacionais, tanto em situações rotineiras como também em casos acidentais, de modo a servir de ferramenta ágil e eficiente na construção, visualização e resolução de modelos compartimentais de qualquer natureza. A arquitetura do sistema foi concebida contendo dois programas independentes: CBT - responsável pela criação e manipulação dos modelos, e SSID - responsável pela resolução matemática dos mesmos. São oferecidas quatro técnicas diferentes para a resolução do sistema de equações incluindo métodos semi-analíticos e numéricos, onde se pode comparar a precisão e o desempenho destas. O desenvolvimento foi feito na linguagem de programação C#, utilizando um banco de dados Microsoft Access e o padrão XML para a troca de arquivos com outros aplicativos. Para a validação do programa CBT foram construídos os modelos de compartimentos para os radionuclídeos urânio, tório e iodo. Com o programa SSID os modelos foram resolvidos e os resultados comparados com os valores publicados pela ICRP 78. Em todos os casos, o sistema desenvolvido conseguiu reproduzir os valores publicados pela ICRP. / The dose resulting from internal contamination can be estimated with the use of biokinetic models combined with experimental results obtained from bioanalysis and assessment of the time of incorporation. The biokinetics models are represented by a set of compartments expressing the transportation, retention and elimination of radionuclides from the body. The ICRP publications, number 66, 78 and 100, present compartmental models for the respiratory tract, gastrointestinal tract and for systemic distribution for an array of radionuclides of interest for the radiological protection. The objective of this work is to develop a computational code for the internal doses assessment of the main radionuclides of occupational exposure at IPEN. Consequently serving as a agile and efficient tool for the designing, visualization and resolution of compartmental models of any nature. The architecture of the system was conceived containing two independent software: CBT responsible for the setup and manipulation of models and SSID responsible for the mathematical solution of the models. Four different techniques are offered for the resolution of system of equations, including semi-analytical and numerical methods, allowing for comparison of precision and performance of both. The software was developed in C# programming, using a Microsoft Access database and XML standards for file exchange with other applications. Compartmental models for uranium, thorium and iodine radionuclides were generated for the validation of the CBT software. The models were subsequently solved via SSID software and the results compared with the values published in the issue 78 of ICRP. In all cases the system replicated the values published by ICRP.

Este estudo foi desenvolvido no Instituto de Pesquisas Energéticas e Nucleares - IPEN mais especificamente, no Centro de Radiofarmácia - CR que realiza pesquisa e processamento de radiosótopos como o 99Mo, 131I, 123I, 67Ga, 201Tl, 18F, 177Lu e 153Sm para uso em medicina nuclear. Os radioisótopos são produzidos em escala industrial e a instalação foi projetada para atender aos padrões de segurança radiológica e às exigências da Garantia de qualidade. No CR há profissionais qualificados que realizam as tarefas de manutenção dos equipamentos e instrumentos, instalados nas celas de processamento de radiofármacos, sem os quais não é possível conduzir a produção com segurança e qualidade. Neste estudo foi realizada uma pesquisa denominada Pesquisa de Variáveis, baseada nas operações de manutenções e intervenções em áreas restritas do CR e no levantamento da distribuição de doses nessas tarefas no período de 2005 a 2011. Esta pesquisa tem por objetivo identificar e determinar as principais variáveis que tem impacto sobre a dose do trabalhador. Os resultados obtidos foram apresentados para variável Indivíduo Ocupacionalmente Exposto - IOE, variável Operação, variável Área/Cela, variável Tipo de Tarefa e variável Duração de Operação, em função da variável Dose. O objetivo deste trabalho foi contribuir com melhorias nas operações em áreas restritas que possam resultar em doses individuais mais baixas sem causar alterações significativas na rotina de trabalho. A análise dos resultados mostrou que a Pesquisa a Variáveis identificou os fatores que mais impactam com a dose recebida. São eles variável Operação, variável Área/Cela e variável Tipo de Tarefa. / This study was developed at IPEN - Institute of Energy and Nuclear Research more specifically in CR - Center of Radiopharmacy that conducts research and processing of radiopharmaceuticals such as 99Mo, 131I, 123I, 67Ga, 201Tl, 18F, 177Lu and 153Sm for use in nuclear medicine. The radioisotopes are produced on industrial scale and the facility was designed to meet the standards of radiation safety requirements and quality control. To ensure the production, there are qualified professionals who perform the maintenance tasks of the equipments and instruments, in the radiopharmaceuticals processing cells, to conduct the work with quality and safety. This study were based in a research called \"Search of Variables\", for the operations carried out in restricted areas of CR, taking into account the doses distribution data for these tasks, from 2005 to 2011. This research aims to identify and determine the key variables that impact on the worker\'s dose. The results were presented for the following variables: Individual occupationally exposed - IOE, operation variable, Area/Cell, Type of Task and Duration of Operation, which depend on the variable Dose. The main objective is to contribute to the improvements in operations in restricted areas that may result in lower individual doses without causing significant changes in the working routine. The results have shown the variable that most affect the dose of the workers, which are: the variable Operation, the variable Area/Cell and the variable Type of Task.

Bakgrund: Utvecklingen av genomlysnings-baserade interventioner har varit framgångsrika de senaste årtiondena, då det gäller behandling av patienter. Införandet av genomlysning har dock medfört risker, för både patient och personal. Detta på grund av att stråldoser ökat i takt med en större efterfrågan på genomlysning och en utveckling av mer avancerade undersökningar. Med tanke på att stråldosen från intervention har en biologisk långtidseffekt, så är strålskydd ett upp-märksammat och återkommande ämne då det påverkar både sjukvårdspersonal, patienter och sam-hället. Brist på strålskydd och oaktsamhet hos operatörerna medför en ökad risk för strålningsindu-cerade skador. Eftersom antalet interventioner ständigt ökar så behövs även en ökad medvetenhet hos vårdpersonal kring vilka risker strålningen kan medföra och hur de kan undvikas. Syfte: Att beskriva vilka åtgärder som kan vidtas för att minska stråldosen för personal och patient vid angiografi/intervention. Metod: En systematisk litteraturstudie har använts. Resultat: I det sammanställda resultatet har flera olika strålskyddsåtgärder presenterats för att reducera stråldosen under intervention/angiografi. Genomlysningstid, modern teknik, uppdaterade inställningar i apparaturen och blyskydd har alla visat sig minska stråldosen markant till patient och personal. Utbildning och feedback ses även vara en viktig del i strålskyddsarbetet då det utgör grun-den för att riktlinjer kring strålskydd följs. Slutsats: Att det finns alternativa strålskyddsåtgärder vid IR- undersökningar/åtgärder är något som kan konstateras. Faktum är att en kombination av dessa åtgärder helt klart vore optimalt, för ökad säkerhet hos både personal och patienter vid exponering av strålning. / Background: The development of fluoroscopy-guided interventions the recent decades has resulted in a successful treatment of patients. However, the introduction of these diagnostic devices carry risks for both patients and staff. This is due to the fact that radiation doses increases in line with a greater demand for interventions and the development of advanced procedures. The radiation may cause long-term biological effects which makes radiation protection an important subject as it affects both staff, patients and society. Lack of radiation protection and negligence among operators cause an increased risk of radiation-induced damage. As the number of interventions constantly increase, improved knowledge is needed. Aim: The aim of this study is to describe which methods can be applied in order to reduce radiation doses for staff and patients in angiography / intervention. Method: A systematic study of existing literature. Results: The result shows several different radiation protection strategies to reduce the radiation dose during intervention / angiography. Fluoroscopy time, modern technology, updated settings in the device and lead protection have all been shown to reduce radiation dose significantly to both patients and staff. Education and feedback are also considered to be an important part of the radiation safety as they provide the basic guidelines on radiation protection. Conclusion: There is a lot of alternative radiation protection strategies in fluoroscopy-guided inter-ventions. In fact, a combination of these strategies would clearly be optimal for increased safety for both staff and patients exposed to radiation.

<p>Radiation quality is described by the RBE (relative biological effectiveness) that varies with the ionizing ability of the radiation. Microdosimetric quantities describe distributions of energy imparted to small volumes and can be related to RBE. This has made microdosimetry a powerful tool for radiation quality determinations in both radiation protection and radiation therapy. The variance-covariance method determines the dose-average of the distributions and has traditionally been used with two detectors to correct for beam intensity variations. Methods to separate dose components in mixed radiation fields and to correct for beam variations using only one detector have been developed in this thesis. Quality factor relations have been optimized for different neutron energies, and a new algorithm that takes single energy deposition events from densely ionizing radiation into account has been formulated. The variance-covariance technique and the new methodology have been shown to work well in the cosmic radiation field onboard aircraft, in the mixed photon and neutron fields in the nuclear industry and in pulsed fields around accelerators.</p><p>The method has also been used for radiation quality characterization in therapy beams. The biological damage is related to track-structure and ionization clusters and requires descriptions of the energy depositions in nanometre sized volumes. It was shown that both measurements and Monte Carlo simulation (condensed history and track-structure) are needed for a reliable nanodosimetric beam characterization. The combined experimental and simulated results indicate that the dose-mean of the energy imparted to an object in the nanometre region is related to the clinical RBE in neutron, proton and photon beams. The results suggest that the variance-covariance technique and the dose-average of the microdosimetric quantities could be well suited for describing radiation quality also in therapy beams.</p>

<p>At the University Hospital of Umeå, NUS, a new radiation treatment department is being built. The purpose of this master thesis is to evaluate the actual radiation protection outside three out of five treatment rooms in the building, including two Varian and one Siemens accelerator, and to verify that the radiation limits for the staff and the general public, stated by the Swedish Radiation Safety Authority, are obeyed.</p><p>The evaluation of the radiation protection shielding is made through measurements. The nominal photon beam energies 6 and 15 MV (dose rates up to 500 MU/min) can be used, which means that both photons and neutrons will contribute to the effective dose. For the photon measurements, two different GM counters have been used and for the neutron measurements a Neutron detector with a polyethylene moderator and a ³He recoil proton counter tube was applied. The thesis also includes a literature study of the photon and neutron energy spectra outside the treatment rooms in order to check that the measurement equipments are suitable to use.</p><p>The measured doses of the radiation shielding are below the radiation limits per week and year but the measurements indicate too high values per hour, i.e. momentary dose rate, at the height of isocenter of the primary walls and at the gap under the door for all three accelerators. The rooms with the Varian accelerators also show too high values per hour at the secondary wall where the door is attached. However, the limiting value per hour is only a recommendation and no extra reinforcement in therefore required. Nevertheless, one should avoid placing a workplace, for example a writing desk, close to the secondary and primary walls.</p>

Radiation quality is described by the RBE (relative biological effectiveness) that varies with the ionizing ability of the radiation. Microdosimetric quantities describe distributions of energy imparted to small volumes and can be related to RBE. This has made microdosimetry a powerful tool for radiation quality determinations in both radiation protection and radiation therapy. The variance-covariance method determines the dose-average of the distributions and has traditionally been used with two detectors to correct for beam intensity variations. Methods to separate dose components in mixed radiation fields and to correct for beam variations using only one detector have been developed in this thesis. Quality factor relations have been optimized for different neutron energies, and a new algorithm that takes single energy deposition events from densely ionizing radiation into account has been formulated. The variance-covariance technique and the new methodology have been shown to work well in the cosmic radiation field onboard aircraft, in the mixed photon and neutron fields in the nuclear industry and in pulsed fields around accelerators. The method has also been used for radiation quality characterization in therapy beams. The biological damage is related to track-structure and ionization clusters and requires descriptions of the energy depositions in nanometre sized volumes. It was shown that both measurements and Monte Carlo simulation (condensed history and track-structure) are needed for a reliable nanodosimetric beam characterization. The combined experimental and simulated results indicate that the dose-mean of the energy imparted to an object in the nanometre region is related to the clinical RBE in neutron, proton and photon beams. The results suggest that the variance-covariance technique and the dose-average of the microdosimetric quantities could be well suited for describing radiation quality also in therapy beams.

At the University Hospital of Umeå, NUS, a new radiation treatment department is being built. The purpose of this master thesis is to evaluate the actual radiation protection outside three out of five treatment rooms in the building, including two Varian and one Siemens accelerator, and to verify that the radiation limits for the staff and the general public, stated by the Swedish Radiation Safety Authority, are obeyed. The evaluation of the radiation protection shielding is made through measurements. The nominal photon beam energies 6 and 15 MV (dose rates up to 500 MU/min) can be used, which means that both photons and neutrons will contribute to the effective dose. For the photon measurements, two different GM counters have been used and for the neutron measurements a Neutron detector with a polyethylene moderator and a 3He recoil proton counter tube was applied. The thesis also includes a literature study of the photon and neutron energy spectra outside the treatment rooms in order to check that the measurement equipments are suitable to use. The measured doses of the radiation shielding are below the radiation limits per week and year but the measurements indicate too high values per hour, i.e. momentary dose rate, at the height of isocenter of the primary walls and at the gap under the door for all three accelerators. The rooms with the Varian accelerators also show too high values per hour at the secondary wall where the door is attached. However, the limiting value per hour is only a recommendation and no extra reinforcement in therefore required. Nevertheless, one should avoid placing a workplace, for example a writing desk, close to the secondary and primary walls.

The main objective of this research is: (1) to develop a model and perform numerical simulations to evaluate the radiation field and the resulting dose to personnel and activation of materials and structures throughout the IRIS nuclear power plant, and (2) to confirm that the doses are below the regulatory limit, and assess the possibility to reduce the activation of the concrete walls around the reactor vessel to below the free release limit. IRIS is a new integral pressurized water reactor (PWR) developed by an international team led by Westinghouse with an electrical generation capacity of 335 MWe and passive safety systems. Its design differs from larger loop PWRs in that a single building houses the containment as well as all the associated equipment including the control room that must be staffed continuously. The resulting small footprint has positive safety and economic implications, and the integral layout provides additional shielding and thus the opportunity to significantly reduce the activation, but it also leads to significantly more challenging simulations. The difficulty in modeling the entire building is the fact that the source is attenuated over 10 orders of magnitude before ever reaching the accessible areas. For an analog Monte Carlo simulation with no acceleration (variance reduction), it would take many processor-years of computation to generate results that are statistically meaningful. Instead, to generate results for this thesis, the Standardized Computer Analyses for Licensing Evaluation (SCALE) with the package Monaco with Automated Variance Reduction using Importance Calculations (MAVRIC) will be used. This package is a hybrid methodology code where the forward and adjoint deterministic calculations provide variance reduction parameters for the Monte Carlo portion to significantly reduce the computational time. Thus, the first task will be to develop an efficient SCALE/MAVRIC model of the IRIS building. The second task will be to evaluate the dose rate and activation of materials, specifically focusing on activation of concrete walls around the reactor vessel. Finally, results and recommendations will be presented.

Beam dumps are installed at the experimental areas of the ELBE facility. Their purpose is to absorb the primary electron beam and the secondary radiation. The beam dump consists of a purified graphite core inside a water cooled stainless steel vessel. The radiation shield surrounding the beam dump will be designed individually for each experimental area. In this context, dose rate calculations were carried out to estimate the dose rate source term around the stainless steel vessel of the beam dump. Detailed Monte Carlo simulations were carried out using the code FLUKA. The energy dependent photon and neutron fluences and the equivalent dose rates were obtained near the surface of the cylindrical steel vessel for a beam current of 1 mA and energies of 20 MeV and 50 MeV.

Το Διαδίκτυο, γνωστό συνήθως και με την αγγλική άκλιτη ονομασία Internet, ανήκει στα μέσα μαζικής επικοινωνίας (ΜΜΕ). Ως μέσο έχει διπλή υπόσταση: υλική (που αποτελείται από τον συνδυασμό δικτύων βασισμένων σε λογισμικό και υλικό), και άϋλη (αυτό, δηλαδή, που "κάνει" / προσφέρει στην κοινωνία το Διαδίκτυο ως μέσο). Ο σκοπός αυτής της μελέτης είναι να παρουσιαστούν τα κριτήρια με τα οποία μπορεί ν’ αξιολογηθεί η ποιότητα μιας ιστοσελίδας με περιεχόμενα Κλινικής Ακτινοπροστασίας και Γενικής Ιατρικής και ο σχεδιασμός ενός πρότυπου ιστοτόπου που να παρέχει ακτινολογικές πληροφορίες στον Γενικό Ιατρό, έχοντας σαν βάση τον ιστότοπο της Εταιρείας Γενικής Ιατρικής. Το υλικό της ερευνητικής μελέτης αποτέλεσαν πέντε (5) ιστότοποι που είναι σχετικοί με περιεχόμενο Γενικής Ιατρικής και κλινικής Ακτινοπροστασίας. Επελέγησαν με βάση την επισκεψιμότητά τους. Αξιολογήθηκαν με βάση πρώτον τα κριτήρια της ποιότητας ενός site σχετιζόμενο με ιατρικό περιεχόμενο, δεύτερον με τα τεχνικά κριτήρια και τρίτον με τα κριτήρια ποιότητας ενός ιστοτόπου από το Ίδρυμα Health on Net Fountation (HON). Επίσης αξιολογήθηκαν με βάση την επισκεψιμότητά τους παγκοσμίως – αλλά και στη χώρα τους. Παράλληλα παρατηρήθηκε η δημοτικότητά τους από τον αριθμό των sites που τα έχουν ως link. Επιπλέον καταμετρήθηκε το upstream link των υπό παρακολούθηση ιστοτόπων με κάποιες από τις παγκόσμιες μηχανές αναζήτησης. Αξιολογήθηκε επίσης το επίσημο site της Ελληνικής Εταιρείας Γενικής Ιατρικής (ΕΛΕΓΕΙΑ) για στοιχεία κλινικής ακτινοπροστασίας. Μόνο 4 ιστότοποι πληρούσαν τα 18 από τα 19 κριτήρια. Και τα 5 sites πληρούσαν τα τεχνικά κριτήρια και τα κριτήρια του HON. Βάση επισκεψιμότητάς και δημοτικότητάς τους, πρώτο βρέθηκε το site της Αμερικάνικης Εταιρείας Προστασίας του Περιβάλλοντος, με δεύτερο της Αμερικανικής Ακαδημίας των Οικογενειακών Ιατρών. Το site της ΕΛΕΓΕΙΑ δεν παρείχε καμία πληροφορία ακτινολογικού περιεχομένου. Παρατηρείται θετικότατη εφαρμογή στα τεχνικά κριτήρια αξιολόγησης και ποιότητας καθώς και στα κριτήρια του HON. Μεγάλη είναι και η επισκεψιμότητα και η δημοτικότητα των υπό αξιολόγηση sites. Εύκολη και χρηστική η λειτουργικότητα τους με άμεση παρουσίαση στοιχείων – απαντήσεων. Οι προτάσεις για δημιουργία πρότυπου ιστοτόπου βασιζόμενες στο site της ΕΛΕΓΕΙΑΣ (αφού δεν παρείχε καμία πληροφορία) είναι η συνεργασία με τους Ακτινολόγους (Ελληνικής Εταιρείας Ακτινολογίας) για την συγγραφή θεμάτων κοινού ενδιαφέροντος. Παρουσίαση του συνόλου των ακτινολογικών εξετάσεων για κάθε πιθανό παθολογικό – χειρουργικό θέμα. Παράλληλα αναφορά στην σωστή χρήση των σκιαγραφικών, στην σωστή συνταγογράφησή τους, στην σωστή προετοιμασία (αν χρειαζόταν και πότε) του ασθενούς, σε πιθανά προβλήματα από την χρήση των σκιαγραφικών (π.χ. αλλεργία), στις εν δυνάμει παρενέργειες στον ασθενή και στο περιβάλλον του κλπ. Η ανακοίνωση νέων τεχνολογιών και μεθόδων απεικόνισης. Δημιουργία e-learning (συνεχιζόμενη ιατρική εκπαίδευση) για ειδικευόμενους και ειδικευμένους Γενικούς Ιατρούς. Επίσης δημιουργία link με παροχή πληροφοριών με θεωρία και εικόνες, ημερομηνία τελευταίας ενημέρωσης, δημιουργία μηχανής αναζήτησης, χωρίς log in, καταμέτρηση επισκεπτών του link ημερησίως και ετήσια. Ένα τέτοιο link θα βελτίωνε την καθημέρα πράξη των Γενικών / Οικογενειακών Ιατρών. / The Internet, commonly known with the English name Internet, belongs to the media. As an instrument has a dual personality: the material (which consists of a combination of network-based software and hardware) and intangible (that is, to "do" / offers society the Internet as a medium). The purpose of this study is to present the criteria which can be evaluated by the quality of a website with content clinical radiation protection and General Medicine and design a standard website. The research material consisted of five (5) sites that are relevant to content clinical radiation protection and General Medicine. Selected based on their trafficing. Evaluated on the basis of firstly quality criteria for a site related to medical content, secondly the technical criteria and thirdly, the quality criteria of the website of the Health on Net Fountation (HON). Also evaluated based on their traffic worldwide - and at home. Occurred while the popularity of the number of sites who have them as a link. Moreover surveyed upstream link of the monitored sites with some of the world's search engines. Also evaluated the official site of the Greek Society of General Medicine (ELEGEIA) for clinical radiation protection. Only 4 (out of 18 met the 19 criteria) from 5 sites did not meet in full the 19 quality criteria. And 5 sites met the technical criteria and criteria of HON. Base traffic and popularity, first found the site of the American Association for protection of the environment in second the American Academy of Family Physicians. The site's ELEGEIA provided no information radiological nature. There is a very positive implementation of the technical evaluation criteria and quality criteria and the HON’s criteria. Great is the traffic and the popularity of the evaluated sites. Simple and utilitarian functionality with immediate display of data - responses. Proposals to create a standard site in the site of ELEGEIA (having provided no information) is a collaboration with radiologists (Greek Society of Radiology) for writing topics of common interest. Presentation of all radiological examinations every possible pathological - surgical issue. Also reference to the proper use of contrast substances, the right prescription, the proper preparation (if needed and when) the patient to possible problems with the use of contrast substances (eg allergy), the potential side effects to the patient and the environment etc. The announcement of new imaging technologies and methods. Create e-learning (continuing medical education) for junior and qualified general practitioners. Also creation a link with information theory and images, date of last update, creation of a search engine, free log in, counting visitors to link daily and annual. Such a link would improve the daily lives of General practice / Family Physicians.