Doctorat en Sciences de la santé publique / info:eu-repo/semantics/nonPublished

Magister Scientiae Dentium - MSc(Dent) / The level of knowledge and the attitude of dentists regarding radiation safety will have a direct impact on patient exposure to radiation. Aim: The aim of the present study was to evaluate the knowledge and attitude of dentists regarding radiation safety in government dental clinics in Khartoum, Sudan. Materials and Methods: A cross-sectional study using an administered structured questionnaire was carried out. The questionnaire consisted of 13 questions that included the demographic data of dentists, basic knowledge regarding radiation safety, knowledge of methods of dose reduction and the attitude of dentists regarding radiation safety. One hundred and sixty seven dental practitioners participated in the study. Results: The response rate was 90%. The majority were female, 59%, in the age group younger than 29 years with clinical experience less than 10 years. Only fifteen of the respondents identified themselves as specialist. Half of the respondents did not know that the thyroid gland is the most radiosensitive organ in the head and neck region. Forty four percent believed that the dose for panoramic radiography was higher than that for full mouth periapical radiographs. Forty percent had no idea that a relationship exists between the length of the x-ray cone and the amount of the dose and 44% who knew that the relationship existed, failed to explain that the long cone is more effective for reducing the patient dose. Forty seven percent of the respondents had no idea that there is a relationship between the speed of the film and the amount of dose and 44% who knew that the relationship existed, failed to explain that the fast film is more effective for reducing the patient dose. Sixty six percent had no idea that a relationship exists between collimation of the x-ray tube and patient dose. Forty six percent who knew the relationship existed, failed to explain that rectangular collimation is more effective for dose reduction. Seventy two percent of the dentists did not know what a safe distance from the radiation source was. Forty seven percent did not use film holders when taking periapical radiographs. Conclusions: This study clearly illustrates that there is a lack of knowledge regarding radiation safety in dentists in the government dental clinics in Khartoum, Sudan. Therefore there is a need to increase their knowledge regarding methods of radiation dose reduction (to patient) as well as improving their attitude regarding the radiation safety.

The effective dose equivalent, H (or the effective dose, E ) to an individual is the primary limiting quantity in radiation protection. However, techniques for measuring H for neutrons have not been fully developed. In this regard a new tissue equivalent proportional counter (TEPC) based on a gas electron multiplier (GEM) for measuring H*(10), which is a conservative estimate of H, for neutrons was designed and constructed. The deposited energy distribution for two different neutron sources (a Cf-252 source and a AmBe source) was measured using the new TEPC. The measurements were performed using two different proportional gases: P-10 gas and a propane-based tissue equivalent gas at various pressures. A computer simulation of the new TEPC, based on the Monte Carlo method, was performed in order to obtain the pulse height distributions for the two neutron sources. The simulated results and the measured results were compared. Results show that the experimental results agree with the computational results within 20% of accuracy for both Cf-252 and AmBe neutron sources. A new model GEM-based TEPC was developed for use in obtaining H*(10). The value of H*(10) for the Cf-252 source and for the AmBe source using experimental measurements was obtained. These results are presented in this study. The study shows that the GEM-based TEPC can successfully estimate H*(10). With these results and some refinements, this GEM-based TEPC can directly be used as a neutron rem meter.

published_or_final_version / Radioisotope / Master / Master of Philosophy

This thesis reports on the modification of the "Safecode" computer-program to monitor the safety of radio-isotope laboratories, and its application to 24 compliance audits in NSW during the period 1999 to 2006. Additionally, an attempt was made to predict the level of risk to persons working within those laboratories. Based on the current NSW radiation control legislation and the relevant Australian Standards a comprehensive audit checklist was developed for this project. Each safety requirement in those documents was used to develop a question, resulting in 187 questions in the checklist. The questions were grouped into the following seven Topic Elements: Licensing and Registration; Radiation Safety Administration; Personal and Area Monitoring; Dose Limit Compliance; Documentation/Records; RSO/RSC Qualifications and Duties; and Facilities. A novel feature was the allocation of "weighting factors" to individual questions and Elements. The computer program facilitated analysis of data and provided output in spreadsheet and graphical form. .The on-site physical audits were conducted using the project check-list, and were supplemented by discussions with the client's representative. The results showed significant variation between sites with overall compliance scores ranging from 37% to 94%. The reasons for this large variation stem from differences in local management regime; the appointment of an RSO at one site; variation in the extent of adoption of relevant codes of practice; and legislative weaknesses. Further analysis of the data presented legal, advisory and combined scores for each Element for each site; and variations over time. The graphic displays of the results were appreciated by client management. The formula developed to predict risk, based on the physical parameters alone, showed little relationship to the total audit scores. Statistical analysis of the two data groups by correlation coefficient confirmed this general finding. Development of the formula however served to indicate deficiencies in the Question Set, and the importance of human factors in achieving a high degree of safety.

This thesis reports on the modification of the "Safecode" computer-program to monitor the safety of radio-isotope laboratories, and its application to 24 compliance audits in NSW during the period 1999 to 2006. Additionally, an attempt was made to predict the level of risk to persons working within those laboratories. Based on the current NSW radiation control legislation and the relevant Australian Standards a comprehensive audit checklist was developed for this project. Each safety requirement in those documents was used to develop a question, resulting in 187 questions in the checklist. The questions were grouped into the following seven Topic Elements: Licensing and Registration; Radiation Safety Administration; Personal and Area Monitoring; Dose Limit Compliance; Documentation/Records; RSO/RSC Qualifications and Duties; and Facilities. A novel feature was the allocation of "weighting factors" to individual questions and Elements. The computer program facilitated analysis of data and provided output in spreadsheet and graphical form. .The on-site physical audits were conducted using the project check-list, and were supplemented by discussions with the client's representative. The results showed significant variation between sites with overall compliance scores ranging from 37% to 94%. The reasons for this large variation stem from differences in local management regime; the appointment of an RSO at one site; variation in the extent of adoption of relevant codes of practice; and legislative weaknesses. Further analysis of the data presented legal, advisory and combined scores for each Element for each site; and variations over time. The graphic displays of the results were appreciated by client management. The formula developed to predict risk, based on the physical parameters alone, showed little relationship to the total audit scores. Statistical analysis of the two data groups by correlation coefficient confirmed this general finding. Development of the formula however served to indicate deficiencies in the Question Set, and the importance of human factors in achieving a high degree of safety.

A Radiologia tem sido considerada uma das áreas da Medicina que mais se desenvolve, especialmente com o aporte de novas tecnologias. Entre as aplicações da Radiologia Intervencionista destaca-se a utilização da fluoroscopia no centro cirúrgico em complemento às cirurgias ortopédicas, objeto da presente pesquisa. Entretanto, alguns complexos e longos procedimentos guiados fluoroscopicamente podem resultar em altos níveis de exposição ocupacional às radiações ionizantes para equipe de cirurgia ortopédica e trabalhadores de saúde, induzir sérios danos à saúde. Levando em conta esses aspectos, o objetivo geral dessa pesquisa consiste em determinar a exposição ocupacional da equipe de cirurgia ortopédica em procedimentos guiados por fluoroscopia e verificar dentre as cirurgias observadas a que oferece maior exposição ocupacional às radiações ionizantes, como também, a aplicação dos princípios básicos de proteção radiológica nestes procedimentos. A metodologia utilizada para essa pesquisa foi a qualiquantitativa do tipo exploratória. A pesquisa foi realizada no Hospital de Clínicas da Universidade Federal de Curitiba (UFPR). Os sujeitos pesquisados foram os membros da equipe de cirurgia ortopédica, ou seja, médicos ortopedistas, residentes, anestesias, instrumentador cirúrgico, técnicos e auxiliares de enfermagem, e enfermeiros. A coleta de dados foi realizada de 01 de janeiro a 30 de maio de 2011. Contribuíram para a pesquisa, 44 trabalhadores que responderam uma entrevista coletiva, e um questionário com 25 perguntas fechadas. foi constituídos quatro grupos de onze participantes cada, seguida de análise documental e de monitoração da área pesquisada e individual. Os resultados mostraram que os profissionais de saúde do setor pesquisado expõem-se às radiações ionizantes, devido à demanda de cirurgias guiadas por equipamentos emissores de radiação ionizantes fluoroscopicamente, e a falta de conhecimento em radioproteção. Diante dessas constatações foram sugeridas pelos grupos medidas de prevenção a essas exposições de modo a minimizar possíveis efeitos biológicos das radiações ionizantes. Foi concluído que existe exposição ocupacional com os trabalhadores do setor pesquisado, os mesmos tem pouco conhecimento quanto ao uso dos equipamentos de radioproteção nos procedimentos cirúrgicos com equipamentos emissores de radiações ionizantes, não usam corretamente os monitores individuais. / Radiology has been considered one of the areas of medicine that most devel-ops, especially with the contribution of new technologies. Among the applications of Interventional Radiology highlights the use of fluoroscopy in the surgical center in addition to co-orthopedic surgeries, the object of the present research. Entretan-to some complex and lengthy fluoroscopically guided procedures can result in high levels of occupational exposure to ionizing radiation for e-quipe orthopedic surgery and health workers, induce serious damage to health. Considering these aspects, the general objective of this research is to de-termine the occupational exposure of the team of orthopedic surgery proce-dures guided by fluoroscopy and verify observed among the surgeries that offer greater occupational exposure to ionizing radiation, but also the application of basic principles of radiological protection in these procedures. The methodology for this research was the qualitative and quantitative exploratory type. The research was conducted at Hospital de Clinicas, Federal University of Curitiba (UFPR). Study subjects were members of the team of orthopedic surgery, or orthopedic doctors, residents, anesthesia, surgical instrumentator, technicians and nursing assistants, and nurses. Data collection was performed from January 1 to May 30, 2011. Contributors to the survey, 44 workers who answered a news conference, and a questionnaire with 25 closed questions of. was divided in four groups of eleven participants each, followed by document analysis and monitoring of the area and searched individually. The results we-strated that the health sector professionals surveyed were exposed to ionizing radiation, due to demand-driven surgery equipment emitting ionizing radiation fluoroscopically, and the lack of knowledge in radioprote-tion. Before these findings were suggested by the groups pre-vention measures of these exposures to minimize possible biological effects of ionizing radiation-tions. It was concluded that occupational exposure exists with re-worked in the sector researched, they have little knowledge about the use of radiation protection equipment in surgical procedures with equipment emitting ionizing radiation, properly use the monitors indi-tions.

Esse estudo tem por objetivo geral propor um mapa espacial de doses como ferramenta auxiliar na avaliação da necessidade de otimização de ambientes em serviços de medicina nuclear e, por objetivos específicos, avaliar as dosimetrias individuais dos trabalhadores; analisar a estrutura física dos serviços de medicina nuclear; avaliar as taxas de dose do ambiente. A pesquisa realizada se caracteriza como um estudo de caso, de natureza exploratória e explicativa, em três Serviços de Medicina Nuclear estabelecidos na região Noroeste do Estado do Paraná. Os resultados obtidos indicaram que as taxas de dose avaliadas e a dosimetria dos trabalhadores, em todas as dependências dos serviços pesquisados, respeitam os limites de doses anuais, mas algumas excedem os limites de investigações preconizados na norma NN-CNEN 3.01 (2014). Concluiu-se que o mapa espacial de dose é uma ferramenta importante para os serviços de medicina nuclear, pois facilita a visualização das áreas com maior concentração de radiação, bem como a revisão contínua de tais medidas e recursos para identificar quaisquer falhas e deficiências na sua aplicação, corrigi-las e evitar suas repetições, além de verificar regularmente se os objetivos de proteção radiológica estão sendo alcançados. / This study has as general aim to propose a spatial map of doses as an auxiliary tool in assessing the need for optimization of the workplace in nuclear medicine services. As specific aims, we assessed the workers individual dosimetry; we analyzed the facilities of the nuclear medicine services; and we evaluated environment exposure rates. The research is characterized as a case study, with an exploratory and explanatory nature. It was conducted in three Nuclear Medicine Services, all established in the Northwest of the Paraná State. Results indicated that the evaluated dose rates and workers dosimetry, in all the dependencies of the surveyed services, are within the limits of annual doses. However some exceeded the limits recommended in the standard CNEN-NN 3:01 (2014). It was concluded that the spatial map dose is an important tool for nuclear medicine services because it facilitates the visualization of areas with highest concentration of radiation, and also helps in the constant review of these measures and resources, aiding in the identification of any failures and shortcomings, providing resources to correct any issues and prevent their repetition. The spatial map dose is also important for the regular inspection, evaluating if the radiation protection objectives are being met.

A Radiologia tem sido considerada uma das áreas da Medicina que mais se desenvolve, especialmente com o aporte de novas tecnologias. Entre as aplicações da Radiologia Intervencionista destaca-se a utilização da fluoroscopia no centro cirúrgico em complemento às cirurgias ortopédicas, objeto da presente pesquisa. Entretanto, alguns complexos e longos procedimentos guiados fluoroscopicamente podem resultar em altos níveis de exposição ocupacional às radiações ionizantes para equipe de cirurgia ortopédica e trabalhadores de saúde, induzir sérios danos à saúde. Levando em conta esses aspectos, o objetivo geral dessa pesquisa consiste em determinar a exposição ocupacional da equipe de cirurgia ortopédica em procedimentos guiados por fluoroscopia e verificar dentre as cirurgias observadas a que oferece maior exposição ocupacional às radiações ionizantes, como também, a aplicação dos princípios básicos de proteção radiológica nestes procedimentos. A metodologia utilizada para essa pesquisa foi a qualiquantitativa do tipo exploratória. A pesquisa foi realizada no Hospital de Clínicas da Universidade Federal de Curitiba (UFPR). Os sujeitos pesquisados foram os membros da equipe de cirurgia ortopédica, ou seja, médicos ortopedistas, residentes, anestesias, instrumentador cirúrgico, técnicos e auxiliares de enfermagem, e enfermeiros. A coleta de dados foi realizada de 01 de janeiro a 30 de maio de 2011. Contribuíram para a pesquisa, 44 trabalhadores que responderam uma entrevista coletiva, e um questionário com 25 perguntas fechadas. foi constituídos quatro grupos de onze participantes cada, seguida de análise documental e de monitoração da área pesquisada e individual. Os resultados mostraram que os profissionais de saúde do setor pesquisado expõem-se às radiações ionizantes, devido à demanda de cirurgias guiadas por equipamentos emissores de radiação ionizantes fluoroscopicamente, e a falta de conhecimento em radioproteção. Diante dessas constatações foram sugeridas pelos grupos medidas de prevenção a essas exposições de modo a minimizar possíveis efeitos biológicos das radiações ionizantes. Foi concluído que existe exposição ocupacional com os trabalhadores do setor pesquisado, os mesmos tem pouco conhecimento quanto ao uso dos equipamentos de radioproteção nos procedimentos cirúrgicos com equipamentos emissores de radiações ionizantes, não usam corretamente os monitores individuais. / Radiology has been considered one of the areas of medicine that most devel-ops, especially with the contribution of new technologies. Among the applications of Interventional Radiology highlights the use of fluoroscopy in the surgical center in addition to co-orthopedic surgeries, the object of the present research. Entretan-to some complex and lengthy fluoroscopically guided procedures can result in high levels of occupational exposure to ionizing radiation for e-quipe orthopedic surgery and health workers, induce serious damage to health. Considering these aspects, the general objective of this research is to de-termine the occupational exposure of the team of orthopedic surgery proce-dures guided by fluoroscopy and verify observed among the surgeries that offer greater occupational exposure to ionizing radiation, but also the application of basic principles of radiological protection in these procedures. The methodology for this research was the qualitative and quantitative exploratory type. The research was conducted at Hospital de Clinicas, Federal University of Curitiba (UFPR). Study subjects were members of the team of orthopedic surgery, or orthopedic doctors, residents, anesthesia, surgical instrumentator, technicians and nursing assistants, and nurses. Data collection was performed from January 1 to May 30, 2011. Contributors to the survey, 44 workers who answered a news conference, and a questionnaire with 25 closed questions of. was divided in four groups of eleven participants each, followed by document analysis and monitoring of the area and searched individually. The results we-strated that the health sector professionals surveyed were exposed to ionizing radiation, due to demand-driven surgery equipment emitting ionizing radiation fluoroscopically, and the lack of knowledge in radioprote-tion. Before these findings were suggested by the groups pre-vention measures of these exposures to minimize possible biological effects of ionizing radiation-tions. It was concluded that occupational exposure exists with re-worked in the sector researched, they have little knowledge about the use of radiation protection equipment in surgical procedures with equipment emitting ionizing radiation, properly use the monitors indi-tions.

Esse estudo tem por objetivo geral propor um mapa espacial de doses como ferramenta auxiliar na avaliação da necessidade de otimização de ambientes em serviços de medicina nuclear e, por objetivos específicos, avaliar as dosimetrias individuais dos trabalhadores; analisar a estrutura física dos serviços de medicina nuclear; avaliar as taxas de dose do ambiente. A pesquisa realizada se caracteriza como um estudo de caso, de natureza exploratória e explicativa, em três Serviços de Medicina Nuclear estabelecidos na região Noroeste do Estado do Paraná. Os resultados obtidos indicaram que as taxas de dose avaliadas e a dosimetria dos trabalhadores, em todas as dependências dos serviços pesquisados, respeitam os limites de doses anuais, mas algumas excedem os limites de investigações preconizados na norma NN-CNEN 3.01 (2014). Concluiu-se que o mapa espacial de dose é uma ferramenta importante para os serviços de medicina nuclear, pois facilita a visualização das áreas com maior concentração de radiação, bem como a revisão contínua de tais medidas e recursos para identificar quaisquer falhas e deficiências na sua aplicação, corrigi-las e evitar suas repetições, além de verificar regularmente se os objetivos de proteção radiológica estão sendo alcançados. / This study has as general aim to propose a spatial map of doses as an auxiliary tool in assessing the need for optimization of the workplace in nuclear medicine services. As specific aims, we assessed the workers individual dosimetry; we analyzed the facilities of the nuclear medicine services; and we evaluated environment exposure rates. The research is characterized as a case study, with an exploratory and explanatory nature. It was conducted in three Nuclear Medicine Services, all established in the Northwest of the Paraná State. Results indicated that the evaluated dose rates and workers dosimetry, in all the dependencies of the surveyed services, are within the limits of annual doses. However some exceeded the limits recommended in the standard CNEN-NN 3:01 (2014). It was concluded that the spatial map dose is an important tool for nuclear medicine services because it facilitates the visualization of areas with highest concentration of radiation, and also helps in the constant review of these measures and resources, aiding in the identification of any failures and shortcomings, providing resources to correct any issues and prevent their repetition. The spatial map dose is also important for the regular inspection, evaluating if the radiation protection objectives are being met.