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Development of system reduction and limitation of doses in persons working with sources of ionizing radiation and in inhabitants
TEPLÝ, Antonín
Development of system reduction and limitation of doses in persons working with sources of ionizing radiation and in inhabitants This dissertation discusses a system of limits and its development, i.e. how did the radiation dose limits change due to the safety of staff working with ionizing radiation and how did the limits of exposure of the population change. The introduction part of this dissertation deals with basic principles of radiation protection, namely with its optimization {--} with ALARA system. In the Current situation chapter there is a system of limits for reduction of radiation (Sec. 18 and 22 of the State Office for Nuclear Safety Decree No 307/2002 Sb.) and derived limits. The main part of this project focuses on monitoring of the practical development of the system of limits. In the Radiation Oncology Institute of the Faculty Hospital Na Bulovce (Ústav radiační onkologie Fakultní nemocnice Na Bulovce) archive I received data from the CSOD. I processed listing of both free-month and one-month doses received by the staff and I studied the way the doses decrease and mainly how does the number of personnel in whose cases the doses exceeded their limits decrease. I involved three most numerous groups of personnel. The first group consists of radiology assistants and analysts, the second group consists of medical doctors and physicists and the third group consists of medical nurses who were monitored only till 2003. The greatest decrease can be noticed since 2003 when the listings of radiation doses started being evaluated on monthly basis. I think that monthly evaluation of doses is a great landmark in the issue of protection of personnel involved with ionizing radiation. I transferred the data about these doses into several charts. I divided exceeded doses into individual scales and processed them statistically. There is a table in the discussion part of this dissertation work where even historical dose limits and dose equivalents are converted to mSv units (i.e. mSv/year) so that it would be possible to compare the limits. The process of radiation protection of the personnel in the Institute is also dealt with.
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Dose Measurement at a Radiotherapy Workplace by Means of Personal Dosimeters
ČERNOHORSKÁ, Adéla
Abstract Dose Measurement at a Radiotherapy Workplace by Means of Personal Dosimeters Ionising radiation may have negative influence on human organism, which is why protection against it is so important. Limits for radiotherapy workplaces, where medical staff work every day close to a source of the radiation, are defined by Decree No. 184/1997 Col. Personal monitoring is used at workplaces with ionizing radiation sources to measure monthly doses, which should not exceed particular limits. Personal dosimeters, apparatuses capable of detecting ionizing radiation are used for personnel monitoring. There are various types of dosimeters available, based on different principles. So called film dosimeters are used at the radiotherapy department of the Hospital České Budějovice. These dosimeters are sent to the National Personal Dosimetry Service every month where they are assessed. The aim of my work was to find out whether radiotherapy department staff and some places there may also be measured by DMC 2000 XB dosimeters by Merlin Gerin, to measure these activities and places and to compare the results with those detected by the film tape and TL type dosimeters.
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Ionizing radiation doses of the radiology assistants in the CT and PET/CT wards
MAZLOVÁ, Lenka
Hybrid methods, such as PET/CT, operating with the ionizing radiation, are being used more and more frequently, the number of wards working with this device increases in the Czech Republic. Just PET/CT belongs to the most modern imaging methods among them. In my thesis I compare the radiation doses to which the radiology assistants in the nuclear medicine ward and radiodiagnostics ward are exposed to. The part of the assessment is also the comparison of the radiation protection in the mentioned wards. From methodology point of view, I compared two wards, the hospital ``Na Homolce{\crqq}, where is situated the PET centre with the hybrid PET/CT device, and ``Úrazová nemocnice{\crqq}, equipped with the CT device. With the approval of the employees of the individual wards the data on the quantity of the examinations were processed for the period from 1. 1. 2008 to 30. 9. 2009. Data on the radiation doses were processed by the National Service of Personal Dosimetry in Prague. The number of staff in the individual wards varied during the monitored period, in common there were 13 people in each ward. Radiation load doses for each person were regularly registered during the monitored period. Dosimeters were used for the registration. The nuclear medicine ward uses personal and fingertip dosimeters. These are evaluated each month. On the contrary, the diagnostics ward - CT ward uses only personal dosimeters, evaluated once in three months. The values are presented in the tables. Comparing the personal dosimetry of the PET centre staff and the computer tomography staff, we come to the following results: Monitored period 1 and {$^3\!/\!_4$} year. Annual doses of the ionizing radiation per the person involved in the computer tomography can reach maximally 0,4mSv in the personal dosimetry. Doses per the representative of the PET centre equal to 2.88mSv per year for the personal dosimeters. The results confirmed the hypothesis assuming that the radiology assistants in the nuclear medicine ward are exposed to higher radiation load in comparison to the radiodiagnostics ward working with the CT device. The results comply with the limits for the radiation staff as stipulated in the notice 307/2002 Coll.
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Staff radiation exposure in application of the PET-CT method
BERTOVÁ, Eva
In my Bachelor-of Science work I have studied the issue of the PET-CT method application and its influence on the radiation exposure of nuclear medicine department staff at Faculty Hospital in Lochotín in Plzeň (FN Plzeň-Lochotín). In the opening chapter, the origin and recent developments in the nuclear medicine is reviewed with special focus on the PET history in the world, the physical principles of PET and the first installations of PET and PET-CT in Czech Republic and FN Plzeň-Lochotín. Then the issue of radiation protection is taken up including its history, the recent status including the relevant legal regulations, the basic principles of radiation protection, the physical methods of protection, exposure monitoring programmes and protection against radiation at the PET-CT section of nuclear medicine department of FN Plzeň-Lochotín. The reason why I chose this subject is the high energy radiation associated with PET-CT requiring special measures to ensure staff protection. The target of this work is comparison of the radiation exposure of the nuclear medicine department staff prior to and following introduction of the PET-CT method and verification of the organisation changes and radiation protection measures adopted. In practical part of my work I compared the values of personal dose equivalents Hp (10) detected with the department staff prior to and following the PET-CT method implementation. The values are shown in tables and graphs. The monthly dose equivalent values detected prior to and following the PET-CT equipment installation have been compared using the statistical method of double sample t-test. The conclusions of this study have been used to verify the efficiency of the radiation protection measures adopted at FN Plzeň-Lochotín, and to compare the status of affairs in Plzeň with those in the Nuclear Medicine Clinic of Medical Faculty and Faculty Hospital in Olomouc and at the PET Centre of the Na Homolce hospital in Prague.
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