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The Dependency of the Volume Activity of I-131 in a Hospital Sewage Treatment Plant on the Amount of I-131 Used as a Medical Treatment in the Nuclear Medicine Ward
KAMPELSHEIMEROVÁ, Šárka
The subject of the work is radiation protection at a nuclear medicine workplace with a bed section in connection with the therapy of thyroid gland diseases using radioisotope 131I. In the theoretical part, the work briefly deals with the anatomy and pathology of the thyroid gland and ways of therapy, and outlines the basic characteristics of radioisotope 131I and history of nuclear medicine and radiation protection. In the practical part, there is a verification of the efficiency of radiation protection when handling liquid waste and a verification of the correlation of the activity of liquid waste with the activity of radiopharmaceutical administered. The malignant tumours of the thyroid gland constitute 0,5?1 % of all tumoral diseases. Some types of this tumour, which are histologically differentiated, retain the capability of extracting iodine from blood and are thus suitable for being treated using iodine radioisitope. That's why these types of tumour are treated most frequently at nuclear medicine departments. The basis of therapy is the surgical removal of tumoral tissue, usually of the whole thyroid gland, and administration of radioisotope 131I. When treating the thyroid gland, the patient is always hospitalized at a nuclear medicine department with a bed section. Radioisotope 131I is mixed ? and ? emitter and after being administred to a patient, it is the source of radiation danger for hospital personnel, possibly for others individuals. At the same time it is excreted from the organism by urine, stool and sweat. On that score due attention must be paid to safety measures. In view of the magnitude of this problem and the emphasis that is currently laid to protection against ionizing radiation, I chose this issue as a subject of my bachelor's work. The goal of the practical part of the work was to verify whether the limits set by Decree No. 307/2002 Coll., as amended by Decree No. 499/2005 Coll. on radiation protection were observed under the current system of handling liquid waste in the bed section of the Nuclear Medicine Department of the České Budějovice Hospital. Two hypotheses were set: Operation regulations and current programme equipment of the technical installations for the automatic draining of waste water from the bed section of the Nuclear Medicine Department are sufficient for the limits set by Decree not being exceeded; the other hypothesis assumes that the values of the volume activity of waste water in the drainage tank of the hospital's sewage plant conform to the activity of a radiopharmaceutical administered to patients treated at the Nuclear Medicine Department of the České Budějovice Hospital. For the purposes of this work, the activity of waste in the drainage tank of the hospital's sewage plant was measured with a well detector once a week for a period of two month to verify that the activity does not exceed a release level of 455 Bql-1 set in an addendum to Decree No. 307/2002 Coll. It was ascertained by measuring that the average activity of waste in the watched period was 279,8 Bql-1, the highest activity measured on March 18, 2013 being 373 Bql-1. In the watched period, the release activity set by the law was not exceeded in any week. At the same time, the correlation of the values of radioactivity administered with the radioactivity of waste water was proved. Consequently, both hypotheses of the work were proved. The work proved that the limits set by Decree No. 307/2002 Coll., as amended by Decree No. 499/2005 Coll. on radiation protection, were observed under the current system of handling liquid waste in the bed section of the Nuclear Medicine Department of the České Budějovice Hospital.
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The effect of x-ray tube voltage on the initial surface dose.
HYKA, Daniel
Relating to the adoption of the Law No.18/1997 of the Legal Code, the so called ?Atom Law? amended with the Law No. 13/2002 of the Legal Code, the radiation protection regulations were considerably toughen. According to the Paragraph 4 of the Law each subject executing operations resulting in radiation is obliged to ensure priority radiation protection. In addition, each subject is obliged to implement quality assurance system according to the Regulation No.214/1997 of the Legal Code and each subject authorized to handling sources of ionizing radiation is according to the Paragraph 18, Article I, Letter a) of the Atom Law also obliged to monitor the source of ionizing radiation by monitoring, measuring, evaluating and recording relevant figures. The Law No. 18/97 of the Legal Code also imposes the obligation to maintain such level of radiation protection that the life and health hazard and the environmental threats are as low as it is reasonably possible when economic and social views are taken into account. This optimization is attained with the implementation of the quality assurance program, which contains the long-term stability test. One of the steps leading to optimization and reduction of the ionizing radiation dose is correct selection of the load parameters of the X-ray machine. An important factor is the used voltage of the x-ray tube; it affects the input surface kerma, which is the fundamental information for the subsequent estimation of the effective dose. Changing this parameter can considerably effect, or decrease, the absorbed dose for the patients and the staff. Often such conditions arise which necessitate a voltage change, which on the other hand require a change in exposition (mAs or distance). However, we have to keep in mind that increased voltage together with adjusted exposition with the average density maintained the same; will result in lower image contrast, because the x-ray radiation produced with higher voltage reduces the subject contrast. The same applies vice versa, i.e. when voltage is decreased, subject contrast is increased. The objectives of the practical part of the thesis is to find out based on dosimetry measurement using a phantom, what is the effect of the voltage change on the x-ray tube on the increase or decrease of the radiation load on patients during skiagraphic procedures.
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A patient after a diagnostic application of radiopharmaceuticals as a source of radiation - mutual radiation strain of the personnel and patients
MARKOVÁ, Iveta
ABSTRACT A patient after a diagnostic application of radiopharmaceuticals as a source of radiation - mutual radiation strain of the personnel and patients My work focuses on the radiation protection on account of the potential influence of ionizing radiation with its negative effects on a human organism. In my work I concentrated on observing the obtained personal equivalent doses of the ionizing radiation in the Department of Nuclear Medicine in the Hospital of České Budějovice, plc. I also focused on the measurement and assessment of the dose rate obtained by the employees of the Department of Nuclear Medicine in the Hospital of České Budějovice, plc. from treated patients with regard to the distance and type of the applied radiopharmaceutical. The methods chosen for the actual measuring, gathering, recording and assessment of the data are described in a great detail and presented in the methodology of my work. The data obtained from the personal TL dosimeters is registered and filed in the Department of Nuclear Medicine in the Hospital of České Budějovice, plc. on a long term basis. Therefore it enabled me to analyze the equivalent dose of four nurses during the last five years. The results were compared with the figures determined in the regulation 307/2002 of the Code, as amended by regulation 499/2005 of the Code. The results are then clearly presented in tables and graphs. The collected data has confirmed that the values of equivalent doses obtained from the personal TL dosimeters of four nurses working in the Department of Nuclear Medicine in the Hospital of České Budějovice, plc. do not exceed figures determined by the regulation 307/2002 of the Code, as amended by regulation 499/2005 of the Code. The measured dose rates decrease with the distance and are proportional to the activity and type of radiopharmaceutical.
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Radioactive waste management in the department of nuclear medicine
VENCLÍK, Zdeněk
Radioactive waste management in the department of nuclear medicine is a complex process in which it is necessary to obey a number of lawful orders. These are based on physical and chemical properties of the radionuclide sources. At present these regulations particularly include Act No. 18/1997 Coll., on Peaceful utilisation of nuclear energy and ionizing radiation (the Atomic Act) and amendment to and alteration of some related acts in the wording and implementing Decree No. 307/2002 Coll., on Radiation Protection (which repeals Decree No. 184/1997 Coll.) in the wording of Decree No. 499/2005 Coll., which amends the Decree of the Czech National Council for nuclear safety No. 307/2002 Coll., on Radiation Protection. This legislation regulates the management of radioactive waste as a whole and deals with specific radionuclides in the annexes. It is necessary to comply with legislation whether the radioactive waste is generated in the actual production of radionuclides or during their diagnostic and therapeutic applications. All production and application processes give rise to certain materials contaminated with radionuclide sources but without the possibility of their further use. These contaminated and unusable materials are called radioactive waste. Radioactive waste arising from operation of nuclear medicine is basically divided into solid, liquid and gaseous. Solid radioactive waste is collected in refrigerators and lead safe deposits, depending on whether the waste is infectious or not. Liquid waste goes through the process of dilution in most cases, when there is a decrease of the volume activity limits and subsequent discharge to sewer. Gaseous waste is a negligible component of radioactive waste produced at nuclear medicine departments, so it is not often dealt with in more detail. No matter what kind of waste, the process of its disposal has a common goal of reducing its activity below specified limits (clearance levels), so that the waste can be without greater risk moved or released and disposed of as other, non-radioactive waste.
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