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Medycyna Pracy
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2020
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vol. 71
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issue 3
398-398
EN
The original version of the article can be found at http://medpr.imp.lodz.pl/Calibration-of-thermoluminescent-detectors-in-H-p-0-07-units-by-using-an-X-ray-tube,109931,0,2.html.
Medycyna Pracy
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2018
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vol. 69
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issue 3
317-327
EN
Background A radiopharmaceutical is a combination of a non-radioactive compound with a radioactive isotope. Two isotopes: technetium- 99m ($ \text{}^\text{99m}\text{Tc} $) and fluorine-18 ($ \text{}^\text{18}\text{F} $) are worth mentioning on the rich list of isotopes which have found numerous medical applications. Their similarity is limited only to the diagnostic area of applicability. The type and the energy of emitted radiation, the half-life and, in particular, the production method demonstrate their diversity. The $ \text{}^\text{99m}\text{Tc} $ isotope is produced by a short-lived nuclide generator – molybdenum-99 ($ \text{}^\text{99}\text{Mo} $)/$ \text{}^\text{99m}\text{Tc} $, while $ \text{}^\text{18}\text{F} $ is resulting from nuclear reaction occurring in a cyclotron. A relatively simple and easy handling of the $ \text{}^\text{99}\text{Mo} $ \text{}^\text{99m}\text{Tc} $ generator, compared to the necessary use a cyclotron, seems to favor the principle of optimizing the radiological protection of personnel. The thesis on the effect of automation of both the $ \text{}^\text{18}\text{F} $ isotope production and the deoxyglucose labelling process on the optimization of radiological protection of workers compared to manual procedures during handling of radiopharmaceuticals labelled with $ \text{}^\text{99m}\text{Tc} $ need to be verified. Material and Methods Measurements of personal dose equivalent Hp(0.07) were made in 5 nuclear medicine departments and 2 radiopharmaceuticals production centers. High-sensitivity thermoluminescent detectors (LiF: Mg, Cu, P – MCP-N) were used to determine the doses. Results Among the activities performed by employees of both $ \text{}^\text{18}\text{F} $-fluorodeoxyglucose ($ \text{}^\text{18}\text{F} $-FDG) production centers and nuclear medicine departments, the manual quality control procedures and labelling of radiopharmaceuticals with $ \text{}^\text{99m}\text{Tc} $ isotope manifest the greatest contribution to the recorded Hp(0.07). Conclusions The simplicity of obtaining the $ \text{}^\text{99m}\text{Tc} $ isotope as well as the complex, but fully automated production process of the $ \text{}^\text{18}\text{F} $-FDG radiopharmaceutical optimize the radiation protection of workers, excluding manual procedures labelling with $ \text{}^\text{99m}\text{Tc} $ or quality control of $ \text{}^\text{18}\text{F} $-FDG. Med Pr 2018;69(3):317–327
PL
Wstęp Radiofarmaceutyk to produkt będący połączeniem niepromieniotwórczego związku chemicznego i znacznika izotopowego. Na bogatej liście izotopów mających zastosowane w medycynie na uwagę zasługują 2 – technet-99m ($ \text{}^\text{99m}\text{Tc} $) i fluor-18 ($ \text{}^\text{18}\text{F} $). Ich podobieństwo ogranicza się jedynie do diagnostycznego obszaru stosowalności, a dzieli je m.in. rodzaj i energia emitowanego promieniowania, czas połowicznego rozpadu czy w szczególności sposób produkcji. Izotop $ \text{}^\text{99m}\text{Tc} $ uzyskuje się dzięki generatorom nuklidów krótkożyciowych – molibdenu-99 ($ \text{}^\text{99}\text{Mo} $)/$ \text{}^\text{99m}\text{Tc} $, a $ \text{}^\text{18}\text{F} $ powstaje w reakcji jądrowej zachodzącej w cyklotronie. Stosunkowo łatwy sposób obsługi generatora $ \text{}^\text{99}\text{Mo} $/$ \text{}^\text{99m}\text{Tc} $ w porównaniu z koniecznością wykorzystania cyklotronu wydaje się sprzyjać zasadzie optymalizacji ochrony radiologicznej personelu. Weryfikacja tezy dotyczącej wpływu automatyki zarówno produkcji znacznika $ \text{}^\text{18}\text{F} $, jak i procesu znakowania deoksyglukozy na zoptymalizowanie ochrony radiologicznej pracowników w porównaniu z manualnymi procedurami wykonywanymi podczas znakowania preparatów izotopem $ \text{}^\text{99m}\text{Tc} $. Materiał i metody Dawki równoważne Hp(0,07) zmierzono w 5 zakładach medycyny nuklearnej i 2 ośrodkach produkujących znaczniki pozytonowe, w szczególności $ \text{}^\text{18}\text{F} $. W pomiarach dozymetrycznych wykorzystano wysokoczułe detektory termoluminescencyjne wykonane z fluorku litu (LiF: Mg, Cu, P – MCP-N). Wyniki Wśród czynności wykonywanych przez pracowników zarówno placówek produkujących $ \text{}^\text{18}\text{F} $-fluorodeoksyglukozę ($ \text{}^\text{18}\text{F} $-FDG), jak i zakładów medycyny nuklearnej manualne procedury kontroli jakości oraz znakowanie preparatu mają największy wkład do zarejestrowanych wartości dawek Hp(0,07). Wnioski Prosty sposób uzyskania znacznika $ \text{}^\text{99m}\text{Tc} $ podobnie jak złożony (choć w pełni zautomatyzowany) proces produkcji $ \text{}^\text{18}\text{F} $-FDG optymalizuje ochronę radiologiczną personelu z wyłączeniem manualnych procesów znakowania związków chemicznych $ \text{}^\text{99m}\text{Tc} $ bądź kontroli jakości $ \text{}^\text{18}\text{F} $-FDG. Med. Pr. 2018;69(3):317–327
Medycyna Pracy
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2019
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vol. 70
|
issue 6
669-673
EN
Background The method of measuring doses based on the thermoluminescence phenomenon is not an absolute method. For this reason, to obtain correct results, it is necessary to calibrate detectors in the known radiation field. This paper presents a method for calibrating thermoluminescent detectors used in the measurement of personal dose equivalents (Hp(0.07)) obtained by nuclear medicine facility personnel when handling the $\text{}^{99m} \text{Tc}$ radionuclide. Material and Methods The authors used self-developed high-sensitivity thermoluminescent detectors and a HF320C X-ray unit, as well as a rod phantom. Dosimeters were calibrated in accordance with the ISO 4037-3 standard. During the measurements a vial containing a $\text{}^{99m} \text{Tc}$ radionuclide with well-known activity was also used. The energy characteristics were supplemented by using a ¹³⁷Cs source (irradiator ⁶⁰Co/¹³⁷Cs). Results The value of the calibration coefficient for 118 keV energy energy was (1.90±0.02)×10⁻⁵ mSv/imp. Taking into account the correction factor specified for of 140 keV energy at 0.962, the value of the calibration coefficient for 140 keV energy was determined as (1.83±0.02)×10⁻⁵ mSv/imp. Conclusions Verification of the calibration coefficient determined for 140 keV energy carried out with a vial containing a $\text{}^{99m} \text{Tc}$ radionuclide confirmed the correctness of the procedure. Med Pr. 2019;70(6):669–73
EN
Background The use of X-ray in dental procedures causes exposure of the patient to ionizing radiation. This exposure depends primarily on the parameters used in tooth examination. The aim of the study was to determine the patients exposure and to assess the technical condition of X-ray tubes. Material and Methods Seventeen hundred dental offices were covered by the questionnaire survey and 740 questionnaires were sent back. Direct measurements were performed in 100 units by using the thermoluminescent detectors and X-ray films. Results The results showed that the most commonly used exposure time is 0.22±0.16 s. The average entrance dose for the parameters used most commonly by dentists is 1.7±1.4 mGy. The average efficiency of X-ray tube estimated on the basis of exposures is 46.5±23.7 μGy/mAs. Conclusions The study results indicate that the vast majority of X-ray tubes meet the requirements specified in the binding regulations. Med Pr 2017;67(4):491–496
PL
Wstęp Stosowanie w procedurach stomatologicznych promieniowania rentgenowskiego (rtg.) powoduje narażenie pacjenta na promieniowanie jonizujące. Wielkość tego narażenia zależy przede wszystkim od parametrów stosowanych przy prześwietleniu zęba. Celem badań było określenie wielkości dawek, na jakie narażeni są pacjenci, oraz ocena stanu technicznego aparatów rtg. Materiał i metody Badaniami ankietowymi objęto 1700 gabinetów stomatologicznych. Ankiety odesłało 740 jednostek. Pomiary bezpośrednie wykonano w 100 gabinetach. Pomiary wykonano za pomocą detektorów termoluminescencyjnych i klisz rtg. Wyniki W przeprowadzonych badaniach stwierdzono, że najczęściej stosowany czas ekspozycji wynosi 0,22±0,16 s. Średnia dawka wejściowa dla parametrów najczęściej stosowanych przez stomatologów to 1,7±1,4 mGy. Średnia wydajność lampy rtg. oszacowana na podstawie wykonanych ekspozycji wynosi 46,5±23,7 μGy/mAs. Wnioski Jak wynika z przeprowadzonych badań, znakomita większość aparatów rtg. punktowych spełnia wymagania określone w przepisach. Med. Pr. 2017;68(4):491–496
EN
Objectives Contemporary dental radiology offers a wide spectrum of imaging methods but it also contributes to an increase in the participation of dental radiological diagnosis in the patient’s exposure to ionizing radiation. The aim of this study is to determine the absorbed doses of the brain, spinal column, thyroid and eye lens for patients during panoramic radiography, cephalometric radiography and cone beam computed tomography (CBCT). Material and Methods The thermoluminescent dosimetry and anthropomorphic phantom was used for measuring the doses. The 15 panoramic, 4 cephalometric and 4 CBCT exposures were performed by placing high-sensitivity thermoluminescent detectors (TLD) in 18 anatomical points of the phantom. Results The maximum absorbed dose recorded during performed measurements corresponds to the point representing the brainstem and it is 10 mGy. The dose value recorded by the TLD placed in the thyroid during CBCT imaging in relation to the panoramic radiography differs by a factor of 13.5. Conclusions Cone beam computed tomography, in comparison with panoramic or cephalometric imaging technique, provides higher radiation doses to the patients. Int J Occup Med Environ Health 2017;30(5):705–713
EN
Background Thermoluminescent detectors, type MTS-6, containing isotope ⁶Li (lithium) are sensitive in the range of thermal neutron energy; the ²³⁹Pu-Be (plutonium-and-beryllium) source emits neutrons in the energy range from 1 to 11 MeV. These seemingly contradictory elements may be combined by using the paraffin moderator, a determined density of thermal neutrons in the paraffin block and a conversion coefficient neutron flux to kerma, not forgetting the simultaneous registration of the photon radiation inseparable from the companion neutron radiation. The main aim of this work is to present the idea of calibration of thermoluminescent detectors that consist of a ⁶Li isotope, by using ²³⁹Pu-Be neutron radiation source. Material and Methods In this work, MTS-6 and MTS-7 thermoluminescent detectors and a plutonium-and-beryllium (²³⁹Pu-Be) neutron source were used. Paraffin wax fills the block, acting as a moderator. The calibration idea was based on the determination of dose equivalent rate based on the average kerma rate calculated taking into account the empirically determined function describing the density of thermal neutron flux in the paraffin block and a conversion coefficient neutron flux to kerma. Results The calculated value of the thermal neutron flux density was 1817.5 neutrons/cm²/s and the average value of kerma rate determined on this basis amounted to 244 μGy/h, and the dose equivalent rate 610 μSv/h. The calculated value allowed for the assessment of the length of time of exposure of the detectors directly in the paraffin block. Conclusions The calibration coefficient for the used batch of detectors is (6.80±0.42)×10⁻⁷ Sv/impulse. Med Pr 2017;68(6):705–710
EN
Background There are about 200 underground tourist routes in Poland. There are caves, mines or underground structures. This paper presents the results of the research intended to identify the extent of the occurrence of radon concentrations in underground areas of tourist routes. Material and Methods We conducted the measurement of periodic concentrations of radon (1–2 months) in the summer using type Tastrak trace detectors. We determined the average concentrations of radon in air in 66 underground tourist routes in Poland. Results The research results comprise 259 determinations of average radon concentrations in 66 routes. The arithmetic average of the results was 1610 Bqm⁻³, and the maximum measured concentration was over 20 000 Bqm⁻³. The minimum concentration was 100 Bqm⁻³ (threshold method) considering the arithmetic average of the measurements. It was found that in 67% of the routes, the average concentration of radon has exceeded 300 Bqm⁻³ and in 22 underground routes it exceeded 1000 Bqm⁻³. Conclusions Radon which occurs in many Polish underground tourist routes may be an organizational, legal and health problem. It is necessary to develop a program of measures to reduce radon concentrations in underground routes, especially routes located in the former mines. Med Pr 2015;66(4):557–563
PL
Wstęp W Polsce funkcjonuje około 200 podziemnych tras turystycznych. Są to jaskinie, kopalnie oraz podziemne budowle. W niniejszej pracy przedstawiono wyniki badań mających na celu rozpoznanie zakresu występowania stężeń radonu we wnętrzach podziemnych tras turystycznych. Materiał i metody W celu oszacowania stopnia zagrożenia przeprowadzono okresowe (1–2-miesięczne) pomiary stężeń radonu. Wykonano je w okresie letnim za pomocą detektorów śladowych typu Tastrak. Określono średnie stężenie radonu w powietrzu w 66 podziemnych trasach turystycznych w Polsce. Wyniki W wyniku przeprowadzonych badań uzyskano 259 pomiarów średnich stężeń radonu. Średnia arytmetyczna wyników wyniosła 1610 Bqm⁻³, maksymalne zmierzone stężenie – ponad 20 tys. Bqm⁻³, a stężenie minimalne – 100 Bqm⁻³ (próg czułości metody). Stwierdzono, że w 67% tras średnie stężenie radonu przekroczyło wartość 300 Bqm⁻³, natomiast w 22 podziemnych trasach przekroczyło 1000 Bqm⁻³. Wnioski Występujący w podziemnych trasach turystycznych radon w wielu przypadkach może stanowić problem organizacyjno-prawny i zdrowotny. Należy opracować program działań, których celem będzie obniżenie stężeń radonu w podziemnych trasach, szczególnie zlokalizowanych w zamkniętych kopalniach. Med. Pr. 2015;66(4):557–563
EN
Objectives While working with cyclotrons used for the production of radiopharmaceuticals, workers can experience significant exposure to the adverse effects of ionizing radiation. The aim of this paper was to determine the typical level of such exposure received by such personnel while servicing cyclotrons. Material and Methods Exposure was assessed using TLD detectors placed in an anthropomorphic phantom, as well as dose meter to determine whole body and eye lens exposure. The phantom was placed in locations receiving the greatest exposure to ionizing radiation during service activities. The time spent by employees during servicing was assessed based on routine visits by service technicians. The obtained results were compared with readings of detectors worn by employees during service activities. Results The highest equivalent doses in the thoracic area were found to be received by the lungs (211.16 μSv/year). In the head and neck area, the highest dose was measured in the eye lens (3410 μSv/year). The effective dose for the whole body was found to be 1154.4 μSv/year, based on the phantom, and 149 μSv per service visit (1192 μSv/year), based on the dose meters carried by the workers. Conclusions Service workers are exposed to significant doses of ionizing radiation, representing a clear radiological protection issue. To reduce exposure to eye lenses, it is recommended to use protective goggles when working with highly-radioactive elements.
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