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Sohrabi R, Miri-Hakimabad H, Hoseinian-Azghadi E, Vega-Carrillo HR. Age-specific calibration for in vivo monitoring of thyroid: is it necessary? RADIATION AND ENVIRONMENTAL BIOPHYSICS 2022; 61:399-406. [PMID: 35842886 DOI: 10.1007/s00411-022-00984-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 06/26/2022] [Indexed: 06/15/2023]
Abstract
Usually, an age-specific calibration of detectors used for in vivo monitoring of 131I thyroid radioactivity is not performed in practice. This study aimed to investigate the reduction in uncertainty that one can expect if an age-specific calibration is performed. For this, voxel and stylized computational phantoms of the thyroid, corresponding to children at different age groups, were used to simulate the calibration process of 131I detectors used for thyroid monitoring. SCK•CEN physical phantoms were also used for this purpose. Both analytical and Monte Carlo methods (MCNPX version 2.6.0) were used to estimate the counting efficiencies of the considered detectors. The results show that the uncertainties in the assessment of thyroid activity at a distance of 20 cm would be reduced from a range of +8% to +30%, to a range from - 6% to +15% when age-specific calibration was performed. Using a calibration based on thyroids of adults would result in an overestimation of the thyroid activity for children by up to 30% at a detector-neck distance of about 20 cm; a larger overestimation may be expected at closer distances. It is concluded that age-specific calibration of in vivo monitoring systems for the thyroid is important and has to be taken into consideration to improve the reliability of thyroid dose assessment for children.
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Affiliation(s)
- Roghayeh Sohrabi
- Physics Department, Faculty of Science, Ferdowsi University of Mashhad, Azadi square, Mashhad, 91775-1436, Iran
| | - Hashem Miri-Hakimabad
- Physics Department, Faculty of Science, Ferdowsi University of Mashhad, Azadi square, Mashhad, 91775-1436, Iran.
| | | | - Héctor René Vega-Carrillo
- Unidad Academica de Estudios Nucleares de La Universidad Autonoma de Zacatecas, C. Cipres 10, Fracc. La Peñuela, 98068, Zacatecas, Zac, Mexico
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Masiuk S, Chepurny M, Buderatska V, Kukush A, Shklyar S, Ivanova O, Boiko Z, Zhadan N, Fedosenko G, Bilonyk A, Lev T, Talerko M, Kutsen S, Minenko V, Viarenich K, Drozdovitch V. Thyroid doses in Ukraine due to 131I intake after the Chornobyl accident. Report I: revision of direct thyroid measurements. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2021; 60:267-288. [PMID: 33661398 PMCID: PMC8119388 DOI: 10.1007/s00411-021-00896-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
The increased risk of thyroid cancer among individuals exposed during childhood and adolescence to Iodine-131 (131I) is the main statistically significant long-term effect of the Chornobyl accident. Several radiation epidemiological studies have been carried out or are currently in progress in Ukraine, to assess the risk of radiation-related health effects in exposed populations. About 150,000 measurements of 131I thyroid activity, so-called 'direct thyroid measurements', performed in May-June 1986 in the Ukrainian population served as the main sources of data used to estimate thyroid doses to the individuals of these studies. However, limitations in the direct thyroid measurements have been recently recognized including improper measurement geometry and unknown true values of calibration coefficients for unchecked thyroid detectors. In the present study, a comparative analysis of 131I thyroid activity measured by calibrated and unchecked devices in residents of the same neighboring settlements was conducted to evaluate the correct measurement geometry and calibration coefficients for measuring devices. As a result, revised values of 131I thyroid activity were obtained. On average, in Vinnytsia, Kyiv, Lviv and Chernihiv Oblasts and in the city of Kyiv, the revised values of the 131I thyroid activities were found to be 10-25% higher than previously reported, while in Zhytomyr Oblast, the values of the revised activities were found to be lower by about 50%. New sources of shared and unshared errors associated with estimates of 131I thyroid activity were identified. The revised estimates of thyroid activity are recommended to be used to develop an updated Thyroid Dosimetry system (TD20) for the entire population of Ukraine as well as to revise the thyroid doses for the individuals included in post-Chornobyl radiation epidemiological studies: the Ukrainian-American cohort of individuals exposed during childhood and adolescence, the Ukrainian in utero cohort and the Chornobyl Tissue Bank.
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Affiliation(s)
- Sergii Masiuk
- State Institution "National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine", Kyiv, Ukraine
| | - Mykola Chepurny
- State Institution "National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine", Kyiv, Ukraine
| | - Valentyna Buderatska
- State Institution "National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine", Kyiv, Ukraine
| | | | - Sergiy Shklyar
- Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Olga Ivanova
- State Institution "National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine", Kyiv, Ukraine
| | - Zulfira Boiko
- State Institution "National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine", Kyiv, Ukraine
| | - Natalia Zhadan
- State Institution "National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine", Kyiv, Ukraine
| | - Galyna Fedosenko
- State Institution "National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine", Kyiv, Ukraine
| | - Andriy Bilonyk
- State Institution "National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine", Kyiv, Ukraine
| | - Tatiana Lev
- Institute for Safety Problems of Nuclear Power Plants, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Mykola Talerko
- Institute for Safety Problems of Nuclear Power Plants, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Semion Kutsen
- Institute for Nuclear Problems, Belarusian State University, Minsk, Belarus
| | - Victor Minenko
- Institute for Nuclear Problems, Belarusian State University, Minsk, Belarus
| | - Kiryl Viarenich
- Institute for Nuclear Problems, Belarusian State University, Minsk, Belarus
| | - Vladimir Drozdovitch
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 9609 Medical Center Drive, Room 7E548 MSC 9778, Bethesda, MD, 20892-9778, USA.
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Lebacq A, Saizu M, Takahashi M, Isaksson M, Bravo B, Brose J, Csizmadia L, Fojtík P, Kövendiné-Kónyi J, Lünendonk G, Meisenberg O, Mosimann N, Osko J, Pantya A, Saurat D, Taba G, Torvela T, Vagfoldi Z, Vilardi I, Vu I, Youngman M, Zoriy P, Beaumont T, Franck D, Broggio D. European intercomparison on the measurement of l-131 in thyroid of adults and children. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2019.106178] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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