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Furuta, Hiroshige*; Sato, Kaoru; Nishide, Akemi*; Kudo, Shinichi*; Saigusa, Shin*
Health Physics, 121(5), p.471 - 483, 2021/11
Times Cited Count：1 Percentile：15.7(Environmental Sciences)Low dose radiation induced "health effects" containing cancer risk for a Japanese radiation worker cohort is epidemiologically evaluated using the personal dose equivalent (Hp(10)). On the other hand, Hp(10) is not recommended for epidemiological evaluation of cancer risks, since the Hp(10) is widely used for radiological protection purposes. In addition, the cancer risk depends on organ doses rather than Hp(10). Thus, we developed a new method for estimating organ doses from Hp(10) of radiation workers. The developed method enables epidemiological analysis against Japanese radiation workers by considering the response characteristics of personal dosimeters, exposure geometry and energy, and body size of radiation workers in Japan. In the future, we will reconstruct organ dose conversion factor and will evaluate the risk of cancer mortality and morbidity using the organ dose in Japan.
Sato, Kaoru; Takahashi, Fumiaki
Hoken Butsuri, 52(4), p.247 - 258, 2017/12
Organ doses for dose assessment in radiation protection are derived from ICRP reference phantoms (Male:RCP-AM, Female:RCP-AF) with standard Caucasian physiques. In adult, Japanese are smaller than Caucasian. To study impact of differences in physiques between Caucasian and Japanese on organ doses, we previously constructed Japanese phantoms (Male:JM-103, Female:JF-103) with average adult Japanese physiques. In addition, adult Japanese physiques have also wide distribution. Thus, we newly modeled DJM (Male) and DJF (Female) with 8 physiques by changing the perimeters of JM-103 and JF-103. Organ doses due to external photon irradiation of DJM and DJF were calculated, and were compared with those of RCP-AM and RCP-AF. In ISO geometry at 0.3 MeV, it was found that doses of breast, colon, lung, stomach, gonad, urinary bladder, esophagus, liver and thyroid in DJM and DJF with physiques, which are applicable to most adult Japanese, agreed with those of RCP-AM and RCP-AF within 10%.
Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki
JAEA-Data/Code 2016-013, 48 Pages, 2016/12
JAEA-Data-Code-2016-013.pdf:1.3MB
JAEA-Data-Code-2016-013-appendix(CD-ROM).zip:0.47MB
In the 2007 Recommendations of the International Commission on Radiological Protection (ICRP), an effective dose is defined as a sum of equivalent doses which are calculated by using male and female reference phantoms based on Caucasian physiological data and averaged over the sexes by tissue weighting factors. Specific absorbed fractions (SAFs), which are essential for internal dosimetry, depend on the body weight and organ masses of phantoms. Then, the dose coefficients, which are committed effective doses per unit intake of radionuclides, developed by ICRP on the basis of the 2007 Recommendations reflect the physical characteristics of Caucasians and are averaged over the sexes. Meanwhile, the physiques of adult Japanese are generally smaller than those of adult Caucasians, and organ masses are also different from each other. Knowledge of the influence of race differences on dose coefficients is important to apply the sex averaged dose coefficients of ICRP to the Japanese system of radiation protection. In this study, SAFs for 25 kinds of mono-energetic electrons and photons ranging from 10 keV to 10 MeV were calculated about the combinations of 67 source regions and 42 target organs using the average adult Japanese female phantom, JF-103, incorporated with a general purpose radiation transport code, MCNPX 2.6.0. The data of this report and the previously published data of JM-103 are applicable to evaluate sex-specific and sex-averaged dose coefficients reflecting the physical characteristics of the average adult Japanese for intakes of all radionuclides not to emit other than photons and electrons.
Takahashi, Fumiaki; Sato, Kaoru; Endo, Akira; Ono, Koji*; Ban, Nobuhiko*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Yoshitake, Takayasu*; Kai, Michiaki*
Health Physics, 109(2), p.104 - 112, 2015/08
Times Cited Count：8 Percentile：55.87(Environmental Sciences)A dosimetry system, named WAZA-ARI, is developed to assess accurately radiation doses to persons from Computed Tomography (CT) examination patients in Japan. Organ doses were prepared to application to dose calculations in WAZA-ARI by numerical analyses using average adult Japanese human models with the Particle and Heavy Ion Transport code System (PHITS). Experimental studies clarified the radiation configuration on the table for some multi-detector row CT (MDCT) devices. Then, a source model in PHITS could specifically take into account for emissions of X-ray in each MDCT device based on the experiment results. Numerical analyses with PHITS revealed a concordance of organ doses with human body size. The organ doses by the JM phantoms were compared with data obtained using previously developed systems. In addition, the dose calculation in WAZA-ARI were verified with previously reported results by realistic NUBAS phantoms and radiation dose measurement using a physical Japanese model. The results implied that analyses using the Japanese phantoms and PHITS including source models can appropriately give organ dose data with consideration of the MDCT device and physiques of typical Japanese adults.
Takahashi, Fumiaki; Yamaguchi, Yasuhiro
Radiation Risk Assessment Workshop Proceedings, p.71 - 78, 2003/00
Conversion from tooth enamel dose to organ doses against external photon exposure were studied in order to develop a method that can retrospectively estimate organ doses by the Electron Spin Resonance (ESR) dosimetry using tooth samples. Monte Carlo calculations using EGS4 code were performed to obtain dose to tooth enamel and organ doses by using a modified MIRD-type phantom. The Electron Spin Resonance (ESR) dosimetry using tooth samples and dose measurements using thermo-luminescence dosimeters (TLDs) were also carried out to examine dose to teeth region with a realistic physical phantom. A Voxel-type phantom was constructed from CT images of the physical phantom. Monte Carlo calculations with the Voxel-type phantom were performed to verify the results of the experiments and enamel doses calculated by use of the modified MIRD-type phantom. The obtained data are to be useful for the retrospective assessment of individual dose in past exposure events by the ESR dosimetry with tooth enamel.
Takahashi, Fumiaki; Yamaguchi, Yasuhiro; Iwasaki, Midori*; Miyazawa, Chuzo*; Hamada, Tatsuji*; Saito, Kimiaki
Journal of Nuclear Science and Technology, 39(9), p.964 - 971, 2002/09
Times Cited Count：6 Percentile：39.48(Nuclear Science & Technology)Conversion from tooth enamel dose to organ doses was analyzed to establish a method of retrospective individual dose assessment against external photon exposure by the Electron Spin Resonance (ESR) dosimetry. Dose to tooth enamel was obtained by Monte Carlo calculations using a modified MIRD-type phantom. The calculated tooth enamel doses were verified by measurements with thermo-luminescence dosimeters inserted in a physical head phantom. Energy and angular dependences of tooth enamel dose were compared with those of other organ doses. Additional Monte Carlo calculations were performed to study the effects of human model on the tooth enamel dose with a voxel-type phantom, which was based on CT images of the physical phantom. The data derived with the modified MIRD-type phantom were applied to convert from tooth enamel dose to organ doses against external photon exposure in a hypothesized field, where scattered radiations were taken into account. The results indicated that energy distribution of photons incident to a human body should be required to evaluate precisely individual dose by the ESR dosimetry using teeth.
Takahashi, Fumiaki; Yamaguchi, Yasuhiro; Iwasaki, Midori*; Miyazawa, Chuzo*; Hamada, Tatsuji*
Radiation Protection Dosimetry, 95(2), p.101 - 108, 2001/09
Times Cited Count：27 Percentile：85.67(Environmental Sciences)An analysis of doses to tooth enamel and to organs was carried out to develop a method that can predict the organ doses and the effective dose by the Electron Spin Resonance (ESR) dosimetry using tooth samples for external photon exposure. Absorbed dose to tooth enamel and organ doses were obtained by Monte Carlo calculations using EGS4 code in combination with a mathematical human model with a newly defined teeth-part. The calculations gave quantitative relations between tooth enamel dose and organ doses for some cases of external photon exposure. It was also found that tooth enamel dose depends more significantly on energy of incident photons than the other organ dose or the effective dose. The obtained data are to be useful for the assessment of individual dose in past exposure events by the ESR dosimetry with tooth enamel.
Tsuda, Shuichi; Endo, Akira; Yamaguchi, Yasuhiro; Sato, Osamu*
KEK Proceedings 2000-20, p.40 - 47, 2000/12
no abstracts in English
Tsuda, Shuichi; Endo, Akira; Yamaguchi, Yasuhiro; Sato, Osamu*
Proceedings of 10th International Congress of the International Radiation Protection Association (IRPA-10) (CD-ROM), 6 Pages, 2000/05
no abstracts in English
Tsuda, Shuichi; Endo, Akira; Yamaguchi, Yasuhiro; Sato, Osamu*
KEK Proceedings 99-15, p.91 - 97, 1999/10
no abstracts in English
Yamaguchi, Yasuhiro
JAERI-M 90-235, 69 Pages, 1991/01
no abstracts in English
Saito, Kimiaki; N.Petoussi*; Zankl, M.*; R.Veit*; P.Jacob*; G.Drexler*
GSF-2-90, 119 Pages, 1990/01
no abstracts in English
-raysNihon Genshiryoku Gakkai-Shi, 21(9), p.705 - 709, 1979/00
Times Cited Count：0no abstracts in English
Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki
no journal, ,
Effective doses based on ICRP 2007 Recommendations are evaluated using sex averaged equivalent doses. On the other hand, it is required that the situations of exposure are considered as possible in estimating doses for radiation accidents and medical interventions. Then, there are sex specific organs and differences between males and females in masses and positions in bodies of organs (physical characteristics). It is useful to reveal an impact of these differences in physical characteristics on dose estimation. In this study, a comparison was made with organ doses between male and female using photon and electron SAFs based on Japanese adult male and female phantoms (male: JM-103, female: JF-103), which have average physiques and organ masses of adult Japanese, and the recent nuclear decay data and biokinetic models of ICRP. As a result, it is revealed that several tens of percent of discrepancies in organ doses between male and female was caused by sex differences in physical characteristics.
Sato, Kaoru; Takahashi, Fumiaki
no journal, ,
Organ doses, which are basis of dose assessment in radiation protection, are derived from ICRP reference phantoms (Male: RCP-AM, Female: RCP-AF) with body physiques of standard Caucasian. In adult, Japanese body physiques are smaller than those of Caucasian. To study impact of application of organ doses of RCP-AM and RCP-AF to dose assessment of adult Japanese, we constructed Japanese male (JM-103) and female (JF-103) phantoms with body physiques of average adult Japanese. In addition, body physiques of adult Japanese have also wide distribution. Therefore, we newly constructed DJM (Male) and DJF (Female) with 8 body physiques by changing bust, chest, waist and hip of JM-103 and JF-103. Organ doses due to external photon irradiation of DJM and DJF were calculated, and were compared with those of RCP-AM and RCP-AF. In ISO geometry at 0.3 MeV and ROT geometry at 0.6 MeV, it was found that colon doses of DJM and DJF with body physiques, which are applicable to most adult Japanese, agreed with those of RCP-AM and RCP-AF within 10 %.
Sato, Kaoru; Takahashi, Fumiaki; Koba, Yusuke*; Ono, Koji*; Yoshitake, Takayasu*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Kasahara, Tetsuji*; Okuda, Yasuo*; Nakada, Yoshihiro*; et al.
no journal, ,
JAEA is now developing CT dose calculator named WAZA-ARIv2 in cooperation with the National Institute of Radiological Sciences. WAZA-ARIv2 has been opened to the public as full-dress uses on January 2015. WAZA-ARIv2 can perform dose assessment against 4 different body physiques by using the organ dose database, which were constructed on the basis of adult Japanese phantoms with 4 body sizes (-2
, average, +2, +5). In this study, it was found that salivary gland doses are independent on BMI, whereas lung doses are dependent on BMI. The differences in the effects of BMI on absorbed doses between salivary glands and lungs might be caused by the difference in thickness of subcutaneous soft tissues between head and thorax.
-ray irradiation geometriesTsujimura, Norio; Hoshi, Katsuya; Momose, Takumaro
no journal, ,
no abstracts in English
Endo, Akira
no journal, ,
Individual doses for the Life Span Study (LSS) of atomic bomb survivors have been estimated using the Dosimetry System 2002 (DS02). DS02 estimates individual doses using organ dose database calculated by three age-specific mathematical phantoms (infant, child and adult) developed in 1980s, distance from the hypocenter, and shielding conditions. Nowadays more anatomically realistic phantoms, voxel type and polygon mesh type, have been developed, and the use of these phantoms will improve assessment of organ doses of the atomic bomb survivors. The study compares organ doses calculated using mathematical and voxel phantoms of adult and quantifies dosimetric impacts of the use of the new phantoms on the assessment of organ doses.
Sato, Kaoru; Takahashi, Fumiaki; Koba, Yusuke*; Ono, Koji*; Yoshitake, Takayasu*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Kasahara, Tetsuji*; Okuda, Yasuo*; Nakada, Yoshihiro*; et al.
no journal, ,
WAZA-ARIv2 is developed as the web-based open system for CT dose calculator under joint research of JAEA, NIRS (now, QST) and Oita University of Nursing and Health Sciences. WAZA-ARIv2 can provide organ doses under consideration of the body physiques (BMI = 18, 22, 28, 37) of patients with average height of adult Japanese by using voxel phantoms developed by JAEA. In this study, we analyzed the relationship between variations of organ doses and body indices. It was found that effects of weight variations on organ doses were larger than those of height variations. Generally, thickness of the subcutaneous soft tissues is easily changed by variations of weight rather than those of height. This fact may cause the differences in variations of organ doses between weight and height.
Sato, Kaoru; Satoh, Daiki; Takahashi, Fumiaki; Furuta, Takuya
no journal, ,
Organ doses, which are basis of dose assessment in radiation protection, are derived from ICRP phantoms (Male: RCP-AM, Female: RCP-AF) with body physiques of standard Caucasian. In adult, Japanese have small size body, compared with Caucasian. Considering the physiques of Japanese is very important, when organ doses of RCP-AM and RCP-AF are applicable for constructing of radiation protection standard in Japan. So far, we reported the dosimetric characteristics of adult Japanese with various body sizes, which were irradiated with photons. In this study, we analyzed the impact of body sizes on organ doses due to external neutron irradiation. In analysis, we utilized the male and female phantoms with 3 body physiques by changing busts, chests, waists and hips of JM-103 and JF-103. In rotational geometry at 3 MeV, it was found that colon doses of adult Japanese phantoms with body sizes, which are applicable to most adult Japanese, agreed with those of RCP-AM and RCP-AF within 20%.
