@article{oai:repo.qst.go.jp:00049357,
 author = {Kunishima, Naoaki and Tani, Kotaro and Kurihara, Osamu and Kim, Eunjoo and Nakano, Takashi and Kishimoto, Riwa and Tsuchiya, Hiroki and Omatsu, Tokuhiko and Tatsuzaki, Hideo and Tominaga, Takako and Watanabe, Sadahiro and Ishigure, Nobuhito and 明石, 真言 and Kunishima, Naoaki and Tani, Kotaro and Kurihara, Osamu and Eunjoo, Kim and Nakano, Takashi and Kishimoto, Riwa and Tsuchiya, Hiroki and Omatsu, Tokuhiko and Tatsuzaki, Hideo and Tominaga, Takako and Sadahiro, Watanabe and Ishigure, Nobuhito and Akashi, Makoto},
 issue = {5},
 journal = {Health physics},
 month = {Dec},
 note = {As a response to the Tokyo Electric Power Company’s (TEPCO’s) Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011, seven TEPCO workers whose exposure doses were expected to be > 250 mSv (a tentative dose limit stipulated by the Japanese central authority) attended Japan’s National Institute for Radiological Sciences (NIRS) for additional internal dose measurements. The NIRS examination revealed that these workers’ internal doses came mainly from their intake of the radioisotope iodine-131 (131I) during emergency operations. In this study we performed numerical simulations based on individual volume-pixel (voxel) phantoms of six of the seven workers for a more sophisticated evaluation of their internal doses, taking into account the individual thyroid size and other specific parameters. The voxel phantoms were created from magnetic resonance imaging (MRI) scan images. As a result, the individual thyroid volumes ranged from 6.5 to 28.2 cm3, and were considerably smaller than the reference value (~20 cm3) adopted in the International Commission on Radiation Protection’s (ICRP’s) dosimetric model for four of the six subjects. Compared to the original estimates of the thyroid absorbed dose, our preliminary evaluation revealed values that were increased by approx. threefold or decreased by 30% at maximum. A wide difference in the individual thyroid size would be one of the significant modifiers in the current dose estimation of subjects of the ongoing epidemiological study project. The present simulations also provided evidence that the direct thyroid measurements by the NIRS to determine the workers’ 131I thyroid contents were sufficiently accurate.},
 pages = {647--656},
 title = {Numerical Simulation Based on Individual Voxel Phantoms for a Sophisticated Evaluation of Internal Doses Mainly From 131I in Highly Exposed Workers Involved in the TEPCO Fukushima Daiichi NPP Accident},
 volume = {116},
 year = {2018}
}