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Matsuya, Yusuke; McMahon, S. J.*; Butterworth, K. T.*; Naijo, Shingo*; Nara, Isshi*; Yachi, Yoshie*; Saga, Ryo*; Ishikawa, Masayori*; Sato, Tatsuhiko; Date, Hiroyuki*; et al.
Physics in Medicine & Biology, 66(7), p.075014_1 - 075014_11, 2021/04
Times Cited Count：4 Percentile：47.6(Engineering, Biomedical)Hypoxic cancer cells within solid tumours show radio-resistance, leading to malignant progression in fractionated radiotherapy. When prescribing dose to tumours under heterogeneous oxygen pressure with intensity-modulated radiation fields, intercellular signalling could have an impact on radiosensitivity between in-field and out-of-field cells. However, the impact of hypoxia on radio-sensitivity under modulated radiation intensity remains uncertain. In this study, we investigate the impact of hypoxia on in-field and out-of-field radio-sensitivities using two types of cancer cells. These in vitro measurements indicate that hypoxia apparently impacts out-of-field cells, although the OER values in out-of-field cells were smaller compared to those for in-field and uniformly irradiated cells. These decreased radio-sensitivities of out-of-field cells were shown as a consistent tendency for both DSB and cell death endpoints, suggesting that radiation-induced intercellular communication is of importance in treatment planning with intensity-modulated radiotherapy.
Matsuya, Yusuke; McMahon, S. J.*; Ghita, M.*; Yoshii, Yuji*; Sato, Tatsuhiko; Date, Hiroyuki*; Prise, K. M.*
Scientific Reports (Internet), 9(1), p.9483_1 - 9483_12, 2019/07
Times Cited Count：13 Percentile：65.07(Multidisciplinary Sciences)In radiotherapy, intensity modulated radiation fields and complex dose-delivery are used to prescribe doses to tumors. Here, we analyzed the impact of modulated field on radio-sensitivity and cell recovery during irradiation time. The dose was delivered to either 50% of the area of the flask containing cells (half-field) or 100% of the flask (uniform-field). We also modelled cell-killing considering dose-rate effects and intercellular signals. It is found that (i) in-field cell survival under half-field exposure is higher than uniform-field exposure even with the same dose; (ii) the importance of sub-lethal damage repair in normal human skin fibroblast cells under the half-field is reduced; (iii) the increase of cell survival under half-field is predominantly attributed to not rescue effects (increased repair) but protective effects (reduced initial DNA lesion yield). These findings provide new understanding of radio-sensitivity for hit and non-hit cells under non-uniform exposure.
Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.
EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01
Times Cited Count：13 Percentile：99.06(Quantum Science & Technology)Saito, Kimiaki; Saito, Hidetoshi*; Kunieda, Etsuo*; Narita, Yuichiro*; Myojoyama, Atsushi*; Fujisaki, Tatsuya*; Kawase, Takatsugu*; Kaneko, Katsutaro*; Ozaki, Masahiro*; Deloar, H. M.*; et al.
Joho Shori, 48(10), p.1081 - 1088, 2007/10
no abstracts in English
= +1 Baryon resonance in photoproduction from the neutronNakano, Takashi*; Ahn, D. S.*; Ahn, J. K.*; Akimune, Hidetoshi*; Asano, Yoshihiro; Chang, W. C.*; Date, S.*; Ejiri, Hiroyasu*; Fujimura, Hisako*; Fujiwara, Mamoru; et al.
Physical Review Letters, 91(1), p.012002_1 - 012002_4, 2003/07
Times Cited Count：1006 Percentile：99.86(Physics, Multidisciplinary)no abstracts in English
Matsuya, Yusuke; McMahon, S.*; Ghita, M.*; Sato, Tatsuhiko; Yoshii, Yuji*; Kai, Takeshi; Date, Hiroyuki*; Prise, K.*
no journal, ,
Under non-uniform exposure caused in modern radiotherapy (i.e., IMRT, VMAT and Cyberknife), intercellular signalling and DNA repair during irradiation play important roles in the induction of increased cell survival (radio-resistance). However, the underlying mechanisms which induce radio-resistance following such exposures remain unclear. In this study, to investigate the impact of modulated radiation intensity on radio-sensitivity, we performed cell experiments and developed model analysis, and evaluated the cell survival and DNA strand break yield. In this experiment, the dose was delivered to 50% of the area of the flask containing cells. In model development, we also modelled cell responses considering dose-rate effects and signaling effects. As a result, in comparison with uniform-field exposure, the non-uniform irradiation reduces the initial yield of DNA damage in directly irradiated cells, leading to higher cell survival, whilst the importance of cell recovery during irradiation (dose-rate effects) was reduced. This work suggests that the radio-resistance in directly irradiated cells is predominantly attributed to initial protective effects after non-uniform irradiation.
Dong, F.*; Chen, S.*; Demachi, Kazuyuki*; Hashidate, Ryuta; Takaya, Shigeru
no journal, ,
Piping and Instrumentation Diagrams contain information about the piping and process equipment together with the instrumentation and control devices, which is essential to the design and management of Nuclear Power Plants. There are abundant complex objects on P&IDs, with imbalanced distribution of these objects and their linked information across different diagrams. Therefore, the content of P&IDs is generally extracted and analyzed manually, which is time consuming and error prone. To efficiently address these issues, we integrate state-of-the-art deep learning-based object detection and Optical Character Recognition models to automatically extract link information from P&IDs. Besides, we propose a novel image pre-processing approach using sliding windows to detect low resolution small objects. The performance of the proposed approach was experimentally evaluated, and the experimental results demonstrate it capable to extract link information from P&IDs of NPPs.
Matsuya, Yusuke; McMahon, S. J.*; Sato, Tatsuhiko; Butterworth, K. T.*; Saga, Ryo*; Date, Hiroyuki*; Prise, K. M.*
no journal, ,
Ionizing radiation has the potential to induce damage to DNA and subsequent late biological effects such as cell death. Amongst the types of DNA lesions, DNA double-strand breaks (DSBs) have been known as the principal damage form leading to cell death with a certain probability. To date, early DSB induction and the repair dynamics have been experimentally investigated, yet the optimum approach to directly evaluate the relationship between DSBs and cell death remain unclear. To solve this problem, we have developed a theoretical cell-killing model, the integrated microdosimetric-kinetic (IMK) model, which considers the responses of sub-lethal damage (corresponding to DSB) after irradiation and several biological factors, such as cell-cycle phase, oxygen pressure and intercellular communication. Using the IMK model, we have successfully reproduced experimental DSBs and survival data for various irradiation conditions and cell conditions. In this study, we introduce an overview of the IMK model. In particular, focusing on early DSBs yield and the repair kinetics, we present the latest estimation results for interpreting the cellular mechanisms of intercellular communication and oxygen effects. In the future, by developing an integrated package enabling to estimate cellular responses in the combination of the PHITS code and the IMK model, it will be expected to clarify the relationship between initial DNA damage and late biological effects, such as cell death and mutation.
