@article{oai:repo.qst.go.jp:00043004,
 author = {Kagawa, Kazufumi and Murakami, Masao and Hishikawa, Yoshio and Abe, Mitsuyuki and Akagi, Takashi and Yanou, Toshihiro and Kagiya, Gou and Furusawa, Yoshiya and Ando, Koichi and Nojima, Kumie and Aoki, Mizuho and Kanai, Tatsuaki and 香川 一史 and 村上 昌雄 and 菱川 良夫 and 阿部 光幸 and 赤城 卓 and 鍵谷 豪 and 古澤 佳也 and 安藤 興一 and 野島 久美恵 and 青木 瑞穂 and 金井 達明},
 journal = {International Journal of Radiation Oncology Biology Physics},
 month = {Mar},
 note = {Purpose: To assess the biologic effects of proton and carbon ion beams before clinical use.
Methods and Materials: Cultured cells from human salivary gland cancer (HSG cells) were irradiated at 5 points along a 190 MeV per nucleon proton and a 320 MeV per nucleon carbon ion beam, with Bragg peaks modulated to 6 cm widths. A linac 4 MV X-ray was used as a reference. Relative biologic effectiveness (RBE) values at each point were calculated from survival curves. Cells were also irradiated in a cell-stack phantom to identify that localized cell deaths were observed at predefined depth. Total body irradiation of C3H/He mice was performed, and the number of regenerating crypts per jejunal section was compared to calculate intestinal RBE values. For carbon ion and referential 4 MV X-ray beams, mouse right legs were irradiated by four-fractional treatment and followed up for skin reaction scoring. 
Results: RBE values calculated from cell survival curves at the dose that would reduce cell survival to 10% (D10) ranged from 1.01 to 1.05 for protons and from 1.23 to 2.56 for carbon ions. The cell-stack phantom irradiation revealed localized cell deaths at predefined depth. The intestinal RBE values ranged from 1.01 to 1.08 for protons and from 1.15 to 1.88 for carbon ions. The skin RBE value was 2.16 at C320/6 cm spread-out Bragg peak (SOBP) center.
Conclusion: The radiobiologic measurements of proton and carbon ion beams at Hyogo Ion Beam Medical Center are consistent with previous reports using proton beams in clinical settings and carbon ion beams with similar linear energy transfer (LET) values.},
 pages = {928--938},
 title = {Preclinical biological assessment of proton and carbon ion beams at Hyogo Ion Beam Medical Center},
 volume = {54},
 year = {2002}
}