- 著者
- Akiko UZAWA Koichi ANDO Yoshiya FURUSAWA Go KAGIYA Hiroshi FUJI Masaharu HATA Takeji SAKAE Toshiyuki TERUNUMA Michael SCHOLZ Sylvia RITTER Peter PESCHKE
- 出版者
- Journal of Radiation Research 編集委員会
- 雑誌
- Journal of Radiation Research (ISSN:04493060)
- 巻号頁・発行日
- vol.48, no.Suppl.A, pp.A75-A80, 2007 (Released:2007-05-19)
- 参考文献数
- 15
- 被引用文献数
- 20
Charged particle therapy depends on biological information for the dose prescription. Relative biological effectiveness or RBE for this requirement could basically be provided by experimental data. As RBE values of protons and carbon ions depend on several factors such as cell/tissue type, biological endpoint, dose and fractionation schedule, a single RBE value could not deal with all different radiosensitivities. However, any biological model with accurate reproducibility is useful for comparing biological effectiveness between different facilities. We used mouse gut crypt survivals as endpoint, and compared the cell killing efficiency of proton beams at three Japanese facilities. Three Linac X-ray machines with 4 and 6 MeV were used as reference beams, and there was only a small variation (coefficient of variance < 2%) in biological effectiveness among them. The RBE values of protons relative to Linac X-rays ranged from 1.0 to 1.11 at the middle of a 6-cm SOBP (spread-out Bragg peak) and from 0.96 to 1.01 at the entrance plateau. The coefficient of variance for protons ranged between 4.0 and 5.1%. The biological comparison of carbon ions showed fairly good agreement in that the difference in biological effectiveness between NIRS/HIMAC and GSI/SIS was 1% for three positions within the 6-cm SOBP. The coefficient of variance was < 1.7, < 0.6 and < 1.6% for proximal, middle and distal SOBP, respectively. We conclude that the inter-institutional variation of biological effectiveness is smaller for carbon ions than protons, and that beam-spreading methods of carbon ions do not critically influence gut crypt survival.
- 著者
- Manami MONOBE Akiko UZAWA Makiko HINO Koichi ANDO Shuji KOJIMA
- 出版者
- Journal of Radiation Research 編集委員会
- 雑誌
- Journal of Radiation Research (ISSN:04493060)
- 巻号頁・発行日
- vol.46, no.1, pp.117-121, 2005 (Released:2005-04-01)
- 参考文献数
- 23
- 被引用文献数
- 21
Human whole-blood was exposed to 137Cs γ-rays or 50 keV/μm carbon ions in the presence or absence of glycine betaine, a beer component in vitro. The dicentrics of chromosome aberrations in human lymphocytes were significantly (p < 0.05) reduced by glycine betaine after irradiation with 4 Gy of either γ-rays or carbon ions. The maximum protection by glycine betaine for γ-rays or carbon ions was 37% and 20%, respectively. C3H/He female mice, aged 14 weeks, received an i.p. injection of glycine betaine 15 min before whole-body irradiation with γ-rays or 50 keV/μm carbon ions. Glycine betaine significantly (p < 0.05) increased the percent survival of irradiated mice with either γ-rays or carbon ions. In conclusion, glycine betaine is a potent protector against damages caused by low- and high-LET radiation.