Abstract
Biological effectiveness was compared among accelerated carbon, proton beam and gamma-rays. 290MeV/n carbon and 70MeV proton beam was generated by HIMAC and NIRS930 respectively. Biological effectiveness was calculated from cell survival obtained in special cell culture container, Opticells. Cell survival fraction was determined approximately each 2mm thickness till particle beam reaches its bragg peak. Dose was calculated from each data points and re-constitute the regular cell survival curves. CHO wild-type cells showed non-scattered straight line of survival curves as X-rays and gamma-rays. On the other hand, survival fraction after carbon ion exposure was not depending on dose of radiation. This result shows greater relative biological effectiveness for carbon beam but not for proton beam.
