Fig. 8

RBE at 10% cell survival for human normal tissue cells irradiated with carbon ions. The results are obtained using Eq. 35. In the high-LET region, the RBE becomes inversely proportional to LET, and the absolute values of RBE depend on the number of ions that traverse the cell nucleus. The values of \(N_{\text {ion}}\) corresponding to different segments of the calculated curve are indicated. The dashed line is a guide to the eye connecting median points of the hyperbolas. Symbols depict experimental data from Suzuki et al. (1996), Suzuki (2000), Tsuruoka (2005) and Belli (2008)