Biological Response of Chinese Hamster B14-150 Cells to Sequential Combined Exposure to Protons and 12C Ions

Proton and ion radiation therapy, when used both as single radiation and in mixed radiation mode, have a number of advantages over the conventional γ-therapy that are determined by physical characteristics of accelerated particles. The paper presents the results of an in vitro study of the effectiveness of sequential exposures of Chinese hamster tumor cells B14-150 to proton (p) and 12C ion beams. We used 4 irradiation schemes differing by the sequence of exposure and the contribution of each radiation to the total dose. Synergism was shown for 12C ions dose contribution of 45% (taking into account the coefficient of relative biological efficiency) and the sequence 12C→p.