Figure 1.

Measured dose in culture plate versus distance from the sample stage for the 35 MeV proton beam produced at the Cyclotron at the Korea Cancer Center Hospital. Sample stage was located vertically to the direction of beam exposure and culture dishes were adhered closely onto the stage in the bottom in which cells were plated. The distance 0 was estimated the entrance point to the plastic plate on which cells were plated. Thus distance from the stage 4.5 mm within SOBP in highest LET should be enough to cover all cells plated in the area (5 × 5 cm; height × width of sample located within plates).