fig4

Figure 4. Proposed approach to protect normal tissue by stimulating radioadaptive responses. Horizontal X-ray beam delivers a priming dose to protect OAR (blue), but not the tumor (red) from subsequent, high doses delivered with a vertical beam(A); low priming dose of charged particles (left) protect OAR (blue) from subsequent high doses (right) (B). With charged particles, priming and therapeutic doses can be delivered along the same beamline since particles stop at predetermined depths. Charged particles also protect normal tissue distal to the tumor (larger blue section). OAR: organs at risk