Fig. 5.
Excess relative risk (ERR) of a secondary malignant neoplasm developing after intensity-modulated X-ray therapy (IMRT) and proton therapy for medium patient for various risk models. The quantity RRR denotes the ratio of the ERR from proton therapy to the ERR from IMRT. Risk models include linear–no threshold (LNT); linear–exponential rolling off at 10 Sv [LEXP(10)]; linear–plateau rolling off at 10 Sv [LPLAT(10)]; linear–exponential rolling off at 40 Sv [LEXP(40)]; and linear–plateau rolling off at 40 Sv [LPLAT(40)].