Fig. 3
![Fig. 3](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13014-016-0642-6/MediaObjects/13014_2016_642_Fig3_HTML.gif)
Comparison between three model predictions, as reported in the legends, for RBE as a function of proton dose for (α/β) x of photons of 2 Gy (upper panels) and 10 Gy (lower panels) at 1(6.5) keV/μm as reported in the left (right) column, respectively. For the LEM, predictions for two values of D t are reported