Figure 2.

Examples of setup error effects on dose-volume histograms (DVH). For the example patient in Figure 1, CTV and chiasm DVH of (a) carbon ion and (b) proton treatment plans using two different planning approaches (mcLR and mcROB) as planned and re-computed in presence of positioning errors. In color the original plan and two setup errors, of 1 mm (0,+,-) and 2 mm (0,0,-), shown in Figure 1. In grey all other simulated setup errors. In the shifts, + and - indicate the direction of (equal) non-zero components. Abbreviations: CTV – clinical target volume, LR – lateral-opposed beam setup, ROB – robust beam setup, mc – multiple-field modulation.