Fig. 4
Each boxplot contains differences in mean or near-maximum (1%) values between biological effectiveness guided plans and dose-only optimized plans in critical organs at risk for all patients. Absolute differences in constant (D1.1, first row) and variable RBE-weighted dose (DRBE, third row) and dose-averaged linear energy transfer (LETd, second row) are shown. Statistically significant differences (p < 0.05) are marked with an arterisk. Abbreviations: TEopt: track-end optimization, LETopt: dose-averaged linear energy transfer (LETd) optimization with dose threshold, DDopt: Dirty dose optimization, DRBEopt: variable RBE-weighted dose optimization