Fig. 1
Objectives and workflow to create treatment plans based on dose-only and biological effectiveness guided optimization with the aim to reduce variable relative biological effectiveness (RBE) weighted dose (DRBE) to critical organs at risk (OAR) while maintaining target coverage, robustness, dose homogeneity and conformity. A) Clinically acceptable reference plan using only objectives for absorbed dose, thus D1.1 (DOSEopt). B) Maintaining the same DOSEopt objectives and adding objectives for one of the four different biological effectiveness guided (BG) optimization strategies. Abbreviations: ROI: region of interest, DVH: dose-volume histogram, PTV: planning target volume, TE: track-ends, LETd: dose-averaged linear energy transfer, DD: dirty dose, DRBE: variable RBE-weighted dose, opt: optimization