ESTRO 2021 Abstract Book

S22

ESTRO 2021

Conclusion 4DRO provided superior robustness for target coverage in some patients. However, 3DRO demands less workload, offers better healthy lung sparing and yields similar interplay effect reduction when combined with rescanning. PH-0047 CTV and OAR robustness of clinical neuro IMPT: dosimetric impact of the DUPROTON robustness protocol J. Rojo Santiago 1,2 , S.J. Habraken 1,2 , D. Lathouwers 3 , A. Méndez Romero 1,2 , Z. Perkó 3 , M.S. Hoogeman 1,2 1 Erasmus MC Cancer Institute, Radiotherapy, Rotterdam, The Netherlands; 2 HollandPTC, Medical Physics & Informatics, Delft, The Netherlands; 3 Delft University of Technology, Radiation Science & Technology, Delft, The Netherlands

Purpose or Objective In intensity-modulated proton therapy (IMPT), the clinical assessment of robust dose in organs-at-risk (OARs) is