ESTRO 2021 Abstract Book

S221

ESTRO 2021

Results The DEA score range for the full dataset of clinically acceptable (treated) plans was from 0.56 to 1.00 with an average of 0.79. Nine plans had a score of 1.00 and defined the best practice frontier. The results of the five DEA-guided replanned cases are shown in Table 1. Four were considered improved with two rated as a clear improvement. One was not preferred to the original plan due to the dose to some OAR. The plans that were most improved showed the largest changes to DEA score.

Conclusion Applying the DEA model to a dataset of prior clinically approved plans resulted in DEA identifying a frontier of best-practice plans. This best-practice frontier can then be used to successfully guide the planning process.

OC-0312 CT-less 3D image guidance for high-precision small animal particle irradiation M. Boucsein 1,4 , J. Müller 2,3 , T. Suckert 2,3,5 , E. Beyreuther 2,6 , M. Alber 4,7,8 , A. Dietrich 2,5 , A. Lühr 2,3,5,9 , E. Bahn 1,4,7,8 1 German Cancer Research Center DKFZ, Clinical Cooperation Unit Radiation Oncology, Heidelberg, Germany; 2 Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz- Zentrum Dresden-Rossendorf, OncoRay - National Center for Radiation Research in Oncology, Dresden, Germany; 3 Institute of Radiooncology - OncoRay, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; 4 Heidelberg University Hospital, Radiation Oncology, Heidelberg, Germany; 5 German Cancer Consortium (DKTK), Partner Site Dresden, Dresden, Germany; 6 Institute of Radiation Physics, Helmholtz - Zentrum