ESTRO 2023 - Abstract Book

S677

Monday 15 May 2023

ESTRO 2023

Overall, all models showed a good performance for targets and organs at risk (OAR). The figure shows the absolute differences in dose metrics for the predicted dose distributions compared to the GT doses. In general, larger model (HDUlarge) and larger training set s decreased the differences with GT. However, more data did not necessarily compensate for choosing HDUsmall instead of HDUlarge (see e.g. Rectum V75Gy, Femoral Heads D0.03cc and Dmean).

Conclusion Using a large set of fully-automatically generated prostate cancer plans with consistent trade-offs, increasing the training set from 56, 140 to 561 patients only resulted in small reductions in differences between deep learning dose predictions and ground truth. Network was more important than dataset for reduction of these differences. As HDUlarge was the maximum that fits our GPU-card (which is the largest currently available), use of less memory-demanding network architectures could be explored to further improve deep learning dose prediction quality.

Poster Discussion: Pelvic cancers

PD-0805 Inter-observer variation for national Danish contouring atlas on organs at risk in the pelvis

L. Poulsen 1 , J. Søndergaard 1 , E. Lorenzen 2 , R. Bahij 2 , L. Bentzen 3 , L. Dysager 2 , M. Grønbech 2 , B.M. Havelund 3 , S. Holst 1 , M. Klüver-Kristensen 2 , A.Ø. Knudsen 2 , C. Kronborg 4 , H. Lindberg 5 , C.V. Madsen 3 , L.S. Mouritsen 5 , C. Nyborg 2 , T.J. Nøttrup 6 , S.E. Petersen 7 , E. Serup-Hansen 5 , B. Weber 7 , K. Wind 8 , C.R. Hansen 9 1 Aalborg University Hospital, Department of Oncology, Aalborg, Denmark; 2 Odense University Hospital, Department of Oncology, Odense, Denmark; 3 Vejle Hospital, University Hospital of Southern Denmark, Department of Oncology, Vejle, Denmark; 4 Aarhus University Hospital, Danish Centre for Particle Therapy, Department of Clinical Medicine, Faculty of Health,, Aarhus, Denmark; 5 Copenhagen University Hospital - Herlev and Gentofte, Department of Oncology, Copenhagen, Denmark; 6 University of Copenhagen, Rigshospitalet, Department of Oncology, Section of Radiotherapy, Copenhagen, Denmark; 7 Aarhus University Hospital, Danish Centre for Particle Therapy, Aarhus, Denmark; 8 Aarhus University Hospital,