ESTRO 2022 - Abstract Book

S1389

Abstract book

ESTRO 2022

RMSE in the organ’s region=15.4 HU, DSC=0.98 and the 95th percentile Hausdorff distance=2 mm. Fig.2 shows a visual comparison between the ground truth and the prototype constructed Mid-P.

Conclusion The generated mathematical phantom can be used by developers to test the geometric accuracy of the constructed Mid-P CT, it can also be used for commissioning the Mid-P applications when they are commercially available. The results of the evaluated prototype showed excellent matching with the ground truth.

PO-1604 Weekly dosimetric evaluation of CBCT-based synthetic CTs for proton therapy of head & neck patients

R. de Koster 1 , A. Thummerer 1 , G. Guterres Marmitt 1 , D. Scandurra 1 , H. Langendijk 1 , S. Both 1

1 University Medical Center Groningen, University of Groningen, Department of Radiation Oncology, Groningen, The Netherlands Purpose or Objective In proton therapy it is common practice to acquire weekly verification CTs to monitor treatment progress and recalculate treatment plans on updated patient anatomy. For daily adaptive proton therapy workflows however, repurposing in-room images such as cone-beam CTs (CBCT), is more suitable since it is not adding to the clinical workload and does not cause