ESTRO 2025 - Abstract Book

S4335

RTT - Treatment planning, OAR and target definitions

ESTRO 2025

Conclusion: Online MR-adaptive radiotherapy for cervical cancer allows for improved sparing of OARs compared to LOP.

Keywords: MRgRT, Adaptive RT, dosimetry

1348

Proffered Paper Radiotherapy treatment strategy for prostate cancer with lymph node involvement Amanda Östensson, Josefine Grefve, Camilla Thellenberg-Karlsson, Karin Söderkvist, Magnus Karlsson, Tufve Nyholm, Joakim Jonsson Department of Diagnostics and Intervention, Radiation Physics, Umeå University, Umeå, Sweden Purpose/Objective: In prostate cancer radiotherapy, gold fiducial markers are typically used for accurate patient positioning. However, treatment planning for high-risk patients with potential lymph node involvement is complicated due to independent target motions. This necessitates large margins, applied either to the prostate or lymph nodes, based on positioning using gold fiducial markers or bone anatomy.