ESTRO 2024 - Abstract Book

S4278

Physics - Intra-fraction motion management and real-time adaptive radiotherapy

ESTRO 2024

This study shows substantial reductions in longitudinal motion and ITV volume with EG. Average treatment time is clinically acceptable and the technique is straightforward for most patients. However, there is a sub-set of patients in whom treatment is long and breathing is more variable. In these patients coaching/breathing instructions can help. Despite individual challenges, the technique may still be preferred to free-breathing, for example, if it achieves better sparing of an important organ-at-risk, and easier set-up registration due to sharper tumor boundaries. Our experience is consistent with that of others [4]. Further work is ongoing to investigate the dosimetric impact of exhale gated lung SBRT.

Keywords: Expiration gating, Lung SBRT, motion management

References:

1. Senthi S, Lagerwaard FJ, Haasbeek CJA, Slotman BJ, Senan S. Patterns of disease recurrence after stereotactic ablative radiotherapy for early stage non-small-cell lung cancer: a retrospective analysis. Lancet Oncol 2012;13(8):802 9 2. Hurkmans CW, Cuijpers JP, Lagerwaard FJ, Widder J, Heide van der UA, Schuring D, Senan S. Recommendations for implementing stereotactic radiotherapy in peripheral stage IA non-small cell lung cancer: report from the quality assurance working party of the randomized phase III ROSEL study. Radiat Oncol 2009;4:1 3. Hazelaar C, Dahele M, Mostafavi H, Weide van der L, Slotman BJ, Verbakel WFAR. Markerless positional verification using template matching and triangulation of kV images acquired during irradiation for lung tumors trested in breath hold. Phys Med Biol 2018;63(11):115005 4. Remmerts de Vries IF, Dahele M, Mostafavi H, Slotman BJ, Verbakel WFAR. Markerless 3D tumor tracking during single-fraction free-breathing 10MV flatterning-filter-free sereotactic lung radiotherapy. Radiother Oncol 2021;164:6 12

5. Meyers SM, Kisling K, Atwood TF, Ray X. A standardized workflow for respiratory-gated motion management. J Appl Clin Med Phys 2022;23(8):e13705

1618

Poster Discussion

Setup validation for respiratory gated liver proton therapy by detailed analysis of CBCT projections

Esben S Worm 1 , Saber Nankali 2 , Jakob B Thomsen 2 , Line B Stick 2 , Morten Høyer 2 , Britta Weber 2 , Hanna R Mortensen 2 , Per R Poulsen 2 1 Aarhus University Hospital, Department of Oncology, Aarhus, Denmark. 2 Aarhus University Hospital, Danish Centre for Particle Therapy, Aarhus, Denmark

Purpose/Objective: