ESTRO 2025 - Abstract Book

S3233

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

ESTRO 2025

Conclusion: With our measurement setup the gating of the MRIdian MR-linac works as expected for the tracking margins of 2 mm, 3 mm and 4 mm. For a faster moving target, the gating accuracy decreases, but the performance is still acceptable. For future studies, faster target movement and different movement patterns could be tested.

Keywords: MR-guided Radiotherapy (MRgRT)

References: [1] Ng J et al., MRI-LINAC: A transformative technology in radiation oncology. Front Oncol. Vol. 13 1117874 2023 Jan. doi: 10.3389/fonc.2023.1117874. [2] Chuong MD et al., Stereotactic MR-guided on-table adaptive radiation therapy (SMART) for borderline resectable and locally advanced pancreatic cancer: A multi-center, open-label phase 2 study. Radiotherapy and Oncology. Vol. 191 110064 2024 Feb. doi: 10.1016/j.radonc.2023.110064.

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Digital Poster Reproducibility and stability of DIBH and free breath in breast radiotherapy based on real-time 3 dimensional optical surface imaging system Junxiang Wu 1 , Bin Tang 2 , Lucia Clara Orlandini 1 1 Radiation Oncology, Sichuan Cancer hospital, Chengdu, China. 2 Radiation Oncology, Sichuan Cancer Hospital, Chengdu, China Purpose/Objective: The aim of this study was to evaluate the inter-fraction reproducibility and intra-fraction stability of breast radiotherapy using voluntary deep-inspiration breath hold (DIBH) and free breathing (FB) based on an optical surface imaging system (OSIS).