ESTRO 2025 - Abstract Book

S1389

Clinical - Lung

ESTRO 2025

Conclusion: Doses to the SAN and the base of the heart correlate with RIHD in CRT patients, while doses to the area around the LV in CRT+ICI patients. This alteration in critical subregion doses indicates that the use of ICI may shift the radiosensitivity in cardiac subregions. While the 2–6% increased risk of RIHD per Gy seems modest, it is clinically significant as the SAN and LV can potentially be significantly spared with carefully optimized plans.

Keywords: NSCLC, radiotherapy, immunotherapy, cardiotoxicity

References: 1. Rengan R, et al. New Strategies in Non–Small Cell Lung Cancer: Improving Outcomes in Chemoradiotherapy for Locally Advanced Disease. Clin Cancer Res . 2011. 2. Antonia SJ, et al. Durvalumab after Chemoradiotherapy in Stage III Non–Small-Cell Lung Cancer. N Engl J Med . 2017. 3. Melosky B, Juergens R, McLeod D, et al. Immune checkpoint-inhibitors and chemoradiation in stage III unresectable non-small cell lung cancer. Lung Cancer . 2019. 4. Cho Y, Kim Y, et al. Lymphocyte dynamics during and after chemo-radiation correlate to dose and outcome in stage III NSCLC patients undergoing maintenance immunotherapy. Radiother Oncol . 2022

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Poster Discussion Real world clinical outcomes for early-stage lung cancer treated with single-fraction stereotactic ablative radiotherapy in Australia Jennifer Yeh 1 , Neil Wallace 1 , Nicholas Hardcastle 1,2 , Kevin Tu 1 , Michelle Ryan 1 , Nikki Plumridge 1 , Mark Shaw 1 , Michael MacManus 1,2 , Greg Wheeler 1 , Monique Youl 1 , Andrew Wirth 1 , Keelan Byrne 1 , Tim Spelman 3 , Shankar Siva 1,2 , Susan Harden 1,2 1 Department of Radiation Therapy, The Peter MacCallum Cancer Centre, Melbourne, Australia. 2 Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia. 3 Department of Health Services Research, The Peter MacCallum Cancer Centre, Melbourne, Australia Purpose/Objective: Our institution developed experience in delivering single-fraction stereotactic ablative radiotherapy (SF SABR) for lung metastases through the TROG 13.01 SAFRON II trial (1) and expanded the use to include people diagnosed with primary early-stage lung cancer during COVID-19, based on two phase II randomised trials (2,3). Whilst multi-