ESTRO 2025 - Abstract Book

S1416

Clinical - Lung

ESTRO 2025

Conclusion: This study will address the characterization of NSCLC by offline 3T MRI. It will also address the value of thoracic DWI for defining morphological and functional biomarkers for possible boost strategies in oART, early risk stratification and for prognosis assessment of NSCLC.

Keywords: adaptive radiotherapy, MRI, DWI

3872

Digital Poster Serendipitous discovery of a novel pathophysiology for pulmonary hemorrhage following central pulmonary radiotherapy Andrew J Hope 1,2 , Meredith E Giuliani 1,2 , Benjamin H Lok 1,2 , Andrea Bezjak 1,2 , B.C. John Cho 1,2 , Alex Sun 1,2 , Patricia E Lindsay 1,2 1 Radiation Oncology, University of Toronto, Toronto, Canada. 2 Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Canada Purpose/Objective: Fatal pulmonary hemorrhage following radiation for thoracic malignancies has been a rare but recognized toxicity following radiation 1–3 . Vascular and bronchial dose limits are employed to reduce the risk of this complication and dose escalation remains limited by central toxicity. However, due to the rarity of this event and poor understanding of the pathophysiology of pulmonary hemorrhage, patients with central lung tumors remain at risk. Material/Methods: All treated patients who suffer high grade toxicity are carefully reviewed at our tertiary referral center. In 2024, a patient unfortunately experienced a G5 pulmonary hemorrhage following central lung tumor treatment with 60Gy/8#. Coincidentally, the patient had follow-up computed tomography performed hours before the toxicity