ESTRO 2025 - Abstract Book

S1330

Clinical - Lung

ESTRO 2025

associated with worse OS (Models 4–6). When the models were reanalyzed using physical doses instead of EQD2,3, the results were comparable (data not shown).

Conclusion: Higher radiotherapy doses to non-emphysematous lung regions compared to the whole lung predict poorer OS in NSCLC patients. While promising, these findings require further validation. If confirmed, they could guide future trials on functional lung-sparing radiotherapy, leveraging a simple and easily implementable image-based biomarker of emphysema to optimize treatment for NSCLC patients.

Keywords: lung dose, emphysema, NSCLC, OS,radiotherapy, FEV1

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Digital Poster SBRT for Solitary Pulmonary Nodule (SPN) with or without histological confirmation: long-term outcomes of a mono-institutional experience. Francesca Di Pressa 1,2 , Barbara Diletto 1 , Fabrizio Salvi 1 , Davide Allegri 3 , Giovanni Piero Frezza 1 , Silvia Magi 4 , Marcella Palombarini 4 , Silvia Ricci 4 , Raffaella Romagnoli 4 , Francesco Buia 5 , Giorgina Dalpiaz 6 , Marco Ferrari 7 , Ilaria Maggio 8 , Alessandra Musto 9 , Francesca Sperandi 10 , Antonella Baldissera 1 , Damiano Balestrini 1 , Selena Ciabatti 1 , Elisa Donini 1 , Ombretta Martelli 1 , Piero Candoli 7 , Antonio Maestri 8 , Piergiorgio Solli 11 , Andrea Ardizzoni 10,12 , Elisa D'Angelo 1 1 Department of Radiation Oncology, AUSL of Bologna, Bologna, Italy. 2 Department of Radiation Oncology, University Hospital of Modena, Modena, Italy. 3 Department of Public Health, Local Health Authority of Bologna, Bologna, Italy. 4 Physics unit, AUSL of Bologna, Bologna, Italy. 5 Cardio-Thoracic-Radiology Unit, Department of Cardio-Thoracic Vascular, IRCSS Ospedaliero-Universitaria S. Orsola, Bologna, Italy. 6 Radiology Department, AUSL of Bologna, Bologna, Italy. 7 Interventional Pulmonology Unit, IRCSS Ospedaliero-Universitaria S. Orsola, Bologna, Italy. 8 Department of Medical Oncology, AUSL of Bologna, Bologna, Italy. 9 Nuclear Medicine, IRCSS Ospedaliero Universitaria S. Orsola, Bologna, Italy. 10 Medical Oncology, IRCSS Ospedaliero-Universitaria S. Orsola, Bologna, Italy. 11 Division of Thoracic Surgery, IRCSS Ospedaliero-Universitaria S. Orsola, Bologna, Italy. 12 Department of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy Purpose/Objective: Stereotactic radiotherapy (SBRT) is the standard treatment for medically inoperable histologically assessed or not SPN, achieving high rates of in-field tumor control, but controversial results for regional and distant outcomes. A rigorous multidisciplinary selection of non histological confirmed SPN is crucial to avoid an overtreatment of benign nodules. Material/Methods: In this Ethics Committee approved monocentric retrospective study, patients treated with lung SBRT, from January 2014 to December 2023, with diagnosis of early-stage non–small-cell lung cancer (ES-NSCLC) or radiologically assessed by serial CT scan and 18F FDG PET-CT 1-2 , were enrolled. Surgery was excluded after multidisciplinary evaluation or refused by patients. Lung SBRT was performed according to international guidelines 3 . All patients underwent regular follow-up (FUP): toxicity data were recorded. Efficacy outcomes were assessed and compared between patients with or without histological confirmation. Results: A cohort of 343 patients with a median age of 78 years, treated by lung SBRT, was retrospectively analysed. Population and treatment characteristics are described in Table 1. Histological confirmation was available in 123 pts (35.8%).