ESTRO 2025 - Abstract Book

S1467

Clinical – Mixed sites & palliation

ESTRO 2025

categorized as “non - repeated” had an increased CR probability (43.7%).In the final group, "Uniformity" values below 0.28 raised the CR probability to 62.5% (compared to a CR probability of 34.0%), with the probability reaching 100% for lesions having a "SurfaceVolumeRatio" greater than 0.37. Conclusion: This study suggests that radiomic features extracted from pretreatment planning CT scans may be a valuable tool for predicting complete response in patients with liver oligometastases treated with SBRT.

Keywords: SBRT, Radiomics, Liver metastases

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Proffered Paper Quality-of-life and in-depth pain-response after stereotactic ablative radiotherapy of oligometastatic bone metastases in the BONY-M trial Nicklas Juel Spindler 1 , Sebastian Moretto Krog 1 , Olfred Hansen 2,3 , Tine Bjørn Nielsen 2 , Morten Hiul Suppli 4 , Mirjana Josipovic 4,5 , Laurids Østergaard Poulsen 6 , Fatma Gaard-Petersen 1 , Hella Maria Brøgger Sand 6 , Tatiana Mikhailovna Abramova 7 , Marie Johansen 7 , Josefine Staahl Kornerup 8 , Mirjam Delange Alasker 8 , Mette Van Overeem Felter 1 , Rikke Løvendahl Eefsen 1 , Kasper Madsen 1 , Eva Serup-Hansen 1 , Poul Geertsen 1 , Ivan Richter Vogelius 4,5 , Claus Preibisch Behrens 1,9 , Gitte Fredberg Persson 1,5 1 Department of Oncology, Copenhagen University Hospital - Herlev and Gentofte, Herlev, Denmark. 2 Department of Oncology, Odense University Hospital, Odense, Denmark. 3 Department of Clinical Research, University of Southern Denmark, Odense, Denmark. 4 Department of Oncology, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark. 5 Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark. 6 Department of Oncology, Aalborg University Hospital, Aalborg, Denmark. 7 Department of Radiotherapy, Clinic of Oncology, Ålesund Hospital, Ålesund, Norway. 8 Department of Radiotherapy, Clinic of Oncology, St. Olavs University Hospital, Trondheim, Norway. 9 Department of Health Technology, Technical University of Denmark, Lyngby, Denmark Purpose/Objective: Local-metastases-directed stereotactic ablative body radiotherapy (SABR) is increasingly implemented to control oligometastatic disease (OMD). Patients with OMD may be asymptomatic, why severe toxicity impacting quality of life (QoL) should be avoided. The BONY-M trial was a multicenter phase II trial evaluated the efficacy and safety of SBRT of bony oligometastases (NCT05101824). In this analysis, we present patient-reported QoL within 52 weeks after treatment. Material/Methods: Six centers from Denmark and Norway enrolled 67 patients with 78 bone metastases to SABR with 30 or 37.5 Gy in 3 fractions. QoL (EuroQoL EQ-5D-5L), pain intensity and response (numeric pain rating scale, NPRS), and analgetic use (per the International Consensus Pain Response Endpoints, ICPRE) were assessed at baseline, 2, 12, 24, 36, and 52 weeks after SABR. Changes in the EQ-5D-5L index and visual analog scale (VAS) score were analyzed using a linear mixed-effects model with random intercepts and a Tobit censored regression model. Pain response was evaluated for patients with baseline NPRS ≥ 2 and asymptomatic patients were defined by a NPRS score of 0 -1. A post-hoc analysis comparing baseline NPRS to progression free survival was made using the cox proportional hazards method and log-rank test. A multivariate analysis including the covariates of histology and OMD group was similarly performed.