ESTRO 2025 - Abstract Book

S4421

Late-breaking abstracts

ESTRO 2025

4.

Supplement to 5.

5. Automated (AI) segmentation of pelvic bone substructures and clinical evaluation in the DACG II trial - bone sparing radiotherapy for anal cancer. Kronborg CJS et al. IMACC Rome, Italy 2023.

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Proffered Paper PORTEC-4a; an international randomised trial of molecular profile-based adjuvant treatment for women with high-intermediate risk endometrial cancer Anne Sophie V.M. van den Heerik 1 , Nanda Horeweg 1 , Marie A.D. Haverkort 2 , Nienke Kuijsters 3 , Stefan Kommoss 4 , Friederike L.A. Koppe 5 , Marlies E. Nowee 6 , Henrike Westerveld 7,8 , Marianne A.A. De Jong 9 , David Cibula 10 , Jeltsje S. Cnossen 11 , Jan Willem M. Mens 8 , Jannet C. Beukema 12 , Cyrus Chargari 13 , Charles Gillham 14 , Ina M. Jurgenliemk-Schulz 15 , Katrien Vandecasteele 16 , Hans W. Nijman 17 , Bastiaan G. Wortman 1,11 , Stephanie M. De Boer 1 , Karen W. Verhoeven-Adema 18 , Remi A. Nout 1,8 , Hein Putter 19 , Tjalling Bosse 20 , Carien L. Creutzberg 1 1 Radiation Oncology, Leiden University Medical Center, Leiden, Netherlands. 2 Radiation Oncology, Radiotherapiegroep, Arnhem, Netherlands. 3 Radiation Oncology, Maastro, Maastricht, Netherlands. 4 Women's health, University of Tübingen, Tübingen, Germany. 5 Radiation Oncology, Institute Verbeeten, Tilburg, Netherlands. 6 Radiotherapy, Netherlands Cancer Institute, Amsterdam, Netherlands. 7 Radiation Oncology, Amsterdam University Medical Centers, Amsterdam, Netherlands. 8 Radiotherapy, Erasmus MC - Cancer Institute, Rotterdam, Netherlands. 9 Radiotherapy, Radiotherapeutisch Instituut Friesland, Leeuwarden, Netherlands. 10 Gynaecology, Obstetrics and Neonatology, General University Hospital Prague, First Medical Faculty of the Charles University, Prague, Czech Republic. 11 Radiotherapy, Catharina Hospital, Eindhoven, Netherlands. 12 Radiotherapy, University Medical Center Groningen, Groningen, Netherlands. 13 Radiotherapy, Institut Gustave Roussy, Villejuif, France. 14 Radiation Oncology, St. Luke’s Hospital, Dublin, Ireland. 15 Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands. 16 Radiation Oncology, Ghent University, Ghent, Belgium. 17 Gynecology, University Medical Center Groningen, Groningen, Netherlands. 18 IKNL, Netherlands Comprehensive Cancer Organisation, Utrecht, Netherlands. 19 Medical Statistics, Leiden University Medical Center, Leiden, Netherlands. 20 Pathology, Leiden University Medical Center, Leiden, Netherlands Purpose/Objective Standard adjuvant treatment for women with high-intermediate risk endometrial cancer (HIR-EC) is vaginal brachytherapy (VBT), fig 1A. Treating all these patients with VBT could be overtreatment since effective salvage treatments are available in radiation-naïve patients. Molecular analysis of the previous PORTEC-trials led to the development of a molecular-integrated-profile, combining the molecular classification with substantial lymph vascular-space-invasion, L1CAM-overexpression, and CTNNB1-exon-3-mutation into favourable, intermediate, and unfavourable profiles. The PORTEC-4a trial was designed to investigate non-inferiority of individually tailored adjuvant treatment to reduce over- and undertreatment for optimal locoregional control and quality-of life. Material/Methods The PORTEC-4a is an international randomised trial comparing adjuvant treatment based on the molecular integrated-profile to standard VBT in HIR-EC, figure 1A. After randomisation, tumour tissues were molecularly profiled, figure 1B. In the experimental arm the results were shared with the treating physician. Primary endpoint was vaginal recurrence (VR) as first event. Key secondary endpoints included cumulative incidence of pelvic (PR), locoregional recurrence (LRR), distant metastasis (DM), recurrence-free survival (RFS) and overall survival (OS).