ESTRO 2025 - Abstract Book

S630

Clinical - Breast

ESTRO 2025

patient-decision aid for clinical trials. More doctors focus on trial including being aware of trial and how to better inform the patient appears relevant. Significant disparities in inclusion highlight the importance of improved patient awareness regarding trial benefits. Enhanced information could reduce non-inclusion rates, supporting equitable BC care in Denmark.

Keywords: Radiotheraphy, Disparity, Clinical Trials

References: 1) Cancerregistret. Nye Kræfttilfælde i Danmark 2018. Sundhedsdatastyrelsen.

2) Ejlertsen B et al. Forty years of DBCG trials. Acta Oncol. 2018;57(1):3-12. doi: 10.1080/0284186X.2017.1408962. 3) Kerba M et al. Defining the need for breast cancer radiotherapy: a benchmarking approach. Clin Oncol. 2007;19:481-9. doi: 10.1016/j.clon.2007.03.013. 4) Shack L et al. Radiotherapy need and utilization in breast, cervix, lung, prostate, and rectum cancers. Radiother Oncol. 2017;122:152-8. 5) MacKenzie P et al. Age and comorbidity-adjusted optimal radiotherapy rates in breast cancer. J Geriatr Oncol. 2022;13:844-9. 6) Round CE et al. Radiotherapy demand in England 2006-2020. Clin Oncol. 2013;25:522-30

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Digital Poster Efficacy, safety and benefit of lymph node irradiation with FAST-forward Nerea Ugarte Ruiz de Aguirre, Francisco de Paula Titos Sánchez, Carolina Ortiz Bautista, Magdalena Márquez García Salazar, Carlos Miguez Sánchez, David Muñoz Carmona Radiation oncology, Hospital Universitario Virgen Macarena, Sevilla, Spain Purpose/Objective: After the publication of the FAST-Forward (FF) trial, this scheme has become part of the standard of care in breast cancer, allowing to reduce the treatment time to a third, maintaining a good disease control without increasing adverse effects. Currently, there are no clinical trial results on the use of these regimens when treating de nodal areas, which leads to patients who need it having to pursue longer regimens. Our hypothesis is that treating the nodal areas with this fractionation schedule achieves a similar control without increasing toxicity. In this abstract, we present you the outcomes of the first patients with FF nodal treatment treated at our center. Material/Methods: Retrospective observational single-center study that compares patients treated during 2020 at the Hospital Virgen Macarena with the FF regimen, including or not including the nodal areas. Results: A total of 123 patients have been included in this analysis, of whom 28 (22.8%) received nodal irradiation in addition to breast irradiation, administering a dose of: 26 Gy in 5 daily fractions. Among the patients with treated nodal areas, 85.7% received treatment to levels III and IV, 10.7% to levels I-IV, and 7.1% exclusively to levels I-II. No patients with internal mammary involvement were treated. At the time of analysis, with a median followup of 44.3 months, no patient presented locoregional recurrence. Three patients presented distant failure, with brain, liver and lung involvement, of which none belonged to the group of lymph node treatment. We recorded 10 deaths, of which only 2 were due to breast cancer. Regarding the adverse effects, no differences were observed in acute locoregional toxicity (41.5% vs. 46.4%, p = 0.67) and chronic toxicity (10.1% vs. 18.5%, p = 0.31) between groups. The rates of lymphedema, radiodermatitis,