ESTRO 2025 - Abstract Book

S492

Clinical - Breast

ESTRO 2025

Conclusion: To our knowledge, this study is the first to systematically review high-quality clinical trial evidence of HFPMRT in the reconstruction setting. HFPMRT achieves equivalent tumor control outcomes to CFPMRT, while reducing acute toxicity in patients without reconstruction and maintaining comparable chest wall complication rates in patients with reconstruction.

Keywords: Post-Mastectomy Radiation Therapy, Reconstruction

1752

Digital Poster Pro(-ton) or Cons? Patient-reported motivators and barriers for participation in the DBCG Proton Trial. A qualitative research study Kristine Wiborg Høgsbjerg 1 , Anne Wilhøft Kristensen 2 , Mette Møller 3 , Else Maae 4 , Maja Vestmø Maraldo 5 , Louise Wickmann Matthiessen 6 , Sami Aziz-Jowad Al-Rawi 7 , Mette Holck Nielsen 8 , Cai Grau 2,9 , Birgitte Vrou Offersen 1,2 1 Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark. 2 Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark. 3 Department of Oncology, Aalborg University Hospital, Aalborg, Denmark. 4 Department of Oncology, Vejle Hospital, University of Southern Denmark, Vejle, Denmark. 5 Department of Oncology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. 6 Department of Oncology, Copenhagen University Hospital, Herlev, Copenhagen, Denmark. 7 Department of Oncology, Zealand University Hospital, Næstved, Denmark. 8 Department of Oncology, Odense University Hospital, Odense, Denmark. 9 Department of Oncology, Aarhus University Hospital, Aarhus, Denmark Purpose/Objective: Participation in clinical trials is critical to advancing oncological treatments, yet equitable trial access remains challenging. Ensuring diverse patient inclusion strengthens external validity and enhances the generalisability of trial outcomes[1]. However, barriers to trial participation persist, and the factors influencing patient enrolment are not fully understood [2]. This study investigates the motivators and barriers affecting participation in the DBCG Proton Trial (NCT04291378). By clarifying these factors, we aim to provide actionable insights to encourage broader recruitment in trials and promote equitable treatment opportunities for all eligible patients. Material/Methods: Candidates for the DBCG (Danish Breast Cancer Group) Proton Trial — a randomised controlled trial (RCT) comparing proton therapy and photon therapy in breast cancer patients with a mean heart dose ≥ 4 Gy and/or V17/20 lung ≥ 37% at initial treatment planning — were selected for interviews [3]. Participants were purposefully sampled to ensure the inclusion of one participant and one non-participant from each of the seven radiotherapy centres in Denmark. Qualitative interviews were conducted via telephone, transcribed, and systematically analysed using an inductive approach to identify key motivators and barriers to participation [4]. Results: A total of fourteen patients were interviewed. Key motivators for participation included (1) hope for reduced cardiovascular and pulmonary late effects, aligning with the trial’s primary endpoint; (2) access to enhanced and more frequent follow-up care; (3) contributing to research and knowledge advancement; (4) hope for improved anticancer effect; and (5) a sense of receiving a special or advanced treatment. Primary barriers to participation were identified as (1) geographical distance, leading to increased time commitment, reduced time with family and friends, and fatigue associated with prolonged treatment and transportation time; (2) changes to the scheduled treatment plan, creating uncertainty for the patient; (3) additional hospital visits; (4) challenges in the decision-making process, including limited opportunities for discussion with other patients; and (5) concerns regarding the experimental nature of the treatment.