ESTRO 2025 - Abstract Book

S594

Clinical - Breast

ESTRO 2025

3687

Digital Poster More than a number: investigating quality-of-life concerns in breast cancer radiation therapy decision making Madeline S Therrien 1 , Simone M.B. Mingels 2 , Rianne R.R. Fijten 2 , Olga C Damman 3 , Liesbeth J Boersma 1 1 Department of Radiation Oncology (MAASTRO), Maastricht University Medical Centre, GROW School for Oncology and Reproduction, Maastricht, Netherlands. 2 Clinical Data Science, Maastricht University, GROW School for Oncology and Reproduction, Maastricht, Netherlands. 3 Department of Public and Occupational Health, Amsterdam University Medical Centre, Amsterdam, Netherlands Purpose/Objective: Decisions about radiation therapy (RT) can be challenging for breast cancer patients (BCPs), especially when the treatment primarily reduces the risk of local recurrence but offers minimal survival benefit. In these cases, the potential long-term side effects make RT decisions highly preference-sensitive, highlighting the importance of shared decision-making (SDM). To support SDM, we previously developed a patient decision aid (PtDA) designed to provide tailored information about RT and its side effects, helping BCPs evaluate their treatment preferences. Our PtDA targets four patient groups, namely, those considering: (1) RT after breast-conserving surgery for ductal carcinoma in situ (DCIS), (2) RT for low-risk breast cancer, (3) post-mastectomy RT for intermediate-risk cases, and (4) an additional RT boost to the tumor bed. Research suggests that BCPs prioritize understanding how side effects impact quality of life over their statistical likelihood of occurrence [1]. Thus, the objective of this study was to qualitatively explore the impact of RT side effects on patients’ daily lives to refine and enhance our PtDA. Material/Methods: We conducted 14 semi-structured interviews with former BCPs who had undergone RT (whole- or partial-breast, with or without a boost) 6–36 months prior to the interviews. Purposive sampling ensured diversity in age, socioeconomic status, and self-reported side effect severity (mild, moderate, or severe). Interviews explored how RT side effects affected daily activities, including work, hobbies, independence, and household responsibilities. Transcripts were analyzed using deductive coding, with three interviews double-coded independently by a second coder to ensure reliability. Thematic analysis identified recurring themes in the data. Results: Thematic analysis revealed RT’s significant impact on quality of life. Locoregional effects included insecurity about breast appearance (n=6), pain or discomfort, such as pain with touch (n=4), constant discomfort (n=5), and reduced sports participation (n=3). Arm functionality limitations, such as restricted movement (n=7) and reduced strength (n=3), were also noted, along with skin irritation that limited sun exposure (n=3) and sports participation (n=1). General effects included fatigue affecting work (n=8), energy levels (n=4), sports (n=2), physical wellbeing (n=2), and emotional wellbeing (n=2), as well as concentration issues impacting work (n=4) and hobbies (n=2). Conclusion: This study provides qualitative insights into the real-world consequences of RT side effects on daily life, offering a nuanced perspective to enhance patient-centered breast cancer care. These findings will inform updates to our PtDA, expected to enhance its ability to support informed, preference-sensitive decisions for BCPs in the context of SDM.

Keywords: shared decision making, patient decision aid

References: [1] Roumen et al. Breast cancer patients’ most important quality of life themes for a radiotherapy decision aid. The Breast. 2022; 65: 8-14.