ESTRO 2025 - Abstract Book

S476

Clinical - Breast

ESTRO 2025

Results: following the two waves of solicitation (March-2024 and April-2024), 94 responses were recorded, with 52 from Italian oncologists and 42 from Spain. Spanish oncologists are more inclined to include IMC irradiation whenever axillary involvement is present, regardless of the size of the breast tumor or its anatomical location, compared to the responses of Italian oncologists. Italian radiation oncologists take a more definitive stance when deliberating whether to consistently irradiate (“always”) or abstain (“never”), contrasting with their Spanish counterparts, who exhibit less distinct inclinations and tend to opt for the "sometimes" option more frequently.We did not observe significant differences regarding the definition of IMC, irradiation technique, total doses and fractionation, or the use of respiratory control techniques.

Conclusions: IMC radiotherapy indications remains controversial and differences exist between Italian and Spanish radiation oncologists.

Keywords: Internal mammary chain, international survey

1230

Mini-Oral Patient-reported locoregional and general biopsychopsocial late effects at more than 10 years after treatment for breast cancer Marie Louise Holm Milo 1,2 , Robert Zachariae 3,4 , Anders Bonde Jensen 5 , Mette Holck Nielsen 6 , Else Maae 7 , Maja Vestmø Maraldo 8 , Birgitte Vrou Offersen 4,9,10 1 Oncology, Aalborg University Hospital, 9000, Denmark. 2 Department of Medicine, Aalborg University, Aalborg, Denmark. 3 psychology and Behavioural Sciences, Aarhus University, Aarhus, Denmark. 4 Oncology Department, Aarhus University Hospital, Aarhus, Denmark. 5 Clinical Medicine, Aarhus University, Aarhus, Denmark. 6 Oncology Department, Odense University Hospital, Odense, Denmark. 7 Oncology Department, University of Southern Denmark, Vejle, Denmark. 8 Oncology Department, Copenhagen University Hospital University Hospital, Copenhagen, Denmark. 9 Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark. 10 Danish Center of Particle Therapy, Aarhus University Hospital, Aarhus, Denmark Purpose/Objective: The Danish Breast Cancer Group (DBCG) has developed an app-based set of questionnaires to prospectively collect patient reported outcome measures regarding socio-economy, therapy, therapy related morbidities, and a range of biopsychosocial late effects. The aim of the present study was to characterize the extent of self-reported long-term loco-regional and general biopsychosocial late effects in a large cohort of breast cancer (BC) survivors who had received radiation therapy (RT) more than 10 years previously. Material/Methods: Participants were BC patients included in two randomized trials: The DBCG HYPO trial (five versus three weeks RT) and the DBCG PBI trial (whole breast versus partial RT) [1,2]. Patients were treated 2009-2016 for a T1-2,N0 BC, with breast conserving surgery, RT, and systemic treatment according to DBCG guidelines. All patients received an email with a link to the questionnaire. BC recurrence or other malignancies were excluding criteria. The questionnaire covered locoregional and the most common biopsychosocial late effects, including pain, insomnia, fatigue, cognitive impairment, depression, and fear of cancer recurrence. Results: A total of 2083 BC survivors were eligible for inclusion. Of these, 355 were deregistered in the email system, and 1717 received the questionnaire. In all, 1053 survivors (61%) responded, 94 had BC recurrence or other primary cancer, and 117 did not complete the questionnaire, resulting in 842 (49%) completed responses. Responder median age was 73 years (52-91), 769 (91%) survivors were postmenopausal, and 305 (36%) had comorbidity with