S331
Clinical - Breast
ESTRO 2026
Purpose/Objective: A large proportion of BCS incorporates oncoplastic breast surgery (OPBS) technique involving displacement or replacement procedures to improve cosmesis without compromising safety. However, limited information is available regarding the potential effect on adjuvant radiation treatment planning and the implications in terms of acute and late adverse events (AEs) related to radiotherapy (RT). The aim of this analysis is to evaluate oncological, aesthetic and functional results after monolateral (reshaping or replacement) or bilateral (mammoplasty with contralateral pexy or reduction) conserving strategies
in the context of RT Material/Methods:
Women with localized BC undergoing lumpectomy with immediate OPBS and RT within IRONY (Life after ONcoplastic surgery) prospective cohort were evaluated and provided informed consent (ethical statement n. PAR 13.23 OSS ComET CBM, ClinicalTrials.gov ID: NCT05842148).The associations between the type of surgery (monolateral, ML vs bilateral, BL), clinicopathological factors (age, invasive tumor size, nuclear grade, nodal involvement, molecular subtypes), RT data (boost, occurrence of AEs) and satisfaction parameters were examined. For hypothesis testing, the two-tailed t-test (for continuous variables) and chi-squared test (for categorical variables) were applied. Patients assessed quality of life after completion of surgery and adjuvant RT using a questionnaire based on the following criteria: psychological wellness with social functioning, physical discomfort, and RT AEs.Radiotherapy was delivered with VMAT technique to the total dose of 40.05Gy (2.67 Gy/day) with or without boost (simultaneous or sequential). CTCAE v.5.0 was used for AEs. Results: 175 patients were analyzed. Patients characteristics were shown in Table 1. Multifocality (p = 0.034), multicentricity (p = 0.002) and resection volume (p = <0.001) were higher in BL group. Most patients achieved negative resection margins (98.9% and 97.6% in ML and BL groups, respectively). There was a comparable re-excision rate for positive margins (p = NS). Surgical complications were not different between the two groups. Radiotherapy related AEs were mainly represented by skin dermatitis which occurred in 51.2%, with only 2 patients (1.14%) experiencing grade 2 dermatitis. No differences were found between patients undergoing ML and BL OPBS, despite the higher volume of breast CTV (p=0.003) and boost CTV (p=0.049) of the BL group. Quality of life did not differ between the two groups (p=NS). See Table 2 for details.
Conclusion: OPBS demonstrated acceptable acute skin toxicity. Bilateral techniques, despite larger treatment volumes, were not linked to higher dermatitis rates, likely benefiting from the tissue remodeling achieved through pexy and reduction procedures. References: - Keywords: breast cancer, oncoplastic surgery, radiotherapy Pathological complete response and postoperative radiation therapy after primary systemic therapy: preliminary results from ReSTORE study Marianna Valzano 1 , Liat Mizrahi 2 , Rinat Bernstein Molho 3,2 , Carlotta Becherini 1 , Luca Visani 1 , Giulia Cesari 1 , Michela Carracino 1 , Ben Boursi 3,2 , Icro Meattini 1 , Orit Kaidar-Person 3,2 1 Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence University Hospital, Florence, Italy. 2 Gray Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel. 3 Breast Cancer Radiation Therapy Unit, Sheba Medical Center, Ramat Gan, Israel Poster Discussion 4652
Made with FlippingBook - Share PDF online