ESTRO 2025 - Abstract Book

S424

Clinical - Breast

ESTRO 2025

characterized by progressive skin induration, pain, and discoloration, with no effective treatments currently available. This study aims to identify radiomic features from pre-treatment MRI scans associated with the development of RIM in breast cancer patients undergoing radiotherapy.

Material/Methods: This is a retrospective analysis of a single institutional registry of patients diagnosed with RIM following breast radiotherapy from 2008 to 2022. Clinical and histopathological data was reviewed. Pre-treatment MRI scans of these patients and matched controls were analyzed. Radiomic features were extracted from whole breast and fibroglandular tissue (FGT) regions of interest (ROIs). A total of 528 radiomic features were compared between patients who developed RIM and those who did not, using the Wilcoxon rank-sum test to identify statistically significant differences. Results: We evaluated ten patients with clinically diagnosed radiation-induced morphea (RIM), with a mean age of 63 years (range: 44-75 years). Among these, seven patients had biopsy-proven RIM. Both clinical and histological findings were correlated with radiomic analyses. 40% of the patients had a history of autoimmune disorders, including hypothyroidism, Graves’ disease, systemic sclerosis, and systemic lupus erythematosus. Radiomic analysis identified nine significant features, primarily related to tissue structure and texture. Eight of these features were from the contralateral breast, and one was from the ipsilateral breast. Conclusion: This study demonstrates that radiomic features extracted from pre-treatment MRI scans can serve as potential predictors for the development of RIM in breast cancer patients. The integration of clinical and histopathological data with radiomic analysis highlights the distinct changes in breast tissue architecture that precede RIM onset. These findings pave the way for the early identification of patients at risk, allowing for more personalized surveillance and management strategies. References: 1. Spalek, M., J. Jonska-Gmyrek, and J. Galecki, Radiation-induced morphea - a literature review. J Eur Acad Dermatol Venereol, 2015. 29 (2): p. 197-202. 2. Friedman, O., Y. Barnea, and A. Hafner, Underdiagnosed and disfiguring - Radiation-induced morphea following breast cancer treatment. Breast, 2018. 39 : p. 97-100. 3. Prasanna, P., P. Tiwari, and A. Madabhushi, Co-occurrence of Local Anisotropic Gradient Orientations (CoLlAGe): A new radiomics descriptor. Scientific Reports, 2016. 6 (1): p. 37241. 4. Conti, A., et al., Radiomics in breast cancer classification and prediction. Seminars in Cancer Biology, 2021. 72 : p. 238-250. Keywords: breast, radiomics, morphea

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Digital Poster Socioeconomic Disparities and Osteoarthritis Affect Hormone Therapy Adherence and Survival in Breast Cancer Patients Bum-Sup Jang, Ji Hyun Chang, Shin Kyung Hwan Radiation Oncology, Seoul National University Hospital, Seoul, Korea, Republic of Purpose/Objective: Adherence to adjuvant hormone therapy (AHT) is essential for maximizing survival benefits in breast cancer patients. This study aims to explore the complex interplay between socioeconomic disparities, pre-existing