In this study, data from 50 postmenopausal women with unilateral cT1N0 breast cancer, who underwent MRI as part of the THERMAC trial for a thermal ablation protocol, were analyzed. Additional MRI findings were classified as benign or malignant based on histopathology. Results showed that 30 % of patients had additional MRI findings, with 40 % of those being malignant, which led to exclusion from the trial and altered surgical management. Malignant lesions included lobular carcinoma, NST tumors, and multifocal/multicentric disease, while benign findings were predominantly fibroadenomas, cysts, and mastopathy. Malignant lesions required changes in the treatment approach, including exclusion from the ablation protocol, wider excisions, and in some cases, mastectomy. The study highlights the significant role of MRI in patient selection and treatment planning, emphasizing the need for further investigation into the long-term oncological outcomes in early-stage breast cancer patients.