Contraindications to breast-conserving therapy requiring radiotherapy include: Absolute: 1. radiotherapy during pregnancy; 2. diffuse suspicious or malignant-like manifestations of microcalcifications; 3. extensive lesions that cannot be resected locally through a single incision together to achieve negative margins with satisfactory cosmetic results; 4. diffuse positive marginal pathology. Relatively: 1. previous chest wall or breast radiotherapy; knowing the prescribed dose and target area is necessary; 2. active connective tissue disease involving the skin (especially scleroderma and lupus); 3. tumor >5 cm (grade 2B); 4. positive marginal pathology; 5. women with a known or suspected genetic predisposition to breast cancer: (1) breast-conserving therapy may have ipsilateral breast recurrence or contralateral (2) Prophylactic bilateral mastectomy may be considered to reduce the risk.