A Prospective Study of Preoperative Tumor-bed Boost Followed by Oncoplastic Surgery and Adjuvant Whole Breast Radiotherapy for Early Stage Breast Cancer (BIRKIN) (BIRKIN)

Inclusion Criteria: Patients diagnosed with invasive breast cancer; cN0 based on clinical physical examination combined with at least two imaging tests, or axillary fine-needle biopsy proved pN0; Patients who plan to receive breast-conserving surgery or breast-conserving oncoplastic surgery; No distant metastasis; The primary tumour> 5mm from the skin, without invasion of the ribs or intercostal muscles; No neoadjuvant systemic therapy; Patients who can tolerate MRI; Life expectancy ≥5 years; Organ function is fine (Hemoglobin ≥100g/L, leukocyte ≥2×109/L, neutrophil ≥1×109/L, platelet ≥80×109/L; Creatinine 1.5 mg/dl or less; Alanine aminotransferase/aspartate aminotransferase ≤2.5×UNL.); Patients are willing to cooperate to follow up; Patients should sign the informed consent; Women of childbearing age need effective contraception. Exclusion Criteria: Concurrent active connective tissue disease; Patients who had radiotherapy to the ipsilateral breast or adjacent areas before; Other malignancies, which affect pateint life expectancy (except adequately treated basal cell carcinoma of the skin, carcinoma in situ of the cervix, superficial bladder neoplasms (no more than T1)); Severe comorbidities or active disease (Poorly controlled heart disease: New York Classification of Cardiac Function ≥ Grade 2, active coronary heart disease, unstable angina pectoris, arrhythmia requiring medical treatment/persistent refractory hypertension; Myocardial infarction, stroke within six months; Poorly controlled diabetes persists. Fasting blood glucose ≥ 10mmol/L, 2 hours postprandial blood glucose ≥ 13 mmol/L. Poorly controlled psychosis develops or worsens within six months; Active infection; Positive for antibodies to HIV).