Super-Hypofractionated Partial Breast Irradiation

Inclusion Criteria

• •1. ≥45 years old, \<75 years old women
• •2. Life expectancy \>5 years
• •3. Start radiotherapy within 12 weeks after breast-conserving surgery (or within 8 weeks from the end of chemotherapy)
• •4. Invasive ductal carcinoma grade 1-2, or mucinous carcinoma, papillary carcinoma, canalicular carcinoma, medullary carcinoma; primary tumor
• •≤3.0cm; both pN0 (axillary dissection or sentinel lymph node biopsy)
• •5. Low-risk DCIS: tumor ≤2.5cm, low to medium grade; axillary surgery is not required or pN0
• •6. Single focus (with MRI diagnosis)
• •7. Vascular tumor thrombus negative
• •8. ER and/or PR positivity (defined as strong positivity in \>1% of tumor cell nuclei)
• •9. Negative pathological margin≥2mm
• •10. Place metal markers on the tumor bed
• •11. Sign the informed consent form