Inclusion Criteria:

1. Histological diagnosis of breast cancer
2. Patients younger than 40 years regardless of histological subtype, or patients between 40 and 70 years with lobular carcinoma, histological subtypes Luminal B Her2 positive, or with hormone receptors negative and Her2 positive (ErbB2), or triple negative (TNBC)
3. Signed informed consent
4. Clinical stage T1-T3, Nx-N3
5. Negative surgical margins (≥ 0.2 cm)
6. Clinical M0 in the previous 3 months
7. PS (ECOG) ≤2
8. No previous thoracic radiotherapy
9. Fertile women using contraceptive methods started during oncological treatment

Exclusion Criteria:

1. Patients with favorable characteristics (Luminal A, Luminal B Her2 negative, ≥ 40 years) undergoing partial irradiation
2. Patients who have undergone mastectomy
3. Multicentric tumors
4. Positive or close surgical margins (<0.2 cm)
5. BRCA1/2 positive (only if known)
6. Serious systemic diseases
7. Mental or other disorders that may prevent the patient from signing the informed consent
8. Previous invasive tumor, except skin cancer (excluding melanoma) unless the patient has been disease-free for at least 3 years (for example carcinoma in situ of the oral cavity or bladder)
9. Collagen or autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis, scleroderma, Sjogren's syndrome)
10. Evidence of distant metastases (M1)
11. Contraindication to treatment systemic
12. Pregnant women
13. Non-compliance with the dose limits established in the treatment plan