Critères d'inclusion : - Woman ≥ 18 years who had radical surgery for invasive breast cancer pT1-3, pN0-N3, M0 with either mastectomy or breast conservation. The patient can be included no matter the status of oestrogen receptor, progesterone receptor, malignancy grade, HER2 status.
- ECOG 0-2
- Axillary lymph node dissection of the axilla where the findings give indication for regional nodes radiotherapy to levels +/-I, +/- II, +/-III, +/-IV, +/-interpectoral nodes (Rötter) and +/-the IMN.
- Sentinel node biopsy documenting limited nodal disease without an indication for axillary lymph node dissection according to institutional, national or other trial guidelines are accepted.
- The patient may be a candidate for a boost to the tumour bed.
- Adjuvant systemic therapy with chemotherapy, endocrine therapy and anti-HER2 treatment is accepted.
- Neoadjuvant chemotherapy for downstaging according to institutional or national guidelines is accepted if there is not an indication for a boost in the area of regional nodes after surgery.
- Primary systemic therapy of an operable breast cancer is accepted.
- If the patient is not treated with chemotherapy, the patient must be randomized within 8 weeks from last surgery. If the patient has received adjuvant chemotherapy, the patient must be randomized within 4 weeks after the last series of adjuvant chemotherapy or within 42 days from last surgery in case of surgery after neoajduvant or adjuvant chemotherapy.Breast implants are accepted.
- Connective tissue disease is allowed if the treating radiation oncologist finds radiotherapy indicated
- Postoperative infection and/or seroma giving indication for drainage during RT is accepted
- Women of childbearing potential must agree to use adequate contraception for the duration of study participation and up to 3 months following completion of therapy
- Signed informed consent
- Affiliated to the Social Security system