One-Week radiation shows promise for breast cancer treatment

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Aged \>18 years old * Pathologically invasive breast cancer * Undergoing BCS or mastectomy with reconstruction allowed, along with axillary lymph node dissection or sentinel lymph node biopsy. * Axillary lymph node metastasis confirmed histologically (involving one or more nodes), or node-negative axilla with an indication for RNI as determined by the radiation oncologist. * Karnofsky Performance Status scoring ≥80, and anticipative overall survival \>5 years * Surgery wound healed without infection * Negative pathologically surgical margin * Estrogen-receptor, Progesterone-receptor, HER-2, and Ki67 index assessment on the primary breast tumor or axillary nodes is feasible. * Women of child-bearing potential must agree to use adequate contraception for up to 1 month before study treatment and the duration of study participation * Ability to understand and willingness to participate the research and sign the consent forms Exclusion Criteria: * Pathologically positive ipsilateral supraclavicular lymph node * Pathologically or radiologically confirmed involvement of ipsilateral internal mammary lymph nodes * Pregnant or lactating women * Severe non-neoplastic medical comorbidities that preclude radiation treatment (e.g., severe ischemic heart disease, arrhythmia, chronic obstructive pulmonary disease). * History of non-breast malignancy within 5 years with the exception of lobular carcinoma in situ, basal cell carcinoma of the skin, carcinoma in situ of skin, Adenocarcinoma in situ of the lung and carcinoma in situ of the cervix * simultaneous contralateral breast cancer or a prior history of ipsilateral breast cancer (including DCIS). * Previous radiotherapy to the neck, chest and/or ipsilateral axillary region * Active collagen vascular disease * Definitive pathological or radiologic evidence of distant metastatic disease * Primary T4 tumor