Ultra-hypofractioNated Adjuvant Radiotherapy ± sImultaneous Integrated Boost for Low-risk Breast Cancer Patients

This trial is studying whether an ultra-short (ultra-hypofractionated) course of radiation therapy — delivering the full treatment in fewer, larger doses — is effective and safe for people with low-risk or early-stage breast cancer after surgery. Some patients may also receive a simultaneous boost to the area with the highest risk of recurrence. **You may be eligible if...** - You have been diagnosed with invasive or non-invasive (in situ) breast cancer - You have had breast-conserving surgery (lumpectomy) or mastectomy - Your cancer is at an early stage (no more than T2 and no more than 1 lymph node involved) - Your cancer has not spread to distant parts of the body **You may NOT be eligible if...** - Your cancer has spread to lymph nodes near the collarbone or chest wall - You have had prior chest radiation - You are pregnant - You have serious connective tissue diseases like active scleroderma or lupus Talk to your doctor to see if this trial is right for you.