Ultra Hypo-fractionated Adjuvant Whole Breast Radiation Therapy With Simultaneous Integrated Boost for Early-Stage Breast Cancer (H-ASSIST)

This study is testing an accelerated, shorter radiation schedule (ultra hypofractionation) with a simultaneous radiation boost to the tumor site for women with early-stage breast cancer who have had breast-conserving surgery. The goal is to deliver effective radiation in fewer treatment sessions. **You may be eligible if...** - You are a woman aged 50 or older - You have been diagnosed with early-stage invasive breast cancer or ductal carcinoma in situ (DCIS) - You have completed breast-conserving surgery (lumpectomy) with or without lymph node surgery - You are planned for whole breast radiation therapy (3D or IMRT) with a tumor bed boost **You may NOT be eligible if...** - You have had a previous breast reconstruction or implant - You have previously received radiation to the chest area - You have two or more separate breast cancers in the same breast - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.