This study is being done to see if comprehensive regional nodal radiation therapy to the breast or chest wall and regional lymph node area using proton therapy delivered with a hypofractionated approach (less treatment days) will result in rates of treatment related skin and soft tissue side effects that are non-inferior compared to conventionally fractionated proton radiotherapy regimens.
The purpose of this research study is to learn more about the effects of using proton radiation therapy delivered over a shorter course of treatment (3 weeks) compared with a longer, standard course of treatment (5 weeks) for women with breast cancer who require radiotherapy to the breast/chest wall and regional lymph nodes.