The role of radiation therapy for primary breast cancer

The last 2 decades have seen the role of radiation therapy defined clearly. It is now realized that radiation therapy not only improves local control of breast cancer but also works with surgery and chemotherapy to improve th e probability of survival. The major lines of evidence supporting the use o f radiation therapy in DCIS, early-stage invasive disease, postmastectomy r adiation, and locally advanced breast cancer are outlined in this article, with an analysis of the remaining controversies concerning treatment and po tential complications of treatment.