Contemporary issues in the use of radiation therapy for early invasive breast cancer.

Breast conservation therapy consisting of tumor excision followed by whole breast irradiation is an accepted alternative to mastectomy for many women with early invasive breast cancer. Ongoing research questions include defining the role of the tumor bed irradiation boost, the identification of patients who are at sufficiently low risk of breast cancer recurrence to be treated with excision only, exploring tumor bed brachytherapy as an alternative to whole breast irradiation, and biologic considerations in the future local management of breast cancer.