It may be appropriate for women who have had lumpectomy or mastectomy. Women who receive radiation after mastectomy are typically those who have a greater chance of the cancer recurring.
More studies are under way to refine the treatment recommendations further.
The removed tissue has a positive margin of resection. Four or more lymph nodes were involved. You have a connective tissue disease, such as lupus or vasculitis, that makes you sensitive to the side effects of radiation. You are pregnant and so should not have radiation therapy. You are not willing to commit to the daily schedule of radiation therapy, or distance makes it impossible.