Hi @MaryAnnie,
Despite a mastectomy there was no clear margin between my tumor and the chest wall (muscle). The surgeon did take a shaving of my muscle which was clear of cancer cells.
I then had radiation (after chemo) to the chest wall. This was what was recommended by my doctors.
I am now almost 5 years from surgery and have had no recurrence.
Ask lots of questions until you feel ok about your choices.
Deanne xxx