radiation vs mastectomy and reconstruction

My mother had neoadjuvant chemotherapy and a lumpectomy with axillary node disection.  The margins were close within a millimeter with five nodes positive (plus sentinal node).  He also said she had some pre cancerous cells. The doctor suggested going back in and taking a little more tissue and then radiation.  After thinking about it she decided to have a mastectomy.  He agreed and suggested she have reconstruction surgery (TRAM flap)at the same time.  Does this mean she doesn't have to have radiation?  If yes, should radiation be done first?

[CCF-RN,MSN-JS]

Dear vicbates, There is evidence that women with a high risk of loco-regional tumor recurrence after mastectomy will benefit from postoperative radiation therapy.  This high-risk group includes women with four or more positive lymph nodes or an advanced primary tumor.  Post-mastectomy radiation therapy must be coordinated with chemotherapy (it is not given at the same time as adjuvant chemotherapy), and should be delivered within the first 6 months following mastectomy.