How would you manage the axilla of a patient with a recurrent ipsilateral breast cancer treated with lumpectomy, sentinel node biopsy, and IORT?  

The patient is a woman in her 60s with a history of a grade 1 ER-positive, HER2 negative pT1bN0 invasive ductal carcinoma treated with lumpectomy, whole-breast RT and tamoxifen >10 years ago.

The patient has a new grade 3 ER-positive, HER2 negative cT1cN0 invasive ductal carcinoma in the same breast (but different location within the breast) and refuses mastectomy, so is treated on a clinical trial of breast-conserving surgery and sentinel node biopsy, followed by 50 kV IORT.

Pathology reveals 9 mm grade 3 primary, with negative margins, 1/1 sentinel lymph node with a micrometastasis (1.2 mm, without ENE).  

Would you recommend axillary dissection for this patient? Axillary radiation?  Appropriate systemic treatment based on Oncotype, with no further surgery or radiation to the axilla? MD Anderson Nomogram risk of non-sentinel lymph nodes is 19%.