Invasive chest wall recurrences (CWR) following mastectomy are typically treated with surgical excision, radiation therapy (RT) to the chest wall and supraclavicular (SCV) region, and appropriate systemic therapy. Repeat axillary surgery is not routinely performed if the axilla is clinically negative. We evaluated sentinel node biopsy (SNB) in patients with an isolated invasive CWR, for identification and biopsy rates, non-axillary drainage, and clinical implications for radiation fields and outcome.