Sentinel Lymph Node Mapping in Post-Mastectomy Chest Wall Recurrences: Influence on Radiation Treatment Fields and Outcome.

BACKGROUND AND OBJECTIVES: 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. METHODS: Between 2008 and 2013, 12/19 women with an isolated invasive CWR had sentinel node (SN) mapping with Tc99m. Median age was 53 years, and 92% (11/12) had initial path N0 disease. All had prior SNB, with axillary dissection in one patient. RESULTS: Overall, 83% (10/12) had successful mapping, with 70% (7/10) having an axillary SN. Ninety percent (9/10) had successful axillary node biopsy, with one patient having positive nodes. SCV RT was omitted in those with negative axillary nodes. With a median follow-up of 4.6 years from recurrence, there have been no SCV recurrences and no instances of lymphedema. CONCLUSIONS: SNB is possible in women with an isolated CWR with acceptable identification and biopsy rates. Omission of routine irradiation of the SCV region has not jeopardized regional control and results in decreased morbidity.