A multicentre prospective feasibility study of carbon dye tattooing of biopsied axillary node and surgical localisation in breast cancer patients
Background: The primary aim of this prospective, multicentre feasibility study was to determine whether the biopsied axillary node can be marked using black carbon dye and successfully identified at the time of surgery. Methods: We included breast cancer patients undergoing needle biopsy of the axillary node. The biopsied node was tattooed at the time of needle biopsy (fine needle aspiration or core biopsy) or at a separate visit with black carbon dye (Spot® or Black Eye™). Participants underwent primary surgery or neoadjuvant chemotherapy (NACT) and axillary surgery (SNB or ALND) as per routine care. Results: 110 patients were included. Median age of the women was 59 (range 31-88) years. 48 (44%) underwent SNB and 62 (56%) ALND. Median volume of dye injected was 2.0 ml (range 0.2-4.2). Tattooed node was identified intra-operatively in 90 (82%) patients. The identification rate was higher (76 of 88, 86%) in the primary surgery group compared with NACT (14 of 22, 64%) (p = 0.03). Of those undergoing NACT, the identification rate was better in the patients undergoing SNB (3 of 4, 75%) compared with ALND (11 of 18, 61%) (p > 0.99). The tattooed node was the sentinel node in 78% (28 of 36) patients in the primary surgery group and 100% (3 of 3) in the NACT group. There was no learning curve for surgeons or radiologists. The identification rate did not vary with timing between dye injection and surgery (p = 0.56), body mass index (p = 0.62) or volume of dye injected (p = 0.25). Conclusion: It is feasible to mark the axillary node with carbon dye and identify it intra-operatively. ClinicalTrials.gov: NCT03640819.