Percutaneous Sentinel Node Biopsy in Breast Cancer: Results of a Phase 1 Study.

BACKGROUND: While sentinel lymph node dissection (SLND) provides axillary staging, recent trials question the necessity of removing positive nonsentinel axillary lymph nodes (LN) in breast cancer. We sought to determine the technical feasibility of percutaneous core needle biopsy (PNB) of axillary sentinel lymph nodes (SLNs). METHODS: After dual tracer injection, 25 patients underwent intraoperative axillary ultrasound and ultrasound guided per PNB of the axillary LN at the site of radiotracer uptake, followed by standard SLND. The primary outcome measure was successful correlation of PNB with SLN, defined as: (1) similar final pathology in core and SLN and (2) presence of blue staining and/or radiotracer in the core or gross evidence of PNB at the SLN (e.g., transected SLN). RESULTS: Preincision axillary ultrasound identified a LN (mean size 1.15 ± 0.67 cm) at the site of radioactive tracer in 92 % (23 of 25) of cases. Gross evidence of PNB at the SLN was found in 76 % (19 of 25) of cases. Blue staining, radioisotope, and pathology matched in core and SLN specimens in 36 % (9 of 25), 64 % (16 of 25), and 72 % (18 of 25) of cases, respectively. Overall, successful correlation of core biopsy with SLN occurred in 72 % (18 of 25) of cases. CONCLUSIONS: Results of this phase I study demonstrate that PNB of the SLN is technically feasible, but further refinement of technique is warranted to improve correlation of core biopsy to SLND.