Optimized Criteria for Sentinel Lymph Node Biopsy in Patients with Clinically Node Negative Breast Cancer

Abstract

Purpose: Sentinel lymph node biopsy (SLNB) is a well-established staging procedure for patients with early breast cancer who have clinically negative axillary lymph node. However, no consensus exists about the number of sentinel lymph nodes (SLN) that should be removed based on radioactivity counts in breast cancer. We reviewed and analyzed cases in which more than one SLN was detected and there was at least one pathologically positive node.

Methods: We retrospectively studied breast cancer patients who underwent lymphoscintigraphy with injection of a radioactive colloid and SLNB along with intraoperative determination of radioactive counts of lymph nodes using a gamma probe between 2006 and 2018. In total 326 patients with more than one radioactive SLN were enrolled in this study.

Results: Fifty-four patients had nodal metastases, of whom 46 (85.2%) had metastases in the hottest lymph node. All metastatic SLNs were identified as one of the first three lymph nodes dissected. The lowest radioactive count of a positive SLN corresponded to 10% of that of the hottest node.

Conclusion: We suggest that removal of the first three lymph nodes or nodes covered by the "10% rule" is sufficient in SLNB for patients with breast cancer.