Radionuclide Sentinel Lymph Node Scan and Biopsy in Breast Cancer: The Experience in a Cancer Center

Abstract

Backgrounds: In the past, axillary lymph node dissection (ALND) was a routine procedure used in the surgery of invasive breast cancer. But procedure related morbidity was not uncommon. Sentinel lymph node (SLN) biopsy is a newly developed method to avoid unnecessary ALND. The purpose of this study was to evaluate the detection rate of radionuclide SLN scan and the negative predictive value of SLN biopsy in early stage breast cancer. Methods: This study included 49 patients of early stage breast cancer. All patients underwent radionuclide SLN scan on the day or the day before surgery. The radionuclide SLN scan was performed with subdermal injection of 0.3.-1.0 mCi of filtered (superscript 99m)Tc-sulfur colloid in the pen-tumor area or area around the scar of excision biopsy. Gamma camera mapping and intraoperative gamma probe were used for SLN biopsy. All SLNs were dissected followed by ALND. All lymph nodes were examined with hematoxylin and eosin (H&E) stain. Immunohistochemistry staining of cytokeratin were done in the SLNs negative on H&E examination to exclude micrometastasis. Results: SLNs were successfully detected by SLN scan in all of patients with detection rate of 100%. Positive SLN metastasis was found in 15 of 49 patients (30.6%), and thirty four patients were negative for SLN metastasis. There was one false negative SLN biopsy and the negative predictive value was 97.1%. Conclusion: Radionuclide SLN scan can provide information about the location and number of SLN(s) before SLN biopsy with high successful rate. The SLN biopsy was predictive for axillary lymph node status and should be used to avoid unnecessary ALND in early stage breast cancer.