The Clinical Utility of Indigo Carmine in Sentinel Lymph Node Biopsy of the Breast Cancer

Lee, Jae Bok; Bae, Jeoung Won; Son, Gil Soo; Koo, Bum Hwan

Abstract

BACKGROUND
The selection of blue dye or technetium radioisotope depends on the surgeon? experience or the availability of the center in sentinel lymph node biopsy (SLNB). The purpose of this study is to evaluate the possibility of clinical usage of indigo carmine in SLNB in breast cancer.
METHODS
From the July 2001 to the March 2004, 93 consecutive cases of Tis - T2 breast cancers without palpable axillary lymph nodes were enrolled to the SLNB. After usual preparation for the breast conserving surgery or mastectomy, the patients were intradermally injected with 5 ml of indigo carmine around the subareolar area. After 4 minutes has passed, usual axillary incision of breast conserving surgery was made, and the stained lymphatics were followed to the firstly encountered lymph nodes. The dissected nodes were sent to the department of pathology for frozen and permanent sections. After SLNB, axillary lymph node dissections (ALND) were completed regardless of the result of the frozen section.
RESULTS
The identification rate of SLNB using Indigo carmine was 97.8% (91/93). The axillary node metastases on complete ALND were 21 cases. 18 cases were detected with SLNB, and 3 cases were falsely reported as negative on SLNB. 11 cases had metastases in the sentinel nodes only (52.4%). Among the 3 false negative cases, one case had axillary metastasis solely in a node in level III (infraclavicular node). The sensitivity of the test was 85.7% (18/21), and the specificity was 100% (70/70). False negative rate was 9.5% (2/21), and negative predictive value was 95.9% (70/73).
CONCLUSIONS
Sentinel node biopsy using indigo carmine showed similar identification rate and false negative rate with other blue dye only methods including isosulfan blue. Because indigo carmine is more available and safe than isosulfan blue, it could be an alternative to isosulfan blue.