Correlation Between Concordance of Tracers, Order of Harvest, and Presence of Metastases in Sentinel Lymph Nodes With Breast Cancer

Abstract

There are various methods for the detection of sentinel lymph nodes (SLNs) in breast cancer by using a combined method with blue dye and radioisotope (RI) tracers. The purpose of the study was to reveal any correlation between concordance of the tracers and the order of harvest with the presence of metastases in SLNs. The outcomes were reviewed in 408 cases with stage 0 to II breast cancer; the combined method was used in which blue dye and RI were injected subcutaneously around the tumor. The radioactivity and blue staining in each harvested SLN were checked. In 330 cases (81%), SLNs contained both blue dye and RI tracers (blue-hot cases), and in 42 (10%) and 31 (8%) cases, the SLNs contained only the blue stain (blue-only cases) and only RI (hot-only cases), respectively. The overall metastatic rate was 25% on a patient basis. Blue-only cases had a higher rate (42%) of metastasis than hot-only cases (14%). The rate of nodes containing both blue dye and RI gradually decreased from the first SLNs harvested to the third SLNs harvested. The rate of nodes containing RI only increased with the number harvested, and there was not so much change in the rate of nodes containing blue only. These data suggest that RI tracer could detect a wide range of SLNs and that the blue dye tracer could efficiently detect SLNs with metastasis. The combined methods compensates for the deficiencies of each method and thus will probably help to prevent missing SLNs.