Background: Combined use of blue dye and radiocolloid is considered to be useful for sentinel lymph node (SLN) biopsy of breast cancer. Whether both techniques together is superior to either alone was analyzed.
Patients and methods: A consecutive series of 308 cases of breast cancer who underwent SLN biopsy using the combination technique was used. The frequency of a blue node or hot node was analyzed in all cases and only node-positive cases. Furthermore, the frequency of a blue node and hot node together, or either alone, and the highest radiocount of the SLNs in each case were examined for correlation with 8 clinicopathologic features. Three types of SLN containing both blue dye and radioactivity (blue-hot node), blue dye alone (blue-only node) and radioactivity alone (hot-only node), and the SLN radiocounts were analyzed for correlation with metastatic tumor.
Results: Of 308 cases, a blue node was present in 298 (97%), a hot node in 295 (96%), and either a blue or hot node in 306 (99%). The presence of a blue node or hot node was similarly affected by previous surgical biopsy and body mass index (BMI), and the presence of a hot node was also affected by age and tumor location. However, the presence of either a blue node or hot node was not affected by any of these characteristics. Of 77 node-positive cases, 8 (10%), 15 (19%) and 6 (8%) were considered to be node-negative based on blue node, hot node and either blue node or hot node positivity, respectively. The frequency of positivity for SLN metastasis decreased in order from blue-hot, blue-only to hot-only nodes. Of 62 cases with metastatic hot nodes, six (10%) were negative when the hottest node was examined, but the second-hottest node was positive.
Conclusions: The added value of the presence of blue node or hot node was confirmed in the SLN biopsy using the combination technique, which suggests that all blue nodes and hot nodes need to be harvested.