Sentinel lymph node biopsy using indigo carmine blue dye and the validity of ‘10% rule’ and ‘4 nodes rule’

This is the study which assessed sentinel lymph node biopsy (SNB) using indigo carmine blue dye and the validity of the ‘10% rule’ and ‘4 nodes rule’. Patients (302) were performed SNB using the combined radioisotope (RI)/indigo carmine dye method. Excised SLNs were confirmed whether they were stained and numbered in order of RI count and the percentage of radioactivity as compared to the hottest node was calculated. The relationship between histological diagnosis, dyeing and RI count was assessed. All the patients were detected SLN. Positive nodes were identified in 84 (27.8%) patients and were identified up to the third degree of hottest. All the hottest positive nodes were stained by indigo carmine. From the results, removing the three most radioactive SLNs identified all cases of nodal metastasis without complications. These stopping rules were valid and useful under indigo carmine use too.