Randomized clinical trial comparing blue dye with combined dye and isotope for sentinel lymph node biopsy in breast cancer

Background: Use of blue dye alone as a marker for sentinel lymph node (SLN) biopsy is effective, but combining it with isotope marking can improve the success rate. Use of the isotope adds extra cost and there are potential radiation hazards. The two techniques were compared in a randomized trial. Methods: Women with early breast cancer (less than 3 cm) and no palpable axillary nodes were recruited. Women older than 70 years with multicentric cancers or previous surgery to the breast or axilla were excluded. Patients were randomized to either blue dye alone or combined mapping for SLN biopsy. All women had a level I and H axillary dissection after the SLN biopsy. Results: A total of 123 patients were recruited, of whom five were excluded from analysis. Blue dye alone was used in 57 women and 61 had combined mapping. Baseline demographic data were similar in the two cohorts. The success rate of SLN biopsy was higher with combined mapping than with blue dye alone (100 versus 86 per cent; P = 0.002). The accuracy and false-negative rate were similar (accuracy 100 per cent for combined mapping versus 98 per cent for blue dye; false-negative rate 0 versus 5 per cent). Conclusion: Combined mapping was superior to blue dye alone in identification of the SLN, but accuracy and false-negative rates were similar.