Is blue dye indicated for sentinel lymph node biopsy in breast cancer patients with a positive lymphoscintigram?

Background: The use of isosulfan blue dye in sentinel node biopsy for breast cancer has been questioned because of its risk of allergic reaction. We hypothesized that blue dye could be safely omitted in the subgroup of patients who have evidence of successful sentinel node localization by lymphoscintigraphy. Methods: A retrospective review of patients with breast cancer and sentinel node biopsy was conducted. Information was collected on lymphoscintigraphy results, use of blue dye, and intraoperative and pathologic findings of sentinel nodes. Results: We identified 475 patients with breast cancer who underwent 478 sentinel node biopsies. Both dye and isotope were given in 418 cases, of which 380 had a positive lymphoscintigram. In 5 of the 380 cases with a positive lymphoscintigram, the sentinel nodes obtained were blue but not hot, for a 1.3% marginal benefit of dye in the technical success of the procedure. Sentinel nodes positive for metastasis were found in 102 of 380 cases; in 3 cases, the only positive sentinel node was blue but not hot. Omission of the blue dye tracer would have increased the false-negative rate of the sentinel node procedure by approximately 2.5%. Conclusions: Even in sentinel node biopsy cases with a positive lymphoscintigram, the use of blue dye is beneficial for both improving the technical success of the procedure and reducing the false-negative rate of the procedure. Because the marginal benefits of dye justify its routine use, strategies to minimize the toxicity of blue dye are warranted.