Purpose: To determine the technical success rate of sentinel lymph node biopsy in women with nonpalpable infiltrating breast cancer diagnosed by using percutaneous core biopsy and to determine the frequency with which sentinel lymph node biopsy obviated axillary dissection.
Materials and methods: Retrospective review revealed 33 women who underwent sentinel node biopsy after percutaneous core biopsy diagnosis of nonpalpable infiltrating breast cancer. Sentinel nodes were identified with radioisotope and blue dye; the procedure was technically successful if sentinel nodes were found at surgery. All sentinel nodes were excised. Axillary dissection was performed if tumor was present in sentinel nodes.
Results: Sentinel nodes were found at surgery in 30 women (91%). Sentinel nodes were identified with both radioisotope and blue dye in 22 (73%) of these women, with only radioisotope in six (20%), and with only blue dye in two (7%). Sentinel nodes were found in 12 (80%) of 15 women in the first half of the study versus all 18 (100%) women in the second half (P = .08). Sentinel nodes were free of tumor in 23 (77%) of 30 women. In six (86%) of seven women with tumor in sentinel nodes, the sentinel nodes were the only nodes with tumor.
Conclusion: Sentinel node biopsy was successful in 30 women (91%) with nonpalpable infiltrating carcinoma diagnosed with percutaneous core biopsy and obviated axillary dissection in 23 women (70%). Using both radioisotope and blue dye may increase the success rate. A learning curve exists, and success improves with experience.