Technical advances in sentinel lymph node biopsy for breast cancer.

Technical advances in the past several years have simplified and improved sentinel lymph node (SLN) biopsy for breast cancer. The use of alternative injection sites (skin or subareolar) yields high SLN identification rates and may shorten the learning curve associated with standard peri-tumoral injection. The dual-agent (radiocolloid plus blue dye) technique is now recommended to decrease false-negative rates, especially when surgeons are just learning how to perform SLN biopsy. Methylene blue may be an acceptable substitute for isosulfan blue dye and is associated with fewer hypersensitivity reactions. Hand-held gamma probes are now smaller and more maneuverable, with better shielding for directional detection of gamma rays. Routine preoperative lymphoscintigraphy can be avoided, thus facilitating operating room scheduling. Surgeons can use minimally invasive techniques to identify and remove internal mammary SLNs.