The role of intraoperative lymphatic mapping and sentinel lymphadenectomy in the management of patients with breast cancer.

Sentinel lymph node dissection is a highly accurate method of axillary staging in patients with early breast cancer. Focused histopathologic evaluation of the SN improves axillary staging by increasing the detection of micrometastases, but the clinical significance of micrometastatic axillary involvement remains unclear. Sentinel lymph node dissection, which can be performed on an outpatient basis with local anesthesia, appears to have less morbidity and fewer complications and be more cost effective than routine ALND. Refinement of the technical aspects of the procedure has allowed identification of the SN in over 90% of patients, with 100% diagnostic accuracy in our most recent series. We have therefore abandoned routine ALND in selected patients with invasive breast cancer and reserve this procedure only for those with tumor-involved SNs or those in whom the SN cannot be identified. Several issues such as the definition of a hot SN, the kinetics of various radioisotopes used for breast lymphoscintigraphy, and the problem of radioactive scatter must be resolved. Because no other method accurately predicts axillary node status without complete ALND, SLND merits evaluation in a prospective, randomized multicenter trial to determine whether it may become the standard method of axillary staging.