Ultrasonographically guided injection improves localization of the radiolabeled sentinel lymph node in breast cancer

Background: Several reports have demonstrated the accurate prediction of axillary nodal status (ANS) with radiolocalization and selective resection of sentinel lymph nodes (SLN) in breast cancer. To date, no technique has proven to be superior in localizing the SLN. Methods: 1.0 mCi of clear unfiltered (99m)technetium sulfur colloid was injected under ultrasonographic (US) guidance around the perimeter of the breast lesion (palpable and nonpalpable) or previous biopsy site. Resection of the radiolocalized nodes was performed, followed by complete axillary lymph node dissection (AXLND). Results: Forty-two breast cancer patients underwent SLN biopsy after US-guided radiopharmaceutical injection. The SLN was localized in 41 patients (98%). The type of previously performed diagnostic biopsy did not influence the ability to localize the sentinel lymph node. Pathology revealed nodal metastasis in 7 of the 41 evaluable patients (17%). ANS was accurately predicted in 40 of 41 patients (98%). Conclusions: Early experience with radiolocalization and selective resection of SLN in breast cancer remains promising. Use of US-guided injection facilitates localization of the SLN, perhaps as a result of more accurate placement of the radionuclide marker. Use of this technique allowed for effective management of patients regardless of tumor size or the extent of prior biopsy, thereby expanding the potential number of eligible patients for SLN biopsy.