Preoperative needle biopsy of sentinel lymph nodes using intradermal microbubbles and contrast-enhanced ultrasound in patients with breast cancer.

OBJECTIVE

The purpose of this study was to assess whether sentinel lymph nodes (SLNs) that undergo targeted needle biopsy after identification by contrast-enhanced ultrasound (CEUS) using intradermally injected microbubbles results in more node-positive breast cancer patients being diagnosed preoperatively. Furthermore, we sought to determine whether the addition of CEUS to gray-scale sonography of the axilla reduces the number of patients having axillary lymph node (ALN) dissection as a second procedure.

SUBJECTS AND

METHODS

Intradermal microbubble injection was performed in 136 breast cancer patients who had no abnormal ALNs on routine gray-scale axillary sonography. When an enhancing ALN was visualized, percutaneous sonography-guided fine-needle aspiration cytology or core needle biopsy was performed. Depending on the biopsy results, patients underwent SLN biopsy or ALN dissection. If the putative SLN biopsy was positive or a biopsy tract was seen in the excised SLN, the procedure was defined as successful.

RESULTS

SLNs were identified and biopsied in 126 of the 136 cases (93%). Seventeen patients had positive sonography-guided biopsy results (13%) and were treated with immediate ALN dissection. In seven patients, the biopsied node was the only positive node. The remaining 109 patients underwent SLN biopsy. In nine cases (8%), a positive lymph node was identified. Four of these false-negative cases had only micrometastases.

CONCLUSION

SLNs can be identified and biopsied using CEUS to increase the accuracy of preoperative axillary staging. If the needle biopsy result is negative, conventional SLN biopsy is indicated.