Localization of impalpable breast lesions and detection of sentinel lymph nodes through magnetic methods.

PURPOSE: The most commonly used technique for guiding the surgical removal of impalpable breast lesions is wire-guided localization (WGL). Potential complications of WGL include wire migration, wire transection, patient discomfort, and pneumothorax. Recently, another possibility for preoperative localization of breast lesions trough small steel seeds was developed. A magnetic handheld probe can be used both for localization of breast lesions and sentinel lymph nodes (SLNs) detection.

METHODS

In this study, we used a new technology for localizing breast lesions in conjunction with sentinel nodes (SLNs) detection through SPIO nanoparticles; both detected using a magnetic probe. The technique uses small steel markers (Magseed®) with magnetic properties, which are placed in breasts under ultrasonographic or mammographic guidance. 41 localization seeds were placed in 38 patients. In 27 patients with malignant tumors, simultaneous use of magnetic method for SLNs detection was used.

RESULTS

In all 38 patients, breast lesions were accurately localized using this method. No interference between Magseed signals and SPIO tracer signals were observed during magnetic probe measurements. All tumors were exscised with tumor-free surgical margins. The SLN biopsy was successful in all patients undergoing this procedure. The SLN median detection rate was 3 nodes.

CONCLUSIONS

The new magnetic methods are reliable alternatives for localizing breast lesions and SLN detection. They are well tolerated by patients and they can avoid the disadvantages of WGL. They have the potential to make tumor localization and SLN biopsy procedures possible in facilities without a nuclear medicine department or where radioisotope availability is limited.