Beyond Wires and Seeds: Reflector-guided Breast Lesion Localization and Excision

SAVI SCOUT® localization of breast lesions as a practical alternative to wires: Outcomes and suggestions for trouble-shooting

OBJECTIVE

The purpose of our study was to determine the frequency of successful SAVI SCOUT® localizations, to identify the factors contributing to unsuccessful procedures, and to provide a problem-solving algorithm to address those factors.

SUBJECTS AND METHODS

This retrospective study was performed following IRB approval. We included all consecutive patients with SCOUT® reflector placement performed at a single tertiary-care cancer center. Each case was reviewed and the following data were recorded: patient age, breast density, localization target, imaging modality used for guidance, post procedure mammogram reflector to skin and reflector to target distances, presence of the reflector in the specimen radiograph, excisional biopsy pathology and any procedure complications.

RESULTS

In 129 women, 152 SAVI SCOUT® reflectors were placed. Most patients had only 1 reflector placed, but 19 (15%) women had multiple reflectors placed for the purposes of bracketing, multiple excisions in 1 breast, bilateral excisions, or any combination thereof. The most common target was a mass (65%) and the most common modality for guidance was ultrasound (73%). SAVI SCOUT® localization was successful in 97%of reflectors, including 89% of reflectors targeting axillary lymph nodes. The most common failure encountered was the inability to obtain a signal in the radiology suite, due to (1) excessive target depth for the radiology suite handpiece and console, (2) obscuration by a hematoma, or (3) faulty reflector. No post-operative complications occurred.

CONCLUSION

The SAVI SCOUT® surgical guidance system is an accurate and reliable method for localization of non-palpable breast lesions, bracketing, and axillary lymph nodes.

Impact of Advancing Technology on Diagnosis and Treatment of Breast Cancer

New emerging breast imaging techniques have shown great promise in breast cancer screening, evaluation of extent of disease, and response to neoadjuvant therapy. Tomosynthesis, allows 3-dimensional imaging of the breast, and increases breast cancer detection. Fast abbreviated MRI has reduced time and costs associated with traditional breast MRI while maintaining cancer detection. Diffusion-weighted imaging is a functional MRI technique that does not require contrast and has shown potential in screening, lesion characterization and also evaluation of treatment response. New image-guided preoperative localizations are available that have increased patient satisfaction and decreased operating room delays.

Safety and feasibility of breast lesion localization using magnetic seeds (Magseed): a multi-centre, open-label cohort study

Purpose

Wire localization has several disadvantages, notably wire migration and difficulty scheduling the procedure close to surgery. Radioactive seed localization overcomes these disadvantages, but implementation is limited due to radiation safety requirements. Magnetic seeds potentially offer the logistical benefits and transcutaneous detection equivalence of a radioactive seed, with easier implementation. This study was designed to evaluate the feasibility and safety of using magnetic seeds for breast lesion localization.

Methods

A two-centre open-label cohort study to assess the feasibility and safety of magnetic seed (Magseed) localization of breast lesions. Magseeds were placed under radiological guidance into women having total mastectomy surgery. The primary outcome measure was seed migration distance. Secondary outcome measures included accuracy of placement, ease of transcutaneous detection, seed integrity and safety.

Results

Twenty-nine Magseeds were placed into the breasts of 28 patients under ultrasound guidance. There was no migration of the seeds between placement and surgery. Twenty-seven seeds were placed directly in the target lesion with the other seeds being 2 and 3 mm away. All seeds were detectable transcutaneously in all breast sizes and at all depths. There were no complications or safety issues.

Conclusions

Magnetic seeds are a feasible and safe method of breast lesion localization. They can be accurately placed, demonstrate no migration in this feasibility study and are detectable in all sizes and depths of breast tissue. Now that safety and feasibility have been demonstrated, further clinical studies are required to evaluate the seed’s effectiveness in wide local excision surgery.

Enhanced Axillary Evaluation Using Reflector-Guided Sentinel Lymph Node Biopsy: A Prospective Feasibility Study and Comparison With Conventional Lymphatic Mapping Techniques

BACKGROUND

Recently there are efforts to use sentinel lymph node biopsy (SLNB) techniques after neoadjuvant chemotherapy (NAC) to minimize axillary surgery. However, studies have shown higher false negative rates in this scenario, which might result in inaccurate assessment of treatment response and patient prognosis as well as leaving residual disease behind. In this study, we describe the use of reflector-guided excision of the percutaneously biopsied node (PBN) as an aid to conventional SLNB and its predictor of the axillary status after NAC.

PATIENTS AND METHODS

This was a single-institution analysis of patients who underwent axillary fiducial-reflector placement and subsequent SLNB compared with conventional SLNB.

RESULTS

Nineteen patients in the reflector group were matched with 19 patients who underwent conventional SLNB (conventional group). The PBN was identified in the SLNB in 19 patients (100%) in the reflector group and in 9 patients (47.3%) in the conventional group (P = .002). In the remaining 10 patients in the conventional group, the PBN was identified in the axillary lymph node dissection specimen in 4 patients (21%) and not identified in 6 patients (31.7%). Among the 38 patients, traditional mapping failed to identify the PBN in 13 patients (34.2%). The PBN was negative in 10 patients (36%) and positive in 18 patients (64%); no additional positive nodes were identified among patients with a negative PBN, correctly reflecting the status of the axilla in 100% of cases.

CONCLUSION

Mapping failure after NAC might compromise SLNB. Reflector-guided excision of the PBN is not only facile and feasible, but more accurately reflects the status of the axilla after NAC.

Innovations in image-guided preoperative breast lesion localization

Screening mammography increases detection of non-palpable breast lesions requiring image-guided localization prior to surgery. Accurate preoperative localization is crucial for successful surgical outcomes. Wire-guided localization is currently the most widely used localization method for non-palpable breast lesions; however, this technique has multiple disadvantages including patient discomfort, possible wire transection and migration, suboptimal surgical incision placement due to wire location and limited scheduling flexibility decreasing operating room efficiency. As a result, promising new techniques including radioactive seed localization, non-radioactive radar localization and magnetic seed localization have been developed as alternatives. In this article, we provide an overview of these techniques and discuss their advantages, drawbacks and currently available outcome data.