We summarise here the information to be provided to women and referring physicians about percutaneous breast biopsy and lesion localisation under imaging guidance. After explaining why a preoperative diagnosis with a percutaneous biopsy is preferred to surgical biopsy, we illustrate the criteria used by radiologists for choosing the most appropriate combination of device type for sampling and imaging technique for guidance. Then, we describe the commonly used devices, from fine-needle sampling to tissue biopsy with larger needles, namely core needle biopsy and vacuum-assisted biopsy, and how mammography, digital breast tomosynthesis, ultrasound, or magnetic resonance imaging work for targeting the lesion for sampling or localisation. The differences among the techniques available for localisation (carbon marking, metallic wire, radiotracer injection, radioactive seed, and magnetic seed localisation) are illustrated. Type and rate of possible complications are described and the issue of concomitant antiplatelet or anticoagulant therapy is also addressed. The importance of pathological-radiological correlation is highlighted: when evaluating the results of any needle sampling, the radiologist must check the concordance between the cytology/pathology report of the sample and the radiological appearance of the biopsied lesion. We recommend that special attention is paid to a proper and tactful approach when communicating to the woman the need for tissue sampling as well as the possibility of cancer diagnosis, repeat tissue sampling, and or even surgery when tissue sampling shows a lesion with uncertain malignant potential (also referred to as “high-risk” or B3 lesions). Finally, seven frequently asked questions are answered.

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Image-guided breast biopsy and localisation: recommendations for information to women and referring physicians by the European Society of Breast Imaging

Many patients with breast cancer are candidates for breast conservation therapy. This group includes individuals with small nonpalpable tumors detected at screening mammography and those with sufficient tumor shrinkage after neoadjuvant chemotherapy. Breast conservation surgery often requires the use of an imaging-guided preoperative localization procedure, during which a device is placed within or adjacent to the target lesion to guide the surgeon intraoperatively. For decades, wire localization has been the standard for preoperative localization in breast imaging. With this method, a wire is placed in the breast percutaneously, with the distal wire segment positioned adjacent to the abnormality and the proximal wire segment remaining outside the breast. Because of the external component of the wire, the patient must be compliant, and care must be taken to not disturb the wire's position before surgery. Scheduling flexibility is also limited because the wire localization must be performed on the same day as the subsequent surgery. More recently, the available options for performing preoperative localization have expanded greatly and now include the use of nonwire devices such as radioactive and magnetic seeds, radar reflectors, and radiofrequency identification tags. Nonwire localization devices can be placed days in advance of the surgery, at the patient's convenience, to avoid wire-related challenges and complications. They are placed percutaneously within or adjacent to the target breast lesion and detected intraoperatively by using a probe outside the breast.©RSNA, 2019.

https://pubs.rsna.org/doi/pdf/10.1148/rg.2019190041

The Wire and Beyond: Recent Advances in Breast Imaging Preoperative Needle Localization

Introduction Magseed is an alternative method of localising non-palpable breast lesions that has addressed many of the limitations of wire guided localisation (WGL). It consists of a paramagnetic seed that can be visualised on mammography and ultrasound. Intraoperative localisation of the seed is achieved with the use of the Sentimag probe. The aim of this study was to prospectively compare localisation in patients undergoing wide local excision (WLE) for non-palpable lesions between Magseed and WGL. Methods We prospectively collected data on all patients undergoing image-guided WLE between October 2017 and September 2018 in two academic breast units with a planned accrual of 100 consecutive patients undergoing Magseed localisation. Data was also collected on a cohort of 100 consecutive patients undergoing WGL in the same time period. Results Demographic and disease characteristics were well balanced between the two groups. 4/104 patients were converted preoperatively from Magseed to WGL (2 misplaced Magseeds; 2 undetected Magseeds). Intraoperative identification and excision of the localised lesion was successful in all patients as confirmed with specimen radiography. Overall no significant differences were observed in the proportion of patients requiring re-excision between the two groups (Magseed 16% vs. WGL 14% p = 0.692). Specimens size by weight and volume was similar for both groups (Magseed 39.6 g vs. WGL 44.5 g p = 0.206 and 90.1 cm3 for Magseed vs. 95.6 cm3 for WGL p = 0.579). Conclusions In our series Magseed localisation proved to be as reliable and effective as WGL in terms of lesion identification, excision with tumour free margins and specimen weight.

Is the future magnetic? Magseed localisation for non palpable breast cancer. A multi-centre non randomised control study.

Background/aim Wire-guided localisation (WGL) remains the most widely used technique for the localisation of non-palpable breast lesions; however, recent technological advances have resulted in non-wire, non-radioactive alternatives, such as magnetic seeds (Magseeds). The aim of this pooled analysis was to determine whether Magseeds are an effective tool for localising non-palpable breast lesions. Materials and methods Various databases were searched for publications which reported data on the localisation and placement rates of Magseed. Data on re-excision rates under use of Magseed and WGL were also collected. Results Sixteen studies, spanning the insertion of 1,559 Magseeds, were analysed. The pooled analysis showed a successful placement rate of 94.42% and a successful localisation rate of 99.86%. Four studies were analysed in a separate pooled analysis and showed no statistically significant difference between re-excision rates using Magseeds and WGL. Conclusion The use of Magseeds is an effective, non-inferior alternative to WGL that overcomes many of the limitations of the latter.

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Evolving Role of Magseed in Wireless Localization of Breast Lesions: Systematic Review and Pooled Analysis of 1,559 Procedures.

OBJECTIVE. The objective of this study was to evaluate the feasibility of using a magnetic seed system for preoperative localization of axillary lymph nodes in patients with breast cancer. MATERIALS AND METHODS. We performed a retrospective analysis that included patients with breast cancer who underwent preoperative magnetic seed localization of axillary lymph nodes at our institution between January 1, 2017, and January 1, 2019. Magseed (Endomag) is a nonradioactive inducible magnetic seed that is induced to become a magnet when under the influence of its detector in the operating room. Clinical history, prior axillary sampling and clip placement, and procedure details and surgical outcomes were determined from a search of our PACS and electronic medical records. RESULTS. Thirty-five patients (34 women and one man) composed our study cohort. The mean patient age was 56 years (range, 32-78 years). One patient underwent two separate consecutive localizations for two separate operations, and another patient had bilateral lesions, for a total of 37 axillary lymph node localizations. One case of seed misplacement occurred during the ultrasound-guided localization procedure, resulting in immediate placement of a second seed, for a total of 38 Magseeds placed. All seeds were placed under ultrasound guidance. The mean number of days from seed placement to surgery was 5 days (range, 0-31 days). Thirty-seven of 38 Magseeds (97%) were documented to be successfully retrieved in the operating room. CONCLUSION. Magseed localization appears to be a safe, nonradioactive way to accurately localize axillary lymph nodes preoperatively.

Feasibility of Magnetic Seeds for Preoperative Localization of Axillary Lymph Nodes in Breast Cancer Treatment.

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. 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. 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. 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.

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John Murphy

Papers

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

Deposition of (211~1.0nm/123~10nm)xN Multilayer Coated Conductors on Ni-Based Textured Substrates