Effectiveness and Safety of Magseed-localization for Excision of Breast Lesions: A Prospective, Phase IV Trial

Surgical marker navigation system in breast conserving surgery and excision of non-palpable lesions: first Spanish single-center experience

BACKGROUND

Due to the establishment of screening mammography for breast cancer detection, the number of non-palpable lesions has increased. Thus, an optimal localization system is mandatory for the excision of non-palpable breast tumors.

OBJECTIVE

The aim of the study is to report the feasibility Surgical Marker Navigation (SMN) system Sirius Pintuition® for the excision of non-palpable breast tumors and non-palpable axillary lymph nodes.

METHODS

A retrospective observational study of patients undergoing breast-conserving surgery and lymph node excision guided by SMN between December 2022 and May 2023 was performed.

RESULTS

A total of 84 patients underwent excision of non-palpable breast tumors (77; 91.7%) or non-palpable axillary lymph-nodes (7; 8.3%) using SMN. In total, 94 markers were placed, in 74 patients (88.1%) only one marker was placed, whereas in 10 patients (11.9%) two markers were placed to correctly localize the lesion in the operating room. Most markers were placed using ultrasonographic guidance (69; 82.1%). Seventy-seven patients underwent breast-conserving surgery (91.7%) and 7 (8.3%) lymph node excision. In 10 cases (11.9%), the marker was accidentally displaced during surgery due to the use of magnetized instruments, although the specimen could be removed. In sum, all the markers were removed from the patients, although the marker retrieval rate, as we defined it (percentage of patients in whom the initial excised specimen contained the marker divided by the total number of patients), was 88.1%.

CONCLUSION

The use of Sirius Pintuition® SMN for non-palpable breast tumors and non-palpable lymph nodes is feasible, with a retrieval rate of 88.1%.

SCOUT® Localization Using MRI Guidance: Initial Experience

OBJECTIVE

The Food and Drug Administration approved the MRI-compatible wireless SCOUT localization system in April 2022. The purpose of this study was to evaluate feasibility of SCOUT localization under MRI guidance. We present our initial experience adopting MRI-guided SCOUT localization and compare it to MRI-guided wire localization.

METHODS

Electronic medical records and imaging were retrospectively reviewed for all patients who underwent MRI-guided SCOUT or wire localization at our institution between October 2022 and July 2023. Statistical analysis was performed using 2-sample proportion and Wilcoxon rank-sum tests.

RESULTS

There were 14 MRI-guided SCOUT and 23 MRI-guided wire localization cases during the study period. All SCOUTs were placed without complication and were considered to be in adequate proximity to the target. There was no significant difference in complication rate (P = .25) or days lapsed from MRI-detected abnormality to surgery (P = .82) between SCOUT and wire cases. SCOUT was placed at time of biopsy for 71% (10/14) of cases. 57% (8/14) of SCOUT cases were used for breast conservation surgery (BCS) compared to 100% (23/23) of wire cases (P <.01), with all 6 SCOUTs not used for BCS placed at time of biopsy.

CONCLUSION

MRI-guided SCOUT localization is feasible and offers an alternative to MRI-guided wire localization, with no SCOUT complications reported. SCOUT placement at time of biopsy obviates the need for an additional procedure, but predicting appropriateness is challenging, with 60% (6/10) of SCOUTs placed at time of MRI-guided biopsy not used for subsequent localization surgery.

SCOUT® Radar Localization at Time of Breast Biopsy

OBJECTIVE

Evaluate surgical utilization of SCOUT reflectors placed at breast biopsy.

METHODS

Consent was waived for this retrospective IRB-approved, HIPAA-compliant study. Breast biopsy examinations that reported the term "SCOUT" between January 2021 and June 2022 were identified using an institutional search engine. Cases were included if a SCOUT reflector was placed at time of breast biopsy and excluded if lesion pathology was already known. Analysis was performed at the lesion level. A multivariate-regression analysis evaluated 6 variables with potential impact on SCOUT utilization.

RESULTS

One hundred twenty-one lesions in 112 patients met inclusion criteria. Biopsy yielded 93% (113/121) malignant, 3% (4/121) elevated risk, 2% (2/121) benign-discordant, and 2% (2/121) benign-concordant results. Two cases lost to follow-up were excluded. SCOUT reflectors were utilized for lumpectomy (58%, 69/119 lesions) and excisional biopsy (6%, 7/119 lesions). SCOUTs were not utilized due to mastectomy (23%, 27/119), subsequent wire localization (2%, 2/119), and nonsurgical cases (12%, 14/119). Reflector placement utilization was 52% higher for findings less than 3.5 cm in size (P <.001), 33% higher in patients without prior treated breast cancer (P = .012), and 19% higher in patients with no suspicious ipsilateral lymph node (P = .048).

CONCLUSION

SCOUT reflector placement at time of biopsy was utilized for surgery 64% (76/119) of the time, although most (98%, 119/121) biopsies were malignant, elevated risk, or benign-discordant. Factors increasing reflector utilization include smaller lesion size, no suspicious ipsilateral lymph node, and no prior treated breast cancer.

Evolution of localization methods for non-palpable breast lesions: a literature review from a translational medicine perspective

Background and Objective

With an increasing number of non-palpable breast lesions detected due to improved screening, accurate localization of these lesions for surgery is crucial. This literature review explores the evolution of localization methods for non-palpable breast lesions, highlighting the translational journey from concept to clinical practice.

Methods

A comprehensive search of PubMed, Embase, and Scopus databases until September 2023 was conducted.

Key Content and Findings

Multiple methods have been developed throughout the past few decades. (I) Wire-guided localization (WGL) introduced in 1966, has become a reliable method for localization. Its simplicity and cost-effectiveness are its key advantages, but challenges include logistical constraints, patient discomfort, and potential wire migration. (II) Intraoperative ultrasound localization (IOUS) has shown promise in ensuring complete lesion removal with higher negative margin rates. However, its utility is limited to lesions visible on ultrasound (US) imaging. (III) Breast biopsy marker localization: the use of markers has improved the precision of localization without the need for wire. However, marker visibility remains a challenge despite improvements in their design. (IV) Radioactive techniques: radio-guided occult lesion localization (ROLL) and radioactive seed localization (RSL) offer flexibility in scheduling and improved patient comfort. However, they require close multidisciplinary collaboration and specific equipment due to radioactive concerns. (V) Other wireless non-radioactive techniques: wireless non-radioactive techniques have been developed in recent three decades to provide flexible and patient-friendly alternatives. It includes magnetic seed localization, radar techniques, and radiofrequency techniques. Their usage has been gaining popularity due to their safety profile and allowance of more flexible scheduling. However, their high cost and need for additional training remain a barrier to a wider adoption.

Conclusions

The evolution of breast lesion localization methods has progressed to more patient-friendly techniques, each with its unique advantages and limitations. Future research on patient-reported outcomes, cosmetic outcomes, breast biopsy markers and integration of augmented reality with breast lesion localization are needed.

Contribution of preoperative ultrasound-guided implantation of a magnetic seed for optimal localization and resection of vulvar angiosarcoma: A case report

INTRODUCTION

Vulvar cancer is a rare cause of malignancy among women. It is key for surgeons to achieve negative resection margins, as it greatly impacts patient's prognosis. Unfortunately, additional surgical procedures are often performed due to the regional anatomical complexity. Based on non-palpable breast tumors, where image-guided preoperative localization tools have enhanced the complete resection rates, we aimed at evaluating the feasibility of magnetic seed technique for localizing perineal lesions.

PRESENTATION OF THE CASE

We present the case of a 40-year-old female patient, who underwent iterative resections for a recurrent epithelioid angiosarcoma of the left labia major. Imaging revealed a suspicious regional involvement at 3 months of follow-up, for which another surgery was planned. We decided to target this non-palpable lesion with the Magnetic Seed technique to guide the intervention. A seed was inserted into the nodule under ultrasound guidance. Resection was then performed, with negative margins and no recurrence on last follow-up.

DISCUSSION

Surgical procedures with minimal extension are recommended in vulvar cancer, to limit the aesthetic and functional complication. Unfortunately, recurrences and residual tumors remain frequent, even higher when surgical margin safety is not achieved. Many studies have suggested the benefit of image-guided localization tools in non-palpable breast tumors. By reducing the excising volume and focusing on the lesions, relapse and complications are rarer. We considered Magnetic Seed to be the most appropriated technique for perineal lesions.

CONCLUSION

As for breast cancer, Magnetic Seed technique could be appropriate for non-palpable perineal lesions, optimizing resection margins with minimal procedures.

Magnetic seed versus skin tattoo localization of non-palpable breast lesions: a single institution cohort study

OBJECTIVE

The objective of this retrospective study was to investigate the accuracy and feasibility of magnetic seed compared to skin tattoo in preoperative localization of impalpable breast lesions in terms of accuracy of placement, re-excision and positive margins rates, and breast/surgical specimen volume ratio.

METHODS

We retrospectively analyzed 77 patients who underwent breast conservative surgery in our center from November 2020 to November 2021, with previous localization with skin tattoo or magnetic seed.

RESULTS

Thirty-seven magnetic seeds were placed in 36 patients (48.6%) and 40 skin tattoos were performed in the remaining cases (51.4%). The seeds were placed correctly at the two-view mammogram acquired after the insertion in 97.6% (36/37) of cases. With both methods, 100% of the index lesions were completely removed and found in the surgical specimen. The reported re-excision rate was 0% for both groups. A significant difference was observed in the volume of breast parenchyma removed between the two groups, inferior in the seed group (p = 0.046), especially in case of voluminous breasts (p = 0.003) and small lesions (dimension < 8 mm, p = 0.019).

CONCLUSIONS

Magnetic seed is a non-radioactive localization technique, feasible to place, recommended in case of non-palpable breast lesions, saving the breast parenchyma removed compared with skin tattoo, without reducing the accuracy.

CLINICAL RELEVANCE STATEMENT

Our findings contribute to the current evidence on preoperative localization techniques for non-palpable breast lesions, highlighting the efficacy of magnetic seed localization for deep and small lesions.

KEY POINTS

• Magnetic seed is a non-radioactive technique for the preoperative localization of non-palpable breast lesions studied in comparison with skin tattoo. • Magnetic seed is feasible to place in terms of post-placement migration and distance from the target lesion. • Magnetic seed is recommended in case of non-palpable breast lesions, saving the breast parenchyma removed without reducing the accuracy.

Magnetic Localization of Breast Lesions: A Large-Scale European Evaluation in a National Cancer Institute

INTRODUCTION

For decades the standard for preoperative breast lesions' localization has been wire localization. In recent years the options for nonwired localization have significantly expanded and include radioactive seeds, radar reflectors, radiofrequency identification tags and magnetic seeds. The aim of our study is to evaluate on a large scale the performance of preoperative magnetic seed localization of nonpalpable breast lesions.

MATERIAL AND METHODS

We prospectively collected data on all patients undergoing image-guided magnetic seed localization from September 2019 to December 2022. We analyzed imaging findings, histological results, and type of surgery. The primary outcome was the successful localization rate. Secondary outcomes were the successful placement rate, the ease of percutaneous positioning, the procedural complications, and the reintervention rate.

RESULTS

A total of 1123 magnetic seeds were placed in 1084 patients by 4 radiologists under ultrasound (1053) or stereotactic (70) guidance. All seeds were detectable transcutaneously in all breasts sizes and at all depths by 7 surgeons with a success rate of 100%. A total of 97.5% seeds were correctly placed into the target lesions (only 2.5% were dislocated). All radiologists have shown good compliance during the procedure, and there were no complications or safety issues. The reoperation rate was 5.1%.

CONCLUSIONS

Image-guided localization with magnetic seeds is an easy, safe, reliable, and effective method for localizing nonpalpable breast lesions. Both radiologists and surgeons agreed that the technology was intuitive to use and that it can be widely applied in preoperative localization in breast units.

Fluoroscopic Intraoperative Breast Neoplasm and Node Detection

BACKGROUND

Preoperative localization is necessary for nonpalpable breast lesions. A novel procedure, fluoroscopic intraoperative neoplasm and node detection (FIND), obviates the preoperative painful and potentially expensive localization by using intraoperative visualization of the standard clip placed during diagnostic biopsy. We hypothesized FIND would improve negative margin rates.

STUDY DESIGN

This is an IRB-approved retrospective study (September 2016 to March 2021). Electronic chart review identified breast and axillary node procedures using wire localization (WL) or FIND. Primary outcome was margin status. Secondary outcomes included re-excision rate, specimen weight, surgery time, and axillary node localization rate.

RESULTS

We identified 459 patients, of whom 116 (25.3%) underwent FIND and 343 (74.7%) WL. Of these, 68.1% of FIND and 72.0% of WL procedures were for malignant lesions. Final margin positivity was 5.1% (4 of 79) for FIND and 16.6% (41 of 247) for WL (p = 0.008). This difference lost statistical significance on multivariable logistic regression (p = 0.652). Re-excision rates were 7.6% and 14.6% for FIND and WL (p = 0.125), with an equivalent mean specimen weight (p = 0.502), and mean surgery time of 177.5 ± 81.7 and 157.1 ± 66.8 minutes, respectively (mean ± SD; p = 0.022). FIND identified all (29 of 29) targeted axillary nodes, and WL identified only 80.1% (21 of 26) (p = 0.019).

CONCLUSIONS

FIND has lower positive margin rates and a trend towards lower re-excision rates compared with WL, proving its value in localizing nonpalpable breast lesions. It also offers accurate localization of axillary nodes, valuable in the era of targeted axillary dissection. It is a method of visual localization, using a skill and equipment surgeons already have, and saves patients and medical systems an additional schedule-disruptive, painful procedure, especially valuable when using novel localization devices is cost-prohibitive.

An adapted protocol for magnetic localisation of nonpalpable breast cancer lesions and sentinel lymph nodes using a magnetic seed and superparamagnetic iron oxide tracer

BACKGROUND

Localisation techniques for nonpalpable breast cancer lesions and sentinel lymph node biopsy (SLNB) are associated with several drawbacks. A complete magnetic technique using magnetic seeds and superparamagnetic iron oxide tracer could be an interesting alternative. This study describes a clear protocol and the results of a combined magnetic approach.

METHODS

From August 2021 to February 2022 40 patients undergoing breast conserving surgery with SLNB were eligible for inclusion. Localisation was performed under ultrasound or stereotactic guidance, 1 week before surgery. Subsequently, 1 ml of tracer was injected at least 4 cm away from the tumour. Technetium-99m (^99m Tc) was injected 1 day before surgery as control procedure. Outcomes were SLNB time, a number of nodes detected with magnetic tracer including comparison with ^99m Tc, a success rate of malignant lesion detection and pathological margin assessment.

RESULTS

In total, 40 procedures were performed on 39 patients. A median of one node was retrieved. Sentinel nodes were retrieved using MagTrace® with a 92.5% detection rate compared to ^99m Tc. Wide local excision under magnetic guidance was successful in 35 cases.

CONCLUSIONS

This paper describes a combined magnetic approach for breast-conserving surgery and SLNB. An adapted protocol is described and could be used for implementation.

Combined use of magnetic seed and tracer in breast conserving surgery with sentinel lymph node biopsy for non-palpable breast lesions: A pilot study describing pitfalls and solutions

BACKGROUNDS

Traditionally, breast conserving surgery for non-palpable breast cancer is guided by wire or radioactive seed and radioactive tracer for sentinel lymph node biopsy (SLNB). Alternatively, a stain-less magnetic seed and superparamagnetic iron oxide tracer (SPIO) can be combined as a radioactive-free technique. The aim of this study was to define the pitfalls we encountered during implementation of this combined technique and provide solutions resulting in an instruction manual for a radio-active free procedure.

METHODS

Between January and March 2021, seventeen consecutive patients with cN0 non-palpable breast cancer were included. The magnetic seed was placed to localize the lesion and SPIO was used to identify the sentinel lymph node (SLN). A lymphoscintigraphy with Technetium-99m nano colloid was performed concomitantly in all patients as a control procedure for SPIO. Surgical outcomes are reported, including problems with placing and retrieval of the seed and SPIO and corresponding solutions.

RESULTS

Surgical excision was successful with invasive tumor-free margins in all patients. SLN detection was successful in 82% patients when compared to Technetium-99m. The most challenging issue was an overlapping magnetic signal of the seed and SPIO. Solutions are provided in detail.

CONCLUSIONS

Combined use of magnetic seed and SPIO for wide local excision and SLNB patients with non-palpable breast lesions appeared challenging due to overlapping magnetic signals. After multiple adaptations, the protocol proved to be feasible with an added advantage of eliminating the use of radioisotopes. We described the pitfalls and solutions resulting in an instruction manual for a totally radioactive-free procedure.

New Technology for the Breast Surgeon

New innovations aid the breast surgeon with better ability to localize tumors using wireless techniques, reduce re-excision rates by intraoperative margin evaluation and perform aesthetically; pleasing, and safe surgeries. In addition to improving oncological outcomes, we can continue to improve the quality of life for our patients through evolving surgeries including nerve-sparing mastectomies, robotic mastectomies, and lymphovascular surgeries (LYMPHA). Our article reviews current and evolving techniques and technology that all breast surgeons should add to his or her armamentarium to provide optimal surgical care.

Clinical Outcomes Using Magnetic Seeds as a Non-wire, Non-radioactive Alternative for Localization of Non-palpable Breast Lesions

BACKGROUND

Nonpalpable breast lesions require precise preoperative localization to facilitate negative margins with breast-conserving therapy. The traditional use of wires has several challenges including patient discomfort, wire migration, and coordination of schedules between radiology and the operating room. Radioactive seed localization overcomes some of these challenges, but radiation safety requirements have limited adoption of this technology. The authors examined their institutional experience with Magseed as an alternative technology for localization and compared outcomes with those of wire and radioactive seed localization.

METHODS

An institutional review board (IRB)-approved retrospective study was performed to evaluate patients who underwent excisional biopsy or segmental mastectomy after wire-guided localization (WGL), radioactive seed localization (RSL), or Magseed localization (ML). The clinical and pathologic factors of the three groups were assessed with a negative margin rate as the primary outcome measure.

RESULTS

Of the 1835 patients in the study, 825 underwent WGL, 449 underwent RSL, and 561 underwent ML. For the patients with either multiple lesions or a large lesion that required bracketing, multiple localization devices were placed in 31% of the WGL patients, 28% of the RSL patients, and 23% of the ML patients (p = 0.006). Negative margins were achieved in 91% of the WGL patients, 89% of the RSL patients, and 89% of the ML patients (p = 0.4).

CONCLUSION

Localization of non-palpable breast lesions using Magseed is a safe and effective alternative to WGL and RSL that overcomes radiation safety limitations and increases radiology and surgery scheduling efficiency.

Intraoperative Margin Trials in Breast Cancer

Purpose of Review

Obtaining negative margins in breast conservation surgery continues to be a challenge. Re-excisions are difficult for patients and expensive for the health systems. This paper reviews the literature on current strategies and intraoperative clinical trials to reduce positive margin rates.

Recent Findings

The best available data demonstrate that intraoperative imaging with ultrasound, intraoperative pathologic assessment such as frozen section, and cavity margins have been the most successful intraoperative strategies to reduce positive margins. Emerging technologies such as optical coherence tomography and fluorescent imaging need further study but may be important adjuncts.

Summary

There are several proven strategies to reduce positive margin rates to < 10%. Surgeons should utilize best available resources within their institutions to produce the best outcomes for their patients.

The Evolving Role of Radiofrequency Guided Localisation in Breast Surgery: A Systematic Review

Wire-guided localisation (WGL) has been the gold-standard for localising non-palpable breast lesions before excision. Due to its drawbacks, various wireless alternatives have been developed, including LOCalizer™, which is based on radio-frequency identification (RFID) technology. In this systematic review, we consulted EMBASE, Medline and PubMed databases using appropriate search terms regarding the use of RFID technology in the localisation of occult breast lesions. Retrospective and prospective studies were included if they quoted the number of patients, rate of successful placement, retrieval rate, margin positivity rate and the re-excision rate. In addition, studies comparing RFID to WGL were also included and analysed separately. Seven studies were included in this systematic review spanning 1151 patients and 1344 tags. The pooled deployment rate was 99.1% and retrieval rate was 100%. Re-excision rate was 13.9%. One complication was identified. Two studies compared RFID with WGL (128 vs. 282 patients respectively). For both techniques the re-excision rate was 15.6% (20/128 vs. 44/282 respectively, p value is 0.995). Based on our review, LOCalizer™ is safe and non-inferior to WGL in terms of successful localisation and re-excision rates. However, further research is required to assess the cost effectiveness of this approach and its impact on the aesthetic outcome compared with WGL and other wire free technologies to better inform decision making in service planning and provision.

Image-guided Localization Techniques for Nonpalpable Breast Lesions: An Opportunity for Multidisciplinary Patient-centered Care

Selection of a localization method for nonpalpable breast lesions offers an opportunity for institutions to seek multidisciplinary input to promote value-based, patient-centered care. The diverse range of nonpalpable breast and axillary pathologies identified through increased utilization of screening mammography often necessitates image-guided preoperative localization for accurate lesion identification and excision. Preoperative localization techniques for breast and axillary lesions have evolved to include both wire and nonwire methods, the latter of which include radioactive seeds, radar reflectors, magnetic seeds, and radiofrequency identification tag localizers. There are no statistically significant differences in surgical outcomes when comparing wire and nonwire localization devices. Factors to consider during selection and adoption of image-guided localization systems include physician preference and ease of use, workflow efficiency, and patient satisfaction.

Introducing SentiMag in a rural setting: A 5-year experience

BACKGROUND

The Sentimag device is a probe that contains a sensitive magnetometer which detects either an implantable magnetic marker (MagSeed) or an infectable superparamagnetic ironoxide nanoparticle tracer (MagTrace). MagSeed is used to localise impalpable breast lesions; MagTrace is used to identify sentinel lymph nodes. In Australasia, Sentinel lymph node (SLN) biopsy, using radioactive colloid injection, is a mainstay of prognostication in breast surgery in patients with a clinically negative axilla. In addition, radioactive seeds or hookwires have been used to detect impalpable breast lesions. Gisborne Hospital has been using the SentiMag device since June 2016 to both identify sentinel lymph nodes (Magtrace) and impalpable tumours (Magseed). This study gives perspective over more than 5 years on how this new technology can benefit patients and clinicians in the rural setting.

METHODS

Patient data had been collected by the operative surgeon prospectively and corroborated with the coding department. Consecutive cases performed by a single surgeon were included in this study. Inclusion criteria were: (1) any patient who needed localisation of an impalpable breast lesion; (2) any patient who needed a sentinel lymph node biopsy; (3) cases were collected from January 2013 with the large majority of cases were collected between January 2015 and Jan 2020. Comparisons were made between patients with different localisation methods. Basic demographics were collected at the time of the surgery and outcomes then recorded. Staging, lymph node status, lymph node detection rates and complications were collected. Mode of tumour and sentinel node location was recorded. Financial data was collected from administrative staff via receipts and invoices of purchases to the hospital.

RESULTS

Of the 125 patients included in this study: 23 underwent magnetic seed insertion; 15 underwent a hookwire insertion; 45 cases used MagTrace injection; 71 cases used radioactive colloid injection. There was a significantly higher detection rate of two or more sentinel nodes in the SentiMag group. (91% vs. 71.8%, p = 0.01). Neither complication rates, nor cancer detection rates were significantly different. Eighty-four (67.2%) cases did not require tumour location.

CONCLUSION

SentiMag is safe to use in a rural setting. Using the SentiMag system can simplify care for patients and surgeons and was shown to be cost effective in our hospital.

Prospective Registry Trial Assessing the Use of Magnetic Seeds to Locate Clipped Nodes After Neoadjuvant Chemotherapy for Breast Cancer Patients

BACKGROUND

Targeted axillary dissection (TAD) involves locating and removing both clipped nodes and sentinel nodes for assessment of the axillary response to neoadjuvant chemotherapy (NAC) by clinically node-positive breast cancer patients. Initial reports described radioactive seeds used for localization, which makes the technique difficult to implement in some settings. This trial was performed to determine whether magnetic seeds can be used to locate clipped axillary lymph nodes for removal.

METHODS

This prospective registry trial enrolled patients who had biopsy-proven node-positive disease with a clip placed in the node and treatment with NAC. A magnetic seed was placed under ultrasound guidance in the clipped node after NAC. All the patients underwent TAD.

RESULTS

Magnetic seeds were placed in 50 patients by 17 breast radiologists. All the patients had successful seed placement at the first attempt (mean time for localization was 6.1 min; range 1-30 min). The final position of the magnetic seed was within the node (n = 44, 88%), in the cortex (n = 3, 6%), less than 3 mm from the node (n = 2, 4%), or by the clip when the node could not be adequately visualized (n = 1, 2%). The magnetic seed was retrieved at surgery from all the patients. In 49 (98%) of the 50 cases, the clip and magnetic seed were retrieved from the same node. Surgeons rated the transcutaneous and intraoperative localization as easy for 43 (86%) of the 50 cases. No device-related adverse events occurred.

CONCLUSIONS

Localization and selective removal of clipped nodes can be accomplished safely and effectively using magnetic seeds.