Breast-Conserving Surgery Guided with Magnetic Seeds vs. Wires: A Single-Institution Experience

PURPOSE

The aim of this study is to describe our initial experience using magnetic seeds (Magseed®) to guide breast-conserving surgery in non-palpable breast lesions and compare the use of magnetic seed with wires to guide breast-conserving surgery in terms of clinical and pathological characteristics.

METHODS

We performed a retrospective study including all breast-conserving surgeries for non-palpable breast lesions under 16 mm from June 2018 to May 2021. We compared breast-conserving surgeries guided with magnetic seeds (Magseed®) to those guided with wires, analyzing tumor and patient characteristics, surgical time, and pathological results of the surgical specimens.

RESULTS

Data from 225 cases were collected, including 149 cases guided by magnetic seeds and 76 cases guided by wires. The breast lesion was localized in every case. Both cohorts were similar regarding clinical and pathological characteristics. We found significant statistical differences (p < 0.02) in terms of the median volume (cm3) of the excised specimen, which was lower (29.3%) in the magnetic seed group compared with the wire group (32.5 [20.5-60.0]/46.0 [20.3-118.7]). We did not find significant differences regarding surgical time (min) or the affected or close margins.

CONCLUSION

In our experience, the use of magnetic seed (Magseed®) is a feasible option to guide breast-conserving surgery of non-palpable lesions and enabled us to resect less breast tissue.

Miniature magneto-mechanical resonators for wireless tracking and sensing

Sensor miniaturization enables applications such as minimally invasive medical procedures or patient monitoring by providing process feedback in situ. Ideally, miniature sensors should be wireless, inexpensive, and allow for remote detection over sufficient distance by an affordable detection system. We analyze the signal strength of wireless sensors theoretically and derive a simple design of high-signal resonant magneto-mechanical sensors featuring volumes below 1 cubic millimeter. As examples, we demonstrate real-time tracking of position and attitude of a flying bee, navigation of a biopsy needle, tracking of a free-flowing marker, and sensing of pressure and temperature, all in unshielded environments. The achieved sensor size, measurement accuracy, and workspace of ~25 centimeters show the potential for a low-cost wireless tracking and sensing platform for medical and nonmedical applications.

An Audit on Oncological Safety with Magseed Localised Breast Conserving Surgery

Wire-localised wide local excision (W-WLE) has been standard of care for impalpable breast lesions. Logistics and risks of wire localisation can be challenging. Magseed-localised wide local excision (M-WLE) is an alternative to W-WLE. We compare safety parameters and length of hospital stay (LOS) in patients undergoing M-WLE to W-WLE. All M-WLEs performed at single institution over an 8-month period were included and compared to historic matched cohort of W-WLEs who would have been suitable for Magseed localisation. Data including patient demographics, successful placements, re-excision rates, tumour size, and length of stay (LOS) was analysed. Two hundred thirty-eight patients were included in the study. Cancers were safely excised in all cases. A significant difference in re-excisions rates favouring M-WLE group was seen (2.9% vs 10.4%). Median waiting time to surgery was significantly shorter in M-WLE group (4 h 15 min vs 7 h 3 min). No significant difference in median LOS between the two groups was seen. M-WLE has been shown to be oncologically safe and non-inferior to W-WLE with significantly lower re-excision rate. Reduced pre-operative waiting time in the M-WLE group will have a positive effect on patient journey. Further research should focus on potential impact on day-bed utilisation and theatre efficiency.

Preoperative localisation of nonpalpable breast lesions using magnetic markers in a tertiary cancer centre

Background

We retrospectively evaluated safety and performance of magnetic seed localisation of nonpalpable breast lesions.

Methods

We reviewed records of patients with nonpalpable breast lesions preoperative localised by placing magnetic Magseed® marker between February 2019 and December 2020. During surgery, Sentimag® magnetic probe was used to localise the marker and guide surgery. Safety, lesion identification and excision with tumour with free margins and re-excision rate were assessed.

Results

A total of 77 Magseed® devices were placed into the breasts of 73 patients, 44 under ultrasound and 33 under stereotactic guidance (4 bilateral). All devices were retrieved as were the target lesions. Magnetic marker placement was successful in all cases without any adverse event. Intraoperative identification and excision of the localised lesion were successful in 77 of 77 of cases (100%). In three cases (all of them calcifications with the seed placed under stereotactic guidance), the seed did not reach the exact target position of the biopsy clip; thus, larger excision was needed, with localisation failure attributed to incorrect clip insertion (n = 1) or to clip dislocation (n = 2). Migration of the marker was negligible in all patients. Complete excision after the initial procedure with at least 1-mm disease-free margins was obtained in 74 out of 77 (96.1%) lesions. The re-excision rate was 3 out of 77 (4%).

Conclusions

Magnetic marker localisation for nonpalpable breast lesions was safe, reliable, and effective in terms of lesion identification, excision with tumour-free margins and re-excision rate.

Comparison of Wireless Localization Alternatives with Wire Localization for Nonpalpable Breast Lesions

BACKGROUND

Radiofrequency identification tag localization (TL) and magnetic seed localization (MSL) are alternatives to wire localization (WL) for excision of nonpalpable breast lesions. We sought to compare localization methods with respect to operative time, specimen volume, and re-excision rate.

STUDY DESIGN

A retrospective cohort analysis was performed on TL, MSL, and WL lumpectomies and excisional biopsies at a single institution. Association between localization method and operative time, specimen volume, and re-excision rate was assessed by multiple logistic regression using odds ratios (ORs) and 95% CIs.

RESULTS

A total of 506 procedures were included: 147 TL (29.0%), 140 MSL (27.7%), and 219 WL (43.3%). On logistic regression analysis, MSL was associated with longer operative times than WL for excisional biopsies only (OR 4.24, 95% CI 1.92 to 9.34, p < 0.001). Mean excisional biopsy time was 39.1 minutes for MSL and 33.0 minutes for WL. Specimen volume did not vary significantly across surgery types between localization methods. In an analysis of all lumpectomies with an indication of carcinoma, marker choice was not associated with rate of re-excision (TL vs WL OR 0.64, 95% CI 0.26 to 1.60, p = 0.342; MSL vs WL OR 1.22, 95% CI 0.60 to 2.49, p = 0.587; TL vs MSL OR 0.65, 95% CI 0.26 to 1.64, p = 0.359).

CONCLUSION

TL, MSL, and WL are comparable in performance for excision of nonpalpable breast lesions. Although increased operative time associated with MSL vs WL excisional biopsies is statistically significant, clinical significance warrants additional study. With similar outcomes, physicians may choose the marker most appropriate for the patient and setting.

Wireless localisation of breast lesions with MagSeed. A radiological perspective of 300 cases

OBJECTIVES

The purpose of this article is to review the technical and radiological aspects of MagSeed® localisation, to assess its accuracy based on post-localisation mammograms and excision specimen X-rays and to discuss the radiological experience of our institutions.

METHODS

Two-year data were collected retrospectively from three NHS boards from the West of Scotland. A total of 309 MagSeeds® were inserted under mammographic or ultrasonographic guidance in 300 women with unifocal, multifocal and/or bilateral breast lesions at the day of surgery or up to 30 days prior to it. Radiological review of post-localisation mammograms and intraoperative specimen X-rays as well as a review of the surgical outcomes were performed to assess the accuracy and efficacy of the method. Our experience relating to the technique's strengths and downsides were also noted.

RESULTS

The MagSeeds® were inserted on average 7.2 days before surgery. The localisation technique was straight forward for the radiologists. In 99% of the cases, the MagSeed® was successfully deployed and 100% of the successfully localised lesions were excised at surgery. There was no difference in the accuracy of the localisation whether this was mammographically or ultrasonographically guided. On post-localisation mammograms, the MagSeed® was radiologically accurately positioned in 97.3% of the cases. No delayed MagSeed® migration was observed. On the specimen X-rays, the lesion was centrally positioned in 45.1%, eccentric within more than 1 mm from the margin in 35.7% and in 14.8% it was at the specimen's margin. The re-excision rate was 18.3%.

CONCLUSION

The MagSeed® is an accurate and reliable localisation method in breast conserving surgery with good surgical outcomes.

ADVANCES IN KNOWLEDGE

To our knowledge, the radiological aspects of MagSeed® localisation have not been widely described in peer-reviewed journals thus far.

Magseed localisation of non-palpable breast lesions: experience from a single centre

AIM

To prospectively analyse patients undergoing magnetic seed (Magseed) localisation (MSL) to evaluate the outcome, and to retrospectively compare re-excision rates for MSL with previous wire-guided localisation (WGL) to assess the hypothesis that the introduction of MSL may lead to a lower re-excision rate.

MATERIALS AND METHODS

MSL commenced at University Hospital Crosshouse in December 2017. No other changes were made to radiological or surgical practice during this time. Data were collected prospectively on all patients undergoing MSL between December 2017 and December 2019, in a single breast unit. Data were gathered retrospectively on patients who had undergone localised breast procedures between January 2016 and December 2019 for comparison of re-excision rates.

RESULTS

Two hundred and fifty-five patients underwent MSL surgery between December 2017 and December 2019. Of those, 98% (n=250) patients underwent successful MSL at the first attempt. The Magseed was identified intraoperatively in 100% patients and surgical excision was performed. The re-excision rate reduced from 18.9% in 2016/2017, to 11.6% in 2018/2019 (p=0.098).

CONCLUSION

In conclusion, Magseed localisation has proved to be a safe and effective way of localising breast lesions, with the advantage of high accuracy. The reduction in re-excision rates at University Hospital Crosshouse with the introduction of Magseed® localisation is a potential benefit, which requires further study.

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.

Magnetic Seed (Magseed) Localisation in Breast Cancer Surgery: A Multicentre Clinical Trial

INTRODUCTION

The aim of this study was to evaluate the accuracy and reliability of the Magseed magnetic marker in breast cancer surgery.

METHODS

Thirty-nine patients with 41 implanted Magseeds undergoing surgical treatment in 3 surgical oncology departments were included in the retrospective trial to study pilot use of the Magseed magnetic marker in the Czech Republic for localisation of breast tumours or pathological axillary nodes in breast cancer patients.

RESULTS

Thirty-four breast cancer and 7 pathological lymph node localisations were performed by Magseed implantation. No placement failures, or perioperative detection failures of Magseeds were observed (0/41, 0.0%), but one case of Magseed migration was present (1/41, 2.4%). All magnetic seeds were successfully retrieved (41/41, 100.0%). Negative margins were achieved in 29 of 34 (85.3%) breast tumour localisations by Magseed.

CONCLUSION

Magseed is a reliable marker for breast tumour and pathological axillary node localisation in breast cancer patients. Magseed is comparable to conventional localisation methods in terms of oncosurgical radicality and safety.

Preoperative non-palpable breast lesion localization, innovative techniques and clinical outcomes in surgical practice: A systematic review and meta-analysis

Pre-operative localization of non-palpable breast lesions with non-wired non-ionizing (NWNI) techniques may improve clinical outcomes as reoperation rate, cosmetic outcome and contribute to organizational aspects improvement in breast-conserving surgery (BCS). However only limited literature is available and clinical studies involving these forefront devices are often small and non-randomized. Furthermore, there is a lack of consensus on free margins and cosmetic outcomes definitions. The objective of the present meta-analysis was to determine the crude clinical outcomes reported for the NWNI techniques on BCS. A literature search was performed of PubMed, Embase and Scopus databases up to February 2021 in order to select all prospective or retrospective clinical trials on pre-operative breast lesion localization done with NWNI devices. All studies were assessed following the PRISMA recommendations. Continuous outcomes were described in averages corrected for sample size, while binomial outcomes were described using the weighted average proportion. Twenty-seven studies with a total of 2103 procedures were identified. The technique is consolidated, showing for both reflectors' positioning and localization nearly the 100% rate of success. The re-excision and clear margins rates were 14% (95% CI, 11-17%) and 87% (80-92%), respectively. Overall, positive margins rates were 12% (8-17%). In studies that compared NWNI and wire localization techniques, positive margin rate is lower for the first techniques (12%, 6-22% vs 17%, 12-23%) and re-excision rate is slightly higher using the latter (13%, 9-19% vs 16%, 13-18%). Pre-operative NWNI techniques are effective in the localization of non-palpable breast lesions and are promising in obtaining clear (or negative) margins minimizing the need for re-excision and improving the cosmetic outcomes. Randomized trials are needed to confirm these findings.

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.

Initial experience of magnetic seed localization for impalpable breast lesion excision: First 100 cases performed in a single Irish tertiary referral centre

INTRODUCTION

Wire guided localization has been widely utilized as the standard method of pre-operative localization of breast lesions. Magnetic seeds were developed to counter some of the disadvantages associated with wires. This aim of this study was to assess outcomes following the introduction of magnetic seeds at a tertiary specialist breast centre.

METHODS

A retrospective review of a prospective database of the first 100 patients who underwent magnetic seed (Magseed) guided breast surgery between November 2018 and November 2019. Data was collected from 17 wire guided cases completed during the trial phase for comparison. The primary outcome measures were successful excision of index lesion and retrieval of the magnetic seed. Secondary outcomes analyzed included time ready for theatre, post-operative complications and breast margin re-excision rate.

RESULTS

Of these 100 cases, 85 patients underwent Magseed guided wide local excision for invasive or in-situ carcinoma and 15 underwent Magseed guided diagnostic excision. The primary lesion was excised, and Magseed was retrieved in all 100 cases. 54% of patients were ready to proceed as the first scheduled theatre case of the day, compared to 0% of wire-guided cases. Amongst therapeutic Magseed guided cases, the re-excision rate for margin clearance was 9.4%.

CONCLUSION

Magseed guided breast excision is a new technology that has been implemented with relative ease in our unit. We have shown that magnetic seed guided surgery reliably localizes lesions, is associated with low re-excision rates without an increase in patient morbidity or mortality and results in improvements in theatre planning and efficiency.

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.

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

OBJECTIVE

A prospective, phase IV study was conducted to assess the effectiveness of Magseed to localize breast lesions requiring surgical excision.

BACKGROUND

Since FDA approval in 2016, Magseed has been increasingly used to localize non-palpable lesions due to advantages over wires or radioactive seeds. This is the first prospective, post marketing trial of Magseed.

METHODS

From 1/2017-2/2018, 107 women with lesions requiring localization were enrolled at a single institution. Primary endpoint was Magseed retrieval rate. Secondary endpoints were adverse events, accuracy of placement, surgery duration and positive margin rate. Clinicians were surveyed for ease of use using a Likert scale. Descriptive statistics and Fisher's exact test were performed to assess univariable associations with positive margins.

RESULTS

There were 124 Magseeds placed including one marker in 93 subjects, 2 markers in 11 and 3 markers in 3. The majority of lesions were masses (63%) followed by calcifications (24%). All 124 Magseeds were placed within 10mm of the target lesion and surgically retrieved with median operative time of 15min (range 4-47). No device-related adverse events occurred. Of the 98 malignant lesions, 9 had positive margins and 7 of them underwent a second surgery for additional margins. On univariable analysis, age ≤ 50 (25.0% vs 6.4%, p=0.04), lesion histology (p = 0.03), and pathologic T-stage (p = 0.04) were significantly associated with positive margins. Clinicians rated the Magseed very or fairly easy to use in most cases.

CONCLUSIONS

The Magseed system for localization of non-palpable lesions was effective and safe; all markers were successfully retrieved with margin-negative resections in 91%. This study supports use of Magseed for localization of breast lesions.

Advantages of preoperative localization and surgical resection of metastatic axillary lymph nodes using magnetic seeds after neoadjuvant chemotherapy in breast cancer

PURPOSE

To assess the safety and effectiveness of magnetic seeds in preoperative localization and surgical dissection of metastatic axillary lymph nodes (LN+) in breast cancer patients with axillary involvement, after neoadjuvant chemotherapy (NAC). In addition, to assess the impact of targeted axillary dissection (TAD) in reducing the rate of false negatives (FN) in sentinel lymph node biopsy (SLNB).

MATERIALS AND METHODS

A cross-sectional prospective cohort study was conducted from April 2017 to September 2019, including breast cancer patients with axillary lymph node involvement treated with NAC. Prior to NAC, the LN+ were marked by ultrasound-guided clip insertion. After NAC, a magnetic seed (Magseed®) was inserted in the clip-marked lymph node (MLN). During surgery, the MLN was located and removed with the aid of a magnetic detection probe (Sentimag®) and the sentinel lymph node was removed. Axillary lymph node dissection (ALND) was used to determine the rate of FN for SLNB alone and the combination of SLNB and MLN dissection, called TAD.

RESULTS

The study included 29 patients (mean age, 55; range, 30-78 years). Selective preoperative localization and surgical dissection were successful for all 30 MLNs (100%). The MLN corresponded to the SLN in 50% of cases. After ALND, there were 21.4% (3/14) FN with SLNB alone and 5.9% (1/17) with TAD.

CONCLUSIONS

Following NAC, selective surgical removal of MLN by preoperative localization using magnetic seeds is a safe and effective procedure with a success rate of 100%. Adding TAD reduces the rate of FN associated with SLNB alone.

Retrospective Review of Preoperative Radiofrequency Tag Localization of Breast Lesions in 848 Patients

BACKGROUND. Advantages of radiofrequency tags for preoperative breast lesion localization include decoupling of tag placement from surgical schedules and improved patient comfort. OBJECTIVE. The purpose of this study was to evaluate the feasibility of a preoperative localization radiofrequency tag system for breast lesions requiring surgical excision. METHODS. The cohort for this retrospective study included consecutive patients who underwent image-guided needle localization with radiofrequency tags before surgical excision from July 12, 2018, to July 31, 2019. Images and medical records were reviewed to evaluate the pathologic diagnoses serving as indications for tag placement, imaging guidance for tag placement, number of tags placed, and target lesion type. Tag placement technical accuracy rate (defined as deployment of the tag within 1 cm of the edge of the target), success (defined as technical accuracy without complication), and surgical margin and reexcision status were evaluated. RESULTS. A total of 1013 tags were placed under imaging guidance in 848 patients (mean age, 60 years; range, 23-96 years) and 847 subsequently underwent surgical excision. Tags were most commonly placed for invasive carcinoma (537/1013, 53.0%), ductal carcinoma in situ (138/1013, 13.6%), and high-risk lesions (289/1013, 28.5%). A total of 673 (66.4%) tags were deployed under mammographic guidance, whereas 340 (33.6%) were placed under sonographic guidance. Two or more tags were placed in 149 of 848 patients (17.6%). Targeted lesion types primarily included masses (448/1013, 44.2%), biopsy clip markers (331/1013, 32.7%), and calcifications (155/1013, 15.3%). Technical accuracy of placement was achieved in 1004 (99.1%) tags. Of the nine inaccurate tag placements, seven (77.8%) required an additional tag or wire placement. Seven (0.7%) biopsy clip markers were displaced within the breast or removed by the tag device during placement. No complications were reported intraoperatively. Therefore, success was achieved in 997 (98.4%) tags. Tags were successfully retrieved in all 847 patients who underwent surgery. Of the 568 patients with a preoperative diagnosis of carcinoma, 86 (15.1%) had positive or close surgical margins requiring surgical reexcision. CONCLUSION. Preoperative image-guided localization with radiofrequency tags is a safe and feasible technique for breast lesions requiring surgery. CLINICAL IMPACT. Radiofrequency tag localization is an acceptable alternative to needle or wire localization, offering the potential for improved patient workflow and experience.

Patient and clinician satisfaction and clinical outcomes of Magseed compared with wire-guided localisation for impalpable breast lesions

Background

Guide-wire localisation remains the most commonly used technique for localisation of impalpable breast lesions in the UK. One alternative is magnetic seed localisation. We aimed to investigate patient and clinician satisfaction in two consecutive cohorts, describe re-excision and positive margin rates, and explore reasons for positive margins and the implications for localisation techniques.

Methods

A single-institution prospective service evaluation of two cohorts of consecutive cases of wire and then Magseed localisation was carried out. Data were collected on patient and clinician satisfaction, clinico-pathological findings, and causes of involved margins. T tests were used to compare continuous variables and Chi-squared test for satisfaction outcomes.

Results

168 consecutive cases used wire-guided localisation (WGL) and 128 subsequent cases used Magseeds. Patients reported less anxiety between localisation and surgery in the Magseed group, and clinicians reported greater ease of use of Magseeds. There were no differences in lesion size, surgical complexity, or re-excision rate between the groups. In a subset of patients receiving standard wide local excision (i.e., excluding mammoplasties), the impact on margin involvement was investigated. There was no significant difference in radiological under-sizing or accuracy of localisation. However, specimen weight and eccentricity of the lesion were statistically significantly lower in the Magseed group. Despite this, re-excision rates were not significantly different (p = 0.4).

Conclusions

This is the first large study of satisfaction with localisation and showed clinician preference for Magseed and a reduction in patient anxiety. It also demonstrated similar positive margin rates despite smaller specimen weights in the Magseed group. Magnetic seed localisation offers an acceptable clinical alternative to guide wire localisation. The impact on local service provision should also be considered.

A decade of intraoperative ultrasound guided breast conservation for margin negative resection - Radioactive, and magnetic, and Infrared Oh My…

BACKGROUND

The oncologic goal of margin-negative breast conservation requires adequate localization of tumor. Intraoperative ultrasound remains most feasible but under-utilized method to localize the tumor and assess margins.

METHODS

A prospectively maintained breast cancer database over a decade was queried for margin status in breast cancer patients undergoing breast conservation. Techniques of tumor localization, margin re-excision and closest margins were analyzed. Rate of conversion to mastectomy was determined.

RESULTS

Of the 945 breast cancer patients treated at a university-based Breast Center of Excellence between January 1, 2009 and December 31, 2018, 149(15.8%) had ductal carcinoma in situ; 712(75.3%) had invasive ductal carcinoma, and 63(6.7%) had invasive lobular carcinoma. Clinical stage distribution was: T1 = 372(39.4%); T2 = 257(27.2%); T3 = 87(9.2%). Five hundred and eighty three (61.7%) patients underwent breast conservation. The median (25th -75th centile) closest margin was 6(2.5, 10.0) mm. Thirty five (6.0%) patients underwent margin re-excision, of which 9(25%) were converted to mastectomy. Tumor localization was achieved with ultrasound in 521(89.4%) patients and with wire localization in 62(10.6%) patients. The median (25th-75th centile) closest margin with wire localization was 5.0(2.0, 8.5) mm versus 5.0 (2.0, 8.0) mm with ultrasound guidance [p = 0.6635]. The re-excision rate with wire localization was 14.5% versus 4.9% with ultrasound guidance [p = 0.0073]. The unadjusted Odds Ratio (95% CI) for margin revision in wire localized group compared with ultrasound was 3.2 (7.14, 1.42) [p = 0.0045]; multivariate adjusted OR (95%) was 4(9.09, 1.7) [p = 0.0013].

CONCLUSIONS

Ultrasound guidance for localization of breast cancer remains the most effective option for margin negative breast conservation.

Node-Positive Patients Treated with Neoadjuvant Chemotherapy Can Be Spared Axillary Lymph Node Dissection with Wireless Non-Radioactive Localizers

BACKGROUND

Targeted axillary dissection (TAD) involves sentinel lymph node biopsy (SLNB) and excision of a biopsy-proven node marked by a clip. This study evaluates the feasibility of non-radioactive wireless localizers for targeted excision of clipped axillary lymph nodes.

METHODS

We identified biopsy-proven, node-positive breast cancer patients treated with neoadjuvant therapy (NAT) and TAD from 2016 to 2020, and included those with a clipped node localized using SAVI SCOUT, Magseed, or RFID Tag. Primary outcome measures were (1) successful localization (ultrasound or mammographic-guided placement < 10 mm from target), and (2) retrieval of the clipped node during TAD, documented by specimen radiography or gross visualization. Secondary outcomes included rates of completion axillary lymph node dissection (cALND) and complications.

RESULTS

Overall, 57 patients were included; 1 (1.8%) patient had no clip visible at the time of localization, and no radiographic confirmation of clip placement at the time of biopsy, and was therefore excluded. In the remaining 56 patients, localization was successful in 53 (94.6%) patients and the clipped node was retrieved during TAD in 51 (91.1%) patients. Twenty-three of 27 (85.2%) ypN0 patients were spared cALND; 3 (11.1%) patients had cALND for failed clipped node retrieval during TAD, and 1 (3.7%) for false-positive frozen section. In patients with TAD alone, the rates of axillary seroma and infection were 20.0% and 8.6%, respectively.

CONCLUSIONS

Wireless non-radioactive localizers are feasible for axillary localization after NAT, with high success rates of retrieving clipped nodes. The lack of signal decay is an advantage of these devices, allowing flexibility in timing of placement.

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

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.

CT-Guided Seed Localization in the Breast and Axilla

OBJECTIVE. The purpose of this study was to review preoperative CT-guided seed localization in the breast and axilla performed at my institution for lesions not visualized on routine mammography and ultrasound after neoadjuvant chemotherapy. CONCLUSION. Ten lesions (seven in the axilla, two in the breast, and one in the supraclavicular region) were localized with a radioactive seed under CT guidance. All were successfully excised at surgery, suggesting that CT guidance can be used when needle localization is not feasible using mammography or sonography.

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

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.