Feasibility of magnetic marker localisation for non-palpable breast cancer

Results of shared learning of a new radiofrequency identification localization device-a UK iBRA-NET breast cancer localisation study

INTRODUCTION

Localisation methods for surgical excision of impalpable breast lesions have advanced in recent years, with increasing utilization of new wire-free technologies. The Hologic LOCalizer™ radiofrequency identification (RFID) tag is one such device; however, as is the case when new technologies are first introduced, little is known about clinical experiences, potential complications, and learning used to overcome perioperative challenges when changing from guidewires to RFID tags. This study reports shared learning experiences of clinicians using the LOCalizer™ as part of the national iBRA-NET localisation study.

METHODS

This mixed-methods study captured shared-learning themes relating to LOCalizer™ usage as part of a multicentre prospective registry study, which collected data on each LOCalizer™ placement. Prospective, anonymized clinical and demographic data were collected and managed using a Research Electronic Data Capture (REDCap) database. Shared learning was captured prospectively as part of the registry study between January 2021 and July 2022, combined with a virtual qualitative webinar-style focus group. Learning events were then coded, grouped by theme, and suggestions for practice were produced.

RESULTS

Twenty-four UK breast units submitted data on 1188 patient records pertaining to RFID-guided localisation between January 2021 and July 2022, of which 59 (5.0%) included a shared-learning event. The virtual webinar was attended by 108 healthcare professionals, including oncoplastic breast surgeons and breast radiologists. Shared-learning themes were categorized into preoperative, intraoperative, and postoperative events.

CONCLUSIONS

By sharing learning outcomes associated with localisation techniques in this paper, the aim is to shorten the learning curve and potential for adverse events for users new to the LOCalizer™ technique.

Reliability of Magseed® marking before neoadjuvant systemic therapy with subsequent contrast-enhanced mammography in patients with non-palpable breast cancer lesions after treatment: the MAGMA study

PURPOSE

To assess the reliability of excising residual breast cancer lesions after neoadjuvant systemic therapy (NAST) using a previously localized paramagnetic seed (Magseed®) and the subsequent use of contrast-enhanced spectral mammography (CESM) to evaluate response.

METHODS

Observational, prospective, multicenter study including adult women (> 18 years) with invasive breast carcinoma undergoing NAST between January 2022 and February 2023 with non-palpable tumor lesions at surgery. Radiologists marked tumors with Magseed® during biopsy before NAST, and surgeons excised tumors guided by the Sentimag® magnetometer. CESMs were performed before and after NAST to evaluate tumor response (Response Evaluation Criteria for Solid Tumors [RECIST]). We considered intraoperative, surgical, and CESM-related variables and histological response.

RESULTS

We analyzed 109 patients (median [IQR] age of 55.0 [46.0, 65.0] years). Magseed® was retrieved from breast tumors in all surgeries (100%; 95% CI 95.47-100.0%) with no displacement and was identified by radiology in 106 patients (97.24%), a median (IQR) of 176.5 (150.0, 216.3) days after marking. Most surgeries (94.49%) were conservative; they lasted a median (IQR) of 22.5 (14.75, 40.0) min (95% CI 23.59-30.11 min). Most dissected tumor margins (93.57%) were negative, and few patients (5.51%) needed reintervention. Magseed® was identified using CESM in all patients (100%); RECIST responses correlated with histopathological evaluations of dissected tumors using the Miller-Payne response grade (p < 0.0001) and residual lesion diameter (p < 0.0001). Also 69 patients (63.3%) answered a patient's satisfaction survey and 98.8% of them felt very satisfied with the entire procedure.

CONCLUSION

Long-term marking of breast cancer lesions with Magseed® is a reliable and feasible method in patients undergoing NAST and may be used with subsequent CESM.

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%.

Magnetic seed localization is feasible for non-palpable melanoma, Merkel cell carcinoma, and soft tissue sarcoma lesions

BACKGROUND

Localization of non-palpable melanoma, Merkel cell carcinoma (MCC) and soft tissue sarcoma (STS) lesions can be difficult due to size, location, and obesity of patients or fibrosis due to previous treatments. Magnetic seed localization (MSL) is a common method to localize non-palpable breast lesions, but the feasibility of MSL for non-palpable melanoma, MCC and STS lesions has not yet been described.

METHODS

In this retrospective single center cohort study, all consecutive patients between January 2021 and October 2023 who had a resection of a non-palpable melanoma, MCC or STS lesion guided by Sirius Pintuition, a MSL technique, were included. The primary endpoint was successful lesion localization during surgery and the secondary endpoints were seed migration, negative resection margins, and complications.

RESULTS

Seventy-nine seeds were placed for 76 lesions, which were resected during 68 surgeries in 61 patients. All lesions (100 %) were localized and resected. Median time of surgery was 44 min. No seed migration was observed. A negative resection margin was achieved for 60 (78.9 %) lesions. Clavien Dindo grade ≥2 complications occurred in 7.4 %.

CONCLUSION

Magnetic seed localization with Sirius Pintuition is feasible for both non-palpable melanoma, MCC, and STS lesions.

Oncoplastic Breast-Conserving Surgery in African Women: A Systematic Review

PURPOSE

Breast cancer is the most frequently diagnosed cancer in women worldwide. Surgery is a major treatment modality for breast cancer, and over the years, breast-conserving surgeries with breast radiation have shown similar outcomes with mastectomy. Not much is known about the frequency and outcome of breast-conserving surgery in Africa. This systematic review provides a comprehensive summary of the evidence evaluating cosmetic and oncologic outcomes after oncoplastic breast-conserving surgery (OBCS) for breast cancer in African women.

METHODS

This review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Databases were systematically searched for studies on African women undergoing OBCS. The oncologic and cosmetic outcomes, as well as the localization and reconstruction techniques, were evaluated. Descriptive statistics were used to summarize the frequency and proportions of the extracted variables.

RESULTS

The literature search yielded 266 articles but only 26 of these were included in the review. Majority of the studies were from Egypt and South Africa. These studies collectively evaluated 1,896 patients with a mean age of 48.2 years and a mean follow-up period of 36.9 months. The most common histopathology was T2 (71.4%) invasive ductal carcinoma. Hook wire localization was the most common technique used for nonpalpable lesions in 85.3% of patients. Of the studies reporting oncoplastic technique, the latissimus dorsi volume replacement technique was the most reported (15%). Most patients were satisfied with their cosmetic outcome. Seroma was the most common postoperative complication (44.6%). Among studies that reported oncologic outcome data, the crude overall survival and disease-free survival were 93.1% and 89.4%, respectively.

CONCLUSION

This systematic review revealed that the outcome of OBCS in African women compares with that in developed countries.

3D magnetic seed localization for augmented reality in surgery

PURPOSE

For tumor resection, surgeons need to localize the tumor. For this purpose, a magnetic seed can be inserted into the tumor by a radiologist and, during surgery, a magnetic detection probe informs the distance to the seed for localization. In this case, the surgeon still needs to mentally reconstruct the position of the tumor from the probe's information. The purpose of this study is to develop and assess a method for 3D localization and visualization of the seed, facilitating the localization of the tumor.

METHODS

We propose a method for 3D localization of the magnetic seed by extending the magnetic detection probe with a tracking-based localization. We attach a position sensor (QR-code or optical marker) to the probe in order to track its 3D pose (respectively, using a head-mounted display with a camera or optical tracker). Following an acquisition protocol, the 3D probe tip and seed position are subsequently obtained by solving a system of equations based on the distances and the 3D probe poses.

RESULTS

The method was evaluated with an optical tracking system. An experimental setup using QR-code tracking (resp. using an optical marker) achieves an average of 1.6 mm (resp. 0.8 mm) 3D distance between the localized seed and the ground truth. Using a breast phantom setup, the average 3D distance is 4.7 mm with a QR-code and 2.1 mm with an optical marker.

CONCLUSION

Tracking the magnetic detection probe allows 3D localization of a magnetic seed, which opens doors for augmented reality target visualization during surgery. Such an approach should enhance the perception of the localized region of interest during the intervention, especially for breast tumor resection where magnetic seeds can already be used in the protocol.

Low-Cost Radio-Opaque Tumor Marking Techniques for Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy: a Systematic Review

Current standard of care localization techniques used in breast conserving surgery (BCS) after neoadjuvant chemotherapy (NACT) are expensive and may not be available in LMICs (lower-middle income countries). This review evaluated the efficacy of radio-opaque low-cost tumor markers. A systematic search was conducted as per PRISMA guidelines through November 30, 2022, for all studies using non-commercial radio-opaque tumor markers for patients undergoing BCS post NACT. Rate of unsatisfactory margin on final histology was the primary outcome. Oxford Centre for Evidence Based Medicine (OCEBM) levels were used to assess internal validity. After screening, 07 studies were included for data synthesis. For marking, four studies used LIGA clips, two used 5-mm cut pieces of K-wire, and one used cut pieces of 25-G needle. Incidence of unsatisfactory margins (positive/close) ranged from 0 to 11%. All studies found these low-cost markers to be feasible, with 100% pre-surgery visibility and 100% retrieval rate. Low-cost radio-opaque tumor markers (LIGA clips, 5-mm cut pieces of K-wire and 25-G needle) are effective methods of tumor localization especially for LMICs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13193-023-01845-2.

Wire- and radiofrequency identification tag-guided localization of impalpable breast lesions: iBRA-NET localization study

A national cohort ideal stage 2a/2b study comparing the safety and effectiveness of Wire- and RFID -guided localisation for impalpable breast lesions.

Radio-Guided Occult Lesion Localization With 99m Tc for the Localization of Nonpalpable Melanoma and Soft Tissue Sarcoma Lesions: A Feasibility Study

PURPOSE OF THE REPORT

Localization techniques are needed to facilitate resection of nonpalpable lesions. In this study, the feasibility of radio-guided occult lesion localization (ROLL) with 99m Tc is investigated for the localization of nonpalpable, small, suspicious, or proven melanoma or soft tissue sarcoma lesions at various locations throughout the body.

PATIENTS AND METHODS

Patients with nonpalpable, suspicious, or proven melanoma or soft tissue sarcoma lesions were selected for this study. Within 24 hours before surgery, a median dose of 33.92 MBq 99m Tc-labeled human albumin particles ( 99m Tc-NA or 99m Tc-MAA) was injected in the lesion under ultrasound guidance. A hand-held gamma probe was used to detect the radioactive signal and guidance during surgery.

RESULTS

In this study, 20 patients with a total of 25 lesions were included and analyzed. The median size of the lesions was 1.8 cm (interquartile range [IQR], 1.8-4.0 cm), of which 44% were intramuscular located and 36% were subcutaneous, and 20% consisted of suspicious lymph nodes, mostly in the lower extremity. At median 4 hours (IQR, 3-6 hours) postinjection, 99m Tc ROLL showed a 100% intraoperative identification rate with proper signal identification with the gamma probe in all patients. With a median surgery time of 76 minutes (IQR, 45-157 minutes), all targeted lesions could be resected without 99m Tc-related complications, resulting in 88% microscopically margin-negative resection. No reoperations were needed for the same lesion.

CONCLUSIONS

The 99m Tc ROLL procedure is feasible for the localization and excision of small, nonpalpable melanoma and soft tissue sarcoma lesions at various locations in the body.

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.

Comparison of 3 Different Systems for Non-wire Localization of Lesions in Breast Cancer Surgery

PURPOSE

Localizing breast lesions by marking tumors and their detection using probes during surgery is a common part of clinical practice. Various nonwire localization systems were intended to be compared from different perspectives.

METHODS

Various measurement experiments were performed. Localization techniques, including radioactive seed (RSLS), magnetically guided (MGLS), or radar (SLS), were compared in signal propagation in water and tissue environments, signal interference by surgical instruments, and the practical experience of surgeons. Individual experiments were thoroughly prospectively planned.

RESULTS

The RSLS signal was detectable at the largest evaluated distance, ie, 60 mm. The SLS and MGLS signal detection was shorter, up to 25 mm to 45 mm and 30 mm, respectively. The signal intensity and the maximum detection distance in water differed slightly depending on the localization marker orientation to the probe, especially for SLS and MGLS. Signal propagation in the tissue was noted to a depth of 60 mm for RSLS, 50 mm for SLS, and 20 mm for MGLS. Except for the expected signal interferences by approaching surgical instruments from any direction for MGLS, the signal interruption for RSLS and SLS was observed only by inserting instruments directly between the localization marker and probe. Moreover, the SLS signal interference by instrument touch was noted. Based on surgeons' results, individual systems did not differ significantly for most measurement condition settings.

CONCLUSION

Apparent differences noted among localization systems can help experts choose an appropriate system for a specific situation or reveal small nuances that have not yet been observed in clinical practice.

Image-Guided Localization Techniques for Metastatic Axillary Lymph Nodes in Breast Cancer; What Radiologists Should Know

Targeted axillary dissection (TAD) is an axillary staging technique after NACT that involves the removal of biopsy-proven metastatic lymph nodes in addition to sentinel lymph node biopsy (SLNB). This technique avoids the morbidity of traditional axillary lymph node dissection and has shown a lower false-negative rate than SLNB alone. Therefore, marking positive axillary lymph nodes before NACT is critical in order to locate and remove them in the subsequent surgery. Current localization methods include clip placement with intraoperative ultrasound, carbon-suspension liquids, localization wires, radioactive tracer-based localizers, magnetic seeds, radar reflectors, and radiofrequency identification devices. The aim of this paper is to illustrate the management of axillary lymph nodes based on current guidelines and explain the features of axillary lymph node markers, with relative advantages and disadvantages.

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.

Retrospective Cohort Study of Practical Applications of Paramagnetic Seed Localisation in Breast Carcinoma and Other Malignancies

(1) Background: Paramagnetic seeds are a safe alternative for the wire-guided localisation of non-palpable breast lesions, but can also be applied for non-breast lesions. This study presents the experience with a paramagnetic seed, MagSeed® (Endomagnetics Ltd., Cambridge, UK, CE-registered and FDA-cleared), in an academic and non-academic breast centre. (2) Methods: Multicentre, retrospective analysis of 374 consecutive patients who underwent surgery after paramagnetic seed localisation (MSL) between 2018 and 2020. Indications for localisation included non-palpable breast lesions (n = 356), lymph nodes (n = 15) or soft tissue lesions (n = 3). The primary outcome was feasibility and the rate of positive section margins. The secondary outcome was predictive factors for positive section margins. (3) Results: The accurate excision of high-risk breast lesions, lymph nodes and soft tissue lesions was seen in 91.07% (n = 56). Positive section margins were observed in 7.86% (n = 25) after breast conserving surgery for invasive or ductal carcinoma in situ (DCIS) (n = 318). Invasive breast cancer associated with DCIS (p = 0.043) and the size of DCIS (p < 0.001) were significantly correlated with the positive section margins. (4) Conclusion: This study confirms the feasibility of MSL, as well as the higher risk for positive margins in cases of breast carcinoma with associated DCIS. Soft tissue lesions and lymph nodes associated with other malignancies, e.g., melanoma, can also be localised with paramagnetic seeds. This offers perspectives for future applications, such as the de-escalation of axillary treatment in breast cancer.

Results of shared learning of a new magnetic seed localisation device - A UK iBRA-NET breast cancer localisation study

INTRODUCTION

Shared learning is imperative in the assessment and safe implementation of new healthcare interventions. Magnetic seeds (Magseed®) potentially offer logistical benefit over wire localisation for non-palpable breast lesions but few data exist on outcomes comparing these techniques. A national registration study (iBRA-NET) was conducted to collate device outcomes. In order to share learning, thematic analysis was conducted to ascertain early clinical experiences of Magseed® and wire guided localisation and explore how learning events may be applied to improve clinical outcomes.

METHODS

A qualitative study of 27 oncoplastic surgeons, radiologists and physicians was conducted in January 2020 to ascertain the feasibility and challenges associated with Magseed® versus wire breast localisation surgery. Four focus groups were asked to discuss experiences, concerns and shared learning outcomes which were tabulated and analysed thematically.

RESULTS

Three key themes were identified comparing Magseed® and wire localisation of breast lesions relating to preoperative, intraoperative and postoperative learning outcomes. Percutaneous Magseed® detection, instrument interference and potential seed or wire dislodgement were the most common issues identified. Clinician experience suggested Magseed® index lesion identification was non-inferior to wire placement and improved the patient pathway in terms of scheduling and multi-site insertion.

CONCLUSIONS

Prospective shared learning suggested Magseed® offered additional non-clinical benefits over wire localisation, improving the efficiency of the patient pathway. Recommendations for improving breast localisation technique, appropriate patient selection and clinical practice through shared learning are discussed that may aid other surgeons in the adoption of this relatively new technique.

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.

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.

A multicenter prospective cohort study to evaluate feasibility of radio-frequency identification surgical guidance for nonpalpable breast lesions: design and rationale of the RFID Localizer 1 Trial

BACKGROUND

Breast cancer screening and improving imaging techniques have led to an increase in the detection rate of early, nonpalpable breast cancers. For early breast cancer, breast conserving surgery is an effective and safe treatment. Accurate intraoperative lesion localization during breast conserving surgery is essential for adequate surgical margins while sparing surrounding healthy tissue to achieve optimal cosmesis. Preoperative wire localization and radioactive seed localization are accepted standard methods to guide surgical excision of nonpalpable breast lesions. However, these techniques present significant limitations. Radiofrequency identification (RFID) technology offers a new, nonradioactive method for localizing nonpalpable breast lesions in patients undergoing breast conserving surgery. This study aims to evaluate the feasibility of RFID surgical guidance for nonpalpable breast lesions.

METHODS

This multicenter prospective cohort study was approved by the Institutional Review Board of the University Medical Center Utrecht. Written informed consent is obtained from all participants. Women with nonpalpable, histologically proven in situ or invasive breast cancer, who can undergo breast conserving surgery with RFID localization are considered eligible for participation. An RFID tag is placed under ultrasound guidance, up to 30 days preoperatively. The surgeon localizes the RFID tag with a radiofrequency reader that provides audible and visual real-time surgical guidance. The primary study outcome is the percentage of irradical excisions and reexcision rate, which will be compared to standards of the National Breast Cancer Organisation Netherlands (NABON)(≤ 15% irradical excisions of invasive carcinomas). Secondary outcomes include user acceptability/experiences, learning curve, duration and ease of the placement- and surgical procedure and adverse events.

DISCUSSION

This study evaluates the feasibility of RFID surgical guidance for nonpalpable breast lesions. Results may have implications for the future localization techniques in women with nonpalpable breast cancer undergoing breast conserving surgery.

TRIAL REGISTRATION

Netherlands National Trial Register, NL8019 , registered on September 12^th 2019.

Wire- and magnetic-seed-guided localization of impalpable breast lesions: iBRA-NET localisation study

BACKGROUND

Wire localization is historically the most common method for guiding excision of non-palpable breast lesions, but there are limitations to the technique. Newer technologies such as magnetic seeds may allow some of these challenges to be overcome. The aim was to compare safety and effectiveness of wire and magnetic seed localization techniques.

METHODS

Women undergoing standard wire or magnetic seed localization for non-palpable lesions between August 2018 and August 2020 were recruited prospectively to this IDEAL stage 2a/2b platform cohort study. The primary outcome was effectiveness defined as accurate localization and removal of the index lesion. Secondary endpoints included safety, specimen weight and reoperation rate for positive margins.

RESULTS

Data were accrued from 2300 patients in 35 units; 2116 having unifocal, unilateral breast lesion localization. Identification of the index lesion in magnetic-seed-guided (946 patients) and wire-guided excisions (1170 patients) was 99.8 versus 99.1 per cent (P = 0.048). There was no difference in overall complication rate. For a subset of patients having a single lumpectomy only for lesions less than 50 mm (1746 patients), there was no difference in median closest margin (2 mm versus 2 mm, P = 0.342), re-excision rate (12 versus 13 per cent, P = 0.574) and specimen weight in relation to lesion size (0.15 g/mm2versus 0.138 g/mm2, P = 0.453).

CONCLUSION

Magnetic seed localization demonstrated similar safety and effectiveness to those of wire localization. This study has established a robust platform for the comparative evaluation of new localization devices.

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.

Multicentre evaluation of magnetic technology for localisation of non-palpable breast lesions and targeted axillary nodes

BACKGROUND

Magseed technology is a recently introduced localisation technique for impalpable breast lesions with possible advantages over traditional techniques. These include improved theatre logistics, flexibility in incision placement and improved patient experience. This multicentre study evaluates the experience of introducing Magseed technology into routine surgical practice.

METHODS

A prospective multicentre study of Magseed localised procedures was performed. Insertion data were recorded by the radiologist including lesion characteristics and Magseed insertion accuracy. The surgical team recorded time from insertion to operation, operating time and surgical satisfaction. Pathology results were reviewed for specimen weight and margins.

RESULTS

Between February 2019 and June 2020, 100 patients were enrolled. Magseed localised procedures included 18 excisional biopsies, 23 wide local excisions (WLE), 50 WLE with axillary surgery and four cases of Magseed localised breast WLE with Magseed localised axillary surgery. There were three therapeutic mammoplasties and two cases of Magseed localised targeted axillary node dissection alone. A total of 90% of Magseeds were radiologically placed within 5 mm of the target lesion/node. Time between incision and specimen removal was 17 min (range 6-40 min). All breast and axillary Magseeds were successfully identified and retrieved during surgery. The target lesion was identified in the specimen in all cases. A total of 10% of cases required further surgery for pathologically positive margins. Overall, surgeons reported that Magseed localisation was "easy" or "very easy" in 77% of cases.

CONCLUSION

Magseed is a reliable, safe and accurate surgical technique that provides logistical advantages and flexibility of surgical approach. The method was well-accepted by all users.

Impact of deformation on a supine-positioned image-guided breast surgery approach

PURPOSE

To reduce reoperation rates for image-guided breast-conserving surgery, the enhanced sensitivity of magnetic resonance (MR) supine imaging may be leveraged. However, accurate tissue correspondence between images and their physical counterpart in the surgical presentation is challenging due to breast deformations (e.g., from patient/arm position changes, and operating room table rotation differences). In this study, standard rigid registration methods are employed and tissue deformation is characterized.

METHODS

On n = 10 healthy breasts, surface displacements were measured by comparing intraoperative fiducial locations as the arm was moved from conventional MR scanning positions (arm-down and arm-up) to the laterally extended surgical configuration. Supine MR images in the arm-down and arm-up positions were registered to mock intraoperative presentations.

RESULTS

Breast displacements from a supine MR imaging configuration to a mock surgical presentation were 28.9 ± 9.2 mm with shifts occurring primarily in the inferior/superior direction. With respect to supine MR to surgical alignment, the average fiducial, target, and maximum target registration errors were 9.0 ± 1.7 mm, 9.3 ± 1.7 mm, and 20.0 ± 7.6 mm, respectively. Even when maintaining similar arm positions in the MR image and mock surgery, the respective averages were 6.0 ± 1.0 mm, 6.5 ± 1.1 mm, and 12.5 ± 2.8 mm.

CONCLUSION

From supine MR positioning to surgical presentation, the breast undergoes large displacements (9.9-70.1 mm). The data also suggest that significant nonrigid deformations (9.3 ± 1.7 mm with 20.0 mm average maximum) exist that need to be considered in image guidance and modeling applications.

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.

Randomized controlled trial comparing magnetic marker localization (MaMaLoc) with wire-guided localization in the treatment of early-stage breast cancer

Wire-guided localization (WGL) is the standard of care in the surgical treatment of nonpalpable breast tumors. In this study, we compare the use of a new magnetic marker localization (MaMaLoc) technique to WGL in the treatment of early-stage breast cancer patients. Open-label, single-center, randomized controlled trial comparing MaMaLoc (intervention) to WGL (control) in women with early-stage breast cancer. Primary outcome was surgical usability measured using the System Usability Scale (SUS, 0-100 score). Secondary outcomes were patient reported, clinical, and pathological outcomes such as retrieval rate, operative time, resected specimen weight, margin status, and reoperation rate. Thirty-two patients were analyzed in the MaMaLoc group and 35 in the WGL group. Patient and tumor characteristics were comparable between groups. No in situ complications occurred. Retrieval rate was 100% in both groups. Surgical usability was higher for MaMaLoc: 70.2 ± 8.9 vs. 58.1 ± 9.1, p < 0.001. Patients reported higher overall satisfaction with MaMaLoc (median score 5/5) versus WGL (score 4/5), p < 0.001. The use of magnetic marker localization (MaMaLoc) for early-stage breast cancer is effective and has higher surgical usability than standard WGL.

Magnetically Guided Localization Using a Guiding-Marker System® and a Handheld Magnetic Probe for Nonpalpable Breast Lesions: A Multicenter Feasibility Study in Japan

Simple Summary

In this multicenter feasibility study, non-palpable breast lesions in 89 patients were localized using a handheld cordless magnetic probe (TAKUMI) and a magnetic marker (Guiding-Marker System^®). Additionally, a dye was injected subcutaneously under ultrasound guidance to indicate the extent of the tumor. Consequently, a magnetic marker was detected in all resected specimens, and the initial surgical margin was positive only in five (6.1%) of 82 patients. Thus, the magnetic guiding localization system with ultrasound guidance is useful for the detection and excision of non-palpable breast lesions.

Abstract

Accurate pre-operative localization of nonpalpable lesions plays a pivotal role in guiding breast-conserving surgery (BCS). In this multicenter feasibility study, nonpalpable breast lesions were localized using a handheld magnetic probe (TAKUMI) and a magnetic marker (Guiding-Marker System^®). The magnetic marker was preoperatively placed within the target lesion under ultrasound or stereo-guidance. Additionally, a dye was injected subcutaneously to indicate the extent of the tumor excision. Surgeons checked for the marker within the lesion using a magnetic probe. The magnetic probe could detect the guiding marker and accurately localize the target lesion intraoperatively. All patients with breast cancer underwent wide excision with a safety margin of ≥5 mm. The presence of the guiding-marker within the resected specimen was the primary outcome and the pathological margin status and re-excision rate were the secondary outcomes. Eighty-seven patients with nonpalpable lesions who underwent BCS, from January to March of 2019 and from January to July of 2020, were recruited. The magnetic marker was detected in all resected specimens. The surgical margin was positive only in 5/82 (6.1%) patients; these patients underwent re-excision. This feasibility study demonstrated that the magnetic guiding localization system is useful for the detection and excision of nonpalpable breast lesions.

Reflector-Guided Localisation of Non-Palpable Breast Lesions: A Prospective Evaluation of the SAVI SCOUT® System

Simple Summary

Marking impalpable areas of breast cancer prior to surgery is an important part of the modern treatment of breast cancer. Traditionally, the target lesion would be marked by a wire just before surgery under image guidance and would help the surgeon locate the tumour during surgery. However, this method has some drawbacks, such as patient discomfort, the risk of migration and dislodgement, and the need to couple surgical and radiological schedules. Therefore, there has been a growing interest in this system, thus supporting its potential. In this study, we have evaluated one such system, SAVI SCOUT^®, in 63 consecutive patients. Our experience with this system supported its potential role in modern breast surgery.

Abstract

Wire-guided localisation (WGL) has been the mainstay for localising non-palpable breast lesions before excision. Due to its limitations, various wireless alternatives have been developed. In this prospective study, we evaluate the role of radiation-free wireless localisation using the SAVI SCOUT^® system at the London Breast Institute. A total of 72 reflectors were deployed in 67 consecutive patients undergoing breast conserving surgery for non-palpable breast lesions. The mean interval between deployment and surgery for the therapeutic cases was 18.8 days (range: 0–210). The median deployment duration was 5 min (range: 1–15 min). The mean distance from the lesion was 1.1 mm (median distance: 0; range: 0–20 mm). The rate of surgical localisation and retrieval of the reflector was 98.6% and 100%, respectively. The median operating time was 28 min (range: 15–55 min) for the therapeutic excision of malignancy and 17 min (range: 15–24) for diagnostic excision. The incidence of reflector migration was 0%. Radial margin positivity in malignant cases was 7%. The median weight for malignant lesions was 19.6 g (range: 3.5–70 g). Radiologists and surgeons rated the system higher than WGL (93.7% and 98.6%, respectively; 60/64 and 70/71). The patient mean satisfaction score was 9.7/10 (n = 47, median = 10; range: 7–10). One instance of signal failure was reported. In patients who had breast MRI after the deployment of the reflector, the MRI void signal was <5 mm (n = 6). There was no specific technique-related surgical complication. Our study demonstrates that wire-free localisation using SAVI SCOUT^® is an effective and time-efficient alternative to WGL with excellent physician and patient acceptance.

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.

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.

Wireless Breast Localization Using Radio-frequency Identification Tags: The First Reported European Experience in Breast Cancer

BACKGROUND/AIM

Wire-guided localisation (WGL) has been the mainstay for localisation of clinically occult breast lesions before excision. However, it has restrictive scheduling requirements, and causes patient discomfort. This has prompted the development of various wireless alternatives. In this prospective study we shall evaluate the role of radiation-free wireless localisation using a radiofrequency identification (RFID) tag and a hand-held reader (LOCalizer™) in the management of occult breast lesions.

PATIENTS AND METHODS

This technique was evaluated in a prospective cohort of 10 patients. The evaluation focused on: i) successful deployment, ii) identification and retrieval, iii) the status of surgical margins and need for re-operation, iv) resected specimen weight, v) marker migration rates (>5mm), and vi) acceptance by patients, radiologists and surgeons.

RESULTS

RFID tags (n=11) were deployed under ultrasound guidance pre-operatively to localise occult breast lesions in 10 patients. The mean time for deployment of the RFID tag was 5.4 min (range=2-20). The mean distance from the lesion was 0.45 mm (range=0-3). The mean duration for retrieval was 10.2 min (range=6-20). Mean specimen weight was 19.6 g for malignant lesions (range=4.5-42). All tags were identified, and none had migrated. There were no positive margins, re-operations, nor complications. Patient feedback was highly positive. Both radiologists and surgeons rated the LOCalizer™ technique as better than WGL.

CONCLUSION

Our study demonstrates that wireless localisation using RFID is an effective and time-efficient alternative to WGL, with low margin positivity and re-operation rates, and high patient, radiologist and surgeon acceptance.

Accuracy and feasibility of SentiMag technique for localization of non-palpable breast lesions

BACKGROUND

Non-palpable breast lesions are more frequent now than in the past due to the attention toward the mammary pathology and the screening diffusion; the marking of such lesions is very important for a successful surgery. The SentiMag System uses a magnetic marker that is inoculated transdermal in the breast through an 18-gauge needle.

METHODS

Between April 1^st and June 30^th, 2018, 16 patients with non-palpable breast lesions were selected and subjected to surgery using the SentiMag System in our Unit. They were women with a mean age of 52 years (range 30-84 years). Seven of 16 (43.7%) had a borderline preoperative histological or cytological diagnosis (C3/B3), and nine (56.3%) a diagnosis of carcinoma (C5/B5). Six (37.5%) were marked on ultrasound guidance and 10 (62.5%) on a mammography stereotaxic guide.

RESULTS

The time for the marker positioning ranged from 2 to 10 minutes. The radiological control of the surgical specimen always showed the presence of both the lesion and the marker, both centered within the specimen and intact. The pathology revealed seven benign lesions, one in-situ, and eight infiltrating carcinomas.

CONCLUSIONS

The SentiMag represents a fast and safe preoperative marking system of non-palpable breast lesions, cutting the radio exposure for personnel and patients. The marker is not displaced over time and it is rapid to place and easy to locate intraoperatively, allowing a clear dissection plane around the lesion. Thus, this reduces the amount of gland removed, improving the aesthetic result mostly in small breasts.

Early budget impact analysis on magnetic seed localization for non-palpable breast cancer surgery

INTRODUCTION

Current localization techniques used in breast conserving surgery for non-palpable tumors show several disadvantages. Magnetic Seed Localization (MSL) is an innovative localization technique aiming to overcome these disadvantages. This study evaluated the expected budget impact of adopting MSL compared to standard of care.

METHODS

Standard of care with Wire-Guided Localization (WGL) and Radioactive Seed Localization (RSL) use was compared with a future situation gradually adopting MSL next to RSL or WGL from a Dutch national perspective over 5 years (2017-2022). The intervention costs for WGL, RSL and MSL and the implementation costs for RSL and MSL were evaluated using activity-based costing in eight Dutch hospitals. Based on available list prices the price of the magnetic seed was ranged €100-€500.

RESULTS

The intervention costs for WGL, RSL and MSL were respectively: €2,617, €2,834 and €2,662 per patient and implementation costs were €2,974 and €26,826 for MSL and RSL respectively. For standard of care the budget impact increased from €14.7m to €16.9m. Inclusion of MSL with a seed price of €100 showed a budget impact of €16.7m. Above a price of €178 the budget impact increased for adoption of MSL, rising to €17.6m when priced at €500.

CONCLUSION

MSL could be a cost-efficient localization technique in resecting non-palpable tumors in the Netherlands. The online calculation model can inform adoption decisions internationally. When determining retail price of the magnetic seed, cost-effectiveness should be considered.

Percutaneous hook wire assistance during laparoscopic excision of an intrarenal mass

Completely endophytic renal tumours pose challenges in laparoscopic nephron-sparing tumour excisions, with the use of intraoperative imaging techniques (e.g. ultrasound) being crucial when managing such tumours. The use of a percutaneous hookwire for tumour localisations are in use in several other surgical fields, such as breast surgery. An asymptomatic 52-year-old man presented with an incidental small right sided solid 33-mm interpolar renal mass identified on computed tomography. A guided insertion of a percutaneous localisation wire was carried out prior to a laparoscopic partial nephrectomy to assist in intraoperative tumour landmark/margins identification. Operative time was 210 minutes with zero ischaemia time, with an estimated blood loss of 200 ml. No perioperative complications were observed and the patient was discharged two days postoperatively. Histology revealed the mass to be a Fuhrman grade 2 clear-cell carcinoma with a 2-mm clear surgical margin. The patient remained free of recurrence at 16 months of follow-up. We have reported our first experience of wire localisation prior to laparoscopic partial nephrectomy for an intrarenal mass, which to our knowledge could be the first of its kind in renal surgery. Percutaneous wire localisation of endophytic renal tumours is potentially safe and effective and can allow nephron-sparing surgery where laparoscopic ultrasound is not available. Longer-term and further evidence should be encouraged.

A Review of Options for Localization of Axillary Lymph Nodes in the Treatment of Invasive Breast Cancer

Invasive breast cancer is a common disease, and the most common initial site of metastatic disease are the axillary lymph nodes. As the standard of care shifts towards less invasive surgery in the axilla for patients with invasive breast cancer, techniques have been developed for axillary node localization that allow targeted dissection of specific lymph nodes without requiring full axillary lymph node dissection. Many of these techniques have been adapted from technologies developed for localization of lesions within the breast and include marker clip placement with intraoperative ultrasound, carbon-suspension liquids, localization wires, radioactive seeds, magnetic seeds, radar reflectors, and radiofrequency identification devices.The purpose of this article is to summarize these methods and describe benefits and drawbacks of each method for performing localization of lymph nodes in the axilla.

Surgical removal of the index node marked using magnetic seed localization to assess response to neoadjuvant immunotherapy in patients with stage III melanoma

This pilot study explored the value of localized index node removal after neoadjuvant immunotherapy in patients with stage III melanoma, for use as a response indicator to guide the extent of completion lymph node dissection. Promising technology.

Conservative Management of Positive Axilla After Neoadjuvant Systemic Therapy-The Need for, and Review of, Techniques Used for Lymph Node Localization

Involvement of axillary lymph nodes is an important prognostic factor in relationship to the management of breast cancer. However, the use of neoadjuvant systemic therapy is widespread in the treatment of positive axilla and such treatment leads to downstaging of axillary disease. Hence, the role of targeted axillary lymph node biopsy appears to play a vital role after primary systemic therapy. Given that this is a relatively novel approach, we have discussed the evidence for this approach and the different techniques currently available for localization of biopsy-proven metastatic axillary lymph nodes. We have also highlighted the need for universal guidelines for conservative management of positive axilla after systemic therapy.

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.

Targeted axillary dissection after neoadjuvant therapy in breast cancer

Enables de-escalation of surgery