Evaluation of Axillary Lymph Node Marking with Magseed® before and after Neoadjuvant Systemic Therapy in Breast Cancer Patients: MAGNET Study

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%.

Superparamagnetic iron oxide (SPIO) for sentinel lymph node detection in vulvar cancer

OBJECTIVES

Sentinel lymph node (SLN) detection with superparamagnetic iron oxide (SPIO) nanoparticles has been widely studied and standardized for breast and prostate cancer, but there is scarce evidence concerning its use in vulvar cancer. The objective of this study was to compare SLN detection using a SPIO tracer injected at the time of the surgery detected by a magnetometer, with the standard procedure of using a technetium 99 radioisotope (Tc99) detected by a gamma probe, in patients with vulvar cancer.

METHODS

The SPIO vulvar cancer study was a single-center prospective interventional non-inferiority study of SPIO compared to Tc99, conducted between 2016 and 2021 in patients who met the GROINSS-V study inclusion criteria for selective sentinel lymph node dissection in vulvar cancer.

RESULTS

We included 18 patients and a total of 41 SLNs. The level of agreement between tracers was 92.7% (80.6%-97.4%), corresponding to 38 out of 41 SLNs, which confirms the non-inferiority of SPIO compared to Tc99. The SLN detection rate per groin was 96.3 (81.7%-99.3) using Tc99 and 100% (87.5%-100%) using SPIO. Both tracers had a detection rate of 100% for positive lymph nodes.

CONCLUSIONS

The use of SPIO as a tracer for detecting SLNs in patients with vulvar cancer has shown to be non-inferior to that of the standard radiotracer, with the advantages of not requiring nuclear medicine and being able to inject it at the time of surgery after induction of anesthesia.

Evaluating Magnetic Seed Localization in Targeted Axillary Dissection for Node-Positive Early Breast Cancer Patients Receiving Neoadjuvant Systemic Therapy: A Comprehensive Review and Pooled Analysis

Background/Objectives: De-escalation of axillary surgery is made possible by advancements in both neoadjuvant systemic therapy (NST) and in localisation technology for breast lesions. Magseed®, developed in 2013 by Dr. Michael Douk of Cambridge, United Kingdom, is a wire-free localisation technology that facilitates the localisation and retrieval of lymph nodes for staging. Targeted axillary dissection (TAD), which entails marked lymph node biopsy (MLNB) and sentinel lymph node biopsy (SLNB), has emerged as the preferred method to assess residual disease in post-NST node-positive patients. This systematic review and pooled analysis evaluate the performance of Magseed® in TAD. Methods: The search was carried out in PubMed and Google Scholar. An assessment of localisation, retrieval rates, concordance between MLNB and SLNB, and pathological complete response (pCR) in clinically node-positive patients post NST was undertaken. Results: Nine studies spanning 494 patients and 497 procedures were identified, with a 100% successful deployment rate, a 94.2% (468/497) [95% confidence interval (CI), 93.7-94.7] localisation rate, a 98.8% (491/497) retrieval rate, and a 68.8% (247/359) [95% CI 65.6-72.0] concordance rate. pCR was observed in 47.9% (220/459) ) [95% CI 43.3-52.6] of cases. Subgroup analysis of studies reporting the pathological status of MLNB and SLNB separately revealed an FNR of 4.2% for MLNB and 17.6% for SLNB (p = 0.0013). Mean duration of implantation was 37 days (range: 0-188). Conclusions: These findings highlight magnetic seed localisation's efficacy in TAD for NST-treated node-positive patients, aiding in accurate axillary pCR identification and safe de-escalation of axillary surgery in excellent responders.

Efficacy of Targeted Axillary Dissection With Radar Reflector Localization Before Neoadjuvant Chemotherapy

INTRODUCTION

For clinically node positive breast cancer patients treated with neoadjuvant chemotherapy (NAC), targeted axillary dissection (TAD) can be used to stage the axilla. TAD removes the sentinel lymph node (SLN) and tagged positive nodes, which can be identified via radar reflector localization (RRL). As it can be challenging to localize a previously positive node after NAC, we evaluated RRL prior to NAC.

METHODS

We performed a retrospective chart review of breast cancer patients with node positive disease treated with NAC who underwent TAD with RRL. We compared retrieval of radar reflector and clip, timing of localization, and, if a node was positive, whether the radar reflector node or SLN was positive.

RESULTS

Seventy-nine patients fulfilled inclusion criteria; 32 were placed pre-NAC (mean 187 d before surgery) and 47 were placed post-NAC (mean 7 d before surgery). For pre-NAC placement, 31 of 32 radar reflectors and 31 of 32 clips were retrieved. For post-NAC placement, 47 of 47 radar reflectors and 46 of 47 clips were retrieved. There was no significant difference in radar reflector or clip retrieval rates between pre-NAC and post-NAC groups (P = 0.41, P = 1, respectively). Thirty of 32 patients with pathologic complete response avoided an axillary lymph node dissection. Of 47 patients with a positive lymph node, 32 were both the SLN and radar reflector node, 11 were radar reflector alone, and four were the SLN.

CONCLUSIONS

RRL systems are an effective way to guide TAD, and RRL makers can be safely placed prior to NAC.

[Can we avoid axillary lymph node dissection in patients with node positive invasive breast carcinoma?]

OBJECTIVES

The indications and modalities of breast and axillary surgery are undergoing profound change, with the aim of personalizing surgical management while avoiding over-treatment. To update best practices for axillary surgery, four questions were selected by the Senology Commission of the Collège National des Gynécologues et Obstétriciens Français (CNGOF), focusing on, firstly, the definition and evaluation of targeted axillary dissection (TAD) techniques; secondly, the possibility of surgical de-escalation in case of initial lymph node involvement while performing initial surgery; thirdly, in case of surgery following neo-adjuvant systemic therapy (NAST), and fourthly, contra-indications to de-escalation of axillary surgery to allow access to particular adjuvant systemic therapies.

METHODS

The Senology Commission based its responses primarily on an analysis of the international literature, clinical practice recommendations and national and international guidelines.

RESULTS

Firstly, TAD is a technique that combines excision of clipped metastatic axillary node(s) and the axillary sentinel lymph nodes (ASLNs). The detection rate and sensitivity are increased but it still needs to be standardized and practices better evaluated. Secondly, TAD represents an alternative to axillary clearance in cases of metastatic involvement of a single node that can be resected. Thirdly, neither TAD nor ASLN alone is recommended in France after NAST outside of clinical trials, although it is used in several countries in cases of complete pathological response in the lymph nodes, and when at least three lymph nodes have been removed. Fourthly, as some adjuvant targeted therapies are indicated in cases of lymph node invasion of more than three lymph nodes, the place of TAD in this context remains to be defined.

CONCLUSION

Axillary surgical de-escalation can limit the morbidity of axillary clearance. Having proved that TAD does not reduce patient survival, it will most probably replace axillary clearance in well-defined indications. This will require prior standardization of the method and its indications and contra-indications, particularly to enable the use of new targeted therapies.

Technetium-99-Guided Axillary Lymph Node Identification: A Case Report of a Novel Technique for Targeted Lymph Node Excision Biopsy for Node Positive Breast Cancer After Neoadjuvant Chemotherapy

Targeted axillary lymph node identification for breast cancer involves localization and removal of previously marked metastatic lymph nodes after the completion of neoadjuvant chemotherapy (NACT), when clinical and radiological complete responses of the axillary nodes are achieved. Traditionally, axillary lymph node dissection is performed for patients with node positive disease, but the high rates of pathological complete responses now seen after NACT have ushered in lower morbidity techniques such as sentinel lymph node excision biopsies, targeted axillary lymph node dissection and targeted axillary lymph node identification (clip node identification) in node positive disease which has converted to clinical/radiologically node negative. The latter two techniques often require the use of expensive seeds and advanced localization techniques. Here we describe the case of a 59-year-old woman who was diagnosed with node positive invasive breast cancer who was sequenced with NACT. We developed a novel technique, where technetium-99m was injected directly into a previously clipped metastatic axillary lymph node which was then localized with the Neoprobe gamma detection system intra-operatively and removed. This is a relatively low-cost technique that can be easily introduced in limited resourced health systems where radio-guided sentinel lymph node biopsies are already being performed.

Applicability of magnetic seeds for target lymph node biopsy after neoadjuvant chemotherapy in initially node-positive breast cancer patients: data from the AXSANA study

PURPOSE

Currently, various techniques are available to mark and selectively remove initially suspicious axillary lymph nodes (target lymph nodes, TLNs) in breast cancer patients receiving neoadjuvant chemotherapy (NACT). To date, limited data are available on whether the use of magnetic seeds (MS) is suitable for localizing TLNs. This study aimed to investigate the feasibility of MS in patients undergoing target lymph node biopsy (TLNB) or targeted axillary dissection (TAD) after NACT.

METHODS

Prospective data from the ongoing multicentric AXSANA study were extracted from selected patients in whom the TLN had been marked with an MS before NACT and who were enrolled from June 2020 to June 2023. The endpoints of the analysis were the detection rate, the rate of lost markers, and the potential impairment on magnetic resonance imaging (MRI) assessment.

RESULTS

In 187 patients from 27 study sites in seven countries, MS were placed into the TLN before NACT. In 151 of these, post-NACT surgery had been completed at the time of analysis. In 146 patients (96.0%), a TLN could successfully be detected. In three patients, the seed was removed but no lymphoid tissue was detected on histopathology. The rate of lost markers was 1.2% (2 out of 164 MS). In 15 out of 151 patients (9.9%), MRI assessment was reported to be compromised by MS placement.

CONCLUSION

MS show excellent applicability for TLNB/TAD when inserted before NACT with a high DR and a low rate of lost markers. Axillary MS can impair MRI assessment of the breast.

TRIAL REGISTRATION NUMBER

NCT04373655 (date of registration May 4, 2020).

Ideal marker for targeted axillary dissection (IMTAD): a prospective multicentre trial

BACKGROUND

Targeted axillary dissection (TAD) is an established method for axillary staging in patients with breast cancer after neoadjuvant chemotherapy (NAC). TAD consists of sentinel lymph node biopsy and initially pathological lymph node excision, which must be marked by a reliable marker before NAC.

METHODS

The IMTAD study is a prospective multicentre trial comparing three localisation markers for lymph node localisation (clip + iodine seed, magnetic seed, carbon suspension) facilitating subsequent surgical excision in the form of TAD. The primary outcome was to prospectively compare the reliability, accuracy, and safety according to complication rate during marker implantation and detection and marker dislodgement.

RESULTS

One hundred eighty-nine patients were included in the study-in 135 patients clip + iodine seed was used, in 30 patients magnetic seed and in 24 patients carbon suspension. The complication rate during the marker implantation and detection were not statistically significant between individual markers (p = 0.263; p = 0.117). Marker dislodgement was reported in 4 patients with clip + iodine seed localisation (3.0%), dislodgement did not occur in other localisation methods (p = 0.999). The false-negativity of sentinel lymph node (SLN) was observed in 8 patients, the false-negativity of targeted lymph nodes (TLN) wasn´t observed at all, the false-negativity rate (FNR) from the subcohort of ypN + patients for SLN is 9.6% and for TLN 0.0%.

CONCLUSION

The IMTAD study indicated, that clip + iodine seed, magnetic seed and carbon suspension are statistically comparable in terms of complications during marker implantation and detection and marker dislodgement proving their safety, accuracy, and reliability in TAD. The study confirmed, that the FNR of the TLN was lower than the FNR of the SLN proving that the TLN is a better marker for axillary lymph node status after NAC.

TRIAL REGISTRATION

NCT04580251. Name of registry: Clinicaltrials.gov. Date of registration: 8.10.2020.

Targeted Axillary Dissection with 125I Seed Placement Before Neoadjuvant Chemotherapy in a Danish Multicenter Cohort

BACKGROUND

Targeted axillary dissection (TAD), with marking of the metastatic lymph node before neoadjuvant chemotherapy (NACT), is increasingly used for breast cancer axillary staging. In the case of axillary pathological complete response (ax-pCR), axillary lymph node clearance can be omitted. Several marking methods exist, most using re-marking before surgery. Feasibility, learning curve, and identification rate (IR) vary. Marking with 125I seed before NACT makes re-marking at surgery redundant, possibly increasing feasibility and IR. Here, TAD with 125I seed placed before NACT is evaluated in a Danish multicenter cohort.

METHODS

Patients staged with 125I TAD in Denmark between 1 January 2016 and 31 August 2021 were included. Patients were identified in radioactivity-emitting implant registries at the radiology departments and from the Danish Breast Cancer Group database. Data were extracted from patients' medical records. Information on patient/tumor characteristics, 125I seed activity, marking period, TAD success, number of sentinel nodes (SNs), the histopathological status of excised nodes, and whether the marked lymph node (MLN) was an SN were registered.

RESULTS

142 patients were included. The IR of the MLN was 99.3%, and the IR of the SLNB was 91.5%. TAD success was 91.5%. Minor challenges in marking or removal of the MLN were noted in three patients. In 72.3% of the patients, the MLN was a sentinel node. Overall, 40.8% had axillary pCR.

CONCLUSION

TAD with 125I seed marking before NACT is feasible without re-marking at surgery and with only minor surgical challenges. The IR is high. Staging with TAD spares 41% of breast cancer patients an axillary dissection.

Pre-operative localisation of axillary lymph nodes using radiofrequency identification (RFID) tags: a feasibility assessment in 75 cases

AIM

To evaluate the safety and feasibility of using radiofrequency identification (RFID) tags for the localisation of axillary nodes prior to targeted excision in a National Health Service (NHS) breast unit.

MATERIALS AND METHODS

Retrospective data collection was carried out to analyse the first 75 cases of RFID-targeted axillary nodes inserted between 12 June 2019 and 27 October 2022, during which an overall total of 1,296 breast and axillary tags were deployed in 1,120 patients.

RESULTS

Of the 75 axillary tags, 70 (93%) had a primary breast cancer and five (7%) had no known breast cancer but had an abnormal node targeted for diagnostic excision. Of the 70 with breast cancer, 20 (29%) underwent neoadjuvant chemotherapy (NAC) including one neoadjuvant endocrine therapy. Localisations were performed an average of 11 days before surgery (median 6, range 1-95; n=75). Patients undergoing NAC had their tags inserted after completing treatment due to the artefact caused by the tags on magnetic resonance imaging (MRI). Tag deployment had a 100% success rate, with 62 tags (83%) lying within the node and 13 tags (17%) lying directly adjacent to the node, either in direct contact (nine of 13), or a maximum of 8 mm from the target (four of 13). All tags and their respective nodes were excised successfully at surgery with no significant complications. There were four cases of tag dislodgement during excision, but overall, this did not compromise retrieval of the tag or the node.

CONCLUSIONS

The use of RFID tags for the preoperative localisation of axillary nodes is safe and feasible.