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

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%.

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).

Clinical utility of axillary nodal markers in breast cancer

BACKGROUND

De-escalation of axillary surgery for lymph node (LN) positive breast cancer is facilitated by marking involved nodes which, when removed with sentinel nodes constitute risk-adapted targeted axillary dissection (TAD). Whether after chemotherapy or for primary surgery, selected patients with biopsy-proven involvement of nodes may be eligible for axillary conservation. Likewise, impalpable recurrence or stage 4 patients with localised axillary disease may benefit. In these contexts, several devices are used to mark biopsied nodes to facilitate their accurate surgical removal. We report our experience using the paramagnetic MAGSEED (Endomag®, Cambridge, UK).

METHODS

Local approval (BR2021_149) was obtained to interrogate a prospective database of all axillary markers. The primary endpoint was successful removal of the marked LN.

RESULTS

Of 241 markers (in 221 patients) inserted between October 2018 and July 2022, all were retrieved. Of 74 patients who had Magseeds® inserted after completion of NACT (involved nodes initially marked using an UltraCor™Twirl™ marker), the Magseeds® were found outside the node in neighbouring axillary tissue in 18 (24.3%) patients. When Magseeds® were placed at commencement of NACT in 54 patients, in only 1 (1.8%) was the marker found outside the node - a statistically significantly lower rate (Chi² 10.7581 p = 0.001038). For 'primary TAD' patients and those localised for recurrent or stage IV disease, all 93 had the Magseed® found within the biopsied node.

CONCLUSION

This series supports our axillary nodal marking technique as safe and reliable. For TAD following NACT, placement at the start of treatment led to a significantly higher localisation rate.

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.