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

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.

The Effect of Wire Versus Magnetic Seed Localization on Lumpectomy Cavity Size

PURPOSE

Our purpose was to assess whether an association exists between surgical localization technique and lumpectomy cavity size on radiation therapy planning computed tomography (CT) scan.

METHODS AND MATERIALS

A single-institution retrospective review was conducted of women undergoing breast conserving surgery with wire or magnetic seed guided lumpectomy followed by adjuvant radiation therapy from 2018 to 2021. Patients of a surgeon only performing 1 localization technique or undergoing bracketed localization were excluded. The primary outcome was lumpectomy cavity size on simulation CT. Confounding due to imbalance in patient and tumor factors was addressed with overlap weights derived from a propensity score analysis and used in a weighted multivariable analysis. Secondary outcomes included positive margins, total pathologic volume, boost delivery, and boost modality.

RESULTS

Of 617 women who received lumpectomy during the study period, 387 were included in final analysis. Tumors of patients undergoing seed localization were more likely unifocal, assessable by ultrasound, and smaller. Seed use rates ranged from 27.7% to 70.7% per surgeon. There was no difference in positive margins (6.4 vs 5.4%, P = .79) or second surgeries (9.4 vs 8.1%, P = .79) between groups. Close margin rates were similar for ductal carcinoma in situ (P = .35) and invasive carcinoma (P = .97). In unadjusted bivariable analyses, wire localization was associated with larger total pathology volume (P = .004), but localization technique showed no association with CT cavity volume (P = .15). After adjusting for potentially confounding variables, multivariable analysis failed to show an association between localization technique and either CT cavity (P = .35) or total path volume (P = .08). There was no difference in indicated-boost delivery (P = .15) or electron boost (P = .14) by localization technique.

CONCLUSIONS

There was no significant difference in CT cavity size by localization technique, suggesting choice between surgical techniques does not impede radiation therapy boost delivery.

The Magnetic Technique-A Novel and Promising Method to Improve Axillary Staging Localisation from a Swedish Perspective

The magnetic technique using superparamagnetic nanoparticles of iron oxide has been well established for sentinel lymph node detection. Its main advantage is in the context of logistics, with the possibility to inject several weeks before surgery and the possibility to give access to sentinel lymph node biopsy for women worldwide in places without nuclear medicine facilities. We have not yet seen the full potential of this technique, and new implications have been developed for breast tumour localisation with paramagnetic clips and axillary staging after neoadjuvant chemotherapy using paramagnetic clips inserted in lymph node metastases before chemotherapy. In this report, we have presented our experience of the magnetic technique starting in 2014, and we have highlighted our current and future research directions.

Localization Techniques for Non-Palpable Breast Lesions: Current Status, Knowledge Gaps, and Rationale for the MELODY Study (EUBREAST-4/iBRA-NET, NCT 05559411)

BACKGROUND

Surgical excision of a non-palpable breast lesion requires a localization step. Among available techniques, wire-guided localization (WGL) is most commonly used. Other techniques (radioactive, magnetic, radar or radiofrequency-based, and intraoperative ultrasound) have been developed in the last two decades with the aim of improving outcomes and logistics.

METHODS

We performed a systematic review on localization techniques for non-palpable breast cancer.

RESULTS

For most techniques, oncological outcomes such as lesion identification and clear margin rate seem either comparable with or better than for WGL, but evidence is limited to small cohort studies for some of the devices. Intraoperative ultrasound is associated with significantly higher negative margin rates in meta-analyses of randomized clinical trials (RCTs). Radioactive techniques were studied in several RCTs and are non-inferior to WGL. Smaller studies show higher patient preference towards wire-free localization, but little is known about surgeons' and radiologists' attitudes towards these techniques.

CONCLUSIONS

Large studies with an additional focus on patient, surgeon, and radiologist preference are necessary. This review aims to present the rationale for the MELODY (NCT05559411) study and to enable standardization of outcome measures for future studies.