Magnetic marker localisation in breast cancer surgery.

State of the art paper Oncology Magnetic marker localisation in breast cancer surgery Jan Žatecký, Otakar Kubala, Petr Jelínek, Milan Lerch, Peter Ihnát, Matúš Peteja, Radim Brát Department of Surgical Studies, Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic Submitted: 26 April 2019; Accepted: 12 July 2019 Online publication: 14 March 2020 Arch Med Sci 2023; 19 (1): 122–127 DOI: https://doi.org/10.5114/aoms.2020.93673 Copyright © 2020 Termedia & Banach Corresponding author: Jan Žatecký 233 Slezská St Neplachovice, 747 74 Czech Republic E-mail: Abstract Since mammographic screening programmes were initiated, the spectrum of breast cancer has changed in terms of impalpable tumours, thus causing the development of new localisation methods, including magnetic markers. We offer herein an up-to-date review focused on two magnetic markers (Magseed, MaMaLoc) currently used in breast cancer surgery for the localisation of breast tumours or pathological axillary nodes. Magnetic marker localisation presents a safe and reliable method for breast tumour marking. Four currently available prospective studies demonstrate that the Magseed system has a negative margin rate and a successful localisation rate, both of which are comparable to standard marking systems used in breast cancer surgery. The main benefits of magnetic markers are that they require no radiation safety measures, and they offer the possibility of longer deployment times, thus simplifying surgery scheduling. The most important drawbacks are cost of the system, depth limitation and need for frequent probe recalibration. Key words: breast cancer surgery, magnetic marker, impalpable breast tumour, Magseed, MaMaLoc. Introduction Breast cancer is the most common worldwide malignancy in women, and its incidence is increasing due to the success of mammography screening programmes, which enable the detection of small and often non-palpable tumours [1]. At present, 25–35% of diagnosed breast cancer tumours are non-palpable [2]. As a result, techniques using markers for precise localisation of the tumour have been developed, with markers being introduced by a radiologist into the centre or to the periphery of the tumour, thus simplifying its detection during surgery. Targeted axillary dissection (TAD) presents another important option in breast cancer surgery, where the employment of reliable markers is of paramount importance. Targeted axillary dissection consists of a sentinel lymph node biopsy (SLNB) and the excision of the pathological lymph node, which has been marked before neoadjuvant therapy. If metastasis is found in the sentinel lymph node or in a marked pathological node, axillary dissection (AD) levels I and II are performed. Targeted axillary dissection seems to be more accurate (by virtue of the false-negativity rate) than SLNB only, especially in women after neoadjuvant therapy with initially node-positive axillary status [3], although it is dependent on the reliability of the used marker. Creative Commons licenses: This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY -NC -SA 4.0). License (http://creativecommons.org/licenses/by-nc-sa/4.0/). Magnetic marker localisation in breast cancer surgery Table I. Summary of magnetic localisation methods Method Size Number of prospective cohorts Magnetic resonance imaging compatibility Detectable up to Commercially available Megseed 1 × 5 mm 4 Yes (bloom effect up to 4–6 cm) 30 mm Yes MaMaLoc 1.5 × 3.5 mm 1 No 35 mm No Apart from standard markers in breast cancer surgery (such as wire localisation or metal clips), magnetic markers present a promising new option for breast tumour localisation. A lite rature search revealed that published data on the topic are highly insufficient, and so the aim of the present paper is to offer an up-to-date review focused on magnetic marker localisation in breast cancer surgery. Non-magnetic markers Many techniques are used nowadays for localising non-palpable breast tumours. Wire-guided localisation (WGL) is a widely used method, and it was first reported in 1965 [4]. The most commonly published disadvantages of WGL are patient discomfort, wire migration or transection, limitations to surgical incisions because of wire placement, vaso-vagal episodes and complications regarding surgery scheduling (WGL must be performed on the same day as surgery) [4–7]. Implanted tissue marker clips are markers without a specific detection system, and therefore preoperative localisation by WGL or a specimen radiograph (after excision of the lesion for confirmation that the clip is included) is necessary. Clip migration and problematic clip localisation present the main difficulties of the technique [8]. Carbon marking is a cheap marking technique that creates a tattoo in place of an injection, but it can imitate malignancy as a result of foreign-body giant-cell reaction [7, 9, 10]. Radioactive seed localisation (RSL) using iodine-125 (125I) seeds was first described in 1999 by Dauway et al. [11]. Since then, authors of several studies have demonstrated the non-inferiority of RSL compared to WGL [12–14]. The main advantage of RSL is that the seed can be put in place many days or even weeks before surgery, which allows for much easier surgery scheduling. The main RSL disadvantage rests in radiation safety regulations. In the last few years, several new and non-radioactive non-wire localisation methods have appeared. SAVI SCOUT uses infrared light and radar technology, whereby the marker (12 × 4 mm with two 4 mm-long antennas) is detected by a handpiece and console system [5, 6]. Available data suggest that SAVI SCOUT is comparable to WGL in terms of both the negative margin and the re- Figure 1. Magseed – 1 × 5 mm stainless steel magnetic localisation seed (with permission of Sysmex CZ Ltd) Figure 2. Sterile introducer and Magseed (with permission of Sysmex CZ Ltd) excision rates. However, its main limitations are cost, nickel content relating to the risk of allergy reaction, device failure by interaction with electrocautery and high directionality of the system [5, 6]. Radiofrequency identification tags (RFIDs) are based on radio wave transmission and contain a microprocessor in which information can be stored [7]. It has a history of usage as an identification device, e.g. for pets, but the first clinical data about intraoperative use are very promising, with one advantage over other localisation technologies – the probe can detect distance from the tag [15, 16]. Magnetic markers At present, there are two markers that use magnetic susceptibility to localise tumours in breast cancer surgery – Magseed and MaMaLoc (Table I). Magseed (Endomagnetics, Inc.) was approved by the FDA for breast lesion localisation in 2016 [6]. The method utilises 1 × 5 mm stainless steel magnetic seeds (Figure 1) implanted by an 18 G steril (...truncated)