JCM | Free Full-Text | Early Breast Cancer: Could Combined LOCalizerTM and Ultrasound Localization Replace the Metallic Wire? A Multicentric Study

In the past, breast localization was necessary for excisional biopsies and conservative surgery. WGL has been the preferred method for many breast units worldwide over the last thirty years. It involves inserting a metallic wire into the breast tissue to indicate the occult lesion, typically performed under mammographic or ultrasound guidance. It can also be performed under magnetic resonance imaging, but this approach is reserved for selected cases due to the associated high costs [8,9,10,11,12,13,14,15]. However, WGL has several limitations, including migration issues (up to 3% of patients), patient discomfort, and the risks of wire fracture during the transfer from the radiology department to the operating room. To minimize these issues, wire placement is often performed on the same day as surgery, leading to logistical challenges and various adverse events such as pneumothorax, bleeding, and infections [16]. One significant limitation of WGL is that the incisional cut and the point of wire placement on the skin are often different, requiring the surgeon to modify the incision. Despite efforts to optimize this technique [17], patient stress remains a challenge. Clear margins obtained with WGL are reported to be 70.8% to 87.4% [18]. While WGL remains the standard method for breast localization, new wireless technologies have been proposed. Recently, the FDA approved a new device, LOCalizer^TM, aiming to improve the identification of non-palpable breast lesions. It involves the positioning of a Tag recognized by a dedicated surgical probe called the Pencil. While the preliminary results compared to conventional WGL were positive, limited data on its use have been reported. In a 2019 study by McGugin et al., LOCalizer^TM identification was compared to that of WGL in 503 procedures. All intended targets were successfully removed, and the specimen volumes were similar (p = 0.560 and 0.494), as were the operative times (p = 0.152 and 0.158). Re-excision rates were comparable by the surgical procedure (p = 0.615), surgical indication (DCIS p = 0.145; invasive carcinoma p = 0.759), and confirmed by multivariable analysis (OR 0.754, 95% CI 0.392–1.450; p = 0.397) [19]. Several studies have assessed the feasibility of the LOCalizer^TM system, focusing on various aspects such as the distance from the Tag in mm on the console; the unique code for each Tag, which is particularly useful for multiple localizations; and its potential use for axillary tailored dissections (TAD) [20]. In a previous study, a combined technique with US and the LOCalizer^TM system was utilized, showing encouraging results. The choice of combining both techniques (US and LOCalizer^TM system) arises from the ability to dynamically assess the distance from the margin of the lesion during the surgical procedure, rather than relying on the Repere, which could be placed in an eccentric position or even outside the measurement. Monitoring distances from the margins could also be achieved with mammography; however, this technique does not allow for real-time assessment during excision.

To the best of our knowledge, the current study is the first to compare the surgical and oncological outcomes of the combined LOCalizer^TM and US localization versus WGL alone for non-palpable BC. The primary endpoint was to evaluate oncologic radicality, and the combined method appeared to be safer and more accurate than WGL (100% vs. 93.4% cancer free margins, respectively). The results of the combined technique are even more encouraging than outcomes reported in literature regarding the exclusive use of the radiofrequency system. Perhaps the use of US and the evaluation of distances from the margins can improve surgeons’ orientation. Law et al. reported a re-operation rate of 6% in their study, assessing the adequacy of invasive and in situ breast carcinoma margins in radioactive seed- and wire-guided localization lumpectomies [21]. Regarding the radiofrequency system, different rates of R0 surgery have been described. Christenhusz et al. found clear resection margins in 92.7% of the cases (89 out of 96 patients), while Lamb et al. reported that 15.1% of surgeries had positive or close surgical margins requiring re-excision [22,23]. In 2021, a French group published a study protocol aiming to demonstrate the superiority of the RFID technique in terms of patient tolerance compared to the gold standard (hook wire). The study involved patients filling out a satisfaction questionnaire during two steps: during the placement of the device (RFID tag or hook wire) and during the postoperative consultation at one month. Radiologists and surgeons were also required to complete a questionnaire to evaluate the localization technique after the localization and surgery procedures, respectively [24]. In the current study, higher clinician and patient satisfaction was significantly reported for the combined approach for all the domains analyzed (p ³ vs. 20.6 ± 6.5 cm³, p = 0.003) and the lower specimen weight (19.2 ± 4.8 g vs. 24.0 ± 5.1 g, p = 0.002) in patients undergoing the combined approach, guaranteeing, as mentioned previously, a higher oncological radicality rate. Surgical excision of a non-palpable breast lesion requires a localization step. Among the available techniques, WGL is the most commonly used. Other techniques have been developed in the last two decades with the aim of improving outcomes and logistics. Intraoperative ultrasound is associated with significantly higher negative margin rates, and radioactive techniques are non-inferior to WGL.