Wire- and radiofrequency identification tag-guided localization of impalpable breast lesions: IBRA-NET localization study

The number of impalpable breast lesions requiring preoperative localization before surgery has increased in recent decades, with the expansion of breast screening services worldwide1. Wire-guided localization has historically been the most common method used2, with most breast surgeons and breast radiologists having extensive experience using this technique. Wire-guided localization, however, has several disadvantages, including wire migration and difficulties in wire tip localization during surgery, which may result in the excision of excess normal breast tissue. This technique is also associated with logistical challenges, as wires need to be inserted on the day of surgery. Despite these disadvantages of wire-guided localization, it remains inexpensive and effective.

Various alternative methods to wire localization have been developed, but many have notable drawbacks. Techniques such as radio-occult lesion localization (‘ROLL’)3 and radioactive seed localization4,5 are limited by radioactivity regulations, whereas other techniques, such as carbon-track marking6 and intraoperative ultrasonography7, are limited by difficulties with intraoperative lesion detection and the need for specialist ultrasonography training. More recently, a number of novel localization devices have entered the market, including radar-based Savi Scout8 (Cianna Medical Inc., Aliso Viejo, CA, USA), LOCalizer™ radiofrequency identification (RFID) tags9 (Hologic, Santa Carla CA, USA), magnetic technology-based Magseed®10 (Endomagnetics Inc., Cambridge, UK), and Pintuition (Sirius Medical, Eindhoven, Netherlands)11. These are all small, implantable non-radioactive devices that can be inserted into the breast or axilla weeks or months before surgery, all having the advantage of circumventing the logistical problems associated with guide wires. The principal difference between all these devices is in their mode of detection and, with no comparative evidence, product selection largely depends on user preference.

The LOCalizer™ system was the first RFID system commercially available in the UK and uses a 10.6 × 2 mm passive radiofrequency tag, each with its own unique five-digit ID number. Tags are inserted via preloaded 12G needles, with two different needle lengths available for use with both ultrasonographic and stereotactic insertion. Emerging data from users demonstrate that the device can accurately localize lesions, including screen-detected breast lesions and axillary lymph nodes, with similar re-excision rates to other localization techniques, such as wire-guided localization9,12. These data sets, however, are from case series, including relatively small numbers of patients, only one of which included a control group. As such, there remains the need for high-quality research to establish the safety and effectiveness of RFID in breast lesion localization to determine key outcomes and compare it with the standard of wire-guided localization.

It is likely that even more devices will enter the market in the coming years and both surgeons and patients will require data on their efficacy and safety13. Although RCTs are ideal, these are challenging in the context of breast lesion localization. The technique needs to be stable and standardized, and needs to have been adopted by sufficient numbers of surgeons. Efficacy data are also required, so that studies can be adequately powered. The iBRA-NET (implant BReast Reconstruction evaluation-NETwork) localization study is a well-powered multicentre observational platform study designed to meet these needs, providing an alternative approach to traditional randomized trials. It uses the IDEAL (idea, development, exploration, assessment, long-term study)14 2a/2b (development/exploration) framework to enable comparison of new localization devices with the standard of wire localization.

The iBRA-NET localization study has already reported on a national survey of practice and the outcomes of magnetic seed localization2,15,16. The outcomes from the third arm of the platform study, comparing wire- and RFID tag-guided localization, are reported here.