Radio-frequency identification (RFID) tags, which employ electromagnetic fields, have a history stretching back to World War II. Passive tags contain electronically stored information and communicate using energy collected from the interrogating radio waves transmitted by the RFID reader. In contrast to the ubiquitous barcode – which must be within the reader’s line of sight – RFIDs can be embedded in the object being tracked. Although there are well-founded concerns regarding privacy, the Food and Drug Administration in the USA has approved the use of implanted RFID tags in humans. Faxitron, a company that specializes in point-of-care specimen radiography, has just announced the LOCalizer for identifying breast lesions.
With the success of breast screening programmes, lesions are now typically smaller, less defined and harder to locate. In fact, 50% of all breast tumours cannot be palpated at diagnosis, and this complicates the job of the surgeon who cannot rely on touch alone to locate the lesion. For many years surgeons have used wires with barbed ends to guide the surgical removal of the lesion but there are well-documented problems with this approach. Radio-active seeds have also been used but here too there are complications and challenges.
Faxitron’s breast lesion localization system consists of: miniature RFID tags that can be implanted in the lesion up to 30 days prior to surgery; an applicator for implanting the tags; a sterile probe; and a handheld reader (seen at left). Since the tags are clearly visible with X-rays, ultrasound and magnetic resonance imaging, they can be accurately placed within the lesion by the radiologist using the applicator. Once the tags have been implanted, the probe may be applied directly on the skin to determine the location and distance to the lesion, thereby enhancing surgical planning.
Each tag has a unique identification number and is sealed in a special sheath that prevents it from moving. Donogh O’Driscoll of Faxitron stated: “As the breast imaging industry gets better at detecting smaller breast lesions, we must establish a new gold standard for lesion localization. LOCalizer could be the breakthrough product needed to make lumpectomies and breast biopsies safer, more efficient, and a better experience for both surgeons and patients.”
Christine Dauphine, a breast surgeon from Los Angeles, appreciates being able to accurately measure the distance to the target lesion, and commented: “We were thrilled at the prospect of providing patients with a localization method that, by design, will avoid the anxiety of having additional procedures on the day of surgery.”