番茄社区

KISSIMMEE, Fla. – Use of radiofrequency identification (RFID) to tag breast cancers for surgical excision had similar success as the standard of using wires to mark lesion locations prior to surgery, researchers reported here from a small retrospective study.

"We found no statistically significant differences in percentage of cases with positive margins, in close margins, and in the need for re-excision in comparing the two modes of marking the breast cancers," said Stephanie Riviere, MD, a resident in pathology at Rhode Island Hospital/Warren Albert Medical School of Brown University in Providence, Rhode Island.

But RFID tags may still be preferred for other reasons, she told 番茄社区 at the College of American Pathologists' annual meeting, where she presented the study.

"We do know that patients prefer using the RFID tag so they do not have to spend time before surgery with these wires sticking out of their breasts," she told 番茄社区.

"RFID for tag localization for breast cancer excision is a relatively new procedure," she explained. "There are studies that suggest it is superior to wire-guided localization due to easier surgical technique and better patient experience. In addition, RFID tags have no radiation governance requirement as seen with radioactive seeds used for this purpose."

Margaret Moore, MD, a pathology resident at the University of Virginia, Charlottesville, told 番茄社区 that "since these outcome measures are similar, and the patients experience is better with RFID, I think that doing it with the new procedure is reasonable."

At her institution, the choice is between wires and radioactive seeds. "The advantage of the RFID system over seeds is that we would not have the environmental safety issues with the RFID tags," said Moore, who was not involved with the study.

She described the standard procedure for patients slated for breast surgery to remove a non-palpable mass. "The radiologist usually inserts a wire into the breast so the surgeon knows where to go to take the mass out," she said. "This can be uncomfortable for the woman. So the new procedure is to insert this RFID tag at the site of the tumor at the time of the biopsy." These tags are a fraction of a centimeter in length; surgeons then locate the tag, and thus the mass to be removed, with a handheld probe.

She and colleagues performed a retrospective analysis of 122 consecutive women who underwent the procedures from March to September 2018, including 66 getting RFID tags and 56 receiving standard wire locators.

They found:

• Positive margins in 10.6% of the RFID patients and in 5.3% of the wire-guided patients (P=0.2)
• Close margins, defined as less than 2 mm, occurred among 33.3% of the RFID patients and in 28.6% of the wire-guided patients (P=0.7)
• Close margins, defined as less than 1 mm, were observed in 24.2% of the RFID patients and in 19.6% of the wire-guided procedures (P=0.5)
• Re-excision was performed in 18.2% of the RFID patients and in 8.9% of the wire-guided patients (P=0.1)

"The results we see here are based on relatively small numbers of patients, so our results should be confirmed in studies with larger numbers of patients," Riviere said.

She also noted that patients in the study were not randomized, and were selected for wire-guided or RFID placement at surgeons' discretion. "While patients seem to like the RFID tag better, they really don't get to choose which system they will receive as it is based on what is prevalent at the hospital or with the radiologist. I would be comfortable if my patients were selected to receive either system."

Riviere did note that more re-excisions were performed with RFID tagging even though the difference was not statistically significant. Before concluding that such differences are meaningful, she said, her group intends to keep tracking outcomes with RFID tags. Moore also commented that "I would like to see more numbers of patients to see if those excess re-excision rates hold up."