Patient-Specific 3D-Printed Guide Improves Precision in Breast-Conserving Surgery

Achieving clear margins during breast-conserving surgery remains challenging, especially when poorly defined tumor edges lead to repeat operations. Positive margins occur in about 20% of cases and in 30–40% of ductal carcinoma in situ or invasive lobular cancer cases, while irregular tumor shapes further complicate excision. These challenges highlight the need for intraoperative tools that display patient-specific tumor geometry in the operative position. A new system now provides this guidance and has been shown in a pivotal randomized trial to reduce positive margins and re-excisions.

Cairn Surgical’s (Lebanon, NH, USA) Breast Cancer Locator (BCL) System is designed to enable precise tumor localization and excision during lumpectomy. The system is built from a supine magnetic resonance imaging study obtained at the treating hospital and used to produce a patient-specific, three-dimensional–printed guide that conforms to the breast in the surgical position. Once positioned on the breast under anesthesia, surgeons place multiple bracketing wires through dedicated ports that outline the tumor’s size, shape, and location, including a clear margin, to guide resection.

In an international, prospective, multicenter, randomized controlled trial, 418 patients with non‑palpable invasive breast cancer or ductal carcinoma in situ were enrolled at 23 centers across the U.S., Canada, the U.K., and Austria. The study compared the BCL System with conventional wire localization and met its primary endpoint.

Across all patients, the pivotal trial demonstrated a 32% reduction in the positive margin rate—when tumor tissue is left behind—and a 34% reduction in re-excisions versus conventional wire localization, with a comparable safety profile. Results were presented at the American Society of Breast Surgeons annual meeting in Seattle. Clinical investigators will discuss the pivotal trial findings in a sponsored symposium at the meeting.

“The BCL System provided patient-specific information regarding the unique size, shape and location of each tumor, derived from supine MRI. Having detailed information about each tumor gave us information we could consider before and during each breast cancer surgery,” said Jennifer Gass, MD, Chief of Surgery, Women & Infants Hospital, Professor of Surgery, Obstetrics and Gynecology, The Warren Alpert Medical School of Brown University, and Principal Investigator of the BCL Trial.

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