Study Reveals Method for Obtaining Highly Accurate Breast Tumor Imaging

Trial data show Cairn Surgical Inc.’s approach to breast imaging is more accurate and efficient than standard methods for detecting breast tumors.

Prone MRI—with the patient face down—is sensitive in assessing the extent of breast cancer and potentially identifying additional cancers missed by other methods, but has not definitively helped decrease the positive margin rate for breast cancer surgery. Supine MRI—with the patient face up in the surgical position—is a potential strategy to enhance breast cancer surgical precision but is not commonly used.

Cairn Surgical, however, developed a combined, single-session approach (prone and supine MRI) to seamlessly capture more precise and comprehensive tumor data while keeping the patient and tumor in the same supine position used in surgery. Supine imaging, integrated with conventional prone imaging, forms the foundation of the company’s Breast Cancer Locator (BCL) System, which helps surgeons achieve clear margins. It accomplishes this task by providing enhanced detail on tumor shape, size, and location that is not commercially available with current localization technologies.

“The study found that images resulting from the combined approach displayed clear tumor to fibroglandular contrast, similar to that resulting from separate imaging sessions, allowing for excellent visualization of tumor margins,” said Roberta M. diFlorio-Alexander, M.D., lead study author and associate professor of radiology at Geisel School of Medicine at Dartmouth. “Prone and supine MRI performed in one imaging session allows for accurate assessment of disease extent, which can provide important navigational guidance for innovative technology that optimizes the surgical approach.”

In the prospective study of 74 breast cancer patients—published online in the Journal of Breast Imaging—tumor-to-fibroglandular tissue contrast ratios (TFRs) from a single-session prone-to-supine breast MRI were compared to those from separate-day prone and supine breast MRIs. One standard bolus dose of contrast was delivered before each MRI in the session, consistent with standard cardiovascular MRI practice, and showed no adverse events. TFR values extracted from images segmented by an experienced radiologist and confirmed by an independent breast radiologist were compared to confirm the ability to precisely identify tumor margins and determine the feasibility of scaling the single-session technique for wider clinical use.

“The detailed 3D imagery we get from combining supine imaging with standard prone MRI is central to our approach of providing breast surgeons with the best possible surgical guidance, enabling their unprecedented success in achieving clear margins. By lowering the positive margin rate, our goal is to reduce re-excision surgeries and unnecessary delays in therapy,” Cairn Surgical Chief Technology Officer Venkat Krishnaswamy, Ph.D, stated. “Our single-session MRI approach is simple enough for almost any center to integrate into their workflow for the benefit of their patients and their outcomes.”

The BCL System comprises two components derived from the patient’s supine MRI. A customized 3D-printed form—the BCL—is produced that fits the unique shape of the patient’s breast and marks the tumor’s boundaries. An interactive, 3D breast tumor image is also produced—the Visualizer—that can be manipulated in real-time before and during surgery. The two technologies are used concurrently by a surgeon to guide precise tumor removal while minimizing the total tissue volume resected to attain clear margins and maintain breast cosmesis.

A paper published in the Annals of Surgical Oncology¹ reported that surgeons using the BCL System removed the entire tumor with clear margins in 94% of breast-conserving surgeries, corresponding to a 6% positive margin rate, without additional margin shaves or re-excisions. This performance is a 70% improvement on the widely recognized historical 20% positive margin rate for wire localization, the most commonly used method for surgical guidance today.

Cairn Surgical Inc. is developing patient-specific guides using patient imaging data and state-of-the-art 3D printing technologies that are commercially available in Europe and being studied in a U.S. pivotal trial. Cairn Surgical’s Breast Cancer Locator (BCL) System is designed to enable precise tumor localization and excision. The Breast Cancer Locator is considered an investigational device in the United States and is limited by U.S. law to investigational use only.

References
¹ Thill, M., Ghilli, M., Roncella, M. et al. A Multi-institutional Study to Evaluate the Effectiveness and Safety of a Supine MRI-Based Guidance System, the Breast Cancer LocatorTM, for Breast Conserving Surgery in Patients with Nonpalpable Breast Cancer. Ann Surg Oncol (2025). https://doi.org/10.1245/s10434-025-17513-4