Cairn Surgical, Inc., an innovative medical technology firm striving to make breast cancer surgery more precise, has announced that a study published online in the Journal of Breast Imaging has showed that a single imaging session combining prone and supine MRI performed prior to breast conserving surgery provides highly accurate and efficient imaging of breast tumours that could contribute to significantly reducing positive surgical margins.
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 the precision of breast cancer surgery but is not commonly used today.
Cairn Surgical developed the combined, single-session approach outlined in the paper to seamlessly capture more precise and comprehensive tumour data while keeping the patient and tumour in the same supine position used in surgery. Supine imaging integrated into conventional prone imaging serves as the foundation for the company’s Breast Cancer Locator (BCL) System, which is designed to help surgeons achieve clear margins. It does this by providing enhanced detail on tumour shape, size, and location that is not commercially available today with current localisation technologies.
“The study found that images resulting from the combined approach displayed clear tumour to fibroglandular contrast, similar to that resulting from separate imaging sessions, allowing for excellent visualisation of tumour margins,” said Roberta M. diFlorio-Alexander, MD, lead author of the paper 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 optimises the surgical approach.”
In the prospective study of 74 breast cancer patients, tumour-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 prior to 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 tumour 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 novel 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 reexcision surgeries and unnecessary delays in therapy,” said Venkat Krishnaswamy, Ph.D, Chief Technology Officer for Cairn Surgical. “Our single-session MRI approach is simple enough for almost any centre to integrate into their workflow for the benefit of their patients and their outcomes.”
The BCL System is comprised of two components created from the patient’s supine MRI. A customised 3D-printed form — the BCL — is produced that fits the unique shape of that patient’s breast and marks the tumour’s boundaries. An interactive, 3D image of the tumour in the breast 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 tumour removal while minimising the total tissue volume resected, with the goal to attain clear margins and maintain breast cosmesis.
A recently-published paper in the Annals of Surgical Oncology1 reported that surgeons using the BCL System removed the entire tumour with clear margins in 94 per cent of breast conserving surgeries, corresponding to a positive margin rate of six per cent, without additional margin shaves or reexcisions. This performance is a 70 per cent improvement on the widely-recognised historical positive margin rate of 20 per cent for wire localisation, the most commonly used method for surgical guidance today.
Pictured: Venkat Krishnaswamy, Ph.D, Chief Technology Officer for Cairn Surgical
References:
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
