Improving Accuracy in Breast Cancer Surgery
Mastectomy or lumpectomy? What will my breast look like after surgery? Will my surgeon get all of the cancer on the first attempt? These are just a few of the many questions patients with breast cancer face. A new technology developed at Dartmouth-Hitchcock's (D-H's) Norris Cotton Cancer Center (NCCC) holds promise for answering such questions with more certainty, less stress and a lower overall cost.
The Breast Cancer Locator gives surgeons the ability to remove tumors more accurately, reducing the need for second surgeries, and preserving the shape and appearance of the breast. The Breast Cancer Locator, which is a 3-D printed plastic form, was invented a year ago by D-H surgeon Richard Barth, MD, in collaboration with engineers from Dartmouth’s Thayer School of Engineering—Keith Paulsen, PhD, the Robert A. Pritzker Professor of Biomedical Engineering, and Venkataramanan Krishnaswamy, PhD, now chief technology officer at CairnSurgical, LLC. Barth is also a professor at the Geisel School of Medicine at Dartmouth and a recipient of the 2015 Dartmouth SYNERGY Clinician-Entrepreneur Fellowship. This, along with the generosity of donor Charlotte Metcalf, provided him with resources and dedicated time to develop and study the commercial potential of the Breast Cancer Locator.
“The Breast Cancer Locator lets a surgeon know exactly where the tumor is located,” says Paulsen. Mammograms, ultrasounds and MRIs are good at imaging tumors within the breast, but it has always been a challenge for surgeons to precisely locate and identify the margins of a tumor during surgery because of the way soft tissue can change shape.
Custom printed for each patient based on an MRI scan, the Breast Cancer Locator is designed to help surgeons more accurately remove non-palpable tumors—cancerous tissue that cannot be distinguished by touch. The current standard method, wire localization, results in a complete removal only 70 percent of the time. Currently, 30 percent of women who undergo a lumpectomy need a second surgery to remove cancerous tissue that was missed the first time.
Each Breast Cancer Locator is fabricated at the Dartmouth Regional Technology Center. The Breast Cancer Locator is placed on the patient’s breast at the start of an operation. Openings in the surface of the Breast Cancer Locator allow the surgeon to draw the tumor edges on the breast surface. The surgeon then injects blue dye through cylindrical ports on the Breast Cancer Locator surface to mark the edges of the cancer within the breast and places a wire in the center of the tumor. Part of the Breast Cancer Locator package is software that gives surgeons in the operating room a three-dimensional picture of the breast cancer, so they also know the precise distance of the cancer from the skin surface and the underlying chest wall.
To test the accuracy of the Breast Cancer Locator , Dartmouth investigators (including Barth, Krishnaswamy, Paulsen, radiologist Tim Rooney, MD, pathologist Wendy Wells, MD, and surgical oncologist Christina Angeles, MD) are first using the Breast Cancer Locator in patients whose cancers can be felt. In a clinical study of 18 patients at NCCC, the Breast Cancer Locator perfectly localized the cancer in 17 cases. The researchers modified their technique slightly after one sub-optimal localization, and all subsequent tumors have been perfectly localized. Barth recently presented the results of this study at the American Society of Breast Surgeon’s annual meeting in April 2017.
Low Cost, High Value
As a breast cancer survivor, Charlotte Metcalf knows firsthand what such an advance could mean for patients, and that’s why she made a generous gift in support of the Breast Cancer Locator clinical trials.
“The seed money I provided will further their chances of securing federal grants to establish the Breast Cancer Locator as a means to enable all women who have been diagnosed with breast cancer to avoid a second invasive procedure,” says Metcalf, who has supported breast cancer research at NCCC for the past 10 years.
The team has begun a broader clinical study involving patients at several New England hospitals, designed to demonstrate that the technology can be used at other facilities to accurately localize breast cancer. If all goes well, the team hopes to receive a federal Small Business Innovation Research grant and will work toward approval by the U.S. Food and Drug Administration (FDA).
“The next phase is to directly compare the effectiveness of the Breast Cancer Locator to wire localization” in a large multicenter randomized prospective trial, says Barth. “We hope to begin a year from now. We expect that the Breast Cancer Locator procedure will reduce the need for a second surgery, which is a significant burden on patients and health-care costs.” Conservative estimates suggest that the Breast Cancer Locator has the potential to save in excess of $300 million annually by avoiding repeat surgeries.
The Breast Cancer Locator is the research team’s second generation technology, as they attempt to more accurately localize breast cancer during breast-conserving surgery. In 2014, they began a clinical trial, funded by the National Institutes of Health, testing an image-guided technique that allowed NCCC surgeons to make precise tumor excisions using a three-dimensional MRI-derived image. The preliminary results are promising, demonstrating the benefits of being able to better visualize the cancer location in the operating room; however, the first-generation technique was more complicated, which would likely limit its general use. The group then created the relatively low-tech Breast Cancer Locator form, which can easily and quickly be used to localize breast tumors.
“We think eventually any surgeon in the country will be able to remove a patient’s breast cancer in a single surgery with the Breast Cancer Locator,” says Barth. That’s welcome news for tens of thousands of patients.