MRI, optical scanning during surgery accurately locate small breast cancer tumors

“We have developed a technique that gives the surgeon, at the time of surgery, a 3-D picture of where the cancer is in the breast using MRI,” said Richard J. Barth Jr., MD, section chief, General Surgery, associate professor of Surgery, Geisel School of Medicine, Dartmouth and member of the Norris Cotton Cancer Center. “This is the first time that optical scanning and MRI have been combined to localize breast cancer.”

Currently, a wire is inserted into the breast before surgery to mark these small tumors. This technique requires a separate procedure, which can be uncomfortable for the patient and is not very accurate—cancer cells are left behind about 30 to 40 percent of the time, and additional surgery is needed to remove remaining cancer.

Barth says that this new method of locating breast tumors uses a pre-operative MRI as a map of the tumor and an optical scan to identify the tumor’s size, shape, and location. Combined the two create an interactive 3-D image on a computer screen. Conceptually it is similar to a car’s GPS. The uploaded maps would be the MRI, and the optical scan provides the “your are here” arrow for the surgeon. This more accurate picture of the tumor location and its edges allows for a more precise surgical excision.

Barth will soon be initiating a randomized prospective study of patients with non-palpable breast cancer to test whether the new method of localization with optical scanning and supine MRI results in a lower rate of positive margins than the old wire localization method.