As awareness of the importance of early detection for breast cancer increases, more Americans are having regular mammograms; as a result, increasing numbers of breast tumors are identified early. Many of these tumors are sufficiently small that they cannot be felt but they must still be remove. We are building and deploying simple, practical devices to help surgeons to locate and remove these tumors.

Typically, a surgeon is guided to a small breast tumor by following a wire placed earlier that day by a radiologist. We have designed an "optical wire" that is made by gluing an optical fiber to one of the standard wires usually used to find tumors. When the optical wire is connected to a light source, the tip of the fiber glows. We have just completed a very promising (first-ever) feasibility study of the optical wire in eight patients. This prototype device has facilitated tumor removal in all eight patients. The optical wire has the potential to replace the standard Kopans wire used in roughly 30% of breast conserving surgeries. This translates to roughly 100,000 lumpectomies each year in the U.S. The optical wire has the potential to (1) reduce the number of resections having positive margins, (2) reduce morbidity by allowing the surgeon to use a more anatomically appropriate approach, (3) reduce operative times, (4) reduce scarring, and (5) produce spherical resections that are ideal for partial breast irradiation modalities.

We believe that light can provide simple, practical benefits to the current practice of breast conserving surgery. We have on-going work to test the optical wire in more patients and to engineer new devices that will further aid the surgeon in removing small, non-palpable tumors.


A. Dayton, "Light-Guided Lumpectomy: Visual and Frequency Domain Localization of Breast Lesions", Oregon Health & Science University, (2013).


A. Dayton, L. Soot, R. Wolf, C. Gougoutas-Fox, S. A. Prahl, "Light Guided Lumpectomy: First Clinical Experience," J. Biophotonics, 4, 752-758 (2011).


A. Dayton, N. Choudhury, S. A. Prahl, "Light Guided Lumpectomy: Is Continuous Wave or Frequency Domain More Accurate," SPIE Proceedings on Biomedical Applications of Light Scattering IV, 7573, (2010).

A. Dayton, L. Soot, R. Wolf, C. Gougoutas-Fox, S. A. Prahl, "Light Guided Lumpectomy: Device," J. Biomed. Opt., 15, 061706 (2010).


A. L. Dayton, S. A. Prahl, "Optical Wire Guided Lumpectomy," SPIE Proceedings on Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications IX, 7173, 71730M-1-71730M-8 (2009).

S. Prahl, A. Dayton, "Optical Wire Illuminator," United States Provisional Patent Application, (2009).