Investigation of optical coherence micro-elastography as a method to visualize cancers in human breast tissue

Accurate intraoperative identification of malignant tissue is a challenge in the surgical management of breast cancer. Imaging techniques that help address this challenge could contribute to more complete and accurate tumor excision, and thereby help reduce the current high re-excision rates without resorting to the removal of excess healthy tissue. Optical coherence micro-elastography (OCME) is a three-dimensional, high-resolution imaging technique that is sensitive to micro-scale variations of the mechanical properties of tissue. As tumor modifies the mechanical properties of breast tissue, OCME has the potential to identify, on the micro-scale, involved regions of fresh, unstained tissue. OCME is based on the use of optical coherence tomography (OCT) to measure tissue deformation in response to applied mechanical compression. In this feasibility study on 58 ex vivo samples from patients undergoing mastectomy or wide local excision, we demonstrate the performance of OCME as a means to visualize tissue microarchitecture in benign and malignant human breast tissues. Through comparison with corresponding histology and OCT images, OCME is shown to enable ready visualization of features such as ducts, lobules, micro-cysts, blood vessels and arterioles, and to identify invasive tumor through distinctive patterns in OCME images, often with enhanced contrast compared to OCT. These results lay the foundation for future intraoperative studies.