The primary goal of this research study is to see if we can use photoacoustic imaging in breast cancer patients to identify sentinel lymph nodes, which are the first group of lymph nodes reached by cancer if it is
metastasizing (spread of the cancer cells to other parts of the body). Lymph nodes are small rounded or bean-shaped masses of lymphatic tissue and are an important part of your immune system. Lymph nodes are located throughout the body; they filter lymphatic fluid and remove foreign (not of the body) objects from the body and store special cells that can trap cancer cells or bacteria that are traveling through the body
in the lymph fluid. Photoacoustic imaging is a noninvasive way of taking pictures of structures inside your body. “Noninvasive” means that the imaging technique used does not require the injection of dyes,
although as part of this study, you will receive an injection of blue dye (described in Section 2 below) in order for us to determine if the photoacoustic imaging is useful. This is important because, if we determine that the photoacoustic imaging can identify sentinel lymph nodes, it could allow doctors to develop
noninvasive methods of staging patients with breast cancer.