Breast cancer is the most common cause of cancer death among women.Improving survival rates will require earlier detection, as well as more patient-and-cancer-type-specific therapy.Currently, innovative molecular imaging methods are being developed that could meet both requirements.One of the approaches is to combine newly developed contrast agents that target tissue alterations specific for breast cancer with optical imaging techniques.This presentation focuses on an optical method that can be used to visualize the presence of a fluorescent agent in the breast using a scanner based on optical fluorescence tomography during clinical studies.The scanner is patient friendly, fast, and makes use of visible and near-infrared light to generate 3D information on both the intrinsic optical transmission as well as the distribution of a fluorescing contrast agent in the breast.Here, the technology will be discussed, and proof-of principle results obtained with a non-targeted agent will be presented.