Developments toward diagnostic breast cancer imaging using near-infrared optical measurements and fluorescent contrast agents

The use of near-infrared (NIR) light to interrogate deep tissues has enormo us potential for molecular-based imaging when coupled with NIR excitable dy es, More than a decade has now passed since the initial proposals for NIR o ptical tomography for breast cancer screening using time-dependent measurem ents of light propagation in the breast. Much accomplishment in the develop ment of optical mammography has been demonstrated, most recently in the app lication of time-domain, frequency-domain, and continuous-wave measurements that depend on endogenous contrast owing to angiogenesis and increased hem oglobin absorbance for contrast. Although exciting and promising, the neces sity of angiogenesis-mediated absorption contrast for diagnostic optical ma mmography minimizes the potential for using NIR techniques to assess sentin el lymph node staging, metastatic spread, and multifocality of breast disea se, among other applications. In this review, we summarize the progress mad e in the development of optical mammography, and focus on the emerging work underway in the use of diagnostic contrast agents for the molecular-based, diagnostic imaging of breast.