Near infrared fluorescent optical imaging for nodal staging

Nodal staging plays a critical role in the evaluation of disease progression and design of therapeutic strategies in the treatment of most cancer patients. For example, in breast cancer, intradermal (i.d.) or subcutaneous (s.c.) administration of a nonspecific ${}^{99\mathrm{m}}\mathrm{Tc}$ -radiocolloid is used to identify the tumor draining or sentinel lymph node for resection. Once the surgical pathologist confirms the presence of cancer cells in the resected sentinel lymph node, additional nodes around the axilla are removed to better assess the extent of lymph node involvement. The accuracy of nodal staging is critical for judicious selection of effective therapy. The inability to surgically resect inaccessible tumor-draining lymph nodes, such as the internal mammary or supraclavicular lymph nodes in breast cancer patients, or the pelvic lymph nodes that drain the prostate in prostate cancer patents, can compromise oncologists’ ability to accurately stage and select proper therapy. Noninvasive, diagnostic imaging of cancer-positive lymph nodes could positively impact the manner in which tumor-node-metastasis (TNM) staging is performed.