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Near infrared fluorescent optical imaging for nodal staging

2008; SPIE; Volume: 13; Issue: 4 Linguagem: Inglês

10.1117/1.2953498

1560-2281

Lakshmi Sampath, Wei Wang, Eva M. Sevick‐Muraca,

Monoclonal and Polyclonal Antibodies Research

Current techniques to assess lymph node metastases in cancer patients include lymphoscintigraphy after administration of a nonspecific radiocolloid in order to locate and resect lymph nodes for pathological examination of harbored cancer cells. Clinical trials involving intradermal or subcutaneous injection of antibody-based nuclear imaging agents have demonstrated the feasibility for target-specific, molecular imaging of cancer-positive lymph nodes. The basis for employing near-infrared (NIR) optical imaging for assessing disease is evidenced by recent work showing functional lymph imaging in mice, swine, and humans. We review antibody-based immunolymphoscintigraphy with an emphasis on the use of trastuzumab (or Herceptin) to target human epidermal growth factor receptor-2 (HER2) overexpressed in some breast cancers. Specifically, we review in vitro and preclinical imaging data from our laboratory that show how the dual-labeled agent (111In-DTPA)n-trastuzumab-(IRDye800)m utilizes the high photon count provided by an NIR fluorescent dye, IRDye 800CW, and the radioactive signal from a gamma emitter, Indium-111, for possible detection of HER2 metastasis in lymph nodes. We show that the accumulation and clearance of (111In-DTPA)n-trastuzumab-(IRDye800)m from the axillary nodes of mice occurs 48 h after intradermal injection into the dorsal aspect of the foot. The requirement for long clearance times from normal, cancer-negative nodes presents challenges for nuclear imaging agents with limited half-lives but does not hamper NIR optical imaging.