Sentinel lymph node involvement is recognized as a prognostic factor in breast cancer staging and is essential to guide optimal treatment. The possibility of missed micrometastases by using conventional methods was estimated around 20-60% cases has created a demand for the development of more accurate approaches. A paired-agent imaging approach is presented by employing a control imaging agent to allow rapid, quantitative mapping of microscopic populations of tumor cells in lymph nodes to guide pathology sectioning. To test the feasibility of this approach to identify micrometastases, lymph node micrometastases biological tissue model was developed and were stained with targeted and control imaging agent solution to evaluate the binding potential of the agents of intact nodes. ABY-029, an EGFR specific affibody was labeled with IRDye-800CW(LICOR) as targeted agent and IRDye-700DX was hydrolyzed as control agent. Lymph nodes phantoms were stained for 60 min, followed by 60 min rinsing, and the fluorescence of whole lymph node phantoms were recorded to evaluate the spatial distribution of both agents in the entire phantom. Measured binding potential of targeted agent between micrometastases and control regions were 0.652 ± 0.130 and -0.008 ± 0.042 respectively (p < 0.0001). The results demonstrate the potential to enhance the sensitivity of lymph node pathology using paired-agent imaging in a whole human lymph node.
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