Enhanced contrast dual modality imaging approach for screening of epithelial cancers

A novel approach for epithelial cancer screening based on the use of a high specificity cancer targeting contrast agent in combination with a dual imaging capability, fluorescence guided optical coherence tomography (OCT), is presented. An RGD peptide labeled with a NIR fluorescent carbocyanine dye (cypate) is used as a contrast agent for fluorescence imaging. The RGD peptide recognizes the α_vβ₃ integrin receptor (ABIR) which is over-expressed by epithelial cancer cells. While OCT allows detailed probing of subsurface tissue structures with resolution on the order of microns, it is associated with a limited field of view, on the order of millimeters, and thus screening of large organs is not very practical because involves the time-consuming analysis of very large data sets. The use of a guidance tool, like enhanced contrast fluorescence imaging, can help to highlight the presence of suspicious lesions. Therefore, OCT imaging can be performed only on the suspicious lesions as a confirmatory tool. A detailed description of this technology and preliminary results on excised colon tissue samples are presented.