The hypothesis of this lab protocol is that topical application of the anti-EGFR and anti-telomerase fluorescent contrast agent followed by optical imaging will yield images that reflect spatial variations in EGFR and telomerase expression and will correlate with the presence of esophageal precancer as assessed by histopathology. To test this hypothesis we will:
1. Obtain specimens of Barrett's mucosa from patients undergoing routine surveillance endoscopy for Barrett's esophagus. Patients with Barrett's esophagus typically undergo endoscopy at 3 month-3 year intervals depending upon the grade of their dysplasia. In the routine clinical care of patients with Barrett's esophagus, 4 biopsies are taken every 1-2 cm throughout the length of Barrett's esophagus. These will be submitted to the pathology department as part of the patient's routine clinical care and will not be used for research. For purposes of the study, an additional biopsy will be taken from each level of Barrett's esophagus, plus 1-2 biopsies of normal squamous mucosa.
2. Immediately after obtaining the study specimens, low-resolution optical images will be obtained of the samples using a multispectral digital microscope (MDM) which records the light remitted from the tissue surface. High resolution optical images will then be obtained from suspicious areas using a confocal microscope. The spectral characteristics of the suspicious lesions will be measured using a spectroscopy system.
3. Immediately after imaging, spectroscopy measurements, and biopsy, the contrast agent(s) will be applied to the epithelial surface of the tissue.
4. After 30 minutes, the tissue will be rinsed with PBS and low resolution optical images will be obtained using a multispectral digital microscope (MDM), which records the light remitted from the tissue surface. High resolution optical images will be obtained from suspicious areas using a confocal microscope. The spectral characteristics of the lesions will be measured using a spectroscopy system. |