Luminescence imaging and spectroscopy for the detection of early neoplasia in Barrett’s esophagus

The motivation for this thesis rose from the demand to improve the early detection and identification of neoplastic tissue in Barrett’s esophagus. Barrett’s esophagus (BE) is a potential precursor of adenocarcinoma which occurs in the distal part of the esophagus. The prognosis of patients diagnosed with adenocarcinoma is poor, only early detection can lead to early treatment and therefore improve the outcome. With this thesis we explored new luminescence imaging and spectroscopy methods to improve the detection of early neoplasia in BE.
In the first part we evaluated in-vivo a new autofluorescence imaging (AFI) endoscope to target specific fluorophores. Because the newest generation AFI endoscope specifically targets fluorescence in malignant cells, it may improve the detection of early neoplasia and reduce the false-positive rate. Thereafter, we used autofluorescence spectroscopy at single wavelength excitation incorporated into a standard biopsy forceps in order to further improve the early detection of neoplasia in BE and to reduce the amount of unnecessary taken biopsies. To further determine the optimal excitation and emission wavelengths we built and evaluated in-vivo a multi-wavelength spectroscopy system compromising five different excitation wavelengths.
In the last part of the thesis, two pre-clinical studies for ‘exogenously induced’ enhanced tissue contrast were performed. We evaluated the chorioallantoic membrane (CAM) model for the usage of fluorescence diagnostic and photosensitizer on human BE tissue. BE biopsy specimens were grafted on the CAM and followed up to 9 days. Furthermore we used the CAM model for targeted labeling of early-stage cancer with upconversion nanoparticles.