Novel Endoscopic Imaging Methods for the Evaluation of Blood Vessels in Gastrointestinal Cancers

The aim of the project is to study the role of minimally invasive imaging methods, such as magnification endoscopy with narrow-band imaging (M-NBI) combined with confocal laser endomicroscopy (CLE), in correlation with immunohistochemical analysis, for assessing the angiogenesis status of patients with gastrointestinal tumors, in particular with colorectal and gastric cancer. Angiogenesis, i.e. the process of forming new blood vessels, represents an essential event for tumor growth and metastasis and the importance of its understanding stems from potential applications for diagnosis, prognosis stratification and mainly from the possibility of developing and improving targeted therapies. While current methods for evaluating tumor vascularity are based on immunohistochemistry techniques with microvascular density (MVD) calculations, these imply repeated tissue sampling and are not feasible in the context of clinical practice. Imaging techniques might overcome limitations associated with MDV measuring, obtaining both functional and morphological information and enabling repeated evaluations that are necessary for the assessment of a dynamic process as angiogenesis during follow-up of targeted therapies. NBI is a digitally enhanced endoscopic imaging technique that uses optical filters to illuminate tissue with light at blue and green wavelengths. These are selectively absorbed by hemoglobin and, as a result superficial vascular networks are highlighted and morphological changes in capillary patterns can be described for different lesions. CLE represents a revolutionary technology that enables endoscopists to collect real-time in vivo histological images or "virtual biopsies" of the gastrointestinal mucosa during endoscopy, and has raised significant interest for the potential clinical applications and numerous research possibilities. After intravenous administration of fluorescein as a contrast agent, CLE enables real-time visualization of the tumor vasculature, which is structurally and functionally altered compared to the normal vascular networks. Therefore M-NBI will be used for enhanced visualization of morphological changes of the superficial capillaries, while CLE will be directed towards vascular regions of interest for characterization of these changes at the microscopic level. Furthermore, imaging studies will be backed by MVD calculation using immunohistochemical methods, based on tissue samples harvested during endoscopic procedures.

Sex

All

Minimum age

18 Years

Maximum age

90 Years

Inclusion Criteria:

* Patients with gastric and colorectal cancer
* Age 18 to 90 years old, men or women
* Signed informed consent for M-NBI and pCLE examinations with tissue sampling.

Exclusion Criteria:

* Failure to provide informed consent
* Prior or ongoing chemo- and/or radiotherapy
* Patients with a contraindication for GI endoscopic procedures
* Known allergy to fluorescein

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