Photodynamic therapy for Barrett's oesophagus with use of 5-aminolevulinic acid

Abstract

Barrett's oesophagus is a premalignant lesion of the oesophagus characterized by the presence of colunmar epithelium with intestinal metaplasia in the distal oesophagus. Oesophageal adenocarcinoma (the most rapidly increasing cancer in the Western world) is thought to originate from Barrett's oesophagus following a sequence from metaplasia through dysplasia to adenocarcinoma. To gain insight in the various aspects of Barrett's oesophagus, the state of the art of its pathophysiology, diagnosis and management is reviewed in Chapter 1, Part I, the general introduction of the thesis. Both endoscopic surveillance and oesophageal resection are recommended for patients with Barrett's oesophagus and high-grade dysplasia. Tins, however, is still controversial as the mortality and morbidity associated with oesophageal resection are considered to be high in view of a preneoplastic disease. Therefore, endoscopic ablation therapies, including photodynamic therapy, have been experimentally used to treat Barrett's oesophagus. The characteristics of the various endoscopic ablation therapies and their results are summarized in Chapter 2. The studies described in this thesis aim at making 5-aminolevulinic acidmediated photodynamic therapy clinically applicable for the endoscopic treatment of Barrett's oesophagus. For a better understanding of the experinlental chapters, Part I is completed with Chapter 3, outlining the fundamentals of 5-aminolevulic acid-based photodynamic therapy