http://repub.eur.nl/res/aut/5678/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/7127/ 2005-11-30T00:00:00Z Since Barrett’s oesophagus is a major risk factor for developing oesophageal adenocarcinoma, most centres have implemented endosocopic biopsy surveillance programs to detect precursor stages of adenocarcinoma (i.e. low grade dysplasia (LGD) and high grade dysplasia (HGD)). There is much interest in non-invasive, low-risk, ablative techniques that can eliminate precursor stages or early invasive cancer, since oesophagectomy, mostly performed once HGD or invasive cancer has developed, confers a high mortality and morbidity. The most commonly used techniques are thermal destruction by argon plasma coagulation (APC) and photochemical destruction by photodynamic therapy (PDT). Photochemical ablation using PDT is based on an intracellular accumulation of the photosensitizer protoporphyrin IX (PpIX) in tissue. There are different photosensitizers. The most common used are an enriched form of hematoporphyrin (Photophrin) and 5-aminolevulinic acid (ALA). ALA is a precursor molecule in the heme biosynthetic pathway that induces an endogenous production of PpIX. Photophrin is given to patients intravenously, whereas ALA is administered orally. PpIX is activated by photo-irradiation using laser light with an appropriate wavelength. This generates singlet oxygen production resulting in tissue destruction. APC employs a cautery probe that transfers electrical energy through ionized, electro conductive plasma of argon gas to the tissue surface, again resulting in tissue destruction. http://repub.eur.nl/res/pub/8296/ 2004-01-01T00:00:00Z BACKGROUND: Photochemical and thermal methods are used for ablating Barrett's oesophagus (BO). The aim of this study was to compare 5-aminolevulinic acid induced photodynamic therapy (ALA-PDT) with argon plasma coagulation (APC) with respect to complete reversal of BO. METHODS: Patients with BO (32 no dysplasia and eight low grade dysplasia) were randomised to one of three treatments: (a) ALA-PDT as a single dose of 100 J/cm(2) at four hours (PDT100; n = 13); (b) ALA-PDT as a fractionated dose of 20 and 100 J/cm(2) at one and four hours, respectively (PDT20+100; n = 13); or (c) APC at a power setting of 65 W in two sessions (APC; n = 14). If complete elimination of BO was not achieved by the designated treatment, the remaining BO was treated by a maximum of two sessions of APC. RESULTS: Mean endoscopic reduction of BO at six weeks was 51% (range 20-100%) in the PDT100 group, 86% (range 0-100%) in the PDT20+100 group, and 93% (range 40-100%) in the APC group (PDT100 v PDT20+100, p<0.005; PDT100 v APC, p<0.005; and PDT20+100 v APC, NS) with histologically complete ablation in 1/13 (8%) patients in the PDT100 group, 4/12 (33%) in the PDT20+100 group, and 5/14 (36%) in the APC group (NS). Remaining BO was additionally treated with APC in 23/40 (58%) patients. Histological examination at 12 months revealed complete ablation in 9/11 (82%) patients in the PDT100 group, in 9/10 (90%) patients in the PDT20+100 group, and in 8/12 (67%) patients in the APC group (NS). At 12 months, no dysplasia was detected. Side effects (that is, pain (p<0.01), and nausea and vomiting (p<0.05)) and elevated liver transaminases (p<0.01) were more common after PDT than APC therapy. One patient died three days after treatment with PDT, presumably from cardiac arrhythmia. CONCLUSION: APC alone or ALA-PDT in combination with APC can lead to complete reversal of Barrett's epithelium in at least two thirds of patients when administered in multiple treatment sessions. As the goal of treatment should be complete reversal of Barrett's epithelium, we do not recommend these techniques for the prophylactic ablation of BO.