PDT offers a number of practical advantages; it is minimally invasive and has a low complication rate, the procedure can easily be performed by a trained endoscopist, and it is well tolerated. In the trial conducted in Germany, the adverse events of PDT were mild to moderate, predictable, and relatively easy to control. Photosensitivity was the only systemic side effect (seen in only three patients). However, provided that simple guidelines for light exposure are followed, there is minimal risk to the patient, as shown by the low incidence of photosensitivity reactions in this study which all resolved.