Photodynamic diagnosis in the gastrointestinal tract.

Clinical data on photodynamic diagnosis for the detection of premalignant and malignant lesions in the gastrointestinal tract are encouraging so far. A major benefit of using autofluorescence is the lack of side effects because no sensitizer has to be applied.However, highly sophisticated detection systems are needed to enhance the weak autofluorescence-based fluorescent signal. New prototypes of autofluorescence video endoscopes are under way and will be decisive for further clinical use, especially because results of recently published studies have been disappointing.