PHOTODYNAMIC DIAGNOSIS OF UROTHELIAL NEOPLASMS FOLLOWING INTRAVESICALINSTITUTION OF 5-AMINOLEVULINIC ACID

Following transurethral resection of bladder cancer, the fate of patie nts is clearly related to the presence or absence of precancerous or m alignant lesions in the remaining mucosa. We report on a new procedure for in situ diagnosis of these flat, hardly visible urothelial lesion s. The method is based on tumor-selective accumulation of endogenous p rotoporphyrin IX following intravesical instillation of 5-aminolevulin ic acid. On excitation with violet light even tiny papillary tumors, d ysplastic lesions and carcinoma in situ are bright fluorescing red. In 15 patients 26 neoplastic lesions had been diagnosed only by protopor phyrin IX fluorescence. False-negative results have not yet been obser ved. In 84% of 285 evaluable specimens the fluorescence findings corre sponded correctly with the microscopic findings. It is expected that p hotodynamic diagnosis will become a matter of routine in detection of bladder cancer.