Photodynamic diagnosis (PDD) of bladder cancer with intravesical 5-aminolevulinic acid induced fluorescence

摘要

Flat urothelial lesions as well as small papillary tumors are easily missed during trasnurethral resection (TUR). PDD is based on the detection of protoporphyrin-IX induced fluorescence after topical administration of 5-aminoevulinic acid (ALA). We report on our initial clinical results of 130 procedures in 98 patients. Two hours prior to TUR 1.5 g ALA dissolved in 50 ml 1.4percent NaHCO-3 solution was installed intravesically. For fluorescence excitation a blue light source (375-440nm, Karl Storz) was used. In total 478 biopsies (2-9 per patient) were taken from fluorescent and nonluorescent areas. Normal nonfluorescnet bladder urothelium was blue, whereas cancer epithelium developed a brilliant red fluorescence. During white light cystoscopy, 143 bladder tumors were found. Sixty-three additional tumors were detected because of their positivie fluorescence. The overall sensitivity of fluorescence cystoscopy (98percent) was greater than that of white light cystoscopy (69percent). Their specificities were 51percent and 80percent respectively. Despite positive fluorescence 133 biopsies were found to be benign. Histological analysis of the tissue specimens showed deviant tissue in 54 times of the cases. At least a partof these lesions are precancerous. Tumor-associated ALA-induced fluorescence offers new perspectives in the diagnosis of bladder cancer. The procedure has a high sensitivity for superficial bladder cancer and decreases the number of overlooked lesions.