Photodynamic diagnosis with 5-aminolevulinic acid in the treatment of secondary urethral tumors: first in vitro and in vivo results.

Abstract

Photodynamic diagnosis (PDD) is able to detect dysplasia and transitional cell cancer of the bladder. We report our first experiences using PDD in the urethra. Three patients with secondary transitional cell cancer of the urethra were treated by using PDD. 5-Aminolevulinic acid (ALA) was applied in a mixture with lubricant to achieve long enough contact with the urothelium. Negative effects were tested in vitro on three bladder cell lines. In vitro assays showed no enhanced negative effects on the viability of bladder cells using the combination of ALA/lubricant and medium in comparison to lubricant/medium alone. All patients showed markedly fluorescent areas, which were resected. The treatment was well tolerated without side effects attributable to the photosensitizer containing lubricant. Lubricant with ALA forms a viscous solution, which can successfully be used for PDD in the urethra. Thus marking tumors by fluorescence may improve transurethral resection and thus preserve the urethra.