Photodynamic therapy of rat bladder and urethra: evaluation of urinary andreproductive function after inducing protoporphyrin IX with 5-aminolaevulinic acid

Objective To assess the urinary and reproductive function of rats after ind ucing protoporphyrin IX with 5-aminolaevulinic acid (ALA) and subsequent in traurethral photodynamic therapy (PDT). Materials and methods Twelve female Wistar rats were given ALA orally or in travesically (four each), followed by intraurethral PDT through a 10-mm cyl indrical fibre at 100 mW for 500s (argon laser, 632 nm). Urinary frequency, the number of gestations and histological changes were then evaluated and compared with a group of eight control rats. Results There was only a slight increase in urinary frequency during the fi rst 2 weeks after PDT in the group given oral ALA, while the same degree of urinary frequency was evident for up to 4 weeks in those given intravesica l ALA. Despite the occurrence of urinary incontinence from undefined causes in two rats, reproductive function remained unchanged. There was no histol ogical evidence of damage to the reproductive system adjacent to the bladde r. Conclusions PDT of the urethra with ALA is relatively safe and carries few risks of inducing permanent urological complications.