<title>5-ALA-assisted photodynamic therapy in canine prostates</title>

Abstract

Photodynamic therapy (PDT) and interstitial thermotherapy are well known treatment modalities in urology. The approach of this study is to combine both to achieve a selective treatment procedure for benign prostatic hyperplasia (BPH) and prostate carcinoma. Measurements of thy in-vivo pharmacokinetics of 5-ALA induced porphyrins by means of fiber assisted ratiofluorometry showed a maximum fluorescence intensity at time intervals of 3 - 4 h post administration. Fluorescence microscopy at that time showed bright fluorescence in epithelial cells while in the stroma fluorescence could not be observed. Interstitial PDT using a 635-nm dye laser with an irradiation of 50 J/cm² resulted in a nonthermic hemorrhagic lesion. The lesion size did not change significantly when an irradiation of 100 J/cm² was used. The usefulness of PDT for treating BPH as well as prostate carcinoma has to be proven in further studies.