The Effect of Transurethral Light on the Canine Prostate after Sensitization with the Photosensitizer Tin (II) Etiopurpurin Dichloride: A Pilot Study

Abstract

A pilot study was undertaken to determine the effect of transurethral light on photosensitized periurethral prostatic tissue in the dog. Initial studies demonstrated that a sufficient level of the photosensitizer tin (II) etiopurpurin dichloride, SnET2, was present in the canine prostate 24 hours after intravenous administration to create a photodynamic effect. Gross and histologic examination of SnET2 photosensitized prostates treated transurethrally with 285 joules per cm. of red light (660 nm.) showed hemorrhagic necrosis as much as 1 cm. from the urethral wall. Three weeks after treatment, circumferential glandular atrophy was evident within the treatment area. The urethral mucosa, which was histologically absent at the 48-hour interval, regenerated by 3 weeks. Transurethral photodynamic treatment of the prostate is feasible, and its use for the treatment of benign prostatic hyperplasia warrants further investigation.