Endoscopic management of bladder cancer with hematoporphyrin derivative phototherapy.

The propensity of hematoporphyrin derivative (HpD) to fluoresce in the red portion of the spectrum when exposed to near-ultraviolet light has enabled investigators to substantiate that HpD selectively localizes in dysplastic and neoplastic urothelial cells. More important from a clinical standpoint is the cytotoxicity that occurs when cells that have absorbed HpD are exposed to light of wavelengths that correspond to its absorption bands. Several early clinical studies have substantiated the potential clinical usefulness of HpD phototherapy.