Photoradiation Therapy with Hematoporphyrin Derivative and an Argon Dye Laser of Bladder Carcinoma

Abstract

Hematoporphyrin Derivative (HpD) which has an affinity for malignant tumors is excited by light exposure and reacts photodynamically in tumor tissue. Therefore it is possible to treat malignant tumor selectively without any damage to surrounding normal tissues. HpD is excited by a light in the spectrum from ultraviolet to visible red. Previously arc lamps and slide projectors were used for excitation of HpD but laser beams which facilitate photoradiation via endoscopes has been used recently. Much of the early basic and clinical studies on HpD and light photoradiation therapy was performed by Dougherty and his coworkers1. Hayata et al. investigated photoradiation therapy using an argon dye laser following an intravenous HpD administration in mice, and on cultured human lung cancer cells2, and in experimentally induced canine lung cancer and demonstrated its therapeutic effectiveness3. Malignant bladder tumor were treated by this new technique in this study.