Abstract

Photodynamic therapy (PDT) represents a new approach to treatment of a variety of malignant tumors in man and animals.¹ A nontoxic photosensitizing drug with fluorescent properties, like the hematoporphyrin derivative (HpD), is first injected systemically. After 2-3 days, this drug exhibits a higher retention in the cancer region than in the surrounding normal tissue. Subsequent irradiation with a proper optical wavelength, mainly red around 630 nm, results in rapid necrosis of the neoplastic tissue.

© 1986 Optical Society of America