Abstract: A safer, improved method of photodynamic therapy is provided for treating diseased, hyperproliferative tissue, including cancer, psoriasis, and arthritis, using multiple, sequential administrations of a photosensitizer (PS) prior to irradiation. Preferred photosensitizers are characterized by being retained in the diseased tissue for a longer time than in normal tissue. The interval between administrations is chosen to be of sufficient duration to allow the PS content of normal tissues to drop to a basal or negligible level before the next administration and before irradiation. At that time, the PS content of the diseased tissue is still high, not less than half of the initial content after the last PS administration. In this way, PDT with better selectivity for the diseased tissue is achieved. With sequential PS administrations, the PS burden on normal tissue can be kept low, so that side effects can be reduced, for example damage of the skin by sunlight or bright indoors artificial lighting.

Abstract: A safer, improved method of photodynamic therapy is provided for treating diseased, hyperproliferative tissue, including cancer, psoriasis, and arthritis, using multiple, sequential administrations of a photosensitizer (PS) prior to irradiation. Preferred photosensitizers are characterized by being retained in the diseased tissue for a longer time than in normal tissue. The interval between administrations is chosen to be of sufficient duration to allow the PS content of normal tissues to drop to a basal or negligible level before the next administration and before irradiation. At that time, the PS content of the diseased tissue is still high, not less than half of the initial content after the last PS administration. In this way, PDT with better selectivity for the diseased tissue is achieved. With sequential PS administrations, the PS burden on normal tissue can be kept low, so that side effects can be reduced, for example damage of the skin by sunlight or bright indoors artificial lighting.

Abstract: A pharmaceutical composition, method and apparatus for treatment, diagnosis or both treatment and treatment of hyperproliferative malignant and non-malignant diseases of epithelial tissues is disclosed. The invention comprises local application of the pharmaceutical composition to a predetermined area of the tissue characterized by complete and consistent coverage of the tissue, including irregularly shaped tissue. The pharmaceutical composition consists of an active component, such as a photosensitizer or a precursor thereof, and at least one carrier substance including a viscous fluid, a gel, or a fluid that becomes viscous upon contact with the tissue. The gel's viscosity allows it to adhere to the tissue for a sufficient amount of time to transfer the photosensitizer or precursor. In a preferred embodiment the pharmaceutical composition is sprayed onto the surface of the diseased tissue.