Treatment of Primary Breast Cancer Using PDT

Verteporfin (which is marketed under the brand name Visudyne) is the photosensitizer. Verteporfin is a benzoporphyrin derivative which is clinically active when formulated with liposomes. By itself the clinically recommended dose of Verteporfin is not cytotoxic. It produces cytotoxic agents only when activated by light in the presence of oxygen. When energy absorbed by the porphyrin is transferred to oxygen, highly reactive short lived singlet oxygen is generated. Singlet oxygen causes damage to biological structures, leading to local vascular occlusion, cell damage and cell death.