Photodynamic therapy (PDT) is a treatment that uses a combination of a light-sensitive drug and laser light. The two work together to destroy cancer cells. During PDT, patients receive an injection of the light-sensitive drug Photofrin®. While both normal cells and cancer cells absorb the drug, it rapidly leaves healthy tissue, remaining in only the cancerous cells. Exposed to laser light, the drug becomes "activated" and reacts with oxygen in the cell. This reaction produces a singlet oxygen molecule that kills cancer cells, leaving healthy cells unharmed.
The Ireland Cancer Center presently uses PDT for specific cancers of the esophagus and lung or bronchial system. The Ireland Cancer Center has begun testing a new photosensitizing drug, Pc4, for cutaneous malignancies.