Photodynamic therapy for thoracic malignancies

Photodynamic therapy (PDT) is an experimental form of cancer therapy which employs photoactivation of a sensitizing chemical by light of a given wavelength via the production of toxic oxygen species. PDT causes local destruction of cancer, and relies on a therapeutic index between normal and malignant tissue since the latter seems to selectively retain the sensitizer. PDT has both direct tumoricidal effects as well as indirect effects on tumor vasculature causing an early hemorrhagic necrosis of tissue. The treatment has been used for the treatment of endobronchial obstruction by primary and metastatic tumors. Most recently, trials are being performed to evaluate this therapy as a surgical adjunct in the treatment of pleural malignancies such as mesothelioma.