Photodynamic therapy in lung cancer.

Photodynamic therapy (PDT) involves the use of photosensitizing agents that are selectively retained within tumor cells. The agents remain inactive until exposed to light of the proper wavelength. When activated by light, these compounds generate toxic oxygen radicals that result in tumor necrosis. In lung cancer, PDT can be used for both carcinoma in situ and for the treatment of unresectable disease with endobronchial obstruction. For patients with advanced disease, careful patient selection and integration of PDT with other interventional techniques are critical. Limited data suggest that PDT is comparable in efficacy to neodymium-yttrium-aluminum garnet (Nd-YAG) laser therapy, and some evidence indicates that it may be superior in terms of duration of response. For PDT to be used effectively, it should be integrated into a multimodality approach with chemotherapy and radiation. The optimal sequencing of these treatment modalities remains an area for further investigation.