Photodynamic therapy

Abstract

Photodynamic therapy is a nonsurgical therapeutic option for the management of endobronchial tumors. It involves intravenous injection of a photosensitizing drug, followed by direct application of a nonthermal laser. The laser provides the wavelength of light to activate the drug in the tumor. Once activated, the drug causes cell death through oxygen free radical generation, small vessel thrombosis, and a tumor-specific cytotoxic immunity. The necrotic debris should be removed by bronchoscopy to avoid airway obstruction. Photodynamic therapy is currently indicated in patients with microinvasive endobronchial non-small cell lung cancer (NSCLC) and comorbidities that render them ineligible for surgical resections, where it is used with a curative intent and in patients with completely or partially obstructing endobronchial NSCLC who require debulking of the airway tumor for palliation of symptoms. Photodynamic therapy is also useful in debulking endobronchial metastatic lesions from nonpulmonary malignancies. The major adverse reaction following PDT is skin photosensitivity that can be avoided with meticulous pre- and postprocedure patient education. Other adverse reactions include transient local inflammatory response, airway stenosis at the site of treatment, and, rarely, massive hemoptysis. The utility of PDT in the management of lung cancers is only expected to expand as newer photosensitizing drugs are developed.