Bronchoscopic photodynamic diagnosis and therapy for lung cancer.

Photodynamic diagnosis and therapy have exciting potential in lung cancer management. Fluorescence bronchoscopy enhances the detection of preinvasive lesions and early invasive carcinomas involving the central airways, whereas photodynamic therapy (PDT) provides an effective method for treating these lesions with preservation of lung tissue. However, the natural history of preinvasive lesions is poorly understood and so the value of treatment remains unclear. Although treatment for early invasive carcinomas'is not open to question, the possibility of undetected nodal disease means that PDT is unlikely to replace surgical resection in patients who are fit for thoracotomy. PDT also provides an effective method of palliating patients with advanced obstructing endobronchial tumors. Although it is considered superior to simple tumor debulking, its usefulness is limited by transient but potentially severe skin photosensitivity. There is therefore a need to develop new photosensitizing drugs with less severe side effects.