Energy from the laser light is absorbed by the photosensitizer. Tissue penetration is limited to a few millimeters in this method. This fact and the relatively low power used prohibit complete eradication of large obstructing airway lesions. Superficial tumors are usually squamous cell carcinomas that are radiographically occult. They are often detected through cytologic examination of sputum.
Surgical resection remains the best treatment for early-stage lung cancer.
Three patients who had recurrence after complete response underwent surgical resection, and no evidence of nodal metastasis was found. Photodynamic therapy begins with intravenous administration of hematoporphyrin derivative 2 to 3 days before laser irradiation is planned. For argon laser application, the patient is given a general anesthetic or topical anesthetic sufficient to prevent coughing. The appearance of the irradiated area is unchanged immediately after treatment, but within 6 to 48 hours, edema, swelling, and necrosis occur. Significant coughing, wheezing, and dyspnea may develop.