Photodynamic therapy for endobronchial malignancy: The minimal effective dose of photofrin

Purpose: Photosensitivity from Photofrin seems to be a dose-related phenomenon. For this reason, we sought to and the minimal effective dose in patients with endobronchial malignancy. Methods: Patients either received 1.5 mg/kg of Photofrin (Group 1.5, n=3), 1.0 mg/kg of Photofrin (Group 1.0, n=10) or 0.5 mg/kg (Group 0.5, n=7). 48 hours after injection, all patients were treated with light delivered via a .1 cm diffusing fiber from an argon-pumped dye laser at a wavelength of 630nm and an energy dose of 400J/cm of fiber. Patients were evaluated for response at 96 hours post-injection by bronchoscopy. Patients were also evaluated for photosensitivity generally resulting from noncompliance and for complications of therapy. Results: All patients in Group 1.5 exhibited a complete response (CR), defined as >90% relief of endobronchial obstruction. In Group 1.0, 7 patients exhibited a CR, and 3 patients exhibited a partial response (PR) defined as >50% relief of endobronchial obstruction. In Group 0.5, 5 patients exhibited a CR, however the remaining 2 patients exhibited no response (NR). 2/20 patients (10%) exhibited sunburn in Group 1.0. In Group 1.0, 1 patient developed transient upper airway obstruction requiring emergent bronchoscopy, and 1 patient developed pneumothorax after cleanout bronchoscopy. Massive hemoptysis was not observed. Conclusion: The dose of 1.5mg/kg of Photofrin is safe and reasonably effective; mild photosensitivity at this dose is seen occasionally in noncompliant patients.