5-Aminolaevulinic acid compared to polyhematoporphyrin photosensitization for photodynamic therapy of malignant bronchial and esophageal stenosis: clinical experience.

Objective: Polyhematoporphyrins (PhP) as sensitizers for photodynamic therapy (PDT) in malignant bronchial and esophageal stenosis carry the risk of prolonged photosensitivity of the skin. New line sensitizers such as 5-aminolaevulinic acid (ALA) with low rates of skin phototoxicity appear to be promising alternatives. The aim of this study was to evaluate the efficacy of ALA compared to PhP for PDT regarding phototoxicity of the skin, reduction of tumour stenosis and tumour length and Karnofsky performance status.

Methods: After diagnostic work-up, photosensitization was done in 38 patients with ALA (60mg/kg body weight, oral, 6-8h prior to PDT) and in 51 patients with PhP (2mg/kg body weight, i.v., 48h before PDT). The light dose was calculated as 300J/cm fibre tip. Light at 630nm was applied using a pumped dye laser. In both groups, additional hyperbaric oxygenation was applied at a level of 2 bar absolute pressure.

Results: Improvement regarding stenosis diameter, tumour length and Karnofsky performance status could be obtained in both treatment arms with a significant difference in favour of the PhP-group, P = 0.00073; 0.000014, and 0.00015, respectively. No sunburn or other major treatment related complications occurred in either treatment arms.

Conclusions: Photosensitization with PhP compared to ALA seems to be more effective in PDT of malignant bronchial and esophageal stenosis.