Does new photosensitizer improve photodynamic therapy in advanced esophageal carcinoma?

Abstract

Background and Objective: Polyhematoporphyrin (Photosan®) as sensitizers for photodynamic therapy (PDT) in advanced esophageal cancer carry the risk of prolonged photosensitivity of the skin. New 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 Photosan® for PDT in advanced esophageal carcinoma regarding phototoxicity of the skin, reduction of dysphagia, tumor stenosis, and tumor length and Karnovsky performance status. Study Design/Patients and Methods: After diagnostic work-up, photosensitization was done in 22 patients with ALA (60 mg/kg body weight, oral, 6-8 hours prior to PDT) and in 27 patients with Photosan® (2 mg/kg body weight, i.v., 48 hours before PDT). The light dose was calculated as 300 J/cm fibre tip. Light at 630 nm was applied using a pumped dye laser. In both groups, additional hyperbaric oxygenation was applied at a level of 2 absolute atmospheric pressure. Results: Improvement regarding dysphagia, stenosis diameter, and tumor length could be obtained in both treatment arms with a significant difference in favour of the Photosan®-group, P=0.02; P=0.0000; and P=0.000014, respectively. The Karnovsky performance status also improved in both groups and showed no significant difference (P=0.12). The median survival time for the ALA-group was 8.0 months, compared with 9.0 months for the Photosan® group. No sunburn or other major treatment related complication occurred in both treatment arms. Thirty-day mortality was 0%. Conclusion: Despite the limitations of a non-randomized study, photosensitzation with Photosan® seems to be more effective in PDT of advanced esophageal carcinoma compared to ALA. © 2001 Wiley-Liss, Inc.