Photodynamic therapy for cholangiocarcinoma using low dose mTHPC (Foscan®)

Background: Photodynamic therapy (PDT) combined with stenting is an effective treatment modality for palliation of nonresectable cholangiocarcinoma (CC). A drawback of standard PDT using Photofrin (R) as photosensitizer is the long lasting skin photosensitivity of up to 3 months. The aim of this study was to show the outcome of PDT of CC, potential side effects and to determine the best drug light interval (DLI) using mTHPC (Foscan (R)) at a low dose. Methods: 13 patients with nonresectable CC were treated with stenting and PDT (3 mg Foscan (R) per treatment, 0.032-0.063 mg/kg body weight, 652 nm, 50 J/cm). Fluorescence measurements were performed with a single bare fiber for 5/13 patients prior to PDT at the tumor site to determine the fluorescence contrast. For another 7/13 patients, long-term fluorescence-kinetics were measured on the oral mucosa to determine the time of maximal relative fluorescence intensity. Results: The results so far indicate a median survival time of 13 months. Side effects such as perforations or skin phototoxicity could not be observed. Foscan (R) fluorescence within the tumor site was clearly detectable but a significant fluorescence contrast of tumor to adjacent healthy tissue could not be found. The fluorescence kinetics measured in the oral mucosa showed a maximum at 3.85 days (median) after drug administration. Conclusion: Combined stenting and PDT performed with a low Foscan (R) dose results in equal and potentially longer survival times compared to standard Photofrin PDT, while lowering the risk of side effects strongly. Thus it may improve the quality of life. (C) 2013 Elsevier B.V. All rights reserved.