The establishment of a registry to capture all PDT cases within and outside US can help the investigators evaluate a larger and non-ambiguous sample population. This would help the investigators evaluate the technical success rates, clinical success rates, feasibility and safety of PDT for unresectable cholangiocarcinoma. With more endoscopists considering PDT as a therapeutic option along with adjuvant treatment for cholangiocarcinoma, there is a need to further evaluate the efficacy and safety of such combined procedures as well. The ultimate objective is to assess if PDT with or without additional or adjuvant treatment options prolongs survival duration and improves quality of life in patients with unresectable cholangiocarcinoma.