[1]Department of Radiation Oncology Hallym University Sacred Heart Hospital Anyang 14068 South Korea;
[2]Department of Radiation Oncology Hanyang University College of Medicine Seoul 04763 South Korea;
[3]Department of Radiation Oncology Ewha Womans University College of Medicine Seoul 07985 South Korea;
Extrahepatic bile duct cancer; Patterns of failure; Adjuvant radiotherapy; Definitive radiotherapy; Palliative radiotherapy; Biliary stent;