 The purpose of this study is to test the safety of giving external beam radiation, followed by a Cyberknife radiosurgery boost at different dose levels, together with a chemotherapy drug called capecitabine. The dose of Cyberknife radiosurgery boost will be made higher slowly in this protocol. Patients with hilar cholangiocarcinoma Klatskin tumor, which is not amenable for surgical removal, are eligible. 