Cholangiocarcinoma is a catastrophic tumor with a high mortality rate, for which surgery is the most reliable treatment. However, these tumors progress insidiously and are difficult to diagnose early. Most patients lack the opportunity to receive surgery due to the advanced disease stage at the time of the diagnosis, at which point only few alternative treatments are available. There is a need for more effective therapy to improve the survival or quality of life of these patients. The present case was a 73-year-old male who presented with jaundice and fatigue underwent CT imaging, in which a 3.5×4.0-cm low-attenuation mass was found in hepatic segment 4. Cholangiocarcinoma was diagnosed by cytological examination of the bile juice. A combination of CyberKnife radiosurgery and S-1 oral chemotherapy was performed. The patient was alive at a 8-month follow-up, and serial CT scans revealed a markedly regressed tumor. Therefore, we suggest that concurrent chemoradiation with the CyberKnife and S-1 is a treatment option for advanced cholangiocarcinoma. (Gut Liver 2010;4:103-105)

Cholangiocarcinoma is the primary malignant tumor of the bile ducts which originates from cholangiocytes. 1 Surgical resection is the only curative therapy. Unfortunately, due to lack of symptoms until late in the disease, the majority of patients present with unresectable disease, typically resulting in advanced cholangiocarcinoma at the time of diagnosis. In addition, advanced age, poor performance status, acute illness, and/or systemic disease are considered inoperable in many cases. 2,3 In particular, in hilar cholangiocarcinoma, primary invasion of the portal vein and metastasis to the hepatic lobes occurs so frequently that surgical resection is impossible, and it is associated with a poor prognosis. 4 Biliary