Cyberknife Radiosurgery Boost for Hilar Cholangiocarcinoma (Klatskin Tumor)

This is a dose escalation study which will escalate the dose of Cyberknife radiosurgery boost after external beam radiation of 45 Gy with concurrent capecitabine. The three dose levels are 4 Gy x5, 5 Gy x5 and 6 Gy x 5, with 3 patients at each dose level. Dose-limiting toxicity (DLT) is defined as acute grade 3 liver or intestinal toxicity or any acute grade 4 toxicity. If one patient experienced a DLT at a particular dose level, the cohort should be expanded to 6 patients. The maximum tolerated dose (MTD) is defined as the dose level below that which results in DLT in 2 or more of the 6 patients in each cohort. At least 5 patients should be enrolled in the cohort of 6 Gy x 5 even if none of the first 3 experienced DLT, as a means of added verification of dose tolerance, at this upper limit of dose for this study. The patient population includes any patients who have unresectable hilar cholangiocarcinoma without any prior history of radiation. We anticipate accruing 1 patient every 2 months; therefore, we estimate that it will require approximately 22 months to accrue 11 patients if no DLT is experienced by any patients requiring expansion of the cohorts.