[en] From April 1987 through March 1992, 67 patients with carcinoma of the biliary system were treated with radiation therapy, 23 with carcinoma of the gallbladder (GB), 40 with carcinoma of the biliary tract and 4 with carcinoma of the ampulla of Vater. Sixty-three were treated by external radiation therapy (ERT) alone, 3 were treated by both ERT and intraluminal radiation therapy (ILRT), and the remaining one was treated by ILRT alone. The median survival time was 268.3 days, and survival rates at 1, 2, 3 and 5 years were 37.8%, 16.4%, 9.8%, and 3.3%, respectively. Only patients in whom GB polyp or GB stone had been diagnosed before operation and in whom carcinoma cells were found only on pathological examination were expected to have long term survival. No patient with unresectable GB carcinoma survived over 7 months. Eight patients with GB carcinoma who received postoperative ERT (40 Gy ≤) survived longer than GB carcinoma patients who did not. Eighteen patients with carcinoma of the biliary tract who underwent ERT (50 Gy ≤) survived significantly longer than 22 patients who did not. However, even among the former, few survived more than 2 years. Three of 4 patients with carcinoma of the ampulla of Vater are alive at 1, 8 and 24 months at present. No significant difference was recognized between the survival rates of 4 patients with carcinoma of the biliary tract who received ILRT and those patients who underwent ERT alone. The analysis of this and other reports indicates the need to devise the planning of ERT and to combine ILRT with ERT to prevent adjacent organs from suffering radiation injury and in order to concentrate a high dose on the focus. (author)