Yttrium Y 90 Glass Microspheres and Capecitabine in Treating Patients With Liver Cholangiocarcinoma or Liver Metastases

RATIONALE: Radiation therapy uses high-energy x-rays and other types of radiation to kill tumor cells. Specialized radiation therapy, such as yttrium Y 90 glass microspheres that deliver a high dose of radiation directly to the tumor, may kill more tumor cells and cause less damage to normal tissue. Drugs used in chemotherapy, such as capecitabine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Capecitabine may also make tumor cells more sensitive to radiation therapy. PURPOSE: This phase I trial is studying the side effects and best dose of yttrium Y 90 glass microspheres when given together with capecitabine in treating patients with liver cholangiocarcinoma or liver metastases.