In this case report, radiation therapy was performed for bilateral hydronephrosis developed during multiple bone metastases of breast cancer and ileus due to peritoneal dissemination. The patient’s preirradiation creatinine level was 8.2 mg/dL, which decreased by the fourth day after starting irradiation therapy. Creatinine level ultimately decreased to 0.6 mg/dL. Pain due to lumbar spine metastasis alleviated and ileus was resolved, allowing the patient to live at home for approximately 5 weeks. The effect of radiotherapy for bilateral hydronephrosis and gastrointestinal obstruction was rapid and good. Palliative radiation treatment can be used for multiple purposes, and in the present patient, we were able to prolong the vital prognosis.
