My Mother Has Stage IV Breast Cancer That Has Spread To The Bone And Liver

Stage IV Breast Cancer that has spread to the bone and liver My mother has recently been diagnosed with Stage IV Breast Cancer. It has spread to her bone and liver. She is in a great deal of pain due to the tumors pressing against her spinal chord. Her doctor has decided to treat her with radiation and chemo. They told her that they would begin with radiation in order to shrink the tumors on her spine, which are causing the pain, and that after the first week of treatment, she should start feeling a lot better, that the pain would "go away". She is now in her third week of radiation and she seems worse off then when she started. Is this a sign that the radiation is not working? That it is not shrinking the tumors?