Radiotherapy in combination with chemotherapy is the standard treatment of locally advanced cervix cancer, however with traditional techniques large volumes of bowel and bladder are irradiated causing short-term and long-term genito-urinary and gastro-intestinal side effects. IMRT has the potential to conform precisely to the target and spare normal tissues and reduce side effects. However because there are large dose gradients there is the potential to miss the target due to organ motion. Recent studies have documented organ motion and will be used to define the target. Approximately 60 planning scans, previously used to treat patients with cervix cancer, will be used to replan using an IMRT technique and differences in doses to tumour and normal tissues compared.