The Cross Cancer Institute has recently acquired a tomotherapy radiotherapy treatment machine; the first of its kind in Canada. It has the potential to improve cancer treatment outcomes where radiotherapy is used. Cervix cancer is a disease where radiotherapy is a particularly important treatment modality. The researchers believe that by combining tomotherapy (which has the ability to give higher doses of radiation to areas of cancer while sparing normal tissues) with radiotherapy given from inside the uterus and vagina (brachytherapy) disease outcomes will be improved. For this to be possible the researchers will need to accurately map the doses of radiation given to the cervix, uterus and other pelvic organs from these two types of radiation treatment. As well as being used for treatment, the tomotherapy machine can also be used for taking medical images by using very much lower doses of radiation. This study will allow the researchers to develop the mapping process by using very low doses of radiation on the tomotherapy unit to take medical x-ray images of patients being treated by brachytherapy for cervix cancer. In this special circumstance the researchers expect the images to be of a higher quality than for conventional computed tomography (CT) scanning or magnetic resonance imaging (MRI) scanning.