CT Scans are Computed Tomography scans, also commonly known as CAT scans. It is an imaging tool that uses special x-rays to create detailed pictures of areas inside the body. In addition to its numerous medical applications, CT scans can help detect cancer in the body as well as provide the extent of growth and/or invasion into nearby structures. The information gathered from a CT scan helps provide a lot of useful information that can be used for treatment of cancer. For instance, CT scans help approximate where surgery should be performed to remove the tumor. It also helps plan external beam radiation therapy, as well as determine whether the tumor is responding to treatment.