Positron emission tomography (PET) scans uses glucose (a form of sugar) that contains a radioactive atom. Cancer cells in the body absorb large amounts of the radioactive sugar and a special camera can detect the radioactivity. This test can help see if the cancer has spread to lymph nodes. PET scans can also be useful if your doctor thinks the cancer has spread but doesn’t know where. PET scans can be used instead of other types of x-rays because they scan your whole body. PET scans are often combined with CT scans using a machine that can do both at the same time. The CT/PET test is rarely used for patients with early cervical cancer, but may be used to look for more advanced disease. .