An integrated PET-CT scan combines the images from a positron emission tomography (PET) scan and a computed tomography (CT) scan, performed at the same time on the same machine. Together, the two scans create a more complete image than either test can offer alone.

Like the individual tests that it combines, an integrated PET-CT scan is a diagnostic examination used to detect cancer and find out the cancer’s stage (a way of describing a cancer, such as where it is located, whether or where it has spread, and whether it is affecting the functions of other organs in the body).

Staging helps the doctor decide what kind of treatment is best and predict a patient’s prognosis (chance of recovery). The scan can also be used to locate an area for a biopsy (the removal of a small amount of tissue for examination under a microscope to determine whether cancer is present) or to evaluate the effectiveness of cancer treatments, such as surgery, chemotherapy or radiation therapy.