What is PET/CT Imaging?
PET/CT imaging is a powerful oncology imaging tool that empowers physicians and patients with the information needed to develop the most clinically appropriate and viable treatment plans.
PET/CT imaging involves the fusion (or co-registration) of the results obtained from a positron emission tomography (PET) scan and a computed tomography (CT) scan performed as part of a single imaging exam.
The majority of PET/CT scans are performed for oncologic applications. Physicians utilize PET/CT scans for diagnosing, staging and evaluating treatments for their cancer patients.
When disease strikes, the biochemistry of cells and tissue changes. In cancer, for example, cells begin to grow at a much faster rate. In one continuous whole-body scan, PET/CT captures images of changes in the body’s metabolism caused by actively growing cancer cells, while also providing a detailed picture of the body’s internal anatomy that reveals the size, shape and exact location of the abnormal cancerous growths.
A PET scan helps the physician distinguish between living and dead tissue or between benign and malignant disorders. PET imaging provides the physician with additional information about cellular activity which guides the characterization of a questionable abnormality as malignant or benign.
A PET/CT scan puts time on your side. The earlier the diagnosis and the more accurate the assessment of the extent of disease, the better the chance for successful treatment.
How Is PET/CT Different?
Positron emission tomography (PET) and computerized tomography (CT) are both state-of-the-art imaging tools that allow physicians to pinpoint the location of cancer within the body before making treatment recommendations. The highly sensitive PET scan images the metabolic functioning of cells and tissue, while the CT scan provides a detailed picture of the body’s internal physical anatomy.
A hybrid PET/CT scan combines the strengths of these two well-established imaging modalities into a single scan with significantly improved diagnostic confidence and accuracy.
Computed Tomography (CT) Imaging
A CT scan is able to detect and localize changes in the body structure or anatomy, such as the size, shape, and exact location of an abnormal growth, a sizeable tumor, or a musculoskeletal injury.
Positron Emission Tomography (PET) Imaging
PET imaging allows physicians to distinguish between living and dead tissue or between benign and malignant disorders. Because a PET scan images the biology of disorders at the molecular level, it can help the physician detect abnormalities in cellular activity at a very early stage, generally before anatomic changes are otherwise detectable.
CT and PET imaging each have particular benefits and limitations when used alone. But by combining these two state-of the-art technologies, physicians can more accurately diagnose, localize, and monitor certain cancers, as well as heart disease and certain brain disorders.
How Is PET/CT Used?
PET/CT imaging helps physicians detect cancer, evaluate the extent of disease, select the most appropriate treatments, determine if the therapy is working, and detect any recurrent tumors.
Before a PET/CT scan, the patient receives an intravenous injection of radioactive glucose. Many cancer cells are highly metabolic and rapidly synthesize the radioactive glucose. Information regarding the location of abnormal levels of radioactive glucose obtained from the whole-body PET/CT scan helps physicians effectively pinpoint the source of cancer and detect whether cancer is isolated to one specific area or has spread to other organs.
From this information physicians can plan an effective treatment strategy. Treatment options include surgery, radiation therapy, systemic therapy, or a combination therapy where one or more of these options are combined.
During the course of treatment, the information from the PET/CT scan allows physicians to monitor the effectiveness of cancer therapies and provides physicians with the opportunity to change the treatment strategy if it is not working, avoiding the cost and discomfort of ineffective therapeutic procedures.
After completing the treatment regimen, a follow-up whole-body PET/CT scan can provide information to assess if the treatment was successful and if areas that were previously abnormally metabolically active have responded. Often, scar tissue at the site of surgical resection or radiation treatment may appear as an abnormality on the CT scan. The PET portion of the PET/CT scan can detect residual disease within the scar tissue and indicate if the treatment was successful or if the tumor has returned.
PET/CT scans provide information to help physicians:
- Locate the site of the cancer
- Determine the size of the tumor
- Differentiate benign from malignant growths
- Discover if the cancer has spread
- Select treatments that are likely to be appropriate
- Monitor the success of therapy
- Detect any recurrent tumors