PET CT is particularly effective in identifying whether cancer is present, if it has spread, if it is responding to treatment, and if a person is cancer-free after treatment. Cancers for which PET CT is considered particularly effective include lung, head and neck, colorectal, esophageal, lymphoma, melanoma and breast, as well as a variety of other tumors. Staging and restaging of oncology patients may help direct oncologists toward the most effective treatment and avoid unnecessary therapies.

Man looking at a scan
PET is a non-invasive, nuclear-medicine procedure that, by visualizing the metabolic processes occurring in the body, is able to detect certain diseases before other imaging modalities can.

Early Detection

Because PET CT images biochemical activity, it can accurately characterize some tumors as benign or malignant, thereby avoiding surgical biopsy when the PET CT scan is negative. Conversely, because a PET CT scan images the entire body, confirmation of distant metastases can alter treatment plans, in certain cases, from surgical intervention to chemotherapy.

Staging of Cancer

PET CT is extremely sensitive in determining the full extent of disease, especially in lymphoma, malignant melanoma, breast, lung and colon cancers. Confirmation of the presence or absence of metastatic disease allows the physician to more effectively decide how to proceed with the patient's management.

Checking for Recurrences

PET CT is currently considered to be the most accurate diagnostic procedure to differentiate tumor recurrences from radiation necrosis or post-surgical changes in many types of cancer. Such an approach allows for the development of a more rational treatment plan for the patient.

Assessing the Effectiveness of Chemotherapy

The level of tumor metabolism is compared on PET CT scans taken before and after a chemotherapy cycle. PET CT can provide important information about the effectiveness of a chemotherapy treatment plan and whether a different therapeutic option might be considered.

Neurological Disease

PET CT's ability to measure metabolism has significant implications in localizing the site or origin of epilepsy, because it can vividly illustrate areas where brain activity differs from the norm. PET CT can also be used to differentiate Alzheimer's disease from other causes of dementia in cases where the clinical picture is atypical. This can be achieved either by imaging brain metabolism or by directly visualizing amyloid plaques in the brain in patients with Alzheimer’s disease.

Cardiovascular Disease

By measuring both perfusion and metabolic activity within the heart, PET CT scans can pinpoint areas of decreased blood flow, such as that caused by artery blockages, and can differentiate muscle damage from living muscle. This information is particularly important in patients who have had previous myocardial infarction and who are being considered for a revascularization procedure.