PET stands for Positron Emission Tomography, which is a clinically proven imaging technique that assists in the diagnosis and management of many diseases, including, most recently, cancer.

PET allows a physician to examine large areas of the body in a single scanning session, producing images of human body functions unobtainable by other imaging techniques. These images capture biochemical processes, such as tissue glucose metabolism, that cannot be revealed by anatomical imaging with conventional X-ray, CT, or MRI.

By uncovering abnormalities that might otherwise go undetected, PET guides physicians to the most appropriate treatment. For example, PET may detect metastatic disease not evident clinically or through routine imaging, resulting in triage of the patient to a more appropriate course of therapy. PET may also demonstrate that abnormalities thought to be malignant, based on CT or MRI, are actually more likely to be benign, based on their level of metabolic activity.

Relevance to Cancer:

PET technology can help physicians answer the critical questions for many cancer patients in one exam:

Summary of Patient Benefits:

How Does PET Compare With Other Imaging Modalities?

Positron Emission Tomography (PET) is a specialized Nuclear Medicine imaging technique that provides physicians with unique diagnostic information that may alter patient management and reduce the total cost of patient care. It produces images of molecular-level physiological function that can be used to measure many vital processes, including glucose metabolism, blood flow, and oxygen utilization. With these images, physicians can identify normal and abnormal states. For oncologic applications, clinical PET in the U.S. is currently limited to the imaging of glucose metabolism, though other applications of PET are likely to be approved in the near future.

This exciting technology extends the capabilities of other advanced imaging modalities. Like MR and CT, for example, it uses proven tomographic computerized image generation techniques to display data as cross-sectional images in any plane. And like other Nuclear Medicine imaging tests, PET images represent the distribution within the body of small amounts of radioactive compounds specially designed to monitor physiologic processes.

But that's where PET's resemblance to other imaging modalities ends.

How is PET Unique?

Current applications

PET is already making critical contributions to more accurate and cost-effective patient management in three primary medical disciplines: oncology; cardiology; and neurology. As researchers use PET to explore the basic physiology underlying disease processes, additional clinical applications are likely to evolve.

Depending on the disease process, PET has unique capabilities that can often help physicians to:

• Diagnose disease before structural changes become detectable with anatomical imaging techniques, potentially improving the prognosis;
• Evaluate suspicious lesions detected on other exams, helping predict whether those lesions are benign or malignant;
• Identify distant, occult metastases that may affect the course of treatment and, therefore, change patient management;
• In some cases, replace multiple diagnostic procedures with a single exam;
• Help predict the potential benefit of planned  surgical procedures, to eliminate those that won't benefit the patient, thus significantly reducing the cost of healthcare delivery and minimizing unnecessary morbidity for the patient;
• Manage patient therapy by monitoring response to a given regimen and providing early feedback on its efficacy, helping to reduce or avoid the cost and potential complications of ineffective treatments or unnecessary hospitalization.