This
procedure is performed at:
Larchmont
Medical Center II, Mt. Laurel
PET is an imaging technology developed during the 1970’s that is rapidly becoming a major diagnostic imaging tool, predominantly for assessments of cancers, neurological conditions, and cardiovascular disease.
PET stands for Positron Emission Tomography, an imaging technique that detects changes in cell metabolism and biochemistry. This distinguishes PET from most conventional medical imaging techniques, such as X-ray, ultrasound, Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) which detect changes in the anatomy or structure of body tissues. By focusing on metabolism, PET is able to identify disturbances inside cells often before the changes are large enough to cause a change in anatomy.
PET has another advantage over CT or MRI alone, in that a PET scan can examine large areas of the body in a single scanning session, producing images of body functions unavailable by other imaging techniques. Increasingly, CT and PET scanners are combined into a single machine, known as PET/CT. With this arrangement, a CT scan is obtained in the same position as the PET scan, allowing more precise matching of areas of abnormal metabolic activity to the corresponding anatomical structures.
Larchmont Imaging now offers the latest PET/CT Technology.
How does PET work?
PET technology detects gamma rays from a tracer injected into your body The most commonly used is fluorodeoxyglucose, or FDG, a glucose (sugar) analog labeled with Fluorine-18. Cancer cells use glucose at a greater rate than normal cells, and will concentrate more of the tracer. These appear as ‘hot spots’ on the PET scan. PET is also useful in diagnosing certain cardiovascular and neurological diseases because it highlights areas with increased, diminished or absent metabolic activity, thereby pinpointing problems.
Applications in Oncology
Most PET imaging today is done to evaluate cancer patients. Prevention and early detection is key in curing cancer. Medicare and other insurers have approved PET reimbursement for several cancer-related problems, including the evaluation of solitary lung nodules for cancer, and the staging of breast cancer, lung cancer, lymphoma, melanoma, colorectal cancer and head and neck malignancies. Other malignancies for which PET is useful include cancers of the esophagus, ovaries, thyroid, cervix, pancreas, and brain.
Benefits and uses of PET in cancer evaluation include:
Early Detection: Because PET images biochemical activity, it can accurately characterize a tumor as benign or malignant, thereby avoiding surgical biopsy when the PET scan is negative. In the case of solitary lung nodules, PET can characterize the nature of nodules larger than 1 cm in size. Because a PET scan images the entire body, it can identify distant metastasis that may alter treatment plans.
Staging of Cancer: PET is extremely sensitive in determining the full extent of disease. Confirmation of metastatic disease allows the physician and patient to more accurately decide how to proceed with treatment. In patients with a diagnosis of cancer, PET is used to evaluate suspicious lesions detected on CT or MRI, helping predict whether those lesions are benign or malignant. Similarly, PET scanning enables doctors to detect cancer in a lymph node before enlargement occurs, allowing for earlier detection and treatment of the cancer.
Checking for Recurrences: PET is currently considered to be the most accurate diagnostic procedure to differentiate tumor recurrences from radiation necrosis or post-surgical changes. This allows for the development of the most appropriate treatment plan for the patient.
Assessing Response to Therapy: Determining the level of tumor response to chemotherapy, surgery and/or radiation therapy is a great challenge. By comparing the level of tumor metabolism on scans taken before and after treatment, PET can confirm a successful response earlier than CT or MRI tests. In fact, PET can often show suppressed or even absent tumor metabolism after only one or two cycles of chemotherapy. Because the PET scan is measuring the 'living chemistry' of the tumor, it can tell the patient with some degree of certainty if a malignancy is still active or not. When PET indicates that a therapy is ineffective, prompt selection of a new therapeutic regimen can then proceed.
Cost Effective: A number of cost analyses have shown that thousands of dollars can be saved without loss of life expectancy when PET is used in the evaluation of cancer patients. PET may result in the earlier diagnosis of cancer. Treatment that is more appropriate may be offered to the patient shown to have less advanced disease. Unnecessary procedures and surgeries may be avoided if the patient is found to have more extensive disease.
Other Applications: PET can evaluate many forms of Neurological Disease including Alzheimer’s disease and other forms of dementia, as well as Parkinson's disease, epileptic seizures and brain tumor. PET is also useful for the evaluation of coronary artery disease.
