Clinical Indications for PET

ONCOLOGY
Glucose metabolic Positron Emission Imaging studies of the whole body are used to evaluate malignant tumors. Tumor cells have been found to take up F-18-FDG more avidly than normal cells and metabolic images are used to demonstrate tumor extent. Positron Emission Imaging has been most extensively utilized in evaluating lung cancer, colon cancer, melanoma, and lymphoma, and PET has been found to be more accurate than CT (85-95% vs. 60-70% accuracy) for demonstration of tumor. Valuable results have also been obtained assessing breast cancer, head and neck tumors, sarcoma of soft tissue and bones, and ovarian cancer. Positron Emission Imaging is especially valuable for:

1. Tumor staging at initial diagnosis.
2. Diagnosis of suspected tumor recurrence.
3. Evaluation of response to therapy.

Essentially all cancers and indications are covered for Medicare patients. Click here for html and pdf versions of the table showing coverage for Medicare patients.

In general, application of FDG imaging in the diagnosis of various cancers reduces the need for exploratory surgeries and surgical resections in patients with extensive metastatic disease. FDG imaging aids physicians in determining the most appropriate treatment course and lowers overall health care costs by eliminating unnecessary resections and their associated disability and rehabilitative costs.

NEUROLOGY
The most commonly performed Positron Emission Imaging study of the brain is a study of glucose metabolism using the radiopharmaceutical F-18 Flurodeoxyglucose (FDG).

Indications include:

1. Differentiation of recurrent tumor from post-therapy changes.
2. Localization of seizure focus in partial complex epilepsy.
3. Differential diagnosis of Alzheimer's Disease and fronto-temporal dementia.

Eliminates need for other neurosurgical procedures that would otherwise be necessary to determine tumor recurrence of foci localization.

CARDIOLOGY
An important application of Positron Emission Imaging in cardiology is evaluation of myocardial viability by metabolic imaging with F-18-FDG. In most patients with coronary artery disease, viability can be evaluated by conventional means. However, in patients with significant left ventricular dysfunction (e.g., patients in heart failure) it is frequently not possible to determine whether heart muscle is alive or infarcted by conventional means. In those cases, Positron Emission Imaging is needed to determine which patients can potentially benefit from revascularization procedures.
In both acute and chronic cardiac disease, evaluates clinical necessity for performing diagnostic and therapeutic procedures such as angiography, angioplasty, bypass surgery and cardiac transplantation. Most accurate measurement in predicting recovery of left ventricular function after intervention.