Lymphoma is classified as either Hodgkin's or non-Hodgkin's lymphoma. In 2002, there will be about 7,000 new cases of Hodgkin's disease and about 53,900 cases of NHL diagnosed, according to the American Cancer Society. The malignant lymphomas are the most common malignant tumors of adults between the ages of 20-40 years. The treatment of lymphoma has been one of the true oncologic success stories of the last 20-30 years. Continued improvements in chemotherapy and radiotherapy have resulted in better survival rates. Proper staging of the location and extent of the tumor is the first step in appropriate treatment. Moreover, once treated, patients are often re-staged to determine the effectiveness of the treatment.
		PET is the most accurate imaging technique available for staging and re-staging patients with lymphoma. In the initial staging, PET provides a baseline for subsequent evaluation of therapy. Whole Body PET may be particularly useful in detecting extra nodal sites of disease such as bone marrow, liver and spleen. PET can help doctors selecte a site for biopsy when the first suspected site is not easily accessible. Since lymphoma may appear at several sites or be widespread, Whole Body PET scanning is excellent to check for recurrence and to guide therapy effectiveness. PET may be useful following therapy to evaluate patients with persistently enlarged lymph nodes for residual tumor. PET may also identify patients who are more likely to achieve remission and less likely to relapse by showing a decrease in the metabolic activity of abnormal lymph nodes during chemotherapy.