Positron Emission Tomography With 2-[18F]-Fluoro-2-Deoxy-D-Glucose For Initial Staging Of Hodgkin Lymphoma: A Single Center Experience In Brazil

BACKGROUND 2-[18F]-Fluoro-2-Deoxy-D-Glucose (FDG-PET) is a well established functional imaging modality for the initial staging of Hodgkin lymphoma (HL) in patients from Western Europe and North America. The reliability of FDG-PET in populations of different ethnic groups is unclear, as all investigations published to date have come from developed countries. PURPOSE The aim of the present study was to investigate the effectiveness of FDG-PET in the initial staging of HL patients in a Brazilian population. METHODS Eighty-two patients with newly diagnosed HL were prospectively included in the study. All patients were staged with both conventional clinical staging (CCS) methods, including computed tomography (CT) and whole-body FDG-PET methods. A standard of reference for the nodal regions and the extranodal organs was determined using all available information, including the CCS methods, FDG-PET, the diagnostic histology and the follow-up examinations. The results of the CCS were then compared to the FDG-PET results. RESULTS The sensitivity of FDG-PET was higher for nodal staging than that of CT (87.8% vs. 61.6%, respectively). FDG-PET was also more sensitive than CT in regard to evaluating the extranodal organs for lymphomatous involvement (96.2% vs. 40.0%, respectively). FDG-PET detected all 16 patients who were characterized by a positive bone marrow biopsy and identified an additional 4 patients with bone marrow disease. The incorporation of FDG-PET coupled with CCS in the staging procedure upstaged 20% (17/82) of the patients and downstaged 11% (9/82) of the patients. As a result of these changes in staging, 15% (13/82) of the patients would have received a different therapeutic regimen. CONCLUSIONS The FDG-PET method is superior to CT for the detection of nodal and extra-nodal HL. The observation that the FDG-PET method upstaged the disease was the most common result (20% of patients) brought about by the addition of PET to the staging algorithm, even in a population of patients with a high incidence of advanced disease. However, changes in stages based on FDG-PET results should be confirmed by biopsy.