2-Fluorine-18-fluoro-2-deoxy-D glucose positron emission tomography in the pretreatment staging of Hodgkin's disease: influence on patient management in a single institution.

PURPOSE: Optimum therapy for patients with Hodgkin's disease (HD) is determined by a number of prognostic factors, one of which is an accurate definition of extent of disease (stage). Computerised tomography is widely used in staging but cannot reliably evaluate normal sized lymph nodes and some extranodal sites, e.g., liver, spleen and bone marrow. 2-Fluorine-18-fluoro-2-deoxy-D glucose (FDG) has been shown to concentrate preferentially in lymphoma sites (whether in nodal or extranodal tissue) and therefore may have a useful role in staging patients with HD. This study compares concurrent computerized tomography (CT) and FDG positron emission tomography (PET) in the staging of Hodgkin's disease and assesses the frequency of stage migration and possible changes in therapy related to the use of PET scanning. PATIENTS AND METHODS: This was a single centre retrospective study of 44 patients with Hodgkin's disease who underwent both staging CT and PET prior to treatment between September 1993 and August 1998 at St. Thomas' Hospital. The number and sites of disease were assessed for each patient, documenting any stage and therapy modification prompted by PET findings.
RESULTS: One hundred fifty-nine sites of disease were demonstrated in forty-four patients by FDG-PET compared with eighty-four by CT. As a result, 18 (40.9%) patients were upstaged, nine of these by FDG-uptake in splenic or extranodal sites not visualised on CT. Only three patients were downstaged by PET results. Eleven patients (25%) had treatment modified by PET scan findings.
CONCLUSIONS: Significantly more sites of disease were identified by PET than CT resulting in stage changes and a modification of therapy in 25% of patients. This has important implications not only for current patient management but also for the design of future clinical trials.