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 accuratedefinition of extent of disease (stage). Computerised tomography is widelyused in staging but cannot reliably evaluate normal sized lymph nodes and someextranodal sites, e.g., liver, spleen and bone marrow.2-Fluorine-18-fluoro-2-deoxy-D glucose (FDG) has been shown to concentratepreferentially in lymphoma sites (whether in nodal or extranodal tissue) andtherefore may have a useful role in staging patients with HD. This studycompares concurrent computerized tomography (CT) and FDG positron emissiontomography (PET) in the staging of Hodgkin's disease and assesses thefrequency of stage migration and possible changes in therapy related to theuse of PET scanning.Patients and methods:This was a single centre retrospective studyof 44 patients with Hodgkin's disease who underwent both staging CT and PETprior 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 demonstratedin forty-four patients by FDG–PET compared with eighty-four by CT. Asa result, 18 (40.9%) patients were upstaged, nine of these byFDG-uptake in splenic or extranodal sites not visualised on CT. Only threepatients were downstaged by PET results. Eleven patients (25%) hadtreatment modified by PET scan findings.Conclusions:Significantly more sites of disease were identifiedby PET than CT resulting in stage changes and a modification of therapy in25% of patients. This has important implications not only for currentpatient management but also for the design of future clinical trials.