Systematic Review on the Additional Value of 18F-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography in Staging Follicular Lymphoma.

Abstract

This study aimed to systematically review the additional value of F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) to computed tomography (CT) for staging newly diagnosed follicular lymphoma in terms of Ann Arbor staging and Follicular Lymphoma International Prognostic Index (FLIPI) risk stratification. The PubMed/MEDLINE database was searched for relevant original studies. Included studies were methodologically assessed. Data on the frequency of FDG-PET-induced changes in Ann Arbor stage and FLIPI score relative to CT were (meta-)analyzed when possible. Seven studies with a total of 349 patients were included. Overall, studies were of very poor methodological quality, with lack of histological verification of additionally detected lesions at FDG-PET in almost all cases and only 1 study that exclusively included patients with CT-based limited nonbulky stage I to II disease. The proportion of patients who were upstaged by FDG-PET compared with CT ranged from 0.0% to 45.2%, with a pooled summary proportion of 18.7% (95% confidence interval, 10.8%-30.4%). The single study that only included patients with CT-based limited nonbulky stage I to II disease reported FDG-PET-induced upstaging in 40.5% (95% confidence interval, 27.0%-55.5%) of cases. No study reported data on the influence of FDG-PET on FLIPI risk stratification. Although upstaging by FDG-PET compared with CT occurs in a considerable proportion of patients, the available studies on this topic have numerous methodological errors. Data on FDG-PET-induced FLIPI risk stratification changes relative to CT are lacking. Future well-designed studies are needed before FDG-PET can be recommended for routine pretreatment staging of follicular lymphoma.