End-therapy positron emission tomography for treatment response assessment in follicular lymphoma: a systematic review and meta-analysis.

Abstract

Use of 2[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in postchemotherapy response assessment in follicular lymphoma is still a controversial issue. Here, we conducted the first systematic review and meta-analysis to determine the predictive value of FDG-PET in predicting outcome after chemotherapy of follicular lymphoma. Comprehensive literature search in Ovid-MEDLINE and EMBASE databases was performed to identify studies which evaluate predictive value of end-therapy PET and/or computed tomography (CT) in patients with follicular lymphoma. To quantitatively compare the predictive value of PET and CT, pooled hazard ratios (HRs) comparing progression-free survival (PFS) between patients with positive and negative results were adopted as the primary indicators for meta-analysis. To explore the efficiency in determining complete remission (CR), pooled CR rates of PET- and CT-based response criteria were calculated. Pooling of these parameters was based on the random-effects model. Review of 285 candidate articles identified eight eligible articles with a total of 577 patients for qualitative review and meta-analysis. The pooled HRs of end-therapy PET and CT were 5.1 [95% confidence interval (CI), 3.7-7.2] and 2.6 (95% CI, 1.2-5.8), respectively, which implies that PET is more predictive of PFS after chemotherapy than CT. The pooled CR rates of PET- and CT-based response criteria were 75% (95% CI, 70-79%) and 63% (95% CI, 53-73%), respectively, which implies that PET is more efficient in distinguishing CR (without residual disease) from other states with residual disease. In addition, qualitative systematic review indicates the same findings. Consistent evidence favoring PET-based treatment assessment should be considered in the management of patients with follicular lymphoma.