Imaging , Diagnosis , Prognosis End-Therapy Positron Emission Tomography for Treatment Response Assessment in Follicular Lymphoma : ASystematic Review and Meta-analysis

Purpose: Use of 2[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. Experimental Design: 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 andCT, 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 PETand CT-based response criteria were calculated. Pooling of these parameters was based on the random-effects model. Results: Review of 285 candidate articles identified eight eligible articles with a total of 577 patients for qualitative review andmeta-analysis. The pooledHRs of end-therapy PET andCTwere 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 PETand 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) fromother states with residual disease. In addition, qualitative systematic review indicates the same findings. Conclusions:Consistent evidence favoring PET-based treatment assessment should be considered in the management of patients with follicular lymphoma. Clin Cancer Res; 19(23); 6566–77. 2013 AACR. Introduction Follicular lymphoma, a common histologic type of nonHodgkin lymphoma, is indolent with variable clinical behavior. It is regarded as an incurable disease, because follicular lymphoma almost inevitably relapses even after achieving good response to chemotherapy and patients with residual disease or early relapse after therapy show worse prognosis. Recently, Bachy E. et al reported that patients with a better response to first-line chemotherapy for follicular lymphoma (especially, complete response) show improved survival (1). Therefore, accurate response assessment at the end of first-line chemotherapy is very important topredict outcomeof eachpatient and to identify patients with residual disease who may benefit from additional treatment. The use of 2[F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) or FDG-PET/computed tomography (FDG-PET and FDG-PET/CT are hereafter referred to as PET) for postchemotherapy response assessment has been the standard of care in the management of Hodgkin lymphomas and diffuse large B-cell lymphomas (2), based on the strong evidence that negative results of an end-therapy PET scan indicate a better outcome and are highly predictive of progression-free survival (PFS) and overall survival (OS; ref. 3, 4). PET is particularly helpful to differentiate true residual disease from a treated fibrotic lesionwhen there is residualmass onCT after chemotherapy for Hodgkin lymphoma or diffuse large B-cell lymphomas Authors' Affiliations: Center for Evaluation Value and Risk in Health, The Institute for Clinical Research and Health Policy Studies, Tufts Medical Center; Departments of Imaging and Medical Oncology, Dana–Farber Cancer Institute; Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; and Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea Note: Supplementary data for this article are available at Clinical Cancer Research Online (http://clincancerres.aacrjournals.org/). Corresponding Author: Kyung Won Kim, Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Pungnab-2-dong, Songpa-gu, Seoul 138-736, Korea. Phone: 82-2-3010-4352; Fax: 82-2-476-4719; E-mail: medimash@gmail.com doi: 10.1158/1078-0432.CCR-13-1511 2013 American Association for Cancer Research. Clinical Cancer Research Clin Cancer Res; 19(23) December 1, 2013 6566 on July 25, 2017. © 2013 American Association for Cancer Research. clincancerres.aacrjournals.org Downloaded from Published OnlineFirst September 19, 2013; DOI: 10.1158/1078-0432.CCR-13-1511