title: Limited role of interim PET/CT in patients with diffuse large B-cell lymphoma treated with R-CHOP.
abstract: Positron emission tomography (PET) has been found useful in monitoring response to treatment of malignant lymphoma. We investigated the ability of interim PET to monitor response to standard dose R-CHOP chemotherapy in chemotherapy-naïve patients with diffuse large B-cell lymphoma (DLBCL). Between March 2004 and April 2009, 155 DLBCL patients treated with R-CHOP and available for interim and post-treatment PET/CT were identified and included in this analysis. Response, progression-free survival (PFS), and overall survival (OS) were compared between interim PET/CT-negative and positive group, and among three patient groups which were categorized based on their interim and post-treatment PET/CT: those with early metabolic complete response (mCR), delayed mCR, and never mCR. Interim PET/CT-negative patients (n=100) showed superior CR rates to interim PET/CT-positive patients (n=55; 93% vs 62%, P<0.001). However, there was no difference in PFS (P=0.07) and OS (P=0.24) between interim PET/CT-negative and positive group. We categorized patients into three groups, with 100 (64%) in the early mCR group, 35 (23%) in the delayed mCR group, and 20 (13%) in the never mCR group. Early mCR and delayed mCR group did not differ significantly in PFS (P=0.84) or OS (P=0.20). However, the survival outcome in the never mCR group was significantly inferior to the combined early and delayed mCR group. The result from this study suggests that interim PET/CT might be an inappropriate tool for designing risk-adaptive therapy in chemotherapy-naïve DLBCL patients treated with R-CHOP. Prospective trials should be performed to clearly determine the role of interim PET/CT.
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Souel, South Korea.
authors.forename: Changhoon
authors.initials: C
authors.lastname: Yoo
authors.forename: Dae Ho
authors.initials: DH
authors.lastname: Lee
authors.forename: Jeong Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Jungmin
authors.initials: J
authors.lastname: Jo
authors.forename: Dok Hyun
authors.initials: DH
authors.lastname: Yoon
authors.forename: Byeong Seok
authors.initials: BS
authors.lastname: Sohn
authors.forename: Sang-We
authors.initials: SW
authors.lastname: Kim
authors.forename: Jung-Shin
authors.initials: JS
authors.lastname: Lee
authors.forename: Cheolwon
authors.initials: C
authors.lastname: Suh
mesh_terms: D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D003520:Cyclophosphamide / Q000627:therapeutic use; D016208:Databases, Factual; D018572:Disease-Free Survival; D004317:Doxorubicin / Q000627:therapeutic use; D005260:Female; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011241:Prednisone / Q000627:therapeutic use; D012189:Retrospective Studies; D000069283:Rituximab; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014750:Vincristine / Q000627:therapeutic use
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D000069283:Rituximab; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone