***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The purpose of this study was to assess the prognostic value of early 18F-FDG PET using st and ardized uptake value ( SUV ) compared with visual analysis in patients with diffuse large B-cell lymphoma ( DLBCL ) . Methods : Ninety-two patients with newly diagnosed DLBCL underwent 18F-FDG PET prospect ively before and after 2 cycles of chemotherapy ( at midtherapy ) . Maximum SUV ( SUVmax ) and mean SUV ( SUVmean ) normalized to body weight and body surface area , as well as tumor-to-normal ratios , were computed on the most intense uptake areas . The SUVs , tumor-to-normal ratios , and their changes over time were compared with visual analysis for predicting event-free survival ( EFS ) and overall survival , using receiver-operating-characteristic ( ROC ) analysis . Survival curves were estimated with Kaplan – Meier analysis and compared using the log-rank test . Results : With visual analysis , the accuracy of early PET to predict EFS was 65.2 % . The 2-y estimate for EFS was 51 % ( 95 % confidence interval [ CI ] , 34%–68 % ) in the PET-positive group compared with 79 % ( 95 % CI , 68%–90 % ) in the PET-negative group ( P = 0.009 ) . An optimal cutoff value of 65.7 % SUVmax reduction from baseline to midtherapy obtained from ROC analysis yielded an accuracy of 76.1 % to predict EFS . The 2-y estimate for EFS was 21 % ( 95 % CI , 0%–42 % ) in patients with SUVmax reduction ≤ 65.7 % compared with 79 % ( 95 % CI , 69%–88 % ) in those with reduction > 65.7 % ( P < 0.0001 ) . Fourteen patients considered as positive on visual analysis could have been reclassified as good responders . Conclusion : SUV-based assessment of therapeutic response during first-line chemotherapy improves the prognostic value of early 18F-FDG PET compared with visual analysis in DLBCL PET using 18F-FDG has prognostic value when performed at the completion of initial chemotherapy in patients with diffuse large B-cell lymphoma ( DLBCL ) . 18F-FDG PET may also be predictive of outcome when performed during the treatment course of DLBCL , but robust prospect i ve studies and st and ardization of 18F-FDG PET interpretation in this setting are lacking . Methods : In this prospect i ve study , patients with advanced-stage DLBCL were treated with st and ard rituximab , cyclophosphamide , doxorubicin , vincristine , and prednisone chemotherapy , and 18F-FDG PET/CT was performed after cycle 2 or 3 and at the end of therapy . The 18F-FDG PET/CT scans were interpreted according to the International Harmonization Project for Response Criteria in Lymphoma , and the maximum st and ardized uptake value ( SUV ) of the most 18F-FDG – avid lesions was recorded . Results : Fifty patients were enrolled , and all underwent interim 18F-FDG PET/CT . At a median follow-up of 33.9 mo , the positive predictive value ( PPV ) of interim 18F-FDG PET/CT for relapse or progression was 42 % , and the negative predictive value ( NPV ) was 77 % . Interim 18F-FDG PET/CT was significantly associated with event-free survival ( P = 0.017 ) and with progression-free survival ( P = 0.04 ) but not with overall survival ( P = 0.08 ) . End-of-therapy 18F-FDG PET/CT had high PPV and NPV ( 71 % and 80 % , respectively ) and was significantly associated with event-free survival , progression-free survival , and overall survival ( P < 0.001 ) . SUV measurements did not discriminate patients who relapsed or progressed from those who remained in remission . Conclusion : When performed after 2 cycles of immunochemotherapy and interpreted according to International Harmonization Project criteria , early response assessment with PET/CT has a high NPV but low PPV in patients with advanced-stage DLBCL . Prospect i ve trials are required to vali date different criteria for the interpretation of interim 18F-FDG PET/CT and establish the role of interim 18F-FDG PET/CT in the management of patients with DLBCL BACKGROUND The role of rituximab in combination with different CHOP ( cyclophosphamide , doxorubicin , vincristine , and prednisone)-like chemotherapy regimens in young patients with good-prognosis diffuse large-B-cell lymphoma remains to be defined . We aim ed to compare CHOP-like chemotherapy and rituximab with CHOP-like chemotherapy alone in these patients . METHODS 824 patients who were from 18 countries ; aged 18 - 60 years ; and who had no risk factors or one risk factor according to age-adjusted International Prognostic Index ( IPI ) , stage II-IV disease , or stage I disease with bulk were enrolled . These patients were r and omly assigned to six cycles of CHOP-like chemotherapy and rituximab ( n=413 ) or to six cycles of CHOP-like chemotherapy alone ( n=411 ) . Bulky and extranodal sites received additional radiotherapy . The primary endpoint was event-free survival ; secondary endpoints were response , progression under therapy , progression-free survival , overall survival , and frequency of toxic effects . Analyses were done by intention to treat and per protocol . This trial is registered at http://www . clinical trials.gov , NCT 00064116 . FINDINGS After a median follow-up of 34 months ( range 0.03 - 61 ) , patients assigned chemotherapy and rituximab had increased 3-year event-free survival compared with those assigned chemotherapy alone ( 79 % [ 95 % CI 75 - 83 ] vs 59 % [ 54 - 64 ] ; difference between groups 20 % [ 13 - 27 ] , log-rank p<0.0001 ) , and had increased 3-year overall survival ( 93 % [ 90 - 95 ] vs 84 % [ 80 - 88 ] ; difference between groups 9 % [ 3 - 13 ] , log-rank p=0.0001 ) . Event-free survival was affected by treatment group , presence of bulky disease , and age-adjusted IPI : after chemotherapy and rituximab , a favourable subgroup ( ie , IPI=0 , no bulk ) could be defined from a less-favourable subgroup ( ie , IPI=1 or bulk , or both ) . Groups did not differ in the frequency of adverse events . INTERPRETATION Rituximab added to six cycles of CHOP is an effective treatment for young patients with good-prognosis diffuse large-B-cell lymphoma . The definition of two prognostic subgroups allows for a more refined therapeutic approach for these patients The prognostic value of interim positron emission tomography ( PET ) interpreted according to visual criteria is a matter of debate in diffuse large B-cell lymphoma ( DLBCL ) . Maximal st and ardized uptake value reduction ( ΔSUVmax ) may better predict outcome . To compare the prognostic value of both methods , we analyzed PET done at baseline ( PET0 ) and after 2 ( PET2 ) and 4 ( PET4 ) cycles in 85 patients with high-risk DLBCL enrolled on a prospect i ve multicenter trial . All images were central ly review ed and interpreted visually according to the International Harmonization Project criteria and by computing ΔSUVmax between PET0 and PET2 ( ΔSUVmaxPET0 - 2 ) or PET4 ( ΔSUVmaxPET0 - 4 ) . Optimal cutoff to predict progression or death was 66 % for ΔSUVmaxPET0 - 2 and 70 % for ΔSUVmaxPET0 - 4 . Outcomes did not differ significantly whether PET2 and PET4 were visually positive or negative . Inversely , ΔSUVmaxPET0 - 2 analysis ( > 66 % vs ≤ 66 % ) identified patients with significantly different 2-year progression-free survival ( 77 % vs 57 % ; P = .0282 ) and overall survival ( 93 % vs 60 % ; P < .0001 ) . ΔSUVmaxPET0 - 4 analysis ( > 70 % vs ≤ 70 % ) seemed even more predictive for 2-year progression-free survival ( 83 vs 40 % ; P < .0001 ) and overall survival ( 94 % vs 50 % ; P < .0001 ) . ΔSUVmax analysis of sequential interim PET is feasible for high-risk DLBCL and better predicts outcome than visual analysis . The trial was registered at http:// clinical trials.gov as NCT00498043 BACKGROUND Revised response criteria for aggressive lymphomas have been proposed ( Cheson , J Clin Oncol , 2007 ) stressing the role of (18)fluorodeoxyglucose-positron emission tomography ( PET ) in posttreatment evaluation . The value of PET after four cycles compared with the International Workshop Criteria ( IWC ) remains to be established . PATIENTS AND METHODS In all , 103 patients with untreated diffuse large B-cell lymphoma were prospect ively enrolled to evaluate the prognostic impact of PET after two and four cycles . RESULTS Median age was 53 years ( 19 - 79 ) , 68 % male . The International Prognostic Index was low=22 % , low-intermediate=19 % , intermediate-high=33 % and high risk=26 % . Treatment consisted of cyclophosphamide , doxorubicin , vincristine , prednisone ( CHOP ) ( 30 % ) or dose-intensified CHOP ( 70 % ) , with rituximab ( 49 % ) or without ( 51 % ) . Ninety-nine patients were evaluated by PET and IWC at four cycles : 77 ( 78 % ) had a negative PET , while 22 ( 22 % ) remained positive . The 5-year event-free survival ( EFS ) was 36 % for patients with a positive PET versus 80 % with a negative examination , whatever the response [ complete response ( CR ) versus partial response ( PR ) ] according to IWC ( P<0.0001 ) . Positive PET patients had a 5-year EFS of 58 % if in CR/CR unconfirmed by IWC and 0 % if not ( P<0.0001 ) . The same observations could be made in patients treated with and without rituximab . CONCLUSION The integration of PET in treatment evaluation offers a powerful tool to predict outcome PURPOSE (18)F-fluoro-2-dexoy-D-glucose-positron emission tomography (FDG-PET)/computerised tomography ( CT ) has been used for staging and monitoring responses to treatment in patients with diffuse large B cell lymphoma ( DLBCL ) . The sequential interim PET/CT was prospect ively investigated to determine whether it provided additional prognostic information and could be a positive predictable value within patients with the same international prognostic index ( IPI ) after the use of rituximab in DLBCL . METHODS One hundred and sixty-one patients with newly diagnosed DLBCL were enroled ; the assessment of the PET/CT was performed at the time of diagnosis and mid-treatment of rituxibmab , cyclophosphamide , doxorubicin , vincristine and prednisolone ( R-CHOP ) . RESULTS Sixty-seven patients ( 41.6 % ) presented with advanced stage disease and 27 ( 16.8 % ) had bulky lesions . Forty-three patients ( 26.7 % ) continued to have positive metabolic uptakes with a significantly high relapse rate ( 62.8 % ) compared to the patients with a negative interim PET/CT ( 12.1 % ) ( P<0.01 ) . After a median follow-up of 30.8months , the positivity of interim PET/CT was found to be a prognostic factor for both overall survival ( OS ) and progression-free survival ( PFS ) , with a hazard ratio of 4.07 ( 2.62 - 6.32 ) and 5.46 ( 3.49 - 8.52 ) , respectively . In the low-risk IPI group , the 3-year OS and PFS rates were significantly different in the patients with positive ( 53.3 % and 52.5 % ) and negative ( 93.8 % and 88.3 % ) interim PET/CT , respectively ( P<0.01 ) . These significant prognostic differences of interim PET/CT responses were consistent with the results of the patients with high-risk IPI group ( P<0.01 ) . CONCLUSIONS Interim PET/CT scanning had a significant predictive value for disease progression and survival of DLBCL in post-rituximab treatment ; it might be the single most important determinant of clinical outcome in patients with the same IPI risk 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 
    Output:
    
Consistent evidence favoring interim (18)F-FDG PET-based treatment assessment should be considered in the management of patients with DLBCL