Research On The Midterm Efficacy And Prognosis Of Patients With Diffuse Large B-cell Lymphoma By Different Evaluation Methods In Interim PET/CT

BackgroundLymphomas are malignant tumors that originate in lymph-nodes and/or extra-nodal lymphoid tissues,and they are usually divided into different subtypes.Diffuse large B-cell lymphoma(DLBCL)is the most common non-Hodgkin lymphoma(NHL)in the world,accounting for 25%-35%of NHLs.DLBCL is a highly heterogeneous sand aggressive malignant tumor.DLBCL is biologically divided into germinal center B-cell-like(GCB)and activated B-cell-like(ABC)subtypes.These two DLBCL subtypes which from different cell origins have different carcinogenic activation mechanisms.And the latter is more aggressive with a relatively poor prognosis.Rituximab,cyclophosphamide,doxorubicin,vincristine and prednisone(R-CHOP)have been established as standard first-line regimen for patients with DLBCL.Although more than 50%of DLBCL patients can achieve lasting remission,as many as one-third of patients still eventually develop a relapsed or refractory(R/R)disease.Therefore,timely systemic evaluation of DLBCL patients in the middle of therapy is very important for the prognosis and the development of follow-up treatment choices.Positron emission tomography and computed tomography(PET/CT)can simultaneously provide accurate information about the anatomy and function of target organs.At present,Fluoro-18-Fluorodeoxyglucose(18F-FDG)PET/CT,as a common imaging examination for the diagnosis of DLBCL,has been widely used in diagnosis,staging and re-staging,efficacy monitoring and prognostic evaluation.In PET/CT,the most common used evaluation criteria,include the International Harmonization Project(IHP)criterion,the Deauville 5-point scale(5-PS)criterion,and the SUVmax reduction(ΔSUVmax)criterion.Therefore,this research explored the value of three image analysis methods of IHP criterion,5-PS criterion and ΔSUVmax criterion in 18F-FDG PET/CT in assessing the midterm efficacy and prognosis of patients with DLBCL.Materials and MethodsA total of 141 patients with DLBCL admitted to the First Affiliated Hospital of Zhengzhou University from June 2011 to May 2019 were collected.Collect clinical information of all patients,including age,gender,Ann Arbor staging,International prognostic index(IPI)score or age adjusted IPI(age adjusted IPI,aaIPI,applicable to age<60 years),pathological classification,β2-microglobulin,LDH level,B symptom,performance status refers to the Eastern Cooperative Oncology Group(ECOG),extra-nodal involvement,Ki67 level and chemotherapy regimens.After 3-4 cycles of chemotherapy,all patients were divided into complete response(CR),partial response(PR),stable disease(SD),relapse disease or progressive disease(PD)based on the results of clinical examinations and the revised standards of the International Working Group(IWG).Record progression-free survival(PFS)and overall survival(OS)as survival analysis indicators.SPSS 25.0 statistical software was used to process the data,and the receiver operating characteristic(ROC)curve was used to obtain a model of ΔSUVmax criterion in judging midterm efficacy and survival results.Kappa test,McNemar’s test,Cochran’s Q test and pairwise comparisons were performed on the IHP criterion,5-PS criterion and ΔSUVmax criterion in evaluating midterm efficacy.Kaplan-Meier survival analysis was used to calculate the survival curve.Through univariate and multivariate Cox regression analysis the differences between these three criteria in survival analysis and other factors that may affect the prognosis of DLBCL patients.Except for the test level a of univariate Cox regression analysis which is 0.15,the other test level a is 0.05.ResultsBy the cut-off time of follow-up,among 141 patients,there were 109 CRs,23 PRs,4 SDs,and 5 PDs.We defined RD to be non-CR that included PR,SD and PD.According to the IHP criterion,63 patients were in the positive group and 78 patients were in the negative group after treatment.Kappa test showed that the results were consistent with that of the CR/RD group,but the consistency was medium.McNemar’s test showed that the positive rate of CR/RD group was 77.3%,and the positive rate of IHP criterion was 44.7%.The difference between the CR/RD group and the IHP criterion was statistically significant(P<0.05).According to the 5-PS criterion,97 patients were in negative group and 44 patients were in positive group after treatment.The results of Kappa test showed that the results of 5-PS criterion and CR/RD group were consistent and had strong consistency.McNemar’s test showed a positive rate of 31.2%,which was statistically different from the CR/RD group(P<0.05).ROC curve was drawn according to the ΔSUVmax criterion.The optimal cutoff value was calculated to be 81.54%.ΔSUVmax%≤81.54%was defined as positive,and ΔSUVmax%>81.54%was defined as negative(AUC=0.925).After treatment,41 patients were in the positive group and 100 patients were in the negative group.The results of Kappa test showed that the results of ΔSUVmax criterion and CR/RD group were consistent and had strong consistency.McNemar’s test showed a positive rate of 29.1%,which was statistically different from the CR/RD group(P<0.05).Cochran’s Q test was performed on the three criteria,it indicated that the three methods had significant differences in judging the midterm efficacy of patients with DLBCL.Pairwise comparisons showed that there were statistically differences between IHP and 5-PS criteria and between IHP and ΔSUVmax criteria(adjusted P=0.000),but there was no statistical difference between 5-PS and ΔSUVmax criteria(adjusted P=1.000).A total of 16 patients died during the follow-up period,and neither OS nor PFS reached the median survival time.The average OS was 88.964 months,and the average PFS was 83.385 months.For patients who are classified as negative and positive by IHP criterion and 5-PS criterion,the differences in OS and PFS between the groups were not statistically significant.For the ΔSUVmax criterion,the ROC curve was used to obtain the best cutoff value of 75.635%.The differences in OS and PFS between the two groups were statistically significant.Univariate Cox regression analysis results show that age,gender,Ann-Arbor stage,IPI/aaIPI,β2-microglobulin,Ki67 level,IHP,5-PS and Δ SUVmax criteria were meaningful factors.The results of multivariate Cox regression analysis showed that age,gender,Ki67 level and ΔSUVmax criterion were independent risk factors in OS and PFS for DLBCL patients.Conclusion1.Three different 18F-FDG PET/CT evaluation criteria of IHP criterion,5-PS criterion and ΔSUVmax criterion all have good clinical value in evaluating the midterm efficacy and prognosis of DLBCL patients.2.The ΔSUVmax criterion was better,with the highest accuracy rate,the lowest positive predictive value and misdiagnosis rate.3.The ΔSUVmax criterion was an indicator for judging the progress or recurrence of DLBCL patients in the midterm evaluation.The recommended optimal cut-off value of ΔSUVmax was 81.54%.