Prognostic Value Of Baseline ¹⁸F-FDG PET/CT Imaging In Patients With Diffuse Large B-cell Lymphoma

Objective:The purpose of this study is to explore the prognostic value of baseline ¹⁸F-FDG PET/CT metabolic parameters in diffuse large B-cell lymphoma（DLBCL）,so as to better guide clinical decision-making.Methods:A retrospective analysis was made on 74 cases of DLBCL diagnosed by pathology in our hospital from November 2019 to November 2021.All these patients underwent baseline ¹⁸F-FDG PET/CT scan before chemotherapy,and the chemotherapy regimen was R-CHOP.Clinical data of the patients were collected completely,including gender,age,Ann Arbor staging,IPI score,ECOG behavioral status score,presence or absence of B symptoms,number of extranodal organs involved,presence or absence of giant mass,pathological subtype,Ki67 level,LDH level,β2 microglobulin level and baseline ¹⁸F-FDG PET/CT metabolic parameters including SUVmax,SUVpeak,MTV and TLG.The end point of this study was progression-free survival（PFS）.Chi-square test was used to compare the baseline metabolic parameters with clinical features,Spearman was used to analyze the rank correlation,and Kaplan-Meier method,Log-rank test and COX multivariate regression were used to analyze the prognostic evaluation value of each index.Results:A total of 74 patients with DLBCL were included in this study,including 47males（64%）and 27 females（36%）,with a male-female ratio of 1.7:1.The age ranged from 28 to 87,with an average age of 59.41±11.731 and a median age of 61.Through ROC curve,it is found that MTV and TLG can better diagnose the recurrence and progress of DLBCL,and they are grouped with truncation values of341.58 and 2019.40,while SUVmax and SUVpeak are grouped with median values of 18.77 and 14.49.Chi-square test showed that the levels of SUVmax and SUVpeak were different only in IPI score,while the levels of MTV and TLG were different in Ann Arbor stage,IPI score,ECOG behavior status score,B symptoms,number of organs involved outside the node,presence or absence of giant,pathological subtype and LDH level.The results of Spearman grade correlation analysis showed that MTV and TLG were related to the patient’s Ann Arbor stage,IPI score,ECOG behavior status score,the number of extranodal organs involved,the presence or absence of B symptoms,the presence or absence of large masses and LDH level（P<0.05）.However,SUVmax and SUVpeak were not correlated with sex,age,Ann Arbor stage,IPI score,ECOG behavioral status score,presence or absence of B symptoms,number of extra-nodal organs involved,presence or absence of giant,pathological subtype,Ki67 level,LDH level andβ2 microglobulin level（P>0.05）.Univariate analysis showed that among the clinical factors,age,Ann Arbor stage,IPI score,ECOG behavioral status score,presence or absence of B symptoms,number of extranodal organs involved and LDH level were the influencing factors of PFS（P<0.05）.Among the baseline metabolic parameters of PET/CT,only MTV and TLG were the influencing factors of PFS（P<0.05）,and other factors were not related to PFS.Multivariate analysis showed that MTV and ECOG behavioral status scores were independent prognostic factors for PFS in patients with DLBCL（P<0.05）.Conclusion:Among the metabolic parameters of baseline ¹⁸F-FDG PET/CT,MTV is an independent risk factor for PFS of patients with DLBCL,which has certain reference value for prognosis judgment of patients with DLBCL.High MTV frequently indicates a bad prognosis.