Prognostic Value Of Baseline PET/CT Metabolic Parameters Combined With Clinicopathological Features In Assessing Diffuse Large B-cell Lymphoma

Objective:To investigate the evaluation value of baseline ¹⁸F-FDG PET/C T multi-metabolic parameters combined with clinicopathological features on the prognosis of diffuse large B-cell lymphoma（DLBCL）.Methods:From January 2016 to July 2022,86 patients with histologically proven DLBCL were retrospectively collected in this study in Lanzhou University Second Hospital,and all patients underwent ¹⁸F-FDG PET/CT examination before treatment.Baseline ¹⁸F-FDG PET/CT multi-metabolic parameters were measured from all DLBCL patients,including maximum standardized uptake value（SUVmax）,tumor metabolic volume（MTV）,total glycolysis（TLG）,and lesion/liver SUVmax ratio（LLR）.Meanwhile,clinicopathological characteristics at the time of initial diagnosis were also recorded,general information including age,sex,physical status（ECOG）,serum biochemical indices including pre-treatment lactate dehydrogenase（LDH）,pre-treatmentβ2-microglobulin（β2-MG）and pre-treatment hemoglobin levels,path-ological molecular characteristics including myeloblastomatosis oncogene（MYC）,B-cell leukemia/lymphoma factor-2 gene（BCL2）,B-cell leukemia/lymphom-a factor-6gene（BCL6）protein expression,MYC/BCL2 protein double expression,MYC/BCL6protein double expression,germinal center/non-germinal center origin（GCB/non-GCB）,cell proliferation nuclear antigen（Ki-67）,and other indices including maximum tumor diameter and Ann Arbor staging.According to clinical indicators,the International Prognostic Index（IPI）and modified International Prognostic Index（NCCNIPI）scoring were conducted for each patient in this study,respectively.Patients were divided into good prognosis and poor prognosis groups based on their survival status at the end of follow-up,using disease recurrence,progression,and death as positive events,while receiver operating characteristic curves（ROC）were drawn to determine the optimal judgment threshold for assessing the prognosis of DLBCL patients by each metabolic parameter at baseline ¹⁸F-FDG PET/CT.Progression-free survival（PFS）and overall survival（OS）of DLBCL patients were determined according to the survival status of patients at the follow-up deadline,and independent prognostic factors affecting patients’PFS and OS were screened using one-way Kaplan-Meier survival analysis and multi-factor Cox regression analysis,and patients were further assigned to risk stratification to compare the prognostic differences of patients between different risk groups.Results:Of the 86 patients with DLBCL,49 were male and 37 were female with a mean age of 57.27±12.83 years.The total follow-up time was 7.00-69.00 months,with a mean follow-up time of 32.20 months and a median follow-up time of 30.00months.At the follow-up deadline,22 of the 86 patients had progressed or recurred,13 had died,and 51 had no progression or recurrence.The ¹⁸F-FDG PET/CT metabolic parameters of SUVmax,MTV,TLG,and LLR were 20.45（14.97,30.33）,132.13（28.39,293.79）cm³,999.99（344.17,3761.55）g,and 8.31（5.54,9.78）,respectively,and the results of ROC analysis showed MTV,TLG,and LLR can provide a valid evaluation of the prognosis of DLBCL patients,and the best judgment thresholds for assessing prognosis were 130.780 cm³,901.470g,and 8.009,respectively.Univariate analysis showed that MTV,TLG,LLR,NCCNIPI score,LDH,β2-MG,maximal tumor diameter,MYC,BCL2,MYC/BCL2,MYC/BCL6 were prognostic influences on PFS in DLBCL patients（all P<0.05）;while MTV,TLG,LLR,NCCNIPI score,LDH,maximal tumor diameter,MYC,BCL2,BCL6,MYC/BCL2,MYC/BCL6 were prognostic influencing factors for OS in DLBCL patients（all P<0.05）.Multifactorial Cox regression analysis showed that NCCNIPI,MYC,and LLR were independent risk factors for PFS in patients with DLBCL（all P<0.05）,while none of the above clinicopathological features and ¹⁸F-FDG PET/CT metabolic parameters were independent risk factors for OS in patients with DLBCL（all P>0.05）.Patients were divided into high-risk,intermediate-risk,and low-risk groups according to the results of Cox regression analysis,and the results of survival analysis showed a statistically significant difference in prognosis among patients in different groups（P<0.05）.Conclusion:1.In this study,the baseline ¹⁸F-FDG PET/CT metabolic parameters MTV,TLG,and LLR of DLBCL patients could provide a valid assessment of the prognosis of DLBCL patients,among which LLR was the strongest.2.Among the clinicopathological factors,only NCCNIPI score and MYC were independent prognostic factors for patients’PFS,and all clinicopathological factors were not independent predictors of patients’OS;among the baseline ¹⁸F-FDG PET/CT metabolic parameters,only LLR was an independent risk factor for patients’PFS,SUVmax,MTV,and TLG were not independent risk factors for patients’OS.3.¹⁸F-FDG PET/CT multimetallic parameters combined with clinicopathological features can help to effectively assess the prognosis of DLBCL patients in different risk strata before treatment.