[Prognostic Value of Baseline ¹⁸F-FDG PET/CT Combined with Clinicopathological Characteristics in Diffuse Large...

To investigate the prognostic value of ¹⁸ F-deoxyglucose (FDG) PET/CT metabolic parameters combined with clinicopathological features for newly diagnosed diffuse large B-cell lymphoma (DLBCL) before treatment, and analyze the relationship between tumor metabolic volume (MTV), total lesion glycolysis (TLG) and clinicopathological features.

The clinical data of 120 patients with pathologically confirmed DLBCL were retrospectively analyzed and ¹⁸F-FDG PET/CT was performed 1 week before treatment. The metabolic parameters including SUVmax, SUVmean, tumor-to-blood standardized uptake value ratio (TBR), tumor-to-liver standardized uptake value ratio (TLR) were obtained. MTV and TLG of the lesions were obtained with 41% of SUVmax as the threshold, and the correlation of MTV and TLG with clinicopathological features were analyzed. Progression-free survival (PFS) was calculated by follow-up for 6-153 months. Receiver operating characteristic (ROC) curve, chi-square test, Kaplan-Meier test, log-rank test and Cox proportional hazards model were used to analyze the date.

The optimum cut-off values of the SUVmax, MTV, TLG, TBR and TLR for predicting tumor progression were 22.25, 256.05, 5 232.67, 12.97 and 10.60, respectively. The patients were divided into two groups according to the above cut-off values, respectively. Kaplan-Meier survival analysis showed that there were statistically significant differences in PFS between the two group (all P <0.05). The MTV and TLG values were correlated with NCCN-IPI score, Ann Arbor stage, serum lactate dehydrogenase level, and C-MYC, BCL-2, BCL-6 gene rearrangement (all P <0.05). Univariate analysis showed that NCCN-IPI score >3, C-MYC, BCL-2, BCL-6 gene rearrangement positive, SUVmax≥22.25, MTV≥256.05 cm³, TLG≥5 232.67 g and TBR≥12.97 were adverse factors for prognosis (HR: 1.949-5.759, all P <0.05). Multivariate Cox regression analysis showed that C-MYC, BCL-2 gene rearrangement positive and TLG≥5 232.67 g were all independent risk factors affecting PFS (HR: 4.660, 3.350, 4.031, all P <0.05).

The ¹⁸F-FDG PET/CT metabolic parameters SUVmax, MTV, TLG, TBR and TLR can be used as important indicators to predict PFS of DLBCL patients, and combining clinicopathological features can better predict the prognosis of patients.