Metabolic parameters of pretreatment 2-[18F]fluoro-D-glucose positron emission tomography for prognosis in patients with gallbladder adenocarcinoma: a cohort study

Abstract

Background The incidence of gallbladder adenocarcinoma (GBA) is relatively low, yet it exhibits a high degree of malignancy and a significantly low 5-year survival rate. The aim of this study was to investigate the prognostic value of pretreatment 2-[ 18 F]fluoro-D-glucose positron emission tomography {2-[ 18 F]FDG PET} parameters in predicting outcomes for patients with GBA. Methods In total, 67 patients with GBA who underwent 2-[ 18 F]FDG PET/computed tomography (CT) before treatment were retrospectively analyzed at Chinese PLA General Hospital from January 2012 to June 2022. All patients were diagnosed by pathology, and their baseline characteristics and clinical data were collected. The metabolic PET parameters of the primary and metastatic lesions were measured, including the maximum and average standardized uptake values (SUVs), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). The prognostic significance of metabolic parameters and other clinical variables was assessed using Cox proportional hazards regression models. Differences in progression-free survival (PFS) and overall survival (OS) in relation to metabolic parameters were examined using the Kaplan-Meier method. Results During a median follow-up period of 14.2 months, 43 patients (64.2%) experienced tumor recurrence or progression, and 38 patients (56.7%) died of cancer. In the univariate Cox regression analysis, liver parenchymal invasion (P=0.001), lymph node metastasis (P=0.007), distant metastases (P=0.049), tumor differentiation (P=0.028), surgery (P=0.014), carcinoembryonic antigen (CEA) level (P=0.030), carbohydrate antigen 19-9 (CA19-9) level (P=0.003), TLG (P=0.005), MTV (P<0.001), sum of the TLGs of the primary and metastatic lesions (total TLG, tTLG) (P=0.001), and sum of the MTVs of the primary and metastatic lesions (total MTV, tMTV) (P<0.001) were significant predictors of PFS. In multivariate analysis, MTV was an independent predictor of PFS [hazard ratio (HR) =2.785; 95% confidence interval (CI): 1.204–6.441; P=0.017]. In the univariate Cox regression analysis, liver parenchymal invasion (P=0.001), lymph node metastasis (P=0.027), distant metastases (P=0.036), tumor differentiation (P=0.047), surgery (P=0.002), neutrophil-to-lymphocyte ratio (NLR) (P=0.011), CEA level (P=0.036), CA19-9 level (P<0.001), TLG (P=0.007), MTV (P<0.001), tTLG (P=0.003), and tMTV (P<0.001) were significant predictors of OS. In the multivariate analysis, higher CA19-9 levels >37 U/mL and a greater tMTV (HR =2.961; 95% CI: 1.092–8.024; P=0.033) were predictive of OS. Conclusions Our study results suggest that pretreatment 2-[ 18 F]FDG PET parameters can not only assist in the diagnosis of patients with GBA but may also serve as predictive factors for the prognosis of these patients and should thus be applied in their treatment.