Metabolic Tumour Burden Assessed By ¹⁸F-FDG PET/CT Associated With Serum CA19-9 Predicts Pancreatic Cancer Outcome After Resection

PURPOSE:Tumor burden is one of the most important prognosticators for pancreatic duct adenocarcinoma (PDAC). The aim of this study was to investigate the predictive significance of metabolic tumor burden measured by 18F-fluorodeoxy glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with resectable PDAC.METHODS:One hundred twenty-two PDAC patients who received preoperative 18F-FDG PET/CT examination and radical pancreatectomy were included in the study. Metabolic tumor burden [metabolic tumor volume (MTV) and total lesion glycolysis (TLG)], pathological tumor burden (tumor size), serum tumor burden (baseline serum CA19-9 levels), and metabolic activity (maximum standard uptake value, SUVmax) were analyzed, respectively, and compared for prediction of overall survival (OS) and recurrence-free survival (RFS).RESULTS:MTV and TLG were significantly associated with baseline serum CA19-9 levels (P= 0.001 for MTV and P< 0.001 for TLG) and tumor size (P< 0.001 for MTV and P= 0.001 for TLG). Multivariate analysis showed that MTV, TLG, and baseline serum CA19-9 levels as either categorized or continuous variables, but not tumor size or SUVmax, were independent risk predictors for both OS and RFS. Time-dependent receiving operating characteristics analysis further indicated that better predictive performances for OS and RFS were achieved by MTV and TLG compared to baseline serum CA19-9 levels, SUVmax, and tumor size (P< 0.001 for all).CONCLUSIONS:MTV and TLG showed strong consistency with baseline serum CA19-9 levels in better predicting OS and RFS, and might serve as surrogate markers for prediction of outcome in patients with resectable PDAC.