Metabolic tumour burden assessed by 18F-FDG PET/CT associated with serum CA19-9 predicts pancreatic cancer outcome after resection

Abstract

Tumour burden is one of the most important prognosticators for pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to investigate the predictive significance of metabolic tumour burden measured by (18)F-FDG PET/CT in patients with resectable PDAC. Included in the study were 122 PDAC patients who received preoperative (18)F-FDG PET/CT examination and radical pancreatectomy. Metabolic tumour burden in terms of metabolic tumour volume (MTV) and total lesion glycolysis (TLG), pathological tumour burden (tumour size), serum tumour burden (baseline serum CA19-9 level), and metabolic activity (maximum standard uptake value, SUVmax) were determined, and compared for their performance in predicting overall survival (OS) and recurrence-free survival (RFS). MTV and TLG were significantly associated with baseline serum CA19-9 level (P = 0.001 for MTV, P < 0.001 for TLG) and tumour size (P < 0.001 for MTV, P = 0.001 for TLG). Multivariate analysis showed that MTV, TLG and baseline serum CA19-9 level as either categorical or continuous variables, but not tumour 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 level, SUVmax and tumour size (P < 0.001 for all). MTV and TLG showed strong consistency with baseline serum CA19-9 level in better predicting OS and RFS, and might serve as surrogate markers for prediction of outcome in patients with resectable PDAC.