Prognostic value of CT attenuation and FDG uptake of adipose tissue in patients with pancreatic adenocarcinoma

Abstract

AIM: To investigate the prognostic significance of computed tomography (CT) attenuation and 2[F-18]-fluoro-2-deoxy-n-glucose (FDG) uptake in subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) for predicting overall survival (OS) in patients with pancreatic adenocarcinoma. MATERIALS AND METHODS: Data were collected retrospectively from 66 patients with pancreatic adenocarcinoma who had undergone pretreatment combined FDG positron-emission tomography (PET)/CT imaging and subsequent curative or palliative treatment. Metabolic parameters of primary tumour including total lesion glycolysis (TLG) and heterogeneity factor were measured. Volume, CT attenuation (attenuation), and FDG uptake of SAT and VAT were derived from PET/CT acquisitions. Survival analysis using Cox proportional hazard modelling was performed to assess the relationship between both attenuation and FDG uptake of fat tissue and OS. RESULTS: During follow-up, 33 patients (50%) died and the median OS was 12 months. There were significant positive correlations between attenuation and mean standardised uptake values of both SAT (p<0.001, r=0.697) and VAT (p<0.001, r=0.742). Attenuation and FDG uptake of adipose tissue were significantly associated with heterogeneity factor and T stage. Patients with high FDG uptake and attenuation of SAT and VAT had significantly worse OS than those with low values. On multivariate analysis, attenuation of SAT (p=0.047) and VAT (p=0.021), and FDG uptake of VAT (p=0.005) were correlated significantly with OS after adjusting for age, sex, body mass index, TNM stage, and TLG. CONCLUSIONS: CT attenuation of SAT and VAT, and FDG uptake of VAT significantly correlated with OS in patients with pancreatic adenocarcinoma, independent of TNM staging and TLG. (C) 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.