Prognostic value of neutrophil-to-lymphocyte ratio and its correlation with fluorine-18-fluorodeoxyglucose metabolic parameters in intrahepatic cholangiocarcinoma submitted to 90Y-radioembolization.

Objective: The aim of this study was to investigate the prognostic value of neutrophil-to-lymphocyte ratio (NLR) and its relationship with several metabolic parameters obtained through PET in intrahepatic cholangiocarcinoma (ICC) submitted to radioembolization with Y-microspheres (Y-radioembolization).

Methods: Records of 20 subjects affected by ICC and submitted to Y-radioembolization were retrospectively evaluated. In all cases, pretreatment NLR was carried out and fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT was acquired with the calculation of the following metabolic parameters: maximum and mean standardized uptake value (SUVmax and SUVmean), metabolic total volume and total lesion glycolysis. After Y-radioembolization, all patients underwent regular imaging and laboratory follow-up.

Results: All patients presented F-FDG-avid hepatic tumors at pretreatment PET/CT examination. NLR significantly correlated with SUVmax (r = 0.64; P = 0.002) and SUVmean (r = 0.67; P = 0.001). After treatment with Y-microspheres, the mean OS resulted 12.5 ± 1.5 months. When the average pretreatment NLR value (i.e. 2.7) was used as a cutoff for patients' stratification, subjects with low NLR (<2.7) had a significantly longer OS than those with high NLR (>2.7). At Cox regression analysis including bilirubin, age, the presence of extrahepatic disease, hepatitis C virus/hepatitis B virus status and PET-derived parameters, only NLR resulted to be a significant predictor of OS (P = 0.01; hazard ratio = 13.1, 95% confidence interval = 1.6-102.7).

Conclusion: NLR is correlated with SUVmax-mean values in ICC and resulted to be an easy available predictor of survival in patients submitted to treatment with Y-microspheres.