Prognostic Significance of Neutrophil to Lymphocyte Ratio Dynamics in Patients with Hepatocellular Carcinoma Treated with Radioembolization Using Glass Microspheres

Purpose: To study the prognostic significance of neutrophil and lymphocyte dynamics in patients with hepatocellular carcinoma (HCC) treated with radioembolization. Methods: A retrospective, single-center review of clinical records and treatment parameters (liver volume treated, administered activity, and radiation dose) in consecutive patients who received radioembolization for HCC was performed between August 20, 2015, and May 24, 2019. Neutrophil and lymphocyte variables associated with overall survival (OS) were determined by Barcelona Clinic Liver Cancer (BCLC) stage and were correlated with radioembolization treatment parameters. Statistical methods included Wilcoxon signed-rank test, univariate, and multivariate Cox regression analysis; receiver operating characteristic analysis; and the Kaplan-Meier method. Results: One hundred sixty-three patients with a median 67.0 years of age were included for analysis. Eighty-one percent of patients received segmental radioembolization with a median treatment dose of 358 Gray (interquartile range 256–497). The post-treatment lymphocyte count decreased significantly in 94.5 % (p < 0.001) of patients but was not predictive of OS (p = 0.248). The pre-procedure neutrophil to lymphocyte ratio (NLR_pre) was not predictive of OS (p = 0.891), and the 1-month post-procedure NLR was a borderline independent predictor of OS (p = 0.05). The NLR ratio (NLRR = NLR_{post-procedure}/NLR_pre) (Hazard ratio [HR], 1.31; 95% Cl, 1.04-1.66) and change in NLR (ΔNLR= NLR_{post-procedure} - NLR_pre) (HR, 1.09; 95% CI, 1.02–1.15) were associated with worse OS in BCLC C patients. NLRR (> 3.17) and ΔNLR (> 3.74) were independent predictors when adjusted for tumor presentation, treatment parameters, and liver function. Volume of liver treated and administered activity positively correlated with NLRR and ΔNLR (p < 0.001). Conclusion: A decrease in lymphocyte count is common after radioembolization, but of little clinical impact. Neither pre-treatment or post-treatment NLR was a predictor of survival in our study population. NLRR and ΔNLR were independent predictors of survival in BCLC stage C disease and had positive correlations with volume of liver tissue treated and administered activity.