Prognostic value of 18F-FDG PET/CT metabolic parameters in locally recurrent nasopharyngeal carcinoma receiving chemoradiotherapy and their relationships with peripheral blood inflammation markers / 中华核医学与分子影像杂志

ABSTRACT

Objective:To investigate the prognostic value of 18F-FDG PET/CT in patients with locally recurrent nasopharyngeal carcinoma (NPC) receiving chemoradiotherapy, and relationships between different metabolic parameters and peripheral blood inflammation markers. Methods:From January 2013 to June 2016, the data of 56 patients (40 males, 16 females, age 27-81 years) with locally recurrent NPC receiving chemoradiotherapy in the First People′s Hospital of Foshan were retrospectively analyzed. The SUV max, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were determined by 18F-FDG PET/CT and peripheral blood inflammation markers within 1 week before treatment were measured. Spearman rank correlation analysis was used to estimate the correlations between metabolic parameters and inflammation markers. According to the ROC curve, the best cut-off values of the SUV max, MTV and TLG were obtained and used to group patients. The Kaplan-Meier method and Cox regression were used to conduct univariate analysis and multivariate analysis of 3-year locoregional failure-free survival (LRFFS) and 3-year overall survival (OS) in patients with locally recurrent NPC. The prognostic value of metabolic parameters in patients with early and advanced recurrent T(rT) stages were compared. Results:MTV was positively correlated with neutrophils, neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and high-sensitivity C-reactive protein (hs-CRP) before treatment in patients with locally recurrent NPC ( rs values 0.30, 0.30, 0.28, 0.27, all P<0.05); TLG was positively correlated with neutrophils, monocytes, NLR and PLR ( rs values 0.30, 0.28, 0.32, 0.30, all P<0.05). But there were no correlations between SUV max and peripheral blood inflammation markers ( rs values from -0.18 to 0.24, all P>0.05). SUV max was an factor affecting 3-year LRFFS of patients undergoing radiotherapy and chemotherapy (hazard ratio ( HR)=3.815(95% CI 1.278-11.388), P=0.016), while rT stage and MTV were prognostic factors for 3-year OS ( HR values 4.492(95% CI 1.474-13.688), 7.238(95% CI 1.653-31.688), P values 0.008, 0.009). For patients with advanced rT (rT3-4), the 3-year OS of the MTV≥6.84 cm 3 group was significantly lower than that of MTV<6.84 cm 3 group ( χ2=6.99, P=0.008). Conclusions:SUV max of tumor and MTV before treatment have important prognostic values in patients with locally recurrent NPC receiving chemoradiotherapy, but their predictive effects on prognosis are not the same. The varying effects of local inflammation on metabolic parameters may be one of the important reasons lead to that difference.