The role of 18F-FDG PET/CT metabolic parameters in pediatric lymphoblastic lymphoma

Objective: This retrospective study aimed to evaluate the role of metabolic parameters of F-18-FDG PET/CT in pediatric lymphoblastic lymphoma (LBL).& nbsp;Methods: Thirty patients with LBL underwent 42 scans. Metabolic parameters including maximum standardized uptake value (SUVmax), total metabolic tumor volume (TMTV), and total lesion glycolysis (TLG) were measured at baseline PET/CT. Univariate and multivariate analysis for survival were performed to assess their prognostic value. Twelve patients underwent PET/CT after reinduction regime, and the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT for predicting relapse were calculated.& nbsp;Results: Patients with stage IV had a higher TMTV than those with stage III (P = 0.031). Besides, patients with T-LBL or mediastinal involvement had a high TMTV and TLG (P < 0.05). There was no significant difference in PET/CT metabolic parameters between patients with different outcomes (P > 0.05). Childrenwith a low TMTV (< 242.91 cm3) had a better 3-year EFS compared with those with a high TMTV (88.9% vs. 56.3%; P = 0.036). SUVmax and TLG were not predictive of EFS (P = 0.874; P = 0.152). However, none of the metabolic parameters of baseline PET/CT were independent prognostic factors for outcomes of pediatric LBL. PET/CT underwent after reinduction regime present with higher sensitivity (50% vs. 0%) and NPV (90% vs. 83.3%) for predicting relapse than CT alone.& nbsp;Conclusions: Metabolic parameters of baseline PET/CT were not predictive of outcomes in children with LBL. PET/CT done after the reinduction regime had better sensitivity and NPV than CT alone, and a negative scan could be a reliable indicator for sustained remission. (C) 2020 Sociedad Espanola de Medicina Nuclear e Imagen Molecular. Published by Elsevier Espana, S.L.U. All rights reserved.