Purpose: This retrospective study aimed to evaluate the prognostic value of metabolic parameters in baseline fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for pediatric lymphoblastic lymphoma (LBL). Method: Thirty patients with LBL who underwent baseline 18F-FDG PET/CT from April 2013 to November 2018 were enrolled. Their metabolic parameters including maximum standardized uptake value (SUVmax), total metabolic tumor volume (TMTV), and total lesion glycolysis (TLG) were measured and compared with those from different clinical characteristic groups. Event-free survival (EFS) and overall survival (OS) curves were constructed using the Kaplan–Meier method and compared with the log-rank test. Results: The patients with stage Ⅳ had higher TMTV than stage Ⅲ (mean 580.66cm³ vs. 176.52cm³; p=0.031). No statistical significance in SUVmax and TLG was observed between patients with stages Ⅲ and Ⅳ (p=0.061; p=0.291). After a median follow-up of 41.5 months (range of 1–86 months), the patients with a low TMTV (<242.91cm³) had better 3-year EFS rate compared with those with a high TMTV (88.9% vs. 56.3%; p=0.036). However, SUVmax and TLG were not predictive of EFS(p=0.874; p=0.152). Conclusions: TMTV may be a potential PET/CT metabolic parameter for predicting the prognosis of pediatric lymphoblastic lymphoma. A high TMTV indicates a poor outcome. However, SUVmax and TLG are not related to the prognosis of pediatric lymphoblastic lymphoma.

Purpose: To explore the correlations between neuron‑specific enolase (NSE) and the metabolic parameters such as the maximum uptake (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG), determined by fluorine‑18 fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) in pediatric patients with newly diagnosed neuroblastoma(NB). Method: Data from 43 patients with newly diagnosed NB between December 2013 and December 2019 were collected. The serum levels of NSE were measured at the time of diagnosis, and 18F-FDG PET/CT examinations were performed within 1 weeks. The metabolic parameters of the primary tumor lesion s such as SUVmax, MTV and TLG were calculated by 18F-FDG PET/CT. Pearson correlation analyses were applied to investigate the correlations between the serum levels of NSE and PET/CT findings. Result: NSE had strong correlations with SUVmax, MTV and TLG (r=0.521, P<0.001; r=0.520, P<0.001; r=0.442, P=0.003, respectively) using Pearson correlation analyses. The Mann-Whitney U tests showed that the values of SUVmax, MTV and TLG were significantly higher for the patients with NSE levels ≥100 ug/L (P=0.013, P=0.013 and P=0.002, respectively) and for patients with serum NSE levels larger than the cut-off value (P=0.004, P=0.008 and P<0.001, respectively). Conclusion: In patients with newly diagnosed NB, the metabolic parameters determined by 18F-FDG PET/CT could be considered as accurate markers of tumor burden, with MTV and TLG more sensitive than SUVmax. When abnormal NSE level were detected in a pediatric patient with NB, the higher the NSE level was, the larger the SUVmax MTV and TLG were.