Prognostic Value Of Pretherapeutic Baseline ¹⁸F-FDG PET/CT In Pediatric Patients With Neuroblastoma

Objective:To evaluate the prognostic value of metabolic parameters measured by pretherapeutic ¹⁸F-deoxyglucose(¹⁸F-FDG)positron emission tomography/computed tomography（PET/CT）in pediatric patients with neuroblastoma.Methods:37 patients[20 male and 17 female;median age,32m（range,4-96m）]with newly diagnosed NB in the Hebei General Hospital from October 2013 to October 2019 who underwent ¹⁸F–FDG PET/CT were retrospectively reviewed.Imaging classification was stageâ… in 7patients（18.9%）,stageâ…¡in 5（13.5%）,stageâ…¢in 4（10.8%）,stageâ…£in 21 patients（56.8%）.Patients were divided into progression group（n=15）and non-progression group（n=21）.Prognostic information included progression-free survival（PFS）and overall survival（OS）were recorded.Disease progression was defined as≥20%increase in the size of known neuroblastoma lesions from baseline or occurrence of newly developed metastases on follow-up imaging examinations,and the death caused by NB was also classified as disease progression.PFS was defined as the time from the first diagnosis to disease progression or the death or to the last clinical follow-up.Over survival（OS）was defined as the time from the first diagnosis to death or the last follow-up.According to the baseline¹⁸F-FDG PET/CT images before treatment,the following PET/CT parameters were obtained.（1）Pmax:maximum standardized uptake value（SUVmax）of primary tumor lesions;（2）Tmax:the maximum standardized uptake value（SUVmax）of all tumor lesions（including primary tumor lesions and metastatic lesions）;（3）Tmax/Lmean:the ratio of Tmax to average standardized uptake value（SUVmean）of normal liver tissue;（4）metabolic volume of primary tumor（MTV）;（5）total lesion glycolysis of primary tumor（TLG）;（6）the location of primary tumor;（7）the maximum diameter of the primary tumor.The data obtained from the clinical medical records included age,sex,serum lactate dehydrogenase（LDH）,serum neuron specific enolase（NSE）,serum ferritin and clinical stage.PET/CT and clinical parameters were compared between two groups using independent t test,Wilcoxon symbolic rank sum test and Fisher’s exact test.The cutoff values of metabolic parameters and clinical parameters were determined by receiver operating characteristic curve（ROC）analysis.Univariate Kaplan-Meier analysis was used to evaluate the effects of age,LDH,NSE,ferritin,maximum diameter of primary tumor,Pmax,Tmax,Tmax/Lmean,MTV and TLG on 2-year PFS and OS.Multivariate Cox proportional hazard regression analysis was used to evaluate the effects of multiple parameters P<0.05 in univariate analysis on 2-year PFS and OS.Survival curves were estimated using the Kaplan-Meier method to calculate cumulative PFS and OS rates.The effects of age,LDH,NSE,ferritin,maximum diameter of primary tumor,Pmax,Tmax,Tmax/Lmean,MTV and TLG on 2-year PFS and OS were evaluated in 21 patients with stage IV disease.Results:Significant differences were observed in Pmax（7.20±3.60vs.5.20±2.00,t=2.198,P=0.035）,Tmax（7.50±3.60 vs.5.45±2.10,t=2.167,P=0.037）and Tmax/Lmean（7.60±4.30 vs.4.70±1.70,t=2.851,P=0.007）between the progression group and the non-progression group.ROC analysis showed that the cutoff values for maximum diameter of primary tumor,Pmax,Tmax,Tmax/Lmean,MTV,TLG,LDH and ferritin were 82.60mm,5.60,5.25,6.90,267.85cm³,527.07g,700.00U/L and 602.60ug/L,respectively.Univariate analysis showed that serum LDH,serum NSE,serum ferritin,maximum diameter of primary tumor,Pmax,Tmax,Tmax/Lmean,MTV and TLG were prognostic factors for PFS,while serum LDH,serum NSE,maximum diameter of primary tumor,Pmax,Tmax/Lmean,MTV and TLG were prognostic factors for OS.Multivariate analysis revealed that Serum LDH,serum ferritin,Tmax/Lmean and MTV were independent prognostic factors for PFS,while MTV was independent prognostic factor for OS.MTV was the only independent prognostic factor for PFS and OS.In 21 NB patients in stage IV,serum LDH,serum ferritin,maximum diameter of primary tumor,Pmax,Tmax/Lmean,MTV and TLG were prognostic factors for PFS.MTV and TLG were the prognostic factors for OS.Conclusion:Patients with higher Pmax,Tmax,Tmax/Lmean,MTV,TLG and larger maximum diameter of primary tumor of NB have worse prognosis.MTV measured by PET/CT was the only independent prognostic factor for PFS and OS.Pretherapeutic ¹⁸F-FDG PET/CT can provide reliable prognostic information for pediatric patients with neuroblastoma.