Prognostic significance of pretreatment ¹⁸F-FDG positron emission tomography/computed tomography in pediatric neuroblastoma

¹⁸F-2-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) shows tumor activity in most neuroblastomas, but the role of ¹⁸F-FDG PET/CT in neuroblastoma remains to be defined.

This study explored the prognostic significance of ¹⁸F-FDG PET in newly diagnosed neuroblastic tumors.

This retrospective study reviewed all ¹⁸F-FDG PET/CT examinations performed for a new diagnosis of suspected neuroblastoma. MYCN amplification status, tumor recurrence and survival were abstracted from the medical record. Primary tumors were manually segmented to measure maximum standardized uptake value (SUV_max), mean standardized uptake value (SUV_mean), tumor volume and total lesion glycolysis. Univariate and multivariable analyses using Cox proportional hazards regression testing assessed the predictive performance of PET indices for event-free survival and overall survival with thresholds determined using receiver operating characteristic curve analysis.

Fifty-five children were included, with a median age of 2.9 years (interquartile range [IQR] 1.8–3.0 years). SUV_max, tumor volume and total lesion glycolysis were higher in MYCN-amplified tumors (P=0.012, P<0.0001, P<0.0001, respectively) and in higher International Neuroblastoma Risk Group (INRG) stages (P=0.0008, P=0.0017, P=0.0017, respectively). After adjusting for age, tumor SUV_max (P=0.028) and SUV_mean (P=0.045) were associated with overall survival. An SUV_max threshold of 4.77 (P=0.028) best predicted overall survival, with median overall survival of 2,604 days (SUV_max>4.77) vs. >2,957 days (SUV_max≤4.77). No PET parameters were independently significantly associated with overall survival or event-free survival after controlling for MYCN status, stage or treatment risk stratification.

Tumor metabolic activity is higher in higher-stage MYCN-amplified neuroblastic tumors. Higher SUV_max and SUV_mean were associated with worse overall survival but were not independent of other prognostic markers.