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

BACKGROUND

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

OBJECTIVE

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

MATERIALS AND METHODS

This retrospective study reviewed all F-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), mean standardized uptake value (SUV), 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.

RESULTS

Fifty-five children were included, with a median age of 2.9 years (interquartile range [IQR] 1.8-3.0 years). SUV, 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 (P=0.028) and SUV (P=0.045) were associated with overall survival. An SUV threshold of 4.77 (P=0.028) best predicted overall survival, with median overall survival of 2,604 days (SUV>4.77) vs. >2,957 days (SUV≤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.

CONCLUSION

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