Diagnosis, Treatment Response, and Prognosis: The Role of 18F-DOPA PET/CT in Children Affected by Neuroblastoma in Comparison with 123I-mIBG Scan: The First Prospective Study

Our purpose was to evaluate the diagnostic role of F-18-3,4-dihydroxyphenylalanine (DOPA) PET/CT at the time of staging in children with neuroblastoma and to investigate its ability to assess treatment response. We also investigated the prognostic value of F-18-DOPA PET/CT at the same time points. Methods: We enrolled children with neuroblastoma at onset. Before and after induction chemotherapy, all patients underwent F-18-DOPA PET/CT and I-123-metaiodobenzylguanidine (MIBG) scanning plus SPECT/CT. F-18-DOPA PET/CT results were compared with those of I-123-MIBG whole-body scanning (WBS). For each modality, patient-based analysis and lesion-based analysis were performed and sensitivity was calculated. We applied scoring systems to I-123-MIBG scanning and F-18-DOPA PET/CT (i.e.,I-123-MIBG WBS score and whole-body metabolic burden [WBMB], respectively) and evaluated the association between these parameters, the principal neuroblastoma risk factors, and outcome. Results: We enrolled 16 high-risk and 2 intermediate-risk neuroblastoma patients. On patient-based analysis, sensitivity in detecting primary tumors, soft-tissue metastases, and bone or bone-marrow metastases was 83%, 50%, and 92%, respectively, for I-123-MIBG WBS versus 94%, 92%, and 100%, respectively, for F-18-DOPA PET/CT. On lesion-based analysis, the sensitivity of F-18-DOPA PET/CT in detecting soft-tissue and bone or bone-marrow metastases was 86% and 99%, respectively-significantly higher than that of I-123-MIBG WBS, at 41% and 93%, respectively. After therapy, on patient-based analysis, the sensitivity in detecting primary tumors, soft-tissue metastases, and bone or bone-marrow metastases was 72%, 33%, and 38%, respectively, for I-123-MIBG WBS versus 83%, 75% and 54%, respectively, for F-18-DOPA PET/CT. On lesion-based analysis, the sensitivity of F-18-DOPA PET/CT in detecting soft-tissue and bone or bone-marrow metastases was 77% and 86%, respectively-significantly higher than that of I-123-MIBG WBS, at 28% and 69%, respectively. During follow-up, 8 cases of disease progression and 5 deaths occurred. On multivariate analysis, only posttherapeutic F-18-DOPA WBMB (>7.5) was associated with progression-free survival. Conclusion: F-18-DOPA PET/CT is more sensitive than I-123-MIBG WBS in staging neuroblastoma patients and evaluating disease persistence after chemotherapy. In a time-to-event analysis, posttherapeutic F-18-DOPA WBMB remained the only risk factor associated with disease progression.