[⁶⁸Ga]Ga-DOTA-TOC positron emission tomography outperforms [¹⁸F]FDOPA and [¹⁸F]FDG PET in pediatric neuroblastoma...

Neuroblastoma is a heterogeneous pediatric malignancy with variable imaging characteristics. Neuroblastoma tumors express SSTR receptors, but the role of [⁶⁸Ga]Ga-DOTA-TOC in neuroblastoma remains unclear. This study aimed to compare the diagnostic accuracy of [⁶⁸Ga]Ga-DOTA-TOC PET against [¹⁸F]FDOPA PET and [¹⁸F]FDG PET in neuroblastoma.

Patients with histologically confirmed neuroblastoma were prospectively recruited between September 2021 and September 2024. All participants underwent PET imaging using three radiotracers. Each modality was assessed for lesion detectability. Bone lesions were evaluated using the SIOPEN system. PET findings were interpreted as true lesions following multidisciplinary tumor board discussions and confirmed with follow-up imaging. Detectability across modalities was compared using Cochran's Q test, while maximal standardized uptake values (SUVmax) were analyzed using repeated measures ANOVA and post hoc pairwise comparisons.

Fifteen patients (mean age 6.1 ± 3.4; 6 females and 9 males) underwent paired PET imaging using three different radiotracers, predominantly stage M (13/15 patients) and high risk (14/15 patients). In patient-based analysis, [¹⁸F]FDG PET failed to detect active disease in two patients, resulting in a detection rate of 86.7% (13/15), while [⁶⁸Ga]Ga-DOTA-TOC and [¹⁸F]FDOPA PET successfully identified all patients (15/15, 100%). A total of 203 lesions were identified in the lesion-based analysis. [⁶⁸Ga]Ga-DOTA-TOC PET demonstrated superior detectability (199/203 lesions, 98.0%), compared to [¹⁸F]FDOPA PET (129/203, 63.5%) and [¹⁸F]FDG PET (122/203, 60.1%) (p < 0.001). SUVmax was highest for [⁶⁸Ga]Ga-DOTA-TOC PET (5.5 ± 4.0), followed by [18F]FDG PET (1.8 ± 1.4) and [¹⁸F]FDOPA PET (0.6 ± 0.5) (p < 0.001). Organ-based analysis revealed that [⁶⁸Ga]Ga-DOTA-TOC provides superior detection rates in lymph node (55/57, 96.5%), soft tissue (43/43, 100%), bone and bone marrow (89/89, 100%) metastases. SUVmax was generally higher on [⁶⁸Ga]Ga-DOTA-TOC PET/CT for both primary lesions and metastases (all p < 0.001), except in the liver. The majority of lesions (170/203, 83.7%) exhibited a Krenning score of 2 or higher.

The enrichment of somatostatin receptors in neuroblastoma makes [⁶⁸Ga]Ga-DOTA-TOC PET a highly effective detection tool compared to [¹⁸F]FDOPA PET and [¹⁸F]FDG PET. A multimodal imaging approach can enhance disease evaluation and guide personalized therapeutic strategies, potentially facilitating radioligand therapy.