Neuroblastoma, the most common extracranial solid tumor in children, arises from embryonal neural crest progenitor cells. With a common origin of neuroendocrine cytology, this otherwise highly variable disease can be imaged with high sensitivity by exploiting the underlying biochemistry of the nervous system – namely with radiolabeled I-123 metaiodobenzylguanidine (MIBG), a norepinephrine analog. Imaging with MIBG over time can serve several key roles, including providing accurate stage at diagnosis, response assessment following therapy, and detection of recurrent disease. Moreover, when using the Curie score, a standardized and validated assessment of MIBG uptake on planar imaging, valuable prognostic information can be elucidated both at time of diagnosis and following induction therapy. Through the utilization of the same underlying physiologic principles, I-131 MIBG could be administered for an intended therapeutic effect, targeting sites of tracer uptake. The purpose of this educational exhibit is to review the process of quantifying and assigning a Curie score in the evaluation of pediatric neuroblastoma using I-123 MIBG planar imaging. Using a pictorial review of various I-123 MIBG positive cases, we will highlight normal MIBG uptake, distribution, and excretion. Through the inclusion of case examples that demonstrate various stages of disease, differing sites and severity of pathologic activity will be highlighted. Finally, the prognostic significance of the Curie scoring paradigm over time will be illustrated, specifically at the time of diagnosis and post-induction with I-123 MIBG, and in the post-therapy setting with I-131 MIBG. Read More

Meeting name: SPR 2025 Annual Meeting , 2025

Authors: Berg Sarah, States Lisa

Keywords: Nuclear Medicine, MIBG, Neuroblastoma

Hereditary paraganglioma-pheochromocytoma syndromes (PGL/PCC) are marked by the presence of multiple and/or multifocal neoplasms of neuroendocrine origin, namely paragangliomas and pheochromocytomas. Though considered an overarching familial cancer syndrome, PGL/PCC can be further characterized based on cellular origin, secretory status, and predisposing genetic mutation, comprising at least 6 distinct subtypes of the disease. Because of the unique metabolic features of neuroendocrine neoplasms, distribution of disease in patients with PGL/PCC can often be precisely evaluated via targeted nuclear medicine radiotracers. However, the true extent and burden of disease involvement may be artificially suppressed owing to the variability in tumor differentiation and subsequent metabolic function. We present the case of a 15-year-old with hereditary paraganglioma-pheochromocytoma syndrome who was evaluated with several distinct nuclear medicine radiotracers – DOTATATE, FDG, and MIBG – with synergistic findings. Initial evaluation with DOTATATE PET/CT demonstrated multiple somatostatin-receptor positive lesions in the neck, chest, and abdomen. Further assessment with MIBG SPECT/CT highlighted the previously seen, dominant abdominal mass, though otherwise revealed less abnormal foci of disease than that seen on preceding DOTATATE study. Finally, whole body FDG PET/MRI was utilized, revealing intense gastric avidity corresponding to gastrointestinal stromal tumor, with milder uptake at the other sites of previously characterized malignancy. This case emphasizes the underlying heterogeneity of tumors which may arise in patients with PGL/PCC and lends credence to the value of multi-tracer imaging for true disease staging purposes. Read More

Meeting name: SPR 2025 Annual Meeting , 2025

Authors: Berg Sarah, States Lisa

Keywords: Nuclear Medicine, PET

PET/MRI plays a significant role in Pediatric Oncology, but its implementation in Pediatric Neuro-Oncology has not been well established. PET/MRI addresses a major challenge in pediatrics by providing capability for serial imaging to track disease response to therapy, while minimizing radiation exposure and sedation events. PET/MRI has become a critical imaging modality in the management of pediatric brain neoplasms and metastases, aiding in diagnosis, staging, treatment planning, and follow-up, all while reducing radiation burden, minimizing time spent in the hospital, and reducing the number of sedation events. At our tertiary center for pediatric care, we have gained extensive experience in utilizing hybrid PET/MRI to manage complex cases referred from multiple institutions. We present a series of cases where hybrid PET/MRI provided critical information for patient management including nasopharyngeal rhabdomyosarcoma, refractory metastatic germ cell tumor, and neuroblastoma. We offer a forward-looking perspective on the current role of FDG PET/MRI and future applications of amino acid PET in improving patient outcomes and its role in distinguishing tumor progression from post-treatment changes. Amino acid PET/MRI use cases were compiled from literature review and demonstrate definitive roles of amino acid PET/MRI in decision making in brain tumor diagnosis, immediate post-surgical assessment, and delayed treatment response assessment. 18F-FDG PET/MRI representative cases from clinical practice: Case 1. 18 year old male with refractory metastatic germ cell tumor with anterior mediastinal mass and intracranial metastasis Clinical Problem: Whole body evaluation in addition to detailed analysis of brain metastases in time efficient manner. Imaging Solution: PET/MRI allowed detailed evaluation of hypermetabolic metastatic disease to the mediastinum and lungs and further detailed delineation of hemorrhagic brain metastases. Case2. 4 year old boy with history of nasopharyngeal rhabdomyosarcoma with cerebellar metastasis who underwent resection and chemoradiation. Clincial Problem: How to monitor nasopharyngeal mass after treatment in the setting of extensive postsurgical changes on MRI Imaging Solution: PET/MRI provides an excellent imaging method for monitoring disease recurrence in the setting of post-treatment changes in nasopharyngeal location. Recurrent tumor was identified as hypermetabolic lesion, while MRI was not definitive. Read More

Meeting name: SPR 2025 Annual Meeting , 2025

Authors: Maleki Nazanin, Amiruddin Raisa, States Lisa, Aboian Mariam

Keywords: PET-MRI, Pediatric Imaging, Brain Tumors