Introduction: Central nervous system (CNS) recurrences in patients with high-risk neuroblastoma (HR-NBL) are rare, and their radiological characteristics are not well defined.
Methods: A secure web-based system has been developed by the Austrian Institute of Technology (AIT) within the frame of SIOPEN to perform central imaging review in selected populations of the current HR-NBL1/SIOPEN trial. Of 64 patients with CNS relapse identified in the SIOPEN-R-NET database, brain MRI/CT and MIBG scans were requested to 45 centers from 12 different countries. Imaging gathering and uploading was centralized in 6 centers. The review was performed by two independent pediatric radiologists and two nuclear medicine experts. Preliminary results are presented.
Results: Brain MRI/CT scans of 26 patients (41%) belonging to 18 centers from 8 countries could be retrieved and uploaded. Images were evaluable for 22/26 patients (85%). In 2 patients images at diagnosis only were provided, and in 2 patients the images were not from the time point of relapse. CNS relapse was confirmed in 21/22 (95%; 95% CI: 78%-99%) patients. The CNS lesions were parenchymal in 19/21, mainly located in the parietal lobe (9/19) and cerebellum (3/19), and as unique lesion in 11/19 patients. Leptomeningeal disease was found in 5/16 evaluable images (non-contrast CT scan in 5 patients). Edema around parenchymal lesion was observed in 14 patients, intratumoral hemorrhage in 11 patients, midline shift and hydrocephalus in 6 and 3 patients, respectively. Only 1/6 patients with brain MRI/CT scan performed at diagnosis had previous CNS involvement. CNS recurrence could be identified also by MIBG scan in 6/10 patients.
Conclusions: This work shows that central imaging review is feasible within a phase 3 academic international trial. It is of major help to better understand radiological features especially in rare subpopulations such as CNS recurrences, and should be prospectively considered in next trials