Radiogenomics of neurogenic tumors in children: a retrospective study

INTRODUCTION: Extracranial neurogenic tumors in children are represented by neoplasms of the sympathetic nervous system and adrenal medulla: ganglioneuromas, ganglioneuroblastomas and neuroblastomas. The main prognostic factors used to stratify patients into risk groups and, in many ways, determine the effectiveness of treatment are the histological type of the tumor and the presence of MYCN gene amplification. OBJECTIVE: To evaluate the capabilities of quantitative MRI to determine the histological variant of neurogenic tumors and predict the presence of MYCN gene amplification in children. MATERIALS AND METHODS: We retrospectively analyzed the data of 110 patients with primary peripheral neurogenic tumors who underwent therapy or received an advisory opinion at the D.Rogachev National Medical Research Center for Pediatric Orthopedics and Pediatric Orthopedics in the period from 2012 to 2022. with diagnoses of ganglioneuroma — 12, mixed ganglioneuroblastoma — 10, neuroblastoma — 88. The age of patients at the time of diagnosis ranged from 15 days to 16 years, median age — 17 months. Before surgery and therapeutic interventions, all patients underwent diffusion-weighted MRI and a tumor biopsy to determine MYCN gene amplification using FISH. Statistics: To determine the threshold values of the apparent diffusion coefficient (ADC) of neurogenic tumors of various histological structures, as well as with the presence and absence of MYCN gene amplification, ROC analysis (receiver operating characteristic) was used. Differences in qualitative parameters in the studied groups of patients were analyzed using the χ2 test, and quantitative ones — using the Mann-Whitney and Kruskal-Wallis tests. RESULTS: Threshold values of the ADC index were determined to reliably differentiate neurogenic tumors rich in Schwann stroma (ganglioneuromas and ganglioneuroblastomas, ADC≥1.25 mm 2 /s) and neuroblastomas, as well as neuroblastomas without MYCN gene amplification (0.78<ADC <1.25 mm 2 /s) and with the presence of amplification (ADC≤0.78 mm 2 /s). In the first case, sensitivity was 0.95, specificity — 0.94; in the second — 0.94 and 0.75, respectively. DISCUSSION: Our data indicate the possibility of separating histological types of neurogenic tumors on the basis of quantitative MRI; the ADC value makes it possible to differentiate ganglioneuromas and ganglioneuroblastomas from neuroblastoma, as well as to distinguish neuroblastoma with the presence of MYCN gene amplification and without this genetic event. Non-invasive quantitative MRI makes it possible to assess the entire tumor volume at the diagnostic stage, and an extremely low ADC value radiogenomic sing for the presence of MYCN gene amplification in neuroblastoma. CONCLUSION: Quantitative MRI with determination of ADC of neurogenic tumors allows not only to separate the histological variants of neurogenic tumors, but also to predict the presence of MYCN gene amplification as the most unfavorable genetic marker of neuroblastomas.