Quantitative Magnetic Resonance Imaging Features Characterizing Pediatric Neuroblastic Tumors At Diagnosis
2Medical Imaging, The Hospital for Sick Children, Canada
Purpose: To determine the relationship between MRI features and malignancy of neuroblastic tumors at the time of diagnosis. In particular, the study aims to establish the diagnostic accuracy of quantitative MRI features (ADC value) to differentiate between malignant and benign types of neuroblastic tumors.
Methods: Cross-sectional study conducted retrospectively included a series of neuroblastic tumors cases from a single study site (SickKids hospital, Toronto, Canada), diagnosed between January 2008 to December 2020, who had undergone DWI-MRI at diagnosis. Image analysis was performed by two blinded radiologists, including ADC measurements of the tumor in two methods (Three small ROIs and one large ROI). The outcome measured is diagnostic accuracy of two quantitative MRI features: ADC derived from DWI and total tumor volume obtained from conventional MRI, compared to histopathology diagnosis.
Results: Forty patients (NB n=24, GNB n=6, GN n=10) were included in our study cohort, of which 18 were female and 22 were male, with a median age at diagnosis of 21 months (NB), 64 months (GNB) and 133 months (GN), ranging from 0-193 months. The area under the curve (AUC) for ADC from small region of interest (ROI) was 0.87 (95% CL 0.75-0.98); based on Youden`s index, an ADC cut-off value of 1.06 X 10^-3 mm^2/s was able to distinguish malignant from benign tumors with 83%(95% CI 68-98) sensitivity and 75% (95% CI 54-98) specificity. Tumor volume was not statistically significant.
Conclusions: In this study, ADC value was able to differentiate malignant from benign neuroblastic tumors with high accuracy. If the results are confirmed in a larger series, this feature can be used in the diagnostic assessment of neuroblastic tumors to help guide clinical decisions fro management.