Diffusion-weighted MRI for differentiating Wilms tumor from neuroblastoma

Area of Science:

• Pediatric oncology
• Radiology
• Medical imaging

Background:

• Wilms tumor (WT) and neuroblastoma (NB) are the most frequent pediatric abdominal malignancies.
• Accurate differentiation is crucial due to distinct treatment protocols.
• Diffusion-weighted imaging (DWI) offers potential for non-invasive tumor characterization.

Purpose of the Study:

• To evaluate the diffusion characteristics of WT and NB using DWI.
• To determine if apparent diffusion coefficient (ADC) values can differentiate between these two tumor types.
• To assess the reliability of ADC measurements for tumor differentiation.

Main Methods:

• Retrospective analysis of DWI data from 17 patients with histopathologically confirmed WT (7) and NB (10).
• Region-of-interest (ROI) based calculation of mean ADC values by two independent observers.
• Statistical comparison of ADC values and receiver operating characteristics (ROC) curve analysis for diagnostic performance.

Main Results:

• Mean ADC values were significantly lower for NB (0.524-0.529 ×10-3 mm2/s) compared to WT (0.768-0.787 ×10-3 mm2/s) (P < 0.011).
• Excellent interobserver agreement for ADC measurements (Intraclass correlation coefficient = 0.955).
• ROC analysis identified a cutoff ADC value of ≤0.645 ×10-3 mm2/s for differentiating NB from WT.

Conclusions:

• Apparent diffusion coefficient (ADC) values are significantly lower in neuroblastoma than in Wilms tumor.
• DWI, using ADC values, demonstrates a valuable role in differentiating pediatric NB from WT.
• High interobserver agreement supports the reliability of DWI for clinical application.