MRI reliability in pediatric abdominal lymph node metastases?

Area of Science:

• Pediatric oncology
• Medical imaging
• Diagnostic radiology

Background:

• Positron emission tomography-computed tomography (PET-CT) is effective for detecting lymph node metastases but involves radiation exposure.
• Repeated imaging, especially in pediatric patients, raises concerns about cumulative X-ray dose.
• Magnetic resonance imaging (MRI) offers a radiation-free alternative for visualizing abdominal lymph nodes and providing detailed anatomical and functional information.

Purpose of the Study:

• To assess the reliability of MRI in identifying lymph node metastases in pediatric abdominal malignancies.
• To determine if MRI can reduce X-ray dose by comparing its effectiveness against PET-CT.
• To evaluate MRI's diagnostic performance in pediatric abdominal cancer staging.

Main Methods:

• Retrospective single-center study of pediatric patients (<18 years) with abdominal solid malignant lesions (2015-2022).
• Defined 14 anatomical lymph node locations for comparison between MRI and PET-CT.
• Utilized Cohen's kappa test to quantify inter-modality agreement, with P < 0.05 considered significant.

Main Results:

• Included 25 pediatric patients (mean age 9.32 ± 16.9 years) with abdominal solid tumors.
• MRI reliability varied by lymph node station: almost perfect for internal iliac (k=0.915), porta hepatis, and aortocaval nodes.
• Fair reliability was noted for mesenteric lymph nodes (k=0.525), indicating location-dependent performance.

Conclusions:

• MRI demonstrates reliability comparable to PET-CT for detecting certain intra-abdominal metastatic lymph nodes in pediatric patients.
• MRI's effectiveness is location-dependent, with higher reliability in specific anatomical regions.
• MRI presents a viable, radiation-free option for evaluating lymph node involvement in pediatric abdominal malignancies, though careful consideration of anatomical site is necessary.