Whole-Body MRI vs. PET-CT in Pediatric Oncology: Enhancing Diagnostic Precision for Solid Tumors

Objective Pediatric solid tumors represent a significant portion of childhood cancer cases, requiring accurate and comprehensive imaging for effective staging, treatment planning, and long-term monitoring. Whole-body magnetic resonance imaging (WB-MRI) has emerged as a promising radiation-free alternative to traditional positron emission tomography-computed tomography (PET-CT), offering superior soft tissue contrast without the risks associated with ionizing radiation. This study aims to compare the diagnostic accuracy, sensitivity, and specificity of WB-MRI versus PET-CT in detecting primary tumors, metastases, and recurrences in pediatric solid tumors. Materials – Methods A retrospective analysis was conducted on 47 pediatric patients diagnosed with solid tumors between 2017 and 2020. Patients underwent both initial and follow-up imaging using PET-CT and WB-MRI. The study included cases with confirmed primary tumors, metastatic lesions, recurrences, and post-surgical negative findings. Patients who received chemotherapy, radiotherapy, or surgery after their PET-CT examinations were excluded from the analysis. The diagnostic performance of both modalities was assessed and compared. Results Pathological findings, including primary tumors, metastases, and postoperative recurrences, were identified in 74% of patients through PET-CT imaging. WB-MRI demonstrated an overall diagnostic accuracy of 97.47% for detecting primary tumors, metastatic disease, and recurrences, with a sensitivity of 97.01% and a specificity of 100%. While WB-MRI proved highly effective in identifying primary tumors and recurrences, it showed limitations in detecting certain types of metastases compared to PET-CT. Nonetheless, WB-MRI provided comprehensive whole-body assessment without the associated radiation risks. Conclusions WB-MRI is a highly reliable and accurate diagnostic tool for evaluating pediatric solid tumors, offering a non-ionizing alternative to PET-CT. Incorporating advanced sequences, particularly Short Tau Inversion Recovery (STIR), enhances WB-MRI's sensitivity for detecting primary tumors, screening for metastases, and monitoring recurrences. Given its superior safety profile and diagnostic accuracy, WB-MRI is recommended as a first-line imaging modality in pediatric oncology to optimize diagnostic outcomes and reduce radiation exposure in young patients.