Preoperative 11 C-Methionine PET-MRI in Pediatric Infratentorial Tumors

Area of Science:

• Neuroimaging
• Pediatric Oncology
• Radiology

Background:

• Magnetic Resonance Imaging (MRI) is standard for pediatric brain tumors.
• Amino acid Positron Emission Tomography (PET) offers supplementary diagnostic information.
• Simultaneous PET-MRI acquisition enhances tumor assessment and reduces radiation exposure.

Purpose of the Study:

• To evaluate the complementary role of amino acid PET and MRI in characterizing pediatric posterior fossa tumors.
• To correlate PET-MRI findings with histopathological results for improved preoperative diagnosis.
• To assess the utility of advanced imaging in evolving patient management strategies.

Main Methods:

• Prospective study of children with newly diagnosed posterior fossa tumors undergoing 11C-methionine (MET) PET-MRI.
• Visual and semiquantitative assessment of PET-MRI images.
• Correlation analysis of minimum apparent diffusion coefficient (ADC min), contrast enhancement, SUV max, and metabolic tumoral volume with histopathological classification (WHO 2021).

Main Results:

• All ten included pediatric posterior fossa tumors showed increased MET uptake.
• Moderate negative correlation between ADC min and SUV max (r = -0.39).
• Moderate positive correlation between metabolic tumoral volume and lesion diameter (r = 0.34).
• Higher SUV max values observed in higher WHO grade tumors.

Conclusions:

• Preoperative 11C-MET PET-MRI provides complementary information for characterizing pediatric infratentorial tumors.
• Combined imaging aids in differentiating tumor grades and types.
• This approach supports enhanced preoperative tumor characterization in pediatric neuro-oncology.