USPIO enhanced MR imaging in CNS tumors (UMIC): a study protocol

Area of Science:

• Neuro-oncology
• Medical Imaging
• Immunology

Background:

• Tumor-associated macrophages (TAMs) significantly drive brain tumor progression and resistance to therapies.
• There is a critical need for in vivo biomarkers to quantify TAM populations.
• Ultrasmall superparamagnetic iron oxide nanoparticles (USPIOs) offer potential as MRI contrast agents for TAM detection.

Purpose of the Study:

• To assess the feasibility of USPIO-enhanced MRI for noninvasively detecting TAM-associated inflammation.
• To investigate USPIO uptake, distribution, and clearance in the tumor microenvironment of gliomas and vestibular schwannoma (VS).
• To correlate MRI findings with cellular USPIO internalization in tumor tissue.

Main Methods:

• A pilot study involving patients with suspected transforming gliomas or VS undergoing serial MRI scans over three days.
• Administration of ferumoxytol (an FDA-approved USPIO agent) followed by MRI at immediate, 24-hour, and 48-hour post-infusion timepoints.
• Post-surgical analysis of tumor tissue to determine USPIO localization within macrophages.

Main Results:

• Characterization of USPIO uptake and clearance kinetics within the tumor microenvironment.
• Definition of the distribution and phenotype of USPIO-internalizing TAMs.
• Identification of optimal imaging parameters for TAM quantification using USPIO-enhanced MRI.

Conclusions:

• USPIO-enhanced MRI holds potential as a noninvasive biomarker for TAM-associated inflammation in brain tumors.
• This technique may facilitate patient stratification for immunomodulatory treatments.
• Further research can establish USPIO-enhanced MRI as a valuable clinical tool for neuro-oncology.