Dynamic dual-tracer MRI-guided fluorescence tomography to quantify receptor density in vivo

Area of Science:

• Biomedical Imaging
• Molecular Imaging
• Cancer Research

Background:

• Cell surface receptor up-regulation is key in personalized cancer treatment.
• Quantifying in vivo receptor binding is challenging due to contrast agent pharmacokinetics.
• Noninvasive methods are needed for accurate receptor density estimation in tumors.

Purpose of the Study:

• To develop a dual-tracer optical technique for noninvasive estimation of specific receptor binding in cancer.
• To quantify available receptor density in vivo using a novel imaging approach.

Main Methods:

• Utilized a multispectral MRI-coupled fluorescence molecular tomography system.
• Simultaneously imaged two fluorescent tracers: one targeted, one reference.
• Applied a dual-tracer compartmental model to dynamic uptake data.

Main Results:

• Successfully estimated available receptor density in mice with deep-seated gliomas.
• Achieved an estimated receptor density of 2.3 ± 0.5 nM for EGF receptors.
• Results were consistent with invasive and ex vivo imaging methods.

Conclusions:

• The dual-tracer optical technique enables noninvasive quantification of specific receptor binding in cancer.
• This method provides accurate in vivo estimation of available receptor density.
• The approach holds promise for advancing personalized cancer treatment strategies.