Study of an image-derived SUV and a modified SUV using mouse FDG-PET

Area of Science:

• Nuclear medicine
• Preclinical imaging
• Radiochemistry

Background:

• Standard uptake value (SUV) in 2-deoxy-2-[18F]fluoro-D-glucose (FDG) Positron Emission Tomography (PET) is susceptible to variability from factors like renal function and measurement errors.
• Current SUV calculations do not account for plasma FDG clearance, leading to potential inaccuracies in assessing metabolic activity.

Purpose of the Study:

• To develop and validate an image-based method for calculating an image-derived SUV (iSUV) and a modified SUV (mSUV).
• To overcome the limitations of standard SUV measurements in preclinical FDG-PET studies, particularly in mouse models.

Main Methods:

• Utilized micro-PET/CT imaging in 31 tumor-bearing SCID mice approximately 60 minutes post-FDG injection.
• Derived body weight and injected dose from microPET/CT images to calculate iSUV.
• Quantified FDG volumes in the bladder and whole body from images to compute mSUV, comparing both iSUV and mSUV against standard SUV.

Main Results:

• The iSUV factor demonstrated a low average percentage error of -0.7% compared to the standard SUV factor.
• Linear regression showed a strong correlation between SUV and iSUV (slope=0.99, R=0.95).
• The mSUV exhibited reduced coefficient of variation and improved tumor-to-background separation compared to both SUV and iSUV.

Conclusions:

• The image-based method allows iSUV to serve as a reliable alternative to standard SUV when direct measurements are unavailable or inaccurate.
• mSUV effectively minimizes inter-subject variability and enhances the distinction between tumors and background tissues in mouse FDG-PET imaging.