Incorporating Tissue Composition Information in Total-Body PET Metabolic Quantification of Bone Marrow through...

Area of Science:

• Nuclear Medicine
• Radiology
• Medical Imaging

Background:

• 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is crucial for bone marrow (BM) assessment in cancer staging and immunotherapy.
• Current BM quantification methods may be inaccurate due to the inclusion of non-metabolically active bone volume, potentially underestimating true FDG uptake.

Purpose of the Study:

• To demonstrate the bone-led tissue composition effect on BM metabolic quantification.
• To propose and validate a bone fraction correction (BFC) method using X-ray dual-energy computed tomography (DECT) to improve BM uptake accuracy.

Main Methods:

• Utilized dynamic 18F-FDG PET and DECT scans from five cancer patients on a total-body PET/CT system.
• Estimated voxel-wise bone volume fraction from DECT data.
• Incorporated bone fraction data into PET measurements to apply BFC and compared results with and without correction.

Main Results:

• Demonstrated the feasibility of voxel-wise material decomposition using DECT for metabolic BM imaging.
• Bone fraction correction (BFC) significantly increased standardized uptake value (SUV), K1, and Ki values in BM regions by an average of 13.28% (P<0.0001).
• Parametric imaging with BFC confirmed regional analysis, highlighting the impact of correction on BM quantification.

Conclusions:

• Current SUV and kinetic quantification of BM in PET are likely underestimated due to significant bone volume fraction.
• Incorporating tissue composition information via BFC can enhance the accuracy of BM metabolic quantification, particularly in the context of immunotherapy.