PET in myeloma redefined: a comparative imaging study with FDG and fluorocholine PET/CT

Area of Science:

• Nuclear medicine
• Oncology
• Radiopharmaceuticals

Background:

• 18F-FDG-PET/CT has limitations in multiple myeloma (MM) evaluation due to variable hexokinase expression, potentially causing false-negative results.
• 18F-fluorocholine-PET/CT (FCH) targets membrane phospholipid synthesis, offering a potential alternative for MM imaging.

Purpose of the Study:

• To compare the diagnostic performance of 18F-fluorocholine-PET/CT (FCH) against 18F-FDG-PET/CT for multiple myeloma (MM) detection.
• To evaluate FCH-PET/CT's ability to reflect disease burden and correlate with laboratory markers in MM patients.

Main Methods:

• A single-center retrospective study involving 35 adult MM patients who underwent dual-tracer PET/CT within four weeks.
• Lesions were scored using Deauville-based criteria (IMPeTUs), and exploratory composite scores (hTepe and myPET) were calculated.
• Laboratory markers (M-protein, free light chains, bone marrow infiltration) were collected concurrently with imaging.

Main Results:

• FCH-PET/CT identified disease in 91% of patients with 94.1% sensitivity and 100% PPV, compared to FDG-PET/CT's 49% detection rate (50.0% sensitivity, 100% PPV).
• FCH demonstrated significantly higher hypermetabolic focus scores (median 4 vs. 1; p < 0.001) and correlated moderately with marrow plasma cell infiltration.
• FDG-PET/CT showed no consistent biochemical associations, while FCH uptake inversely correlated with hemoglobin and albumin.

Conclusions:

• FCH-PET/CT exhibits superior diagnostic performance over FDG-PET/CT in multiple myeloma, especially in red marrow-rich areas.
• FCH-PET/CT more reliably reflects MM disease burden and aligns better with laboratory markers.
• FCH-PET/CT holds potential utility for routine MM staging, residual disease assessment, and treatment response evaluation.