Optimized dose regimen for whole-body FDG-PET imaging

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Radiochemistry

Background:

• Current European Association of Nuclear Medicine guidelines recommend FDG dose proportional to patient body mass for PET scans.
• Obese patients often experience degraded image quality with standard FDG dosing, indicating limitations of mass-proportional administration.
• A need exists to optimize FDG dose to maintain consistent image quality across varying patient body masses.

Purpose of the Study:

• To optimize the administered fluorodeoxyglucose (FDG) dose for whole-body positron-emission tomography (PET) scans.
• To determine if FDG dose should be a function of patient body mass or another patient-dependent parameter.
• To achieve more constant image quality in whole-body FDG-PET imaging, particularly for obese patients.

Main Methods:

• Performed FDG-PET imaging on two PET/CT scanners using a linear dose-to-body mass relation in 102 patients (46-130 kg).
• Assessed image quality via liver signal-to-noise ratio (SNR).
• Derived the best patient-dependent parameter for dose optimization and validated the new regimen in 42 patients and via phantom simulations.

Main Results:

• A linear dose-to-body mass approach resulted in decreased SNR with increasing patient weight.
• Patient body mass showed the highest correlation (R2) with image quality.
• An optimized quadratic dose regimen (Anew = c/t × m²) maintained constant SNR across different body masses, confirmed by simulations.

Conclusions:

• A quadratic relationship between FDG dose and patient body mass is recommended for whole-body PET imaging.
• This optimized dosing strategy ensures consistent image quality regardless of patient size.
• Both clinical data and simulations support the efficacy of the quadratic dose regimen.