Kinetic Modelling of Infection Tracers [18F]FDG, [68Ga]Ga-Citrate, [11C]Methionine, and [11C]Donepezil in a Porcine Osteomyelitis Model

الملخص EN

Introduction.

Positron emission tomography (PET) is increasingly applied for infection imaging using [18F]FDG as tracer, but uptake is unspecific.

The present study compares the kinetics of [18F]FDG and three other PET tracers with relevance for infection imaging.

Methods.

A juvenile porcine osteomyelitis model was used.

Eleven pigs underwent PET/CT with 60-minute dynamic PET imaging of [18F]FDG, [68Ga]Ga-citrate, [11C]methionine, and/or [11C]donepezil, along with blood sampling.

For infectious lesions, kinetic modelling with one- and two-tissue-compartment models was conducted for each tracer.

Results.

Irreversible uptake was found for [18F]FDG and [68Ga]Ga-citrate; reversible uptake was found for [11C]methionine (two-tissue model) and [11C]donepezil (one-tissue model).

The uptake rate for [68Ga]Ga-citrate was slow and diffusion-limited.

For the other tracers, the uptake rate was primarily determined by perfusion (flow-limited uptake).

Net uptake rate for [18F]FDG and distribution volume for [11C]methionine were significantly higher for infectious lesions than for correspondingly noninfected tissue.

For [11C]donepezil in pigs, labelled metabolite products appeared to be important for the analysis.

Conclusions.

The kinetics of the four studied tracers in infection was characterized.

For clinical applications, [18F]FDG remains the first-choice PET tracer.

[11C]methionine may have a potential for detecting soft tissue infections.

[68Ga]Ga-citrate and [11C]donepezil were not found useful for imaging of osteomyelitis.