Impact of Tracer Dose Reduction in ¹⁸F-FDG PET on Texture Features: A Phantom and Patient Study

Ziel/Aim Textural features (TFs) extract the available image data by translating the information of each voxel into a quantitative value and can also perform analysis of the percentage or spatial distribution on different levels of complexity. Here, we aimed to evaluate the influence of tracer dose reduction in ¹⁸F-FDG-PET on TFs in phantom as well as patient data.

Methodik/Methods PET data were acquired with a Siemens mMR PET/MR scanner. Overall, 42 TFs were evaluated in a NEMA phantom at measured and simulated doses stepwise from 100% down to 25% of ¹⁸F. In addition, the same TFs were assessed in ¹⁸F-FDG-PET datasets of 15 patients that were simulated from 3.0 down to 0.5 MBq/kgBW in intervals of 0.25. TFs in two VOIs placed in physiological tissue of the right and left liver lobe were calculated and linear correlations and coefficients of variation analysis performed.

Ergebnisse/Results Phantom studies showed no significant differences in both measured and simulated doses in all TFs (p>0.05). Also 40 TFs showed the same behaviour over dose reduction regarding difference in the same group (measured or simulated) and for 28 TFs a linear behaviour over dose reduction for measured and simulated doses could be validated.

In patient data a clear influence of VOI size on TF variability could be shown, with a trend for injected tracer dose on TF variability. 14 TFs could be identified which showed a linear behavior in both NEMA phantom and patient data and therefore could be seen as robust regarding dose reduction. Out of this GLCM Homogeneity 2, GLCM Entropy and GLZSM ZSN are from special interest because they have been described as preferentially considerable for tumor heterogeneity characterization.

Schlussfolgerungen/Conclusions Dose reduction is a next goal in PET-imaging. Although this is just a first examination addressing the influence of tracer dose reduction on TFs, we could show that there are several TFs, including some TFs with high potential regarding tumor analysis showing a robust and linear behaviour over dose reduction.

Publication History

Article published online:
14 April 2022