Nuklearmedizin 2019; 58(02): 128
DOI: 10.1055/s-0039-1683537
Vorträge
Herz, Lunge und Gefäße
Georg Thieme Verlag KG Stuttgart · New York

Role of somatostatin receptor and FDG imaging in capturing plaque inflammation: a PET/CT analysis, corroborated by clinical data

F Fiz
1   UKT, Nuklearmedizin, Tübingen
,
A Nieri
2   IRCCS San Martino – IST, Nuklearmedizin, Genua
,
S Morbelli
2   IRCCS San Martino – IST, Nuklearmedizin, Genua
,
A Piccardo
3   Ospedali Galliera, Nuklearmedizin, Genua
,
M Riondato
4   ASL 5, Nuklearmedizin, La Spezia
,
A Ciarmiello
4   ASL 5, Nuklearmedizin, La Spezia
,
GM Sambuceti
2   IRCCS San Martino – IST, Nuklearmedizin, Genua
,
C la Fougère
1   UKT, Nuklearmedizin, Tübingen
› Institutsangaben
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Publikationsverlauf

Publikationsdatum:
27. März 2019 (online)

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    Ziel/Aim:

    Evidence indicates that atherosclerosis-related vascular inflammation can be measured with 18F-FDG-PET. However, background uptake, patients' comorbidities, and concomitant treatments may hamper signal semi-quantification. Up-regulation of somatostatin receptor subtype-2 occurs on activated macrophages and it has been suggested that somatostatin-receptor PET imaging may also capture vascular inflammation. This study aimed to compare the vascular distribution and biological determinants of plaque inflammation, as assessed by both 68Ga-DOTATOC and 18F-FDG-PET.

    Methodik/Methods:

    27 patients (12 males, mean age 69.4 ± 8, range 56 – 87) underwent an 18F-FDG and a 68 Ga-DOTATOC-PET within a four-week period for clinical reasons. Cardiovascular-risk was stratified using a simplified version of the Framingham model. VOIs were drawn on the entire aorta in both the 18F-FDG and the 68-Ga DOTATOC PET/CT. In these VOIs, SUVmean and SUVmax were normalized to blood activity to obtain the aortic target-to-background ratio (TBRmean and TBRmax). Differences in mean values and linear regression analysis were tested for these values and cardiovascular risk factors.

    Ergebnisse/Results:

    Aortic TBRmax was significantly higher on 68Ga-DOTATOC than on 18F-FDG-PET images (5.7 ± 2.2 Vs. 2 ± 1.2, p < 0.01) while no differences were highlighted for TBRmean. Cardiovascular risk score correlated with both TBRmean (R = 0.82 and 0.81 for 18F-FDG-PET and for 68Ga-DOTATOC, respectively, p < 0.001). Finally, only TBRmax of 68Ga-DOTATOC (and not of 18F-FDG) was higher in diabetics (n = 12) with respect to the remaining patients (6 ± 0.8 Vs. 4.9 ± 0.6, p < 0.05).

    Schlussfolgerungen/Conclusions:

    Correlations of both tracers uptake upon ongoing biological determinants of vascular inflammation confirm that PET might provide a window on plaque pathophysiology. In this framework, 68Ga-DOTATOC vascular signal demonstrated to better capture the presence of arterial hot spots and was able to better highlight plaque inflammation in diabetic patients.


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