Abstract
Aim
The early diagnosis of atherosclerotic changes to prevent ischemic events represents
a clinical challenge.
Prostate-specific membrane antigen (PSMA) as an established diagnostic in the field
of prostate cancer also appears to detect neovascularization and inflammation in other
diseases. We hypothesized that it might be also suited for detection of inflammation
in atherosclerosis.
Methods
We analyzed data of 78 prostate cancer patients who received a PSMA ligand PET/CT
for re-staging. The cardiovascular risk factors (CVRF) of each patient were documented.
Target-to-background-ratios (TBR) were calculated from the individual uptake values
for three different sections of thoracic aorta [ascending (AA) and descending aorta
(AD), aortic arch (AoAC)]. Statistical analyses included a linear regression analysis
with the PSMA ligand uptake values of the different arterial segments versus different
CVRF as independent variables.
Results
The meanTBRmax was measured highest in the AoAC (1.66 ± 0.33) compared to both other
vessel sections (AA: 1.46 ± 0.21, p=0.001; AD: 1.59 ± 0.41, p=0.371). There was a
correlation between the PSMA ligand uptake in all measured segments of the aorta and
BMI, but only a significant correlation in the ascending aorta (r=0.347, p=0.001).
This was confirmed in a subgroup analysis, which showed significantly higher uptake
values in preadiposity (BMI >25) and obesity (BMI >30) patients in the ascending aorta
(p=0.048).
Conclusion
PSMA ligand uptake in the ascending aorta was linked to BMI. PET detection of vascular
PSMA ligand uptake may be indicative of vessel wall inflammation to some extent. However,
PSMA ligands appear to be less suitable than other tracers for this purpose, given
their absent correlation with most established CVRFs.
Keywords
PET - PSMA - Glutamate carboxypeptidase II - Atherosclerosis - Cardiovascular risk
factors
