Peptide Receptor Radionuclide Therapy Using 90Y- and 177Lu-DOTATATE Modulating Atherosclerotic Plaque Inflammation: Longitudinal Monitoring by 68Ga-DOTATATE Positron Emissions Tomography/Computer Tomography

<b>Background:</b> Atherosclerosis and its sequels, such as coronary artery disease and cerebrovascular stroke, still represent global health burdens. The pathogenesis of atherosclerosis consists of growing calcified plaques in the arterial wall and is accompanied by inflammatory processes, which are not entirely understood. This study aims to evaluate the effect of peptide receptor radionuclide therapy (PRRT) using ⁹⁰Y- and ¹⁷⁷Lu-DOTATATE on atherosclerotic plaque inflammation. <b>Methods</b>: Atherosclerotic plaques in 57 cancer patients receiving PRRT using ⁹⁰Y- and ¹⁷⁷Lu-DOTATATE were longitudinally monitored by ⁶⁸Ga-DOTATATE PET/CT. The target-to-background ratio (TBR) and overall vessel uptake (OVU) were measured in eight distinct arterial regions (ascending aorta, aortic arch, descending aorta, abdominal aorta, both iliac arteries, and both carotid arteries) to monitor calcified plaques. <b>Results:</b> PET/CT analysis shows a positive correlation between calcified plaque scores and the ⁶⁸Ga-DOTATATE overall vessel uptake (OVU) in cancer patients. After PRRT, an initially high OVU was observed to decrease in the therapy group compared to the control group. An excellent correlation could be shown for each target-to-background ratio (TBR) to the OVU, especially the ascending aorta. <b>Conclusions:</b> The ascending aorta could present a future reference for estimating generalized atherosclerotic inflammatory processes. PRRT might represent a therapeutic approach to modulating atherosclerotic plaques.