Potential Role of Somatostatin Receptor Scintigraphy for In Vivo Imaging of Vulnerable Atherosclerotic Plaques and Its Association with Myocardial Perfusion Imaging Finding: A Preliminary Study.

Objectives: This study was conducted to detect atherosclerotic plaques with somatostatin receptor scintigraphy (SRS) using Tc-99m-octreotide that binds to somatostatin receptor-2.

Methods: Of the 783 patients referred for myocardial perfusion imaging (MPI), 52 underwent additional chest single-photon emission computed tomography (SPECT) with Tc-99m-octreotide and participated in this study. In addition, 43 patients who underwent Tc-99m-octreotide scan for neuroendocrine tumor (NET) also received cardiac SPECT. Angiography was performed within 1 month after SRS for 19 patients who showed intensive uptake in SRS and had cardiac risk factors.

Results: Of 52 patients who underwent MPI and SRS, 15 showed intensive cardiac uptake in SRS. Moreover, of 43 patients who were referred for NET, 4 patients had marked cardiac uptake in SRS in the heart. Nineteen patients including 12 women and 7 men aged 28 to 84 (58±8.04) years underwent coronary angiography. SRS and angiography in the left anterior descending territory were concordant in 15/19 (79%) patients, whereas only 7/15 (46%) cases had concordant MPI and angiography results. In the right coronary artery territory, SRS and angiography were concordant in 16/19 (84%) cases, while MPI and angiography were concordant in 11/15 (73%) cases. In the left circumflex artery territory, SRS and angiography were concordant in 15/19 (79%) cases, whereas MPI and angiography were concordant in 6/15 (40%) cases. In the remaining 76 patients who did not undergo coronary angiography based on cardiovascular profile and SRS, no cardiac events occurred in a follow-up of 2-11 months (7.52±2.71).

Conclusion: Tc-99m-octreotide uptake was more concordant with coronary plaques relative to MPI findings, suggesting a potential role for Tc-99m-octreotide in the evaluation of atherosclerosis.