New SPECT and PET Radiopharmaceuticals for Imaging Cardiovascular Disease

Abstract

Nuclear cardiology has experienced exponential growth within the past four decades with converging capacity to diagnose and influence management of a variety of cardiovascular diseases. Single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) with technetium-99m radiotracers or thallium-201 has dominated the field; however new hardware and software designs that optimize image quality with reduced radiation exposure are fuelling a resurgence of interest at the preclinical and clinical levels to expand beyond MPI. Other imaging modalities including positron emission tomography (PET) and magnetic resonance imaging (MRI) continue to emerge as powerful players with an expanded capacity to diagnose a variety of cardiac conditions. At the forefront of this resurgence is the development of novel target vectors based on an enhanced understanding of the underlying pathophysiological process in the subcellular domain. Molecular imaging with novel radiopharmaceuticals engineered to target a specific subcellular process has the capacity to improve diagnostic accuracy and deliver enhanced prognostic information to alter management. This paper, while not comprehensive, will review the recent advancements in radiotracer development for SPECT and PET MPI, autonomic dysfunction, apoptosis, atherosclerotic plaques, metabolism, and viability. The relevant radiochemistry and preclinical and clinical development in addition to molecular imaging with emerging modalities such as cardiac MRI and PET-MR will be discussed.

Assessment of radiation dose in nuclear cardiovascular imaging using realistic computational models

“…60 The development of novel nuclear cardiology imaging probes for diagnosis of cardiovascular disease is an active research field. 53 Accurate dose calculations for representative patient groups at different ages are needed to optimize the dose regimens of various radiotracers and to investigate the collective radiation exposure and risks associated with nuclear medicine procedures. In this work, we estimated the S-values for Tl-201, Tc-99m, I-123, C-11, N-13, O-15, F-18, and Rb-82 using a new generation of age-and sex-dependent computational phantoms including the newborn, 1-, 5-, 10-, 15-yrold, and adult male and female and calculated organ absorbed doses and effective doses of 12 radiotracers used in nuclear cardiology based on the latest available dosimetric data.…”

Current and future trends in multimodality imaging of coronary artery disease

“…Some favorable characteristics of 201Tl are its high first-pass myocardial extraction and its capacity for myocardial viability assessment [9,10]. On the other hand, some limitations include higher rates of attenuation artifacts due to suboptimal photon energy, and higher radiation doses when compared with 99mTc-labeled tracers, without offering similar image quality [11].…”

“…99mTc-Sestamibi and 99mTc-Tetrofosmin are two of the most widely used and studied 99mTc-labeled tracers due to their favorable biological properties, such as high first-pass extraction, uptake proportional to flow, minimal redistribution and a relatively simple synthesis [10]. On the other hand, 99mTc-Teboroxime is not widely used due to the technical limitation that represents the need for an expeditious image acquisition due to a high initial uptake with rapid washout [10].…”

“…On the other hand, 99mTc-Teboroxime is not widely used due to the technical limitation that represents the need for an expeditious image acquisition due to a high initial uptake with rapid washout [10].…”

Pet Imaging and its Application in Cardiovascular Diseases

“…[11][12][13][14] Beyond molecular imaging, myocardial perfusion imaging with 82 Rb PET can also provide powerful and incremental risk stratification for patients with suspected or known coronary artery disease. 15 Additionally, 2-deoxy-2-( 18 F)fluoro-D-glucose ( 18 F-FDG) has been used as the gold standard for assessing myocardial glucose metabolism.…”