PET with Non-Standard Nuclides

Abstract

Driven by the ever-increasing availability of preclinical and clinical positron emission tomography (PET) scanners, the use of non-standard PET nuclides has been growing exponentially in the past decade. Largely complementary to the roles of the four standard PET nuclides ((15)O, (13)N, (11)C, and (18)F) in PET, non-standard PET nuclides enable the novel design and synthesis of a wider range of PET tracers to probe a variety of biological events. However, characterized by emitting high energy positrons and cascade gamma rays, non-standard PET nuclides with half-lives ranging from seconds to days must be judiciously chosen for specific applications. Generally, chemistries with non-standard PET nuclides are more manageable given a wealthy of existing standard operation procedures for the preparation of radiotracers for gamma scintigraphy or single photon emission tomography (SPECT). This review describes most of the non-standard PET nuclides that have recently been reported for basic PET research or clinical studies with focus on the unique features of their productions, radiochemical procedures, and applications. The main drawbacks of each nuclide are also discussed along with special considerations that must be given towards its practice use in PET.

Positron emission tomography for measurement of copper fluxes in live organisms

“…Positron emission tomography (PET) scanners currently manufactured have higher sensitivity and much better spatial resolution compared to the nuclear scintillation cameras previously used for studying copper metabolism in humans . Multiple positron emitter copper radioisotopes, which include 60 Cu ( t 1/2 23.7 min, 93% β + , 7% EC), 61 Cu ( t 1/2 3.32 h, 60% β + , 40% EC), 62 Cu ( t 1/2 9.74 min; 98% β + , 2% EC), and 64 Cu ( t 1/2 12.7 h, 17.4% β + , 43% EC, 39% β − ), were evaluated for the preparation of PET radiopharmaceuticals . Among these copper radioisotopes, 64 Cu is particularly suitable for the measurement of whole‐body copper fluxes in view of its desirable t 1/2 time of 12.7 h, the feasible production of 64 Cu with a biomedical cyclotron, and the delivery of 64 Cu from the production site to a laboratory or imaging facility at a distant location.…”

“…[37][38][39] Multiple positron emitter copper radioisotopes, which include 60 Cu (t 1/2 23.7 min, 93% ␤ + , 7% EC), 61 Cu (t 1/2 3.32 h, 60% ␤ + , 40% EC), 62 Cu (t 1/2 9.74 min; 98% ␤ + , 2% EC), and 64 Cu (t 1/2 12.7 h, 17.4% ␤ + , 43% EC, 39% ␤ − ), were evaluated for the preparation of PET radiopharmaceuticals. [40][41][42][43][44] Among these copper radioisotopes, 64 Cu is particularly suitable for the measurement of whole-body copper fluxes in view of its desirable t 1/2 time of 12.7 h, the feasible production of 64 Cu with a biomedical cyclotron, 45 and the delivery of 64 Cu from the production site to a laboratory or imaging facility at a distant location. The introduction of a smallanimal PET scanner [46][47][48] revived research interest in preclinical investigation of inherited and acquired copper metabolism disorders using 64 Cu (Table 1).…”

Mapping biological behaviors by application of longer-lived positron emitting radionuclides

“…For the development of 55 Co immuno-PET, high abundance of high-energy γ-rays distinct from β + -annihilation emissions, and long half-life of the daughter isotope 55 Fe ( t 1/2 = 2.73 years) are major concerns [27]. …”

Multimodality Imaging of RNA Interference

“…Since it is quantitative, non-invasive, sensitive, and clinically relevant, it is the ideal imaging technique for precise measurement of the pharmacokinetics and biodistribution of siRNA delivery vehicles, which is not only critical but also indispensable for the development of RNAi-based medicine. Although a wide variety of PET isotopes have been investigated in preclinical and clinical studies [15,21,24,84-89], only 64 Cu and 18 F have been used for RNAi-based research to date.…”