68Ga-Labeled Radiopharmaceuticals for Positron Emission Tomography

Abstract

68 Ga is a promising emerging radionuclide for positron emission tomography (PET). It is produced using a 68 Ge/ 68 Ga-generator, and thus, would enable the cyclotronindependent distribution of PET. However, new 68 Galabeled radiopharmaceuticals that can replace 18 F-labeled agents like [ 18 F]fluorodeoxyglucose (FDG) are needed. Most of the 68 Ga-labeled derivatives currently used are peptide agents, but the developments of other agents, such as amino acid derivatives, nitroimidazole derivatives, and glycosylated human serum albumin, are being actively pursued in many laboratories. Thus, appearance of new 68 Ga-labeled radiopharmaceuticals with high impact are expected in the near future. Here, we present an overview of 68 Ga-labeled agents in terms of their clinical significances and relevances to the management of certain tumors, and pertinent pre-clinical developments.

Immuno-PET Imaging and Radioimmunotherapy of 64Cu-/177Lu-Labeled Anti-EGFR Antibody in Esophageal Squamous Cell Carcinoma Model

“…68 Ga is a short-lived positron emitter (half-life, 68 min) and is readily produced from a commercially available 68 Ge/ 68 Ga generator. Recently, 68 Ga-based radiopharmaceuticals have been used extensively in small-size molecules such as peptides, antibody fragments, Affibody molecules, or nanobodies with faster pharmacokinetics and bioavailability (21). 68 Ga-labeled somatostatin receptor-targeting compounds have been applied for patients with neuroendocrine tumors.…”

Development of Small-Animal PET Prototype Using Silicon Photomultiplier (SiPM): Initial Results of Phantom and Animal Imaging Studies

“…Finally, a 68 Ga-RGD (angiogenesis PET agent) scan of a 24.8-g BALB/c nude mouse bearing a malignant glioma cell line (U87MG) on the left shoulder was acquired for 51 min. The PET scan was started 15 min after the intravenous injection of 33.5 MBq (0.91 mCi) of 68 Ga-RGD (22,23).…”

Whole-Body Distribution and Radiation Dosimetry of68Ga-NOTA-RGD, a Positron Emission Tomography Agent for Angiogenesis Imaging

“…4 Integrin a v b 3 is a member of this family of receptors, highly expressed on activated endothelial cells during angiogenesis, and associated with the tumor growth, invasion, and metastasis. [5][6][7] For the targeting of a v b 3 , Arg-Gly-Asp (RGD) derivatives labeled with various radioisotopes, such as, 125 I, 99m Tc, 18 F, 90 Y, 111 In, and 64 Cu, have been developed [8][9][10][11][12][13] and their biodistribution and dosimetry studies have been examined. 14,15 Recently, 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA)-based bifunctional chelating agent was employed to label an RGD peptide to 68 Ga. 16 The importance of 68 Ga for clinical positron emission tomography (PET) imaging has increased recently, because it has several inherent advantages for positron imaging in humans.…”