Radiopharmaceuticals for Positron Emission Tomography Imaging of Somatostatin Receptor Positive Tumors

Abstract

The targeting of somatostatin receptors in tumors has been a goal in cancer treatment and diagnosis since the 1980s. Over the past two decades, great strides have been made in the development of somatostatin analogs labeled with positron emitters for positron emission tomography (PET) imaging of somatostatin receptor positive tumors. In this review, the radionuclide production, radiochemistry, preclinical and clinical studies of somatostatin analogs labeled with several positron-emitting radionuclides are described. In the past 5 years, there have been clinical trials with ¹⁸F-, ⁶⁴Cu-, ⁶⁸Ga-, ⁸⁶Y- and ^110mIn-labeled somatostatin analogs. In addition, radiochemistry and preclinical studies have been performed with ⁷⁶Br and ⁶⁶Ga. The advantages of these positron-emitting somatostatin analogs include increased image resolution with PET compared with γ scintigraphy, improved quantification capabilities with PET, and the ability to use the positron emitters as companion isotopes to therapeutic radionuclides such as the ⁸⁶Y (PET)/⁹⁰Y (therapy) pair.