Positron Emission Tomography Imaging of Macrophages in Cancer
Departments of Chemistry and Radiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
Author to whom correspondence should be addressed.
Academic Editors: Tadashi Watabe and Frederik Lars Giesel
Received: 22 March 2021 / Revised: 13 April 2021 / Accepted: 13 April 2021 / Published: 16 April 2021
Tumor-associated macrophages (TAMs) play numerous roles in cancer biology and are an important component of the relationship between immune system response and tumor progression. Several new immunotherapy techniques have been developed that target TAMs and are under investigation in both clinical and preclinical settings. Despite this surge of new immunotherapy techniques, a means to specifically and quantifiably measure the presence of TAMs to ensure the viability of these therapies, has yet to be widely investigated. The development of molecular imaging agents that target TAMs provides a path to noninvasively gain valuable insight into the molecular and functional characteristics of the tumor microenvironment and how the immune response facilitates the progression of cancer or therapy response. This article reviews published preclinical and clinical research in the imaging of TAMs through Positron Emission Tomography (PET).