PT - JOURNAL ARTICLE AU - Grant Rigney AU - Cyrus Ayubcha AU - Mona-Elisabeth Revheim AU - Thomas Werner AU - Abass Alavi TI - <strong>A Critical Assessment of PET Radiotracers in the Imaging of Astrocytic Tumors</strong> DP - 2022 Jun 01 TA - Journal of Nuclear Medicine PG - 2643--2643 VI - 63 IP - supplement 2 4099 - http://jnm.snmjournals.org/content/63/supplement_2/2643.short 4100 - http://jnm.snmjournals.org/content/63/supplement_2/2643.full SO - J Nucl Med2022 Jun 01; 63 AB - 2643 Introduction: Advances in our understanding of glial cell biology have advanced our ability to target glial tumors with multiple imaging modalities, including positron emission tomography (PET). To date, however, significant debate exists on which PET radiotracers are the most efficacious for the diagnosis and evaluation of astrocytic tumors. The aim of this study is to review existing literature on the use of PET imaging tracers in the diagnosis and management of astrocytic tumors.Methods: PubMed, Google Scholar, and Web of Science were queried for primary literature examining the use of any PET ligand in the diagnosis or management of astrocytoma tumors. Searches were performed with the following terms: “positron emission tomography”, “PET”, “PET ligand”, “glioma”, “glial tumor”, “astrocytoma”, "astrocytic", “diagnosis”, and “management”. Studies not reporting either a sensitivity, specificity, or overall accuracy of tracers were not included.Results: This search revealed substantial variability amongst existing literature about which PET radiotracer offers the best capabilities for diagnosing and managing astrocytic tumors in vivo. However, several promising radiotracers for the diagnosis and management of astrocytic tumors did emerge and deserve further exploration. Current RANO and SNMMI procedure standards for imaging of glioma with PET include the use of 11C-Methionine (MET), 18F-fluoroethyltyrosine (FET), and 18F-DOPA together. In addition to those mentioned above, a number of other radiotracers have been trialed for astrocytic tumors and include 18F-fluciclovine (18F-FACBC), 13N-ammonia (13N-NH3), 11C-choline (11C-CHO), 18F-fluorocholine (18F-FCH ), 11C-MeAIB, 18F/68Ga-prostate specific membrane antigen (18F/68Ga-PSMA), which is not solely specific for the prostate. Of note, 11C-MET PET-CT imaging has been shown to be of comparable efficacy to 18F-FDG in detecting and delineating low-grade gliomas (astrocytic and other glial tumors) from residual or recurrent lesions in some studies, although 18F-FDG-PET is known to be more efficacious across a wider range of tumors. Case reports have also demonstrated proof-of-concept for the ability of 18F-FDOPA PET-CT to detect recurrent astrocytoma after 18F-FDG PET-CT failed to detect recurrent tumor. 18F-Cho PET and MR imaging in conjunction has been shown to be effective for measuring morphologic and metabolic changes during therapy for astrocytic tumors in pediatric populations.Conclusions: Current clinical practice guidelines highlight the use of PET/MRI for determining the grade, treatment, and prognosis of primary gliomas. FDG-PET still offers the best validated capability to discriminate between tumor and healthy background tissue, and future studies are needed to elucidate the true clinical value of newer radiotracers that have been trialed for astrocytic tumors in a limited setting. Some radiotracers appear to be better equipped to characterize low-grade astrocytic tumors, however, additional prospective and comparative studies are needed to validate the populations that serve to benefit most from PET imaging of astrocytic tumors.