Fluorine-18 labeled amino acids for tumor PET/CT imaging

// Yiqiang Qi 1, 2, * , Xiaohui Liu 1, 2, * , Jun Li 4 , Huiqian Yao 5 and Shuanghu Yuan 2, 3 1 School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Jinan, Shandong, China 2 Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong Cancer Hospital affiliated to Shandong University, Jinan, Shandong, China 3 Shandong Academy of Medical Sciences, Jinan, Shandong, China 4 Department of Thoracic Surgery, Shandong Provincial Hospital, Jinan, Shandong, China 5 Department of Surgery, Juye Coalfield Central Hospital, Heze, Shandong, China * Authors contributed equally to this work Correspondence to: Shuanghu Yuan, email: yuanshuanghu@sina.com Keywords: Fluorine-18 labeled amino acids, positron emission tomography/computed tomography (PET/CT), tumor metabolism, molecular imaging Received: May 25, 2017      Accepted: July 25, 2017      Published: August 04, 2017 ABSTRACT Tumor glucose metabolism and amino acid metabolism are usually enhanced, 18 F-FDG for tumor glucose metabolism PET imaging has been clinically well known, but tumor amino acid metabolism PET imaging is not clinically familiar. Radiolabeled amino acids (AAs) are an important class of PET/CT tracers that target the upregulated amino acid transporters to show elevated amino acid metabolism in tumor cells. Radiolabeled amino acids were observed to have high uptake in tumor cells but low in normal tissues and inflammatory tissues. The radionuclides used in labeling amino acids include 15 O, 13 N, 11 C, 123 I, 18 F and 68 Ga, among which the most commonly used is 18 F [ 1 ]. Available data support the use of certain 18 F-labeled AAs for PET/CT imaging of gliomas, neuroendocrine tumors, prostate cancer and breast cancer [ 2 , 3 ]. With the progress of the method of 18 F labeling AAs [ 4 – 6 ], 18 F-labeled AAs are well established for tumor PET/CT imaging. This review focuses on the current status of key clinical applications of 18F-labeled AAs in tumor PET/CT imaging.