RT Journal Article SR Electronic T1 Anti-1-Amino-3-18F-Fluorocyclobutane-1-Carboxylic Acid: Physiologic Uptake Patterns, Incidental Findings, and Variants That May Simulate Disease JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1986 OP 1992 DO 10.2967/jnumed.114.143628 VO 55 IS 12 A1 David M. Schuster A1 Cristina Nanni A1 Stefano Fanti A1 Shuntaro Oka A1 Hiroyuki Okudaira A1 Yusuke Inoue A1 Jens Sörensen A1 Rikard Owenius A1 Peter Choyke A1 Baris Turkbey A1 Trond V. Bogsrud A1 Tore Bach-Gansmo A1 Raghuveer K. Halkar A1 Jonathon A. Nye A1 Oluwaseun A. Odewole A1 Bital Savir-Baruch A1 Mark M. Goodman YR 2014 UL http://jnm.snmjournals.org/content/55/12/1986.abstract AB Anti-1-amino-3-18F-fluorocyclobutane-1-carboxylic acid (18F-FACBC) is a synthetic amino acid analog PET radiotracer undergoing clinical trials for the evaluation of prostate and other cancers. We aimed to describe common physiologic uptake patterns, incidental findings, and variants in patients who had undergone 18F-FACBC PET. Methods: Sixteen clinical trials involving 611 18F-FACBC studies from 6 centers, which included dosimetry studies on 12 healthy volunteers, were reviewed. Qualitative observations of common physiologic patterns, incidental uptake, and variants that could simulate disease were recorded and compared with similar observations in studies of the healthy volunteers. Quantitative analysis of select data and review of prior published reports and observations were also made. Results: The liver and pancreas demonstrated the most intense uptake. Moderate salivary and pituitary uptake and variable mild to moderate bowel activity were commonly visualized. Moderate bone marrow and mild muscle activity were present on early images, with marrow activity decreasing and muscle activity increasing with time. Brain and lungs demonstrated activity less than blood pool. Though 18F-FACBC exhibited little renal excretion or bladder uptake during the clinically useful early imaging time window, mild to moderate activity might accumulate in the bladder and interfere with evaluation of adjacent prostate bed and seminal vesicles in 5%–10% of patients. Uptake might also occur from benign processes such as infection, inflammation, prostatic hyperplasia, and metabolically active benign bone lesions such as osteoid osteoma. Conclusion: Common physiologic uptake patterns were similar to those noted in healthy volunteers. The activity in organs followed the presence of amino acid transport and metabolism described with other amino acid–based PET radiotracers. As with other PET radiotracers such as 18F-FDG, focal nonphysiologic uptake may represent incidental malignancy. Uptake due to benign etiologies distinct from physiologic background also occurred and could lead to misinterpretations if the reader is unaware of them.