Whole-Body Biodistribution and Radiation Dosimetry of 18F-GE067: A Radioligand for In Vivo Brain Amyloid Imaging

Abstract

We have characterized the biodistribution and dosimetry of ¹⁸F-3′-F-6-OH-BTA1 (¹⁸F-GE067), a newly developed radioligand to visualize and quantify amyloid burden, in healthy elderly human subjects. Methods: Six subjects (5 men and 1 woman; age range, 51–74 y) underwent dynamic whole-body PET/CT for 6 h after a bolus injection of ¹⁸F-GE067. Source organs were delineated on PET/CT. Individual organ doses and effective doses were determined. Results: No adverse events or clinically significant changes were observed. ¹⁸F-GE067 is excreted predominantly through the hepatobiliary system. The gallbladder, upper large intestine, and small intestine are the organs with the highest absorbed dose (average, 287, 173, and 155 μGy/MBq, respectively). The mean effective dose was 33.8 ± 3.4 μSv/MBq, a dose comparable to that of many other ¹⁸F-labeled radiopharmaceuticals. Conclusion: The estimated effective dose of ¹⁸F-GE067 for PET amyloid imaging was acceptable (class II-b defined by the World Health Organization), and relatively low variability between subjects was observed.