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Non-Clinical Medicine - Physiology - Radiology and Medical Imaging

Human Biodistribution and Dosimetry of 11C-CUMI-101, an Agonist Radioligand for Serotonin-1A Receptors in Brain
Published: Tuesday, September 27, 2011
Author: Christina S. Hines et al.

by Christina S. Hines, Jeih-San Liow, Paolo Zanotti-Fregonara, Jussi Hirvonen, Cheryl Morse, Victor W. Pike, Robert B. Innis


Nine healthy volunteers were injected with 428±84 MBq (mean ± SD) 11C-CUMI-101 and then imaged with a PET-only device for two hours from head to mid-thigh. Eleven source organs (brain, heart, liver, pancreas, stomach, spleen, lungs, kidneys, lumbar spine L1-5, thyroid, and urinary bladder) were identified on whole body images and used to calculate radiation doses using the software program OLINDA/EXM 1.1. To confirm that we had correctly identified the pancreas, a tenth subject was imaged on a PET/CT device.


Brain had high uptake (~11% of injected activity (IA)) at 10 min. Although liver had the highest uptake (~35% IA at 120 min), excretion of this activity was not visible in gall bladder or intestine during the scanning session. Organs which received the highest doses (microSv/MBq) were pancreas (32.0), liver (18.4), and spleen (14.5). The effective dose of 11C-CUMI-101 was 5.3±0.5 microSv/MBq.


The peak brain uptake (~11% IA) of 11C-CUMI-101 is the highest among more than twenty 11C-labeled ligands reported in the literature and provides good counting statistics from relatively low injected activities. Similar to that of other 11C-labeled ligands for brain imaging, the effective dose of 11C-CUMI-101 is 5.3±0.5 microSv/MBq, a value that can now be used to estimate the radiation risks in future research studies.