No-carrier-added, F-18-labelling of a cholesterol derivative, used in detection of adrenal malignancies

[F-18]Cholesteryl 4-(fluoromethyl)benzoate 6b was prepared from 3-cholester yl [(4-nitrobenzenesulfonyl)oxymethyl]benzoate in one step using K+-Kryptof ix 2.2.2, as counter ion and acetonitrile as the solvent at 40-60 degreesC. The product was isolated by HPLC in 75% (decay corrected) radiochemical yi eld with a radiochemical purity of more than 90% in 30 min (specific radioa ctivity 2000-2500 Ci/mmol). Biodistribution studies in mice showed that a h igh target/non-target ratio of radioactivity was obtained in adrenal and ov aries. Copyright (C) 2001 John Wiley & Sons, Ltd.