Rapid preparation method for technetium-99m bicisate

The method currently recommended for the preparation of technetium-99m bicisate (^99mTc-bicisate) requires a lenglhy 30-min incubation at room temperature. The purpose of thls study was to evaluate an alternative method to shorten the preparation time.^99mTc-bi-cisate was prepared with 3.7 GBq (100 mCi)^99mTc according to the manufacturer's instructions, except for the final incubation step, which was replaced with the microwave heating procedure. A standard thin-layer chromatography (TLC) method (i.e., Baker-Flex silica gel IB-F TLC plate with ethyl acetate as mobile phase) was used for the determination of the radiochemical purity (RCP) of^99mTc-bicisate. Our evaluation with different microwave heating processes (300 W with different heating times) demonstrated that as the microwave heating temperature was increased (i.e., 44°-71° C), an increased percentage of samples reached 95% within 5 min post preparation (n=58). The highest RCP value (i.e., 97.4%±0.5%,n=10) could be obtained immediately after an 8-s microwave heating time at 300 W (microwave temperature at 69° C), and an average RCP value of 96.4%±1.3% (n=90) was maintained throughout the 24-h evaluation period. However, the trend seemed to reverse at higher microwave temperatures (i.e., 76°-90° C), which reconfirmed our initial findings that overheating had no benefit for the preparation of^99mTc-bicisate. To ensure that temperature was the only determining factor, a hot water incubator sel at 69°C was used (n=6). Similar RCP results were achieved. In conclusion, the use of a microwave oven at a low heat cycle provides a rapid and efficient way to prepare^99mTc-bicisate.This work was presented at the 43rd Annual Meeting of the Society of Nuclear Medicine on 3 June 1996, and was published in abstract form (J Nucl Med 1996; 37: 142P–143P).