Pages: 260-268

Authors: Djordje Ž. Petrović, Nadežda S. Nikolić, Dragana T. Stanković, and Divna Dj. Djokić

Abstract

Radiopharmaceuticals based on ⁹⁰Y are widely used in the treatment of malignant deseases. In order to meet the requirements for their future application, a ⁹⁰Sr/⁹⁰Y generator was developed and ⁹⁰Y eluted from this locally produced generator was used for the radiolabelling of the DOTA-conjugated somatostatin analog [DOTA⁰,Tyr³] octreotate and the preparation of [⁹⁰Y-DOTA⁰,Tyr³] octreotate (⁹⁰Y-DOTATATE) for peptide receptore radionuclide therapy.⁹⁰Sr/⁹⁰Y generator was based on the electrochemical separation of 90Y from ⁹⁰Sr in a two-cycle electrolysis procedure. Three electrode cells were used to perform both electrolyses. In both cycles, working electrodes were kept on constant potential. The pH of the solution was adjusted to 2.7 of the value before the electrolyses. The radionuclidic purity of the ⁹⁰Y solution was analysed by ITLC and extraction paper chromatography. The labelling of peptide (100µg DOTATATE) with ⁹⁰YCl₃ was performed at 95 °C for 30 minutes. Radiochemical purity was determined by HPLC and chromatographic separation, using a solid SepPak C-18 column. Results obtained confirmed the efficiency of our electrochemical separation technique and quality control methods for ⁹⁰Y. The achieved efficiency of the ⁹⁰Sr/⁹⁰Y generator above 96% of the theoretical value represents a good basis for the further development of this generator. The labelling of the DOTATATE with ⁹⁰Y exhibited a high efficiency, too: there was less than 1% of ⁹⁰Y³⁺ in the ⁹⁰Y-DOTATATE.

Key words: radionuclide therapy, ⁹⁰Y, ⁹⁰Sr/⁹⁰Y generator, radiolabelling, ⁹⁰Y-DOTATATE

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