Estudos de técnicas de concentração da  atividade de 99mTc eluído de geradores de 99Mo/99mTc tipo gel

Abstract

On average 80% of the radiopharmaceuticals used in Nuclear Medicine are labeled with 99m Tc due to its physical properties and easy attainment through of 99 Mo/ 99m Tc generators. The Directory of Radiopharmacy (DIRF) of IPEN-CNEN/SP developed a gel type chromatographic generator of MoZr with 99 Mo produced by 98 Mo(n,γ) 99 Mo reaction that occurs at the IEA-R1 Nuclear Reactor. The gel is composed of zirconium molibdate with elution volume of 12 mL with an activity of 11100 MBq (300 mCi) producing a radioactive concentration of 925 MBq (25 mCi)/mL. The fission generator gives a higher radioactive concentration around 1850 MBq (50 mCi)/mL. The aim of this work is to study a system of post-elution concentration of 99m Tc for the attainment of a high enough radioactive concentration to meet the demands of the market, with a proved quality. Two types of systems of post-elution concentration were developed: the single and the tandem. The most appropriate system for the gel generator of 99 Mo/ 99m Tc, being at the same time sterile and vacuum automated, was the tandem system using Dionex 2.5 cc/QMA cartridges. The gel generator is eluted with 10 mL of solution of 0.1% NaCl and the pertechnetate anion is retained in the QMA cartridge and further eluted with 4 mL of saline. The process takes no more than 30 minutes. The elution efficiency of the system of concentration was 90 %. At the beginning of 2009 a global crisis in the supply of 99 Mo took place making it necessary the development of alternative technologies for the production of 99 Mo/ 99m Tc generators using fission produced 99 Mo and the development of an appropriate method to extend the useful life of this generator. The results of this study showed that the same system developed for the post-concentration of the gel generator can be employed for the fission generator, using the tandem system, giving a concentration factor of 3 for the elution of 99m Tc. LISTA DE FIGURAS FIGURA 1 Curva de decaimento e crescimento do gerador de 99 Mo/ 99m Tc

Estudo de metodologias de controle de qualidade do Mo-99 utilizado no preparo de geradores de Mo-99/Tc-99m

“…O detector de germânio hiperpuro (HPGe) é um tipo de detector semicondutor que pode ser utilizado em espectrometria gama. Consiste em um cristal de germânio de alta pureza e apresenta boa resolução, sendo utilizado para medidas qualitativas e quantitativas de raios-X e raios gama (NIETO, 1998;SUZUKI, 2009 Os limites de detecção (LD) e os limites de quantificação (LQ) para as energias gama de interesse também foram calculados para cada uma das seis prateleiras do equipamento, para os tempos de contagem de 10 min, 30 min e 1 h, para fonte pontual, segundo as Eq. 5 e 6 (BRAMBILLA, 2013).…”