Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 1 de 1
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Ano de publicação
Tipo de documento
Intervalo de ano de publicação
1.
J Nucl Med ; 58(3): 432-437, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28082433

RESUMO

Radiolabeling of the prostate-specific membrane antigen (PSMA) inhibitor Glu-NH-CO-NH-Lys(Ahx) using the 68Ga chelator HBED-CC (PSMAHBED) allows imaging of prostate cancer lesions because of high expression of PSMA in prostate carcinoma cells and in bone metastases and lymph nodes related to the disease. The aim of this work was to optimize labeling of 68Ga-PSMAHBED using the efficient cation-exchange postprocessing of 68Ga as well as the development of a thin-layer chromatography (TLC)-based quality control system. Methods: Labeling was optimized for online ethanol-postprocessed 68Ga eluate investigating various parameters, such as buffer molarity (0.1-1 M), temperature (25°C-90°C), tracer amount (0.11-0.74 nmol), and labeling time. In addition, purification of the crude product was tested. For radio-TLC quality control, various mobile phases were analyzed using silica gel 60 plates and the results were validated using high-performance liquid chromatography. The most superior mobile phases were also applied on instant thin-layer chromatography (ITLC) silica gel plates. Results: Using optimized conditions, labeling yields of more than 95% were obtained within 10 min when ethanol-based postprocessing was applied using PSMAHBED amounts as low as 0.1 nmol. A higher precursor concentration (0.7 nmol) further increased labeling and quantitative yields to more than 98% within 5 min. In clinical routine, patient batches (>200 applications) with radiochemical purity greater than 98% and specific activities of 326 ± 20 MBq/nmol are obtained reproducibly. When TLC quality control was performed on silica gel 60 plates, 4 mobile phases with suitable separation properties and complementary Rf values were identified. Two systems showed equivalent separation on ITLC silica gel plates, with ITLC analysis finished within 5 min, in contrast to 20 min for the TLC system. Labeling of PSMAHBED was optimized for cation-exchange postprocessing methods, ensuring almost quantitative labeling and high nuclide purity of final 68Ga-PSMAHBED, making subsequent purification steps unnecessary. Conclusion: The new radio-TLC method allows quality control in a short time using a fast, reliable, low-cost method with little equipment complexity. Using this approach, the synthesis is easily adopted by automated synthesis modules.


Assuntos
Antígenos de Superfície/química , Contaminação de Medicamentos/prevenção & controle , Radioisótopos de Gálio/química , Glutamato Carboxipeptidase II/química , Marcação por Isótopo/métodos , Compostos Organometálicos/síntese química , Compostos Radiofarmacêuticos/síntese química , Ácido Edético/análogos & derivados , Isótopos de Gálio , Radioisótopos de Gálio/análise , Radioisótopos de Gálio/normas , Alemanha , Glutamato Carboxipeptidase II/normas , Marcação por Isótopo/normas , Oligopeptídeos , Compostos Organometálicos/análise , Compostos Organometálicos/normas , Controle de Qualidade , Geradores de Radionuclídeos/normas , Compostos Radiofarmacêuticos/análise , Compostos Radiofarmacêuticos/normas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA