Síntese, análise, purificação e biodistribuição em modelo animal do Radiofármaco 177Lu3+-dotatato para uso diagnóstico e terapêutico em tumores neuroendócrinos / SYNTHESIS, ANALYSIS, PURIFICATION AND BIODISTRIBUTION IN AN ANIMAL MODEL OF RADIOPHARMACEUTICAL 177Lu3+- DOTATATO FOR DIAGNOSTIC AND THERAPEUTIC USE IN NEUROENDOCRINE TUMORS

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The aim of this work was to propose rationalization in the synthesis, analysis and purification of radiopharmaceutical 177Lu3+-DOTATATO for diagnostic and therapeutic use in neuroendocrine tumors, as well as for evaluating biodistribution of this radiopharmaceutical in an animal-model. The complexation reaction for the synthesis of radiopharmaceutical was carried out in ammonium acetate buffer 0.5 M, pH 7.0, for 30 minutes at 95 oC. The radiochemical purity was >95%, according to analysis by chromatography in ITLC-SG, when using the sodium citrate buffer 0,1 M, pH 5.0, as the mobile phase. The molar-limit ratio 177Lu3+: DOTATATO, used in the synthesis of radiopharmaceutical 177Lu3+-DOTATATO, in ammonium acetate buffer 0.5 M, pH 7.0, for 30 minutes at 95 oC, was dependent on the specific activity and origin of the radioisotope, this being 1:3.5 (370 MBq : 2.6 mg) for that from the Oak Ridge National Laboratory/U.S.A., and 1:16 (370 MBq : 11.8 mg) for that from Nuclear Analytical and Medical Services/Holland, when considering a decay of five days from the production date of the radioisotopes. This rationalization in the synthesis of radiopharmaceutical 177Lu3+-DOTATATO permits high economy in production costs. Chemical studies on the synthesis of radiopharmaceuticals also placed in evidence the interference of 177Hf4+, the decay product of 177Lu3+, as the 177Lu3+ competitor for DOTATATO. Radiopharmaceutical preparation proved to be stable during 24 hours, at an activity rate of 2775 MBq, with the addition of 0.6 mg/mL of gentisic acid and when kept in dry ice. In biodistribution studies on Swiss and Nude mice, the specificity of radiopharmaceutical for somatostatin positive-receptor tissues, such as the pancreas, stomach, lungs, adrenal glands, kidneys and the cell tumor AR42J was demonstrated. Key words: synthesis, complexation, radiopharmaceutical, 177Lu3+-DOTATATO, neuroendocrine tumors

ASSUNTO(S)

tumor neuroendócrino tumor neuroendócrino radiofármaco síntese 177lu-dotatato síntese reação de complexação 177lu-dotatato radiofármaco reação de complexação

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