Intracoronary radionuclide therapy with liquid 188Re-filled balloons;radiopharmaceutical and dosimetric studies

摘要

The present study had the purpose of optimizing the risk/benefit relationship during a procedure ofrnbrachytherapy with 188Re associated to angioplasty. The possibility of balloon rupture exists, with the passage ofrnthe radioactive solution towards the patient bloodstream. In order to increase the security during the treatmentrnthe evaluation of different agents such as 188Re-DTPA, 188Re-Citrate and 188Re-EC vs 188ReO4 – (as the standardrnagent) was performed. Labelling procedures were optimized considering pH, temperature, reaction time andrncarrier addition. Dosimetric studies using Mirdose 3, after iv injection to Wistar rats of the threernradiopharmaceuticals were performed. Biodistrubion at 1 and 3 hrs. post-administration and dose estimationrnshowed no difference between all the radiopharmaceuticals, presenting low uptake in thyroid and stomach, andrnfaster renal elimination than 188ReO4 –, with smaller residence times in all the organs. As the preparation ofrn188Re-Citrate and 188Re-EC required less strong conditions than 188Re-DTPA, one of these radiopharmaceuticalsrncould be selected to improve the security of the procedure. Furthermore, this study aimed to evaluate a numberrnof safety requirements in order to estimate radiation dose delivered to operating personnel. All radiationrnexposure rates measured in this study were significantly lower than those reported for brachytherapy performedrnwith 192Ir.