A comprehensive study on the blockage of thyroid and gastric uptakes of ¹⁸⁸re-perrhenate in endovascular irradiation using liquid-filled balloon to prevent restenosis

¹⁸⁸Re-perrhenate has been reported effective in preventing restenosis after percutaneous transluminal coronary angioplasty. However, if the balloon ruptures, ¹⁸⁸Re-perrhenate is released into the circulation, causing high radiation dosing to the thyroid and stomach. In this study, we evaluated the effects of perchlorate or iodide given at different times and in different ways for blocking the uptake of ¹⁸⁸Re-perrhenate in the thyroid glands and the stomach to find the best method to apply clinically to reduce the radiation dose in case of balloon rupture. Sodium perchlorate, sodium iodide, or potassium iodide was given orally or intravenously to rats before, during, and after the injection of ¹⁸⁸Re-perrhenate. The rats were sacrificed and we calculated the concentration of ¹⁸⁸Re-perrhenate in various organs to evaluate the preblocking, mixed formula, and postblocking effects of perchlorate or iodide. Our data showed that the preblocking method effectively reduced the uptake of ¹⁸⁸Re-perrhenate in both the thyroid and the stomach. The mixed formula method also demonstrated good blocking effect. The postblocking method showed obvious depression of thyroid uptake of perrhenate but its blocking effect on the stomach was not satisfactory. Copyright (C) 2000 Elsevier Science Inc.