Study Of Endotracheal ～(125)Ⅰ Radioactive Stent In Conine

To evaluate the feasibility and safety of endotracheal ¹²⁵I radioactive stent and to find out the relationship between original radioactivity and degree of radioactive injury to trachea of canine. Materials and methods:Titanium-shelled radioactive particles containing I were embeded into 6 nitinol stents. The total radioactivity of the stents were3. 9mCi (1. 44 ×10⁸Bq). 5.8mCi(2. 15 ×10⁸Bq), 7. 8mCi (2. 89 × 10⁸Bq) , 10. 2mCi (3. 77 × 10⁸Bq) , 11.9mCi(4. 40 × 10⁸Bq) , 13.1mCi (4. 85 × 10⁸Bq). The 6 radioactive stents were implanted into trachea of 6 canines, respectively. Before implantation, tracheal stenosis was formed by sugery. The implantations were accomplished with laryngoscope and X ray. Blood were also drawn for routine and immunoglobin test before implantation. During the following 120 days of feeding time (double half-life of ¹²⁵I) X-ray were regularly done to see whether or not there was transposition and the living behavior of the canines were also observed. All animals were killed 120 days later. Specimen of trachea and esophagus were obtained and were fixed with 10% formalin for HE coloration. Radioactive injury of trachea and esophagus were evaluated under miroscope. Blood routine and immunoglobin before and after implantation were compared. Results:All stents were successfully implanted into canines' trachea and no transposition of stent was found during four-month observation. Canines' life behavior seemed normal. Relationship curve of the degree of radioactive injury and radioactivity of stents were drawn. Blood routine test were all in normal scale before and after implantation. Statistic analysis of...