Preparation of 32P radioactive covered metal stent: an experimental study in vitro

Objective: To optimize the preparation technique of 32P radioactive covered metal stent. Methods: The 32P radioactive material leakage rate in saline of polyvinyl alcohol membrane and polyurethane membrane was calculated respectively. The 32P radioactive material disposition homogeneity in different polyurethane membranes and in different portions of polyurethane membrane was determined separately. Polyurethane membrane homogeneity by drop-coating and dip-coating on metal stent was evaluated respectively. The results were statistically analyzed. Results: The 32P radioactive material leakage rate in saline of polyvinyl alcohol membrane was 90%, but the 32P radioactive material leakage rate of polyurethane membrane was very low. No significant difference in the 32P radioactive disposition homogeneity existed between different polyurethane membranes (Mann-Whitney Test, U = 10.0, P = 0.602 > 0.05), and the mean difference in different portion of polyurethane membrane was 11.76%. The polyurethane membrane on stent covered by dip-coating technique was homogeneous, but the membrane was not homogeneous,even with perforation,if covered by drop-coating technique. Conclusion: The polyurethane membrane on metallic stent which is covered by dip-coating technique can decrease the 32P radioactive material leakage in saline, and the distribution of the radioactive material in such a membrane is quite homogeneous. (authors)