A Functional Stent Encapsulating Radionuclide in Temperature-Memory Spiral Tubes for Malignant Stenosis of Esophageal...

Stent implantation is a commonly used palliative treatment for alleviating stenosis in advanced esophageal cancer. However, tissue proliferation induced by stent implantation and continuous tumor growth can easily lead to restenosis. Therefore, functional stents are required to relieve stenosis while inhibiting tissue proliferation and tumor growth, thereby extending the patency. Currently, no ideal functional stents are available. Here, iodine-125 (¹²⁵ I) nuclides are encapsulated into a nickel-titanium alloy (NiTi) tube to develop a novel temperature-memory spiral radionuclide stent (TSRS). It has the characteristics of temperature-memory, no cold regions at the end of the stent, and a uniform spatial dose distribution. Cell-viability experiments reveal that the TSRS can reduce the proliferation of fibroblasts and tumor cells. TSRS implantation is feasible and safe, has no significant systemic radiotoxicity, and can inhibit in-stent and edge stenosis caused by stent-induced tissue proliferation in healthy rabbits. Moreover, TSRS can improve malignant stenosis and luminal patency resulting from continuous tumor growth in a VX2 esophageal cancer model. As a functional stent, the TSRS combines the excellent properties of NiTi with brachytherapy of the ¹²⁵ I nuclide and will make significant contributions to the treatment of malignant esophageal stenosis.