A Metal Bare Stent With 125 Iodine （125I）Seeds for the Treatment of Malignant Central Airway Stenosis

Malignant central airway stenosis caused by primary or metastatic malignant tumor may lead to dyspnea even death of patients.With the rapid development of interventional pulmonology, bronchoscopic therapy has become the main treatment for malignant central airway stenosis. Metal stent implantation in airway can quickly relieve respiratory obstruction and improve quality of life.However, the tumor tissue can continue to grow into metal stent and obstruct airway again. This is the shortcoming of metal bare stents, which often need further treatment to keep airway open, including ablation, laser, cryotherapy, external radiotherapy or systemic anti-tumor drug therapy.Metal stent implantation combined with external radiotherapy can effectively reduce the incidence of airway restenosis.However, complications of external radiotherapy are high, including bone marrow suppression, radioactive pneumonia, radioactive esophagitis, myocardial injury and tracheoesophageal fistula, of which may cause serious consequences and even cause death of the patient.125I radioactive seeds have been one of the mature radioactive interventional therapy, which release X rays, and γ rays. Because of the short radioactive distance, 125I seeds can destruct tumor cells in tumor site and promote apoptosis and necrosis of tumor cells around the obstruction of the airway, meanwhile cause little damage to the surrounding normal tissues. Some studies showed that 125I seed implantation of lung tumor lesions achieved good short-term results.Therefore, the investigators hypothesize that 125I seeds fixed on the metal bare stent can not only improve the patient's breathing difficulties, but also play a role in killing tumor cells. At present, there have been reports of related clinical cases and monocentric control studies of malignant central airway stenosis treated with the implantation of metal stent with 125I seeds, but there is a lack of multicentric clinical studies with large samples.