title: A Novel Self-Expandable, Radioactive Airway Stent Loaded with125I Seeds: A Feasibility and Safety Study in Healthy Beagle Dog.
abstract: OBJECTIVE
  Airway stent placement is an effective treatment for the immediate palliation of malignant airway obstruction. However, restenosis caused by tumor ingrowth and/or overgrowth after stenting is common. The purpose of this study was to investigate the feasibility and safety of a novel self-expandable stent loaded with125I seeds in healthy beagle dog.
  
  
  METHODS
  Under fluoroscopic guidance, forty-eight self-expandable airway stents loaded with125I seeds were perorally placed in the main trachea of 48 healthy beagle dogs, who were randomly divided into four groups (Group A: 0.3 mCi; Group B: 0.6 mCi; Group C: 0.9 mCi; Control group: 0 mCi). The estimated radiation dose was calculated using the isotropic point source approximation. Radiological follow-up examinations and histopathological examinations of stented tracheal segments and their adjacent organs and tissues were performed at 2, 4, 8, and 16 weeks following the stenting.
  
  
  RESULTS
  All stents were successfully deployed in the targeted tracheal segment in the beagle dogs without procedure-related complications. Tracheal stenosis became severe gradually in all the four groups, which was not associated with the radioactivity of125I seeds (p > 0.05). The tracheal injury scores increased along with the higher dose of radioactive seeds which reached peak at 8 weeks and then turned back slightly at 16 weeks. The adjacent tissue did not show pathohistological changes under microscope, while mild and reversible ultrastructure changes were showed under electronic microscope.
  
  
  CONCLUSIONS
  This study demonstrates that it is feasible and safe to insert this novel self-expandable airway stent loaded with125I seeds in healthy beagle dog.
authors.affiliation: Center of Interventional Radiology & Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, 210009, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Center of Interventional Radiology & Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, 210009, China.
authors.forename: Jin-He
authors.initials: JH
authors.lastname: Guo
authors.affiliation: Center of Interventional Radiology & Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, 210009, China.
authors.forename: Guang-Yu
authors.initials: GY
authors.lastname: Zhu
authors.affiliation: Center of Interventional Radiology & Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, 210009, China.
authors.forename: Hai-Dong
authors.initials: HD
authors.lastname: Zhu
authors.affiliation: Center of Interventional Radiology & Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, 210009, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.affiliation: Center of Interventional Radiology & Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, 210009, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Lu
authors.affiliation: Center of Interventional Radiology & Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, 210009, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Center of Interventional Radiology & Vascular Surgery, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, 210009, China. gjteng@vip.sina.com.
authors.forename: Gao-Jun
authors.initials: GJ
authors.lastname: Teng
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D004307:Dose-Response Relationship, Radiation; D005240:Feasibility Studies; D005260:Female; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D010166:Palliative Care; D015607:Stents; D014132:Trachea / Q000473:pathology / Q000528:radiation effects; D014135:Tracheal Stenosis / Q000473:pathology / Q000532:radiotherapy*
chemical_list: D007457:Iodine Radioisotopes
keywords: Intraluminal brachytherapy; Iodine-125; Irradiation; Stent; Trachea