Preclinical study investigating the potential of low-dose-rate brachytherapy with32P stents for the prevention of restenosis of paranasal neo-ostia.
Ostial restenosis is a common cause of failures in paranasal sinus surgery. The aim of the current study was to investigate the use of low-dose-rate brachytherapy to prevent neo-ostial restenosis in an animal model.



In 14 rabbits, maxillary neo-ostia were created and measured. One side each was stented with a regular silicone stent, the other side was either not stented (n = 7) or stented with a phosphorous-32 implanted stent depositing a low-dose radiation of 15 Gy (n = 7) within 1 week, after which all stents were removed. After a period of additional 12 weeks of recovery, the animals were sacrificed, the neo-ostia were again measured, and the areas and histopathologic changes compared in between the groups.



After 15-Gy stenting, the mean ostial areas were even slightly enlarged by 5.1% compared to the area at stent removal, whereas a significant reduction in area, indicating a process of restenosis, by 56.1% or 54.0% was seen in the control groups with no stent and normal stent, respectively. Furthermore, no indication for adverse histopathologic radiation effects was seen in the 15-Gy group.



Low-dose-rate brachytherapy with phosphorous-32 doped silicone stents showed promising results in the prevention of neo-ostium restenosis in this proof-of-concept study, indicating that further preclinical and clinical testing may be warranted.
Department of Otorhinolaryngology, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany.
Elmar
E
Oestreicher
Institute of Pathology, Ludwig Maximilian University, Munich, Germany.
Harald
H
Bartsch
Institute of Pathology, Ludwig Maximilian University, Munich, Germany.
Doris
D
Mayr
Department of Medical Physics, Ludwig Maximilian University, Garching, Germany.
Mario
M
Schubert
Department of Otorhinolaryngology, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany.
Barbara
B
Weber
Department of Radiotherapy and Radiation Oncology, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany.
Peter
P
Kneschaurek
Department of Medical Physics, Ludwig Maximilian University, Garching, Germany.
Walter
W
Assmann
Laser Research Laboratory, LIFE Centre, Klinikum der Universität München, Munich, Germany; Department of Urology, Klinikum der Universität München, Munich, Germany.
Ronald
R
Sroka
Laser Research Laboratory, LIFE Centre, Klinikum der Universität München, Munich, Germany; Department of Otorhinolaryngology, Klinikum der Universität München, Munich, Germany. Electronic address: christian.betz@med.uni-muenchen.de.
Christian Stephan
CS
Betz
D000818:Animals; D001918:Brachytherapy / Q000379:methods*; D003251:Constriction, Pathologic / Q000517:prevention & control*; D008443:Maxillary Sinus / Q000601:surgery*; D010254:Paranasal Sinus Diseases / Q000601:surgery*; D010761:Phosphorus Radioisotopes / Q000627:therapeutic use*; D011183:Postoperative Complications / Q000517:prevention & control*; D011817:Rabbits; D015607:Stents
D010761:Phosphorus Radioisotopes
Low-dose brachytherapy; Neo-ostium; Paranasal sinus; Phosphorous-32; Restenosis