A combination therapy of photodynamic therapy (PDT) and airway stent placement using a transparent silicone stent
The aim of this study was to evaluate the feasibility of a combination therapy of photodynamic therapy (PDT) and airway stent placement using a transparent silicone stent (gold studded stent [GSS]). Laser irradiation (664 nm, continuous wave) was performed through the GSS using a straight and cylindrical fiber 1.0 cm away from a power meter. There are two types of GSS: the TD type for the trachea and the BD type for the bronchus. Laser outputs were set to 150 mW, 180 mW, 210 mW, 240 mW, 270 mW, and 300 mW. The laser powers passing through the both types of GSS were measured three times for each outputs and the averages were calculated. Based on the results, animal experiment was performed using two female pigs. Under general anesthesia, a GSS (BD type) was inserted into trachea of pigs, and PDT using NPe6 as a photosensitizer was performed by 100 J/cm2 laser irradiation on parts of the trachea with and without a GSS. Immediately after and 1 week after PDT, pig tracheas were harvested and histological analysis was performed. Histological analysis of areas with or without the stent showed edematous changes between the cartilage and submucosal layer immediately after PDT, and necrotic changes 1 week later. The effectiveness of NPe6-PDT for pigs’ trachea covered by the stent was same as trachea without the stent. The use of a GSS may enable PDT to be effective even in the area covered by the stent.
KeywordsPhotodynamic therapy Stent placement Lung cancer Airway obstruction
This study was supported by a Grant-in-Aid for Young Scientists (B) from The Ministry of Education, Culture, Sports, Science, and Technology (KAKENHI no. 21791333).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving animals were in accordance with the ethical standards of the institution or practice at which the studies were conducted. The study was performed with approval of the animal experiment ethics committee of IVTeC Co., Ltd. (Experiment number: M-10-015).
This article does not contain any studies with human participants performed by any of the authors.
- 4.Simoff MJ, Lally B, Slade MG, Goldberg WG, Lee P, Michaud GC, Wahidi MM, Chawla M (2013) Symptom management in patients with lung cancer: diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest 143:e455S–e497SCrossRefPubMedGoogle Scholar
- 11.Kato H, Furukawa K, Sato M, Okunaka T, Kusunoki Y, Kawahara M, Fukuoka M, Miyazawa T, Yana T, Matsui K, Shiraishi T, Horinouchi H (2003) Phase II clinical study of photodynamic therapy using mono-L-aspartyl chlorin e6 and diode laser for early superficial squamous cell carcinoma of the lung. Lung Cancer 42:103–111CrossRefPubMedPubMedCentralGoogle Scholar
- 12.Usuda J, Ichinose S, Ishizumi T, Hayashi H, Ohtani K, Maehara S, Ono S, Honda H, Kajiwara N, Uchida O, Tsutsui H, Ohira T, Kato H, Ikeda N (2010) Outcome of photodynamic therapy using NPe6 for bronchogenic carcinomas in central airways >1.0 cm in diameter. Clin Cancer Res 16:2198–2204CrossRefPubMedGoogle Scholar
- 14.Wisnivesky JP, Yung RC, Mathur PN, Zulueta JJ (2013) Diagnosis and treatment of bronchial intraepithelial neoplasia and early lung cancer of the central airways: diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest 143:e263S–e277SCrossRefPubMedGoogle Scholar