High Dose Rate brachytherapy to prevent recurrent benign hyperplasia in lung transplant bronchi: Theoretical and clinical considerations

Background: Significant anastomotic stenosis and malacia is reported to affect 7% to 15% of lung transplant recipients. Laser debridement, dilation and stenting can be used effectively to treat the majority of these patients. However, persistent, as well as reactive hyperplastic tissue reaction, will occur in some of these patients, requiring multiple bronchoscopic interventions. The experience of 2 patients who received intraluminal brachytherapy irradiation to prevent recurrence of hyperplastic tissue causing airway obstruction is reported. Both had failed multiple attempts of local control, including wall stent, laser ablation and balloon dilation. They suffered from shortness of breath and progressive decrease in quality of life because of airway obstruction. Methods: Two patients received intraluminal irradiation immediately following removal of severe post-lung transplant obstruction. Both patients' developed airway obstruction 3 to 4 months after left lung transplantation. High:Dose Rate (HDR) brachytherapy (Ir-192). Afterloader was used to treat Patient 1 on two occasions, Patient 2 required a single treatment. The radiation dose of 3Gy/fraction was calculated at 1 cm from the catheter for all applications. Results: Follow up for both patients included bronchoscopy at 3 weeks, 3 months and 6 months after radiation therapy. Follow up for Patient 1 is 7 months, and patient 2 is 6 months. Each patient had an initial complete response after radiation. There were no treatment-related complications, and both patients experienced significant improvement in respiratory function. Conclusions: Symptomatic benign airway obstruction:from hyperplastic tissue in the bronchus after lung transplantation can be successfully treated with intraluminal radiation therapy. Patients who develop recurrent benign granulation tissue after stent and laser therapy may be considered for this type of treatment.