External beam radiation therapy for tracheobronchial amyloidosis

Background: Tracheobronchial amyloidosis is a rare form of primary amyloidosis. There have been no regimens for treatment of this disease that have proven to be effective. There have been case reports of external beam radiation therapy (EBRT) providing marked improvement in symptoms and the appearance of lesions. We report a series of seven consecutive patients who were treated with EBRT. Methods: All patients with tracheobronchial. amyloidosis were identified who had received EBRT at Mayo Clinic, Rochester, MN. A retrospective chart review was performed. Data were collected including symptoms, method of diagnosis, treatments, result of treatments, and side effects. Results: All patients received 20 Gy of radiation in 10 fractions. All patients had a favorable response to treatment ranging from symptom relief to a decrease in the frequency of pulmonary infections and objective improvement in pulmonary function. The time to subjective improvement ranged from 1 month to 1 year from the completion of EBRT. Grade 1 esophagitis developed in four patients, and grade 2 esophagitis developed in one patient. Grade 2 pneumonitis that resolved after 10 days of treatment with antibiotics and corticosteroids developed in one patient. FEV1 was the most consistently used method of objective follow-up, and three of seven patients showed improvement. Follow-up ranged from 10 to 69 months (median, 40 months). The recurrence of asymptomatic endobronchial narrowing requiring no additional treatment was noted on bronchoscopy in one patient, after 17 months. Conclusions: Tracheobronchial amyloidosis has been difficult to treat due to the limitations of treatment, recurrence, and complications. EBRT appears to be safe and can provide symptomatic as well as objective improvement.