ABSTRACT
Localized amyloidosis refers to the deposition of ß-sheets of insoluble protein into single organs. The bladder, eye, breast, skin or brain may be involved. In the lung, localized amyloid may occur as parenchymal nodules, diffuse alveolar disease, or submucosal deposits involving the larynx, subglottis, or tracheobronchial network. Tracheobronchial amyloidosis (TBA) is a rare disorder, representing 1.1% of patients referred to Boston University. Biopsy-proven TBA patients with progressive airflow obstruction by spirometry and airway narrowing by chest CT or bronchoscopy were treated with external beam radiation (EBRT) at Boston Medical Center. Low dose EBRT is well tolerated in patients with tracheobronchial amyloidosis, with mild and transient declines in gas diffusion being the most significant complication. EBRT appeared to prevent progressive amyloid deposition in localized airway disease for up to 44 months follow-up. Pulmonary function tests documented airflow preservation. Whether low dose EBRT induces subclinical lung injury remains unclear.
