RADIATION BRONCHITIS AND STENOSIS SECONDARY TO HIGH-DOSE RATE ENDOBRONCHIAL IRRADIATION

Purpose: To describe a new clinical entity observed in follow-up bronchoscopies in patients who were treated with high dose rate and medium dose rate remote afterloading brachytherapy of the tracheobronchial tree. Methods and Materials: Patients treated by protocol with medium dose rate, 47 patients receiving 1000 cGY at a 5 mm de th times three fractions, high dose rate 144 patients receiving 1000 cGy at a 10 mm depth for three fractions and high dose rate 151 patients receiving 750 cGy at a 10 mm depth for three fractions followed by bronchoscopy. Results: Incidence of this entity was 9% for the first group, 12% for the second, and 13% for the third group. Reactions were grade 1 consisting of mild mucosal inflammatory response with a partial whitish circumferential membrane in an asymptomatic patient; grade 2, thicker complete white circumferential membrane with cough and/or obstructive problems requiring intervention; grade 3, severe inflammatory response with marked membranous exudate and mild fibrotic reaction; and grade 4 a predominant fibrotic reaction with progressive stenosis. Variables associated with a slightly increased incidence of radiation bronchitis and stenosis included: large cell carcinoma histology, curative intent, prior laser photoresection, and/or concurrent external radiation. Survival was the strongest predictor of the reaction. Conclusion: Radiation bronchitis and stenosis is a new clinical entity that must be identified in the bronchial brachytherapy patients and treated appropriately.