Local determinants of response to endobronchial high dose rate brachytherapy in bronchogenic carcinoma

Study objective: We evaluated bronchoscopic tumor appearance and tumor location as determinants of response to high-dose rate brachytherapy (HDR-BT) in patients with symptomatic unresectable bronchogenic carcinoma previously treated with external-beam irradiation. Patients and methods: Thirty patients with symptomatic endobronchial bronchogenic carcinoma who had previously completed external irradiation were divided into two groups based on whether the initial bronchoscopic appearance showed an endoluminal mass or submucosal infiltration/extrinsic compression. Furthermore, patients were also classified based on tumor location: central (trachea or mainstem bronchi) and peripheral (lobar or segmental bronchi). Patients underwent three treatments of 800 cGy intraluminal irradiation at 2-week intervals, with follow-up evaluation 4 weeks later. We evaluated response in tumor extent based on bronchoscopic and chest radiograph appearance, as well as symptoms with standardized scales. Results: Fifteen of 24 patients who underwent follow-up bronchoscopy had reductions in the degree of endobronchial obstruction. Seven of 24 patients had radiographic improvement in the extent of atelectasis. Patients with both tumor appearances (endoluminal and submucosal/extrinsic compression) had significant improvements following HDR-BT with regard to hemoptysis. Patients with submucosal disease also had improvement in cough. Patients with peripheral tumors had better rates of response for hemoptysis and cough than did those with central tumors. Conclusion: HDR-BT may result in symptomatic improvement in patients with bronchogenic carcinoma, whether characterized endoscopically as endoluminal projection or submucosal infiltration/extrinsic compression. Peripheral tumors have better rates of response than central tumors, possibly on the basis of less extensive disease.