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 carcin oma previously treated with external-beam irradiation. Patients and me thods: Thirty patients with symptomatic endobronchial bronchogenic car cinoma 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 compre ssion. Furthermore, patients were also classified based on tumor locat ion: central (trachea or mainstem bronchi) and peripheral (lobar or se gmental bronchi). Patients underwent three treatments of 800 cGy intra luminal irradiation at 2-week intervals, with follow-up evaluation 4 w eeks later. We evaluated response in tumor extent based on bronchoscop ic and chest radiograph appearance, as well as symptoms with standardi zed scales. Results: Fifteen of 24 patients who underwent follow-up br onchoscopy had reductions in the degree of endobronchial obstruction. Seven of 24 patients had radiographic improvement in the extent of ate lectasis. Patients with both tumor appearances (endoluminal and submuc osal/extrinsic compression) had significant improvements following HDR -BT with regard to hemoptysis. Patients with submucosal disease also h ad improvement in cough. Patients with peripheral tumors had better ra tes of response for hemoptysis and cough than did those with central t umors. Conclusion: HDR-BT may result in symptomatic improvement in pat ients with bronchogenic carcinoma, whether characterized endoscopicall y as endoluminal projection or submucosal infiltration/extrinsic compr ession. Peripheral tumors have better rates of response than central t umors, possibly on the basis of less extensive disease.