Effect of Endobronchial Radiation Therapy on Malignant Bronchial Obstruction
With more than 150,000 cases every year, lung cancer represents today s major oncologic challenge. There are more than 120,000 deaths annuallyand most therapeutic approaches result in a high incidence of local failure that frequently manifests as malignant airway occlusion. According to one estimate, 20 to 30 percent of newly diagnosed lung malignant neoplasms will present with atelectasis and pneumonia due to endobronchial disease. Other estimates suggest that because of a high rate of local failure following conventional therapy, up to 50 percent of patients with lung cancer will eventually develop symptomatic endobronchial disease. Death from airway occlusion is often a painful process of slow asphyxiation, frequently complicated by obstructive pneumonia and hemoptysis. The majority of these patients have previously received high-dose radiation, and tissue tolerance concerns frequently preclude further external radiation. We report herein the results of our experience with endobronchial radiation therapy (EBRT) for malignant airway occlusion.
Materials and Methods
Between October 1986 and March 1989, 52 patients underwent 55 endobronchial procedures. The technical and dosimetric details have been published previously. Median age at presentation was 67 years with a male to female ratio of 42 to 10. Forty-six patients had primary lung malignant neoplasms and six had nonpulmonary tumors. Twenty-three patients had metastatic disease at implantation. Eleven patients had received prior chemotherapy and 31 had undergone external radiation prior to implantation. The mean time to endobronchial occlusion from completion of prior external radiation was 26.5 months with a range of two to 150 months. Twenty three patients had received what was deemed to be tolerance level radiation (>6,000 rad). Of the 55 implants, eight presented with Eastern Cooperative Oncology Group (ECOG)performance status (PS) 4, 14 with PS 3, 23 with PS 2, nine with 1э and one with PS 0. The most common symptoms, in decreasing order of frequency, were cough (52), dyspnea (51), pneumonia (23), hemoptysis (21), and chest pain (19). Of the 55 patients, 39 (71 percent) had at least three symptoms at presentation. Twelve patients underwent Nd:YAG laser excision of the tumor prior to EBRT. The median implant duration was 50 h, with a range from 11 to 115 h. The median dose at 1 and 2 cm from the center of the source was 4,700 and 2,000 rad, respectively.
Several parameters were analyzed to assess response. These included change in PS, symptom resolution by Radiation Therapy Oncology Group (RTOG) criteria,® percentage of lifetime rendered symptom improved or symptom free, roentgenographic reaeration, change in pulmonary function, and bronchoscope response.