High dose-rate intraluminal irradiation in bronchogenic carcinoma: Technique and results
Patients who present with symptomatic airway obstruction often have limited therapeutic options. Intraluminal irradiation has been used in an attempt to obtain sustained palliation. Patients treated with high dose-rate endobronchial irradiation have shown good to excellent palliation of symptoms, as well as a high rate of local control; however, these results have not always been devoid of complications. Some recent reports have shown a high incidence of morbidity, including an excessive incidence of fatal pulmonary hemorrhage. In this series, we report on 80 high dose-rate endobronchial treatments in 32 patients who were treated with remote afterloading endobronchial irradiation. All patients had endoscopic and histologic proof of tumor. Patients were divided into two groups. Group 1 consisted of 17 patients who were treated with endobronchial brachytherapy as a boost to primary external-beam irradiation. The remaining 15 patients comprised group 2 and were treated for endobronchial recurrence after prior irradiation with an external beam (main dose, 5,000 cGy). The endobronchial irradiation treatments were delivered using a high dose-rate remote afterloader. The standard dose per fraction was 500 cGy prescribed at a distance of 1 cm from the central axis of the catheter for a median of 3 fractions at weekly intervals. Treatment length averaged 5 cm; the median total dose was 1,500 cGy. The median follow-up for the entire group was 9.3 months, with a range of 6 to 24 months. Symptomatic improvement was attained in 15 of 15 patients presenting with hemoptysis, in 6 of 7 of those with cough, and in 10 of 10 who presented with dyspnea. In ten patients, follow-up endoscopy was performed, which revealed a pathologic complete response (by negative results on biopsies). At 6 months past the last brachytherapy, clinical and radiographic local control was obtained in 15/17 (88 percent) of the patients in group 1 and in 70 percent of the patients in group 2. All patients tolerated treatment well, without any acute or late complications, and there were no instances of fistula formation or fatal pulmonary hemorrhage. There was no association between the location of recurrence and complications. Fractionation, dose per fraction, and total combined dose appear to be important parameters in reducing complications.