Long-term clinical benefits of the low dose rate endobronchial irradiation of malignant airway obstructions.

Brachytherapy allows the delivery of higher radiation doses, possibly leading to improved locoregional tumor control and subsequent prolonged survival. The purpose of our study was to evaluate the long-term clinical survival in patients with malignant airway compromise treated with endobronchial brachytherapy and to estimate possible influence of other factors on survival and to review complications of the therapy. In a retrospective study 55 patients with malignant inoperable tracheobronchial lesions underwent 71 brachytherapy treatments with 137Cesium. Either MicroSelectron (N=56) or Selectron (N=15) were used. All except 4 patients received external radiation, 20 patients received chemotherapy, 37 patients received laser excision. Major symptomatic improvement was noted in 75% of patients. Substantial or complete relief of hemoptysis was achieved in 85%, of dyspnea in 65% and of cough in 68%. Response evaluation showed no complete response, partial response was achieved in 70.9% and the endoscopic finding was not changed, or recurrence of the tumor was found in 29.1%. A relatively small number of complications of the endobronchial brachytherapy occured. Significant bleeding was observed in 1 procedure and an inability to tolerate in 3 cases. In 2 cases, it was not possible to place an applicator due to extreme hypoxia. Bronchomediastinal fistula developed in 1 patient and tracheal stenosis in 1 patient. The overall incidence of complications was 15%. The median survival from establishing the diagnosis was 510 days. The median survival after the first brachytherapy treatment was 200 days. We compared the survival in the subgroups of patients in relation to TNM status, chemotherapy, laser debulking brachytherapy device used. The stage IIIA patients survived longer from diagnosis than IIIB patients but the difference was on the border of significance (p = 0.090). In the evaluation of chemotherapy, more patients survived 12 months from the diagnosis (p = 0.045) when treated by chemotherapy comparing to the patients treated without chemotherapy. However, this difference disappeared during the further development of the disease. In the Nd-YAG laser treatment, the patients treated by brachytherapy with the previous laser debulking survived significantly longer from the time of the first brachytherapy session (p = 0.005). No statistical difference was found in the survival of patients treated by either the Selectron or MicroSelectron device. The LDR endobronchial brachytherapy is a well tolerated, safe and effective technique for palliation of malignant airway occlusions. In our group of patients, the long-term survival was longer in IIIA stage comparing to the IIIB, in the group treated by the previous chemotherapy compared to the patients without chemotherapy and in the group with the Nd-YAG laser therapy, comparing to the group treated by the brachytherapy only. No difference of the brachytherapy device used was found.