Endobronchial radiation therapy for obstructing malignancies: ten years' experience with iridium-192 high-dose radiation brachytherapy afterloading technique in 365 patients.

From 1983 to 1993, 365 patients with obstructing endobronchial malignancies were treated by endobronchial high-dose radiation (HDR) iridium-192 afterloading. In 346 patients, the objective was palliation, and in 19, the objective was curative. A dose of 5 Gy at 10 mm from the source axis was administered on three (palliation) and four (cure) occasions, at intervals of 14 days. The majority of patients were treated after exhaustion of external beam radiation therapy (EBRT), often in conjunction with other interventional bronchologic modalities such as endobronchial laser resection. Of the patients, 65% had a squamous cell carcinoma. Endobronchial HDR brachytherapy results in few acute complications and can be performed with no major discomfort on an outpatient basis. In approximately 66% of patients, a palliative effect is achieved, even after the exhaustion of conventional treatment. Life may be prolonged for a few months, but the enhancement of survival is difficult to assess for several reasons. Mean survival is 9 months for limited disease and 5 months for extensive disease. Endobronchial HDR brachytherapy influences the pattern of failure: a 21% rate of fatal hemorrhages is probably the result of the selection of patients for this treatment rather than a treatment-related complication. There is sufficient evidence to suggest the rational use of HDR brachytherapy in combination with EBRT to effect a cure, or even on its own when tumor growth is strictly limited. However, the standardization of radiotherapy and endoscopic indications is an urgent priority. Prospective, controlled, and cooperative studies are mandatory. Endobronchial iridium-192 HDR brachytherapy complements endobronchial laser resection and is currently an established technique in the treatment of advanced malignant airway obstruction.