High dose rate endoluminal brachytherapy in the treatment of endobronchial lesions - experience of a single institution and literature review.

Purpose: To evaluate the efficacy and toxicity of Iridium-192 high-dose-rate endobronchial brachytherapy (HDR-EBT) for palliation of symptoms and for curative intent.

Material And Methods: This is a retrospective study of a prospectively registered cohort of 31 patients with endobronchial lesions treated with HDR-EBT at our institution between 2008 and 2020. Eighteen patients were treated with palliative intent and 13 curative intent; 4 of them as a boost to external radiation therapy (XRT). The primary objectives of the study were to analyze the symptomatic relief, endoscopic response, and treatment-related toxicity. As a secondary endpoint, survival analyses were performed.

Results: In palliative setting, most of the symptomatic patients (80%) presented a significant clinical improvement and 75% presented endoscopic improvement of the lesions. In curative setting, all patients with visible lesions had endoscopic improvement and better survival than palliatively treated patients (median: 78 and 9 months, respectively; p = 0.002). There were no complications in 91.4% of the treatments: only one pneumonia, one pneumothorax and one bronchial stenosis occurred, all in palliative treatments. No fatal hemoptysis happened. Acute toxicity was mild (G ≤ 2) and transitory.

Discussion: HDR-EBT is an excellent, safe, and inexpensive palliative treatment of symptoms caused by endobronchial growth of tumors in the proximal airway, either as a single treatment or in combination with XRT. It can also be an alternative in the treatment of initial malignant tumors when surgery or XRT is not possible, and it may also play a role in treating non-malignant bronchial obstructions.