Endobronchial brachytherapy with curative intent: the impact of reference points setting according to the bronchial diameter

Endobronchial brachytherapy (ebb) is an effective treatment for endobronchial tumors. however,bronchial toxicity caused by over-irradiation remains problematic. to decrease bronchial toxicity,we developed a sourcecentralizing applicator for ebb. the purpose of the present study was to assess the efficacy and safety of ebb with varying reference dose points according to the bronchial diameter,using a source-centralizing applicator. we reviewed 15 patients with endobronchial carcinoma who were treated with curative intent using a combination of external beam radiotherapy (ebrt) and high-dose-rate ebb between 2005 and 2014. during each ebb session,we used a source-centralizing applicator that maintained the source-delivering catheter in the center of the bronchial lumen. reference dose points were 5-7 mm from the source axis,depending on the bronchial diameter. the median radiation doses of ebrt and ebb were 40 gy in 20 fractions and 18 gy in 3 fractions,respectively. the median observation period was 36 months. the 3-year overall survival,progression-free survival and local control rates were 79%,77% and 100%,respectively. grade 2 radiation pneumonitis was observed in two cases. bronchial toxicities,such as hemoptysis or the symptoms of chronic bronchitis,were not observed. ebb with varying reference dose points according to bronchial diameter,using a source-centralizing applicator,is a promising procedure that may be effective for tumor elimination and reducing toxicity to the bronchial wall. © the author 2017.