High-dose-rate brachytherapy for airway malignancy a single institution experience.

PURPOSE: To evaluate clinical outcomes of endobronchial malignancy treated using high-dose-rate endobronchial brachytherapy (HDREB). METHODS AND MATERIALS: A retrospective chart review was conducted for all patients treated with HDREB for malignant airway disease between 2010 and 2019 at a single institution. Most patients had a prescription of 14 Gy in two fractions given a week apart. The Wilcoxon signed rank test and paired samples t test were used to compare changes in mMRC dyspnea scale prior to and after brachytherapy at first followup appointment. Toxicity data were collected for dyspnea, hemoptysis, dysphagia, and cough. RESULTS: A total of 58 patients were identified. Most (84.5%) had primary lung cancer with advanced cancers, stage III or IV (86%). Eight were treated while admitted in the ICU. Previous external beam radiotherapy (EBRT) was received by 52%. An improvement in dyspnea was seen in 72%, with an mMRC dyspnoea scale score improvement of 1.13 points (p < 0.001). Most (22, 88%) had an improvement in hemoptysis and 18 out of 37 (48.6%) had an improvement in cough. Grade four to five events occurred in 8 (13%) at the median time of 2.5 months from brachytherapy. Twenty-two patients (38%) had complete obstruction of the airway treated. Median progression free survival was 6.5 months and median survival was 10 months. CONCLUSIONS: We report a significant symptomatic benefit among patients receiving brachytherapy with endobronchial malignancy, with rates of treatment related toxicities similar to prior studies. Our study identified new subgroups of patients, ICU patients & those with complete obstruction, who benefited from HDREB.

Automatic needle detection using improved random sample consensus in CT image-guided lung interstitial brachytherapy.

PURPOSE: To develop a method for automatically detecting needles from CT images, which can be used in image-guided lung interstitial brachytherapy to assist needle placement assessment and dose distribution optimization. MATERIAL AND METHODS: Based on the preview model parameters evaluation, local optimization combining local random sample consensus, and principal component analysis, the needle shaft was detected quickly, accurately, and robustly through the modified random sample consensus algorithm. By tracing intensities along the axis, the needle tip was determined. Furthermore, multineedles in a single slice were segmented at once using successive inliers deletion. RESULTS: The simulation data show that the segmentation efficiency is much higher than the original random sample consensus and yet maintains a stable submillimeter accuracy. Experiments with physical phantom demonstrate that the segmentation accuracy of described algorithm depends on the needle insertion depth into the CT image. Application to permanent lung brachytherapy image is also validated, where manual segmentation is the counterparts of the estimated needle shape. CONCLUSIONS: From the results, the mean errors in determining needle orientation and endpoint are regulated within 2° and 1 mm, respectively. The average segmentation time is 0.238 s per needle.