2105 - A Clinical Trial on Respiratory Training Device (RESPEDUE) for Improving DIBH Radiotherapy in Breast Cancer
Presenter(s)
Y. Huh1,2, J. H. Chang1,3, H. Jin1,2, H. G. Wu1,3, C. H. Choi1,2, J. I. Kim1,2, and J. Son1,2; 1Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea, Republic of (South), 2Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea, Republic of (South), 3Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea, Republic of (South)
Purpose/Objective(s): Breast cancer radiotherapy poses a risk of cardiac toxicity, particularly affecting the left anterior descending artery, which may increase the likelihood of myocardial infarction. The Deep Inspiration Breath Hold (DIBH) technique reduces cardiac radiation exposure by increasing lung volume and minimizing the heart’s radiation dose. However, successful DIBH depends on patient cooperation, and limited breath-holding capacity can compromise treatment efficacy. This study aims to assess the feasibility of a novel respiratory training device, RESPEDUE, in enhancing DIBH performance for improved radiotherapy outcomes.
Materials/Methods: Nine participants (mean age: 47.9 years) were enrolled. Among them, six had left breast cancer, five had right breast cancer, and two received treatments for both. Radiotherapy was delivered in 16 fractions (Fx) for seven patients, 18 Fx for one, and 20 Fx for another. Participants used RESPEDUE (PaprikaLab Inc., Republic of Korea), a respiratory training device comprising a tension sensor and a tablet PC with software. The device measured chest elevation and transmitted breath-holding data via Bluetooth. Training lasted about seven days before CT simulation, and treatment plans were based on training outcomes. To assess RESPEDUE’s effectiveness, breath-holding duration (minimum, and maximum) was measured during training and treatment. Treatment efficacy was evaluated by analyzing lung volume and heart-to-target distance in CBCT images using oncology imaging informatics system software and in-house Python code. Dose to organs at risk (OARs) was assessed using lung V20 and heart V5 and Dmean values.
Results: After seven days of training, all nine participants were able to hold their breath for at least 20 seconds, showing an approximately 2.92-fold improvement compared to their minimum initial breath-holding duration. During treatment, all participants maintained breath-holding for at least 20 seconds, with an average duration of 27.76 ± 2.47 seconds. Lung volume fluctuated by an average of 4.39 ± 2.3% throughout the treatment period. The distance between the heart and target volume remained stable at an average of 1.5 ± 0.83 mm. Regarding radiation dose to organs at risk (OARs), the average Lung V20 was 19.65 ± 1.31%, while the average Heart V5 and Dmean were 29.33 ± 1.75 % and 4.99 ± 0.15 Gy, respectively.
Conclusion: While the study shows promise, its limited sample size restricts the generalizability of results. Recruiting more patients would enable a quantitative assessment of the reduction in cardiac radiation dose with DIBH radiotherapy using RESPEDUE. The RESPEDUE device shows promise in enhancing the efficacy of DIBH radiotherapy by extending breath-holding times, thereby reducing cardiac radiation exposure. This improvement can lead to better treatment outcomes and lower cardiac toxicity risks in breast cancer radiotherapy.