2339 - Benefits of Regular Breath-Holding Training for DIBH Treatment

H. Li¹, F. Zhang², and J. Qiu³; ¹Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Shuaifuyuan Wangfujing, Dongcheng District, Beijing 100730, China, Beijing, China, ²Department of radiation oncology, Peking Union Medical College Hospital. Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China, ³Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China

Purpose/Objective(s): Deep inspiration breath-hold (DIBH) can reduce heart dose in patients undergoing breast radiotherapy. Therefore, stable and relatively long times of breath-holding are necessary, This study is to assess the clinical benefits of regular breathing training for treatment requiring DIBH. Materials/

Methods: Twenty-five patients with cancer of the left breast received regular breathing training and twenty-five controls did not. Data on breath-holding time, set-up time for radiotherapy in training group and treatment time of two groups, were collated. Breath-holding time data are presented as mean values. Treatment time and setup error were presented as median and percentile. Breath-holding stability and repeatability was analyzed by comparison of 6DoF real-time deltas (RTD) of a motion tracking system at the set-up, X-Ray Volume Imaging (XVI) and treatment stages. Differences in each direction were evaluated by nonparametric Wilcoxon rank test with a two-tailed p-value <0.05 was considered statistically significant.
Results: A gradual increase in the duration of breath-holding was seen with regular training and set-up time decreased from > 5 minutes for the first time to about 3 minutes for the fifth time. The median (quartile) treatment duration of the trained group was 229 (196.5-260)s compared with 298 (249-363)s for controls (p <0.05). Median (maximum quartile) for 3DoF results of a motion tracking system and XVI were 0.02 (0.085)/0.02 (0.115) in the vertical (VRT), 0.04 (0.13)/0 (0.1) in the longitudinal (LNG) and 0.04 (0.04)/0.04 (0.15) in the latitudinal (LAT) directions with no significant differences found. Median (maximum quartile) values for setup, XVI and treatment were 0.02 (0.085)/0.04 (0.15)/0.01 (0.1) in the VRT, 0.04 (0.13)/0.02 (0.11)/0.01 (0.14) in the LNG, 0.04 (0.15)/0.03 (0.12)/0.05 (0.14) in the LAT, 0.3 (1)/0.06 (0.85)/0.1 (1.3) in the Yaw, 0.3 (1)/0.1 (0.58)/0.3 (1) in the Roll and 0.05 (1)/0.3 (0.98)/0.2 (0.9) in the Pitch directions with no significant differences.
Conclusion: Motion tracking system and XVI give similar results in response to setup errors which may inform clinical use of XVI. Regular training improves patients breath-holding stability and repeatability, increases cooperation, enhances doctor-patient relationships and reduces treatment time. The performance of 3 breath-holds to ensure breath-holding stability during setup is recommended for fine-tuning and verification.