Program Information
Different Breathing Maneuvers for DIBH During Radiotherapy for Left-Sided Breast Cancer
F ZHAO*, Z Lu , G Yao , S Yan , the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang
Presentations
SU-I-GPD-T-511 (Sunday, July 30, 2017) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose: Deep inspiration breath hold (DIBH) is an effective technique for reducing the cardiac dose during left-sided breast cancer radiotherapy (RT). However, DIBH can be performed using different breathing maneuvers, including DIBH with a thoracic breathing maneuver (T-DIBH) and DIBH with an abdominal breathing maneuver (A-DIBH). The purpose of this study is to quantify which type of DIBH can achieve more benefits in terms of reducing the doses to organs at risk, without compromising the target coverage.
Methods: Twenty-two patients were enrolled in this study. The parameter of average surface distance (ASD) was introduced to quantitatively evaluate the relative spatial distance between the left anterior descending artery (LAD) and the breast clinical target volume (CTV) during different breathing maneuvers. Additionally, dose-volume histograms were calculated and compared.
Results: Compared with T-DIBH, the mean ASD between the LAD and the breast CTV for A-DIBH was increased from 25.25±4.09 mm to 29.31±5.51 mm (p<0.0001). Compared with T-DIBH, A-DIBH achieved lower cardiac, LAD and pulmonary doses, with equal coverage of the planning target volume. The mean heart dose, LAD dose and ipsilateral lung dose were reduced from 1.63 Gy to 1.38 Gy (p=0.001), from 13.39 Gy to 9.70 Gy (p=0.0043), and from 7.54 Gy to 7.08 Gy (p=0.0124), respectively. Linear regression analyses showed that the ASD was negatively correlated with the mean dose to the LAD (r= -0.633, p<0.05), and the heart (r= -0.481, p<0.05).
Conclusion: This quantitative spatial distance and dosimetric comparison study indicated that A-DIBH had better outcomes than T-DIBH. A-DIBH should be incorporated into the daily routine for left-sided breast RT.
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