Active Breathing Coordinator reduces radiation dose to the stomach in patients with left breast cancer

Abstract

Background/Purpose

Gastric dose parameters comparison for deep inspiration breath-hold (DIBH) or free breathing (FB) mode during radiotherapy (RT) for left-sided breast cancer patients (LSBCPs) has not been investigated before. This study aimed to analyze the impact of Active Breath Coordinator (ABC)-DIBH technique on the dose received by the stomach during RT for LSBCPs and to provide organ-specific dosimetric parameters.

Materials and methods

The study included 73 LSBCPs. The dosimetric parameters of the stomach were compared between FB and DIBH mode. The correlation between the stomach volume and dosimetric parameters was analyzed.

Results

Compared to FB mode, statistically significant reductions were observed in gastric dose parameters in ABC-DIBH mode, including Dmax (46.60 vs 17.25, p < 0.001), D1cc (38.42 vs 9.60, p < 0.001), Dmean (4.10 vs 0.80, p < 0.001), V40Gy (0.50 vs 0.00, p < 0.001), V30Gy (6.30 vs 0.00, p < 0.001), V20Gy (20.80 vs 0.00, p < 0.001), V10Gy (51.10 vs 0.77, p < 0.001), and V5Gy (93.20 vs 9.60, p < 0.001). ABC-DIBH increased the distance between the stomach and the breast PTV when compared to FB, from 1.3 cm to 2.8 cm (p < 0.001). Physiologic decrease in stomach volume was not found from FB to ABC-DIBH (415.54 cm³ vs 411.61 cm³, p = 0.260). The stomach volume showed a positive correlation with V40Gy (r² = 0.289; p < 0.05), V30Gy (r² = 0.287; p < 0.05), V20Gy (r² = 0.343; p < 0.05), V10Gy (r² = 0.039; p < 0.001), V5Gy (r² = 0.439; p < 0.001), Dmax (r² = 0.269; p < 0.05) and D1cc (r² = 0.278; p < 0.05) in FB mode. While in ABC-DIBH mode, most stomach dosimetric parameters were not correlated with gastric volume.

Conclusions

The implementation of ABC-DIBH in LSBCPs radiotherapy resulted in lower irradiation of the stomach. Larger stomach volume was associated with statistically significantly higher dose irradiation in FB mode. To reduce radiotherapy related side effects in FB mode, patients should be fast for at least 2 hours before the CT simulation and treatment.

Keywords:

• Left-sided breast cancer
• radiotherapy
• stomach dose
• stomach volume
• ABC-DIBH

Author contributions

Y. Piao and H. Chen contributed equally to this work.

D Yang is the guarantor of integrity of the entire study. D Yang, H Chen and Y Piao were responsible for study concepts and design. H Chen and Y Piao were responsible for the clinical studies. D Yang and F Yuan carried out the experimental studies/data analysis. F Yuan carried out the statistical analysis. Y Piao, J Fan and S Wu prepared the manuscript. X Li and D Yang edited the manuscript.

Data availability statement

The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.