Work

Dosimetric benefits of deep inspiration breath-hold in postoperative radiotherapy for left-sided breast cancer after breast-conserving surgery: an anatomical parameter-based analysis

Year: 2026

Type: article

Abstract: Objective: To investigate the dosimetric impact of deep inspiration breath-hold (DIBH) technique on radiotherapy after breast-conserving surgery for left-sided breast cancer, and to explore the relationship between patient anatomical characteristics and dosimetric benefits of DIBH, providing preliminary evidence for understanding individual differences in DIBH related dosimetric gains and their personalized application. Methods: This retrospective study included 17 patients who underwent postoperative radiotherapy after breast-conserving surgery for left-sided breast cancer. All patients underwent computed tomography (CT) simulation under both DIBH and free-breathing (FB) conditions, and intensity-modulated radiation therapy (IMRT) plans were generated from both image sets. With identical prescription doses and planning optimization objectives, dosimetric parameters for the left lung, heart, and cardiac substructures were compared between the two respiratory conditions. Correlations of the maximum cardiac margin distance (MCMD), cardiac displacement, cardiac displacement volume, heart-to-breast distance (HBD), and changes in lung volume with dosimetric parameters were also analyzed. Results: < 0.05). Correlation analysis demonstrated that MCMD under the DIBH condition was positively correlated with cardiac Dmean. The change in MCMD between DIBH and FB was negatively correlated with cardiac and ventricular dose parameters. Cardiac displacement volume between the two respiratory states was positively correlated with changes in mean heart dose. Further analysis revealed that changes in lung volume were positively correlated with cardiac displacement along the Z-axis and changes in HBD while negatively correlated with LAD Dmean under the DIBH condition. Conclusion: DIBH can reduce radiation exposure to the left lung, heart, and selected cardiac substructures while satisfying target-dose requirements. Exploratory analyses indicated that cardiac geometric parameters and changes in lung volume were associated with selected dosimetric parameters, suggesting that dynamic anatomical changes during DIBH may help explain interindividual differences in dosimetric benefit. These findings require further validation in larger, multicenter cohorts.

Source: Frontiers in Oncology

DOI: 10.3389/fonc.2026.1917416