The impact of positioning errors on the dose distribution of hypofractionated radiotherapy for left-sided radical breast cancer

Purpose: To evaluate the impact of setup errors on the dosimetry of targets and organs at risk (OARs) in the mode of Hypofractionated radiotherapy(HFRT) for left-sided radical breast cancer, particularly on the esophagus, thyroid and left anterior descending artery (LAD). Methods: ), the heart, the LAD, the esophagus, and the thyroid under different setup errors. Results: (mean dose) of the esophagus, thyroid, LAD, heart, and ipsilateral lung increased by 2.24 Gy, 1.28 Gy, 1.57 Gy, 0.26 Gy, and 0.61 Gy, respectively. When the error increased to 9 mm, these increments further rose to 7.20 Gy, 4.59 Gy, 5.60 Gy, 1.29 Gy, and 2.34 Gy. Conclusion: may be relaxed to 5 mm.