Comprehensive analysis of the role of deep inspiration breath-hold in right-sided breast cancer radiotherapy: A focus on cardiac substructures and right coronary artery.

PURPOSE

The deep inspiration breath-hold (DIBH) technique, a method used to minimize radiation exposure to normal tissues in breast cancer patients, has primarily been applied to patients with left breast cancer. However, this study, with its unique focus on right breast cancer, aims to evaluate the potential benefits of DIBH on the right coronary artery (RCA), cardiac substructures, and liver dose in right breast cancer radiotherapy.

MATERIALS AND METHODS

Forty right-sided breast cancer patients were included in this study. Radiotherapy planning using 3D, IMRT, and VMAT was performed using both free-breathing (FB) and DIBH techniques. Two treatment plans were generated per patient, and organ-at-risk (OAR) doses were compared using the Wilcoxon signed-rank test. Patients were analyzed based on regional nodal irradiation (RNI) status.

RESULTS

The mean radiation doses (Dmean) to the liver, ipsilateral lung, heart, and RCA region were 5.4, 15.9, 2.5, and 6 Gy with FB, decreasing to 4.6, 12.6, 1.6, and 3.6 Gy with DIBH. For the left ventricle, right ventricle, left atrium, and right atrium, the Dmean values were 1.2, 2.2, 2, and 4.6 Gy with FB, versus 0.76, 1.8 Gy, 1.2, and 3.2 Gy with DIBH. DIBH significantly reduced liver and lung doses in all patients, while heart and RCA doses reductions were observed only in those receiving RNI.

CONCLUSION

The use of the DIBH technique can significantly reduce radiation exposure to OARs in right-sided breast cancer radiotherapy. Despite a slight increase in treatment duration, DIBH should be considered for right breast cancer radiotherapy to minimize radiation-related toxicity.