Abstract
Relevance: Breast cancer is one of the most common oncological diseases. Today, it leads among female cancers. Patients with left breast cancer undergoing radiation therapy have a considerable risk of developing cardiovascular diseases caused by ionizing radiation. Various methods are introduced to reduce the radiation load to critical organs to ensure compliance with the main radiation therapy principle. One of these methods is radiation therapy with synchronized breathing, including deep inspiration breath-hold (DIBH). DIBH can significantly reduce the dose load to the heart and the left lung. The study aimed to compare the radiation load to the heart and the left lung during radiation therapy for left breast cancer with free breathing and respiratory synchronization. Results: During radiation therapy with synchronized breathing, the average radiation load to the heart is 1.7 times lower and to the left lung – 1.26 times lower compared to radiation therapy with free breathing. Conclusion: The study results confirm that respiratory synchronization in radiation therapy for left breast cancer reduces the dose to the heart and the left lung.