COMPARATIVE ANALYSIS OF RADIATION DOSES ON HEART WHEN USING VARIOUS 3D PLANNING METHODS

Background. Malignant neoplasms of the mammary gland represent the most numerous groups in terms of morbidity and mortality among women of the Republic of Belarus. The most formidable complication of radiation therapy for breast cancer is heart complications. Aim of the study is to compare the dose loads on the heart when creating radiation treatment plans for left breast cancer with the inclusion of regional lymph nodes using two 3D planning methods in a standard position on the back with free breathing. Material and methods. The research included dosimetric plans for the treatment of left breast cancer in 20 patients after radical mastectomy with lymph node dissection. The tangential planning method with separation of radiation volumes in the isocenter was compared with the planning method without separation of radiation volumes, including the fields in the projection of which the heart is located. Results. The best indices for the heart in terms of average (Dmean) and minimum (Dmin) doses were obtained using the tangential planning method with separation of radiation volumes in the isocenter (4.26 Gy, 0.6 Gy, respectively). Conclusion. Irradiation of left breast cancer by tangential planning with separation of radiation volumes in the isocenter contributed to a statistically significant decrease in dosimetric parameters: Dmean and Dmin