Comparison Of Dosimetry To Different Radiotherapy Plans Of Breast-conserving Patients With Breast Carcinoma

Objective:The study is designed to evaluate the dosimetry differences in the target organs and normal tissue and organs of breast-conserving patients with breast carcinoma who are treated with different radiotherapy plans, in order to find the best clinical therapeutic scheme. Materials and Methods:14 breast-conserving patients with breast carcinoma received four radiotherapy planning respectively including conventional tangent radiotherapy(CRT),three-dimensional conformal radiotherapy (3D-CRT),intensity modulated radiation therapy (IMRT) and hybrid intensity modulated radiation therapy (Hybrid IMRT) which designed with three-dimensional treatment planning system. The prescription dose was 50Gy. Compare the radiation dose of target volume and normal organs,dose distribution and conformal index in dose-volume histogram (DVH). Results:V90 is the same in the four radiotherapy planning. There is a great difference between the highest and the lowest dose in the conventional planning of target organ, the target dose conformity and the dosimetric uniformity is the worst during the four planning. Hybrid IMRT planning reduced the maximum dose of PTV (V105% and V110%) significantly and has the best dosimetric uniformity. In the four planning, the target dose inhomogeneity index (HI) is CRT>3D-CRT>IMRT>Hybrid IMRT, and the plan conformal index (CI) is IMRT>Hybrid IMRT>3D-CRT>CRT. CRT<3D-CRT