Introduction:Radiotherapy is a standard treatment of breast cancer after complete surgery.The curved surface of the breast and the geometry that is laid near the critical organs,treatment techniques for the breast radiotherapy have to be considered for the dose homogeneity and the improvement of the conformity to the target volume.Objective:The purpose of this study is to compare the homogeneity index and conformity index between four treatment techniques in breast radiotherapy clinical cases.Materials and Methods:The four treatment planning techniques,standard wedged tangent(SWT),electronic compensator(E Comp),intensity modulated radiation therapy(IMRT),and volumetric modulated arc therapy(VMAT),were investigated for nine breast conserving surgery cases from Eclipse treatment planning system(TPS).The doses of D2%,D50%and D98%were recorded to calculate the homogeneity index(HI)according to ICRU 83.For the conformity index(CI)calculation the treated volume(TV)and the planning target volume(PTV)were recorded.Results and Discussion:The homogeneity index was significantly improved in IMRT(0.12±0.03)and E Comp(0.13±0.02),while VMAT(0.15±0.03)technique was comparable in homogeneity index with SWT(0.15±0.02).The conformity index showed the best result in IMRT(1.03±0.08)and VMAT(0.99±0.14)in all four techniques.SWT(1.68±0.27)technique was the worse result in conformity index due to no beam modulation in 3D breast shape.E Comp(1.29±0.17)showed better results in CI than SWT.Conclusion:IMRT and E Comp were the best techniques to treat the breast cancer,according to HI and CI results.However,E Comp cannot control the dose to the organ at risk like IMRT,using optimization dose constraints.In contrast,the planning time for the IMRT is significantly higher than E Comp and need the well trained planner.