Abstract:Objective: To analyze the preoperative radiotherapy process in patients with rectal cancer, 3D-CRT and IMRT plan to treat the target area and the proximity of sensitive organs to receive the difference in irradiation dose.Methods: Twenty-one rectal cancer patients hospitalized in our department (chemotherapy center) from 2017 to 2018.Scan the CT image of the affected area and delineate the target area and adjacent sensitive organs. The total dose is 5000CGy. Design 3D-CRT and coplanar and other wild IMRT plans to evaluate HI (uniformity), CI (conformity), (Dmax) maximum exposure dose, (Dmin) minimum exposure dose, (Dmean) average The exposure dose and the exposure V (volume) of the adjacent sensitive organs were obtained and compared. Results: The 3D-CRT was worse than the target conformation of 5F-IMRT, 7F-IMRT, and 9F-IMRT; the IMRT was significantly better than the 3D-CRT for the adjacent sensitive organs, P<0.05. Conclusion: For the radiotherapy of patients with rectal cancer, the 3D-CRT plan is significantly worse than the IMRT plan in both the conformality and the protection of the adjacent sensitive organs. According to the comprehensive evaluation of all aspects, 5F is better than 7F and 9F. Not only is it efficient and reduces the economic burden of patients, it is clinically worthy of adoption.