Primary retroperitoneal tumors are those that originate in the retroperitoneal space but do not include retroperitoneal parenchymal organs and metastatic tumors[1]Because the tumor here is surrounded by many important organs such as kidney, spinal cord and blood vessels, it is not very suitable for surgery, which affects the quality of life of patients and becomes an important factor restricting surgery[2]Therefore, radiotherapy has become one of its first choice of adjuvant therapy. At present, radiotherapy is the most important local treatment for retroperitoneal tumors[1]However, the effect of radiotherapy is not satisfactory, and other complications such as radiation myelitis and nephritis after radiotherapy become factors affecting the quality of life of patients. In this study, the non-coplanar radiation field was applied to the retroperitoneal IMRT program, and the dose of the five-field common coplanar radiation field program was compared with the five-field non-coplanar radiation field program. The advantages of non-coplanar radiation field in reducing the exposure dose of kidney and spinal cord and increasing the dose of target area were studied, so as to provide a theoretical basis for the wide application of non-coplanar radiation field IMRT in body tumor radiotherapy.
