Features of radiotherapy planning on pelvic organs cancer in patiens with hip joint endoproshetics

Background. The purpose of the study is to evaluate different types of radiation therapy planning for rectal cancer in a patient with a previously prosthetic hip joint. Material and methods. In the present study, to compare the quality of delivery and distribution of the radiation dose during radiation therapy, four individual plans were used, performed in various methods on the basis of CT-topometric data of a patient with an arthroplasty of the hip joint and a tumor of the rectum. The evaluation used the calculation of the planned volume of exposure (Planning Target Volume ‒ PTV), which included the rectum, pararectal and presacral tissue, as well as internal iliac lymph nodes. Results. The worst dose quality was shown by the conventional 2D radiotherapy plan. All multifield modes showed sufficient dose distribution in the planned volume, a high degree of homogeneity and conformity, a higher integral (volume) dose per endoprosthesis was noted. 3D conformal radiotherapy and IMRT showed similar results, the best results are noted in the VMAT plan. Conclusion. According to the results of our analysis, if radiotherapy to the pelvic organs is required in patients with a hip prosthesis, VMAT technology is preferable, and in its absence, IMRT or 3D-conformal radiotherapy.